Search results for "Shore"

Tunable Structure and Properties of Segmented Thermoplastic Polyurethanes as a Function of Flexible Segment

2019

Segmented thermoplastic polyurethanes (PUs) were synthetized using macrodiols with different functional groups (carbonate, ester, and /or ether) as a segment with a molar mass of 1000 and 2000 g/mol, and 4,4&rsquo

Beaches in Valencian Coast

2018

The main factors that determined the Valencian beaches characteristics are the configuration of relief structures; fluvial sediment supply; low tidal range; the predominance of low energy waves; scarcity of big storms; longshore littoral drift; and human action. There is a significant prevalence of sandy beaches. Nevertheless, both at the northern part of the Gulf of Valencia and in the structural segment, between the Cape Sant Antoni and Alicante city, pebble and gravel beaches are predominant. Most of the Valencian beaches have experienced significant morphological changes during the last decades due to the human interventions -voluntary or involuntary- in the coastal system. The implemen…

Dynamics of sediments along with their core properties in the Monastir-Bekalta coastline (Tunisia, Central Mediterranean)

2017

International audience; The authors report on two campaigns of high-resolution samplings along the shores of Monastir Bay in Tunisia: the first being a study of sediment dynamics, grain size and mineral composition in surface sediment, and the second, eight months later, using four sediment cores to study grain-size distribution in bottom sediments. Particle size analysis of superficial sediment shows that the sand in shallow depths is characterized by S-shaped curves, indicating a certain degree of agitation, possible transport by rip currents near the bottom and hyperbolic curves illustrating heterogeneity of sand stock. The sediments settle in a relatively calm environment. Along the bay…

Extended Environmental Contour Methods for Long-Term Extreme Response Analysis of Offshore Wind Turbines1

2020

Abstract Environmental contour method is an efficient method for predicting the long-term extreme response of offshore structures. The traditional environmental contour is obtained using the joint distribution of mean wind speed, significant wave height, and spectral peak period. To improve the accuracy of traditional environmental contour method, a modified method was proposed considering the non-monotonic aerodynamic behavior of offshore wind turbines. Still, the modified method assumes constant wind turbulence intensity. In this paper, we extend the existing environmental contour methods by considering the wind turbulence intensity as a stochastic variable. The 50-year extreme responses …

IT-sikkerhetspolicy for Integrerte operasjoner

2007

Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad Ved å benytte IKT i alle ledd i oljeindustrien, vil man oppnå hurtigere og bedre beslutninger, og med hjelp av sanntidsdata kan man integrere arbeidsprosesser på tvers av fag og mellom organisasjoner. Denne utviklingen blir i oljenæringen kalt Integrerte operasjoner (IO). Ved hjelp av IO kan operasjoner styres uavhengig av avstand og geografisk lokasjon. Det er satt inn store ressurser på dette feltet, og allerede i dag ser man vellykkede implementeringer av Integrerte operasjoner. Med Internett som en del av bærenettverket for data produsert i oljenæringen, vil trafikken i utgangspunktet være svært …

Ricostruzione paleoclimatica degli ultimi 16.000 anni nella carota MSK12-C1 (Tirreno Meridionale)

2013

Semiactive vibration control of offshore wind turbine towers with tuned liquid column dampers using H<inf>∞</inf> output feedb…

2010

This short paper addresses the problem of vibration in wind turbine towers. These structures are subject to winds and waves causing undesirable vibrations that affect the structure integrity and system performance. In order to mitigate the vibrations of the tower, a controllable tuned liquid column damper is placed on its top. We propose the use of H ∞ control techniques to formulate a control law. Furthermore, the controller uses output feedback to avoid the dependence on the knowledge of the states of the system. Simulation results illustrate the design procedure proposed in this paper.

Numerical and analytical analysis of a monopile-supported offshore wind turbine under ship impacts

2021

Abstract Offshore wind turbines in the vicinity of ship traffic are exposed to increased risks of ship collisions. To better understand the impact mechanism, this paper evaluates the dynamic responses of a monopile-supported wind turbine under ship impacts, using both numerical and analytical methods. The nonlinear finite element method is applied during the numerical simulations, and the wind load effects, soil conditions, and rigid and deformable ship bows are considered. The analytical approach, originally developed based on the energy method, is extended here to address the damping effects of monopile-supported wind turbines. In the case study, the impacts are studied between a 4600-ton…

Offshore wind metadata management

2014

Offshore wind energy is gaining more and more attention from industry and research community due to its high potential in producing green energy and lowering price on electricity consumption. However, offshore wind is facing many challenges, and hence it is still expensive to install in large scale. It therefore needs to be considered from different aspects of technologies in order to overcome these challenges. One of the problems of the offshore wind is that information comes from different sources with diversity in types and format. Besides, there are existing wind databases that should be utilised in order to enrich the knowledge base of the wind domain. This paper describes an approach …

A comparative study on the dynamic response of three semisubmersible floating offshore wind turbines

2019

Abstract Currently, there is a great interest to globally develop offshore wind energy due to the greenhouse effect and energy crisis. Great efforts have been devoted to develop reliable floating offshore wind energy technology to exploit the wind energy resources in deep seas. This paper presents a comparative study of the dynamic response of three different semisubmersible floating wind turbine structures. All the three platforms support the same 5MW wind turbine. The platforms examined are: a V-shaped Semi, an OC4-DeepCwind Semi and a Braceless Semi at 200 m water depth. A dynamic analysis is carried out in order to calculate and compare the performance of these platforms. The comparison…