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\"This comprehensive practitioner guide presents CP theory to industry recognised codes for basic and advanced applications to metals, with an outline of subsea coating systems. It covers retrofitting and for internal applications, along with computational modelling, and the management of offshore CP systems\"-- Provided by publisher.

Seasonal movements between the summer and winter areas are a widespread phenomenon in bats So far, most information on the migration ecology of bats has been obtained by studies in terrestrial habitats, whereas scientific knowledge on migration over sea is scarce. We performed continuous ultrasonic acoustic monitoring at 13 locations in the southern North Sea during four consecutive years (2017–2020) and analysed the spatiotemporal occurrence of Nathusius’ pipistrelle Pipistrellus nathusii during autumn migration in relation to weather parameters and lunar phase. Our analysis showed that the main autumn migration of Nathusius’ pipistrelle at the southern North Sea occurs from mid-August until late October and most bats within the study area occur off the Noord Holland coast. North Sea crossings frequently last longer than one night; the day is spent roosting at an offshore structure. The strongest migration occurs during nights with tailwinds from the east-northeast, but bats are also recorded offshore with low to moderate headwinds or crosswinds. Bat presence decreased between the full moon and the last quarter and increased just before the new moon. Finally, our observations show that the occurrence of bats at sea was reduced in 2020 in comparison to the previous years. The results of this study show clear spatiotemporal patterns of migratory bat occurrence at the southern North Sea. The spatial distribution can be used in spatial planning of future offshore wind farms, whereas the temporal occurrence and environmental factors that shape offshore migration can be used to develop mitigation measures to reduce the number of bat fatalities.

Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of offshore platforms on marine life. Information on this is limited for offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five offshore gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001): from a low richness in shallow waters it increases with depth until 15-20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001), community age (p≤0.001) and the interaction between distance from shore and community age (p≤0.001) showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages.

A comprehensive overview of managing and assessing safety and functionality of ageing offshore structures and pipelines A significant proportion, estimated at over 50%, of the worldwide infrastructure of offshore structures and pipelines is in a life extension phase and is vulnerable to ageing processes. This book captures the central elements of the management of ageing offshore structures and pipelines in the life extension phase. The book gives an overview of: the relevant ageing processes and hazards; how ageing processes are managed through the life cycle, including an overview of structural integrity management; how an engineer should go about assessing a structure that is to be operated beyond its original design life, and how ageing can be mitigated for safe and effective continued operation. Key Features: * Provides an understanding of ageing processes and how these can be mitigated. * Applies engineering methods to ensure that existing structures can be operated longer rather than decommissioned unduly prematurely. * Helps engineers performing these tasks in both evaluating the existing structures and maintaining ageing structures in a safe manner. The book gives an updated summary of current practice and research on the topic of the management of ageing structures and pipelines in the life extension phase but also meets the needs of structural engineering students and practicing offshore and structural engineers in oil & gas and engineering companies. In addition, it should be of value to regulators of the offshore industry.

A rapid development of marine infrastructures can be observed along the global coasts. Offshore wind farms, oil and gas platforms, artificial islands, aquaculture, and more, are being constructed without a proper quantification of these human activities. Therefore, effective monitoring is required to maintain transparency towards environmental standards, marine resource management, inventorying objects, and global security. This study reviews remote sensing-based approaches to offshore infrastructure detection over the past 12 years. We analyzed 89 studies from over 30 scientific journals, highlighting spatial and temporal trends, methodological approaches, and regional and thematic research foci. Our results show a significant increase in research interest, especially since 2019. Asia, and especially China, is the predominant focus region in terms of first authorship, funding, and areas of investigation. Aquaculture is the most studied infrastructure, followed by platforms, offshore wind farms, and artificial islands. Gaofen, Sentinel, and Landsat are the most used satellite sensors for detection. The apparent shift towards automated detection methods, especially Deep Learning algorithms, reflects advances in computer vision. This study highlights the key role of earth observation in the field of off-shore infrastructure detection, which can contribute towards outlining effective monitoring practices for marine activities, as well as highlighting important knowledge gaps.

Photovoltaic (PV) power generation is a form of clean, renewable, and distributed energy that has become a hot topic in the global energy field. Compared to terrestrial solar PV systems, floating photovoltaic (FPV) systems have gained great interest due to their advantages in conserving land resources, optimizing light utilization, and slowing water evaporation. This paper provides a comprehensive overview of recent advancements in the research and application of FPV systems. First, the main components of FPV systems and their advantages as well as disadvantages are analyzed in detail. Furthermore, the research and practical applications of offshore FPV systems, including rigid floating structures and flexible floating structures, are discussed. Finally, the challenges of offshore FPV systems are analyzed in terms of their stability and economic performance. By summarizing current research on FPV systems, this overview aims to serve as a valuable resource for the development of offshore FPV systems.

The unwanted vibrations of offshore structures induced by wave or earthquake loads can lead to the reduction of the service life and fatigue failure of the offshore platforms. This paper introduces tuned inerter damper (TID) to a jacket offshore platform as passive control device for mitigating the excessive vibrations of platform structure induced by wave and earthquake loads. An analytical design method is proposed for jacket platforms and the influence of installation location on the modal response is investigated. The proposed design method can determine the optimal installation position and obtain the optimal design parameters by transform the original multi-degree of freedom (MDOF) system to a single DOF (SDOF) modal system. Two sets of closed-form solutions of which corresponding to wave and earthquake excitations are derived based on the H 2 optimization criterion. Further, a practical 90 (m) high and 80 (m) deep in-water jacket offshore platform is used in numerical simulation and the wave forces are modeled using Morison’s equation. The case study finds that the optimal installation location of TID is deck level for both wave and earthquake loads. The proposed design method is validated by the numerical example and the results demonstrate that TID system can effectively mitigate the maximum, minimum, and RMS responses of jacket platforms. Besides, the TID is more effective when the jacket platform is under the action of waves and the tuning of TID according to earthquake load is more reliable when the jacket platform subjected to both wave and seismic loads.

Two years of continuous sonic anemometer measurements conducted in 2007 and 2008 at the FINO1 platform are used to investigate the characteristics of the single- and two-point velocity spectra in relation to the atmospheric stability in the marine atmospheric boundary layer. The goals are to reveal the limits of current turbulence models for the estimation of wind loads on offshore structures, and to propose a refined description of turbulence at altitudes where Monin–Obukhov similarity theory may be limited. Using local similarity theory, a composite spectrum model, combining a pointed and a blunt model, is proposed to describe the turbulence spectrum for unstable, neutral and stable conditions. Such a model captures the \\[-1\\] power law followed by the velocity spectra at an intermediate frequency range in the marine atmospheric boundary layer. For the Monin–Obukhov similarity parameter \\[\\zeta < 0.3\\], the Davenport coherence model captures the vertical coherence of the horizontal velocity components well. A two-parameter exponential decay function is found more appropriate for modelling the coherence of the vertical velocity component. Under increasingly stable conditions, the size of the eddies in the vertical coordinate reduces, such that smaller separation distances than that covered in the present dataset may be required to study the coherence with sufficient accuracy.

This study was conducted during October 2021 (autumn) and April 2022 (spring) to explore the phytoplankton community structure, their distribution characteristics, and the influence of environmental factors in the coastal waters of the Southern Beibu Gulf. The 15 sampling sites were grouped based on the difference in offshore distance to analyze the temporal and spatial differences in community structure and environmental driving in the investigated sea area of the coastal waters of the Southern Beibu Gulf. Permutational multivariate analysis of variance was conducted on the sample data in time and space, revealing that there is no significant difference in space ( p  > 0.05), but there is significant difference in time ( p  < 0.05). Notably, water pressure, pH, chemical oxygen demand, nitrite, and labile phosphate were higher in autumn, while total ammonia nitrogen, dissolved oxygen, and suspended solids were significantly higher in spring. Additionally, the study identified 87 phytoplankton species belonging to 6 phyla, dominating by Bacillariophyta, followed by Dinophyta and Cyanophyta. The phytoplankton density, Shannon Weiner’s diversity index ( H' ), Pielou’s evenness index (J), and Margalef’s richness index (D) ranged from 84.88 to 4675.33 cells L −1 , 0.56 to 2.58, 0.26 to 0.89, and 1.21 to 3.64, respectively. Permutational multivariate analysis of variance showed non-significant spatial differences in phytoplankton composition ( p  > 0.05) but seasonal differences ( p  < 0.05). Furthermore, canonical correspondence analysis (CCA) identified pH, dissolved oxygen, suspended solids, chemical oxygen demand, nitrite, and labile phosphate as key environmental factors influencing the phytoplankton community structure ( p  < 0.05). In this study, the dynamic changes of phytoplankton community structure and environmental factors in the southern coastal waters of Beibu Gulf were analyzed in detail from two aspects of time and space. The key environmental factors to protect the ecological environment in the southern coastal area of Beibu Gulf were found out. It provides a reference method and theoretical basis for the management and protection of Beibu Gulf and other tropical marine environment.

The current work addresses a mass/cost-optimization procedure for galvanic anode cathodic protection systems based on both cathodic protection (CP) standards and numerical simulation. An approach is developed for optimizing the number and dimensions of the galvanic anodes, distributing the optimized anodes on the support structure, and finally evaluating the protective potential on the structure during the lifetime by using finite element (FE) software. An algorithm based on sequential quadratic programming is used for optimizing the number and dimensions of the anodes. Both simplified and detailed models are suggested for calculating the protective potential on the structure. The simplified model is selected based on its advantages in terms of calculation time and compatibility with DNV standard data. A time-dependent FE model is used to take into account the electrical isolation degradation of the structure coating as well as the mass reduction of the anodes during the CP lifetime. The performance of the proposed optimization process is examined on a mono bucket inspired (with some simplifications) by the Dogger Bank metrological mast in England. The optimized designs for different coating and anode types are compared and the best designs in terms of both cost and protective potential during the lifetime are suggested. The achieved results show that the proposed optimization procedure can reduce the cost of the CP system around 70% compared to the original non-optimized CP design of the Dogger Bank metrological mast. Furthermore, evaluating the time-evolution performance of the CP systems can reduce their lifetime uncertainty.