Search Results (229)

Marine ports located in regions of moderate seismicity can face high Natech (natural hazard-triggered technological) risk because large inventories of hazardous materials are stored near dense urban populations. This study proposes and applies a Natech risk framework to a representative port on the Saint-Laurence River in Quebec, Canada. Site-specific peak ground accelerations (PGA) are first estimated for 12 earthquake scenarios using regional ground motion prediction equations adjusted for local site conditions. These hazard levels are combined with a damage probability matrix to estimate Hazardous Release Likelihood Index (HRLi) scores for atmospheric steel storage tanks. Offsite consequences are then evaluated to obtain Maximum Distances of Effect (MDEs) for different types of hazardous materials. MDE footprints are intersected with block-level demographic data and complemented by a domino-effect based on inter-tank spacing, yielding a tank-level Natech Risk Index $NR{\mathrm{I}}_{\mathrm{i},\mathrm{s}}$ for each storage tank ($\mathrm{i}$) and seismic scenario ($\mathrm{s}$). These values are then averaged over all tanks to obtain a scenario-level mean Natech Risk Index ($\overline{NRI}$) for each tank substance. Regression equations relating $\overline{NRI}$ to PGA are provided as a practical tool for defining critical intensity thresholds for seismic Natech risk management in marine ports. Full article

To improve the accuracy of gravimetric liquid hydrogen flow standard devices, the self-weight of the weighing tank must be minimized, because the total mass of the liquid hydrogen contained in the tank is far smaller than the structural mass of the tank itself, which severely compromises the sensitivity of gravimetric measurement. In this study, a three-dimensional finite element model of a vacuum-insulated liquid-hydrogen weighing tank was developed in ABAQUS. The inner and outer shells were modeled with 06Cr19Ni10 (304) and 06Cr17Ni12Mo2 (316) austenitic stainless steels, and Polyamide 6 (PA6) was used for the internal support. Three operating stages were considered: evacuation of the annulus (interlayer pressure reduced from 0.1 MPa to 0 MPa), pre-cooling to −253 °C, and pressurization of the inner tank (internal pressure increased from 0.1 MPa to 1 MPa). The equivalent stress and deformation were compared for different materials and wall thicknesses to evaluate structural safety and weight-reduction potential. The proposed configuration (inner shell 1.6 mm and outer shell 1.0 mm) achieves a mass reduction of more than 50% relative to the 3 mm minimum wall thickness commonly adopted for cryogenic vessels, while keeping stresses below the allowable limits. This reduction enables the use of higher-resolution load cells and thereby lowering the measurement uncertainty of the liquid hydrogen flow standard device and providing technical support for lightweight and cost-effective design, with potential applicability to other cryogenic tank systems. Full article

This study explores the viability of ultra-high-performance concrete (UHPC) as a structural material for compressed air storage (CAES) systems, combining comprehensive experimental testing and numerical simulations. Scaled (1:20) CAES tanks were designed and tested experimentally under controlled pressure conditions up to 4 MPa (580 psi), employing strain gauges to measure strains in steel cylinders both with and without UHPC confinement. Finite element models (FEMs) developed using ANSYS Workbench 2024 simulated experimental conditions, enabling detailed analysis of strain distribution and structural behavior. Experimental and numerical results agreed closely, with hoop strain relative errors between 0.9% (UHPC-confined) and 1.9% (unconfined), confirming the numerical model’s accuracy. Additionally, the study investigated the role of a rubber interface layer integrated between the steel and UHPC, revealing its effectiveness in mitigating localized stress concentrations and enhancing strain distribution. Failure analyses conducted using the von Mises criterion for steel and the Drucker–Prager criterion for UHPC confirmed adequate safety factors, validating the structural integrity under anticipated operational pressures. Principal stresses from numerical analyses were scaled to real-world operational pressures. These thorough results highlight that incorporating rubber enhances the system’s structural performance. Full article

Pile foundations are widely used to transfer axial loads to deeper strata, where uplift resistance is critical for offshore structures, towers, and retaining systems. Uplift capacity is governed primarily by shaft resistance mobilized along the pile–soil interface, yet its behavior in sand remains inadequately defined. This study investigates the shaft resistance of vertical model piles subjected to pure pullout loading in dry sand, using instrumented steel piles in a rigid steel tank with reaction beams and earth pressure sensors to capture lateral stress distribution. The effects of pile diameter D, embedment ratio L/D, and sand relative density D_r on uplift performance were systematically examined. The results show that higher relative density produces higher earth pressure coefficients K_s and, accordingly, higher uplift capacity. An analytical model was developed to predict the earth pressure coefficient K_s and shaft resistance, introducing a friction-based critical depth ratio linked to the sand friction angle. The critical depth ratio increases with friction angle and is greater in denser sands under uplift loading. This study contributes in the following ways: (1) developing an improved analytical framework for uplift prediction, (2) introducing a friction-based critical depth ratio concept, and (3) establishing an empirical OCR relationship for sand. Full article

Marine biofouling significantly impacts vessel operational efficiency, with mussel species being particularly problematic due to their rapid settlement on biofilm-covered surfaces. This pilot study presents the first explicit test of whether ultrasonic treatment can disrupt the biofilm–larva interaction pathway that facilitates mussel settlement. The study evaluated ultrasonic treatment (28 kHz) as a preventive antifouling strategy targeting the mixed microbial biofilm-mediated settlement pathway of Mytilus edulis. A controlled laboratory experiment compared settlement rates on biofilm-conditioned (2.5-week mixed microbial biofilm development) and unconditioned steel plates with and without ultrasonic treatment. Under control conditions, biofilm presence increased mussel settlement odds by 49-fold (p < 0.001). Ultrasonic treatment eliminated this biofilm enhancement, maintaining settlement at baseline levels (odds ratio: 1.3, p = 0.84). The mechanism remains unclear but may involve biofilm disruption, larval behavioral avoidance, or interference with chemical cues. While limited replication (n = 2, temporal replicates, one tank per treatment per replicate) constrains statistical power and inference, the large effect size and consistency across replicates warrant additional investigation. If confirmed by increased replication and mechanistic studies, ultrasonic treatment could provide sustainable antifouling protection without chemical discharge. Full article

Liquid sloshing in partially filled tanks is commonly studied because of its influence on vehicle stability, structural loading, and control performance. In experimental investigations, sloshing measurements can be contaminated by mechanically induced fluid–structure interactions originating from the actuation system itself. This study presents a bench-scale experimental investigation of the interaction between static magnetic fields and the dynamic response of a mechanically excited water-tank system, with particular emphasis on distinguishing sloshing-related motion from higher-frequency mechanical effects. A rectangular acrylic tank was subjected to near-resonant horizontal excitation at a fixed fill height. A ferromagnetic steel plate was mounted externally beneath the tank and kept identical in all experiments, while either permanent magnets or mass-matched nonmagnetic dummies were attached externally to one sidewall. Two configurations were examined: a symmetric split-wall layout (15 + 15) magnets and a single-wall high-field arrangement with 30 magnets (Mag–30@L) together with its dummy control (Dummy–30@L). The center-of-gravity motion ${\mathrm{CG}}_y\left(t\right)$ was reconstructed from four load cells and analyzed in the time and frequency domains. Band-limited analysis of the primary sloshing mode near 0.55 Hz revealed no statistically significant influence of the magnetic field, indicating that static magnets do not measurably affect the fundamental sloshing dynamics under the present conditions. In contrast, a higher-frequency response component in the 10–20 Hz range, attributed to mechanically induced fluid–structure interaction associated with actuator reversal dynamics, was consistently attenuated when magnets were present; this component is absent in corresponding CFD simulations and is, therefore, not associated with sloshing motion. Given the extremely small magnetic Reynolds and Stuart numbers for water, the observations do not support any volumetric magnetohydrodynamic mechanism; instead, they demonstrate a modest magnetic influence on a mechanically excited, high-frequency coupled mode specific to the present experimental system. The study is intentionally limited to bench scale and provides a reproducible dataset that may inform future investigations of magnetically influenced fluid–structure interactions in experimental sloshing rigs. Full article

Ports pose distinctive monitoring challenges due to harsh marine conditions, mixed construction typologies, and heterogeneous ground conditions. These factors complicate the routine use of satellite InSAR, especially when medium-resolution scatterers must be reliably attributed to specific assets for risk and asset management decisions. In current practice, persistent and distributed scatterer (PS/DS) points are often interpreted in map view without an explicit positional uncertainty model or systematic linkage to three-dimensional infrastructure geometry. We present an end-to-end Differential InSAR framework tailored to large ports that fuses medium-resolution Sentinel-1 Level 2 Co-registered Single-Look Complex (L2-CSLC) stacks with high-resolution airborne LiDAR at the post-processing stage. For the Port of Bahía de Algeciras (Spain), we process 123 Sentinel-1A/B images (2020–2022) in ascending and descending geometry using PS/DS time-series analysis with ETAD-like timing corrections and RAiDER tropospheric/ionospheric mitigation. LiDAR is then used to (i) derive look-specific shadow/layover masks and (ii) perform a whitening-transformed nearest-neighbor association that assigns PS/DS points to LiDAR points under an explicit range–azimuth–cross-range (RAC) uncertainty ellipsoid. The RAC standard deviations $({\sigma }_r,{\sigma }_a,{\sigma }_c)$ are derived from the effective CSLC range/azimuth resolution and from empirical height correction statistics, providing a geometry- and data-informed prior on positional uncertainty. Finally, we render dual-geometry red–green composites (ascending to R, descending to G; shared normalization) on the LiDAR point cloud, enabling consistent inspection in plan and elevation. Across asset types, rigid steel/concrete elements (trestles, quay faces, and dolphins) sustain high coherence, small whitened offsets, and stable backscatter in both looks; cylindrical storage tanks are bright but exhibit look-dependent visibility and larger cross-range residuals due to height and curvature; and container yards and vessels show high amplitude dispersion and lower temporal coherence driven by operations. Overall, LiDAR-assisted whitening-based linking reduces effective positional ambiguity and improves structure-specific attribution for most scatterers across the port. The fusion products, geometry-aware linking plus three-dimensional dual-geometry RGB, enhance the interpretability of medium-resolution SAR and provide a transferable, port-oriented basis for integrating deformation evidence into risk and asset management workflows. Full article

In this study, two types of submerged arc welding (SAW) wires were prepared—one without cerium (Ce) and another containing 0.14 wt.% Ce. Deposition experiments were carried out on corrosion-resistant crude oil storage tank steel plates using a multi-layer, multi-pass welding process. Through a combination of microstructural characterization techniques, including optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM), along with mechanical property testing, a systematic investigation was conducted to evaluate the influence of Ce on the weld metal microstructure and its impact toughness at −20 °C. The results reveal that Ce introduced via the welding wire into the weld seam refines and disperses inclusions, leading to the formation of composite inclusions primarily composed of Ce₂O₃, Ce₂O₂S, and CeS. These Ce-enriched inclusions serve as heterogeneous nucleation sites, increasing the area fraction of acicular ferrite (AF) within the weld columnar grain region from 52% to 83%, and within the heat-affected zone from 20% to 37%. Correspondingly, the proportions of blocky and polygonal ferrite decrease, while the size of martensite/austenite (M/A) constituents is reduced. The addition of Ce thus diminishes the size of hard phase inclusions and M/A constituents in the weld metal, enhancing the critical fracture stress and increasing the energy required for crack initiation. Meanwhile, the higher proportion of AF elevates the density of high-angle grain boundaries, thereby improving crack propagation resistance. These combined effects raise the −20 °C impact energy of the weld metal from 117 J to 197 J. Full article

To enhance the anti-corrosion performance of storage tanks, Ni–SiC composites were successfully fabricated on the surface of Q345 steel substrate via the ultrasonic electrodeposition technique. The influence of ultrasonic power on the surface morphology, element content, phase structure, and anti-corrosion performance of Ni–SiC composites were explored utilizing a scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and an electrochemical workstation, respectively. SEM images showed that the Ni–SiC composites obtained at 120 W had a flat, dense surface morphology, with a uniform distribution of SiC nanoparticles (NPs) and a refined size of nickel grains. Meanwhile, the Si content (7.3 wt.%) of Ni–SiC composites prepared at 120 W was obviously higher than those obtained at 0 W (4.8 wt.%) and 60 W (6.1 wt.%). The thicknesses and adhesion force of Ni–SiC composites manufactured at 120 W were the largest of 103.5 μm and 51.2 N, respectively. XRD patterns presented that the diffraction peaks intensity and width of Ni–SiC composites manufactured at 120 W were lower and broader than that of Ni–SiC composites manufactured at 0 W and 60 W. A corrosion test illustrated that the Ni–SiC composites prepared at 120 W had the lowest corrosion current of 3.5 × 10⁻³ mA/cm², the lowest corrosive weight loss (4.2 mg) and corrosion rate (0.06 mg/h), while the corrosion potential was the highest of −0.41 V, which demonstrated the best anti-corrosion performance. In addition, the co-deposition mechanism of SiC NPs and Ni²⁺ ions was also analyzed. Full article

This study evaluated the feasibility of culturing Seriola lalandi in a low-cost recirculating aquaculture system (RAS) in an arid region of northern Chile, aiming to establish strategies for broodstock farming and diversify national aquaculture. The system was designed as a low-cost recirculating aquaculture system (RAS) built with locally available materials, such as galvanized corrugated steel panels and flexible plastic liners, instead of specialized aquaculture tanks. Its modular configuration, based on gravity-fed filtration using sedimentation, sand, and disc filters, allows efficient water reuse with minimal energy consumption and a daily water turnover of 12 times the total volume. This design significantly reduced construction and operational costs, making it a feasible option for aquaculture development in arid regions with limited water resources. Over an 8-month period, 46 S. lalandi individuals were used, and the results showed successful physiological adaptation of the specimens to confinement, as evidenced by low mortality, progressive acceptance of formulated feed, and sustained growth. Individual weights progressively increased, with averages ranging from 675 to 1435 g, and the specific growth rate (SGR) fluctuated between 0.14 and 0.43% per day. Fulton’s condition factor (K) remained in an adequate range between 2.4 and 2.8, suggesting good physical condition of the sampled individuals. Water quality within the RAS system was maintained within acceptable parameters, although a strong negative correlation between temperature and dissolved oxygen was recorded (Spearman coefficient = −0.71, p < 0.001), highlighting the importance of monitoring these factors in warm environments. The lack of adequate protocols for the adaptation of marine species in arid areas, such as northern Chile, has limited aquaculture development in these regions. This study addresses this problem by assessing the feasibility of a low-cost recirculating system (RAS) for the cultivation of S. lalandi under conditions of water scarcity, with the aim of diversifying the national aquaculture in arid zones. Full article

A pilot-scale reactor prototype was designed to produce hydrocarbons through the catalytic pyrolysis process of low-density polyethylene, thereby extending its life cycle and contributing to energy efficiency and sustainability. The reactor consists of a stainless-steel tank encased in a ceramic jacket with refractory cement and clay bricks. The tank, made of 304 stainless steel, ensures mechanical strength and efficient heat transfer to the reactor core. A spiral condenser was incorporated into a water tank to cool the vapors and recover the liquid oil. The insulating materials, ceramic, refractory cement and clay brick, demonstrated a high combined thermal resistance of 0.159 m²·K/W. Simulations and energy flow calculations demonstrated that heat is efficiently directed to the reactor core, reaching 350 °C with only 3000–3800 W, while the outside of the jacket remained close to 32 °C. These results confirm that the proposed design improves thermal efficiency and optimizes energy use for catalytic pyrolysis. The novelty of this design lies in its energy-efficient configuration, which can be replicated in rural regions worldwide due to the accessibility of its construction materials. This reactor was developed based on a smaller-scale model that previously yielded excellent results. Full article

The external floating roof of a large storage tank directly covers the liquid surface as the liquid level rises and falls, enhancing the tank’s safety and environmental performance. It is fabricated from thin SA516 Gr.70 steel plates, with a carbon equivalent of 0.37% calculated according to AWS standards, using single-sided butt welding. Such plates are susceptible to welding-induced deformations, resulting in irregular warping of the bottom plate. Current research on floating roofs for storage tanks mostly relies on idealized models that assume no deformation, thereby neglecting the actual deformation characteristics of the floating roof structure. To address this, the present study develops an automated modeling approach that reconstructs a three-dimensional floating roof model based on measured deformation data, accurately capturing the initial irregular geometry of the bottom plate. This method employs parametric numerical reconstruction and automatic finite element model generation techniques, enabling efficient creation of the irregular initial deformation caused by welding of the floating roof bottom plate and its automatic integration into the finite element analysis process. It overcomes the inefficiencies, inconsistent accuracy, and challenges associated with traditional manual modeling when conducting large-scale strength analyses under in-service conditions. Based on this research, a strength analysis of the deformed floating roof structure was conducted under in-service conditions, including normal floating, extreme rainfall, and outrigger contact scenarios. An idealized geometric model was also established for comparative analysis. The results indicate that under the normal floating condition, the initial irregular deformation increases the local stress peak of the floating roof bottom plate by 19%, while the maximum positive and negative displacements increase by 22% and 83%, respectively. Under extreme uniform rainfall conditions, it raises the stress peak of the bottom plate by 24%, with maximum positive and negative displacements increasing by 21% and 28%, respectively. Under the extreme non-uniform rainfall condition, it significantly elevates the stress peak of the bottom plate by 227%, and the maximum positive and negative displacements increase by 45% and 47%, respectively. Under the outrigger bottoming condition, it increases the local stress peak of the bottom plate by 25%, with maximum positive and negative displacements remaining similar. The initial irregular deformation not only significantly amplifies the stress and displacement responses of the floating roof bottom plate but also intensifies the deformation response of the top plate through structural stiffness weakening and deformation coupling, thereby reducing the safety margin of the floating roof structure. This study fills the knowledge gap regarding the effect of welding-induced irregular deformation on floating roof performance and provides a validated workflow for automated modeling and mechanical assessment of large-scale welded steel structures. Full article

Hydrogen serves as a key clean-energy carrier, with the main hurdles lying in safe, efficient transport and storage (gas or liquid) and in end-use energy conversion. Liquid hydrogen (LH), as a high-density method of storage and transportation, presents cryogenic insulation as its key technical issues. In LH storage tanks, the performance of high vacuum multilayer insulation (HVMLI) will decline due to hydrogen release and leakage from the microscopic pores of steel, which significantly destroy the vacuum layer. The accumulation of residual gases will accelerate thermal failure, shorten the service life of storage tanks and increase safety risks. Adsorption is the most effective strategy for removing residual gases. This review aims to elucidate materials, methods, and design approaches related to hydrogen storage. First, it summarizes adsorbents used in liquid hydrogen storage tanks, including cryogenic adsorbents, metal oxides, zeolite molecular sieves, and non-volatile compounds. Second, it explores experimental testing methods and applications of hydrogen adsorbents in storage tanks, analyzing key challenges faced in practical applications and corresponding countermeasures. Finally, it proposes research prospects for exploring novel adsorbents and developing integrated systems. Full article

This study reviews and experimentally investigates critical logistics and transport models in stainless-steel (SS) fluid storage tanks, focusing on stainless steel grades 316 and 304L. Conceptual vessel schematics emphasize hygienic drainability, refill uniformity, and thermal control, supported by representative 316L properties for heat-transfer, stress, and fluid–structure analyses. At the logistics scale, modelling integrates component-level simulations, computational fluid dynamics (CFD), and Finite Element Method (FEM) with network-level approaches, such as Continuous Approximation, to address facility location, refilling schedules, and demand variability. Experimental characterization using EDS and XRF confirmed the expected Cr/Ni backbone and grade-consistent Mo in 316, while unexpected C, Mn, and Cu readings were attributed to instrumental limits or statistical variance. Unexpected detection of Europium in 304L highlights the need for further mechanical testing. Overall, combining simulation, logistics modelling, and compositional verification offers a coherent framework for safe, efficient, and thermally reliable stainless-steel tank design. Full article

Concentrated Solar Power (CSP) technology is advancing toward higher operating temperatures and lower costs: current systems operate at 565 °C, while next-generation systems are targeted to reach 800 °C to overcome efficiency limitations. In this context, low-cost, adaptable molten chloride salts have emerged as ideal heat transfer and thermal energy storage media. Metallic materials are susceptible to performance degradation under such conditions, which not only shortens equipment service life but also entails potential safety hazards. Thus, the development of alloy protection technologies resistant to molten salt corrosion has become an urgent priority for the deployment of next-generation CSP plants. Research has indicated that high-aluminum stainless steel is a promising candidate due to its unique advantages: it can form a stable Al₂O₃ protective film in oxygen-containing anionic environments, effectively inhibiting the dissolution of Cr, Fe, and other elements, and preventing the penetration of corrosive species. Additionally, the incorporation of magnesium-based corrosion inhibitors into MgCl₂-NaCl-KCl ternary molten salt systems has been proven to be an economically viable and efficient corrosion mitigation strategy. This study focused on high-aluminum 310S heat-resistant steel, with its performance validated through targeted experiments: samples subjected to pre-oxidation at 800 °C for 2 h were immersed in a specific ternary molten salt mixture (20.4 wt.% KCl, 55.1 wt.% MgCl₂, 24.5 wt.% NaCl) containing magnesium corrosion inhibitors, followed by a 600 h static corrosion test at 800 °C. The results revealed that the addition of magnesium significantly enhanced the corrosion resistance of high-aluminum 310S. These findings demonstrate that this material holds application potential in the storage tank and pipeline systems of next-generation CSP plants. Full article