Suction bucket foundations have recently been recognized as a cost-effective support structure for offshore wind turbines in both shallow- and deep-sea environments, leading to their increased application in various seabed. In particular, for fixed offshore wind substructures, suction buckets are integrated with their superstructures before installation for successful penetration. Thus, the suction buckets are subjected not only to hydrostatic pressure but also to additional axial loading in the longitudinal direction during suction installation phase. This additional load increases longitudinal stress and contributes to further compression effects. However, research on the influence of such axial loading remains limited in literature. To address this gap, the present study conducts a theoretical investigation into the critical buckling strength of suction bucket foundations under combined hydrostatic–axial loading conditions, thereby supporting more precise and safe design. The governing differential equations are modified to derive new buckling coefficients that account for the combined loading effects. In addition, simplified design equations are proposed by modifying the design parameters specified in the DNV recommendations, along with a new updating method for the buckling coefficient that incorporates the self-weight of the superstructures. Finally, the effect of additional axial loading on the buckling behavior of suction buckets are evaluated.
In this study, the global mean characteristics and spatial distribution differences of the Lorenz energy cycle (LEC) were investigated using four atmospheric reanalysis datasets over 44 years from 1980 to 2023. The global mean values show that the energy terms exhibit relatively small differences among the datasets, with values ranging from − 7.4 to + 3.7
The global expansion of offshore wind turbine (OWT) installations into seismically active regions has heightened concerns about their performance under earthquake loading. Beyond harsh environmental loads, seismic events can severely disrupt OWT operations, potentially resulting in permanent shutdowns. Incorporating soil-structure interaction (SSI) effects significantly influences their resilience and stability—factors that are critical yet poorly understood. Furthermore, the impacts of near-field and far-field ground motions on the seismic SSI behavior of jacket-supported OWTs remain unexplored, representing a critical knowledge gap. Therefore, this study investigates the influence of pulse-like ground motions on the nonlinear dynamic responses of jacket-supported OWT systems, accounting for SSI effects. A high-fidelity numerical model is developed and validated to ensure accuracy within the modeling framework. Following validation, extensive numerical simulations are conducted using earthquake records with and without velocity pulse characteristics. The results elucidate the interplay among pulse-type classifications, SSI effects, and the seismic response of jacket-supported OWTs, thereby supporting improved seismic design and analysis practices for such structures.
In this study, we analyzed the physical and chemical properties of bio-ink prepared using various types and ratios of animal-based gelatin. The pH analysis revealed that as the gelatin ratio increased, the pH decreased, with fish gelatin samples showing the highest pH values (p < 0.05). The color measurements indicated that the lightness (CIE L*) of the 4
Infectious hematopoietic necrosis virus (IHNV) is a significant viral pathogen that affects salmonids, leading to high mortality and substantial economic losses in aquaculture. The current vaccine strategies focus on use of DNA and inactivated vaccines. However, these strategies face limitations concerning biosafety and efficacy. Therefore, in this work, we employed an approach based on the immunoinformatic platform to develop a multi-epitope vaccine against IHNV. For that purpose, we analyzed the glycoprotein of IHNV and identified highly antigenic and non-allergenic cytotoxic T lymphocyte (CTL), helper T lymphocyte (HTL), and B-cell epitopes. The different epitopes were assembled with rational linkers, and the N-terminal flagellin FliC adjuvant was added to enhance immunogenicity. The designed vaccine showed favorable physicochemical properties and high structural stability, which was validated through modeling and refinement. Moreover, the molecular docking of the designed vaccine with toll-like receptor 5 (TLR5) and molecular dynamics simulation revealed stable and strong interactions between the vaccine and TLR5, demonstrating that the designed vaccine can activate innate immunity. Furthermore, in silico immune simulations demonstrate a robust humoral and cellular immune response following multiple doses. These findings provide a promising framework for the development of a novel, safe, and effective vaccine against the IHNV infection in Atlantic salmon.
