Jin Bao Wang

Sand, a widely used material in construction, often presents challenges in engineering applications due to its loose granular structure. To address this issue, lignosulfonate (LS), an eco-friendly industrial by-product, is explored as a stabilizing agent in this study. This research investigates the effects of LS on the static and dynamic properties of sand, including its impact on compaction, compressive strength, and shear strength. A combination of laboratory tests, including unconfined compressive strength (UCS), direct shear tests, and resonant column tests, was used to evaluate the performance of LS-treated sand under different conditions. The study reveals that LS enhances the compaction, shear strength, and dynamic stiffness of sand, with an optimal LS content of 8%. This work contributes to the development of sustainable geotechnical materials and offers valuable insights for improving soil properties in foundation and subgrade applications under dynamic loading conditions.

Wire Arc Additive Manufacturing holds promise for on-board metal part production in maritime settings, yet its implementation remains limited due to the vibrational instability inherent to shipborne environments. This study addresses this critical technological barrier by analyzing the effects of marine vibrations on process stability and proposing an integrated solution based on adaptive process control, gyrostabilized platforms, and real-time monitoring systems. The research establishes specific technical requirements for WAAM instrumentation under maritime conditions and evaluates the capabilities and limitations of existing hardware and software tools. A set of engineering recommendations is presented for improving digital modeling, thermal–mechanical monitoring, and feedback control systems. Additionally, the study highlights material-related challenges by examining the influence of alloy properties on print quality under dynamic loads. The proposed approach enhances WAAM process resilience, laying the groundwork for reliable, high-quality additive manufacturing at sea. These findings are particularly relevant to shipboard maintenance, repair, and remote fabrication tasks, marking a significant step toward the industrial adoption of WAAM in marine engineering.

The application of Wire Arc Additive Manufacturing for metal component fabrication on marine vessels and offshore platforms remains a significant challenge and an under-explored research domain. The primary obstacle lies in the dynamic and complex nature of the maritime environment, which imposes severe constraints on the operational stability of 3D printing systems. Methodologically, the article presents an analysis of the problems of using WAAM technology in the marine environment, as well as a theoretical analysis of the functionality, advantages and limitations of technical and software tools designed to improve the reliability of WAAM technology in marine conditions. The findings indicate that while WAAM offers notable adaptability and flexibility, maintaining print quality remains a challenge due to the high sensitivity of the process to fluctuations in thermal and mechanical conditions, particularly under the influence of shipborne vibrations. To accelerate the adoption of WAAM technology in maritime industries, this study synthesizes existing research aimed at improving instrumentation for effective WAAM implementation. Specific technical requirements for deploying WAAM on marine vessels are identified, alongside a critical assessment of current software and hardware solutions that could enhance the robustness of WAAM in offshore environments. Furthermore, recommendations are provided for advancing digital modeling, real-time monitoring, diagnostic methodologies, and process control to optimize WAAM for marine engineering applications. The study also delineates the functional properties of various metals suitable for WAAM-based manufacturing in maritime settings, highlighting their respective benefits and limitations. Ultimately, enhancing instrumentation for high-quality 3D printing is identified as a key driver for ensuring the competitiveness and innovation potential of WAAM technology in the maritime sector.

Considering the viscoelastic of soft clay, the fractional kelvin model is used to describe the constitutive relationship of soft clay. At the same time, considering that both sides of the soft clay layer have certain permeability, the two-sided semi-permeable boundary is used as its boundary condition. Combined with the cyclic load of different waveforms, the one-dimensional consolidation settlement of saturated soft clay is analyzed. Firstly, the consolidation equation is obtained through Laplace transformation, and the semi-analytic result is obtained by Laplace inverse transformation. The accuracy of the solve method and the model’s applicability are checked by the degradation of boundary conditions and the model. Finally, one-dimensional consolidation settlement under cyclic load with different waveforms is compared.

Hydrated ions can be separated from water by a fast-rotating graphene membrane with pore size larger than hydrated ion sizes.

This study evaluated the Pb(II) sorption capacity of jujube pit biochar (JPB) in aqueous solution, which was derived from jujube pit by pyrolysis and used as a promising and economical adsorbent. More importantly, the utilization of JPB could realize the recycling of agricultural residues. The JPB was characterized using conventional science technologies, including SEM, BET and FT-IR, and the sorption capacity of JPB for lead ions was investigated according to different adsorption parameters, such as the kinetics data, solution pH, isotherms data, coexisting ions of Na⁺ and K⁺, desorption and reusability, and solution temperature. The results of kinetics data suggested that the lead ion adsorption process by JPB could be fast to reach equilibrium within 30 min. Additionally, the adsorption capacity of JPB for Pb(II) was calculated to be maximum for 137.1 mg/g at pH 6.0. More importantly, after five cycles of desorption and reuse, the JPB still reached 70% of its original adsorption capacity. All the results suggested that JPB had a broad application prospect for the purification of lead ions in practical.