Search Results (4,719)

The corrosion phenomenon can cause negative allergic and cytotoxic reactions in the human body, inflammation, and, in the future, the development of cancer. Their sources may be corrosion products, metal ions released during the corrosion process, and galvanic currents that penetrate the surrounding tissues. In order to avoid the negative effects of using metal alloys, their surface can be modified by applying coatings. The aim of this study is to determine and compare the amount of ion release from Si(C,N) coatings with varying carbon and nitrogen contents, as well as from the uncoated substrate alloy (Group A) in various aqueous environments. Si(C,N) coatings were applied to the surface of the prosthetic alloy. Si(C,N) coatings with different carbon and nitrogen contents were deposited using the reactive magnetron sputtering (RMS) method. The research included determining the amount of ions released into the environment: distilled water, 0.9% NaCl and artificial saliva. Assessments were made at 10, 30 and 90 days. All tested Si(C,N) coatings significantly limit the amount of metal ions in the surrounding medium. Due to the lack of statistically significant differences in the number of ions released by individual coatings, when selecting them, other properties related to the operating conditions of the elements should also be taken into account. Full article

Rapid urbanization in tropical Asia has led to a critical loss of green cover, exacerbating urban environmental challenges. While green roofs offer a promising Nature-based solution, their implementation in Asian countries is hindered by the prevalence of sloped roofs and high structural conversion costs. This research addresses this gap by developing a novel, lightweight vegetative roof tile designed as a direct structural replacement for conventional roofing materials in Sri Lanka. Existing roofing systems were studied, followed by a laboriousness study to determine the optimum tile dimensions. To meet these requirements, a modular tile measuring 900 mm × 1200 mm with a wave-shaped corrugated profile (a 10 mm rise and a 200 mm pitch) was engineered using SolidWorks 2024 and ABAQUS 2024 to meet Eurocode standards. Field investigations into plant health helped to finalize the depth of the roof tile as 2.5 cm. Following root penetration testing, fiber-reinforced plastic was selected for the tile structure to ensure durability while maintaining a total saturated weight of 52.5 kg/m². Biological testing demonstrated robust greening performance, with Axonopus compressus and Zoysia matrella achieving 100% survival rates and over 80% canopy coverage. This design methodology can be adapted across tropical Asia, contributing significantly to regional green infrastructure development and sustainable building practices. Full article

In impact testing, evaluating multiple-impact signals is critical for verifying whether a test setup can reproduce penetration response signals and ensure reliable results. To overcome the limitations of traditional methods, including incomplete indicator coverage, subjective weighting, and poor consistency, this study proposes a fuzzy comprehensive evaluation (FCE) framework based on time–frequency features and combined weighting. Using multi-layer penetration response signals as the matching target, a multidimensional indicator system covering time-domain features, frequency-domain features, and signal quality and stability is established. A combined weighting method integrating AHP, EWM, and CRITIC is then developed, and subjective and objective weights are fused using the geometric mean method. A fuzzy comprehensive evaluation model is used to quantify the matching degrees of multiple sets of multiple-impact signals, and robustness is verified through weight consistency tests and sensitivity analysis. The results show that the evaluated signal sets are rated “Excellent”. Under reasonable weight combinations, the probability of obtaining an “Excellent” result reaches 99.94%, and the maximum variation caused by a ±10% perturbation in a single indicator weight is only 0.0087. The proposed framework provides a practical tool for evaluating multi-layer penetration response simulations and can be extended to other complex dynamic signal-matching problems. Full article

Drilling in deep hard formations poses significant challenges for conventional polycrystalline diamond compact (PDC) cutters, which often suffer from low rock-breaking efficiency and premature failure due to severe cutter-face wear, high thermal loads, and stick-slip vibrations. To overcome these limitations, this study proposes a chisel-shaped PDC cutter and systematically investigates its rock-breaking and thermal characteristics. A coupled temperature–displacement finite element model (FEM) of cutter–granite interaction and a single-cutter indentation model were developed based on elastoplastic mechanics and the Drucker–Prager failure criterion. The rock constitutive parameters used in both models were validated through uniaxial compression tests. Using these models, the influences of cutter shape, back rake angle, and depth of cut (DOC) were analyzed. Compared with a conventional cylindrical cutter, the chisel cutter reduces the cutting force by 13.4% and the axial penetration reaction force by 22%. The cutting force of the chisel cutter remains consistently lower across all tested depths. The optimal back rake angle is 20–25°, and the optimal DOC is 1.5 mm. Full-bit simulations further demonstrate that the chisel-cutter bit creates a more concentrated bottomhole stress field, increases the rate of penetration (ROP) by 19.7%, reduces average torque by 11.34%, and produces smoother torque fluctuations, indicating higher drilling stability. Thermal analysis reveals that the chisel cutter exhibits lower and more stable cutter-face temperatures. Both simulation and experimental results confirm that the chisel design reduces the friction contact area between cuttings and the cutter face, thereby lowering temperature accumulation. Field drilling data corroborate the reliability of the conclusions. These findings provide guidance for the design of PDC bits intended for deep hard formations. Full article

In order to clarify the controlling effects of tectonic activity on hydrocarbon migration efficiency in the Permian–Triassic strata of the Luzhou area, Sichuan Basin, this study takes faults as the research objective. Using 3D seismic data, tectonic evolution records, and single-well test data, we systematically analyze the geometric characteristics, activity phases, classification by grade and type, and reservoir-controlling effects of faults. The results show that a total of 843 reverse faults have been identified in the study area. The major faults are distributed in a NE-SW trend, with eight planar combination styles developed, and the main cross-sectional styles are back-thrust and “Y”-shaped types. The faults experienced four phases of tectonic activity: Caledonian, Hercynian, Indosinian, and Yanshan–Himalayan. Among these, the Indosinian phase is the key formative phase, effectively connecting the source rocks and reservoirs. The faults are classified into three grades and four categories: source-connected faults, reservoir-modifying faults, damaging faults, and source-connected and damaging faults. Migration efficiency is jointly controlled by fault grade, activity phases, and the penetrated formations. Among them, third-order source-connected faults formed during the Indosinian phase exhibit the highest migration efficiency, while first-order damaging faults formed during the Yanshan phase tend to cause hydrocarbon dissipation. This study can provide a reference for hydrocarbon exploration and the prediction of favorable areas in the Luzhou area. Full article

Persistent organic contaminants and complex wastewater matrices challenge conventional treatment because parent-compound removal does not necessarily imply mineralization, detoxification, or improved environmental safety. Advanced oxidation processes can address these limitations, but practical effectiveness is often constrained by oxidant activation, gas–liquid mass transfer, reagent distribution, light penetration, catalyst contact, energy demand, and matrix scavenging. This work critically examines hydrodynamic cavitation-assisted advanced oxidation processes for water and wastewater treatment, including systems based on hydrogen peroxide, ozone, Fenton and Fenton-like reactions, persulfate, peroxydisulfate, peroxymonosulfate, UV irradiation, photocatalysis, cold plasma, multi-hybrid configurations, and emerging reduction-oriented approaches. The discussion covers reactor configurations, target contaminants, real matrices, and sustainability-related performance metrics. The central argument is that hydrodynamic cavitation is not automatically sustainable as a stand-alone treatment. It becomes relevant as a sustainable intensification module only when measurable improvements are demonstrated in oxidant activation, mass transfer, treatment depth, biodegradability, toxicity reduction, process integration, or scale-up at acceptable energy and chemical cost. A reporting framework is proposed based on mineralization, COD/TOC reduction, by-products, toxicity, biodegradability, normalized energy consumption, chemical efficiency, real-matrix validation, reproducibility, and cost-relevant indicators. Future progress should move from isolated degradation tests to integrated, controllable, and scalable treatment frameworks. Full article

Demand response (DR) plays a key role in enhancing power system flexibility under increasing renewable penetration, yet most existing approaches rely on aggregate demand models that fail to capture appliance-level heterogeneity. A bilevel programming framework for DR incentive design incorporating non-intrusive load monitoring (NILM)-based flexibility estimation is proposed. A conditional factorial hidden Markov model (CFHMM) is used to disaggregate smart meter data and recover appliance-level consumption patterns, which are then mapped to willingness-to-accept (WTA) values to construct device-informed DR potential functions. These estimates are embedded in a bilevel optimization model, where a retailer determines optimal incentives while accounting for the endogenous impact of demand response on locational marginal prices through market clearing. The model is reformulated as a single-level mixed-integer linear program using Karush–Kuhn–Tucker (KKT) conditions. Case studies using real-world data and the IEEE test system show that the proposed framework produces more effective incentive strategies than aggregate DR modeling, leading to improved DR utilization and higher retailer profitability. Full article

The development of age-appropriate pediatric dosage forms remains an important challenge, particularly for acid-labile drugs requiring gastro-resistant protection. Pantoprazole, a proton pump inhibitor, must be protected from gastric acid until intestinal absorption; however, conventional enteric-coated tablets may be difficult to use in younger children, while manipulation of dosage forms or mixing with food can compromise dose accuracy and drug release performance. Multiparticulate systems, such as minitablets, pellets, or granules, offer flexible dosing but may still require a suitable vehicle to improve acceptability, handling, and ease of swallowing. In this study, enteric-coated pantoprazole minitablets were developed and evaluated after dispersion in selected hydrogel vehicles intended to serve as standardized alternatives to food-based carriers. Hydrogels based on hypromellose (HPMC), carbomer (CAR), and sodium alginate (SA) were characterized in terms of pH, rheological properties, firmness, acid penetration, and their effect on pantoprazole release. Dissolution performance was assessed using both conventional pharmacopoeial testing and dynamic non-pharmacopoeial conditions. Low-concentration gels prepared from high-viscosity HPMC grades showed the most favorable performance, combining suitable spoonable consistency with limited impact on drug release. Among them, 5% HPMC 65SH4000 was particularly promising, as it did not markedly delay pantoprazole release in either pharmacopoeial or dynamic dissolution testing. CAR gels provided advantageous rheological properties, including high viscosity at rest and shear-thinning behavior, and allowed efficient pantoprazole release after transition to buffer conditions; however, their interaction with enteric-coated minitablets should be further optimized with respect to gel amount, concentration, and neutralization strategy. SA gel showed strong structural persistence and delayed release under pharmacopoeial conditions, although this effect was less pronounced in the dynamic model. Overall, the findings indicate that appropriately selected hydrogels may improve the practical use of pediatric multiparticulate formulations, but their composition, pH, rheology, and interaction with enteric coatings must be carefully evaluated. Full article

Polyester (PET) fibers are widely used to reinforce asphalt materials; however, their smooth and hydrophobic surfaces limit interfacial bonding and restrict their reinforcing efficiency. This study develops an eco-friendly surface modification method based on the chemical modification of gallic acid (GA) and aminosilane (KH792) to enhance the compatibility between PET fibers and asphalt. Modified fibers with various molar ratios of GA/KH792 were prepared and incorporated into asphalt mastic. Their performance was evaluated using softening point, cone penetration, dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), linear amplitude sweep (LAS), and bending beam rheometer (BBR) tests, combined with interfacial interaction analysis and scanning electron microscopy (SEM). The results show that surface modification significantly improves the reinforcing effect of PET fibers. In particular, the co-modified fiber with a GA/KH792 ratio of 1:1 exhibits the best performance, with increases of 27% in softening point and 105% in shear strength, as well as notable improvements in rutting resistance, fatigue performance, and temperature stability. Interfacial indices and SEM observations confirm enhanced adhesion, dispersion, and load transfer capacity. However, the improvement in low-temperature performance is limited. Overall, GA/KH792 chemical modification effectively enhances fiber asphalt interfacial interaction and provides a simple and sustainable approach for developing high-performance asphalt materials. Full article

Background and Objectives: Professional ballet dancers endure high occlusal loads, increasing cervical defect prevalence. Conventional composites fail frequently under such conditions. This randomized clinical trial (RCT) compared 24-month performance of a polymer-infiltrated ceramic network (PICN, VITA Enamic) versus a self-curing bioactive composite (Stela) for cervical restorations. Materials and Methods: Twenty professional ballet dancers (40 cervical defects: 21 carious, 19 abfraction) were enrolled in a paired split-mouth RCT. Each received one PICN inlay and one self-curing composite restoration on two non-adjacent defects. Restorations were assessed at 6, 12, and 24 months using United States Public Health Service (USPHS) criteria (primary: marginal integrity) and a dye penetration test. Secondary outcomes included secondary caries, hypersensitivity, and Oral Health Impact Profile-14 (OHIP-14). Statistical tests: McNemar, Fisher’s exact, Kaplan–Meier, log-rank (α = 0.05). Results: At 24 months, marginal integrity (USPHS Alpha) was maintained in 91% of PICN restorations for carious defects and 89% for abfraction defects, compared to 70% and 50% for self-curing composite, respectively. No PICN restoration failed (0%). Self-curing composite failures were 20% (carious) and 30% (abfraction) (exploratory uncorrected p = 0.031; non-significant after correction). Dye penetration was lower for PICN in abfraction defects (11% vs. 60%, adjusted p = 0.048) but not in carious defects (9% vs. 30%, adjusted p = 0.317). Kaplan–Meier survival favoured PICN (log-rank p = 0.001); 24-month survival probability: PICN 100% (95% CI: 83–100%), self-curing composite 75% (95% CI: 55–95%). No secondary caries or serious adverse events occurred. Conclusions: PICN hybrid ceramic provided superior marginal integrity and zero failures over 24 months in cervical restorations of professional ballet dancers, outperforming the self curing composite. Within this high-risk population, PICN inlays are recommended for abfraction defects. However, because the study was conducted exclusively in professional ballet dancers, direct extrapolation to the general population should be made with caution. The self-curing composite may be considered for carious defects when light curing is problematic, but patients should be informed of higher failure risk. Longer studies are needed. Full article

Corrosion of pipelines by flue gas desulfurization (FGD) wastewater compromises the normal operation of the desulfurization tower, and corrosion under high-chloride conditions in particular severely damages the tower’s internal structure. To further elucidate the corrosion mechanism at elevated Cl⁻ concentrations, the corrosion behavior of 20 steel exposed to high-chloride FGD wastewater at different Cl⁻ concentrations was investigated through weight-loss measurements, electrochemical tests, immersion corrosion experiments, composition analysis, and microscopic morphology characterization. The results revealed that higher Cl⁻ concentrations corresponded to lower corrosion rates: the corrosion rate reached 0.1964 mm/y in the absence of Cl⁻, but decreased to 0.1537 mm/y at a Cl⁻ concentration of 100,000 mg/L. XPS analysis showed that as the Cl⁻ concentration increased, the corrosion film gradually transformed from porous FeOOH into dense Fe₃O₄. Localized pitting analysis indicated a positive correlation between Cl⁻ concentration and pitting susceptibility. At Cl⁻ concentrations of 0 and 100,000 mg/L, the corrosion current density decreased from 32.44 μA/cm² to 6.43 μA/cm² after 72 h, decreasing by a factor of approximately 5.05. This behavior is attributed to the fact that Cl⁻ increases solution conductivity in high-chloride environments, thereby promoting the formation rate of the corrosion film. Additionally, high Cl⁻ levels reduce dissolved oxygen in the solution, causing the corrosion film to progressively react and form denser Fe₃O₄. Nevertheless, the high penetrability of Cl⁻ continues to aggravate pitting corrosion of 20 steel. Full article

Using solid wastes to fabricate sustainable backfill materials for mining engineering is crucial for environmental sustainability worldwide. In this study, the use of coal gangue aggregates as a sustainable alternative to natural aggregates in geopolymer gel backfill materials was explored, which contributes to green mining development. Through uniaxial compression tests, the effects of fine gangue content, mass concentration, and the binder content of geopolymer backfill materials on the compressive behavior of coal gangue geopolymer gel backfill–rock combinations (CGBRC) were systematically evaluated. Digital Image Correlation (DIC) and acoustic emission (AE) techniques were employed to reveal the strain field evolution and damage progression of CGBRC. Results show that as the content of fine coal gangue increases, the compressive strength first increases and then decreases. Compared with the compressive strength at a 20% content, the compressive strength at a 40% content increased by 33.2%, while the elastic modulus increased by 11.2%. Meanwhile, with the increase in mass concentration and binder content, the compressive strength and elastic modulus of coal gangue geopolymer filling materials show an increasing trend, reaching peak values at 86% mass concentration and 32% binder content, respectively. The strain concentration zones mainly form near the backfill interface, with propagation paths governed by backfill strength. Damage evolution undergoes three stages including rapid accumulation during compaction, gradual development in the elastic-plastic stage, and abrupt acceleration at failure. The interfacial debonding behavior is primarily influenced by the strength difference between the backfill and surrounding rock. Specimen failure is dominated by brittle shear fracture, categorized into three modes based on crack paths relative to the backfill, which include penetrating backfill failure, axisymmetric interface failure, and centrally symmetric interface failure. These findings offer theoretical and technical support for coal gangue resource utilization and green mining practices, advancing sustainable solid waste management. Full article

Zn–Al–Mg coatings are widely used because of their excellent corrosion resistance, in which α-Al dendrites play a crucial role. This study investigated the selective corrosion behavior of α-Al dendrites in a hot-dip Zn–14Al–0.5Mg coating, including the as-received state, after 20 months of indoor exposure, and under salt spray corrosion. The coating consisted of α-Al dendrites, η-Zn phase, and a small amount of eutectic Zn–Al–Mg. Minor black spots were observed on the initial surface. After indoor storage, extensive corrosion occurred in α-Al dendritic regions, while the remaining η-Zn became protruding. Corrosion propagated preferentially along the Al-rich dendritic into the coating, reaching the substrate, rather than progressing layer by layer. Electrochemical testing results indicated spatial heterogeneity in the corrosion resistance of the coating surface after long-term indoor storage. Cl⁻ could more readily penetrate into the corroded dendrites, accelerating corrosion and shifting the mode from lateral propagation to vertical penetration. The selective corrosion was attributed to dendrite segregation and surface oxide film breakdown. Controlling dendrite morphology is essential for improving coating performance. Full article

High renewable penetration introduces stochastic variability in distribution-network operation, requiring probabilistic AC power-flow tools that remain accurate in the tails while avoiding the computational burden of large Monte Carlo simulation. This paper presents a fully reproducible non-intrusive polynomial chaos expansion (PCE) framework for uncertainty propagation through nonlinear Newton–Raphson AC power flow. The method uses sparse-grid quadrature to train PCE surrogates from deterministic power-flow evaluations and is benchmarked against high-fidelity Monte Carlo simulations. In the validation, the IEEE 33-bus feeder is evaluated using up to 50,000 Monte Carlo samples, 95% bootstrap confidence intervals, PCE orders 2–5, correlated uncertainty scenarios, realistic thermal-loading recalibration, reactive-power sensitivity of renewable injections, multi-feeder testing on IEEE 33-bus, CIGRE MV, CIGRE LV, and IEEE 118-bus networks, and a 365-snapshot full-year daily screening. For the base IEEE 33-bus case, third-order PCE required only 494 deterministic power-flow evaluations and reproduced the 50,000-sample Monte Carlo benchmark with relative mean errors of 0.014% for minimum voltage, 0.119% for active losses, and 0.113% for substation import. The corresponding wall-clock speed-up was 13.29×, while reducing deterministic evaluations by approximately 101×. Correlated load–PV uncertainty increased the upper tail of substation import from 6.06 MW to 6.30 MW, and realistic thermal recalibration revealed line-loading p99 values above 100% for the 60% target case, demonstrating the operational value of physically meaningful ampacity settings. The proposed workflow provides an open, scalable, and tail-aware basis for uncertainty-informed distribution-network planning under renewable variability. Full article

Rockburst is one of the major geological hazards in the construction of deep-buried and high-geotemperature tunnels. Using triaxial compression tests and acoustic emission (AE) techniques, this paper conducts a preliminary exploratory investigation on the deformation and failure characteristics, mechanical parameters, acoustic emission responses and energy evolution laws of typical rockburst-prone rocks under confining pressures of 10–30 MPa and temperatures of 100–250 °C. The results show that within the research scope, sandstone exhibits brittle characteristics including compaction, linear elasticity, crack initiation and propagation, stable crack propagation stage, accelerated crack propagation stage, and stress drop stage. Within a certain range, peak strength and damage strength increase with the rise in confining pressure and temperature. The elastic modulus increases with rising confining pressure. The damage point may be the critical point of energy conversion and acoustic emission activity. After damage, the work done by external forces is mainly converted into dissipated energy. With the intensification of surrounding rock damage, the ratio of elastic strain energy to total energy gradually decreases, while the ratio of dissipated energy to total energy gradually increases. Acoustic emission activity increases significantly at the damage point and reaches its peak at the peak strength. The cumulative acoustic emission ring count and cumulative energy increase slowly before the peak and grow rapidly after the peak. Under thermo-mechanical action, new cracks in sandstone preferentially initiate along grain boundaries, and the inconsistent deformation between grains will promote the formation of transgranular cracks. The connection, convergence and final penetration of cracks lead to sample failure. The elevation of temperature and confining pressure can enhance the bearing capacity of sandstone, indicating that a high-temperature and high-stress environment may be conducive to the occurrence of rockbursts. The research results provide scientific support for an in-depth understanding of the mechanical behavior and instability risk of rockburst in deep-buried and high-geotemperature tunnels, and can provide a theoretical basis for rockburst prevention and control of high-geotemperature tunnels of the CZ Railway. Full article