Search results for "Submarine"

Small changes, big impacts: Geographic expansion in small-scale fisheries

2020

Abstract Small-scale fisheries are an important, yet neglected, millenarian activity that has been undergoing significant changes that threaten its future. Understanding how this activity is spatially distributed and the factors that drive its use of the marine space over time can shed some light on how fishing efforts and their impacts have moved over different parts of coastal marine ecosystems. This study investigated changes to the spatial distribution of small-scale fisheries along the Brazilian equatorial region between 1994 and 2014 and the factors, from ecological to socioeconomic, that influenced this shift. Bayesian hierarchical spatial models were used together with environmental…

Modeling of Offshore Crane and Marine Craft in Wave Motion

2020

Safe handling of heavy payloads in an offshore environment requires careful planning and depends on the interaction between a crane and a vessel. This paper investigates the coupled dynamics between a multipurpose crane with payload, and an offshore carrying vessel. A classical multi-body model is derived using holonomic constraints and Newton-Euler kinetics. The resulting index-3 system of differential-algebraic equation (DAE) is transformed into an index-1 system and solved using commonly used numerical ode solvers. Numerical simulations are carried out to show that the proposed models behave in a physically realistic manner. © 2020 IEEE. Personal use of this material is permitted. Permis…

A possible evolutionary model of “aligned pockmarks”

2014

Autonomous Mooring towards Autonomous Maritime Navigation and Offshore Operations

2020

Bollard is a vital component of mooring system. It is the anchor point for mooring ropes to be fixed in order to secure the vessel or ship. An algorithm that translates the segmented mask of bollard output from masked R-CNN along with bounding box and associated class probability to its corresponding edge coordinate and finally to the single reference point for efficient detection and classification of bollard towards autonomous mooring is presented. At first stage, Mask R-CNN framework is trained with custom built bollard. The model obtained from the training is inferred with real data resulting in instance segment of bollard. The segmented mask obtained contains relatively large amount of…

Polarization and high resolution parametric spectral analysis applied to the seismic signals recorded on the Marsili submarine volcano

2008

Monitoring Mediterranean marine pollution using remote sensing and hydrodynamic modelling

2011

Human activities contaminate both coastal areas and open seas, even though impacts are different in terms of pollutants, ecosystems and recovery time. In particular, Mediterranean offshore pollution is mainly related to maritime transport of oil, accounting for 25% of the global maritime traffic and, during the last 25 years, for nearly 7% of the world oil accidents, thus causing serious biological impacts on both open sea and coastal zone habitats. This paper provides a general review of maritime pollution monitoring using integrated approaches of remote sensing and hydrodynamic modeling; focusing on the main results of the MAPRES (Marine pollution monitoring and detection by aerial survei…

Waterfront and Transformation in Contexts of Conflict

2016

This chapter defines in what way the seaside and the waterfront can be place of conflicts among infrastructures, production, unplanned urbanisation, bathing tourism and many other activities. The last section of the chapter describes synthetically the study case of Saint-Nazare Submarine base and the terms of regeneration of a typically place of conflict, like a military area connected with the waterfront. The transformations underway in the waterfront areas present a variety of complex settlement dynamics that are ascribable to the infrastructural and productive nature of many activities, such as unplanned urbanisation, the pressures of bathing tourism and mass tourism, and the system of s…

Assessment of the Present and Future Offshore Wind Power Potential: A Case Study in a Target Territory of the Baltic Sea Near the Latvian Coast

2013

Offshore wind energy development promises to be a significant domestic renewable energy source in Latvia. The reliable prediction of present and future wind resources at offshore sites is crucial for planning and selecting the location for wind farms. The overall goal of this paper is the assessment of offshore wind power potential in a target territory of the Baltic Sea near the Latvian coast as well as the identification of a trend in the future wind energy potential for the study territory. The regional climate model CLM and High Resolution Limited Area Model (Hirlam) simulations were used to obtain the wind climatology data for the study area. The results indicated that offshore wind en…

Submarine groundwater discharge investigations in Sicilian and Brazilian coastal waters using an underwater gamma-ray spectrometer

2006

Abstract Submarine groundwater discharge (SGD) in coastal zones was monitored using in situ underwater gamma-ray spectrometry of radon decay products ( 214 Bi). Several sites were visited during the IAEA'2002 expedition to south-eastern Sicily, where SGD variations were observed in the Donnalucata boat basin. The continuous monitoring carried out for 3 days at the site closest to the coast revealed an anticorrelation dependence of 222 Rn concentration with tide and salinity. The 222 Rn activity concentrations in seawater varied from 2.3 kBq m −3 (during high tides) to 4.8 kBq m −3 (during low tides). In situ gamma-ray spectrometric measurements were also carried out during the IAEA–UNESCO'2…

Offshore wind turbine operations and maintenance: A state-of-the-art review

2021

Abstract Operations and maintenance of offshore wind turbines (OWTs) play an important role in the development of offshore wind farms. Compared with operations, maintenance is a critical element in the levelized cost of energy, given the practical constraints imposed by offshore operations and the relatively high costs. The effects of maintenance on the life cycle of an offshore wind farm are highly complex and uncertain. The selection of maintenance strategies influences the overall efficiency, profit margin, safety, and sustainability of offshore wind farms. For an offshore wind project, after a maintenance strategy is selected, schedule planning will be considered, which is an optimizati…