Journal of Marine Science and Engineering最新文献

{"title":"Temporal Scales of Mass Wasting Sedimentation across the Mississippi River Delta Front Delineated by 210Pb/137Cs Geochronology","authors":"Jeffrey Duxbury, Samuel J. Bentley, Kehui Xu, Navid H. Jafari","doi":"10.3390/jmse12091644","DOIUrl":"https://doi.org/10.3390/jmse12091644","url":null,"abstract":"The Mississippi River Delta Front (MRDF) is a subaqueous apron of rapidly deposited and weakly consolidated sediment extending from the subaerial portions of the Birdsfoot Delta of the Mississippi River, long characterized by mass-wasting sediment transport. Four (4) depositional environments dominate regionally (an undisturbed topset apron, mudflow gully, mudflow lobe, and prodelta), centering around mudflow distribution initiated by a variety of factors (hurricanes, storms, and fluid pressure). To better understand the spatiotemporal scales of the events as well as the controlling processes, eight cores (5.8–8.0 m long) taken offshore from the South Pass (SP) and the Southwest Pass (SWP) were analyzed for gamma density, grain size, sediment fabric (X-radiography), and geochronology (210Pb/137Cs radionuclides). Previous work has focused on the deposition of individual passes and has been restricted to <3 m core penetration, limiting its geochronologic completeness. Building on other recent studies, within the mudflow gully and lobe cores, the homogeneous stepped profiles of 210Pb activities and the corresponding decreased gamma density indicate the presence of gravity-driven mass failures. 210Pb/137Cs indicates that gully sedimentary sediment accumulation since 1953 is greater than 580 cm (sediment accumulation rate [SAR] of 12.8 cm/y) in the southwest pass site, and a lower SAR of the South Pass gully sites (2.6 cm/y). This study shows that (1) recent dated mudflow deposits are identifiable in both the SWP and SP; (2) SWP mudflows have return periods of 10.7 y, six times more frequent than at the SP (66.7 y); (3) 210Pb inventories display higher levels in the SWP area, with the highest focusing factors in proximal/gully sedimentation, and (4) submarine landslides in both study areas remain important for sediment transport despite the differences in sediment delivery and discharge source proximity.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Factors Influencing the Amplitude of Local Ice Pressure on Vertical Structures Based on Model Tests","authors":"Ying Xu, Dayong Zhang, Kuankuan Wu, Xin Peng, Xunxiang Jia, Guojun Wang","doi":"10.3390/jmse12091634","DOIUrl":"https://doi.org/10.3390/jmse12091634","url":null,"abstract":"Local ice pressure refers to the ice pressure exerted on a very small area of a structure during ice failure. The existence of high-pressure zones may lead to local deformation and damage to ice-resistant structures, posing a serious threat to the overall structural stability. This study simulates the interaction between sea ice and structures through model tests, analyzing the timing of extreme local ice pressures. The results show that at low loading speeds, there is a 50% probability that the extreme local ice pressure occurs at the peak of the global ice force, while at high loading speeds, this probability drops to around 25%. Further investigation into the relationship between the global ice force peak, ice thickness, loading speed, and local area with local ice pressure amplitude reveals that the local ice pressure amplitude decreases with increasing loading speed and increases with ice thickness. Based on the area averaging method for square regions, the relationship between local ice pressure amplitude and local area is studied, showing that ice thickness, local width, and loading speed all influence the pressure–area relationship. Based on the square area averaging method, the relationship between the local ice pressure amplitude and the local area was studied. It was found that a linear relationship exists between the power function coefficient of local ice pressure–area and the thickness-to-width ratio. Compared to brittle failure, the local ice pressure amplitude under ductile failure of the ice sheet is more significantly affected by ice thickness. This study provides a foundation and reference for the analysis of ice-resistant performance and structural design of polar marine engineering structures.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Efficient Autonomous Exploration Framework for Unmanned Surface Vehicles in Unknown Waters","authors":"Baojian Song, Jiahao Zhang, Xinjie Han, Yunsheng Fan, Zhe Sun, Yingjie Wang","doi":"10.3390/jmse12091622","DOIUrl":"https://doi.org/10.3390/jmse12091622","url":null,"abstract":"The detection of unknown waters has been studied and applied in various fields, such as national defense, military operations, engineering surveying and mapping, and scene reconstruction. To improve exploration efficiency in unknown waters, this paper proposes a framework for autonomous exploration using unmanned surface vehicles (USVs). This framework, comprising a multi-stage exploration strategy and a hierarchical navigation strategy, is designed to mitigate the inherent restrictions between the exploration target point and exploration direction in USV operations. These two strategies are optimized for the exploration target point and feasible navigation route to address the problem of the USV’s limited mobility during exploration. Rapidly exploring random tree (RRT) and boundary detection methods are used in the local layer to find the boundary in front of and behind the USV, and the gain of the target point is optimized. The hierarchical navigation method is implemented in the global layer to plan appropriate navigation paths. The proposed method is tested in simulations in several virtual environments and contrasted with the conventional methods currently in use. The findings indicate that our strategy covers more ground more effectively than other methods (our method achieved an exploration efficiency ranging from 4.9 to 5.3 m2/s, whereas traditional methods ranged from 2.3 to 3.9 m2/s, which demonstrates that our approach can improve exploration efficiency by up to 200% compared to traditional methods), spending less time exploring while significantly reducing collision probability.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intelligent Ships and Waterways: Design, Operation and Advanced Technology","authors":"Chenguang Liu, Wengang Mao, Jialun Liu, Xiumin Chu","doi":"10.3390/jmse12091614","DOIUrl":"https://doi.org/10.3390/jmse12091614","url":null,"abstract":"Intelligent ships have been attracting much attention with the intention of downsizing the number of staff, increasing efficiency, saving energy, etc [...]","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geometric Evaluation of the Hydro-Pneumatic Chamber of an Oscillating Water Column Wave Energy Converter Employing an Axisymmetric Computational Model Submitted to a Realistic Sea State Data","authors":"Édis Antunes Pinto Júnior, Sersana Sabedra de Oliveira, Phelype Haron Oleinik, Bianca Neves Machado, Luiz Alberto Oliveira Rocha, Mateus das Neves Gomes, Elizaldo Domingues dos Santos, José Manuel Paixão Conde, Liércio André Isoldi","doi":"10.3390/jmse12091620","DOIUrl":"https://doi.org/10.3390/jmse12091620","url":null,"abstract":"In this research, considering the air methodology, an axisymmetric model was developed, validated, and calibrated for the numerical simulation of an Oscillating Water Column (OWC) converter subjected to a realistic sea state, representative of the Cassino beach, in the south of Brazil. To do so, the Finite Volume Method (FVM) was used, through the Fluent software (Version 18.1), for the airflow inside the hydro-pneumatic chamber and turbine duct of the OWC. Furthermore, the influence of geometric parameters on the available power of the OWC converter was evaluated through Constructal Design combined with Exhaustive Search. For this, a search space with 100 geometric configurations for the hydro-pneumatic chamber was defined by means of the variation in two degrees of freedom: the ratio between the height and diameter of the hydro-pneumatic chamber (H1/L1) and the ratio between the height and diameter of the smallest base of the connection, whose surface of revolution has a trapezoidal shape, between the hydro-pneumatic chamber and the turbine duct (H2/L2). The ratio between the height and diameter of the turbine duct (H3/L3) was kept constant. The results indicated that the highest available power of the converter was achieved by the lowest values of H1/L1 and highest values of H2/L2, with the optimal case being obtained by H1/L1 = 0.1 and H2/L2 = 0.81, achieving a power 839 times greater than the worst case. The values found are impractical in real devices, making it necessary to limit the power of the converters to 500 kW to make this assessment closer to reality; thus, the highest power obtained was 15.5 times greater than that found in the worst case, these values being consistent with other studies developed. As a theoretical recommendation for practical purposes, one can infer that the ratio H1/L1 has a greater influence over the OWC’s available power than the ratio H2/L2.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-Repetitive Time-Shifted Seismic Monitoring Study Based on Ocean Bottom Cable and Towed Streamer Data","authors":"Fengying Chen, Xiangchun Wang, Wei Liu, Yibin Li, Zhendong Liu","doi":"10.3390/jmse12091615","DOIUrl":"https://doi.org/10.3390/jmse12091615","url":null,"abstract":"Time-shifted seismic research plays an important role in monitoring changes in the gas-water interface uplift, the weakening of amplitude attributes, and gas distribution due to mining. When time-shifted seismic research involves non-repeatable data with significant differences between data sets due to variations in seismic data acquisition parameters and seismic geometries, it necessitates consistent processing before time-shifted monitoring comparisons. In this paper, a study of time-shifted seismic monitoring using two non-repetitive data sets based on the ocean bottom cable (OBC) and towed streamer data is presented. First, amplitude, frequency, wavelet, and time difference are processed to achieve consistency for time-shifted comparisons. Secondly, three modes of seismic geometry normalization are compared to optimize the appropriate offset, azimuth, and signal-to-noise ratio (SNR). Finally, after eliminating the fault surface wave, the maximum trough amplitude attribute is extracted for the same position in the two data sets to analyze time-shifted differences under the three modes using the ratio method and difference method. The conclusions show the following: the OBC and towed streamer data can achieve consistency in terms of amplitude, frequency, wavelet, azimuth, SNR, and time difference; the data reconstruction method outperforms other methods in normalizing offset, azimuth, and SNR; and the time-shifted comparison method of the amplitude attribute ratio method proves more effective than the difference method. This study offers a reliable foundation for future time-shifted seismic research with non-repetitive data to monitor changes in subsurface oil and gas. It also provides a methodological basis for carbon capture and storage (CCS) monitoring technology.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WaterSAM: Adapting SAM for Underwater Object Segmentation","authors":"Yang Hong, Xiaowei Zhou, Ruzhuang Hua, Qingxuan Lv, Junyu Dong","doi":"10.3390/jmse12091616","DOIUrl":"https://doi.org/10.3390/jmse12091616","url":null,"abstract":"Object segmentation, a key type of image segmentation, focuses on detecting and delineating individual objects within an image, essential for applications like robotic vision and augmented reality. Despite advancements in deep learning improving object segmentation, underwater object segmentation remains challenging due to unique underwater complexities such as turbulence diffusion, light absorption, noise, low contrast, uneven illumination, and intricate backgrounds. The scarcity of underwater datasets further complicates these challenges. The Segment Anything Model (SAM) has shown potential in addressing these issues, but its adaptation for underwater environments, AquaSAM, requires fine-tuning all parameters, demanding more labeled data and high computational costs. In this paper, we propose WaterSAM, an adapted model for underwater object segmentation. Inspired by Low-Rank Adaptation (LoRA), WaterSAM incorporates trainable rank decomposition matrices into the Transformer’s layers, specifically enhancing the image encoder. This approach significantly reduces the number of trainable parameters to 6.7% of SAM’s parameters, lowering computational costs. We validated WaterSAM on three underwater image datasets: COD10K, SUIM, and UIIS. Results demonstrate that WaterSAM significantly outperforms pre-trained SAM in underwater segmentation tasks, contributing to advancements in marine biology, underwater archaeology, and environmental monitoring.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metachromadora parobscura sp. nov. and Molgolaimus longicaudatus sp. nov. (Nematoda, Desmodoridae) fromMangrove Wetlands of China","authors":"Jing Sun, Yong Huang","doi":"10.3390/jmse12091621","DOIUrl":"https://doi.org/10.3390/jmse12091621","url":null,"abstract":"Two new species of free-living marine nematodes, Metachromadora parobscura sp. nov. and Molgolaimus longicaudatus sp. nov., from mangrove wetlands of Beihai, Guangxi province in China, are described. Metachromadora parobscura sp. nov. is characterized by eight longitudinal rows of somatic setae arranged from the posterior part of the body, loop-shaped amphidial foveae with an open top and double contours, pharynx with bipartite cuticularized internal cavity, spicules with well-developed capitulum, gubernaculum canoe-shaped, without apophysis, 6–8 precloacal tubular supplements, and a short, conical tail with two ventral protuberances. It could be easily distinguished from the known species by spicule length and numbers of precloacal supplements. Molgolaimus longicaudatus sp. nov. is characterized by short cephalic setae, relatively small amphidial fovea, slender spicules ventrally bent with pronounced hooked capitulum and tapered distal end, two poriform precloacal supplements, and a relatively long conico-cylindrical tail. It differs from other species by the shape of spicules and long tail. Nearly full-length SSU sequences (1542–1592 bp) of the two species were provided, and phylogenetic trees based on maximum likelihood analyses supported the taxonomic position of the two new species. The combined use of traditional morphology-based taxonomy and molecular approaches has been proven to be a good choice for identification of free-living nematodes.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification and Validation Analysis on Marine Applications","authors":"Simone Mancini, Momchil Terziev","doi":"10.3390/jmse12091618","DOIUrl":"https://doi.org/10.3390/jmse12091618","url":null,"abstract":"Both users and developers of computational simulations are facing a crucial dilemma—how can confidence in modelling and simulation be properly evaluated [...]","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Responses of Different Morphological Cells of Phaeocystis globosa to UV-B Radiation","authors":"Wei Wei, Jie Li, Caibi Lan, Junxiang Lai","doi":"10.3390/jmse12091619","DOIUrl":"https://doi.org/10.3390/jmse12091619","url":null,"abstract":"Phaeocystis globosa is an important member of the plankton community and was considered to be a typical bloom-forming algae. Its life cycle is variable, comprising both solitary and colony cells. The growth process of P. globosa is vulnerable to UV-B radiation. However, the influence of UV-B on photosynthetic activity and the resulting programmed cell death (PCD) process is not entirely understood. Our findings demonstrated that Fv/Fm, rETRmax, Y(II) and α of solitary and colony cells were significantly decreased after UV-B treatment (p < 0.05). The colony cells showed a lower damage rate and higher repair rate than solitary cells (p < 0.05), suggesting that colony cells have better UV-B radiation resistance. After UV-B radiation, we found the characteristic markers of PCD-phosphatidylserine (PS) externalization and DNA fragmentation were discovered in the two cell morphologies, with increased caspase-3-like activity, proving the onset of PCD. In addition, the reactive oxygen species (ROS) content and antioxidant enzyme activities were examined. The results showed that, the ROS content went up, the solitary cells were significantly greater than colony cells under UV-B radiation (p < 0.001). In addition, the superoxide dismutase (SOD) and catalase (CAT) activities increased, and solitary cells always had significantly higher activity than colony cells (p < 0.05), but the changing trend in ROS content did not match the changes in CAT and SOD activities. This may have been due to the necrosis of solitary cells. The findings show that, besides PCD, solitary cells also developed necrosis under UV-B radiation. This study provides evidence that different morphological cells of marine microalgae present different reactions to UV-B radiation. It helps to further improve the knowledge of the environmental adaptation mechanism of P. globosa.","PeriodicalId":16168,"journal":{"name":"Journal of Marine Science and Engineering","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}