Search results for "offshore"

Contaminated sediments from dredging activities as modern turbidites: geochemical signatures in box-core sediments from the Augusta area, Ionian Sea,…

2009

The Augusta area (SE Sicily) is one of the most industrialized and contaminated coastal environments in the Mediterranean region, having a relatively high influx of unregulated industrial effluents. Valuable sets of geochemical data (major elements and trace metals), obtained from box-core sediments collected along a transect from the Sicilian coastal zone seawards of Augusta and dated via 210Pb and 137Cs, indicated increased metal contamination (notably Hg) since ca 1940-1950, related to the industrial development of the area. Metal enrichment is considerable in the coastal sediments, being significantly in excess (for Hg and Pb) of background values estimated for the Strait of Sicily. Mor…

Energy and economic assessment of a small domestic wind turbine in Palermo

2016

The cost effectiveness of micro-wind technology is closely linked to the annual energy production plants, which strongly depends on the wind characteristics and on the morphological properties of the installation site. The power curve of a wind turbine, supplied by manufacturers, characterizes the theoretical energy performance that it should have at a particular site. The behavior of a wind turbine in the field is affected by the speed but also by wind direction variations. At each change of direction and speed, the turbine will try to adapt to new conditions and the phase transition negatively influences the energy production. In order to experimentally confirm what above mentioned, the a…

Late Quaternary sedimentary evolution of the Castellammare Gulf (North-Western Sicily offshore)

2005

High-resolution seismic stratigraphy has been applied to the interpretation of the stratigraphic architecture of Late Pleistocene and Holocene successions on the continental shelf and upper slope of the Gulf of Castellammare, North-Western Sicily. The Late Quaternary type 1 depositional sequence is bounded by a regional unconformity and it is made up of four systems tracts, developed under fourth order relative sea level fluctuations, after the previous highstand of isotope Stage 5e. Systems tract are located in different parts of the basin, two being confined to the outer shelf and the upper slope, the other developed along the inner shelf. Facies associations, geomorphological elements, a…

Model based design of electro-hydraulic motion control systems for offshore pipe handling equipment

2014

Doktorgradsavhandling i mekatronikk, Universitetet i Agder, 2014 Despite the fact that hydraulics, in general, is considered a mature technology, design of hydraulic systems still offers a number of challenges for both component suppliers and manufacturers of hydraulically actuated machines such as offshore pipe handling equipment. This type of equipment is characterized by high price, high level of system complexity and low production numbers. It requires a great level of skill and experience to develop the equipment and the focus on production and development costs is constantly increasing. Therefore design engineers continuously have to improve their procedures for decision making regard…

Enabling Energy Savings in Offshore Mechatronic Systems by using Self-Contained Cylinders

2019

This paper proposes a novel actuation system for an offshore drilling application. It consists of three self-contained electro-hydraulic cylinders that can share and store regenerated energy. The energy saving potential of the proposed solution is analyzed through a multibody system simulation. The self-contained system demonstrates superior energy efficiency compared to the benchmark system representing the state-of-the-art approach used today (i.e., valve-controlled cylinders by means of pressure-compensated directional control valves and counter-balance valves, supplied by a centralized hydraulic power unit). Due to the power on demand capability, the cancellation of the throttling losse…

Toward farm-level health management of wind turbine systems: status and scope for improvements

2018

An outline of health management for OWFs has been detailed in this chapter with description of various important elements. The need for such farm level management is explained and benefits are discussed. Key gaps to be filled in order to realize such a system are identified. The proposed health management system is mainly based on the existing knowledge of fleet-level management in the aerospace sector. Health management is much broader than CM; there are a number of aspects beyond the prognostics capabilities that are to be designed in order to arrive at a comprehensive maintenance management scheme. A comprehensive maintenance program that is sensitive to the health of the assets and adap…

An Approach to the conversion of the power generated by an offshore wind power farm connected into seawave power generator

2011

Optimisation through offshore – between reality and legality

2021

The study highlights the complete image of the characteristics regarding offshore areas, by taking into account the perspective to deploy new measures of fiscal transparency. The importance of such areas stems from the fact that world economies lose important sums of money, every year by default of taxes. This happens as a consequence of corporative international abuse of fiscal evasion and the relocation of the profit made by big companies. The sums resulted from erosion of national taxation bases, from fiscal evasion and fraud and other infringements connected with fiscal evasion (are often being transferred to offshore companies so that their illegal characteristics gets lost and after t…

HIGH-RESOLUTION SEISMIC SURVEY IN THE WESTERN CALABRIA AND EASTERN SICILY OFFSHORE: IMPLICATIONS WITH VERTICAL TECTONICS

2016

High-resolution seismic data acquired along the continental shelf/upper slope offshore of Capo Vaticano (western Calabria), Milazzo Promontory and Mt. Etna (eastern Sicily) allow to provide new insights on vertical mobility related to active tectonics. A number of depositional sequences bounded by unconformities or correlative para-conformities were recognized on Sparker profiles in the first 200-300 m below the sea-floor. The most recent sequence overlays a widespread erosional surface that ostensibly formed during the sea level stillstand of the Last Glacial Maximum (LGM), whereas a stack of depositional sequences, which are interpreted as representing the falling and low-stand systems tr…

Practice for determining friction in hydraulic winch systems

2020

This paper presents a method for estimating friction in hydraulic active heave compensated (AHC) offshore winches. The method is a two-step approach where the first step is to model the friction loss in the hydraulic motors based on data from the sub-supplier. The second step requires real-life testing, where the remaining friction losses in the winch system is identified and modeled. In this context, a practice is characterized by obtaining a friction loss estimation with the highest possible accuracy over the widest possible range of operating conditions with a limited amount of experimental work. The method benefits from the use of parametric models, sub-supplier data, and real-life meas…