Search results for "Offshore"

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…

Relative Vessel Motion Tracking using Sensor Fusion, Aruco Markers, and MRU Sensors

2017

This paper presents a novel approach for estimating the relative motion between two moving offshore vessels. The method is based on a sensor fusion algorithm including a vision system and two motion reference units (MRUs). The vision system makes use of the open-source computer vision library OpenCV and a cube with Aruco markers placed onto each of the cube sides. The Extended Quaternion Kalman Filter (EQKF) is used for bad pose rejection for the vision system. The presented sensor fusion algorithm is based on the Indirect Feedforward Kalman Filter for error estimation. The system is self-calibrating in the sense that the Aruco cube can be placed in an arbitrary location on the secondary ve…

Mapping the potential for offshore aquaculture of salmonids in the Yellow Sea

2022

AbstractMariculture has been one of the fastest-growing global food production sectors over the past three decades. With the congestion of space and deterioration of the environment in coastal regions, offshore aquaculture has gained increasing attention. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two important aquaculture species and contribute to 6.1% of world aquaculture production of finfish. In the present study, we established species distribution models (SDMs) to identify the potential areas for offshore aquaculture of these two cold-water fish species considering the mesoscale spatio-temporal thermal heterogeneity of the Yellow Sea. The values of the a…

Analysis and assessment of trace element contamination in offshore sediments of the Augusta Bay (SE Sicily): A multivariate statistical approach base…

2014

Abstract An application of multivariate statistical methods is provided to identify anthropogenic contaminants and lithogenic elements in offshore sediments collected near the heavily industrialized Augusta Bay, Sicily. An exploratory statistical technique, based on canonical correlation analysis (CCA) and mixture density estimation approach, is used for distinguishing between natural and anthropogenic contributions of trace elements in the investigated sediments. Following the intensive industrialization of Augusta area, marine sediments reveal the severe impact of local anthropogenic activities for many elements (e.g. As, Cd, Hg, Pb, and Sb), which are considered very dangerous for the en…

Evidences of mud volcanoes in the Palermo and Termini Gulf (N Sicily offshore)

2009

The occurrence of mud volcanoes and mud domes is, for the first time, documented in the continental shelf and upper slope of the Palermo and Termini Gulf (north Sicily offshore region). The study area belongs to the northern Sicily continental margin (southern Tyrrhenian Sea). Along this margin, morphology of the high-gradient continental slope is irregular due to the presence of structural highs, slope failures and canyons, and is interrupted by a flat area at a depth of 1,500 m. Mud volcano activity generally formed in areas characterised by high sedimentation rates and/or as consequences of regional tectonics (often compressional), overpressure in the sediments and gas generated at diffe…

Carte marine e rischi geologici

2008

The investigations carried out by the "Gruppo di Geologia Marina" of the Palermo University in the framework of the CARG project, have been focused on the marine sectors between the Egadi Islands offshore and the Cefalù Basin (NW Sicilian offshore). The research activities have yielded new results on the following fields: (i) sedimentation and coastal dynamics, (ii) sea bottom cartography and mapping of submerged structures, (iii) morpho-bathymetry and geological risk assessment

PRIN Project 2010-11 “Active and recent geodynamics of Calabrian Arc and accretionary complex in the Ionian Sea”: new constraints from geological, ge…

2014

This contribution illustrates the preliminary results of our Research Unit in the PRIN Project 2010-11, which focuses on active and recent geodynamics of Calabrian Arc. The integration of the new geological, geodetic and seismological data supports the inferred recent plate boundary reorganization in the central-southern Mediterranean, where the regional GNNS velocity fields point to a deceleration or cessation of Calabrian Arc migration, and to extension along the axis of the Calabrian Arc, accommodated by normal faulting (e.g. Capo Vaticano and Messina Straits (Aloisi et al., 2012; Pepe et al., 2014; Spampinato et al., 2014). The study of the lateral borders of the Arc revealed that obliq…

From land to sea: multi-scale and multi-resolution analysis of active deformation and seismogenic sources around the coasts of Southern Italy

2016

During the last decade, we have blended our individual skills to form a research group devoted to investigating active crustal deformation in areas adjacent to the coast of Southern Italy, with the aim to bridge the gap between the onshore and offshore realms. Our research is based on a multi-scale and multi-resolution approach that includes high-resolution seismics, coastal morpho-tectonics and structural geology, complemented by seismicity, Global Positioning System and InSAR. Need and opportunities of such an endeavor arise from the basic observation that, although most population centers lie close to the coastal areas, very little is known about active structures at the sea. However, hi…

Waveforms clustering of small magnitude earthquakes recorded in the Northern Sicilian offshore: evidence of multiplets

2011

Wave and Wind Energy Systems Integration in Vietnam: Analysis of Energy Potential and Economic Feasibility

2020

Vietnam energy demand is currently growing at a very high annual rate, with the government being very interested in investments in renewable energies. Since the region with the highest solar and wind potential is far away from the big load centers, an investigation of offshore energy resources is here proposed. In this study, a review of previous energy potential assessments is provided. Moreover, the minimum feed-in-tariff to make the investments profitable is evaluated, showing that the current tariff for offshore wind plants is largely unattractive.