Search Results (12,267)

The phreatic surface and seepage field are key factors causing instability in tailings storage facilities (TSFs). In this study, electrical resistivity tomography (ERT) was used to determine the internal structure and phreatic surface of the TSF of Husab Mine. The seepage pathways at the southeast and northwest corners of the TSF were identified and the seepage mechanisms were analyzed. In order to discharge the slurry, outlets equipped with valves were installed on the tailings embankment. During the deposition process, time-lapse electrical resistivity tomography (TL-ERT) was conducted to monitor the infiltration of water around the W13 outlet. The results show that the tailings sediments were divided into three layers based on resistivity values. The top layer consisted of shallow, unsaturated tailings material, while the middle layer comprised saturated tailings material. The thickness of the saturated zone gradually increased from the dam toward the decant pool. The bottom layer consisted of the geomembrane liner and natural sediments. Two seepage locations, named the Lebusa corner and Alister corner, were located at the southeast and northwest corners of the TSF, respectively. Seepage occurred because clarified water originating from the decant pool migrated through the saturated zone of the tailings pond, along the base of the tailings embankment. Upon encountering the starter dam, the water was impeded and subsequently emerged as seepage at the junction between the starter dam and the tailings embankment. TL-ERT monitoring shows that the extent of increased moisture was approximately 60 m horizontally and roughly 10 m vertically due to deposition at the W13 outlet. Full article

This paper proposes a set of trajectory generation strategies for industrial robots that use ray-casting over the workpiece CAD model for various manufacturing operations. By employing ray-casting on a triangular-mesh representation of the production part, points can be generated across the entire surface without extracting geometric features such as curves, edges, or planes. This approach enables the development of diverse point-generation methods with distinct characteristics, adaptable to the specific requirements of each part and manufacturing process. The developed algorithms achieve results comparable to existing robot programming methods, and, when integrated into the specialized offline programming environment, they enable flexible trajectory generation for operations such as sanding, milling, adhesive deposition, and painting. Finally, these trajectories are automatically exported in a syntax that ensures rapid integration of the point sequence into a base program compatible with an articulated robot controller. The results show that the proposed methods can effectively generate trajectories for sanding and milling using two different robots. Full article

Multicomponent ferrite oxides with mixed valence states and tunable oxygen-defect chemistry are promising active materials for low-power memristive synapses. In this work, Ag/Ni_0.3Cu_0.2Zn_0.5Co_0.005Mn_0.005Fe_1.99O/Ag memristors were fabricated by pulsed laser deposition, and the effects of post-deposition annealing at 700–900 °C on film structure, chemical states, magnetic behavior, resistive switching, and synaptic performance were investigated. The film annealed at 800 °C exhibited a dense surface morphology, improved crystallinity, and uniform elemental distribution. X-ray photoelectron spectroscopy confirmed the coexistence of Fe²⁺/Fe³⁺ states and oxygen-related defect components, indicating the presence of oxygen vacancies. Room-temperature magnetic hysteresis measurements revealed ferrite-type magnetic behavior in the annealed films, with the 800-annealed sample showing a relatively well-defined normalized hysteresis response. The optimized device exhibited representative bipolar resistive switching within ±0.5 V, distinguishable high- and low-resistance states, Ohmic conduction in the low-resistance state, and Schottky-emission-dominated transport in the high-resistance state. These results suggest that reversible oxygen-vacancy migration and interfacial barrier modulation govern the switching process. The device showed preliminary synaptic-like transient current responses. Further systematic reliability and conductance-modulation measurements are still required to fully evaluate endurance, reproducibility, and synaptic weight-update behavior. This study demonstrates that annealing-controlled multicomponent ferrite oxides offer a feasible route for energy-efficient memristive synaptic devices. Full article

This study statistically examines how fused deposition modeling (FDM) parameters influence the mechanical behavior of FDM-printed lattice structures. Diamond triply periodic minimal surface (D-TPMS) lattice structures were 3D-printed using carbon fiber-reinforced polylactic acid (PLA/CFs) composites. The effects of FDM parameters, including extruder temperature (ET), printing speed (PS), and layer thickness (LT), on the mechanical behavior of D-TPMS structures were investigated using response surface methodology (RSM). Uniaxial compression testing was performed to evaluate the mechanical properties of the 3D-printed samples, including compressive modulus (E), peak strength (σ_peak), and specific energy absorption (SEA). The optimal FDM parameter settings for maximizing E, σ_peak, and SEA were determined using multi-objective optimization via the desirability function. A deformation analysis was further conducted. The as-built D-TPMS samples generally matched the design relative density (44%), with absolute errors of 0.3–4.5%, while the largest deviation (~4.5% below the design value) occurred at low-ET and high-LT combinations. The results showed that LT was the dominant factor affecting E and σ_peak, accounting for 77.45% and 89.25% of the total variation, respectively, whereas ET had the most significant influence on SEA, accounting for 55.76% of its total variation. In addition, increasing ET improved interfacial bonding and shifted the failure mode from early wall and layer fracturing to predominantly wall yielding, thereby enhancing structural integrity during compression. Higher LT deteriorated the mechanical properties (E, σ_peak, and SEA) and promoted a progressive failure mode characterized by gradual interlayer separation. The findings revealed that the optimal settings (60 mm/s PS, 232 °C ET, and 0.2 mm LT) simultaneously maximized E (0.567 GPa), σ_peak (15.937 MPa), and SEA (15.510 J/g), with high predictive accuracy (maximum % error ~±1.41%). Correlation analysis further revealed significant relationships between as-built relative density and the compression responses E, σ_peak and SEA, with correlation coefficients exceeding 0.8. Overall, this study advances the understanding of how FDM printing parameters govern the mechanical behavior of PLA/CFs D-TPMS lattice structures and highlights the potential for predicting their mechanical performance. Full article

Fused deposition modelling (FDM) is increasingly used to produce high-performance polymer components; however, the mechanical performance of printed parts is often limited by weak interlayer adhesion, void formation, and residual thermal stresses. In this study, the effects of nozzle temperature, bed temperature, and post-treatment annealing temperature on the tensile and flexural strength of FDM-printed polyether ether ketone (PEEK) were investigated and optimized using Response Surface Methodology (RSM). A face-centred central composite design was employed to evaluate the individual, quadratic, and interaction effects of the three thermal parameters. The results showed that post-treatment annealing temperature was the most influential factor, contributing 56.48% to tensile strength and 52.73% to flexural strength, followed by nozzle temperature, which contributed 30.56% and 30.15%, respectively. Bed temperature showed a comparatively smaller individual effect; however, its interaction with nozzle temperature significantly influenced both tensile and flexural strength. The confirmation experiment performed at 200 °C post-treatment temperature, 414 °C nozzle temperature, and 142 °C bed temperature produced a tensile strength of 55.65 MPa and a flexural strength of 81.08 MPa, with prediction errors of 5.63% and 4.08%, respectively. SEM fracture analysis provided qualitative evidence that improved thermal processing reduced interlayer separation and visible void-related defects while promoting a more cohesive fracture morphology. These improvements are attributed to enhanced interlayer fusion, possible polymer-chain diffusion across layer boundaries, and thermal-stress relaxation during annealing. The findings demonstrate that thermal-parameter optimization and post-treatment annealing can improve the mechanical performance of FDM-printed PEEK within the investigated processing window. Full article

The interaction of biomaterial surface with cells is a pivotal factor in tissue engineering and three-dimensional (3D) modeling. This paper presents an approach to modifying polystyrene surface by plasma-enhanced chemical vapor deposition of thin plasma-polymerized hexamethyldisiloxane (pp-HMDSO) films to enhance biocompatibility and stimulate the formation of 3D cellular structures. The coatings were characterized by SEM, EDS, XPS, FTIR, AFM, contact angle measurements, and surface free energy (SFE) analysis. A hydrophobic surface initiates 3D structure formation by ensuring uniform cell repulsion and stimulating intercellular interactions. Biological evaluation was performed on U-87 MG (glioblastoma) and HMC3 (microglia) cell lines. For U-87 MG, the pp-HMDSO layer proved critical: cell death and atypical adhesion occurred on untreated plastic, whereas stable spheroids formed on the modified surface. HMC3 cells formed small spheroids even on unmodified surfaces, but on pp-HMDSO coatings, the process was more intense and the structures more uniform due to surface hydrophobicity. These results demonstrate the potential of plasma-polymerized HMDSO films as a scalable platform for creating biomaterials with controlled properties for 3D culturing. Full article

A capillary-driven microfluidic electrical screening platform was developed using silver nanoparticle (AgNP)-decorated laser-patterned villous microstructures on a glass substrate for the analysis of H3N2-infected A549 cells. The device integrated nanosecond laser patterning, AgNP conductive thin-film formation, passive capillary transport, and direct electrical readout within a single microfluidic sensing structure. Villous-like arrays were fabricated using a 1064 nm IR pulsed laser at a fluence of 4.35 J/cm², with a repetition rate of 300 kHz, pulse overlap of 96.7% and scanning speed of 500 mm/s. The fabricated structures exhibited a diameter of 60 μm, height of 80 μm and interpillar pitches ranging from 30 to 90 μm. After AgNP deposition, the surface showed a dominant Ag content of 59.2%, confirming successful formation of conductive microstructured electrodes. The 30 μm pitch structure produced the highest current response of 22 μA at 1 V and the highest ΔI_norm of 0.053 after introduction of H3N2-infected A549 samples. Wettability and capillary transport were tunable by pitch, with contact angles (CAs) decreasing from 140° to 30° and flow velocities decreasing from 0.1 mm/s to 0.03 mm/s. Formalin-fixed H3N2-infected A549 cells were electrically distinguished from non-infected A549 controls over 10¹–10⁶ PFU/μL, with detectable responses down to 10¹ PFU/μL. These results demonstrate a label-free, self-driven, and fabrication-oriented microfluidic strategy for electrical screening of virus-associated cellular samples. Full article

Edible coatings are widely studied as food-compatible formulations for reducing moisture loss, oxidation, microbial spoilage, oil uptake, and quality deterioration. Their translation from laboratory formulation to industrial use, however, depends not only on film-forming composition but also on controlled deposition, retained dose, surface coverage, drying history, defect formation, hygienic operation, and reproducible performance on heterogeneous food surfaces. An OpenAlex-supported evidence-map audit (2014–2026) was used to separate direct food-coating validation from adjacent engineering models. This review reframes edible coatings as engineered deposited interfaces and proposes a claim-controlled, evidence-tiered framework linking food-grade biopolymer fluids, processability, atomization, droplet impact, wet-film evolution, dry-film structure, image-based metrology, multiphase modeling, and food-performance endpoints. This review outlines the prerequisites for future digital-twin-ready edible coating workflows by linking functional biopolymer fluids, deposition technologies, droplet physics, intelligent image metrology, Computational Fluid Dynamics (CFD), Volume of Fluid (VOF), uncertainty reporting, food-performance endpoints, safety, Life-Cycle Assessment (LCA), Techno-Economic Analysis (TEA) and patent-aware innovation. Digital twins are treated as a future integration target that depends on validated inputs, standardized reporting, deposition metrology and food-specific model validation. The central argument is that progress in edible coatings requires fewer isolated formulation claims and stronger validated links between deposited-interface properties and food-relevant function. A minimum reporting checklist is proposed to support reproducible comparison of deposition routes, coating structures, and translation potential. Full article

The development of potash deposits under complex mining and geological conditions requires the implementation of efficient geotechnologies, including backfilling of mined-out voids. Preserving the water-protective strata and preventing mining-induced accidents are impossible without accurate prediction of the stress–strain state of the backfill mass. Traditional models, based on the Mohr–Coulomb criterion, are unable to properly describe physical and mechanical processes occurring in crushed salt rock, including the transition from dilatancy to compaction and nonlinear hardening. This requires the application of specialized models such as the SRP model. The aim of this study is to investigate the mechanical response of crushed salt rock backfill material under complex loading conditions and to calibrate the parameters of the SRP model in order to improve the accuracy of geomechanical calculations. The shape of the plastic flow surface in the deviatoric plane was established, including both shear and cap components. A nonlinear dependence of the friction angle on mean stress was identified and described by a logarithmic function. The law of plastic hardening was determined, and a non-associated plastic flow rule was confirmed in the shear domain. The calibrated SRP model allows for predicting the backfill mass behavior with high reliability, which is a necessary condition for substantiating the parameters of safe potash mining. Full article

In slurry shield tunneling, inefficient control of slurry permeability in sandy formations can cause excessive slurry loss, increased material consumption, reduced bentonite reuse, and compromised tunnel-face stability. To address these challenges and enhance material efficiency, this study investigates slurry infiltration and bentonite particle deposition mechanisms in saturated sandy soils. Based on deposited-particle mass conservation and slurry volume conservation coupled with excess pore-water pressure, a mathematical model is established to capture the evolution of slurry rheological properties and soil pore characteristics during infiltration. Through multilayer infiltration column experiments, a multiple regression formula for the filtration coefficient is established, considering the spatiotemporal variability of slurry and soil properties. Furthermore, a dynamic penetration criterion for slurry particles is proposed and verified through single-soil infiltration tests. Results demonstrate that most bentonite particles deposit on the soil surface, with only a minimal fraction migrating into deeper pores until reaching shear stress equilibrium. The maximum infiltration distance is positively correlated with soil particle size but negatively correlated with slurry mass concentration. Increasing the slurry mass concentration or shear strength promotes the development of a well-structured filter cake and infiltration zone. These findings provide a theoretical framework for precisely regulating slurry permeability, thereby minimizing material waste and supporting sustainable shield tunneling operations. Full article

Corrosion of carbon steel components represents a major economic and safety challenge in industrial applications, motivating the development of protective thin film coatings with optimized deposition parameters. This study investigates the deposition of nickel nitride (Ni-N) thin films on AISI 1016 carbon steel and silicon (111) wafers by reactive radio-frequency (r.f.) magnetron sputtering at three power levels: 150, 175, and 200 W. Surface color, film thickness, roughness, crystal structure, mechanical properties, and electrochemical behavior were evaluated using optical microscopy, stylus profilometry, atomic force microscopy (AFM), X-ray diffraction (XRD), nanoindentation, and potentiodynamic polarization combined with electrochemical impedance spectroscopy (EIS). Increasing r.f.-power produced systematic surface color changes consistent with variations in film thickness, which ranged from approximately 25.0 to 50.7 nm. Higher deposition power promoted smoother surfaces, with average roughness (Ra) decreasing from 64.28 nm at 150 W to 20.62 nm at 200 W. XRD analysis revealed a monocrystalline Ni₃N hexagonal close-packed (HCP) phase at 150 W, transitioning to a dual-phase Ni₃N (HCP) and Ni₄N face-centered cubic (FCC) microstructure at 175 and 200 W. The highest hardness (11.80 ± 3.34 GPa) was recorded at 150 W, accompanied by pop-in events attributed to dislocation nucleation in the HCP lattice. Electrochemical evaluation in 3.5 wt.% NaCl solution demonstrated that films deposited at 150 and 175 W exhibited corrosion current densities and rates exceeding those of bare steel, confirming that these conditions accelerate rather than inhibit corrosion. Only the film deposited at 200 W achieved superior corrosion protection, with a corrosion current density and rate approximately 50% lower than bare steel, attributed to its denser microstructure and smoother surface morphology. These findings demonstrate that r.f. power is a critical parameter governing the properties of Ni-N thin films, and that careful optimization of deposition conditions is essential before recommending such coatings for industrial corrosion-protective applications. Full article

A frequent and sudden two-phase (solid–liquid) geological hazard in mountainous areas, the evolution of debris flows involves the coupling of multiple physical fields, making monitoring and early warning particularly challenging. To accurately reveal the dynamic patterns of debris flow evolution and improve early-warning accuracy, this study focused on the Ni Chang Valley area in Shimian County, Ya’an City, Sichuan Province. Based on the COMSOL Multiphysics coupling simulation platform, a multiphysics bidirectionally strongly coupled numerical model was proposed and constructed, integrating the SPH (smoothed particle hydrodynamics) meshless particle method, FLO-2D shallow-water dynamics, and the MassFlow full-process simulation approach. Using COMSOL as a unified framework, this model employs MassFlow’s deep-integration, continuous medium method to simulate rainfall triggering and material source activation, FLO-2D’s shallow-water equations to describe macroscopic flow-deposition processes, and SPH’s mesh-free particle method to accurately capture large deformations and free-surface flow. The model fully reproduces the entire dynamic chain of debris flow processes, from rainfall triggering and soil mobilization to fluid transport and channel deposition. The reliability and accuracy of the model were verified by comparing it with field measurements from the 20 September 2022 historical debris flow event at Ni Chang Valley. Quantitative analysis indicates that when the viscosity coefficient increases from 0.1 Pa·s to 100 Pa·s, the flow velocity decreases by approximately 47% and the flow depth increases by approximately 62%. When the yield stress increases from 1 Pa to 100 Pa, the deposition area shrinks from 269,900 m² to approximately 109,000 m², a reduction of about 60%. Combining the results of the dynamic analysis, daily maximum temperature, daily precipitation, moisture content, mud-water level, and ground surface displacement were selected as core monitoring indicators. The analytic hierarchy process (AHP) was used to determine the weights of each indicator, and a data- and physics-driven weighted summation model for debris flow monitoring and early warning was constructed to achieve a five-level debris flow monitoring and early-warning system. Historical disaster cases demonstrate that this early-warning model can provide advance predictions of debris flow disasters up to 2 h and 40 min in advance. The warning lead time is sufficient, the grading logic is clear, and the model is capable of accurately capturing precursor information on disasters. Full article

This study examines the applicability of Plasma Transferred Arc (PTA) surface treatment as an advanced technique for the refurbishment of railway wheel treads. Conventional wheel reprofiling, typically performed on semi-automatic lathes, requires the removal of a minimum of 6 mm of material from the running surface, which accelerates rim thinning and ultimately necessitates wheel replacement. Moreover, the reprofiled surfaces are not subjected to any subsequent treatment aimed at enhancing their durability. To overcome these limitations, PTA cladding was selected due to its ability to generate surface layers with superior mechanical and tribological properties. In contrast to widely used diode laser technologies, PTA enables the deposition of alloying materials in powder form, ensuring a stable, controllable, and efficient cladding process. The resulting microstructure consists of a heat-affected zone, a transition zone, and a re-melted zone, each exhibiting significantly increased hardness relative to the untreated base material. The process facilitates the incorporation of metallic particles into the surface layer, promoting the formation of a dense, wear-resistant coating. These materials possess huge potential utility regarding the wear resistance reaching even ca 10% of the base material wear in the case of 505 PTA and over 20% in the case of the 15 E material. The findings indicate that PTA surface treatment has substantial potential to extend the operational lifespan of railway wheels by providing a highly durable and mechanically robust surface, thereby reducing maintenance frequency and the associated costs. Full article

In our day-to-day lives, we are regularly exposed to a wide spectrum of dangerous gases. Their origins vary, ranging from industrial activities to objects found within our very homes. Naturally, there is an interest in developing cost-efficient and durable devices that can successfully track these gases within our environment. One such candidate is represented by chemoresistive gas sensors based on metal oxides. This is due to their simple architecture and the possibility of scaling down their size, making them valid contenders for future advancements in portable gas sensors. This review focuses on chemoresistive gas sensors that have been obtained through different Physical Vapor Deposition (PVD) methods, which are easily scalable for potential technological transfer towards commercialization or are already exploited at the industrial level, and how varying different deposition parameters impacts the structure of the active material, thus modifying the gas sensing properties of the device. In this review, we report results obtained for different metal oxides: WO₃, ZnO, CeO₂, TiO₂, NiO, and SnO₂. The main findings of these studies revealed that the sensor’s response was highly impacted by oxygen deficiencies within the deposited material, the specific surface area, and the thickness of the film. Moreover, this study also delves into different strategies of functionalization that result in improved gas sensing properties. Thus, we herein report how tailoring functional properties modifies the gas sensing performance of different metal oxides. Full article

Bacterial biofilms represent a major clinical challenge, being responsible for the majority of chronic infections and significantly reducing the effectiveness of antibiotic therapy. Their formation on implant surfaces, particularly those made of titanium and its alloys, is strongly associated not only with antimicrobial tolerance but also with persistent, hard-to-eradicate infections, implant loosening or failure, repeated surgical interventions, prolonged hospitalization, and increased morbidity. These complications contribute substantially to the growing problem of antimicrobial resistance and impose significant economic burdens on healthcare systems. This review discusses the mechanisms of biofilm formation, factors influencing bacterial adhesion, and the clinical implications associated with implant-related infections. Special attention is given to titanium-based biomaterials, including conventional Ti–6Al–4V and next-generation alloys such as Ti–13Nb–13Zr, highlighting their advantages and limitations in the context of biocompatibility and susceptibility to biofilm formation. Various strategies for combating biofilms are presented, including physical, chemical, and biological approaches, with emphasis on surface modification techniques. Advanced methods, particularly atomic layer deposition (ALD), are identified as promising solutions for creating uniform, antibacterial coatings, including those based on tin dioxide (SnO₂). Such modifications offer potential for reducing bacterial adhesion, improving osseointegration, and enhancing long-term implant performance. Full article