Search Results (18,533)

It has been demonstrated that a monomolecular surface film with semiconducting characteristics forms on an austenitic, corrosion- and heat-resistant chromium–nickel steel with 0.10 wt.% C, 20 wt.% Cr, 9 wt.% Ni, and 6 wt.% Mn (10Kh20N9G6), microalloyed with yttrium, in aqueous 1 M H₂SO₄. This passive layer exhibits semiconducting behavior, as confirmed by electrochemical impedance and capacitance measurements. For the first time, key electronic parameters, including the flat-band potential, the thickness of the semiconductor layer, and the Fermi energy, have been determined from experimental Mott–Schottky plots obtained for the interphase boundary between the yttrium-microalloyed austenitic Cr–Ni steel (10Kh20N9G6) and aqueous 1 M H₂SO₄. The results reveal a systematic shift in the flat-band potential toward more negative values with increasing yttrium content in the alloy, indicating a modification of the electronic structure of the passive film. Simultaneously, a decrease in the Fermi energy is observed, suggesting an increase in the work function of the metal surface due to the presence of yttrium. These findings contribute to a deeper understanding of passivation mechanisms in yttrium-containing stainless steels. The formation of a semiconducting passive film is essential for enhancing the electrochemical stability of stainless steels, and the role of rare-earth microalloying elements, such as yttrium, in this process is of both fundamental and practical interest. Full article

Pure titanium (Ti) and its alloys are the gold standard for dental implants because a stable titanium dioxide passive film provides excellent corrosion resistance in physiological environments. In this study, we aimed to examine electrochemical interactions between Ti and cobalt–chromium–molybdenum alloy (CoCrMo), and between a novel Ti–magnesium composite (BIACOM TiMg) and CoCrMo, when immersed in everyday solutions representing beverage or oral hygiene exposure. Test solutions included Coca-Cola^®, lemon juice, Elmex^® fluoride gel, Listerine^® Cool Mint, and Sensodyne^® fluoride paste. Immersion experiments paired Ti sticks with CoCrMo sticks and, separately, BIACOM TiMg with CoCrMo sticks, with three measurements per configuration. When galvanically coupled with CoCrMo, immersion in Coca-Cola produced galvanic potential differences of ~983 mV for the BIACOM TiMg-CoCrMo couple and 830 mV for the commercially pure grade 4 (CP4) Ti-CoCrMo couple, indicating significant electrochemical instability. Both materials showed significant potential increases in Elmex fluoride gel. Listerine Cool Mint and Sensodyne fluoride exposure produced electrochemical interactions exceeding 200 mV. Significant differences in corrosion stability were observed between CP4 Ti and BIACOM TiMg. These findings indicate that material pairing and electrolyte environment significantly influence galvanic behavior, with the Ti-Mg composite showing greater susceptibility than CP4 Ti, informing dental/biomedical material selection in oral environments. Full article

This study aims to investigate the tip resistance mechanism of open-ended steel pipe piles under partially plugged conditions by decomposing the load-sharing contribution of the ring zone and the internal soil core. A virtual static loading test was performed using the two-dimensional discrete element method (2D-DEM). Note that the findings of this study were obtained within the range of the 2D-DEM analysis conditions and do not intend to directly reproduce the three-dimensional arching mechanism or to establish equivalence between 2D and 3D responses. Quasi-static conditions were ensured by identifying loading parameters such that the energy residual remained ≤5% during driving, rest, and static loading phases, and the sensitivity criterion |Δq_b|/q_b ≤ 3% was satisfied when the loading rate was halved or doubled. The primary evaluation range of static loading was set to s/D = 0.1 (10% D), corresponding to the displacement criterion for confirming the tip resistance in the Japanese design specifications for highway bridges. For reference, the post-peak mechanism was additionally tracked up to s/D = 0.2 (20% D). Within a fixed evaluation window located immediately beneath the pile tip, high-contact-force (HCF) points were binarized using the threshold τ = μ + σ, and their occupancy ratio φ and normalized force intensity I* were calculated separately for the ring and core regions. A density-based contribution index (“K_{-density share}”) was defined by combining “strength × area” and normalizing by the geometric width. The results suggest that, for the sand conditions and particle-scale ratios examined (D/d_50 = 25–100), the ring zone tends to carry on the order of 85–90% of the tip resistance within the observed cases up to the ultimate state. Even at high plugging ratios (CRs), the internal soil core gradually increases its occupancy and intensity with settlement; however, high-contact-force struts beneath the ring remain active, and it is suggested that the ring-dominant load-transfer mechanism is generally preserved. In the post-peak plastic regime, the K_{-density share} remains around 60%, indicating that the internal core plays a secondary, confining role rather than becoming dominant. These findings suggest that the conventional plug/unplug classification based on PLR can be supplemented by a combined use of plugging ratio CR (a kinematic indicator) and the ring contribution index (K_{-density share}), potentially enabling a continuous interpretation of plugged and unplugged behaviors and contributing to the establishment of a design backbone for tip resistance evaluation. Calibration of design coefficients, scale regression, and mapping to practical indices such as N-values will be addressed in part II of this study. (Note: “Contribution” in this study refers to the HCF-based density contribution index K_{-density share}, not the reaction–force ratio.) Full article

Background: The introduction of tyrosine kinase inhibitors has revolutionised the treatment of gastrointestinal stromal tumours (GISTs), yet the role of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) in peritoneal GISTosis remains controversial. Methods: A retrospective analysis was conducted on patients with peritoneal GISTosis who underwent CRS plus HIPEC in an 18-year period. We analysed the clinicopathological characteristics and evaluated the perioperative and long-term outcomes based on the extent of disease (peritoneal cancer index, PCI), the resection (completeness of cytoreduction score) and the IM-administration. The survival factors were also analysed and the Kaplan–Meier estimator to model and estimate overall (OS) and progression-free survival (PFS). The median follow-up period was 72 months (range, 12–146). Results: A total of 25 patients (M:F = 15:10) with a median age of 57 years (range, 32–69) underwent CRS with HIPEC for peritoneal GIST metastases, detected either synchronously (n = 11) or metachronously (n = 14). The media PCI score was 9 (range, 4–20) and complete cytoreduction was achieved in 80%. Grade III complications were observed in two patients, whereas there was no postoperative mortality. Neoadjuvant imatinib-mesylate (IM) therapy was administered in 60% of patients who detected with metachronous metastases (n = 8/14), whereas adjuvant IM therapy was administered in 19 of 25 patients. Median OS was 62 months (95% CI = 22.8–101.2). Median OS and DFS for patients with PCI scores ≤ 10 were significantly longer compared to those with PCI scores > 10 (p = 0.009 and p = 0.024, respectively). Patients with CC scores of 0–1 had a significantly longer OS compared to those with CC scores of 2 (p = 0.005) and 3 (p = 0.002) and longer PFS compared to those with CC scores of 3 (p = 0.005). The need for imatinib did not significantly impact OS (p = 0.240) or PFS (p = 0.243). Conclusions: CRS combined with HIPEC shows promising results in peritoneal GISTosis, especially in patients with lower PCI and CC scores. Until larger studies validate its safety and efficacy, it should be primarily performed in expert hands in specialised peritoneal surface oncology centres. Full article

Through the mechanical analysis of AlCoCrFeNi thin-walled high-entropy alloy materials fabricated by plasma arc additive manufacturing, this study examines the practical application prospects of plasma arc manufacturing technology for thin-walled high-entropy alloys and explores its future development directions. Using a plasma arc oscillation process, a 50-layer fine additive experiment was conducted on AlCoCrFeNi high-entropy alloy materials employing both reciprocating and layer-by-layer accumulation methods. The samples were analyzed for overall appearance, microstructure, hardness, and tensile properties. The results indicate that the proportions of columnar and intergranular dendrites in the thin-walled high-entropy alloy specimens are similar, and the columnar dendrites exhibit a uniformly sized cross shape. The variation in Vickers microhardness along the horizontal direction shows lower strength at the edge positions, gradually increasing with horizontal distance. A comparison of the alloy’s transverse and longitudinal tensile specimens revealed that samples parallel to the deposition direction exhibit more regular structural arrangements, while specimens perpendicular to the deposition direction show unavoidable stress concentration at the deposition sites during tensile testing. With the increase in the height of the longitudinal specimens, the FCC structures in the alloy are significantly refined, the organizational arrangement becomes more regular, and the elongation increases. This study elucidates the plasma arc preparation technique for thin-walled high-entropy alloy materials, which is expected to achieve precise control over material composition, accurate observation of grain refinement, and uniform distribution of Vickers hardness, thereby enhancing the mechanical properties and thermal stability of the materials, with promising applications in aerospace, energy, and industrial fields. Full article

Cool roof and green roof have been acknowledged as effective heat mitigation strategies for fighting against the urban heat island (UHI). However, empirical data in hot–humid climate are still insufficient. Experimental conventional, cool and green roofs (three types) were established to comprehensively investigate the thermal performances in Hong Kong under typical summer conditions, as retrofitting strategies for an office building. The holistic vertical thermal behavior was investigated. The comparative cooling potentials were assessed. The results reveal a “vertical thermal sequence” in peak temperatures of each substrate layer for the conventional, cool and green roofs on a sunny day. However, local reversion in the thermal sequence may occur on a rainy day. Green roof-plot C (GR_C) demonstrates the highest thermal damping effect, followed by plot B (GR_B), A (GR_A) and the cool roof (CR) in summer. On a sunny day, the thermal dampening effectiveness of the substrates in the three green roofs is consistent: drainage > soil > water reservoir > root barrier. The holistic vertical thermal profiling was constructed in a high-rise office context in Hong Kong. The diurnal temperature profiles indicate all roof systems could effectively attenuate the temperature fluctuations. The daily maximum surface temperature reduction (SDMR) was introduced for cooling potential characterization of the cool roof and green roofs with multiple vegetation types. On a sunny day, the cool roof and green roofs all showed significant cooling potential. SDMR on the concrete tile of the best performing system was GR_C (26 °C), followed by GR_B (22.4 °C), GR_A (20.7 °C) and CR (13.3 °C), respectively. The SDMR on the ceiling ranked as GR_C, GR_B, GR_A and CR, with 2.9 °C, 2.4 °C, 2.1 °C and 2.1 °C, separately. On a rainy day, the cooling effect was still present but greatly diminished. A critical insight of a “warming effect at the ceiling” of the green roof was revealed. This research offers critical insights for unlocking rooftop cooling potential, endorsing cool roof and green roof as pivotal solutions for sustainable urban environments. Full article

Red mud (RM), an industrial byproduct generated during bauxite refining, has accumulated to more than 5 billion tons worldwide, posing serious environmental challenges. In response, substantial research over recent decades has focused on the sustainable utilization of RM, particularly in the field of construction materials. This review first summarizes the generation process and chemical composition of RM, and then systematically examines its potential applications in the production of artificial aggregates, partial replacement of cementitious materials, and synthesis of geopolymers. Existing studies demonstrate that RM exhibits considerable potential in construction applications: when used as an aggregate, it can reduce concrete porosity, enhance compressive strength, and improve overall mechanical performance. Moreover, RM can partially substitute cement or serve as a geopolymer precursor, contributing to the immobilization of toxic elements such as Pb and Cr while simultaneously improving the mechanical properties of both cementitious systems and geopolymers. The reactivity and performance of RM-based materials can be further enhanced through carbonation curing and other modification techniques. Finally, this review highlights the significant sustainability and economic benefits of RM-based concrete, supported by life-cycle assessment and cost–benefit analyses. Full article

Accurate day-ahead photovoltaic (PV) power forecasting is essential for secure operation and scheduling in power systems with high PV penetration, yet its performance is often constrained by the coarse spatial resolution of operational numerical weather prediction (NWP) products at the plant scale. To address this issue, this paper proposes an attention-enhanced CNN–LSTM forecasting framework integrated with a spatial downscaling strategy. First, seasonal and diurnal characteristics of PV generation are analyzed based on theoretical irradiance and historical power measurements. A CNN–LSTM network with a channel-wise attention mechanism is then employed to capture temporal dependencies, while a composite loss function is adopted to improve robustness. We fuse multi-source meteorological variables from NWP outputs with an attention-based module. We also introduce a multi-site XGBoost downscaling model. This model refines plant-level meteorological inputs. We evaluate the framework on multi-site PV data from representative seasons. The results show lower RMSE and higher correlation than the benchmark models. The gains are larger in medium power ranges. These findings suggest that spatially refined NWP inputs improve day-ahead PV forecasting. They also show that attention-enhanced deep learning makes the forecasts more reliable. Quantitatively, the downscaled meteorological variables consistently achieve lower normalized MAE and normalized RMSE than the raw NWP fields, with irradiance-related errors reduced by about 40% to 55%. For day-ahead PV forecasting, using downscaled NWP inputs reduces RMSE from 0.0328 to 0.0184 and MAE from 0.0194 to 0.0112, while increasing the Pearson correlation to 0.995 and the CR to 98.1%. Full article

Trace elements are essential for organisms, and their involvement in diverse diseases is increasingly recognised. Interest is increasing in veterinary medicine, particularly in relation to canine diseases. However, reference intervals for trace elements in dogs remain scarce. Plasma samples from 140 dogs were analysed by inductively coupled plasma mass spectrometry to determine the levels of 13 trace elements. Reference intervals (µg/L) were established for the following 12 elements: As, 0.417–8.17; Co, 0.039–1.33; Cr, 2.41–13.3; Cu, 296–790; Fe, 846–3643; Hg, 0.235–2.33; Ni, 0.567–9.04; Mn, 1.90–7.28; Mo, 1.43–12.7; Pb, 0.285–2.82; Se, 200–434; and Zn, 415–1095. However, Cd was below the limit of quantification in 77% of the samples. No differences in trace element concentrations were observed in relation to breed or reproductive status. Statistically significant differences were found in relation to sex (Cu, Mo, Zn), age (Co, Cu, Mo, Mn, Se, Zn), and size (Cu, Mo, Se, Zn); however, the magnitude of these effects varied among elements and was generally weak. Nevertheless, these factors should be considered when assessing trace element status. These reference intervals constitute an important resource for both clinical evaluation and future research. Full article

In this study, a high-performance MoS₂-based strain-gauge pressure was sensor fabricated entirely below 80 °C, enabling direct integration onto flexible polyethylene terephthalate (PET) substrates. The sensor comprised a three-layer MoS₂ channel (~2 nm) patterned via dry transfer and O₂/Ar plasma etching, interfaced with Cr/Au electrodes. This wafer-scale and cost-effective fabrication route preserves the crystallinity of the film and prevents substrate degradation. The sensor achieved a gauge factor of ~104 under compression, representing a fifty-fold improvement over conventional metal foil gauges (~2), with a linear response across both compressive and tensile regimes. Mechanical robustness was confirmed through repeated bending and tape adhesion tests, with no degradation in electrical performance. When configured as a Wheatstone bridge, this device exhibits normalized sensitivity suitable for real-time monitoring, with response and recovery times below 200 ms. These results establish O₂/Ar-plasma-patterned MoS₂ architectures as a scalable, cost-effective platform for next-generation flexible sensors, outperforming metal-foil technology in applications including seat-occupancy detection, wearable physiological monitoring, and tactile interfaces for soft robotics. Full article

This study evaluates the non-carcinogenic risk associated with chemical elements in drinking water in Jequié, Brazil, where mining activities occur. However, intensive mineral exploration, especially of metals such as vanadium (V), manganese (Mn), nickel (Ni), and chromium (Cr), has raised concerns about potential contamination. Water samples were collected for this research, and chemical analyses were conducted to quantify inorganic contaminants. Arsenic, cadmium, chromium, copper, mercury, manganese, nickel, lead, uranium, vanadium, and zinc were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The following maximum concentrations (μg L⁻¹) were obtained: As (0.36), Cd (0.76), Cr (5.5), Cu (10.6), Hg (1.7), Mn (1.3), Ni (6.7), Pb (10.1), U (0.22), V (1.9), and Zn (175). Non-carcinogenic and carcinogenic risks, such as Estimated Weekly Intake (EWI), Target Hazard Quotient (THQ), and Cancer Risk (CR), were evaluated. In one of the 30 samples analyzed, the Pb concentration exceeded the regulatory limits established by Brazilian legislation. The results highlight the importance of continuous monitoring and effective management of water quality in areas impacted by mining to protect local community health and ensure the sustainable use of water resources. The study concludes that, in general, no non-carcinogenic risks were identified for adults or children. Full article

Fiber laser surface texturing was applied to AA1050 aluminum to improve friction and wear performance of PTFE coatings. A Taguchi L16 design varied texture geometry (square, diamond, hexagon, circle), scanned area ratio (20% to 80%), and laser power (40 to 100 W) prior to primer plus PTFE topcoat deposition (25 to 35 µm). Dry reciprocating sliding against a 6 mm 100Cr6 ball was conducted at 20 N, 1 Hz, and 50 m, and wear track geometry was measured by non-contact profilometry. The non-textured reference exhibited an average COF of 0.143, whereas the lowest mean COF was achieved with diamond 60% and 40 W (0.095) and the highest with hexagon 60% and 100 W (0.156); hexagon 20% and 60 W matched the reference. ANOVA indicated scanned area ratio as the dominant contributor to COF (39.72%), followed by geometry (35.07%) and power (25.21%). Profilometry confirmed reduced coating penetration for optimized textures: the reference wear track was approximately 1240 µm wide and 82 µm deep, compared with 930 µm and 34 µm for square 80% and 40 W, 997 µm and 39 µm for diamond 60% and 40 W, and 965 µm and 36 µm for hexagon 40% and 40 W. Full article

Due to the unpredictability of seismic and the complexity of collection environments, significant uncertainty exists regarding their impact on cultural relics. Moreover, existing research on the causal analysis of seismic damage to cultural relics remains insufficient, thereby limiting advancements in risk assessment and protective measures. To address this issue, this paper proposes a seismic damage risk assessment method for cultural relics in collections, integrating deep learning and reinforcement strategies. The proposed method enhances the dataset on seismic impacts on cultural relics by developing an integrated deep learning-based data correction model. Furthermore, it incorporates a graph attention mechanism to precisely quantify the influence of various attribute factors on cultural relic damage. Additionally, by combining reinforcement learning with the Deep Deterministic Policy Gradient (DDPG) strategy, this method refines seismic risk assessments and formulates more targeted preventive protection measures for cultural relics in collections. This study evaluates the proposed method using three public datasets in comparison with the self-constructed Seismic Damage Dataset of Cultural Relics (CR-SDD). Experiments are conducted to assess and analyze the predictive performance of various models. Experimental results demonstrate that the proposed method achieves an accuracy of 81.21% in assessing seismic damage to cultural relics in collections. This research provides a scientific foundation and practical guidance for the protection of cultural relics, offering strong support for preventive conservation efforts in seismic risk mitigation. Full article

A TiAlCrSiNbY coating was fabricated on γ-TiAl alloy by arc ion plating. The coating exhibits a dense, crack-free microstructure with a thickness of 5 ± 0.5 μm and strong interfacial bonding with the substrate. The characteristic power law correlations between mass gain and oxidation time were obtained for the uncoated and the coated samples at 850 °C with rate exponents of 2.38 and 2.14, respectively. After oxidation at 850 °C for 200 h, a continuous and dense oxide layer primarily composed of α-Al₂O₃ with a low oxidation reaction rate was formed, and the mass gain of the coated sample was 1/9 times that of the uncoated sample. Additionally, the addition of Cr and Nb in the TiAlCrSiNbY coating can increase the activity of Al and promoted the formation of stable and dense Al₂O₃ oxide films, the presence of a strong high-temperature stability Ti₅Si₃ phase inhibited the affinity of Ti and O, which maintained structural integrity and enhanced high-temperature oxidation resistance. Full article

8Cr4Mo4V bearing steel is a critical material for main shaft bearings in aero-engine applications. However, the current understanding of the micro-mechanical properties of its matrix and primary carbide phases (vanadium-rich and molybdenum-rich carbides) remains insufficient. This knowledge gap readily induces various forms of deformation damage during grinding, severely compromising the surface integrity of the workpiece. To address this, nanoindentation and nano-scratch techniques were employed to systematically quantify the micro-mechanical properties of each phase and investigate the deformation damage behavior of the steel under load. Results showed that MC carbides exhibited the highest elastic modulus and microhardness, which made them more susceptible to becoming crack initiation sites during grinding. Nano-scratch testing further revealed that crack initiation at carbide edges and localized spalling were the primary damage mechanisms. This study provides a micro-mechanical foundation for controlling the grinding surface quality of 8Cr4Mo4V bearing steel, holding significant implications for optimizing grinding processes, suppressing crack initiation, and elucidating the grinding damage mechanism. Full article