In this study, a temperature fixed point based on n-tetradecane was developed. The determination results of the melting plateau were also reported. By repeatedly realizing the melting plateau of n-tetradecane, its duration was determined to exceed 100 h, with a reproducibility of 0.81 mK. The stability of the melting plateau was improved by applying overheating at the beginning of the melting process. During the stable plateau period, the temperature variation within 60 h is less than 3 mK, with a variation rate of approximately 0.08 mK h-1. By using the point of inflection method, the melting temperature of n-tetradecane was determined to be 5.8643 degrees C, with an uncertainty of 0.0068 degrees C (k = 2). This work determined the melting temperature of n-tetradecane with higher precision, the measurement uncertainty is lower than the values reported in previous studies. The phase transition properties of n-tetradecane demonstrate its potential to serve as a temperature fixed point.

As offshore oil and gas resources are extensively explored, the risers of the floating production storage and offloading (FPSO) system will confront substantial corrosion challenges. To meet the demand for corrosion protection status monitoring, this study proposes a corrosion protection monitoring system that can operate at a sea depth of 300 m. It is primarily composed of a pressure-resistant, watertight enclosure, an integrated plug-in electrode system on the Outer shell and a data collection module. The system continuously monitors the electrode potential, collecting, processing, and analyzing data to offer a direct representation of the corrosion and cathodic protection condition of the subsea riser support structure, which is crucial for guaranteeing the system’s safety.

Plastic liners for type IV hydrogen storage cylinders are susceptible to degradation under high-pressure hydrogen cycling, affecting safety and service life. This study investigates three liner materials-polyamide 6 (PA6), polyamide 11 (PA11), and high-density polyethylene (HDPE)-under hydrogen cycling (1-70 MPa, 288 K) for up to 400 cycles. Results show material-specific degradation: PA6 exhibits an 8.7% increase in hydrogen permeability and a 13.3% loss in tensile strength; HDPE shows a 24.5% permeability rise and an 11.6% strength reduction; PA11 demonstrates permeability fluctuations below 5% and only a 5.1% strength loss. All materials experience ductility reductions exceeding 20%. Microstructural damage differs: PA6 develops honeycomb-like pores and crack networks; HDPE exhibits pore aggregation and lamellar separation; PA11 shows better resistance due to its flexible molecular chains. This work establishes a framework linking hydrogen permeation, microstructural evolution, and mechanical degradation, providing critical data for liner material selection and safety assessment.

Gas-solid two-phase flow erosion can result in substantial economic losses and safety risks in the textile industry, particularly in commonly used finishing equipment such as shearing machines. This study employed Computational Fluid Dynamics (CFD) combined with the Discrete Phase Model (DPM) to investigate solid particle erosion in the suction pipe of a shearing machine. The results show that with increasing flow velocity and mass flow rate, the erosion rate of the pipe wall increased significantly. At a flow velocity of 80 m/s and a mass flow rate of 4 kg/s, the maximum erosion rate was found to be 0.024 kg/m2 s. Introducing surface microstructures (hemispherical protrusions) reduced the mean wall erosion rate by up to 4.2%, while the addition of optimized guide vanes decreased the maximum erosion rate by approximately 8.3%. The optimal guide vane configuration (n = 4, length = 300 mm, depth = 35 mm, twist = 1.2) resulted in a minimum predicted erosion rate of 0.022 kg/m2 s. This study provides valuable insights for improving the efficiency of textile machinery and reducing pollution during the production process. (c) 2026 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

This study systematically investigates the hydrogen permeation behavior of polyamide 6 (PA6) under varying humidity conditions using an integrated experimental and molecular dynamics (MD) simulation approach. Permeability, diffusion, and solubility coefficients were characterized for vacuum-dried samples and those conditioned at relative humidity levels of 35%, 45%, and 90%. Results reveal that vacuum-dried PA6 exhibits significantly higher transport coefficients, with permeability approximately 112% higher than humidified samples, while diffusion and solubility increase by 54% and 37%, respectively. Microstructural analyses reveal that moisture reduces free volume, and MD simulations show water molecules occupy free volume sites and restrict chain mobility. Under humid conditions, permeability and diffusion coefficients increase with temperature but decrease with pressure, while solubility shows no significant trend. This work establishes the first quantitative dataset on hydrogen transport in PA6 under varying humidity, providing essential insights for realistic material evaluation and advancing safety standards beyond dry-condition assessments.

The potential matrix mapping (PMM) represents a novel corrosion monitoring technology, offering high precision and sensitivity. It enables the non-invasive measurement of voltage changes on a metal structure’s surface, thereby facilitating the assessment of corrosion within the inner wall of the structure. However, there are difficulties in the analysis and inversion of pitting corrosion signals, such as the multi value nature of pitting corrosion morphology parameters and low detection accuracy. A novel mathematical model for the analysis of the mapping between pitting topographic parameters and electric field fingerprint feature signals has been developed using a neural network optimised based on a genetic algorithm. Compared with the traditional methods, the model proposed in this paper can effectively improve the computational accuracy of pitting signals in PMM detection techniques.

Abstract This study employs the computational fluid dynamics simulation method to investigate hydrogen migration and storage characteristics within deformed porous structures. It is demonstrated that the hydrogen migration and storage process in porous media would be impeded more significantly with increasing pore structure deformation degree. Specifically, compared with the undeformed porous media, the hydrogen storage capacity is reduced by 2.85%, 4.75%, and 10.85% in the media deformed by 9.8%, 17.5%, and 18.3%, respectively.

Tantalum (Ta) implants are often limited by the inherent strength–ductility trade-off and insufficient corrosion resistance in physio;ogical fluids, while conventional alloying often introduces high costs and potential biosafety risks. In this study, a gradient interstitial oxygen architecture was engineered in Ta via low-pressure oxygen diffusion to address these challenges. Interstitial oxygen dissolution contributed approximately 50% of the total weight gain, with diffusion coefficients following the Arrhenius relationship (D0 = 2.8 × 10-3 cm2/s, E = 23.6 kcal/mol). The optimized Ta700 sample exhibited an increase in tensile strength from 315 MPa to 380 MPa while retaining a substantial 18% elongation, a synergy enabled by the combination of solid-solution hardening and the back-stress enhancement induced by the interstitial oxygen gradient. Furthermore, the corrosion potential shifted from -0.36 V to -0.26 V (vs. SCE), and the charge transfer resistance increased from 1.36 to 17.8 MΩ·cm2, representing an approximately thirteenfold enhancement, primarily due to the formation of a denser passive film promoted by the interstitial oxygen. The superior fluidity and exceptional permeability of the gas phase (0.1%O2/Ar) ensure that interstitial oxygen can effectively penetrate the internal constituents of these complex architectures, providing a versatile post-processing strategy for the precise functional modification of 3D-printed biomedical components in the future.

Prestressing steel strands are vulnerable to chloride-assisted corrosion fatigue because localized pits can concentrate cyclic stress before appreciable section loss occurs. This study compared eight surface states, from bare steel to silane/polydopamine (PDA) bilayers grown for 3–24 h, using surface characterization, electrochemical testing, humid chloride aging, and corrosion-fatigue testing. Silane/PDA-12h provided the best overall response, with a thickness of 176.6 ± 15.1 nm, scratch critical load of 6.86 ± 0.88 N, initial |Z|0.01 Hz of 9.11 × 10⁵ Ω cm², and corrosion current density of 0.194 ± 0.069 µA cm⁻². After 56 humid chloride cycles, its maximum pit depth was 17.0 ± 3.7 µm versus 108.8 ± 16.9 µm for bare steel; at a 500 MPa stress range, mean fatigue life increased from 0.35 × 10⁶ to 1.44 × 10⁶ cycles. The 24 h film was thicker but less durable, showing that barrier continuity, resistance to electrolyte uptake, and adhesion are more important than maximum thickness.

With the increasing importance of green chemistry and demand for sustainable technologies, plant extract-based corrosion inhibition systems have garnered significant attention. Previous reviews summarized the performance of various plant extracts as corrosion inhibitors but lacked systematic comparison and identification of key chemical constituents. To address these shortcomings, this review first outlines the extraction process of plant extracts as corrosion inhibitors, followed by a general overviewof test methods and possible working mechanisms used to investigate their corrosion inhibition properties. Emphasis is then laid on their applications in marine and acid environments, presenting differences in corrosion inhibition efficiency and investigation of effective chemicals in various extracts. Moreover, we discuss the long-term stability of plant extracts and synergistic effects with other corrosion inhibitors, and we conclude by suggesting current shortcomings in the field to guide the design and application of novel green corrosion inhibitors in the future.

To investigate the feasibility of modulating the performance of aluminum bronze coatings by varying the Al0.3CoFeNi content, this study prepared four composite coatings composed of Al0.3CoFeNi and aluminum bronze in varying mass ratios on 45 steel using laser cladding technology. The content of Al0.3CoFeNi in the composite coatings was 0%, 2.8%, 7.0%, and 14.1%. Through microstructural characterization and performance testing of corrosion resistance and friction, it was determined that the optimal corrosion and friction resistance of the coating was observed at a 2.8% Al0.3CoFeNi content. This enhancement is attributed to the formation of a continuous and dense composite layer of CuO and Al2O3 at the 2.8% Al0.3CoFeNi content in the aluminum bronze coating, which effectively enhances resistance to corrosive environments. During the wear process, the hard Fe-rich phase of the composite coating imparts high strength, thereby improving the hardness and wear resistance of the coating.

The drilling of ultradeep oil wells brings many challenges to the downhole tubular materials, where corrosion induced by halide annulus protection fluid is one major problem. In this work, the Na2CO3/NaHCO3 buffer system is employed to mitigate the corrosion of C110 steel in NaBr annulus protection fluid at 220 °C. Weight loss tests, corrosion morphologies characterizations, and electrochemical measurements were used to investigate the inhibition effect. X-ray diffraction and X-ray photo-electron spectroscopy were employed to analyze the surface phase compositions. It is found that the Na2CO3/NaHCO3 buffer reagents effectively inhibit the corrosion of C110 steel, and the inhibition efficiency can reach 96.1%. The higher pH leads to the better inhibition performance, and, particularly, the buffer system is more effective in the corrosion environment of greater aggressivity. Without buffer reagents, the steel substrate is subjected to higher degree of uniform etching and pitting corrosion due to the formation of loose and porous corrosion products. In contrast, the addition of buffer reagents facilitates the formation of thinner but denser and more protective Fe3O4 passive film, contributing the high corrosion inhibition efficiency. Our work paves the way for the safe service of NaBr annulus protection fluid at 220 °C in ultradeep oil wells.

Effects of temperature and acetic acid (HAc) on corrosion behavior of steel X80 were investigated through electrochemical measurements, including electrochemical impedance spectroscopy and potentiodynamic polarization curves. Results show that corrosion current density of steel X80 increased with temperature. Near-surface pH values of steel X80 reveal that due to the formation conditions of the corrosion film, there were differences between the electrochemical and mass loss results. Changes in cathodic and anodic charge transfer resistance indicate that the mechanism for HAc effects on cathodic reaction was buffering, and HAc served as source of H+.

The presence of welding reinforcement height (WRH) within oil and gas pipelines can lead to drastic fluid changes in localized areas during transportation, resulting in corrosion failure. In this study, the localized corrosion behavior of X80 pipeline steel welded joints with different WRH radii was investigated under various flow velocities using a high-shear erosion system. This study explores the erosion-corrosion behavior at the WRH using wire beam microelectrode (WBE) and classical electrochemical testing techniques (such as open-circuit potential (OCP) and electrochemical impedance spectroscopy (EIS)). Combined with computational fluid dynamics (CFD), the corrosion mechanisms of different regions of WRH were systematically investigated under flow conditions. The impacts of flow velocity and the radius of WRH on corrosion were analyzed. The results indicate significant corrosion variations in welded joints under flowing erosion conditions. The top of the WRH is greatly influenced by local turbulence and shear forces, exhibiting relatively lower corrosion potential and smaller charge transfer resistance, making it behave as the anode compared to adjacent positions. As the radius of WRH increases, the corrosion rate also increases. Additionally, the corrosion rate increases similarly with an increase in flow velocity.

Thermophilic microorganisms offer a favorable solution to accelerate thermophilic composting; however, the details of the microbial community responsible for compost production have only emerged recently. In this study, we reported a detailed study of fungal succession during thermophilic composting and identified key thermophilic fungi capable of enhancing the biological process of compost humification. Through high-throughput sequencing, a total of 238 fungal species were identified with beta-diversity of the fungal community significantly changing during the thermophilic phase and then maintained a relatively stable composition. The Class of Eurotiomycetes played an important role in the Thermophilic and Maturation process and became the center of fungal community network. Functional prediction revealed that fungal groups with cellulose/xylandegrading activities were significantly more abundant during the thermophilic phase compared to the initial stage. Subsequently, a total of 16 fungi were isolated in situ, and their phylogeny and degradation capabilities were determined. Two fungal strains were reintroduced into the compost, resulting in a shortened composting time from 5 days to 3 days, an improved germination index, and enhanced compost quality, particularly promoting wheat growth. The findings of this study contribute to the development of fungal inocula for accelerating composting and providing new strategies for the efficient utilization of agricultural waste. This research holds significant importance for the increasing utilization of agricultural waste.

Smart corrosion inhibitor systems have been a hot research topic in recent years. Compared with conventional corrosion inhibitors or coatings, corrosion inhibitors can be released according to specific tasks to achieve more precise corrosion protection for metals. Such smart inhibitor systems are generally based on environmental stimuli such as pH, light, ions, etc., which save the cost of corrosion inhibitors and additives, and therefore improve the effectiveness of corrosion inhibition applications. Herein, the research progress on smart corrosion inhibitors in the past decade will be summarized, including the design, synthesis, smart release, and applications of different smart inhibitor systems.

The presence of welding reinforcement height (WRH) within oil and gas pipelines can lead to micro-turbulence in localized areas during transportation, resulting in corrosion failure. This study employed a modular reconstruction method to simulate and reconstruct X80 steel welded joints, and investigated the erosion-corrosion behavior at the WRH using wire beam microelectrode, electrochemical impedance spectroscopy, and computational fluid dynamics simulations. The results show that the galvanic current density (GCD) in the weld metal exhibits cathodic behavior, while the GCD in the base metal and heat-affected zone shows anodic behavior. The top of WRH is susceptible to corrosion failure. As the radius of WRH increases, the corrosion rate also increases. Additionally, the corrosion rate increases similarly with an increase in flow velocity. The galvanic corrosion intensity factor (g) is 0.24, and the local corrosion is moderate. This work has scientific significance in ensuring the long-term safe operation of pipelines and reducing the risk of corrosion failure.

Owing to the good mechanical support, degradability, and biocompatibility, magnesium (Mg) alloys have large potential in medical applications such as guided bone regeneration membranes. However, the rapid degradation of Mg alloys under physiological conditions hinders many clinical applications. Herein, strontium-zinc-based phosphate (SZP) coatings are fabricated in situ on the zinc (Zn)-electrodeposited WE43 Mg alloy for corrosion protection, degradation control, and cytocompatibility enhancement. The Zn coating acts as a protective cathode for the Mg alloy substrate and provides a stable environment to foster the growth of the SZP coating in comparison with direct deposition onto the Mg alloy surface. The virtues are verified by the smaller corrosion current density, corrosion of the Zn coating instead of the Mg alloy substrate after soaking in artificial saliva, as well as good adhesion provided by the Zn-incorporated transition layer of SrZn2(PO4)2 between the Zn coating and SZP coating. The dense and inert SZP coating mitigates degradation as shown by a decrease in the corrosion current density of 44 times to 0.21 uA cm−2 in the simulated oral environment with artificial saliva. Furthermore, the coating resistance and charge transfer resistance increase by more than one order of magnitude compared to the Zn-treated Mg alloy, and there is no obvious degradation after immersion for 7 days. The Zn coating shows adverse effects on the attachment, spreading, and proliferation of MC3T33-E1 pre-osteoblasts, but the SZP coating providing a higher level larger than 100% of the cell viability after incubation with its extract for 3 days is more compatible with cells because of the retarded dissolution and bio-friendly chemical compositions of SrHPO4 and SrZn2(PO4)2. The hybrid coating has excellent prospects in biomedical products such as biodegradable Mg-based guided bone regeneration membranes.

PurposeThe purpose of this study is to characterize the galvanic corrosion behavior of a simulated X80 pipeline steel welded joint (PSWJ) reconstructed by the wire beam electrode (WBE) and numerical simulation methods.Design/methodology/approachThe galvanic corrosion of an X80 PSWJ was studied using WBE and numerical simulation methods. The microstructures of the coarse-grained heat affected zone, fine-grained heat affected zone and intercritical heat affected zone were simulated in X80 pipeline steel via Gleeble thermomechanical simulation processing.FindingsComparing the corrosion current density of coupled and isolated weld metal (WM), base metal (BM) and heat-affected zone (HAZ), the coupled WM exhibited a higher corrosion current density than isolated WM; the coupled BM and HAZ exhibited lower corrosion current densities than isolated BM and HAZ. The results exhibited that the maximum anodic galvanic current fitted the Gumbel distribution. Moreover, the numerical simulation results agreed well with the experimental data.Originality/valueThis study provides insight into corrosion evaluation of heterogeneous welded joints by a combination of experiment and simulation. The method of reconstruction of the welded joint has been proven to be a feasible approach for studying the corrosion behavior of the X80 PSWJ with high spatial resolution.