Marine Field Research Articles

Tracking information in the field: An assessment of the information needs and services of a field station library

This project examines field station libraries, an undescribed type of library associated with terrestrial and marine field stations. Field stations typically support ecology, geology, and related disciplines with housing, laboratories, and research facilities, which may include various levels of library support. In summer 2022, researchers, instructors, and staff at the University of Michigan Biological Station were interviewed about the library resources and services they use while working and teaching at the field station. Library resources were used throughout teaching and research activities, with one-shot instruction and in-person reference support as the primary contact points between the library and the field station community. The field station library was further defined by the community's need for GIS assistance, map librarianship, research data management, and prior on-site research stored in the institutional repository. Course-based research and place-based research significantly shaped the community's information needs when working at the field station. When characterizing the information and library service needs of the field station community, these services should be placed at the core. While this directly applies to terrestrial field stations, the findings may be applicable to ecology and geology librarianship more generally.

Study on yield limit of steel containment under external pressure considering initial defects

The main objective of floating nuclear power plants (FNPP) is an emerging technology product formed by applying land small-scale nuclear power plant technology to the marine field. The containment structure studied in this article plays a great role in protecting the safety of FNPP’s nuclear power system. When exploring the safety performance of the containment structure under accident conditions, it is necessary to analyze and study the external pressure yield limit of the containment. This study provides a reference basis for the static buckling limit calculation of spherical shell structures similar to steel safety shells. The article adopts a geometric initial defect analysis method based on buckling mode to consider the initial defects of the model and explores the external pressure yield limit of the safety shell through the arc length method. The research results analyzed that the external pressure yield limit of the containment vessel decreased by about 30% under the influence of initial defects and pointed out the weak structural parts of the containment vessel in the buckling analysis.

Latest Research Progress on Nano-Engineered Concrete

As one of the most obvious manifestations of tangible footprint of human civilization on Earth, concrete is largely and widely applied, and has become the largest amount of man-made engineering material in the world. Compared with other engineering materials, concrete consumes less production resource and energy, has fewer harmful by-products, and causes less environmental impact. Additionally, due to its excellent mechanical properties, such as compressive strength and fatigue resistance, along with its water and fire resistance, the infrastructure constructed by applying concrete has the advantages of high safety, durability, and low maintenance. Consequently, concrete remains a reliable choice for sustainable development of the field of human construction and engineering and remains indispensable in the future. However, inherent shortcomings and current performance limitations of concrete do not meet the requirements for the construction and expansion of human living spaces in the future. Moreover, the production and use of large quantities of concrete have a significant impact on resources, energy, and environment. Nanoscience and nanotechnology can be used to understand and control concrete at its fundamental level, enabling the realization of (ultra) high-performance and multifunctional/smart concrete, which in turn can give impetus to addressing the aforementioned challenges and achieving sustainable development. This article focuses on three core research advancements related to enhancement/modification mechanisms, preparation and performance control, and performance and functionality characterization for engineering applications of nanoengineered concrete. It mainly introduces the explanation/principle investigation of scientific phenomena including nano-core effect, nano-core effect zone, nano-core effect-induced enrichment effect for interface enhancement, nano-core effect-induced ultrahigh-density calcium silicate gel, and nanoscale pore structure characteristics, the exploration of advanced technologies for performance modulation and large-scale preparation of nano-engineered concrete (e. g. , surface treatment, self-assembly, and in-situ growth techniques, etc. ) , as well as the understanding gained from the expansion of the properties of nanoengineered concrete and the validation of engineering applications in the fields of civil engineering, transportation, municipal, marine, energy, and military.

Preparation of superhydrophobic shape memory composites with uniform wettability and morphing performance

Superhydrophobic shape memory surfaces have attracted much attention in recent years, as they can intelligently control surface wettability. However, less research has focused on the development of superhydrophobic shape memory materials that can maintain uniform wettability in any morphing shape. It is common in nature that species such as lotus leaves and kingfisher show good superhydrophobicity in any movement under/on water. Based on this inspiration, this work presents a novel superhydrophobic shape memory composite (SSMC) by coupling superhydrophobic coatings and shape memory epoxy composites. The SSMC exhibits excellent water repellency and self-cleaning performance regardless of how it is bent. In addition, its good shape memory effect and variable stiffness characteristics enable it to be potentially used as deployable marine structures and morphing skin of aquatic unmanned aerial vehicles. On the other hand, the SSMC also offers good anti-icing properties and mechanical/chemical robustness that enhance long-term service performance all year round. This research provides a fresh idea for the design of new smart superhydrophobic materials and expands applications in the field of marine and aviation facilities.

INTRODUCTION AND VALIDATION OF A NOVEL CALIBRATION FRAME

Abstract. The use of Photogrammetry is increasingly used by several disciplines, including marine science. Among others, the accuracy of a 3D model generated from images, depends on the quality of the calibration and stability of the camera used to capture the images. For the calibration an optimum 3D geometry is essential to minimise correlations between the camera’s interior orientation parameters. For the calibration, usually various different types of calibration frames are used. However, in practice, it can be challenging to use these frames when working in underwater environments. Calibration frames can be bulky, which makes them difficult to handle and transport, especially in boats where space is at a premium. This study aimed to develop a collapsible (and thereby portable) calibration frame, which is more practical for marine field data capture. The proposed collapsible calibration frame is validated in-air and underwater. Overall, three tests are performed. Firstly, the reliability of the frame is validated, i.e. if the collapsible frame can be put together in such a way that the Ground Control Points (GCPs) on the frame have unchanged positions relative to each other. The test showed a very small bias which could be removed by changing to a baseline assessment. Secondly, repeatability is validated, i.e. if the same results can be achieved for different software and camera combinations when using the same baselines. The test showed a clear downwards trend of the results for lower-grad cameras. However, all adjustments using the different software solutions and cameras show that the frame is suitable for application in-air. The final test is an underwater performance test which verified that the frame is usable achieving root-mean-squared error values of below 2 mm when using baselines.

Slippery Porous-Liquid-Infused Porous Surface (SPIPS) with On-Demand Responsive Switching between "Defensive" and "Offensive" Antifouling Modes.

Slippery liquid-infused porous surfaces (SLIPS) have received widespread attention in the antifouling field. However, the reduction in antifouling performance caused by lubricant loss limits their application in marine antifouling. Herein, inspired by the skin of a poison dart frog which contains venom glands and mucus, a porous liquid (PL) based on ZIF-8 is prepared as a lubricant and injected into a silicone polyurethane (SPU) matrix to construct a new type of SLIPS for marine antifouling applications: the slippery porous-liquid-infused porous surface (SPIPS). The SPIPS consists of a responsive antifoulant-releasing switch between "defensive" and "offensive" antifouling modes to intelligently enhance the antifouling effect after lubricant loss. The SPIPS can adjust antifouling performance to meet the antifouling requirements under different light conditions. The wastage of antifoulants is reduced, thereby effectively maintaining the durability and service life of SLIPS materials. The SPIPS exhibits efficient lubricant self-replenishment, self-cleaning, anti-protein, anti-bacterial, anti-algal, and self-healing (97.48%) properties. Furthermore, it shows satisfactory 360-day antifouling performance in actual marine fields during boom seasons, demonstrating the longest antifouling lifespan in the field tests of reported SLIPS coatings. Hence, the SPIPS can effectively promote the development of SLIPS for neritic antifouling.

Advanced Marine Antifouling Hydrogels Based on 7-Amino-4-methylcoumarin Fluorescence Driven by Rare-Earth Phosphorescence.

At present, there are very few reports on the combination of phosphorescence and fluorescence in the field of pollution prevention. A composite antibacterial agent was designed to store energy by using the phosphorescence effect of rare earth oxides, emit light at night, and stimulate 7-amino-4-methylcoumarin to produce fluorescence and prevent algae from adhering. When complexed with PVA, it exhibited excellent characteristics as an all-weather autocatalytic phosphorescence-fluorescence antifouling hydrogel. The rare earth phosphorescent powder was prepared in a high-temperature tube furnace, coated with SiO2 on the surface for waterproofing, and then grafted with 7-amino-4-methylcoumarin to obtain a composite antibacterial agent with a phosphorescence-fluorescence effect. The composite antibacterial agent was added with PVA to obtain a hydrogel, which exhibited bactericidal rates of more than 99.98% against both Gram-positive and Gram-negative bacteria after 48 h. The results of fluorescence staining showed that the coverage rate of dead bacteria reached 41.6% after 24 h. The tensile strength of the antifouling hydrogel is up to 1.49 MPa, which is strong enough for real marine environments. Moreover, the algae coverage area of the composite hydrogel under natural light was only 2.7%, representing a 10-fold reduction compared with the control. The antifouling hydrogel has good antipollution and algae suppression performance, which is due to the fact that the rare earth phosphorescent powder when exposed to sunlight can provide a light source to stimulate 7-amino-4-methylcoumarin fluorescence at night and thereby prevent algae adhesion. After testing in the marine field and the real sea test when wrapped in a fishing net, the excellent antifouling performance was demonstrated. The functional hydrogel has great application potential in the protection of seawater-exposed structures, such as bridges and bay ports.

Robust multi-model mobile target localization scheme based on underwater acoustic sensor networks

Underwater mobile target localization based on underwater acoustic sensor networks (UASNs) is a critical application in marine fields. However, the mobility of underwater targets, asynchronous reception of localization information, stratification effects, and unknown measurement losses make UASN-assisted mobile target localization difficult. To address these issues, this study proposes a robust multi-model mobile target localization scheme (RMML) based on UASNs. The RMML suggests a simplified approach for optimal localization reference node selection based on the Cramér-Rao lower bound. This approach improves the localization accuracy of a mobile target by periodically selecting nodes that provide high-quality localization references. Using the localization reference provided by the selected nodes, a robust mobile target localization algorithm is developed based on an interacting multiple model and unscented Kalman filter. In this algorithm, a multipoint prediction method and ray tracing method are jointly proposed to improve the target state estimation accuracy under the asynchronous reception of localization information and the stratification effect. Maximum a posteriori probability estimation is used to estimate measurement loss, and pseudo-residuals are constructed based on the estimated measurement loss to improve the localization accuracy and robustness of the algorithm. Finally, extensive simulations and experiments are performed to verify the effectiveness of the RMML.

Impact of structural geometry of tilted fault blocks on hydrocarbon entrapment and deposition of syn-rift clastic reservoirs: Belayim Marine field (Gulf of Suez rift)

Belayim Marine oilfield is representative of the Gulf of Suez fields with hydrocarbon production from pre-rift and syn-rift reservoirs. Detailed subsurface mapping using a complete 3D seismic and borehole dataset throws light on the trapping mechanisms of tilted fault blocks in rift basins where the strike of the tilted block is parallel to the bounding fault. For such one-way tilted fault traps, linkage of rift-parallel and rift-oblique faults at the updip sides of the tilted blocks is necessary for trap integrity of laterally continuous reservoirs like the Nubia Sandstone. For laterally discontinuous reservoirs like tidal sand bars aligned normal or oblique to the block-bounding faults, a combination trap can be laterally closed by lateral change in facies of the reservoir unit along fault strike. Fault sealing of the proved hydrocarbon traps is mainly through juxtaposition. Shale smearing is valid for thick shale units with reasonable fault displacement and shale gouge is a proven sealing mechanism especially in clay-rich units. The ductile nature of syn-rift sediments leads to fault-propagation folding above the main-bounding faults of tilted fault blocks where folding is the trapping mechanism of these syn-rift reservoirs.The structural geometry of tilted fault blocks also controls the distribution of syn-rift reservoirs as the linkage of rift-parallel and rift-oblique faults controls the entry of main valleys transporting syn-rift clastics into the basin. Longitudinal depressions sculptured at the crests of tilted fault blocks represent another location for deposition of syn-rift reservoirs.

P. pavoninus‐Inspired Smart Slips Marine Antifouling Coating Based on Coumarin: Antifouling Durability and Adaptive Adjustability of Lubrication

AbstractSlippery liquid‐infused porous surface (SLIPS) is received widespread attention in the antifouling field because of its dynamic slippery surface, but the limited effect of physical “anti‐adherence” and the problem of lubricant loss restrict its application for practical marine antifouling. Inspired by the self‐defensive function of P. pavoninus’s poisonous mucus, a SLIPS based on the reversible chemical bonds and the antibacterial effect of coumarin (CmSLIPS) is prepared, which addresses these disadvantages by responsively adaptive lubricity and durability. The CmSLIPS enables the “locking” and “unlocking” mode between lubricant and matrix via the reversible photodimerization of coumarin. It regulates the surface lubricity to adapt to the antifouling demand. The reversible chemical bonds of lubricant and matrix reduce lubricant loss and enhance the lubricant stability and antifouling durability. In addition to the physical anti‐adhesive barrier of SLIPS, the excellent antimicrobial property of coumarin groups further enhances the “biocidal” antifouling effect to improve long‐term antifouling durability. In summary, the CmSLIPS has surface stability, durability, responsively adaptive lubricity, efficient self‐cleaning, anti‐protein, anti‐bacterial, anti‐algae, self‐healing (92.85%) properties and 150‐day marine field antifouling performance during boom seasons, which maintains the satisfactory antifouling performance in the harsh marine environment and demonstrates the promising application in neritic sea equipment.

Enhanced antifouling capability of PDMS/Cu2O-anchored Fe-based amorphous coatings

Biofouling and corrosion, caused by marine organisms, pose significant challenges in the marine industry. Fe-based amorphous coatings have demonstrated remarkable corrosion resistance and hold promise for marine applications. However, they lack sufficient antifouling properties. Herein, we present a novel approach to enhance the antifouling properties of Fe-based amorphous coatings through co-modification with polydimethylsiloxane (PDMS) and cuprous oxide (Cu2O). The PDMS/Cu2O antifouling layer was successfully applied to the Fe-based amorphous coating with the bonding strength exceeding 2 MPa. The PDMS/Cu2O- anchored Fe-based amorphous coating (designated as PCA coating) demonstrates outstanding antifouling performance, showcasing 83.9 % resistance to protein, 99 % resistance to algae, high resistance to bacteria and mussel adhesion, and successful antifouling performance in practical marine field tests. The remarkable antifouling properties of the PCA coating stem from its dual capacity of killing and resisting to deter organism attachment across different length scales. And the enhanced anti-corrosion performance of the PCA coating was verified through electrochemical impedance spectra (EIS). This study presents an innovative approach to designing marine coatings with anti-fouling and anti-corrosion capabilities.

Blue-ringed Octopus inspired slippery coating with physico-chemical synergistic antifouling properties

Bionic superhydrophobic and slippery liquid-infused porous surfaces (SLIPS) have attracted great interest due to their antifouling properties, while the poor stability, complex preparation of porous structures and rapid loss of lubricants, as well as only possessing physical antifouling capability, have hindered their further application. Herein, inspired by the Blue-ringed Octopus’ defensive equipment of slippery skin and toxin secretion when faced with predators, an antifouling slippery coating containing repellent is easily prepared. The repellent capsaicin physically connected to the slippery networks can be activated to accelerate release in response to the changes in pH caused by bacterial secretions, and the adhesion resistance of the coating is improved by 99 % compared to aluminum plates, both conclusions confirmed by experimental and computational data. The anti-adhesive properties of the slippery surface, combined with the repellent properties of capsaicin provides the coating with excellent synergistic physico-chemical antifouling performance. This is demonstrated by the fact that the surface of the coating remains clear after contamination with proteins, bacteria and diatoms, as well as after 65 days of marine field testing. Additionally, the slippery surface has self-healing and outstanding anticorrosion ability. Therefore, the eco-friendly coating has promising application prospects in marine field for antifouling purposes.

A highly antifouling and eco-friendly hydrogel coating based on capsaicin derivative -functionalized polymer

Antifouling hydrogels have received extensive attention in the field of marine antifouling due to their excellent hydrophilicity and environmental friendliness. However, the antifouling applications of traditional hydrogels are limited by their poor antibacterial properties, and capsaicin derivatives, as nontoxic and environmentally friendly antifoulants, can be used to improve the antibacterial properties of hydrogels. From the perspective of practical application, hydrogels were obtained by crosslinking the copolymer of the capsaicin derivative N,N'-((4,5,6-trihydroxy-1,3-phenylene) bis (methylene)) diacrylamide (TPA), lipophilic monomers and hydrophilic monomers. This hydrogel exhibited anti-protein performance due to its hydrophilicity, and the capsaicin derivative caused the hydrogel coating to exhibit excellent algae inhibition performance (the minimum adhesion density of diatoms on the surface of the hydrogel coating was less than 440 cells/mm2), better algae anti-adhesion abilities than hydrogel reported in the other paper, and antibacterial effects (the antibacterial rate was more than 95%). After 73 d of panel testing in a real marine environment, there was still a good antifouling effect in the hydrogel coating. Hence, the antifouling performance was improved significantly by capsaicin derivative (TPA)-functionalized hydrogel coating. A new strategy is provided in this study for the preparation of hydrogels with superior marine antifouling properties.

Implication of gender mainstreaming on policy-making for sustainable fisheries development in China

Currently, gender mainstreaming is widely recognized by the international community as an essential component of social development. Increasing attention is also being directed toward its significant role in the field of marine and fisheries, especially because gender equality-responsive fisheries development is believed to be a significant impulse for the continued advancement of this field. An analysis of the role of gender mainstreaming in fisheries development reveals that the long-term challenges faced by Chinese women in fisheries are closely tied to the absence of the gender perspective in existing fishery policies. In recent years, international organizations, such as the Food and Agriculture Organization of the United Nations, along with various regions and countries, have accumulated extensive experience and achieved notable progress in promoting gender mainstreaming in fisheries. Furthermore, they have established successful models for the scientific implementation of gender mainstreaming from the top down and with diverse perspectives, thus providing valuable insights for China to incorporate gender mainstreaming in policymaking. As China endeavors to foster high-quality marine and fisheries development while positioning itself as a responsible fishery power, it is imperative for the country to proactively address gender issues within the fisheries sector. Drawing on international best practices and considering China’s national conditions, this paper proposes the integration of a gender perspective into China’s fisheries policy by raising policymakers’ gender awareness, conducting dynamic monitoring and evaluation of the status of women in the fisheries sector, encouraging the active involvement of women and fisheries organizations in policymaking, and promoting research on gender issues in fisheries, all of which can bridge the gap in gender responsiveness within China’s fisheries policy system.

Superhydrophobic Fe-based amorphous alloy coatings with excellent anti-fouling and anti-corrosion properties by picosecond laser texturing

Producing superhydrophobic surfaces on the amorphous alloy coatings with excellent anti-corrosion and anti-fouling properties offers a promising strategy to broaden the applications of amorphous alloys in marine fields. In this work, the superhydrophobic surfaces on the Fe-based amorphous alloy coatings with micro-nano hierarchical structures were fabricated using picosecond pulsed laser texturing (LT) and surface chemical modification. The fabricated superhydrophobic coating surfaces have achieved a maximum contact angle of 166.5°and a minimum sliding angle of 3.6°. Additionally, these produced coatings also demonstrate outstanding self-cleaning and anti-fouling properties for preventing surface contamination. The superhydrophobicity originated from the formation of micro-nano hierarchical structures and the grafting of organic compounds with low surface free energy on the LT fabricated surfaces. The changes in wettability were attributed to the differences in the solid–liquid interfacial area fractions. The electrochemistry tests revealed that the corrosion resistance of the produced coatings with superhydrophobic surfaces had improved considerably compared with the as-sprayed amorphous alloy coatings, which could broaden the functional applications of the Fe-based amorphous alloy coatings.

R&D of a low-complexity acoustic communication payload for small-size AUV

Due to its features of low-cost, deployment-convenience and low detection probability, small size AUV is drawing more and more attention from diverse marine fields. While the technique of acoustic communication is capable of enabling wireless link of small size AUV, difficulties caused by adverse underwater acoustic mobile channel such as multipath, Doppler and noise pose significant challenges. Moreover, extremely strict constaints in terms of size, power supply and real-time caculation capability means that R&D of acoustic communication payload need to seek a tradeoff between the algorithm performance and system overhead. To deal with the abovementioned hurdles, a lightweight acoustic communication payload for small-size AUV is designed. Specifically, the proposed payload adopts symbol-wise low-complexity Doppler estimation and compenstaion process, which is incorporated with a compact channel equalizer to achieve reliable mobile communication under Doppler and multipath conditions. The hardware and software design associated with the efficient system implementation of the proposed scheme is given. Finally, lake trial results performed based on small size AUV equiped with the proposed acoustic communication payload is presented to verify its effectiveness.

Effect of cerium on the microstructure and anti-corrosion performance of Al-Zn coatings

With the increasing application scope of aluminum alloys in the marine field, exploring the surface anti-corrosion technologies of aluminum alloys is becoming more and more important. In current industries, thermal spraying is generally used to prepare AlZn coatings for surface protection. In this paper, AlZn coating and Al-Zn-Ce coating were prepared by flame spraying technology, and the effects of adding rare earth element Ce on the microstructure and corrosion resistance of AlZn coating were systematically studied by using OM, SEM, XPS, LCSM and electrochemical corrosion tests. The results show that the addition of Ce is conducive to promoting the mobility and solidification shrinkage of AlZn alloy melt, thereby increasing the density of the coating while decreasing porosity and roughness. Moreover, adding Ce improves the hardness and wear resistance of the AlZn coating. During immersion, adding a trace of Ce to the AlZn coating will affect the passivation process and the formation of the passivation film, endowing the coating with a strong passivation ability and thus improving the corrosion resistance of the coating.

The Authority of Lampung Provincial Government in Managing Fisheries Resources in Era of Regional Autonomy

The global COVID-19 outbreak has had a major impact on the marine and fisheries industry in Indonesia. This is also felt by fishermen in Lampung Province with the decline in demand for fishery products in the domestic and international markets in Lampung Province. The overall decline in the fisheries production cycle is influenced by the decline in demand from consumers. The local government has an important role to help restore the condition. The problem in this research is how the authority of the local government of Lampung Province in the management of fisheries resources in the era of regional autonomy and how the efforts of the marine and fisheries office of Lampung Province in an effort to achieve fisheries production in the era of regional autonomy. The research method used is normative research with statute approach. The results of this study are in accordance with the Governor's Regulation on the determination of the main tasks and functions of the Lampung Province Maritime and Fisheries Service as an implementing element of local government in the field of marine and fisheries led by a Head of Service who is responsible to the Governor. he goal is to implement the commitment of the Governor and Deputy Governor elected in 2019-2024 on marine and the Berjaya Fishermen Program to prioritize the welfare of the fishing industry, especially fishermen and their families. The Lampung Provincial Maritime and Fisheries Service provides solutions in the form of feed assistance in collaboration with Lampung University, fish nurseries and distribution in four districts and cities as well as Mobilizing registration and licensing to increase the capacity of fishermen and facilitate licensing and shipping documentation.

A reliability-based design and optimization strategy using a novel MPP searching method for maritime engineering structures

PurposeIn order to solve the problems faced by First Order Reliability Method (FORM) and First Order Saddlepoint Approximation (FOSA) in structural reliability optimization, this paper aims to propose a new Reliability-based Design Optimization (RBDO) strategy for offshore engineering structures based on Original Probabilistic Model (OPM) decoupling strategy. The application of this innovative technique to other maritime structures has the potential to substantially improve their design process by optimizing cost and enhancing structural reliability.Design/methodology/approachIn the strategy proposed by this paper, sequential optimization and reliability assessment method and surrogate model are used to improve the efficiency for solving RBDO. The strategy is applied to the analysis of two marine engineering structure cases of ship cargo hold structure and frame ring of underwater skirt pile gripper. The effectiveness of the method is proved by comparing the original design and the optimized results.FindingsIn this paper, the proposed new RBDO strategy is used to optimize the design of the ship cargo hold structure and the frame ring of the underwater skirt pile gripper. According to the results obtained, compared with the original design, the structure of optimization design has better reliability and stability, and reduces the risk of failure. This optimization can also better balance the relationship between performance and cost. Therefore, it is recommended for related RBDO problems in the field of marine engineering.Originality/valueIn view of the limitations of FORM and FOSA that may produce multiple MPPs for a single performance function, the new RBDO strategy proposed in this study provides valuable insights and robust methods for the optimization design of offshore engineering structures. It emphasizes the importance of combining advanced MPP search technology and integrating SORA and surrogate models to achieve more economical and reliable design.

A Preliminary Study of a Multifunctional DOC/Wet-Scrubber Capable to Reduce both Chemical and Acoustic Emissions in Marine Field

A Preliminary Study of a Multifunctional DOC/Wet-Scrubber Capable to Reduce both Chemical and Acoustic Emissions in Marine Field