Search Results (899)

Surface-assisted laser desorption/ionization mass spectrometry imaging (SALDI-MSI) using steel target coated with silver nanoparticles (AgNPs) by electrodeposition was applied for the direct visualization of metabolites in bulb tissue of Narcissus pseudonarcissus. Fresh bulb cross-sections were transferred onto an AgNP-SALDI target by a simple tissue imprint procedure and analyzed using a MALDI TOF mass spectrometer operating in positive-ion reflectron mode. Ion images were generated after total ion current normalization and metabolite annotation was performed based on accurate mass measurements, characteristic silver adduct formation, database searches and literature data. Twenty-one ion images representing seventeen putatively annotated metabolites were selected for detailed discussion. The putatively annotated compounds included primary metabolites (histidine, malic acid, succinic acid, thiamine, coenzyme A and acetyl-coenzyme A), phytohormones (indole-3-acetic acid, indole-3-butyric acid, 3-indolepropionic acid, 4-chloroindole-3-acetic acid and abscisic acid), flavonoids and characteristic Amaryllidaceae alkaloids, including galanthamine, lycoramine, crinine, assoanine, habranthine and 5,6-dihydrobicolorine. Distinct spatial distributions were observed for individual metabolites, reflecting the metabolic heterogeneity of bulb tissues. The results demonstrate that AgNPs-SALDI-MSI provides a rapid, matrix-free approach for in situ visualization of low-molecular-weight metabolites in plant tissues while preserving their spatial organization, making it a promising tool for plant metabolomics and phytochemical investigations. Full article

Corrosion of reinforcing steel remains a major cause of premature deterioration in concrete infrastructure, motivating the development of inhibitors with lower toxicity and reduced environmental impact. This review critically examines recent advances in green and bio-based corrosion inhibitors for reinforced concrete, including plant extracts, agro-industrial residues, naturally occurring organic compounds, proteins, polysaccharides, bio-based coatings, hybrid formulations, and microbial systems. The available evidence is synthesized in terms of chemical functionality, delivery route, adsorption and film-forming mechanisms, electrochemical response, compatibility with cementitious materials, and durability under chloride- and carbonation-related exposure. Many formulations provide substantial inhibition under optimized laboratory conditions through interfacial adsorption, coordination with iron species, passive-film stabilization, suppression of anodic and cathodic reactions, and restriction of aggressive-species transport. However, reported efficiencies are not directly comparable because experimental scale, exposure conditions, dosage, steel preparation, and calculation methods vary considerably. Moreover, long-term reinforced-concrete and field studies remain scarce, while extract standardization, cement compatibility, toxicity, biodegradability, and life-cycle performance are frequently insufficiently addressed. Green and bio-based inhibitors therefore represent a promising but heterogeneous technology class. Their practical implementation requires chemically reproducible formulations, complementary electrochemical and surface evidence, concrete-scale durability assessment, environmental validation, and stage-gated progression toward monitored field applications. Full article

In ultra-supercritical (USC) power plants, P92 steel welded joints are continuously subjected to creep-fatigue (CF) loading, rendering them susceptible to premature cracking during service. To investigate the CF interaction behavior, CF tests were performed on P92 steel welded joints at 650 °C under various dwell times. The results indicate that prolonged dwell periods progressively shorten the cycle life. Scanning electron microscopy (SEM) observations reveal that with increasing dwell time, the fracture mechanism of the P92 steel gradually transitions from a fatigue-dominated failure mode to one governed by creep-fatigue interaction damage. Subsequently, nanoindentation was employed to evaluate the hardness (H), elastic modulus (E), and creep deformation, based on which the strain rate sensitivity (m) was estimated and the underlying damage mechanisms were thoroughly discussed. Full article

Super duplex stainless steels are widely used in seawater desalination plants due to their high mechanical strength and excellent corrosion resistance in chloride-rich environments. However, during reverse osmosis processes, the salinity of the reject stream increases progressively, generating concentrated brines with concentrations close to 7 wt.% NaCl, which represent a chloride-rich service environment that may affect passive film stability and promote localized corrosion. This study investigates the effect of novel La Geria-inspired microstructures (LGMs) generated by laser surface texturing on the microstructure, microhardness, and electrochemical behavior of UNS S32750 super duplex stainless steel in 3.5 wt.% and 7.0 wt.% NaCl solutions, simulating seawater and concentrated desalination brine. Electrochemical results show that textured surfaces exhibit improved corrosion resistance, with more stable corrosion potentials, lower corrosion current densities, and higher impedance values. Microhardness measurements revealed a homogeneous mechanical response, confirming that laser texturing does not alter the mechanical integrity of the material. Microstructural observations showed reduced surface degradation and improved preservation of the duplex ferrite–austenite structure in textured samples after exposure to chloride solutions. These findings demonstrate that biomimetic laser surface texturing enhances corrosion resistance by modifying interfacial conditions and stabilizing the passive film, providing experimental evidence of the beneficial effect of LGMs in aggressive desalination environments. Full article

To address the problem of lacking effective evaluation benchmarks for UAV navigation algorithms in complex-structured, GNSS-denied industrial environments (e.g., fully enclosed stockyards), this paper proposes and open-sources a multi-modal UAV navigation dataset. The dataset is collected in a real steel plant enclosed stockyard, integrating LiDAR point clouds, IMU, RGB images, and high-precision total station ground truth trajectories, and specially designs ArUco markers to aid visual localization. Different from existing datasets targeting urban or campus scenes, this dataset realistically reflects the challenges of GNSS-denied signal, weak texture, high dust, and complex spatial grid structures in industrial environments. Through the evaluation of various mainstream LiDAR odometry and fusion navigation algorithms, the difficulties encountered by existing methods in this scenario are highlighted, and the potential of the proposed dataset as a valuable benchmark for developing and quantitatively testing highly robust navigation algorithms is suggested. Full article

Ultra-supercritical (USC) steam turbines combine severe steam conditions with increasingly frequent start-up, shutdown, and load-following operations. Their main steam valves must preserve pressure boundary integrity, sealing, and rapid actuation while non-uniform heating, creep, cyclic plasticity, oxidation, wear, and contact redistribution alter component geometry. However, the relevant evidence remains fragmented across alloy development, component thermo-mechanics, valve aerodynamics, and lifetime monitoring. This short, mechanism-oriented review integrates these domains through a material structure–function framework in which deformation relative to assembly clearance governs jamming risk. It synthesizes evidence on heat-resistant body and surface materials, 9–12% Cr steel stability, weldability and repair sensitivity, and cold, warm, and hot start-up histories. It also evaluates creep–fatigue interaction, contact, flow-induced vibration, multi-physics modeling, validation, uncertainty, monitoring, and digital twins. The synthesis shows that neither peak equivalent stress nor steady-state temperature alone can establish functional reliability. Credible assessment requires temperature-dependent material data, realistic steam-side heat transfer, cyclic constitutive behavior, initial and residual clearances, manufacturing and assembly tolerances, state-dependent friction, uncertainty analysis, and corroborating plant or inspection evidence. The most consequential research needs are valve-level validation datasets, thermal contact testing, function-oriented life criteria, and uncertainty-aware digital twins that jointly inform materials, geometry, and transient operation. Full article

Corrosion in carbon steel piping systems is a critical issue in hydroelectric power plants, as progressive wall thickness loss may compromise integrity and operational reliability. This study proposes a data-driven framework combining descriptive statistical analysis and distinct clustering methods to map and rank corrosion conditions in water pipeline systems of a hydroelectric power plant in Brazil. A total of 4916 pipe segments from 20 generators (generating units 1 and 2) were evaluated and the feature matrix included wall loss descriptors, measured thickness statistics, minimum allowable thickness, wall integrity indicators, pipe geometry, segment type, and system information. Descriptive analyses revealed heterogeneous corrosion patterns across generating units, segment types, diameters, and inspection points, with localized severe wall loss conditions in specific segments. A principal components analysis was applied to reduce the original feature space while preserving approximately 80% of the cumulative variance, as suggested by the literature. The best clustering solution was obtained using a weighted consensus model based on the Calinski–Harabasz index, resulting in five degradation/integrity profiles that support segment-level corrosion ranking and inspection prioritization. The proposed framework provides a structured basis for integrating inspection data, statistical descriptors, and integrity indicators into maintenance and decision support processes for hydroelectric power plant piping systems. Full article

The operational dynamics of the steel industry constitute one of the work systems with the highest severity and accident rates. To address this, this research multidimensionally evaluates and stochastically predicts the preventive capability of the safety system in a steel plant. Using a quantitative, evaluative, and longitudinal three-phase design, the retrospective evaluation of nine preventive variables was employed using Six Sigma metrics (DPMO, $Z$, $Y$), along with the evaluation of overall performance through the Geometric Capability Indicator (GCI) and the Arithmetic Capability Indicator (ACI), and the stochastic modeling of the process using Markov chains. It was demonstrated that evaluating processes in isolation hides structural inefficiencies, as four variables showed an Excellent individual performance ($Z\approx 6.0$), but the comprehensive multivariate evaluation revealed a Deficient systemic state (GCI of 0.471 and ACI of 0.493). Furthermore, Markov modeling on the compliance of the process management index predicted a 100% probability of long-term stagnation in a deficient absorbing state ($x_1=1$). It is concluded that the proposed method functions as a rational anticipation system that provides potential managerial benefits by offering early warning indicators of operational degradation, supporting corrective decision-making on unstable preventive indicators. Full article

The increasing demand for sustainable road infrastructure has encouraged the development of asphalt mixtures incorporating recycled materials and industrial by-products. This study developed and validated a highly circular AC14 asphalt surface mixture incorporating steel slag aggregates (SSA) and reclaimed asphalt pavement (RAP). The laboratory-designed mixture contained 63.8% SSA and 17.2% RAP, corresponding to 81.0% secondary materials, or 83.0% when recovered filler is included. Its volumetric and mechanical performance was compared with that of a conventional AC14 surface mixture with natural aggregates. The highly circular formulation was then produced in an asphalt plant and applied in a full-scale field trial. A life cycle assessment (LCA), following EN 15804:2012+A2:2019, and a production-stage cost analysis were conducted using plant-specific data. The highly circular mixture showed improved rutting resistance, higher stiffness modulus, very high resistance to water damage, and better fatigue indicators than the conventional reference mixture. The field trial supported its feasibility under real production and construction conditions. The LCA showed reductions in 12 of the 13 product-stage environmental impact indicators, including reductions of 18.1% in total global warming potential, 26.6% in abiotic depletion potential for fossil resources, 77.6% in abiotic depletion potential for minerals and metals, and 81.5% in water deprivation potential. The estimated production-stage unit price was 36.4% lower than that of the conventional mixture and 45.4% lower than the Portuguese market benchmark. These results demonstrate the technical, environmental, and economic potential of highly circular asphalt surface mixtures incorporating SSA and RAP. Full article

Use of fly ash (FA), a by-product of coal-fired power stations, and basic oxygen furnace slag (BOFS), a by-product of steel production plants, in construction applications in Kazakhstan is limited due to their low quality and inherent problematic properties. For example, the concern with using BOFS as an aggregate in concrete is the volume expansion caused by the formation of calcium hydroxide (Ca(OH)₂) or magnesium hydroxide (Mg(OH)₂) in the concrete matrix generated by a chemical reaction between water and free calcium oxide (f-CaO) or free magnesium oxide (f-MgO) in BOFS. This issue can be addressed through geopolymerization and CO₂ curing (mineral sequestration). Moreover, the quality of FA does not meet ASTM Class F FA criteria (coarse particle sizes and low reactivity). This study investigated the physical, mechanical, microstructural, and durability properties of geopolymer mixtures composed of low-quality FA, ground granulated blast-furnace slag (GGBFS), and BOFS aggregates under various curing conditions. Six distinct curing regimes were assessed: air, water, 6 h steam, 12 h steam, 6 h steam combined with 6 h CO₂, and 6 h steam combined with 12 h CO₂ curing. The hardened properties, durability, and microstructural characteristics of geopolymer mixtures were mainly assessed by compressive strength, dielectric constant (DC), drying shrinkage, expansion (1 M NaOH solution and water expansions), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) images. Test results show that steam curing and combined steam and CO₂ curing significantly enhanced the performance of the mixtures containing BOFS aggregates. The combined steam and CO₂ curing accelerated the mineral sequestration of f-CaO in the BOFS aggregates, increasing the 28-day compressive strength by up to 27.7% and 19.2% (reaching 37.1 MPa) compared to air- and water-cured mixtures (29.1 and 31.1 MPa, respectively). While air (20.0 and 11.7), steam (28.7 and 12.4), and combined steam and CO₂ (23.6 and 12.6) curing at 1-day and 182-day yielded lower DC, water curing (30.5 and 32.2) had higher DC. The extended steam and CO₂ curing times further enhanced compressive strength growth (39.6 MPa) by 36.6% for air-curing and 27.1% for water curing, although curing duration did not significantly affect the dielectric constant. Importantly, the expansion of the BOFS aggregate in both water and 1 M NaOH solution was minimized up to 0.04% under combined curing, mitigating the inherent volumetric instability of the BOFS. Drying shrinkage was also reduced by 0.17% under combined curing conditions. Longer steam and CO₂ curing times reduced variability in dielectric constant, drying shrinkage, and the expansion characteristics. FTIR spectroscopy, SEM image, and XRD analyses confirmed that the mixture’s geopolymerization was more noticeable during the steam and CO₂ curing regimes than during water and air curing regimes. The longer steam and CO₂ curing times promoted extended hydration and the formation of stable carbonate compounds from the BOFS f-CaO, producing a significantly denser and microstructurally stable geopolymer matrix. Full article

Alternanthera philoxeroides, an invasive alien species, spreads rapidly in river systems via vegetative propagation from stem fragments, requiring river-system-scale monitoring to understand its expansion dynamics and habitat preferences. This study used multi-temporal Sentinel-2 data to analyze spatio-temporal variations in fractional vegetation cover (FVC) within a 3.5 km river reach. FVC estimates derived from vegetation indices were validated against high-resolution aerial images, with an EVI-based model achieving the highest accuracy (RMSE = 9.2%), enabling reliable monitoring even in narrow (~24 m) channels. Time-series analysis from 2019 to 2024 revealed downstream expansion beginning in 2022. Annual maximum FVC (C_max) was used to assess relationships with removal records and bank structures, showing that removal effects were temporary and more pronounced in the first year, while steel sheet-pile banks limited vegetation growth compared to concrete revetments. These results demonstrate that Sentinel-2 data can provide an effective and accessible tool for evaluating invasive plant dynamics and management effectiveness in low-flow river systems where A. philoxeroides dominates the floating vegetation community. Full article

Decarbonizing the energy sector is central to limiting global average temperature to below 2 °C above pre-industrial levels, in line with the Paris Agreement. Hydropower plays a key role in renewable energy generation, yet environmental impacts vary depending on systems and site conditions. Small hydropower (<10 MW installed capacity) is often assumed to have lower environmental impacts, but evidence remains limited, especially in cold-climate regions. This study assesses the cradle-to-gate life cycle environmental impacts of a 9.9 MW run-of-river hydropower plant in Iceland, using life cycle assessment based on the CML-IA method. The study uses primary design and operator data and provides direct comparison with published Icelandic large hydropower life cycle assessments. The functional unit is 1 kWh of electricity generated over a 60-year lifetime. Results indicate a global warming potential of 4 g CO₂ equivalent per kWh, decreasing to 3 g CO₂ under a 100-year lifetime. Hot spot analysis shows that construction materials, particularly glass fibre reinforced plastic (GRP), concrete, and steel, dominate environmental impacts. Sensitivity analysis shows the influence of lifetime, capacity factor, and dam material. Indicative reservoir emission estimates highlight additional potential impacts even for small intake reservoirs. Overall, the studied system shows higher life cycle impacts per kWh compared to Icelandic large hydropower plants, highlighting the importance of site-specific assessment and careful interpretation of small hydropower (SHP) environmental performance. Full article

Steel-reinforced concrete (SRC) frame-bent hybrid structures are widely used in conventional island buildings of nuclear power plants because of their favorable seismic performance and economic efficiency. However, the seismic fragility of these structures has not been adequately investigated. In this study, the main turbine building of the CAP1400 nuclear power plant in Rongcheng, Shandong Province, China, was selected as the prototype. A three-bay frame-bent substructure was extracted, and a 1/7-scale model was designed for pseudo-dynamic testing to investigate the evolution of seismic damage and the failure mechanisms of the structure. Based on the experimental results, a refined numerical model was developed in OpenSees. Incremental dynamic analysis (IDA) was subsequently conducted to evaluate the seismic fragility of the SRC frame-bent main turbine building under far-field and near-fault ground motions. The results indicate that the structural stiffness progressively decreases with increasing seismic demand because of concrete cracking and cumulative damage. Damage is primarily concentrated in the short columns, beam-column joints, and column bases. The fragility response also exhibits pronounced directional dependence. Because of the lower lateral stiffness in the X direction, the structure develops larger interstory drift demands and higher probabilities of exceeding the prescribed damage states in the X direction than in the Y direction. For the selected ground-motion suites, near-fault records generally produce slightly higher exceedance probabilities than far-field records at the same peak ground acceleration (PGA), with a maximum difference of 3.68%. However, the magnitude of this difference varies with the damage state, excitation direction, and ground-motion intensity. These findings indicate that pulse-like near-fault ground motions may have a measurable but moderate effect on the seismic fragility of SRC frame-bent main turbine buildings. This study establishes an experimentally validated framework for assessing the seismic fragility of SRC frame-bent structures in nuclear power plants and identifies their vulnerable components, dominant damage mechanisms, and fragility characteristics under different types of ground-motion input. Full article

Steel components in thermal power plants are vulnerable to severe wear and wall thinning induced by the high-velocity impact of pulverized coal, which significantly compromises their service life and structural integrity. To address this issue, a TiC-reinforced AlCoCrFeNi high-entropy alloy (HEA) composite coating was fabricated via laser cladding, aiming to substantially enhance the wear resistance of these critical components. The phase composition, microstructure, microhardness and tribological behaviors of the coatings were systematically investigated by XRD, SEM, EDS and dry sliding wear tests. Results show that both coatings possess dense microstructures and reliable metallurgical bonding with the substrate. The AlCoCrFeNi coating consists of a single BCC solid solution phase, while the TiC/AlCoCrFeNi composite coating contains a BCC phase and a TiC ceramic phase without brittle intermetallic compounds. The average microhardness of the TiC/AlCoCrFeNi composite coating was measured to be 823 HV_0.3, which is 85.66% greater than that of the AlCoCrFeNi coating (443 HV_0.3). Under identical wear test conditions, the AlCoCrFeNi coating exhibits a mass loss of 31.4 mg and a volumetric wear rate of 24 × 10⁻³ mm³/min, whereas the TiC/AlCoCrFeNi composite coating exhibits a mass loss of 15.6 mg and a wear rate of 13 × 10⁻³ mm³/min, corresponding to reductions of approximately 50.32% and 45.83%, respectively. The wear mechanism of the AlCoCrFeNi coating is dominated by severe abrasive wear coupled with adhesive wear, while the addition of TiC converts the wear mechanism into mild abrasive wear and oxidative wear. The incorporation of TiC particles effectively enhances the microhardness and reduces the mass loss, thereby contributing to a marked improvement in the wear properties of the laser-clad AlCoCrFeNi coating. This research provides experimental data and theoretical support for the engineering application of TiC/AlCoCrFeNi composite coatings on wear-resistant components in thermal power units. Full article

Increased corrosivity of biodiesel toward metallic components has motivated the search for environmentally friendly corrosion inhibitors. However, studies investigating plant extracts as inhibitors in biodiesel systems remain limited, particularly for babassu biodiesel. In this work, the ethanolic extract of Myracrodruon urundeuva (“Aroeira-do-Sertão”) leaves was investigated for the first time as a green corrosion inhibitor for AISI 4340 carbon steel exposed to babassu biodiesel. Static immersion tests were conducted for 2592 h (108 days) at 45 °C, and the inhibitory performance was compared with that of the commercial antioxidant Trolox™. Corrosion behavior was evaluated by gravimetric weight loss measurements and surface morphology analysis using scanning electron microscopy. Phytochemical screening, FTIR, and ¹H NMR spectroscopy revealed the presence of phenolic compounds, flavonoids, and tannins containing hydroxyl functional groups and conjugated aromatic systems. The ¹H NMR spectrum exhibited characteristic signals in the δ 6.6–6.4 ppm region, which were attributed to aromatic protons of phenolic compounds and flavonoids, while signals between δ 5.4 and 4.9 ppm indicated vinyl and olefinic protons associated with unsaturated secondary metabolites. These findings are consistent with FTIR results, confirming the presence of hydroxyl-rich phenolic structures and conjugated systems capable of promoting adsorption onto the metal surface. The extract exhibited a corrosion inhibition efficiency of 89%, significantly higher than that obtained with Trolox™ (27.9%). SEM analysis confirmed a substantial reduction in surface degradation in the presence of the extract. These results demonstrate the strong potential of Myracrodruon urundeuva leaf extract as a sustainable corrosion inhibitor for metallic materials in biodiesel environments. Full article