Subjects -> EARTH SCIENCES (Total: 771 journals)
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OCEANOGRAPHY (88 journals)

Showing 1 - 77 of 77 Journals sorted by number of followers
Deep Sea Research Part II: Topical Studies in Oceanography     Hybrid Journal   (Followers: 29)
Deep Sea Research Part I : Oceanographic Research Papers     Hybrid Journal   (Followers: 23)
Estuaries and Coasts     Hybrid Journal   (Followers: 23)
Limnology and Oceanography     Hybrid Journal   (Followers: 22)
Progress in Oceanography     Hybrid Journal   (Followers: 21)
Journal of Marine Biology & Oceanography     Hybrid Journal   (Followers: 19)
New Zealand Journal of Marine and Freshwater Research     Hybrid Journal   (Followers: 18)
Journal of Physical Oceanography     Hybrid Journal   (Followers: 18)
Frontiers in Marine Science     Open Access   (Followers: 17)
Journal of Marine Sciences     Open Access   (Followers: 17)
Coastal Engineering     Hybrid Journal   (Followers: 15)
Advances in Oceanography and Limnology     Open Access   (Followers: 15)
Journal of Oceanography     Hybrid Journal   (Followers: 14)
Maritime Studies     Open Access   (Followers: 13)
International Journal of Oceanography     Open Access   (Followers: 12)
Advances in Statistical Climatology, Meteorology and Oceanography     Open Access   (Followers: 11)
Atmospheric and Oceanic Science Letters     Open Access   (Followers: 10)
Bulletin of Marine Science     Full-text available via subscription   (Followers: 9)
Fisheries Oceanography     Hybrid Journal   (Followers: 8)
Journal of Oceanography and Marine Science     Open Access   (Followers: 7)
Open Journal of Marine Science     Open Access   (Followers: 6)
Limnology and Oceanography: Methods     Hybrid Journal   (Followers: 6)
Journal of Operational Oceanography     Hybrid Journal   (Followers: 6)
Physical Oceanography     Hybrid Journal   (Followers: 6)
Paleoceanography and Paleoclimatology     Full-text available via subscription   (Followers: 5)
Marine Science     Open Access   (Followers: 5)
Limnology and Oceanography: Fluids and Environments     Full-text available via subscription   (Followers: 5)
Ocean Yearbook Online     Hybrid Journal   (Followers: 4)
Journal of Oceanology and Limnology     Hybrid Journal   (Followers: 4)
Limnology and Oceanography Letters     Open Access   (Followers: 4)
Journal of Marine Science and Engineering     Open Access   (Followers: 4)
African Journal of Marine Science     Hybrid Journal   (Followers: 4)
Oceanology     Hybrid Journal   (Followers: 3)
Journal of Aquatic Sciences     Full-text available via subscription   (Followers: 3)
Limnology and Oceanography e-Lectures     Open Access   (Followers: 3)
Journal of Coastal Development     Open Access   (Followers: 3)
Ciencias Marinas     Open Access   (Followers: 3)
Journal of Marine Science and Application     Hybrid Journal   (Followers: 3)
Journal of Ocean Engineering and Marine Energy     Hybrid Journal   (Followers: 3)
Tropical Oceanography     Open Access   (Followers: 2)
Indian Journal of Geo-Marine Sciences     Open Access   (Followers: 2)
Mediterranean Marine Science     Open Access   (Followers: 2)
Regional Studies in Marine Science     Hybrid Journal   (Followers: 2)
Annals of Marine Science     Open Access   (Followers: 2)
Limnology and Oceanography: Bulletin     Hybrid Journal   (Followers: 2)
Annals of Limnology and Oceanography     Open Access   (Followers: 2)
Development and Applications of Oceanic Engineering     Open Access   (Followers: 2)
Journal of Ocean Engineering and Technology     Open Access   (Followers: 1)
Ocean Life     Open Access   (Followers: 1)
Marine Systems & Ocean Technology     Hybrid Journal   (Followers: 1)
Journal of Ocean University of China (English Edition)     Hybrid Journal   (Followers: 1)
Marine Life Science & Technology     Hybrid Journal   (Followers: 1)
Journal of Ocean Engineering and Science     Open Access   (Followers: 1)
Coastal Engineering Proceedings : Proceedings of the International Conference on Coastal Engineering     Open Access   (Followers: 1)
Marine Technology Society Journal     Full-text available via subscription   (Followers: 1)
Scientia Marina     Open Access   (Followers: 1)
Western Indian Ocean Journal of Marine Science     Open Access   (Followers: 1)
Asian Journal of Fisheries and Aquatic Research     Open Access  
Thalassas : An International Journal of Marine Sciences     Hybrid Journal  
Oceans     Open Access  
Aquatic Research     Open Access  
Jurnal Kelautan Tropis     Open Access  
Acta Aquatica : Aquatic Sciences Journal     Open Access  
Depik Jurnal Ilmu-Ilmu Perairan, Pesisir dan Perikanan     Open Access  
Journal of Agricultural and Marine Sciences     Open Access  
Turkish Journal of Maritime and Marine Sciences     Open Access  
Arquivos de Ciências do Mar     Open Access  
Scientific Drilling     Open Access  
Jurnal Kelautan : Indonesian Journal of Marine Science and Technology     Open Access  
Oceanologia     Open Access  
Revista de Gestão Costeira Integrada     Open Access  
Revista Ciencias Marinas y Costeras     Open Access  
Egyptian Journal of Aquatic Research     Open Access  
China Ocean Engineering     Hybrid Journal  
Revista de Biología Marina y Oceanografía     Open Access  
Latin American Journal of Aquatic Research     Open Access  
Acta Oceanologica Sinica     Hybrid Journal  
Similar Journals
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Journal of Marine Science and Engineering
Number of Followers: 4  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2077-1312
Published by MDPI Homepage  [246 journals]
  • JMSE, Vol. 10, Pages 1831: A Robust Method to Automatically Detect Fin
           Whale Acoustic Presence in Large and Diverse Passive Acoustic Datasets

    • Authors: Elena Schall, Clea Parcerisas
      First page: 1831
      Abstract: The growing availability of long-term and large-scale passive acoustic recordings open the possibility of monitoring the vocal activity of elusive oceanic species, such as fin whales (Balaenoptera physalus), in order to acquire knowledge on their distribution, behavior, population structure and abundance. Fin whales produce low-frequency and high-intensity pulses, both as single vocalizations and as song sequences (only males) which can be detected over large distances. Numerous distant fin whales producing these pulses generate a so-called chorus, by spectrally and temporally overlapping single vocalizations. Both fin whale pulses and fin whale chorus provide a distinct source of information on fin whales present at different distances to the recording location. The manual review of vast amounts of passive acoustic data for the presence of single vocalizations and chorus by human experts is, however, time-consuming, often suffers from low reproducibility and in its entirety, it is practically impossible. In this publication, we present and compare robust algorithms for the automatic detection of fin whale choruses and pulses which yield good performance results (i.e., false positive rates < 3% and true positive rates > 76%) when applied to real-world passive acoustic datasets characterized by vast amounts of data, with only a small proportion of the data containing the target sounds, and diverse soundscapes from the Southern Ocean.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-29
      DOI: 10.3390/jmse10121831
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1832: Experimental Investigation on Vibro-Acoustic
           Characteristics of Stiffened Plate Structures with Different Welding
           Parameters

    • Authors: Ziheng Chen, Xiaodan Jia, Yongshui Lin, Huabing Liu, Weiguo Wu
      First page: 1832
      Abstract: Varied welding process parameters result in different welding energy inputs and welding residual stresses, significantly impacting the vibro-acoustic characteristics. This work investigated the influence of different welding energy inputs on the vibro-acoustic characteristics of the stiffened plate structure. Several experiments on the stiffened plate structure with different welding energy inputs were conducted regarding modal, underwater vibration, and acoustic radiation. The results revealed that welding energy input had the most significant impact on the first-order natural frequency, and the impact first becomes higher and subsequently decreases as welding energy input increases. The welding energy input had relatively little effect on the peak point distribution of vibration and acoustic radiation curves but could affect the peak point amplitude. With the increase in welding energy input, the overall vibration acceleration level and sound radiation level in each frequency band decreased and then increased. The best result was obtained when the welding energy input was 167 J/cm with a welding current of 200 A, a welding voltage of 25 V, and a welding speed of 3.02–3.06 mm/s. Based on construction technology, this research can provide some instructive insights for enhancing the acoustic stealth performance of ships and marine structures.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-29
      DOI: 10.3390/jmse10121832
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1833: Laboratory Observations of Swash Signatures
           Using Video Imagery

    • Authors: Haoye Yang, Chi Zhang, Jian Shi, Xiangming Cao, Yuan Li
      First page: 1833
      Abstract: Swash motions are important for the design and assessment of beach protection projects, while the limitation of insightful observations in the swash zone still exists. An automatic identification method based on video imagery is developed to monitor and extract instantaneous swash motions in the laboratory. The method increases video sampling frequency and improves image enhancement in identification. The improved method fits well with the results of the manual method. The incident band roll-off of the swash spectrum in the experiment is consistent with those observed on natural beaches. Results have shown that on the barred beach, water depths influence the peak frequency in the incident band and cause a multi-peak swash spectrum. A large incident wave period causes a low peak frequency but high peak energy in the swash spectrum. Large incident wave height results in wider energy coupling, making swash to be saturated and more energy in swash energy. The existence of a barred beach promotes swash energy transferring from a high frequency to a low frequency.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-29
      DOI: 10.3390/jmse10121833
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1834: An Analytical Symplectic Method for Buckling of
           Ring-Stiffened Graphene Platelet-Reinforced Composite Cylindrical Shells
           Subjected to Hydrostatic Pressure

    • Authors: Zhanzhong Sun, Gangyi Hu, Xueyang Nie, Jiabin Sun
      First page: 1834
      Abstract: In this paper, a novel analytical approach for the buckling of ring-stiffened porous graphene platelet-reinforced composite cylindrical shells under hydrostatic pressure is proposed under the framework of symplectic mechanics. Three types of graphene platelet-reinforced patterns and porosity distributions are considered, and the effective material properties of porous graphene platelet-reinforced composite are determined with a modified Halpin–Tsai model. In the symplectic approach, the governing equations in the conventional Lagrangian system are transformed into a set of Hamiltonian canonical equations, and therefore, the buckling analysis is reduced into an eigenproblem in a symplectic space. Consequently, the accurate critical pressures and corresponding analytical buckling mode shapes are obtained simultaneously without any trial function. The numerical results are compared with the existing results, and good agreements are observed. A comprehensive parametric study of the geometrical parameters, boundary conditions, material properties, and ring-stiffener parameters on the buckling behavior of such shells is also presented.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-29
      DOI: 10.3390/jmse10121834
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1835: Speed Optimization of Container Ship
           Considering Route Segmentation and Weather Data Loading: Turning
           Point-Time Segmentation Method

    • Authors: Xiaohe Li, Baozhi Sun, Jianhai Jin, Jun Ding
      First page: 1835
      Abstract: As one of the ship energy efficiency optimization measures with the most energy saving and emission reduction potential, ship speed optimization has been recommended by the International Maritime Organization. In ship speed optimization, considering the influence of weather conditions, route segmentation and weather data loading methods significantly affect the reliability of speed optimization results. Therefore, taking the ocean-going container ship as the research object, on the basis of constructing the main engine fuel consumption prediction model and shaft speed prediction model based on machine learning methods, a route segmentation and weather loading-speed optimization iterative algorithm is proposed in this study. Single-objective speed optimization research is then conducted based on the algorithm. The research results show that the proposed algorithm effectively reduces the difference between optimized fuel consumption and actual fuel consumption, and can achieve a fuel-saving rate between 2.1% and 5.2%. This study achieves an accurate and reliable prediction of ship fuel consumption and shaft speed, and solves the strong coupling problem between route segmentation, weather loading, and speed optimization by iterative optimization of ship speed. The proposed algorithm provides strong technical support for ships to achieve the goal of energy saving and emission reduction.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-29
      DOI: 10.3390/jmse10121835
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1836: SAR Observation of Waves under Ice in the
           Marginal Ice Zone

    • Authors: Ziyue Dai, Huimin Li, Dongbo Liu, Chen Wang, Lijian Shi, Yijun He
      First page: 1836
      Abstract: The marginal ice zone (MIZ) connects the open ocean and the pack ice, playing significant roles in shaping the ice edge and wave–ice interaction. Spaceborne synthetic aperture radar (SAR) has been demonstrated to be one of the most advantageous sensors for MIZ exploration given its capability to collect images under all weather conditions during day and night. In this study, we take advantage of the Sentinel-1 wave mode vignettes acquired around the Antarctic to quantify the image properties over MIZ. A data set of SAR images covering the ice edge with both open water and sea ice present in the same scene was created by manual inspection. It is found that the radar return over sea ice decreases by an average of approximately 1.78 dB in comparison to its adjacent open water, which is roughly independent of the polarizations and incidence angles. The long ocean waves are barely attenuated right across the ice edge in terms of their comparable azimuth cutoff. Further inside the ice from the edge, the waves are gradually dampened out at distances associated with their wavelengths. The results obtained in this study shall help interpret the radar scattering model validation as well as the wave–ice interaction.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-29
      DOI: 10.3390/jmse10121836
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1837: The Role of Microplastics in Marine Pathogen
           Transmission: Retrospective Regression Analysis, Experimental Design, and
           Disease Modelling

    • Authors: Gorka Bidegain, Marta Sestelo, Patricia L. Luque, Ibon Uriarte, Arantza Iriarte, Fernando Villate
      First page: 1837
      Abstract: Marine wildlife and aquaculture species can accumulate large amounts of marine microplastic debris (MMD) (<1 mm) carrying pathogens, thus threatening the health of marine ecosystems and posing a risk to food safety and human health. Here, we outline a theoretical three-perspective approach for studying the relationship between MMD and disease. First, we provide a framework for retrospective analysis of MMD and pathogen loads in marine animal tissues to assess the relationship between these and other environmental variables in order to decide whether a compound or pathogen should be considered an emerging substance or organism. Second, we describe an experimental design for testing the effects of a variety of microplastics on infection intensity in two model species (oysters and zebrafish). Finally, we create a theoretical susceptible–infected microplastic particle and pathogen transmission model for bivalves and fish. Overall, the experiments and models we propose will pave the way for future research designed to assess the role of MMD as a vector for marine and human pathogens. This multi-faceted approach needs to be an urgent priority of the EU Strategic Research Innovation Agenda for addressing marine disease challenges related to MMD.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-30
      DOI: 10.3390/jmse10121837
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1838: Feasibility Analysis of the Effects of Scrubber
           Installation on Ships

    • Authors: Çağlar Karatuğ, Yasin Arslanoğlu, C. Guedes Soares
      First page: 1838
      Abstract: A feasibility analysis was conducted on a crude oil tanker. Differences in power generation and fuel consumption of the diesel generators based on the noon report of the specified marine vessel were analyzed for similar periods before and after the scrubber application. Accordingly, the changes in releasing amounts of emissions were calculated. Then, a financial evaluation was realized with three economic indicators. As a result of the analysis performed, it is found that the power generation and fuel consumption realized by each diesel generator are increased after scrubber application. Nevertheless, its implementation on board may be considered acceptable in light of the economic findings. However, it has been determined that scrubber implementation causes an increase in all pollutants’ amounts except SOX. Therefore, it contradicts the zero-emission ship target and decarbonization strategy stated by IMO.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-11-30
      DOI: 10.3390/jmse10121838
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1839: Multi-Branch Gated Fusion Network: A Method
           That Provides Higher-Quality Images for the USV Perception System in
           Maritime Hazy Condition

    • Authors: Yunsheng Fan, Longhui Niu, Ting Liu
      First page: 1839
      Abstract: Image data acquired by unmanned surface vehicle (USV) perception systems in hazy situations is characterized by low resolution and low contrast, which can seriously affect subsequent high-level vision tasks. To obtain high-definition images under maritime hazy conditions, an end-to-end multi-branch gated fusion network (MGFNet) is proposed. Firstly, residual channel attention, residual pixel attention, and residual spatial attention modules are applied in different branch networks. These attention modules are used to focus on high-frequency image details, thick haze area information, and contrast enhancement, respectively. In addition, the gated fusion subnetworks are proposed to output the importance weight map corresponding to each branch, and the feature maps of three different branches are linearly fused with the importance weight map to help obtain the haze-free image. Then, the network structure is evaluated based on the comparison with pertinent state-of-the-art methods using artificial and actual datasets. The experimental results demonstrate that the proposed network is superior to other previous state-of-the-art methods in the PSNR and SSIM and has a better visual effect in qualitative image comparison. Finally, the network is further applied to the hazy sea–skyline detection task, and advanced results are still achieved.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121839
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1840: The Influence of Spatial and Temporal Scales on
           Fisheries Modeling—An Example of Sthenoteuthis oualaniensis in the
           Nansha Islands, South China Sea

    • Authors: Xingxing Zhou, Shengwei Ma, Yancong Cai, Jie Yu, Zuozhi Chen, Jiangtao Fan
      First page: 1840
      Abstract: The choice of spatial and temporal scales affects the performance of fisheries models and is particularly important in exploring the relationship between resource abundance and the marine environment. Traditional fishery models are constructed at a particular scale, and the results of the study hold only at that scale. Sthenoteuthis oualaniensis is one of the main target species of large-scale light falling-net fishing in the Nansha Islands in the South China Sea. We used the S. oualaniensis fishery in the Nansha Islands as an example to compare the performance of fisheries models for 12 spatial and temporal settings and to explore the relationship between the abundance of S. oualaniensis and the marine environment in the Nansha Islands under the optimal spatial and temporal settings. The results show that the spatial and temporal scale chosen in the construction of the fishery model is not as fine as possible in generalized additive models (GAMs) for abundance index-catch per unit effort (AI-CPUE)-based scenarios, and 0.5° with the season was the best spatial and temporal setting; meanwhile, in GAMs for AI-effort-based scenarios, 0.1° with the month was the best spatial and temporal setting. The distribution of S. oualaniensis resources in the Nansha Islands was characterized by significant seasonal variation, and the monthly center of gravity had a significant negative correlation with the Niño 3.4 index and the PDO index, with correlation coefficients of 100 and 1000, respectively. It is hypothesized that Pacific Decadal Oscillation and ENSO events affect the marine environment in the South China Sea by influencing the strength of the Kuroshio force and the degree of Kuroshio curvature, which in turn affects the distribution of S. oualaniensis in the Nansha Islands. The results help us to understand the influence of spatial and temporal scales on fisheries models and the environmental factors affecting the distribution of S. oualaniensis resources in the Nansha Islands. Thus, they provide a scientific basis for the sustainable development of S. oualaniensis fisheries in this region.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121840
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1841: Underwater Image Classification Algorithm Based
           on Convolutional Neural Network and Optimized Extreme Learning Machine

    • Authors: Junyi Yang, Mudan Cai, Xingfan Yang, Zhiyu Zhou
      First page: 1841
      Abstract: In order to deal with the target recognition in the complex underwater environment, we carried out experimental research. This includes filtering noise in the feature extraction stage of underwater images rich in noise, or with complex backgrounds, and improving the accuracy of target classification in the recognition process. This paper discusses our contribution to improving the accuracy of underwater target classification. This paper proposes an underwater target classification algorithm based on the improved flow direction algorithm (FDA) and search agent strategy, which can simultaneously optimize the weight parameters, bias parameters, and super parameters of the extreme learning machine (ELM). As a new underwater target classifier, it replaces the full connection layer in the traditional classification network to build a classification network. In the first stage of the network, the DenseNet201 network pre-trained by ImageNet is used to extract features and reduce dimensions of underwater images. In the second stage, the optimized ELM classifier is trained and predicted. In order to weaken the uncertainty caused by the random input weight and offset of the introduced ELM, the fuzzy logic, chaos initialization, and multi population strategy-based flow direction algorithm (FCMFDA) is used to adjust the input weight and offset of the ELM and optimize the super parameters with the search agent strategy at the same time. We tested and verified the FCMFDA-ELM classifier on Fish4Knowledge and underwater robot professional competition 2018 (URPC 2018) datasets, and achieved 99.4% and 97.5% accuracy, respectively. The experimental analysis shows that the FCMFDA-ELM underwater image classifier proposed in this paper has a greater improvement in classification accuracy, stronger stability, and faster convergence. Finally, it can be embedded in the recognition process of underwater targets to improve the recognition performance and efficiency.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121841
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1842: Numerical Investigation on the Dynamics of
           Mixture Transport in Flexible Risers during Deep-Sea Mining

    • Authors: Lei Liu, Kangyu Gai, Jianmin Yang, Xiaoxian Guo
      First page: 1842
      Abstract: Mixture transport from a seabed mining vehicle to a buffer is a key procedure in deep-sea mining. Dynamic performances of the particle–seawater mixture in a single-peak flexible riser were numerically investigated using computational fluid dynamics and the discrete element method. Both the time-averaged local characteristics and the instantaneous flow behaviors in the riser are presented. The effects of key parameters, such as feeding concentration and mixture transport velocity, were evaluated by a sensitivity analysis. Large local concentration accompanied by small particle velocity occurs in the ascending sections and increases the risk of blockage. The particle–wall contact reaches the maximum value at both the peak and trough of the single-peak riser. A small feeding concentration would reduce both particle–wall contact, and hydraulic gradient, whereas a moderate mixture transport velocity may be appropriate for the transport in terms of operation safety and energy efficiency. In addition, the mixture transport in a double-peak riser was simulated to examine which configuration is better for engineering applications. The lower maximum local concentration, particle–wall contact and hydraulic gradient and the larger minimum particle velocity indicate that a double-peak flexible riser may be more suitable for the mixture transport.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121842
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1843: Evidence of Genetic Segregation among Meagre
           (Argyrosomus regius) Atlantic Spawning Areas

    • Authors: Rita Almeida, Catarina S. Mateus, Maria Judite Alves, João P. Marques, Joana Pereira, Nuno Prista, Henrique Cabral, Pedro R. Almeida, Bernardo R. Quintella
      First page: 1843
      Abstract: The meagre Argyrosomus regius, one of the largest sciaenidae in the world, is a valuable resource for fisheries and aquaculture. Despite its socioeconomic relevance, knowledge about population dynamics and wild stocks is still scarce, and conservation risks are associated with overexploitation. Two genetic distinct groups, one in the North Atlantic Ocean and one in the eastern Mediterranean Sea, were identified by previous studies. However, little is known about the genetic structure of the Atlantic group, where four important spawning areas have been identified. To assess if each spawning area is an independent breeding unit, the genetic diversity, populational structure, and demographic history of A. regius along the North–East and Eastern Central Atlantic coast were analyzed, using 15 microsatellite loci. Results corroborate the hypothesis tested, suggesting four genetic groups: a first group encompassing individuals from the Gironde spawning area, a second group encompassing individuals from the Tagus spawning area, a third group corresponding to individuals captured in the Algarve region, and a forth group gathering individuals from Morocco and Mauritania. This study reveals the need for specific fisheries management plans considering genetic structure information, and highlights the need for international cooperation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121843
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1844: Development of Discrete-Time Waterjet Control
           Systems Used in Surface Vehicle Thrust Vectoring

    • Authors: Eleftherios K. Loghis, Nikolaos I. Xiros
      First page: 1844
      Abstract: To create an autonomous surface vehicle, the microcontroller that will be responsible for the vessel’ s response will have access to both engine thrust controls and steering controls. In the case of a vehicle with waterjet propulsion, the term “controls” refers to engine RPM and nozzle angle. The latter allows the thrust vectoring. Having performed the mathematical modelling of the surface vessel, a method must be found such that the microcontroller actions on the controls create the desired outputs, based on predefined performance objectives. A commonly selected control algorithm considered an industry standard for control applications—at least from the perspective of classical control methods—is the PID control scheme. Many times, a PID control scheme is sufficient for achieving the required performance. There are also many methods that extend the functionality of the PID to robust control schemes, to accomplish more specific targets, such as noise rejection. The vast majority of all these implementations, will have to be implemented using a digital microcontroller or an FPGA. This paper assists theoretically in implementing PID controllers digitally, by elaborating on the discrete-time perspective of PID control. It also provides a test method for evaluating the algorithmic implementation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121844
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1845: Finite Time Trajectory Tracking with Full-State
           Feedback of Underactuated Unmanned Surface Vessel Based on Nonsingular
           Fast Terminal Sliding Mode

    • Authors: Donghao Xu, Zipeng Liu, Jiuzhen Song, Xueqian Zhou
      First page: 1845
      Abstract: Marine transportation and operations have attracted the attention of more and more countries and scholars in recent years. A full-state finite time feedback control scheme is designed for the model parameters uncertainty, unknown ocean environment disturbances, and unmeasured system states in the underactuated Unmanned Surface Vessel (USV) trajectory tracking control. The external wind, wave and current environmental disturbances and model parameters perturbation are extended by Nonlinear Extended State Observer (NESO) to the state of the system, namely complex disturbances. The complex disturbances, positions and velocities of USV can be observed by NESO and feedback to USV control system. Next, the underactuated USV error model is obtained by operating the obtained feedback information and the virtual ship model. According to the error model, a Nonsingular Fast Terminal Sliding Model surface (NFTSM) is constructed to realize finite-time control. The control law is deduced through the Lyapunov stability theory to ensure the stability of the system. The results of MATLAB numerical simulations under different disturbances show that the trajectory tracking algorithm has fast responses, and a good convergence of the errors is observed, which verifies the effectiveness of the designed scheme.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121845
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1846: Biogeochemical Role of Algae in Aquatic
           Ecosystems: Basic Research and Applied Biotechnology

    • Authors: Nikolay V. Lobus
      First page: 1846
      Abstract: The term “algae” has no formal taxonomic position [...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121846
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1847: Research on PID Parameter Tuning and
           Optimization Based on SAC-Auto for USV Path Following

    • Authors: Lifei Song, Chuanyi Xu, Le Hao, Jianxi Yao, Rong Guo
      First page: 1847
      Abstract: Unmanned surface vessels (USVs) are required to follow a path during a task. This is essential for the USV, especially when following a curvilinear path or considering the interference of waves, and this work has been proven to be complicated. In this paper, a PID parameter tuning and optimizing method based on deep reinforcement learning were proposed to control the USV heading. Firstly, the Abkowite dynamics model with three degrees of freedom (DOF) is established. Secondly, the guidance law on the line-of-sight (LOS) method and the USV heading control system of the PID controller are designed. To satisfy the time-varying demand of PID parameters for guiding control, especially when the USV moves in waves, the soft actor–critic auto (SAC-auto) method is presented to adjust the PID parameters automatically. Thirdly, the state, action, and reward functions of the agent are designed for training and learning. Finally, numerical simulations are performed, and the results validated the feasibility and validity of the feasibility and effectiveness of the proposed method.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121847
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1848: Regional Differences and Dynamic Changes in Sea
           Use Efficiency in China

    • Authors: Qian Zhang, Xuan Yu
      First page: 1848
      Abstract: This study aims to identify the overall level of China’s sea use efficiency (SUE) from 2006 to 2018 as well as regional differences and dynamic changes The super-efficiency weighted slacks-based measure (Super-WSBM) model and the global Malmquist–Luenberger (GML) index are employed. Results indicate that the SUE is at a medium-efficiency level. The inspection period revealed a decline period (2006–2008), a steady increase period (2008–2013), and a rapid increase period (2013–2018), exhibiting a “checkmark” type of growth. SUE has significant regional differences, and the degree of polarization has increased. Shanghai, Guangdong, and Shandong are high-efficiency regions, but unlike Shandong, which has experienced a rapid growth, the SUE of Shanghai and Guangdong has declined to varying degree, in Shanghai being particularly significant; Jiangsu and Tianjin are medium-efficiency regions, and SUE has experienced a rapid growth; Fujian, Hebei, and Zhejiang are inferior-efficiency regions, and SUE has slightly increased; Liaoning, Hainan, and Guangxi are low-efficiency regions. Except for a slight decline in Hainan, Liaoning and Guangxi experienced small increases. Thus, a sea use policy must be formulated on the basis of local conditions to promote the coordinated development of the marine economy. Moreover, the negative external impact of sea use on the marine environment must be observed, and marine resources within the range of the sea must be utilized.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121848
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1849: New Insights about Upwelling Trends off the
           Portuguese Coast: An ERA5 Dataset Analysis

    • Authors: Spallou Ferreira, Magda Sousa, Ana Picado, Nuno Vaz, João Miguel Dias
      First page: 1849
      Abstract: In recent decades, several studies have highlighted the importance of the temporal and spatial structure of upwelling in defining the high levels of productivity of coastal upwelling systems. This work intends to assess the temporal and spatial trends of upwelling along the west and south Portuguese coasts from 1979 to 2020, comparing the patterns between these regions. Two different methodologies to calculate the upwelling indexes (UI), based on wind and sea surface temperature (SST) data, were applied to relate the wind-induced upwelling-favourable conditions (UIET) with the expected response on superficial waters, as indicated by the SST patterns (UISST). The upwelling-favourable conditions are quite consistent and more frequent and intense on the west coast than on the south coast. Spatially, it was verified from the UIET that upwelling-favourable conditions are more intense in association with the main west coast capes and that there is an intensification of favourable winds towards Cape São Vicente, both on the west and south coasts. Seasonally, upwelling-favourable UIET was found to be more consistent in the summer on both coasts. However, it also exists in the winter months. In terms of interannual variations, it should be highlighted that between 1992 and 2005 more intense favourable conditions and an apparent change in the seasonality after 2015 were found. Although some of the results derived from the UIET are corroborated by the UISST (namely, the main spatial trends and interannual variations in the upwelling intensity), several uncertainties are associated with the last index that interfere with its interpretation. For future works, it is advisable to develop a more robust SST-based index that can circumvent the uncertainties pointed out in the present study.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121849
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1850: The Impact of Marine Engine Component Failures
           upon an Explosion in the Starting Air Manifold

    • Authors: Leszek Chybowski, Daniel Wiaterek, Andrzej Jakubowski
      First page: 1850
      Abstract: Based on available sources, the frequency of explosions in the marine engine’s starting air manifolds is determined under real conditions. A cause-and-effect analysis of these explosions and their root causes are identified. A probabilistic model of an explosion in the starting air manifold of a marine engine is built using a fault tree analysis (FTA). Using a stochastic simulation (Monte Carlo) and an exact reliability availability calculation (ERAC) algorithm applied to the developed FTA model, selected reliability measures are calculated to describe an incident of the top event, which involves an explosion in the starting air manifold. For such an event, several factors are calculated, including the availability, the unavailability, the failure frequency, and the mean time to failure. Based on the simulations, the relative frequency of the top event is determined in relation to the number of events that can simultaneously occur and lead to an explosion. The significance of each basic event is assessed to determine their individual impact on the explosion incident. The following measures are used: the Vesely–Fussell measure of importance, the criticality measure of importance, the Birnbaum measure of reliability importance, and the Birnbaum measure of structural importance. The results of the analysis show that defective starting air valves are most responsible for the explosion incident in the starting air manifold. During the first year of the ship’s operation, the reliability does not fall below the value of 0.65, while the mean time to failure and the top event frequency are statistically at the level of one explosion per approximately 2.28 years of continuous engine operation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121850
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1851: Fast High-Precision Bisection Feedback Search
           Algorithm and Its Application in Flattening the NURBS Curve

    • Authors: Kaige Zhu, Guoyou Shi, Jiao Liu, Jiahui Shi
      First page: 1851
      Abstract: It is important to accurately calculate flattening points when reconstructing ship hull models, which require fast and high-precision computation. However, some search algorithms, such as the bisection method, iterate near the optimal value too many times before converging in high-precision computation. The paper proposes a fast high-precision bisection feedback search (FHP-BFS) algorithm to solve the problem. In the FHP-BFS algorithm, the Newton–Raphson (NR) method is adopted to accelerate the convergence speed by considering the iteration characteristics of subintervals. Furthermore, a new feedback mechanism is proposed to control the feedback directions. In addition, an acceleration algorithm, called the interval reformation method, is used to guide the FHP-BFS algorithm for fast convergence. Finally, the flattening algorithm is improved by the FHP-BFS algorithm. In the comparative experiments, the practical efficacy of the FHP-BFS algorithm is first demonstrated, and then the optimal range of the threshold precision is determined. Next the FHP-BFS algorithm is compared to the best existing algorithms. Finally, the performance of the improved flattening algorithm is verified. The experiments demonstrate that the FHP-BFS algorithm has optimal performance among the compared algorithms, and it has an improved computation efficiency while maintaining robustness. The improved flattening algorithm reduces the computation time, ensures smoothness and meets practical engineering requirements.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121851
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1852: Research on The Chloride Diffusion Modified
           Model for Marine Concretes with Nanoparticles under The Action of Multiple
           Environmental Factors

    • Authors: Zhengyi Lv, Maohua Zhang, Yanyu Sun
      First page: 1852
      Abstract: Marine concrete structures are subject to the action of multiple environments during their service time. This leads to increased deterioration in the durability of marine concretes under the combined action of bending load and dry–wet cycles, salt freeze–thaw cycles, and salt spray erosion. The main reason for the damage of concrete under the action of the above three environments is Cl- attack. The free Cl- content (Cl-f) and the free Cl- diffusion coefficient (Df) of concrete can explain the diffusion of Cl- in concrete. This paper considers the actual environment of marine concrete structures and develops the Cl- diffusion modified model for nano-marine concretes under the action of dry–wet cycles, salt freeze–thaw cycles, and bending load and salt spray erosion. The nano-SiO2, nano-Fe2O3, and nano-Fe3O4 were firstly incorporated into ordinary marine concrete, then the Cl- content of each group of marine concrete was measured at different depths, and the Cl- diffusion coefficients were calculated; finally, the Cl- diffusion modified model was established under different environmental factors. The test results show that the total and free Cl- diffusion coefficients of nano-marine concretes were lower than those of ordinary marine concrete, and the nano-SiO2, nano-Fe2O3, and nano-Fe3O4 of the optimum dosage were 2%, 1%, and 2%, respectively. The fitting results of Cl- content have a good correlation, and the correlation coefficient (R) is basically above 0.98.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121852
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1853: Optimization of Shear Bonds of the Grouted
           Joints of Offshore Wind Turbine Tower Based on Plastic Damage Model

    • Authors: Linqing Zhou, Weiyuan Sun, Yu Cao, Chaonan He, Xinwei Ma
      First page: 1853
      Abstract: In recent years, offshore wind power has been developing rapidly, and single piles are among the commonly used foundations for wind turbines. Presently, experimental studies of the grouted connections of pile foundations are limited to the study of scaler models. Numerical simulations are more suitable for the mechanical analysis of the full-size structure instead of experimental ones. In numerical simulations, the linear elasticity model is widely adopted, but the plastic damage is studied scarcely. So, shear bond parameter research concerning grouted joints needs to be supplemented. In this paper, a bilinear random-motion reinforcement model based on the classical metal plasticity theory is adopted for steel, and the model for the grouting material is based on the Sidiroff energy equivalence principle. The plastic damage model for the grouted connecting section is established; the stresses and deformation distribution of the steel pipes and grout in the connecting section are analyzed using the changed shear bond parameters. The results show that the rectangular and triangular shear bonds are more reasonable than the semicircular shear bond transfer. Increasing the height of the shear bond may reduce the maximum stress and the maximum vertical displacement of the grout, and the shear bond width change has less influence on the joint bond stress and displacement.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121853
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1854: An Econometric Analysis of Sea Surface
           

    • Authors: Alok Bhargava, Juan A. Echenique
      First page: 1854
      Abstract: This paper analyzed quarterly longitudinal data for 64,800 1 × 1 degree grids during 2000–2019 on sea surface temperatures, sea ice concentrations, and ocean surface current zonal and meridional velocities in the Northern and Southern hemispheres. The methodological framework addressed the processing of remote sensing signals, interdependence between sea surface temperatures and sea ice concentrations, and combining zonal and meridional velocities as the eddy kinetic energy. Dynamic and static random effects models were estimated by maximum likelihood and stepwise methods, respectively, taking into account the unobserved heterogeneity across grids. The main findings were that quarterly sea surface temperatures increased steadily in the Northern hemisphere, whereas cyclical patterns were apparent in Southern hemisphere; sea ice concentrations declined in both hemispheres. Second, sea surface temperatures were estimated with large negative coefficients in the models for sea ice concentrations for the hemispheres; previous sea ice concentrations were negatively associated with sea surface temperatures, indicating feedback loops. Third, sea surface temperatures were positively and significantly associated with eddy kinetic energy in Northern hemisphere. Overall, the results indicated the importance of reducing sea surface temperatures via reductions in greenhouse gas emissions and the dumping of pollutants into oceans for maintaining sea ice concentrations and enhancing global sustainability.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-01
      DOI: 10.3390/jmse10121854
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1855: Fault-Tree-Analysis-Based Health Monitoring for
           Autonomous Underwater Vehicle

    • Authors: Sungil Byun, Mayorkinos Papaelias, Fausto Pedro García Márquez, Dongik Lee
      First page: 1855
      Abstract: Undersea terrain and resource exploration missions using autonomous underwater vehicles (AUVs) require a great deal of time. Therefore, it is necessary to monitor the state of the AUV in real time during the mission. In this paper, we propose an online health-monitoring method for AUVs using fault-tree analysis. The entire system is divided into four subsystems. Fault trees of each subsystem are designed based on the information of performance and reliability. Using the given subsystem fault trees, the health status of the entire system is evaluated by considering the performance, reliability, fault status, and weight factors of the parts. The effectiveness of the proposed method is demonstrated through simulations with various scenarios.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121855
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1856: A Review of Ship-to-Ship Interactions in Calm
           Waters

    • Authors: Claire DeMarco Muscat-Fenech, Tonio Sant, Vito Vasilis Zheku, Diego Villa, Michele Martelli
      First page: 1856
      Abstract: The hydrodynamic interaction between two or more ships in harbours or inland waterways is a classical maritime engineering research area. In ship manoeuvring practice, ship masters try to determine the speed and gap limit when a ship is passing or encountering others, particularly in confined water ways. This requires an accurate prediction of the interaction force acting on both ships. The pioneer experimental studies showed that the interaction could lead to a very large yaw moment and this moment is strongly time-dependent, which could make the ships veer from their original courses, leading to collisions. Based on the findings on experimental measurements, some empirical formulas are proposed in the literature to predict such interaction forces. However, these formulas could provide a satisfactory estimation only when the ship speed is quite high, and the water depth is shallow and constant. Numerical simulation overcomes this issue by simulating the ship-to-ship problem by considering the effect of the 3D ship hull, variable water depth and ship speed. Numerical simulation has now become the most widely adopted method to investigate the ship-to-ship problem. In the present study, the development of the methodologies of ship-to-ship problems will be reviewed, and the research gap and challenges will be summarized.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121856
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1857: Effects of Acute High-Temperature Stress on
           Physical Responses of Yellowfin Tuna (Thunnus albacares)

    • Authors: Hongyan Liu, Zhengyi Fu, Gang Yu, Zhenhua Ma, Humin Zong
      First page: 1857
      Abstract: To understand the physiological reactions of juvenile yellowfin tuna (Thunnus albacares) under acute high-temperature stress, this study measured the changes in biochemical indexes of serum, liver, gill, and muscle of yellowfin tuna under acute high-temperature stress (HT, 34 °C) and a control group (28 °C) for 0 h and 6 h, 24 h and 48 h. The rising speed of water temperature in the HT group was 2 °C/h and the timing started when the temperature reached 34 °C. In the HT group, there was no significant difference between the four adjacent times in cortisol and lactic acid concentration. Serum triglyceride, cholesterol, and alkaline phosphatase concentration were significantly different from the four adjacent times. The superoxide dismutase (SOD) activity in the liver and gills increased at 6 h and 24 h, and the gills and liver had antioxidant reactions in a short time. The malondialdehyde (MDA) concentration in the gills changed significantly at 6 h, while that in the liver did not change significantly. The gills were more sensitive to temperature stress than the liver and muscle. Acute high-temperature stress affected yellowfin tuna’s antioxidant enzymes and metabolic indexes, resulting negative trend in physiological indexes, indicating that yellowfin tuna juveniles are susceptible to elevated temperature.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121857
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1858: Modeling of Thermodynamic Consolidation of Sea
           Ice Ridges Drifting in the Water with Changing Temperature

    • Authors: Aleksey Marchenko
      First page: 1858
      Abstract: Oceanographic and ice conditions in the region of Spitsbergen Bank in the Barents Sea were investigated in research cruises of the “Polarsyssel” in 2017–2019. Trajectories of ice drift were constructed using GPS data of the buoys deployed on the floes in the research cruises. The duration of the ice season in the region was analyzed using ice charts. The air temperature and wind velocities were analyzed using the data of meteorological stations on Bear Island and Hopen Island. Fieldwork on drifting ice showed the existence of thick consolidated floes with drafts up to 8 m, which were identified as completely consolidated sea ice ridges. The presence of such floes is dangerous for winter navigation along Spitsbergen Bank. A model of thermodynamic consolidation of ice ridges was formulated to investigate the thermodynamic evolution of ice ridges. The observed air and sea water temperatures were used in the boundary conditions on top and bottom surfaces of sea ice rubble. It was shown that the regular interaction of sea ice rubble with Atlantic and Arctic waters in the region of Spitsbergen Bank leads to almost complete consolidation of the ice rubble with an initial macro-porosity 0.2 for 150 days.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121858
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1859: Influence of Sea Surface Temperature in the
           Tropics on the Antarctic Sea Ice during Global Warming

    • Authors: Genrikh Alekseev, Anastasiia Vyazilova, Alexander Smirnov
      First page: 1859
      Abstract: Sea ice extent in the Antarctica, unlike in the Arctic, did not show a decrease until 2016 under observed global warming. The aim of the study is to explain this climatic phenomenon based on the idea of joint dynamics of the Southern Ocean oceanic structures—the Antarctic polar front, the boundary of the maximum sea ice extent and atmospheric structures—Intratropical Convection Zone (ITCZ) and the Hadley circulation. ERA5 reanalysis and HadISST data were used as well as the sea ice database for the period 1979–2021. The effect of SST at low latitudes of the North Atlantic on the position of the Antarctic polar front and the maximum sea ice extent has been established. The SST in the same area of the North Atlantic has an opposite effect on the sea ice extent in the Arctic. The impact of the SST on the sea ice is mediated through the ITCZ and the Hadley circulation. The obtained results confirmed the key role of the SST at the low latitudes of the North Atlantic in the development of multidirectional trends in changes in the Arctic and the Antarctic ice cover in 1979–2016.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121859
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1860: Growth and Physiological Responses of
           

    • Authors: Li Zhou, Peng Xiao, Baoning Liu, Jichang Han, Yahe Li, Chengxu Zhou
      First page: 1860
      Abstract: The growth and physiological process of microalgae interact with environmental nutrients. In the present study, we compared the growth and physiological characteristics of coccolithophore Chrysotila roscoffensis under the effects of phosphate at high and low concentrations, and of organic phosphorus of adenosine triphosphate (ATP) and Na2-glycerophosphate (SG). The growth, photosynthesis, calcification, alkaline phosphatase activity, and inorganic nutrient absorption rate were comparatively studied. The results showed that the culture with a low concentration of initial phosphate (6 μM) had a lower growth rate than that with a high concentration (45 μM). However, a relatively similar maximum cell density could be achieved. Equimolar inorganic phosphorus supported a higher initial growth rate than organic phosphorus. ATP was better than SG at supporting higher growth rates, higher photosynthetic activity, and higher cell density. Cellular alkaline phosphatase (AP) responded rapidly to nutrient variations with sharp changes of activities, independent of the initial P resources. Cellular calcification was at a higher level in groups with lower growth rates. Phosphate in low concentration in the medium was not absorbed during the early growth period while that in high concentration was rapidly absorbed. Instead, phosphate in low concentration was rapidly absorbed in the late stationary phase. The absorption of nitrate was affected by the initial P resources as well. The DIN/DIP ratio in the water varied significantly during the growth periods. The results indicated that C. roscoffensis had flexible physiological strategies in utilizing varied phosphorus resources, and high cell density maintenance of C. roscoffensis may play roles in nutrient conditions in the water. This study may help to extend the understanding of nutrient utilization strategy in microalgae and to apply reference in the application of Chrysotila species in the removal of nutrient pollution.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121860
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1861: Analytical Solutions of Steady a Seepage Field
           for Deep-Buried Tunnel with Grouting Ring Considering Anisotropic Flow

    • Authors: Qizhi Chen, Luju Liang, Baoping Zou, Changjie Xu, Bowen Kong, Jingyuan Ma
      First page: 1861
      Abstract: Difficulties related to seepage are frequently encountered in tunnel design and construction, especially in deep-buried tunnels. Nowadays, analytical solutions of steady seepage fields for deep-buried tunnel usually assume that the surrounding rock mass is homogeneous. In this study, analytical solutions of a steady seepage field for a deep-buried tunnel with grouting ring considering anisotropic flow are proposed. The proposed analytical solutions are verified by numerical simulations and parameter analysis are carried out. Results show that the seepage field of surrounding rocks around the deep buried circular tunnel is no longer uniformly distributed and presents elliptical distribution. The change of permeability coefficient of the lining structure has a great influence on the hydraulic head when the difference between permeability coefficient of lining structure and surrounding rock is not very large. The results show that the size of the grouting ring has more significant influence on the grouting effect.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121861
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1862: Benthic Microbial Communities and Environmental
           Parameters of Estuary and Hypoxic Zone in the Bohai Sea, China

    • Authors: Fan Gao, Huade Zhao, Pengfei Zhao, Cuiya Zhang, Guangjing Xu, Guize Liu, Xianyong Guo
      First page: 1862
      Abstract: The sediment microbial community plays a key role in the cycling of organic matter in marine ecosystems. The characteristics of the sediment microbial community are significantly related to changes in the environment. In this study, we analyzed the diversity and distribution of microbial communities in sediments from different geographical regions (the Liao River estuary, Yellow River estuary, hypoxic zone, and offshore zone) of the Bohai Sea using high-throughput sequencing. The results showed that the community richness and diversity (especially the unique diversity) of the Liao River estuary were larger than those of the Yellow River estuary, hypoxic zone, and offshore zone. The phylum Proteobacteria dominated in the Liao River estuary (46.26%), hypoxic zone (76.19%), and offshore zone (69.79%), while the dominant phylum in the Yellow River estuary was the Bacteroidetes phylum. The genus Gillisia was the dominant genus in both the Liao River estuary and Yellow River estuary. The offshore zone and hypoxic zone shared the same dominant Photobacterium genus. The results of Pearson correlation and redundancy analysis showed that environmental parameters such as nitrite, silicate, nitrate, phosphate, ammonia, dissolved oxygen, pH, and salinity interfered significantly with the structure and diversity of the microbial community. The results of this study will provide support for future research on the interaction mechanism of pollutants and microorganisms in the estuaries and a typical hypoxic zone of the Bohai Sea.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121862
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1863: Predicting the Effect of Hull Roughness on Ship
           Resistance Using a Fully Turbulent Flow Channel

    • Authors: Roberto Ravenna, Ryan Ingham, Soonseok Song, Clifton Johnston, Tahsin Tezdogan, Mehmet Atlar, Yigit Kemal Demirel
      First page: 1863
      Abstract: The consequences of poor hull surface conditions on fuel consumption and emissions are well-known. However, their rationales are yet to be thoroughly understood. The present study investigates the hydrodynamics of fouling control coatings and mimicked biofouling. Novel experimental roughness function data were developed from the “young” fully turbulent flow channel facility of the University of Strathclyde. Different surfaces, including a novel hard foul-release coating, were tested. Finally, the performance of a benchmark full-scale containership was predicted using Granville’s similarity law scaling calculations. Interestingly, the numerical predictions showed that the novel hard foul-release coating tested had better hydrodynamic performance than the smooth case. A maximum 3.79% decrease in the effective power requirements was observed. Eventually, the results confirmed the practicality of flow channel experiments in combination with numerical-based methods to investigate hull roughness effects on ship resistance and powering. The present study can also serve as a valuable guide for future experimental campaigns using the fully turbulent flow channel facility of the University of Strathclyde.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121863
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1864: A BEM-Based Model of a Horizontal Axis Tidal
           Turbine in the 3D Shallow Water Code SHYFEM

    • Authors: Micol Pucci, Chiara Di Garbo, Debora Bellafiore, Stefania Zanforlin, Georg Umgiesser
      First page: 1864
      Abstract: We present a novel 3D implementation of a horizontal axis tidal turbine (HATT) in the shallow water hydrostatic code SHYFEM. The uniqueness of this work involves the blade element momentum (BEM) approach: the turbine is parameterized by applying momentum sink terms in the x and y momentum equations. In this way, the turbine performance is the result of both the flow conditions and the turbine’s geometric characteristics. For these reasons, the model is suitable for farm-layout studies, since it is able to predict the realistic behavior of every turbine in a farm, considering the surrounding flow field. Moreover, the use of a shallow water code, able to reproduce coastal morphology, bathymetry wind, and tide effects, allows for studying turbine farms in realistic environments.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121864
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1865: CFD Simulations of the Effect of Equalizing
           Duct Configurations on Cavitating Flow around a Propeller

    • Authors: Joseph Mwangi Ng’aru, Sunho Park
      First page: 1865
      Abstract: This study presented the results of a computational study of cavitating flows of a marine propeller with energy saving equalizing ducts. The main purpose of the study was to estimate the cavitating flows around a propeller with a duct, and to investigate the interaction between a duct and a propeller in cavitating flows. The INSEAN E779A propeller was used as a baseline model. Validation studies were conducted for non-cavitating and cavitating flows around a hydrofoil and a propeller. A comparison with the experimental data showed good agreement in terms of sheet cavity patterns and propulsion performances of the propeller. Various duct configurations have been presented, and it was found that a duct in front of the propeller had effects on the propeller’s cavitation and propulsion performance. Higher angles of attack of the duct showed a significant effect on the propeller’s cavitation behavior, especially with a small duct. The small duct lowered the cavitation inception radius with increase in angle of attack of the duct, while the large duct had more effect on the tip cavitation. The propeller with large duct gave higher thrust, however, the higher torque loading affected the propeller efficiency. Overall, it was found that the propeller with small duct provided a higher propeller efficiency
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121865
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1866: Influence of Stern Rudder Type on Flow Noise of
           Underwater Vehicles

    • Authors: Chunxu Wang, Lei Huang, Yue Zhao, Jinchi Dai, Yichen Jiang
      First page: 1866
      Abstract: The stern rudder of an underwater vehicle has a significant impact on the wake field and the flow noise. Hence, it is important to optimize the design of the stern rudder for reducing the radiated noise. In this work, a numerical model is set up to predict the flow noise of the underwater vehicle, based on the LES turbulence model and FW-H acoustic analogy method. After the verification study, the numerical prediction of the flow noise is compared with the experimental measurements to verify the accuracy of the numerical model. Then, the influence of sails on the flow noise is explored. It is observed that the existence of the sail significantly increases the noise at the low frequency. Furthermore, to examine the influence of the stern rudder type, the sound pressure levels of underwater vehicles with three full appendages having cross-type rudders, X-type rudders, and T-type rudders, are compared. The strong interaction between the sail’s wake and the stern rudder is evident. The underwater vehicle with T-type rudders exhibits the lowest sound pressure. In addition, the influence of the stern rudder type on the directivity of sound pressure levels is also presented.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121866
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1867: APSO-MPC and NTSMC Cascade Control of
           Fully-Actuated Autonomous Underwater Vehicle Trajectory Tracking Based on
           RBF-NN Compensator

    • Authors: Han Bao, Haitao Zhu, Xinfei Li, Jing Liu
      First page: 1867
      Abstract: In this paper, a model predictive control (MPC) method optimized by an adaptive particle swarm optimization (APSO) algorithm is proposed. Combined with non-singular terminal sliding mode control (NTSMC), the inner and outer double-closed-loop control system is constructed to solve the fully actuated autonomous underwater vehicle (AUV) dynamic trajectory tracking control problem. First, the outer loop controller generates the expected optimal velocity commands and passes them to the inner loop velocity controller, which generates the available control inputs to ensure the entire closed-loop trajectory tracking. In the controller design stage, system input and state constraints are effectively considered. After that, a compensator based on an adaptive radial basis function (RBF) neural network (NN) is designed to compensate for the model error and external sea state disturbances and to improve the control accuracy of the system. Then, the stability of the proposed controller is proved based on Lyapunov analysis. Finally, the dynamic trajectory tracking performance of an AUV with different sea state disturbances is verified by simulation, and the simulation results are compared with double-closed-loop PD control and cascade control of standard MPC based on PSO and SMC. The results show that the designed controller is effective and robust.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121867
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1868: Spatial Temporal Expansion of Harmful Algal
           Blooms in Chile: A Review of 65 Years Records

    • Authors: Camila Barría, Piera Vásquez-Calderón, Catalina Lizama, Pablo Herrera, Anahi Canto, Pablo Conejeros, Orietta Beltrami, Benjamín A. Suárez-Isla, Daniel Carrasco, Ignacio Rubilar, Leonardo Guzmán, L. René Durán, Doris Oliva
      First page: 1868
      Abstract: Harmful Algal Blooms (HABs) have been classified depending on the causative organism and its impacts: non-toxic HAB (microalgae capable of affecting tourism and causing oxygen deficiency, which generates mortality of marine organisms), toxic HAB (microalgae capable of transferring toxins to the food chain), and ichthyotoxic HAB (microalgae capable of generating mechanical damage in fish). HABs represent a worldwide problem and have apparently increased in frequency, intensity, and geographic distribution at different latitudes. This review details the occurrence of HAB events in the Southeast Pacific, Chile, over a 65-year period, analysing two of the three types of HAB described: toxic and ichthyotoxic HABs. For this, we conducted a review from many different scientific sources and from the written press and social media, that have mentioned HAB events in the country. In Chile, the microalgae involved in HAB events are dinoflagellate (52%), diatoms (33%) and silicoflagellate (10%), with a total of 41 species and/or genera described in the literature. A total of 501 HAB events were recorded in Chile between 1956 and 2021, where 240 (47.9%), 238 (47.5%), 14 (2.7%), 8 (1.5%) and 1 (0.2%) event were caused by diatoms, dinoflagellate, silicoflagellate, raphidophycean and haptophyte, respectively. An apparent increase in the frequency of HAB events is observed since the first record in 1956, with a maximum of 46 events during the years 2017 and 2019. The highest incidence in fish is caused by the group of silicoflagellate, raphidophycean and haptophyte (23 events), where 10 events caused mortalities in salmon with an incidence rate of 43.4%. Unlike what is observed with diatoms and dinoflagellate, the events associated with these groups are less frequent, but hold a much higher salmon mortality rate. During the last 65 years, HAB’s geographic extent shows an apparent trend to increase south-to-north. However, the identification of events is closely linked to the areas where much of the country’s aquaculture is located and, therefore, it could be biased. In turn, it is observed that the apparent increase in HAB events could be associated with a greater monitoring effort after major events (e.g., after the 2016 HAB event). On the other hand, it is also recognized a lack of knowledge about harmful algae throughout the Chilean Humboldt Current system, particularly in the northern regions, such as Atacama and Coquimbo. Therefore, the total number of blooms that have occurred in fjords and channels, particularly those that have caused minor economic impacts for artisanal fishermen and the salmon and mussel farming sector, might be underestimated.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121868
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1869: Numerical Study on the Interaction between
           Ocean Current Power Generator and Unmanned Underwater Vehicle

    • Authors: Shenggui Wang, Jiyuan Sun, Bowen Zhao, Yingying Yun, Bin Huang
      First page: 1869
      Abstract: The unmanned underwater vehicle (UUV) can effectively utilize marine renewable energy after equipping the UUV with an accompanying power generator that improve its long-range endurance. In order to study the interaction between the UUV and the ocean current power generator, a coupled hydrodynamic model of the counter-rotating type turbine and the UUV hull was established. Based on the RANS model and the sliding grid method, this paper analyzed the influence of the ocean current power generator on the straight-ahead resistance and hydrodynamic coefficient of the UUV in the non-working state, and calculated the UUV yaw moment and its surrounding flow field characteristics with the power generator in the working state. Then, the effect of the drift angle on the performance of the counter-rotating type turbine was explored. The results show that the straight-ahead resistance of the UUV increased slightly after equipping the power generator, but the increase was within 14%, and the characteristics of the surrounding flow field of the UUV did not changed greatly. The difference in the linear hydrodynamic coefficients before and after equipping the UUV with the power generator was within 7%. At most drift angles, when the generator was in the working state, the yaw moment of the hull was greater than the condition when the generator was not equipped. Nevertheless, the overall trend of the two sides was similar, so the rotation of the counter-rotating type turbine did not reduce the stability of the hull in the moored state. In addition, when the drift angle was greater than 50°, the UUV hull had a great impact on the performance of the counter-rotating type turbine; the power coefficient and thrust coefficient increased by about 35.7% and 17.8%, respectively. This paper provides a good reference value for the design of the power generation mode of the UUV equipped with a counter-rotating type turbine.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121869
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1870: How do Gene Expression Patterns Change in
           Response to Osmotic Stresses in Kuruma Shrimp (Marsupenaeus
           japonicus)'

    • Authors: Yuquan Li, Zhihao Zhang, Zhongkai Wang, Zhitong Deng, Ruiyang Zhao, Jinfeng Sun, Pengyuan Hao, Long Zhang, Xiaofan Wang, Fei Liu, Renjie Wang, Yanting Cui
      First page: 1870
      Abstract: Euryhaline crustaceans cope with external salinity changes by mechanisms of osmoregulation. In the current study, we first cloned and confirmed the ORF sequences of the ion-transportation-related genes Na+/K+-ATPase α subunit (NKAα), cytoplasmic carbonic anhydrase (CAc), and V-type H+-ATPase G subunit (VHA-G), and water channels of aquaporins (AQP3, AQP4, and AQP11) from kuruma shrimp (Marsupenaeus japonicus). Further tissue expression patterns showed a higher expression of MjAQP4, MjCAc, MjNKAα, and MjVHA-G in the gills, as well as a higher expression of MjAQP3 and MjAQP11 in the intestine and muscle, respectively. Then, qPCR analysis was used to assess the mRNA expression levels of those osmoregulatory genes in both post-larvae and adult shrimp when they were exposed to acute salinity stress or salinity acclimation. The results revealed significantly decreased expression levels of MjAQP3, MjAQP11, MjNKAα, and MjCAc, and higher expression levels of MjAQP4 and MjVHA-G when the post-larvae shrimp were directly subjected to 10‰ or 50‰ salinity. Moreover, similar expression patterns were also observed in the post-larvae shrimp during the accommodation to 10‰ or 50‰ salinity. As to the adult shrimp, significantly higher expression levels of those genes were observed in the gills after exposure to 10‰ salinity, whereas only the expression levels of MjAQP3, MjAQP11, and MjNKAα were up-regulated in the gills at 40‰ salinity. In contrast, the expression of MjVHA-G was significantly decreased at 40‰ salinity. Finally, during the acclimation to 10‰ salinity, the expression levels of MjAQP3, MjAQP11, and MjNKAα were also significantly elevated, while the expression of MjCAc was significantly decreased in the gills. In addition, the expression levels of MjAQP3, MjAQP4, MjCAc, and MjVHA-G were significantly decreased in the gills during the acclimation to 55‰ salinity. The findings of the study suggest that the examined genes are critical for the adaptation of aquatic crustaceans to changing environmental salinity. Our study lays as the foundation for further research on osmoregulation mechanisms in M. japonicus.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121870
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1871: On Sea-Level Change in Coastal Areas

    • Authors: Vincent Courtillot, Jean-Louis Le Le Mouël, Fernando Lopes, Dominique Gibert
      First page: 1871
      Abstract: Variations in sea-level, based on tide gauge data (GSLTG ) and on combining tide gauges and satellite data (GSLl), are subjected to singular spectrum analysis (SSA) to determine their trends and periodic or quasi-periodic components. GLSTG increases by 90 mm from 1860 to 2020, a contribution of 0.56 mm/yr to the mean rise rate. Annual to multi-decadal periods of ∼90/80, 60, 30, 20, 10/11, and 4/5 years are found in both GSLTG and GSLl. These periods are commensurable periods of the Jovian planets, combinations of the periods of Neptune (165 yr), Uranus (84 yr), Saturn (29 yr) and Jupiter (12 yr). These same periods are encountered in sea-level changes, the motion of the rotation pole RP and evolution of global pressure GP, suggesting physical links. The first SSA components comprise most of the signal variance: 95% for GSLTG, 89% for GSLl, 98% for GP and 75% for RP. Laplace derived the Liouville–Euler equations that govern the rotation and translation of the rotation axis of any celestial body. He emphasized that one must consider the orbital kinetic moments of all planets in addition to gravitational attractions and concluded that the Earth’s rotation axis should undergo motions that carry the combinations of periods of the Sun, Moon and planets. Almost all the periods found in the SSA components of sea-level (GSLl and GSLTG), global pressure (GP) and polar motion (RP), of their modulations and their derivatives can be associated with the Jovian planets. The trends themselves could be segments of components with still longer periodicities (e.g., 175 yr Jose cycle).
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-02
      DOI: 10.3390/jmse10121871
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1872: Potential Influence of Offshore Wind Farms on
           the Marine Stratification in the Waters Adjacent to China

    • Authors: Zhan Lian, Kun Liu, Tong Yang
      First page: 1872
      Abstract: Offshore wind farms (OWFs) can influence marine stratifications, leading to fuel nutrition in the upper ocean and regulating ocean carbon fluxes. Evaluating this dynamic effect facilitates the planning of OWFs deployment for enlarging marine carbon sequestration, which is urgent in the pursuit of China’s carbon neutrality targets. However, it is impossible to observe the target influence in the planning stage of deployments, and it is impractical to build a high-resolution (100~101 m) model to cover the entire waters adjacent to China. The theoretical calculations, therefore, are the first step and top priority. The simplified theory presents two suggestions in the design of future OWF deployments in the study area. The first suggestion is made from the perspective of OWF positioning. To the east of the cities of Zhoushan, Putian, and Shantou, the oceans are dynamically sensitive to OWF deployments. The second suggestion is made from the perspective of the length scale of OWFs. A broader OWF results in a smaller vertical disturbance in the coastal waters, but the situation is opposite in the open seas. The OWF deployment strategy, proposed in the aim of ensuring idealized marine stratification responses, thus varies geographically. This study provides a panoramic view of the sensitivity of marine stratification to OWFs in the study regions. It can be seen as a steppingstone in detailed research of the target phenomenon.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121872
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1873: The Morphology, Genetic Diversity, and
           

    • Authors: Meijuan Hu, Shuang Zhao, Jinlin Liu, Yichao Tong, Zhangyi Xia, Jing Xia, Shuang Li, Yuqing Sun, Jiaxing Cao, Jianheng Zhang
      First page: 1873
      Abstract: Green tides originate from the rapid growth of green macroalgae and their large accumulation. In the past few decades, the severity and frequency of green tides have increased and the range of their geographical distribution has widened. In recent years, Ulva meridionalis Horimoto et Shimada has been reported in many countries. This species has stable morphological characteristics, and its length can reach 3 m in indoor cultures. Its cells contain pyrenoids, and the sporangium and gametangium of each cell contain 8 spores and 16 gametes, respectively, which confer a high proliferation potential. The phylogenetic tree constructed in this study showed that the Internal Transcribed Spacer sequence identified U. meridionalis with a high identification reliability, and the genetic relationship between U. meridionalis and Ulva pertusa in the ITS sequence was close. The haplotype network analysis clarified the relationship of the U. meridionalis samples collected from four different sea areas in China and indicated that they were closely related. Five haplotypes were identified: Hap_2 and Hap_1 were the most frequent, and they were also the haplotypes shared among the three groups. The degree of subspecies formation was not reached among these U. meridionalis samples collected from the Chinese seas. Up to 20 years ago, U. meridionalis had only been recorded in Japan. After 2011, it has been found to be widely distributed in the United States, China, French New Caledonia, French Polynesia, and Australia, where it proliferates. It has spread as a new kind of green tide-forming macroalga. The present study found that U. meridionalis is widely distributed in the Chinese seas; specifically, there have been small-scale blooms in the Bohai Sea, the Yellow Sea, and the South China Sea. Further investigations should focus on establishing whether U. meridionalis will cause large-scale green tide events in the future.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121873
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1874: Dumbbell-Shaped Damage Effect of Closed
           Cylindrical Shell Subjected to Far-Field Side-On Underwater Explosion
           Shock Wave

    • Authors: Yuhao Wang, Hongxiao Dong, Tong Dong, Xiangyun Xu
      First page: 1874
      Abstract: In naval warfare, underwater explosion (UNDEX) shock waves significantly influence the stability and safety of the pressure hull structure of the equipment. This study investigated the unique dynamic buckling of a closed cylindrical shell subjected to a far-field side-on UNDEX shock wave using a three-dimensional numerical simulation based on acoustic–structural arithmetic. In particular, the flow-field response characteristics, plastic deformation, and yield characteristics of the cylindrical shell were determined under the influence of the UNDEX shock wave. Subsequently, the failure mode of the cylindrical shell was analyzed to propose the dumbbell-shaped damage effect. The results revealed that when the UNDEX shock wave encounters a finite cylindrical shell, the fluid exhibits a perturbation such as pressure division, stress wave deflection, and flow in the surroundings of the circular cylinder. However, the fluid cannot produce a sizeable instantaneous displacement that yields certain strong constraints at both ends of the cylindrical shell. These constraints generate an irregular distribution of the flow field pressure, and the cylindrical shell tends to exhibit an “arch” deformation along the direction of shock wave propagation. Owing to the flow surrounding the circular cylinder, a negative pressure zone is generated in the flow field at both ends of the cylindrical shell, which induces a “sucking disc” shape at both ends of the cylindrical shell and ultimately produces a dumbbell-shaped damage effect. The present findings will aid in the structural design and impact resistance of submarines, unmanned undersea vehicles, and additional equipment under the impact load of the UNDEX.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121874
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1875: A New Approach to Integrated Multi-Trophic
           Aquaculture System of the Sea Cucumber Apostichopus japonicus and the Sea
           Urchin Strongylocentrotus intermedius

    • Authors: Fangyuan Hu, Huiyan Wang, Ruihuan Tian, Jujie Gao, Guo Wu, Donghong Yin, Chong Zhao
      First page: 1875
      Abstract: The sea cucumber Apostichopus japonicus and the sea urchin Strongylocentrotus intermedius are two commercially important species and are widely cultured in China. Here, a laboratory experiment was conducted for 34 days to assess whether the survival, growth and behavior performances are better in the new commercially valuable integrated multi-trophic aquaculture (IMTA) system (group M, 90 S. intermedius and 37 A. japonicus/10,638 cm3 of stocking density) than those in the control group for sea urchins (group U, 90 S. intermedius/10,638 cm3 of stocking density) and the control group for sea cucumbers (group C, 37 A. japonicus/10,638 cm3 of stocking density). We found that feeding behavior, crawling behavior, body length and body weight of sea cucumbers were significantly greater in group M than those in group C. These results suggest that the new IMTA system improves fitness-related behaviors and consequently leads to a better growth in A. japonicus while maintaining a high biomass. We further found that group M showed significantly larger body size and Aristotle’s lantern reflex as well as significantly lower mortality and morbidity in sea urchins, compared to those in group U. This suggests that the new IMTA system greatly improves feeding behavior and body growth, and survival of cultured S. intermedius. This IMTA system is a promising candidate to promote the production efficiency of juvenile A. japonicus (as primary species) and S. intermedius (as subsidiary species) in China.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121875
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1876: Ecomorphological Differentiation of Feeding
           Structures within the Antarctic Fish Species Flock Trematominae
           (Notothenioidei) from Terra Nova Bay (Ross Sea)

    • Authors: Erica Carlig, Davide Di Di Blasi, Eva Pisano, Marino Vacchi, Gianfranco Santovito, Laura Ghigliotti
      First page: 1876
      Abstract: The Antarctic endemic fish genus Trematomus (Trematominae, Notothenioidei) includes 15 species very diverse in morphology, lifestyle and feeding ecology. Co-occurring on the continental shelf, they occupy different habitats and a wide range of ecological niches as the result of adaptive radiation during their evolutionary history. Ecomorphological differentiation is a key feature of adaptive radiations, with a general trend for specialization following divergence. Here, we investigated the trophic adaptive morphology and ecology of six Trematomus species from Terra Nova Bay (Ross Sea) through feeding apparatus metrics and geometric morphometrics. The suction index (SI), the mechanical advantage in jaw closing (MA), the relative surface of the adductor mandibulae muscle and nine morphological traits related to feeding structures were analysed. Head shape clearly differentiates the benthic (T. bernacchii, T. hansoni and T. pennellii) from the pelagic (T. eulepidotus and T. borchgrevinki) species. The position of the eyes and the orientation of the mouth also contribute to specific morphological differences and specialization. Interestingly, T. newnesi stands at an intermediate position and the mouth is clearly oriented upwards compared to the other congeneric species.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121876
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1877: Forensic Analysis of Residual Oil along Abu Ali
           Island, Saudi Arabia

    • Authors: Jacqueline Michel, Zachary Nixon, Linos Cotsapas, Scott Zengel, Jennifer Weaver, Harold Fravel, Philip Bambach
      First page: 1877
      Abstract: Extensive asphalt pavements have persisted along >25 km (km) of shoreline on Abu Ali Island, on the Arabian (Persian) Gulf coast of Saudi Arabia, reportedly stranding as a result of the 1983–1985 Nowruz oil spills. A study was conducted in October 2020 to support development of a remediation plan. Cross-shore transects were surveyed at 100 m intervals and 1434 shovel test pits were dug to determine oil type, thickness, and depth of burial. Oiling of any description was observed at 76% of the pits. Using 15 diagnostic biomarker ratios, only 5 of the 94 oiled samples from Abu Ali Island in 2020 likely contain other oils. Data on historical spills were identified from the literature. Based on chemical biomarker data for potential source oils in the northern Arabian (Persian) Gulf, the diagnostic ratio for the biomarkers 18a-22,29,30-Trisnorneohopane (Ts) and 17a(H)-22,29,30-Trisnorhopane (Tm) for the 94 samples only matched one Iraq crude oil. No large individual spills of Iraq crude oil were identified in the literature or spill databases, although releases of both Kuwait and Iraq crudes were reported for the 1991 Gulf War oil spills. However, oil residues from Abu Ali did not match most prior samples of Saudi shoreline oiling from the Gulf War oil spills, which largely consisted of spilled Kuwait crude. Though we cannot definitely conclude that the majority of the residual oil on Abu Ali Island delineated during the 2020 survey is oil from the Nowruz oil spills, because there is no source oil from these spills, we use a weight of evidence approach to say that it is highly likely that the majority of the residual oiling is from the Nowruz spills.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121877
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1878: High Throughput Sequencing Reveals Distinct
           Bacterial Communities and Functional Diversity in Two Typical Coastal Bays
           

    • Authors: Liao Ouyang, Xianglan Chen, Wenxuan Zhang, Shuangfei Li, Qiang Huang, Yi Zhang, Chengwei Yan, Shaofeng Li
      First page: 1878
      Abstract: The marine waters in semi-enclosed bays are highly dynamic and strongly influenced by different levels of anthropogenic activity. This study explored the bacterial community composition and diversity in two typical urbanized coastal bay areas (Shenzhen Bay (S) and Dapeng Bay (D)) in Shenzhen, China, based on Illumina NovaSeq sequencing. Seawater analysis showed that coastal area S experienced a higher level of pollution, with higher nutrient concentrations observed. Alpha diversity analysis showed a higher bacterial diversity and richness in coastal area S than D. Taxonomic analysis revealed that the phylum Proteobacteria showed the highest abundance in all samples. Other dominant phyla were Firmicutes, Cyanobacteria, Tenericutes, and Actinobacteria. The bacterial community compositions were significantly different between the two coastal areas. A significant community difference was also found between the sampling sites of coastal area S. However, the difference between sampling sites in coastal area D was not significant. Physicochemical factors showed a more significant effect on bacterial community composition than nutrients. Pearson correlation tests and Network analysis further confirmed that salinity/conductivity, pH, and nitrate were the key factors driving the community difference. PICRUSt analysis revealed a higher degree of functional pathways in coastal area S relating to carbohydrate metabolism, membrane transport, and xenobiotics biodegradation. Our results provide in-depth insights into the bacterial community compositions in typical polluted coastal bays. They may provide information on underlying factors of the assembly process in microbial communities in the coastal zone.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121878
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1879: Fatigue Strength Assessment of Single-Sided
           Girth Welds in Offshore Pipelines Subjected to Start-Up and Shut-Down
           Cycles

    • Authors: Yan Dong, Guanglei Ji, Lin Fang, Xin Liu
      First page: 1879
      Abstract: During the service life of offshore pipelines, many start-up and shut-down cycles take place, possibly leading to significant cyclic loads. Fatigue failure may occur, resulting in serious environmental pollution and loss of property. The study aims to assess the fatigue strength of single-sided girth welds in offshore pipelines under these specific fatigue loads. The longitudinal stress range caused by the variation of the pipeline’s internal pressure and temperature is calculated. The effective notch strain approach is used to assess the fatigue strength of welds. The plastic behaviour of the weld root is investigated for a study case to justify the use of low-cycle fatigue assessment approaches. The effect of weld root geometry on the notch stress factor is studied to identify the dominant geometrical parameters. The fatigue strength of the study case is assessed, and some limitations of the assessment are discussed. The results show that the plastic behaviour of the weld root is only significant for severe local stress concentrations, which is mainly governed by the axial misalignment, weld root angle and the weld root bead width. If the fatigue damage at failure is 0.1, a limited number of start-up and shut-down cycles are allowed during the service life of the pipeline for the study case, indicating the necessity of fatigue strength assessment.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121879
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1880: Study on Sound Velocity and Attenuation of
           Underwater Cobalt-Rich Crust Based on Biot and BISQ Theories

    • Authors: Gang Hu, Haiming Zhao, Zelin Li
      First page: 1880
      Abstract: A prediction model of the sound velocity and sound attenuation of underwater cobalt-rich crusts (CRCs) was established to solve the problem that it is difficult to predict the sound velocity in thickness measurements of cobalt-rich crusts. Based on Biot theory and BISQ theory, a simplified Biot and BISQ model was proposed for the prediction of the sound velocity and sound attenuation of CRCs by using the Kozeny–Carman (KC) equation. The models could calculate the sound velocity and attenuation by the porosity and detection frequency. Based on the physical and mechanical properties of CRCs, a similarity model of the sound velocity and sound attenuation of CRCs was made by using the similarity theory to solve the problem that it is difficult to measure the acoustic propagation characteristics of CRCs. The sound velocity and sound attenuation of CRC similarity models with different porosities were measured by an underwater transmission experiment and the results of the simplified model calculation and experimental measurements were compared. The results showed that the simplified Biot model was suitable for the CRC sound velocity prediction and the simplified BISQ model was suitable for the CRC sound attenuation prediction, which had a high prediction accuracy.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121880
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1881: Application of SWASH to Compute Wave
           Overtopping in Ericeira Harbour for Operational Purposes

    • Authors: Anika Manz, Ana Catarina Zózimo, Juan L. Garzon
      First page: 1881
      Abstract: This work aimed at testing the capability of the numerical model SWASH to be implemented in the prototype of the overtopping and flooding forecast system HIDRALERTA for Ericeira harbour. In contrast to the neural network NN_OVERTOPPING2, which is currently implemented in HIDRALERTA, SWASH is able to estimate the flood extension and wave propagation along the domain, which makes it a possible improvement to NN_OVERTOPPING2. The one-dimensional version of the SWASH model was implemented to simulate overtopping at two different profiles (antifer and tetrapods) and calibrated for three storms in 2019 by comparing the simulated overtopping discharge to NN_OVERTOPPING2 results. For the calibration, the Manning coefficient was used to represent the friction of the armour layer. Then, for operational purposes, four expressions to calculate the Manning coefficient were developed based on: the relative crest freeboard, the wave steepness, the incident wave angle and the type of armour layer. The expressions showed small errors between the calculated and calibrated Manning coefficients and highlighted the importance of the incident wave angle to obtain an accurate calibration. Despite an underestimation of the overtopping discharge in some cases, the SWASH model was found to provide overall good results when applied with calculated Manning coefficients and suitable to be implemented in HIDRALERTA.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121881
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1882: Alternative Power Options for Improvement of
           the Environmental Friendliness of Fishing Trawlers

    • Authors: Marija Koričan, Maja Perčić, Nikola Vladimir, Neven Alujević, Ailong Fan
      First page: 1882
      Abstract: The fishing sector is faced with emission problems arising from the extensive use of diesel engines as prime movers. Energy efficiency, environmental performance, and minimization of operative costs through the reduction of fuel consumption are key research topics across the whole maritime sector. Ship emissions can be determined at different levels of complexity and accuracy, i.e., by analyzing ship technical data and assuming its operative profile, or by direct measurements of key parameters. This paper deals with the analysis of the environmental footprint of a fishing trawler operating in the Adriatic Sea, including three phases of the Life-Cycle Assessment (manufacturing, Well-to-Pump (WTP), and Pump-to-Wake (PTW)). Based on the data on fuel consumption, the viability of replacing the conventional diesel-powered system with alternative options is analyzed. The results showed that fuels such as LNG and B20 represent the easiest solution that would result in a reduction of harmful gases and have a positive impact on overall costs. Although electrification and hydrogen represent one of the cleanest forms of energy, due to their high price and complex application in an obsolete fleet, they do not present an optimal solution for the time being. The paper showed that the use of alternative fuels would have a positive effect on the reduction of harmful emissions, but further work is needed to find an environmentally acceptable and economically profitable pathway for redesigning the ship power system of fishing trawlers.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121882
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1883: Magnetic Plug Sensor with Bridge Nonlinear
           Correction Circuit for Oil Condition Monitoring of Marine Machinery

    • Authors: Yuwei Zhang, Jiaju Hong, Haotian Shi, Yucai Xie, Hongpeng Zhang, Shuyao Zhang, Wei Li, Haiquan Chen
      First page: 1883
      Abstract: Diesel engines in marine power systems often work in extreme environments. Oil monitoring technology can guarantee the operational safety of diesel engines. In this paper, a magnetic plug sensor for oil debris monitoring is proposed to improve sensitivity and accuracy. Through finite element analysis, absolute deviation is reduced by optimizing the sensor structure. A bridge nonlinear correction circuit is designed to make sensitivity consistent over the entire scale range, which can facilitate calibration and data processing. In order to reduce noise and amplify the signal effectively, a signal post-processing circuit is adopted as well, which consists of a first stage filter circuit, a second stage filter, an active filter module, and an instrumentation amplifier. Therefore, this magnetic plug sensor exhibits better sensitivity and accuracy. Furthermore, a void test and a dynamic test are carried out to investigate its performance. There is a linear relationship between the voltage and the particle mass for the sensor with a bridge nonlinear correction circuit. The results illustrate a minimum of 0.033 mg iron debris with a 1.647 signal-to-noise ratio. Additionally, it can capture and detect 47 μm particles with a debris capture rate of over 90%, which allows it to excel in early fault diagnosis as well.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-03
      DOI: 10.3390/jmse10121883
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1884: Numerical Simulation of Wave–Current
           Force Characteristics of Horizontal Floating Cylinder in Heave Motion

    • Authors: Xiaoguo Zhou, Qingdian Jiang, Yan Wang, Linfeng Chen, Shuqi Wang, Kunpeng Wang
      First page: 1884
      Abstract: This paper presents the characteristics of the heave motion responses and hydrodynamic forces of a horizontal floating circular cylinder during a wave–current interaction. A two-dimensional numerical model based on the CFD (Computational Fluid Dynamics) method for modeling wave flow is validated and verified. The hydrodynamic characteristics of the horizontal floating cylinder during heave motion were calculated and analyzed under the conditions of different k values (stiffness of spring), wave amplitudes, submerged depths, and flow rates. The results show that, with the increase in the k value, the vibration amplitude of the cylinder first increases and then decreases. The vibration amplitude peak is achieved, the vibration frequency is consistent with the wave frequency, and a resonant motion takes place. When the wave amplitude and flow rate are fixed, the maximum vibration amplitude decreases as the wave period increases. When the cylinder is half-submerged, the effect of the current on motion is significant; the vibration amplitude is less than the wave amplitude. When a quarter is submerged, the vibration amplitude is larger than that of the half-submerged cylinder at each k. The maximum amplitude is greater than the wave amplitude, and the vibration amplitude reaches the minimum at the moderate flow rate for each k.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121884
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1885: Integrating Shipping Domain Knowledge into
           Computer Vision Models for Maritime Transportation

    • Authors: Ying Yang, Ran Yan, Shuaian Wang
      First page: 1885
      Abstract: Maritime transportation plays a significant role in international trade and the global supply chain. To enhance maritime safety and reduce pollution to the marine environment, various regulations and conventions are proposed by international organizations. To ensure that shipping activities comply with the relevant regulations, more and more attention has been paid to maritime surveillance. Specifically, cameras have been widely equipped on the shore and drones to capture the videos of vessels. Then, computer vision (CV) methods are adopted to recognize the specific type of ships in the videos so as to identify illegal shipping activities. However, the complex marine environments may hinder the CV models from making accurate ship recognition. Therefore, this study proposes a novel approach of integrating the domain knowledge, such as the ship features and sailing speed, in CV for ship recognition of maritime transportation, which can better support maritime surveillance. We also give two specific examples to demonstrate the great potential of this method in future research on ship recognition.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121885
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1886: Mathematical Model of an Offshore Friction Pile
           in Multilayered Saturated Soils

    • Authors: Deyong Guan, Kun Meng
      First page: 1886
      Abstract: In this paper, an analytical methodology is proposed to study the vibration of an offshore friction pile embedded in multilayered saturated viscoelastic soils by combining Biot’s saturated wave propagation theory, Novak’s plane-strain model, and the fictitious saturated soil pile model. The corresponding semi-analytical solution for the dynamic response of the pile is developed considering the heterogeneity, porosity, and limited thickness of the soils. The approach and relevant solution presented are validated by comparisons with existing solutions. Furthermore, numerical instances are used to investigate the influences of the porosity and heterogeneity of the saturated soils around and beneath the pile on the vibration of the pile. The findings from this paper provide a theoretical reference for a comprehensive understanding of the wave propagation characteristics of a friction pile embedded in heterogeneous saturated soil with limited thickness.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121886
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1887: Numerical Investigation on Aerodynamic
           Characteristics of Dual-Rotor Wind Turbines

    • Authors: Kai Wang, Tianhui Liu, Yuanchen Wan, Muk Chen Ong, Tiecheng Wu
      First page: 1887
      Abstract: Improving power output and reducing costs are crucial to the sustainable development of offshore wind power. In the present study, a dual-rotor wind turbine (DRWT) is proposed to improve wind energy capture efficiency by adding an auxiliary rotor behind the main rotor. The two rotors can be the same size or different sizes. This will result in different aerodynamic characteristics for DRWTs. In this paper, the NREL Offshore Baseline-5 MW and the NREL 750 kW single-rotor wind turbines (SRWTs) are used to configure three different types of DRWTs. The power output and wake characteristics of three different DRWTs with co-rotating (CO-DRWT) and counter-rotating (CR-DRWT) configurations on an actual scale are compared. The Reynolds-averaged Navier–Stokes (RANS) model with k-ω SST (shear stress transport model) is used to simulate the unsteady flow generated by the DRWT’s rotation. The present numerical results show that the power coefficient of the 5 MW-5 MW CO-DRWT can reach 1.22 times that of the 5 MW SRWT. Moreover, a faster wake velocity deficit recovery is found in the 5 MW-5 MW DRWTs because the high-velocity flow caused by the merging and mixing of the trailing vortices of the 5 MW-5 MW DRWTs brings an energy supplement to the wake velocity deficit.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121887
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1888: Energy-Saving Depth Control of an Autonomous
           Underwater Vehicle Using an Event-Triggered Sliding Mode Controller

    • Authors: Yu Qi, Xinyu Wu, Guocheng Zhang, Yushan Sun
      First page: 1888
      Abstract: In order to improve the endurance of underwater vehicles and make it possible for the underwater vehicle to inspect long-distance water tunnels, a sliding mode control method based on event triggering is proposed for the depth control of underwater vehicles from the perspective of energy saving. Firstly, the kinematics and dynamics models of underwater vehicle dive surface are established. Secondly, an event-triggered sliding mode controller is designed. According to the Lyapunov function, the stability of the designed controller is proved by theoretical analysis, and Zeno phenomena will not appear in the closed-loop control system. Compared with other controllers, the simulation results show that this controller can effectively realize the depth control of AUV, has strong adaptability and robustness to unmodeled nonlinear dynamics and bounded disturbances, and has the effect of saving computing resources.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121888
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1889: Traffic Organization Service for Maritime
           Autonomous Surface Ships (MASS) with Different Degrees of Autonomy

    • Authors: Wenqiang Guo, Xinyu Zhang, Jingyun Wang, Hongxiang Feng, Nyamatari Anselem Tengecha
      First page: 1889
      Abstract: Maritime Autonomous Surface Ships (MASS) have been an important direction for the development of intelligent shipping. However, most current international research on MASS focuses on navigation assistance technologies such as perception and decision-making, ignoring MASS’s traffic organization and management. The traffic organization service (TOS) under the e-Navigation strategy also has not researched MASS. In this paper, we propose the notion of on-demand service to MASS with different degrees of autonomy (DoA) and develop a new maritime service (MS) applicable to the MASS with various (DoA) following the e-Navigation technical architecture. We first analyze MASS requirements with different degrees of autonomy in traffic organization to define the service information. Then, based on the traditional TOS, we developed the MASS traffic organization service (MTOS), consisting of an operational architecture, five subsystems, and four services. In particular, we proposed a phased service trigger mechanism to solve the problem of publishing untimely and redundant service information. Tianjin port and Huanghua port were selected as cases study for simulation experiments; the study finding revealed that MTOS could provide standardized, accurate, and efficient traffic organization service for MASS with different degrees of autonomy on demand. The contribution can be applied in the port operation to improve traffic safety.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121889
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1890: A Decision-Support Model for the Generation of
           Marine Green Tide Disaster Emergency Disposal Plans

    • Authors: Bo Ai, Dan Zhang, Maoxin Jia, Xiaoliang Wang, Jingxia Gao, Lei Wang, Benshuai Li, Hengshuai Shang
      First page: 1890
      Abstract: Green tide is a harmful marine ecological phenomenon caused by the explosive proliferation or high aggregation of some macroalgae, and can cause significant impacts on ecological environments and economies. An effective emergency disposal plan can significantly improve disposal capacity and reduce total costs. At present, the formulation of emergency disposal plans for green tide disasters usually depends on subjective experience. The primary purpose of this paper is to develop a decision-support model based on intelligent algorithms to optimize the type and number of resources when making emergency disposal plans so as to improve the reliability and efficiency of decision making. In order to simulate the decision-making environment more realistically, the drift motion of green tide is considered in this model. Two intelligent algorithms, the Genetic Algorithm (GA) and the improved Non-Dominated Sorting Genetic Algorithm-II (IMNSGA-II), are used to solve the model and find appropriate emergency disposal plans. Finally, a case study on the green tide disaster that occurred in Qingdao (Yellow Sea, China) is conducted to demonstrate the effectiveness and optimization of the proposed model. Through the model proposed in this paper, the overall response time and cost can be reduced in green tide disaster emergency operations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121890
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1891: Assessment of Ship Fuel Consumption for
           Different Hull Roughness in Realistic Weather Conditions

    • Authors: Mina Tadros, Roberto Vettor, Manuel Ventura, C. Guedes Soares
      First page: 1891
      Abstract: This paper presents the effect of hull roughness over 10 years of operation on ship performance. The numerical model is developed by coupling NavCad and Matlab to perform the computation and the data processing. On the basis of a given hull, an engine, and an optimized propeller, the performance of the ship is computed for eight cases of hull roughness according to the ITTC recommendations in both calm waters and different weather conditions along the ship route. The effect of both wind and waves is considered for computing the added ship resistance along the route, thus requiring more power than just only the added resistance in waves. This provides a more accurate estimation of the ship’s performance along the different sea states. Lastly, a weighted average of the main ship parameters is estimated to evaluate better the ship’s performance. According to this study, the fuel consumption in calm water can be increased by around 20% after 10 years of ship operation based on the level of hull roughness. However, in the same weather conditions along the ship route, the ship’s fuel consumption can be increased by 10% compared to the same trip with a clean hull.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121891
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1892: Selective NO2 Detection by Black Phosphorus Gas
           Sensor Prepared via Aqueous Route for Ship Pollutant Monitoring

    • Authors: Yang Wang, Yujia Wang, Yue Sun, Kuanguang Zhang, Chenyang Zhang, Jianqiao Liu, Ce Fu, Junsheng Wang
      First page: 1892
      Abstract: The emission of nitrogen dioxide (NO2) caused by marine transportation has attracted worldwide environmental concerns. Two-dimensional (2D) black phosphorus (BP) is an emerging semiconductive material with the advantages of high electron mobility, a layer-dependent direct band gap and a large specific surface area. These properties ensure excellent potential in gas-sensing applications. In this work, BP quantum dots (QDs) are synthesized from commercial red phosphorus (RP) fine powder via the aqueous route. The BP QDs show uniform size distribution with an average size of 2.2 nm. They are employed to fabricate thin film gas sensors by aerial-assisted chemical vapor deposition. The microstructure, morphology and chemical composition are determined by various characterizations. The sensor performances are evaluated with the optimized response set to 100 ppm NO2 of 10.19 and a sensitivity of 0.48 is obtained. The gas sensor also demonstrates excellent repeatability, selectivity and stability. The fabricated thin film gas sensor assembled by BP QDs exhibits prospective applications in selective NO2 detection for marine gaseous pollutant monitoring and control.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121892
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1893: Application of Flexible Structure in Marine
           Engineering

    • Authors: Sarat Chandra Mohapatra
      First page: 1893
      Abstract: The aim of the Special Issue (SI) was to publish original and high-quality research papers that deal with model developments based on the mathematical, numerical, and experimental models associated with flexible floating or submerged structure applications in the discipline of marine engineering. [...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-04
      DOI: 10.3390/jmse10121893
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1894: Evolutionary Trajectories of Coastal Sand
           Barriers along the West Portuguese Coast during the Holocene

    • Authors: Susana Costas
      First page: 1894
      Abstract: Coastal sand barriers are dynamic features with complex depositional sequences holding critical information regarding system response to disturbances at secular to millennial time scales. Here, the evolutionary trajectories of three barriers located along the Portuguese coast are reconstructed over the Middle to Late Holocene using geophysical subsurface images, modern morphology and dating of dune and beach deposits. The integration of new and available information from the documents of the selected site contrasts histories with modern barriers displaying ages ranging from hundreds to thousands of years and non-linear trajectories defined by shifts between morphological states. Younger barriers appear to represent the latest progradational state within a history of landward barrier migration, where progradational states alternated with transgressive states. Conversely, the oldest barrier shows a single phase of barrier growth, despite some minor hiatus in progradation. Barrier state shifts appear to have simultaneously occurred across systems, suggesting external drivers of regional scale linked to Holocene climate variability, namely, periods of storminess activity, while the different trajectories displayed by the three sites appear related to site-specific variables controlling exposure to waves and winds. Exposed sites showed a lower ability to absorb disturbances and a greater range of system responses, varying between transgressive and progradational states.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121894
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1895: Marine Ancillary Diesel Engine Emissions
           Reduction Using Advanced Fuels

    • Authors: Michal Puškár, Pavol Tarbajovský, Matúš Lavčák, Marieta Šoltésová
      First page: 1895
      Abstract: Large transoceanic ships use marine ancillary diesel engines for generating electricity, which, on the other hand, produce a remarkable amount of harmful emissions during the combustion process. The International Maritime Organisation (IMO) establishes standards that limit the amount of harmful emissions produced during the engine combustion cycle in maritime transport. Because of this restriction, new alternative fuels entered the market. Experiments had been performed with various testing fuels created from biodiesel and ULSD-F (Ultra Low Sulphur Diesel-Fuel) in the ratios of 0%, 50%, 80%, and 100%. During the tests, the engine ran at different speeds and loads so that the mixed fuel influence on engine operation could be observed in detail and investigated.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121895
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1896: Efficiency and Wave Run-Up of Porous Breakwater
           with Sloping Deck

    • Authors: Mengmeng Han, Chien Ming Wang
      First page: 1896
      Abstract: In order to protect fragile shoreline and coastal assets during extreme storms, a combined floating breakwater-windbreak has been proposed to reduce both wind and wave energies in the sheltered area. The 1 km-long breakwater has a porous hull with internal tubes to allow free passage of water; thereby further dissipating wave energy. The deck of the structure is designed to have a slope of 25 degrees facing the upstream side, and arrays of cylindrical tubes are placed on the sloping deck to form a windbreak. A reduced-scale (1:50) model test was carried out in a wave flume to examine wave sheltering performance under significant wave heights Hs = 3.0 m to 7.5 m and peak wave periods Tp = 9.4 s to 14 s sea states. Both regular and random wave conditions with different wave heights were considered. It is found that transmission coefficients ranging from 0.4 to 0.6 can be achieved under tested wave conditions. Porous breakwater hull increases the wave dissipation coefficients and is effective in reducing the wave reflection at the upstream side. The wave run-up length is dependent on the Iribarren number if the reduction induced by vertical freeboard is considered. Based on experimental data, empirical formulae have been proposed to predict the wave run-up responses in regular waves, probability of non-zero wave run-up occurrence, modified Weibull distribution of the wave run-up peaks and extreme wave run-up in random waves.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121896
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1897: A Na+/H+-Exchanger Gene from Penaeus monodon:
           Molecular Characterization and Expression Analysis under Ammonia Nitrogen
           Stress

    • Authors: Yundong Li, Shigui Jiang, Hongdi Fan, Qibin Yang, Song Jiang, Jianhua Huang, Lishi Yang, Wenwen Zhang, Xu Chen, Falin Zhou
      First page: 1897
      Abstract: Na+/H+-exchanger (NHE) assumes a significant part in different particle transport in creatures. A clone of Penaeus monodon NHE cDNA was examined in this study (PmNHE), and its impact on high-concentration ammonia nitrogen stress was researched. The 877-amino acid (aa) protein was encoded by a full-length PmNHE cDNA that was 2788 base pairs (bp) long and had a 2643-bp open reading frame (ORF). The findings show that PmNHE was expressed in all of the P. monodon organs that were tested, including the intestine, muscle, hemolymph, heart, hepatopancreas, stomach, epidermis, gill, testis, and ovary, and the intestine and muscle were found to have the highest levels of PmNHE expression. The expression of PmNHE in the gill tissue of P. monodon was significantly up-regulated under high levels of ammonia nitrogen stress. The expression of PmNHE in the intestine of P. monodon under high-concentration ammonia nitrogen stress was significant. When exposed to high concentrations of ammonia nitrogen stress, P. monodon exhibited shorter survival times than the two control groups. Hence, it is suggested in the present study that PmNHE may have a significant impact on the environment with high levels of ammonia nitrogen.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121897
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1898: An Open-Source Benchmark Simulator: Control of
           a BlueROV2 Underwater Robot

    • Authors: Malte von Benzon, Fredrik Fogh Sørensen, Esben Uth, Jerome Jouffroy, Jesper Liniger, Simon Pedersen
      First page: 1898
      Abstract: This paper presents a simulation model environment for the popular and low-cost remotely operated vehicle (ROV) BlueROV2 implemented in Simulink™ which has been designed and experimentally validated for benchmark control algorithms for underwater vehicles. The BlueROV2 model is based on Fossen’s equations and includes a kinematic model of the vehicle, the hydrodynamics of vehicle and water interaction, a dynamic model of the thrusters, and, lastly, the gravitational/buoyant forces. The hydrodynamic parameters and thruster model have been validated in a test facility. The benchmark model also includes the ocean current, modeled as constant velocity. The tether connecting the ROV to the top-site facility has been modeled using the lumped mass method and is implemented as a force input to the ROV model. At last, to show the usefulness of the benchmark model, a case study is presented where a BlueROV2 is deployed to inspect an offshore monopile structure. The case study uses a sliding mode controller designed for the BlueROV2. The controller fulfills the design criteria defined for the case study by following the provided trajectory with a low error. It is concluded that the simulator establishes a benchmark for future control schemes for position control and trajectory tracking under the influence of environmental disturbances.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121898
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1899: Predicting the Motion of a USV Using Support
           Vector Regression with Mixed Kernel Function

    • Authors: Pengfei Xu, Qingbo Cao, Yalin Shen, Meiya Chen, Yanxu Ding, Hongxia Cheng
      First page: 1899
      Abstract: Predicting the maneuvering motion of an unmanned surface vehicle (USV) plays an important role in intelligent applications. To more precisely predict this empirically, this study proposes a method based on the support vector regression with a mixed kernel function (MK-SVR) combined with the polynomial kernel (PK) function and radial basis function (RBF). A mathematical model of the maneuvering of the USV was established and subjected to a zig-zag test on the DW-uBoat USV platform to obtain the test data. Cross-validation was used to optimize the parameters of SVR and determine suitable weight coefficients in the MK function to ensure the adaptive adjustment of the proposed method. The PK-SVR, RBF-SVR, and MK-SVR methods were used to identify the dynamics of the USV and build the corresponding predictive models. A comparison of the results of the predictions with experimental data confirmed the limitations of the SVR with a single kernel function in terms of forecasting different parameters of motion of the USV while verifying the validity of the MK-SVR based on data collected from a full-scale test. The results show that the MK-SVR method combines the advantages of the local and global kernel functions to offer a better predictive performance and generalization ability than SVR based on the nuclear kernel function. The purpose of this manuscript is to propose a novel method of dynamics identification for USV, which can help us establish a more precise USV dynamic model to design and verify an excellent motion controller.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121899
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1900: An Underwater Inductive Power Transfer System
           with a Compact Receiver and Reduced Eddy Current Loss

    • Authors: Zhengchao Yan, Chenxu Zhao, Qianyu Hu, Min Wu, Lin Qiao, Kehan Zhang, Yuli Hu
      First page: 1900
      Abstract: Inductive power transfer (IPT) technology is widely used in autonomous underwater vehicles (AUVs) to achieve safety and flexibility. However, the eddy current loss (ECL) will be generated in the seawater due to the high-frequency alternating current in the transmitter and receiver. An underwater IPT system with a series-none (SN) compensation topology is proposed in this paper to achieve a compact receiver for AUVs and reduce the ECL. The analytical model of the IPT system is built to analyze its transfer performance. The phase difference between the transmitter and receiver current of the SN compensation topology is larger than 90° compared to that of the conventional series-series (SS) topology, which can significantly decrease the magnitude of the electric field caused by coil currents; thus, the eddy current loss is reduced. Moreover, the optimal load resistance of the seawater IPT system is lower than that in the air, and the SN compensation topology has a more compact receiver with no compensation capacitor in the receiving side, which can save the internal space in the AUVs. An experimental prototype based on the SN topology is built, and the experimental results have verified the analysis.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121900
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1901: An Evaluation of Marine Renewable Energy
           Resources Complementarity in the Portuguese Nearshore

    • Authors: Florin Onea, Eugen Rusu
      First page: 1901
      Abstract: The Portuguese nearshore represents a suitable environment for the development of marine energy farms, with recent progress being related to the implementation of the first commercial wave farm or a large scale floating wind project. At the same time, there is also high solar power in this area that can be extracted; in the near future, the rapid development of floating solar projects all over the world is expected. In this context, the aim of the present work is to identify the complementarity between solar, wind and wave resources based on 10 years of ERA5 data (from 2012 to 2021). The results are provided mainly in terms of spatial maps. The analysis shows that solar and wind power are more significant in the southern part of this region, indicating for each resource an average value of 223 W/m2 for solar and 660 W/m2 for wind. On the other hand, the wave power gradually decreases from north to south, with an average value of 10 kW/m being expected at a distance of 50 km from the shoreline. In terms of complementarity, two scenarios were considered (mild and restrictive), the difference between them being estimated to be around 10%. Several dimensionless indices were defined in order to highlight the correlation between solar, wind and wave conditions, which may be considered as an element of novelty for the target area. In general, higher values (0.5) were noted in the case of the wind-wave and wave-solar combinations, excepting the southern part of Portugal (Algarve) where particular conditions were noted. Finally, the expected power outputs from some relevant technologies were also estimated, including a new concept of the wave energy generator designed for the WindFloat platform. Compared to the solar and wind systems, the performance of the selected wave generation system was quite low, suggesting that other types of wave energy converters would be more appropriate at this moment in the coastal area targeted. Finally, we need to mention that the idea of using multiple resources from a single marine site is an attractive one, while the methodology dedicated to this topic will continuously improve as new technological solutions emerge.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121901
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1902: Calibration and Validation of Two Tidal Sand
           Wave Models:A Case Study of The Netherlands Continental Shelf

    • Authors: G. H. P. Campmans, Thaienne A. G. P. van Dijk, Pieter C. Roos, Suzanne J. M. H. Hulscher
      First page: 1902
      Abstract: Tidal sand waves form a dynamic bed pattern, widely occurring in shallow shelf seas such as the North Sea. Their importance to coastal engineering has inspired many advances in process-based sand wave modelling, aimed at explaining physical mechanisms in the formation stage (‘linear regime’) and capturing the finite amplitude evolution to equilibrium states (‘nonlinear regime’). However, systematic validation of particularly the nonlinear sand wave models is still lacking. Here, we perform a two-step calibration and validation study of a sand wave model (specifically, their linear and nonlinear model versions) against field data from the North Sea. In the first step, the linear model is calibrated by seeking overall values of two uncertain input parameters (slip parameter, wave period) for which the modeled and observed wavelengths show the best agreement. In the second step, using the calibrated input parameters and preferred wavelengths from the linear model, equilibrium heights from the nonlinear sand wave model are validated against the observed sand wave heights. Our results show satisfactory agreement between observed and modeled sand wave lengths (from the linear sand wave model) and a systematic overprediction of sand wave heights (using the nonlinear model). Regression analysis can be used to rescale the nonlinear model results to obtain realistic predictions of sand wave heights.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121902
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1903: An Approach to Accurate Ship Image Recognition
           in a Complex Maritime Transportation Environment

    • Authors: Meng Yu, Shaojie Han, Tengfei Wang, Haiyan Wang
      First page: 1903
      Abstract: In order to monitor traffic in congested waters, permanent video stations are now commonly used on interior riverbank bases. It is frequently challenging to identify ships properly and effectively in such images because of the intricate backdrop scenery and overlap between ships brought on by the fixed camera location. This work proposes Ship R-CNN(SR-CNN), a Faster R-CNN-based ship target identification algorithm with improved feature fusion and non-maximum suppression (NMS). The SR-CNN approach can produce more accurate target prediction frames for prediction frames with distance intersection over union (DIOU) larger than a specific threshold in the same class weighted by confidence scores, which can enhance the model’s detection ability in ship-dense conditions. The SR-CNN approach in NMS replaces the intersection over union (IOU) filtering criterion, which solely takes into account the overlap of prediction frames, while DIOU, also takes into account the centroid distance. The screening procedure in NMS, which is based on a greedy method, is then improved by the SR-CNN technique by including a confidence decay function. In order to generate more precise target prediction frames and enhance the model’s detection performance in ship-dense scenarios, the proposed SR-CNN technique weights prediction frames in the same class with DIOU greater than a predetermined threshold by the confidence score. Additionally, the SR-CNN methodology uses two feature weighting methods based on the channel domain attention mechanism and regularized weights to provide a more appropriate feature fusion for the issue of a difficult ship from background differentiation in busy waters. By gathering images of ship monitoring, a ship dataset is created to conduct comparative testing. The experimental results demonstrate that, when compared to the three traditional two-stage target detection algorithms Faster R-CNN, Cascade R-CNN, and Libra R-CNN, this paper’s algorithm Ship R-CNN can effectively identify ship targets in the complex background of far-shore scenes where the distinction between the complex background and the ship targets is low. The suggested approach can enhance detection and decrease misses for small ship targets where it is challenging to distinguish between ship targets and complex background objects in a far-shore setting.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121903
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1904: Marine Radar Oil Spill Extraction Based on
           Texture Features and BP Neural Network

    • Authors: Rong Chen, Baozhu Jia, Long Ma, Jin Xu, Bo Li, Haixia Wang
      First page: 1904
      Abstract: Marine oil spills are one of the major threats to marine ecological safety, and the rapid identification of oil films is of great significance to the emergency response. Marine radar can provide data for marine oil spill detection; however, to date, it has not been commonly reported. Traditional marine radar oil spill research is mostly based on grayscale segmentation, and its accuracy depends entirely on the selection of the threshold. With the development of algorithm technology, marine radar oil spill extraction has gradually come to focus on artificial intelligence, and the study of oil spills based on machine learning has begun to develop. Based on X-band marine radar images collected from the Dalian 716 incident, this study used image texture features, the BP neural network classifier, and threshold segmentation for oil spill extraction. Firstly, the original image was pre-processed, to eliminate co-channel interference noise. Secondly, texture features were extracted and analyzed by the gray-level co-occurrence matrix (GLCM) and principal component analysis (PCA); then, the BP neural work was used to obtain the effective wave region. Finally, threshold segmentation was performed, to extract the marine oil slicks. The constructed BP neural network could achieve 93.75% classification accuracy, with the oil film remaining intact and the segmentation range being small; the extraction results were almost free of false positive targets, and the actual area of the oil film was calculated to be 42,629.12 m2. The method proposed in this paper can provide a reference for real-time monitoring of oil spill incidents.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121904
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1905: Study on Impact Load and Head Cap Load
           Reduction Performance of Vehicle Entering Water at High Speed

    • Authors: Hairui Zhao, Yao Shi, Guang Pan, Qiaogao Huang
      First page: 1905
      Abstract: Aiming at the problem of high-speed entry of vehicles with a diameter of 200 mm, a numerical model of high-speed entry of vehicles is established based on the arbitrary Lagrange–Euler (ALE) algorithm, and the numerical simulation of high-speed entry of flat-nosed and round-nosed vehicles is carried out. On this basis, the experimental research on the entry of vehicle with buffer caps is carried out. The following conclusions are obtained through simulation. The peak value of the axial load of the vehicle raises with the increase of the inlet velocity and angle, while the stable value only raises with the increase of the inlet velocity. The impact load on the round-nosed vehicle is obviously smaller than that on the flat-nosed vehicle when the water entry angle is greater than 80°. The peak value of axial load can be reduced by 22% when entering water vertically at 100 m/s. The following conclusions are obtained through experiments. The buffer head cap has a significant load reduction effect. It shows compaction, cracks and breakage under the impact of water. These processes can absorb part of the impact energy, reduce the peak value of axial load and increase the pulse width. The load reduction rate grows from 4.7% to 18.5% when the length of the buffer head cap is increased from 200 mm to 300 mm while the water inlet speed is the same. The damage level of the head cap increases sharply, and the load reduction rate raises when the water entry speed is increased while the length of the buffer head cap is the same.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121905
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1906: A Cost–Benefit Approach to Discuss
           Artificial Nourishments to Mitigate Coastal Erosion

    • Authors: Carlos Coelho, Márcia Lima, Margarida Ferreira
      First page: 1906
      Abstract: Worldwide, artificial nourishments are being considered as one of the main coastal erosion mitigation measures. However, this solution is not permanent, since the natural removal of sediments that occurs after the sand deposition leads to the need of re-nourishment projects; thus, its performance and longevity dependent on several design parameters (placement site and extension alongshore, frequency, and volume, etc.) In this work, a methodological approach for cost–benefit assessment is applied to analyze the performance of artificial nourishments from a physical and economical point of view, by analyzing the effectiveness of different scenarios. The study was developed considering two study areas: a hypothetical situation (generic study area) and a real coastal stretch (Barra-Vagueira, located in the Portuguese west coast). The findings show the complexity in defining the best nourishment option, being dependent on the wave climate, site specific conditions, and main goal of the intervention. The proposed cost–benefit approach allows one to obtain and compare the physical and economic performance of artificial nourishments to mitigate coastal erosion, aiding the decision-making processes related to coastal planning and management.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121906
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1907: Dynamic Response of a SPAR-Type Floating Wind
           Turbine Foundation with Taut Mooring System

    • Authors: Gong Xiang, Xianbo Xiang, Xiaochuan Yu
      First page: 1907
      Abstract: Compared with the traditional catenary or semi-taut mooring lines, the taut mooring system is more advantageous in many aspects, such as reduction of mooring line loads, erosion and fatigue damage during the powering productions of the floating wind turbines. This paper presents a taut mooring system made of synthetic fiber mooring lines, which can experience large elongations for a spar-type floating wind turbine. A finite element method (FEM)-based tensile mooring line model is proposed to study the mooring statics and dynamics of the floating wind turbine. A time domain modelling method coupled with the developed mooring line model is adopted to study the dynamics of a spar-type floating wind turbine foundation moored by the taut mooring system under regular waves. A systematic dynamic response and structural analysis are conducted based on variations in the mooring length and pretension. Additionally, comparative performance analyses are investigated for two mooring configurations with different numbers of mooring lines: two-point and three-point taut mooring system. It is found that factors, such as mooring length, pretension and the number of mooring lines, have significant impact on the in-plane and out-of-plane motion responses of the foundation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121907
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1908: Application and Validation of an Ecological
           Quality Index, ISEP, in the Yellow Sea

    • Authors: Jae-Won Yoo, Yong-Woo Lee, Mi-Ra Park, Chang-Soo Kim, Sungtae Kim, Chae-Lin Lee, Su-Young Jeong, Dhongil Lim, Sung-Yong Oh
      First page: 1908
      Abstract: An ecological index of macrobenthic communities is an important tool for assessing the biological quality of habitats and ecosystems. We tested the performance of the inverse function of the Shannon–Wiener evenness proportion (ISEP) with data from the entire west coast of Korea, seasonally sampled from 2006 to 2008. Two validations were performed: (1) examination of the relationship between ISEP and environmental factors and (2) correspondence between the ISEP and the Pearson–Rosenberg (P-R) model for the species-abundance-biomass (SAB) patterns and taxonomical variations. The ISEP was significantly correlated with suspended solids but independent of other natural habitat conditions due to their low to moderate contamination levels. From this, ISEP performed as expected in transitional zones of low salinity and applications across habitats of various sediments. The SAB patterns and taxonomic variations along the ISEP grades showed marked similarities to the P-R model. The only departure was biomass, which increased after the normal status. The increase was interpreted as reflecting a healthier and more mature status. Taxonomic variation patterns and the taxa composition that characterized either poor or healthy status corresponded well with the P-R model. The conformity to the P-R model indicates the capability and potential applicability of the ISEP to other coastal systems.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121908
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1909: Speleothems and Biomineralization Processes in
           Hot Spring Environment: The Case of Aedipsos (Edipsos), Euboea (Evia)
           Island, Greece

    • Authors: Kanellopoulos, Lamprinou, Politi, Voudouris, Iliopoulos, Kokkaliari, Moforis, Economou-Amilli
      First page: 1909
      Abstract: Caves with hot springs and speleothem deposits are infrequent environments of high scientific interest due to their unique environmental conditions. The selected site is a small open cave with a hot spring and stalactites in the Aedipsos area (NW Euboea Island, Greece), which was studied through an interdisciplinary approach. The mineralogical composition of the speleothems was determined by optical microscopy, XRD, and SEM-EDS microanalysis, and identification of the Cyanobacteria species was made based on morphological characteristics. The main mineral phase in the studied samples is calcite, with several trace elements (i.e., up to 0.48 wt.% Na2O, up to 0.73 wt.% MgO, up to 4.19 wt.% SO3, up to 0.16 wt.% SrO and up to 2.21 wt.% Yb2O3) in the mineral-chemistry composition. The dominant facies are lamination and shrubs, which are the most common among the facies of the thermogenic travertines of the area. Based on the studied stalactites, twenty-nine different Cyanobacteria species were identified, belonging to the following orders: Synechococcales (28%), Oscillatoriales (27%), Chroococcales (21%) and Nostocales (21%), and Spirulinales (3%). Among them, thermophilic species (Spirulina subtilissima) and limestone substrate species (Chroococcus lithophilus, Leptolyngbya perforans, and Leptolyngbya ercegovicii) were identified. The identified Cyanobacteria were found to participate in biomineralization processes. The most characteristic biomineralization activity is made by the endolithic Cyanobacteria destroying calcite crystals in the outer layer. In a few cases, calcified cyanobacterial sheaths were detected. The presence of filamentous Cyanobacteria, along with extracellular polymeric substance (EPS), creates a dense net resulting in the retention of calcium carbonate crystals.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121909
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1910: Experimental Analysis of CENTEC-TLP Self-Stable
           Platform with a 10 MW Turbine

    • Authors: Mohamad Hmedi, Emre Uzunoglu, Antonio Medina-Manuel, Jordi Mas-Soler, Felipe Vittori, Oscar Pires, José Azcona, Antonio Souto-Iglesias, C. Guedes Soares
      First page: 1910
      Abstract: This work evaluates the experimental test results regarding the operational performance of a free-float capable tension leg platform with a 10 MW wind turbine. It covers the platform dynamics in the selected installation area: Ribadeo, Spain. The model and the facility are initially presented, along with the experimental setup and the load cases. The testing campaign includes a software-in-the-loop method to emulate the rotor thrust and the aerodynamic and gyroscopic moments in pitch and yaw. The result sets are structured to start from basic information from system identification cases and continue with responses against regular and irregular waves accompanied by steady and stochastic wind scenarios. The performance in operational and extreme conditions is assessed as well as fault scenarios. The experiments demonstrate auspicious motion dynamics and mooring line behavior when examined against class society rules.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121910
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1911: Influence of Tsunami-Driven Shipping
           Containers’ Layout on Their Motion

    • Authors: Yudou Hou, Tomoaki Nakamura, Yong-Hwan Cho, Norimi Mizutani, Takashi Tomita
      First page: 1911
      Abstract: This study investigated the interaction between containers under extreme hydrodynamic conditions modeled on tsunamis to assess whether the number and layout of containers affect their motion and to guide future studies on numerical simulations describing tsunami-debris motion. The three-dimensional Fluid–Structure–Sediment–Seabed Interaction Model (FS3M), which can compute tsunami–container interaction, was used as a numerical test model, and numerical results for the specific target of the simulation were compared with experimental data to check the validity and computational accuracy of the FS3M. The study showed that the number of rows (Nx), columns (Ny), and stacks (Nz) in the initial arrangement of containers constitute the main factor affecting the area where the containers spread and their drift motion velocity. An increase in Nx and Nz can effectively reduce the container drift velocity. Conversely, as Ny increases, the drift motion velocity of the center of gravity of the entire group increases. The results of this study can facilitate the development of more realistic building structure scenarios in future research that consider the proposed characteristic damage estimation and comprehensive assessment methods laid out herein.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121911
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1912: Increase in the Erosion Rate due to the Impact
           of Climate Change on Sea Level Rise: Victoria Beach, a Case Study

    • Authors: Maria Aguilera-Vidal, Juan J. Muñoz-Perez, Antonio Contreras, Francisco Contreras, Patricia Lopez-Garcia, Bismarck Jigena
      First page: 1912
      Abstract: This article provides a general methodology for calculating the retreat of the coastline and the volume of sand necessary to renourish a beach due to sea level rise (SLR) in the medium-long term. An example is presented, Victoria Beach, and a projection is made for the years 2030, 2040, 2050, and 2100. The results obtained take into account global sea level rise (GSLR), which is worldwide, and local sea level rise (LSLR), which considers climate variability and vertical land movements. Regarding GSLR, data were provided by the projections from IPCC (Intergovernmental Panel on Climate Change) scenarios and empirical models, such as Rahmstorf and Pfeffer. The LSLR data came from the tide gauge station located in Cadiz. Finally, the results obtained showed that global warming impacts erosive effects and the subsequent volume of sand required to renourish beaches. The total sea level rise (TSLR) projections indicated for Victoria Beach are relatively higher than the GSLR projections. Even in the best IPCC scenario (RCP 2.6), Victoria Beach presents a significant erosion of 52 m, requiring a volume of sand of 1.0 Mm3 to supply renourishment.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121912
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1913: Numerical Investigation of Vortex Shedding from
           a 5:1 Rectangular Cylinder at Different Angles of Attack

    • Authors: Jian Wu, Yakun Liu, Di Zhang, Ze Cao, Zijun Guo
      First page: 1913
      Abstract: Although flow around a 5:1 rectangular cylinder at small angles of attack (AoA) has been extensively studied, when the AoA becomes larger, the research is rare. Therefore, this study performs Unsteady Reynolds-Averaged Navier-Stokes simulations (URANS) using the k-ω SST turbulence model for unsteady flow around a two-dimensional 5:1 rectangular cylinder at different AoAs up to 45°. A strong dependence of the flow characteristics on AoA is observed through the analysis of the time-averaged lift coefficient, drag coefficient, and Strouhal number. The peak of lift and drag coefficient is observed to be correlated, respectively, to the leading- and trailing-edge vortex based on the analysis of the flow. The x′-directional length of the main recirculation bubble on the top side and the distance from the bubble center to the leading edge of the cylinder both reach the maximum when α = 15°. In addition, the standard deviation σx' of the time-averaged velocity U¯x' along the cylinder shows a trend of increasing at first and then decreasing, and that σy' also shows the same trend at α = 20°~45°; it fluctuates within a range of 0.05~0.2 at α = 0°~20°. Finally, two principal modes of vortex shedding are observed with α = 15° being their turning point, (i) “1 + 1” mode: in one vortex shedding period, two major vortices shed off from the top and bottom sides of the cylinder at α ≤ 15°; (ii) “2 + 2” mode, four vortices shed off from the top and bottom sides of the cylinder at α > 15° in one vortex shedding period.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121913
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1914: Dynamic Modeling of Underwater Snake Robot by
           Hybrid Rigid-Soft Actuation

    • Authors: Junhao Zhang, Yinglong Chen, Yi Liu, Yongjun Gong
      First page: 1914
      Abstract: For decades, underwater vehicles have been performing underwater operations, which are critical to the development and upgrading of underwater robots. With the advancement of technology, various types of robots have been developed. The underwater robotic snake is a bioinspired addition to the family of underwater robotic vehicles. In this paper, we propose an innovative underwater snake robot actuated by rigid propulsions and soft joints, which can improve the swimming efficiency and flexibility of the robot and reduce the probability of collision leading to damage. Existing math models of robotic snakes typically incorporate only planar motion, rarely considering spatial motion. So, we formulate a complete three-dimensional dynamic model for the robotic snake, which is extended by deriving expressions for the geometric Jacobians. This modeling approach is well suited since it provides compact matrix expressions and easy implementation. We use the constant curvature method to describe the configuration of the soft joint, use the Lagrangian method to obtain its dynamic characteristics, and focus on deriving the visco-hyperelastic mechanical energy of the soft material. Next, the local dynamics of soft members are extended as a nonholonomic constraint form for modeling the snake robot. Finally, the multi-modal swimming behavior of the robot has been verified by simulations, including forward and backward rectilinear motion, yaw turning, pitch motion, and spiral rising motion. The overall results demonstrate the effectiveness and the versatility of the developed dynamic model in the prediction of the robot trajectory, position, orientation, and velocity.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-05
      DOI: 10.3390/jmse10121914
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1915: DNA Barcoding Is a Useful Tool for the
           Identification of the Family Scaridae in Hainan

    • Authors: Bo Liu, Yali Yan, Nan Zhang, Huayang Guo, Baosuo Liu, Jingwen Yang, Kecheng Zhu, Dianchang Zhang
      First page: 1915
      Abstract: Species markers can be quickly and accurately assessed using DNA barcoding. We investigated samples from the parrotfish family Scaridae using DNA barcoding in Hainan. A total of 401 DNA barcodes were analyzed, including 51 new barcodes generated from fresh material, based on a 533 bp fragment of the cytochrome c oxidase subunit I (CO I) gene. There were 350 CO I barcode clusters that matched 43 species from the Barcode of Life Data Systems (BOLD) and GenBank databases. The results showed the following average nucleotide compositions for the complete dataset: adenine (A, 22.7%), thymine (T, 29.5%), cytosine (C, 29.5%), and guanine (G, 18.2%). The mean genetic distance between confamilial species was nearly 53-fold greater than that between individuals within the species. In the neighbor-joining tree of CO I sequences, Chlorurus sordidus and C. spilurus clustered together, and all other individuals clustered by species. Our results indicated that DNA barcoding could be used as an effective molecular tool for monitoring, protecting, and managing fisheries, and for elucidating taxonomic problem areas that require further investigation.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121915
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1916: Lateral Export and Sources of Subsurface
           Dissolved Carbon and Alkalinity in Mangroves: Revising the Blue Carbon
           Budget

    • Authors: Daniel M. Alongi
      First page: 1916
      Abstract: Mangroves are carbon-rich ecosystems that store large quantities of carbon, mostly in soils. Early carbon (C) budgets indicated that >50% of mangrove C fixation was unaccounted for. This ‘missing C’ has now been discovered to be a large release (423 Tg C a−1) of porewater dissolved DIC (dissolved inorganic carbon), dissolved organic carbon (DOC), and total alkalinity (17 TMOL a−1) via lateral export derived from bacterial decomposition of soil organic matter. This large export originates from DIC produced over at least a 1.0–1.5 m soil profile (280–420 Tg C a−1) via decomposition of autochthonous and allochthonous inputs and/or likely mineralization in deep (≥1 m) ancient soils. DOC and DIC export from mangroves equate to 41% and ≈100% of export from the world’s tropical rivers, respectively. A newly revised blue carbon budget for the world’s mangroves indicates a mean ecosystem gross primary production (GPPE) to ecosystem respiration (RE) ratio of 1.35 and a net ecosystem production (NEP) of 794 g C m−2 a−1 (= global NEP of 117 Tg C a−1), reflecting net autotrophy. CORG burial is 5% and 9% of GPPE and NEPE, respectively. Mean RE/GPPE is 0.74 and carbon use efficiency averages 0.57, higher than for tropical humid forests (0.35).
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121916
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1917: Initiating a DNA Barcoding Reference Library of
           Stony Corals from the Gulf of Eilat (Red Sea)

    • Authors: Elad Nehoray Rachmilovitz, Omri Shabbat, Maayan Yerushalmy, Baruch Rinkevich
      First page: 1917
      Abstract: Accurate identification of scleractinian coral species is fundamental for proper biodiversity estimates, for aiding in efforts of reef monitoring, conservation, restoration, and for the management of coral reefs. Here, we provide the first DNA barcoding reference library for coral species in Eilat, Red Sea, based on the mitochondrial gene cytochrome c oxidase subunit I (COI), targeting the identification of stony coral species from shallow (0–12 m) reefs. A total of 191 specimens were collected, depicting 14 families, 39 genera, and 94 species (all are new full species records to the BOLD system). Three species (Sclerophyllia margariticola, Cyphastrea magna, and Psammocora profundacella) are first records for Eilat’s coral reef. The results presented here strengthen the claim that COI is not universally informative for delimitation of stony coral species, a notion reinforced by the constructed maximum likelihood phylogenetic tree. This library is the first step in a long journey towards elucidating coral biodiversity in the coral reef at Eilat and for improving future management and monitoring efforts.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121917
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1918: Acoustic Response of a Vibrating Elongated
           Cylinder in a Hydrodynamic Turbulent Flow

    • Authors: Giacomo Rismondo, Marta Cianferra, Vincenzo Armenio
      First page: 1918
      Abstract: The present paper contains the results of the numerical analysis of the interaction between a Newtonian incompressible turbulent flow and a linear elastic slender body, together with the influence of the fluid–structure interaction (FSI) on the noise generation and propagation. The purpose is to evaluate the differences in term of acoustic pressure between the case where the solid body is rigid (infinite stiffness) and the case where it is elastic (finite stiffness). A partitioned and implicit algorithm with the arbitrary Lagrangian–Eulerian method (ALE) is used for the interaction between the fluid and solid. For the evaluation of the turbulent fluid motion, we use a large eddy simulation (LES) with the Smagorinsky subgrid scale model. The equation for the solid is solved through the Lagrangian description of the momentum equation and the second Piola–Kirchoff stress tensor. In addition, the acoustic analogy of Lighthill is used to characterize the acoustic source (the slender body) by directly using the fluid dynamic fields. In particular, we use the Ffowcs Williams and Hawkings (FW-H) equation for the evaluation of the acoustic pressure in the fluid medium. As a first numerical experiment, we analyze a square cylinder immersed in a turbulent flow characterized by two different values of stiffness: one infinite (rigid case) and one finite (elastic case). In the latter case, the body stiffness and mean flow velocity are such that they induce the lock-in phenomenon. Finally, we evaluate the differences in terms of acoustic pressure between the two different cases.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121918
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1919: Prediction of Operation Time of Container Ship
           at Berth under Uncertain Factors Based on a Hybrid Model Combining PCA and
           ELM Optimized by IPSO

    • Authors: Zhaohui Li, Lin Wang, Wenjia Piao, Hao Jia, Shan Dong, Jiehan Zhang
      First page: 1919
      Abstract: With the rapid development of global trade, the turnover of shipping containers has increased rapidly. How to use port resources reasonably and efficiently has become one of the main challenges that ports need to deal with when planning for the future. In order to develop scientific and efficient berth plans to improve operational efficiency and service level, this paper proposes a hybrid prediction model based on Principal Component Analysis (PCA) and Extreme Learning Machine (ELM) optimized by Improved Particle Swarm Optimization (IPSO), namely, the PCA-IPSO-ELM model. After assessing the uncertain factors influencing the operation time of the container ship at berth, this work reduces the dimensionality of the investigational data by the PCA method. Aiming to solve easy premature convergence of the traditional particle swarm algorithm, this paper introduces an improved particle swarm optimization algorithm via dynamic adjustment of nonlinear parameters. This improved particle swarm algorithm is mainly used to optimize the weights and thresholds of the extreme learning machine. Thus, a PCA-IPSO-ELM model which aims to forecast the operation time of a container ship at berth, is constructed. Using the historical operation data of the Tianjin Port Container Shipping Company as the prediction sample, this PCA-IPSO-ELM model is compared and assessed with traditional models. The results show that compared with other models, the PCA-IPSO-ELM prediction model has the characteristics of high prediction accuracy, fast running rate and strong stability, and it has a higher coefficient of determination and a better fitting degree.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121919
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1920: Deep Learning-Based Signal Detection for
           Underwater Acoustic OTFS Communication

    • Authors: Yuzhi Zhang, Shumin Zhang, Bin Wang, Yang Liu, Weigang Bai, Xiaohong Shen
      First page: 1920
      Abstract: Orthogonal time frequency space (OTFS) is a novel two-dimensional (2D) modulation technique that provides reliable communications over time- and frequency-selective channels. In underwater acoustic (UWA) channel, the multi-path delay and Doppler shift are several magnitudes larger than wireless radio communication, which will cause severe time- and frequency-selective fading. The receiver has to recover the distorted OTFS signal with inter-symbol interference (ISI) and inter-carrier interference (ICI). The conventional UWA OTFS receivers perform channel estimation explicitly and equalization to detect transmitted symbols, which requires prior knowledge of the system. This paper proposes a deep learning-based signal detection method for UWA OTFS communication, in which the deep neural network can recover the received symbols after sufficient training. In particular, it cascades a convolutional neural network (CNN) with skip connections (SC) and a bidirectional long short-term memory (BiLSTM) network to perform signal recovery. The proposed method extracts feature information from received OTFS signal sequences and trains the neural network for signal detection. The numerical results demonstrate that the SC-CNN-BiLSTM-based OTFS detection method performs with a lower bit error rate (BER) than the 2D-CNN, FC-DNN, and conventional signal detection methods.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121920
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1921: Heavy Metal Contamination and Ecological Risk
           Assessment in the Sediment Cores of the Wetlands in Southern Thailand

    • Authors: Siriporn Pradit, Prakrit Noppradit, Panisara Jitkaew, Karnda Sengloyluan, Thawanrat Kobkeatthawin, Araf Laerosa, Sanya Sirivithayapakorn
      First page: 1921
      Abstract: The concentration and distribution of trace metals were determined in sediment cores from the Khuan Khi Sian wetland, Thailand. The sediment cores were collected from seven stations in the dry and wet seasons in 2022. The concentration of Pb, As, and Cd in the dry season were in the range 0.00–60.16, 0.00–6.68, and 0.00–0.92 mg/kg (dry weight), respectively. Meanwhile, the concentration of Pb, As, and Cd in the wet season were in the range 0.00–12.12, 0.00–3.86, and 0.00–0.92 mg/kg (dry weight), respectively. The vertical profiles of metal concentrations in core sediment show a general increase from bottom to top. Average concentrations of heavy metals in the sediments of the Khuan Khi Sian wetland are found to be lower than the sediment quality guideline. In the sediment cores, only As in the dry season exceeded the U.S. EPA standard. The calculated enrichment factor (EF) and the geoaccumulation index (Igeo) indicate that the sediments were moderately polluted with As in some locations. According to the Ri analysis, Pb was low risk but the criteria of ecological risk of As and Cd are considerable and they are considered high risk. This is potentially due to agricultural activities and land use around the wetland areas and municipalities. The concentration of As and Cd should be of concern and subject to regular monitoring.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121921
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1922: Experimental Study on the Target–Receiver
           Formation Problem with the Exploitation of Coherent and Non-Coherent
           Bearing Information

    • Authors: Lu Wang, Shiliang Fang, Yixin Yang, Xionghou Liu
      First page: 1922
      Abstract: Localization of emitting sources is a fundamental task in sonar applications. One of the most important factors that affect the localization performance is the sensor–target geometry. The sensor formation problem is usually addressed in related work assuming that the target is static and the location is known to a certain degree, but this is not the case for many underwater surveillance problems. In this paper, we deal with the target–receiver formation problem from a different perspective, and propose to investigate the effect of target–receiver geometry on localization performance by exploiting the spatial spectrum of the direct position determination (DPD) methods. For a given multi-array system, the transformation of geometrical patterns can be explicitly demonstrated as the target moves along the track. Meaningful characteristics of the DPD methods are obtained from the experimental results, where coherent and non-coherent bearing information is used and compared. The feasibility of the DPD approaches in the ocean environments is also investigated by comparing with a matched filter processing (MFP)-based multi-array processor in order to validate the credibility of the results in this paper.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121922
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1923: Spectral Acoustic Fingerprints of Sand and
           Sandstone Sea Bottoms

    • Authors: Uri Kushnir, Vladimir Frid
      First page: 1923
      Abstract: Modern studies which dealt with the frequency domain analysis showed that a frequency-domain approach has an essential advantage and mentioned an inner qualitative relationship between the subsurface structure and its frequency spectra. This paper deals with the acoustic spectral response of sand and sandstone sediments at the sea bottom. An acoustic data collection campaign was conducted over two sand sites and two sandstone sites. The analysis of the results shows that reflections of acoustic signals from sand and sandstone sea bottom are characterized by various spectral features in the 2.75–6.75 kHz range. The differences in acoustic response of sand and sandstone can be quantified by examining the maximal normalized reflected power, the mean frequency, and the number of crossings at different power levels. The statistical value distribution of these potential classifiers was calculated and analyzed. These classifiers, and especially the roughness of the spectrum quantified by the number of crossings parameter can give information to assess the probability for sand or sandstone based on the reflected spectra and be used for actual distinction between sand and sandstone in sub bottom profiler data collection campaigns.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121923
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1924: Experimental Performance Analysis of a Hybrid
           Wave Energy Harvesting System Combining E-Motions with Triboelectric
           Nanogenerators

    • Authors: Daniel Clemente, Cátia Rodrigues, Ricardo Esteves, José Correia, André M. Pereira, João O. Ventura, Paulo Rosa-Santos, Francisco Taveira-Pinto, Paulo Martins
      First page: 1924
      Abstract: This paper discusses a disruptive approach to wave energy conversion, based on a hybrid solution: the E-Motions wave energy converter with integrated triboelectric nanogenerators. To demonstrate it, a physical modelling study was carried out with nine E-Motions sub-variants, which were based on three original hull designs (half-cylinder (HC), half-sphere (HS) and trapezoidal prism (TP)). A unidirectional lateral tribo-device was incorporated within the E-Motions’ hull during the experiments. The physical models were subjected to eight irregular sea-states from a reference study on the Portuguese coastline. Results point towards a significant hydrodynamic roll response, with peaks of up to 40 °/m. Three peaks were observed for the surge motions, associated with slow drifting at low frequencies. The response bandwidth of the HC sub-variants was affected by the varying PTO mass-damping values. By comparison, such response was generally maintained for all HS sub-variants and improved for the TP sub-variants, due to ballast positioning adjustments. Maximum power ratios ranged between 0.015 kW/m3 and 0.030 kW/m3. The TENGs demonstrated an average open-circuit voltage and power per kilogram ratio of up to 85 V and 18 mW/kg, respectively, whilst exhibiting an evolution highly dependent upon wave excitation, surge excursions and roll oscillations. Thus, TENGs enable redundant dual-mode wave energy conversion alongside E-Motions, which can power supporting equipment with negligible influence on platform hydrodynamics.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121924
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1925: Innovation in Smart Ports: Future Directions of
           Digitalization in Container Ports

    • Authors: Marikka Heikkilä, Jouni Saarni, Antti Saurama
      First page: 1925
      Abstract: New digital Industry 4.0 solutions and smart applications are being adopted in many industries, also in the most advanced ports in the world. Still, it is not clear in which directions digitalization in ports will develop in the future. Building on the research literature and the state-of-the-art in major container ports, this research characterizes smart ports and Port 4.0 with three key focus areas: automation, sustainability and collaboration. Following the scenario building theory, this article constructs four alternative scenarios for future smart ports and shows the ways in which these alternative scenarios will lead to different prioritization of digital innovations between automation, sustainable development and cooperation issues. This will have a big impact on what digitalization in ports will be like in the future.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121925
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1926: Design and Dynamic Analysis of a Novel
           Large-Scale Barge-Type Floating Offshore Wind Turbine with Aquaculture
           Cage

    • Authors: Yuting Zhai, Haisheng Zhao, Xin Li, Wei Shi
      First page: 1926
      Abstract: In this study, a novel large-scale barge-type floating offshore wind turbine with an aquaculture cage (LSBT-FOWT-AC) in a water depth of 100 m is designed through fully coupled analysis using the SESAM tool to support the Technical University of Denmark (DTU) 10 MW wind turbine. The intact stability and natural period of motion of the newly designed LSBT-FOWT-AC are evaluated based on the DNV rules and standards. Then, the dynamic responses of the LSBT-FOWT-AC under various sea conditions are studied. The motion of the LSBT-FOWT-AC platform is considerably affected by waves, and its motion response is within a reasonable range even under the extreme sea conditions of the 100-year return period. By analyzing the results of the out-of-plane bending moment of root of blade 1 (RootMyc1), it can be seen that the rotor frequency (1P) has a visible influence on the wind turbine. Through the analysis of dynamic response statistics of the LSBT-FOWT-AC structure by the single variable method of environmental loads, it is found that wind force exerts the greatest impact on the dynamic response compared to the wave-excitation force and current drag force.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121926
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1927: Characteristics and Driving Mechanisms of
           Salinity Stratification during the Wet Season in the Pearl River Estuary,
           China

    • Authors: Fang Yang, Xiaomei Ji, Wei Zhang, Huazhi Zou, Wenzhi Jiang, Yanwen Xu
      First page: 1927
      Abstract: In an estuary, stratification processes play a major role in inhibiting estuarine circulation, sediment transport, and the estuarine ecosystem. A detailed examination of the salinity stratification through the gradient Richardson number and the potential energy anomaly equation has been undertaken along the West Channel of the Pearl River Estuary, China. The results show that the estuarine circulation within the West Channel is much weaker on a spring tide than that on a neap tide, exhibiting apparent spring–neap tidal variability. The calculated gradient Richardson number displays its intratidal and spring–neap tidal variability within the West Channel, indicating the existence of intratidal and spring–neap tidal variability of stratification. In addition, the tidally averaged change rate of total potential energy anomaly within the West Channel suggests more than a 4.53 × 10−3 W·m−3 increase from spring to neap tides, demonstrating strong stratification on a neap tide. The longitudinal advection and the longitudinal depth-mean straining are the leading physical mechanisms contributing to intratidal and spring–neap variability of salinity stratification within the West Channel. However, the effects of the lateral terms cannot be ignored especially on a neap tide.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121927
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1928: Characteristic and Relative Environmental Risk
           of Disinfection by Products Associated with Simple Glucose or Naturally
           Occurring Algal Organic Matter as Tested in Ballast Water Treatment System
           

    • Authors: Pung-Guk Jang, Hyung-Gon Cha, Min-Chul Jang, Bonggil Hyun, Tae Seob Choi, Younseok Kang, Kyoungsoon Shin
      First page: 1928
      Abstract: To prevent the invasion of alien species, the International Maritime Organization and the United States Costal Guard require that a ballast water management system (BWMS) be installed on ships to treat the ballast water before discharging it. BWMS technologies use active substances, which create disinfection by-products (DBPs) during ballast water treatment. This study compared the characteristics of DBPs generated in the treatment of commercial glucose with those of algal organic matter (AOM) derived from field-collected phytoplankton using NaOCl as the active substance. During the treatment of AOM, a greater variety and higher concentrations of DBPs were generated than for glucose. For AOM in freshwater, bromoform and dibromoacetic acid were dominant because of the bromine ions present in the phytoplankton. During the treatment of glucose, the ratio of the predicted environmental concentration to the predicted no-effect concentration of dibromoacetonitrile and chloropicrin exceeded 1, indicating a potential environmental risk. Whole effluent toxicity (WET) testing showed that the chronic toxicity of phytoplankton and the total DBP concentration were highest in marine water with AOM. In addition, the results of WET testing suggested that the concentrations of haloacetic acids (HAAs) and haloacetonitriles (HANs) were important indicators for the evaluation of environmental risk. Therefore, to evaluate the risk of DBPs in international ports where phytoplankton outbreaks frequently occur, it is important to monitor not only the total DBP concentration but also the total HAA and HAN concentrations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121928
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1929: Influence of Inlets Morphology and Forcing
           Mechanisms on Water Exchange between Coastal Basins and the Sea: A
           Hindcast Study for a Mediterranean Lagoon

    • Authors: Irene Simonetti, Lorenzo Cappietti
      First page: 1929
      Abstract: A numerical model, validated with field measurements, was applied to comparatively reconstruct the hydrodynamics of a eutrophic coastal lagoon in a set of scenarios over the last two centuries. The effect of major morphological changes on the water exchange with the open sea and water residence time is evaluated. The results show that the number and morphology of the lagoon inlets are crucial in determining the volume of water exchanged with the sea, the water transport timescales, and the extent of poorly circulated stagnant areas with poor flushing potential, which are areas where anoxic crises might develop. When all the relevant forcing mechanisms on the hydrodynamics are considered, great variability of the water residence time is found in the different historical scenarios, with values varying between 83 and 305 days. The effect of anthropic actions on the system hydrodynamics was quantitatively evaluated, consolidating the background knowledge to support the present and future management of this environmental system.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121929
      Issue No: Vol. 10, No. 12 (2022)
       
  • JMSE, Vol. 10, Pages 1930: Defense Strategy against False Data Injection
           Attacks in Ship DC Microgrids

    • Authors: Hong Zeng, Yuanhao Zhao, Tianjian Wang, Jundong Zhang
      First page: 1930
      Abstract: False Data Injection Attacks (FDIA) on ship Direct Current (DC) microgrids may result in the priority trip of a large load, a black-out, and serious accidents of ship collisions when maneuvering in the port. The key of the prevention of FDIA is the detection of and countermeasures to false data. In this paper, a defense strategy is developed to detect and mitigate against FDIA on ship DC microgrids. First, a DC bus voltage estimator is trained with an Artificial Neural Network (ANN) model. The error between the estimate value and the measure value is compared with a threshold generated from history data to detect the occurrence of FDIA. Combined with the correlation of artificial neural network inputs, bad data are identified and recovered. The method is tested under six cases with different network and physical disturbances in Matlab/Simulink. The results show that the method can identify and mitigate the FDIA effectively; the error of identifying FDIA by ANN is less than 0.5 V. Therefore, the deviation between the actual bus voltage and the reference voltage is less than 0.5 V.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2022-12-06
      DOI: 10.3390/jmse10121930
      Issue No: Vol. 10, No. 12 (2022)
       
 
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