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Offshore Structures and Hydrodynamic Modeling

Résumé : Offshore structuresOffshore structures (Fig. 9.1) with their facilities are used to drill wells, to extract and process oil and natural gas, or to temporarily store product until it can be brought to
Domaine de référence : EMR
Auteur Jia Junbo
Année de parution : 2017.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Design aspects for monopile foundations

Résumé : This paper describes the outcome of a recently-completed research project – known as PISA – on the development of a new process for the design of monopile foundations for offshore wind turbine support structures. The PISA research was concerned with the use of field testing and three-dimensional (3D) finite element analysis to develop and calibrate a new one-dimensional (1D) design model. The resulting 1D design model is based on the same basic assumptions and principles that underlie the current p-y method, but the method is extended to include additional components of soil reaction acting on the pile, and enhanced to provide an improved representation of the soil-pile interaction behaviour. Mathematical functions – termed ‘soil reaction curves’ – are employed to represent the individual soil reaction components in the 1D design model. Values of the parameters needed to specify the soil reaction curves for a particular design scenario are determined using a set of 3D finite element calibration analyses. The PISA research was focused on two particular soil types (overconsolidated clay till and dense sand) that commonly occur in north European coastal waters. The current paper provides an overview of the field testing and 3D modelling aspects of the project, and then focuses on the development, calibration and application of the PISA design approach for monopiles in dense sand.
Domaine de référence : EMR
Auteur Burd Harvey, Byrne Byron, McAdam RA, Houlsby Guy, Martin Chris, Beuckelaers William, Zdravkovic L, Taborda DMG, Potts David, Jardine Richard, Gavin Ken, Doherty Paul, Igoe David, Skov Gretlund Jesper, Pacheco Andrade Miguel, Muir Wood Alastair
Année de parution : 2017.
Type de document : Livre.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

A Review of Methods and Models for Environmental Monitoring of Marine Renewable Energy

Résumé : A continued expansion of the marine renewable energy sector will result in an increased demand in monitoring the natural marine environment. This may be due to a basic scientific interest but is foremost linked to the requirement of pre-and post-construction studies in relation to environmental impact assessments and consenting processes for marine renewable energy projects. With focus on wave and tidal power, but without attempting to provide a comprehensive list, we review methods, technologies and other scientific tools used for monitoring and predicting possible impacts from marine energy installations, on both population and behavioural levels. This includes traditional methods such as fishing gear, like nets and cages, modern technologies such as platforms with multi parameter equipment and the use of deterministic models. This paper is intended to serve as an overview for technology developers as well as authorities, regulators and decision makers with interests in general techniques, and naturally for scientists and consultants commonly being executors of studies and monitoring programs. By giving relevant and up to date references this paper may also be useful for finding more detailed information on study methods and variants. Finally, we give recommendations on where development of technologies is needed in order to face future requirements.
Domaine de référence : EMR
Auteur Bender Anke, Francisco Francisco, Sundberg Jan
Année de parution : 2017.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Life Cycle Assessment of a multi-use offshore platform : Combining wind and wave energy production

Résumé : Due to increasing demand in the use of ocean space for energy and food production, multi-purpose use of marine areas is under concern. Here, a novel semi-submersible floating platform, which unites wave and wind energy converters, is investigated in terms of environmental sustainability. LCA is a methodology, to assess environmental burdens of a product/function including all the phases it experiences, which makes it a perfect tool to determine environmental burdens of renewable energy systems due to their considerably lower impacts during operation. In this study, LCA of an energy farm, constituted of multi-use offshore platforms was executed. Results showed manufacturing of the platform is the main source of pollution. In the manufacturing phase; fixed, moving and mooring parts are the main contributors and the WECs make a minor contribution. Material consumption is the main source for burdens during the life cycle of the system hence recycling ratios considered at the end of life scenarios affect the overall results. Implementation of multi-use floating concept to different locations gives various results changing with the capacity factor and the distances. The comparison between semi-submersible system and the spar platform ended up with comparable results both in terms of environmental burdens and material consumption.
Domaine de référence : EMR
Auteur Elginoz Nilay, Bas Bilge
Année de parution : 2017.
Mots-clés : Life Cycle Assessment, Marine renewable energy, Multi-use offshore platform, Wave energy, Wind energy.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Autonomous wind turbine blades cleaning system

Résumé : Wind Turbine Blade cleaning is essential to remove the contamination buildup on the blades, which otherwise deforms the shape of the airfoil and reduces the power production by 20%–30%. The contamination is mainly due to soil deposit, filth, bat carcasses and dead bugs deposits, on turbine blades. There are no efficient and automatic ways for cleaning the blades. This paper presents an Autonomous Wind Turbine Blades Cleaning System (ABC) designed to address the issue in entirely an automatic way. The proposed system is autonomous and “smart” in that it can: self-schedule the cleaning roster considering specifically the local atmospheric conditions as well as utility's system demand dynamics, commence the cleaning operation autonomously, with no human interaction at all, executes the post-cleaning log and informs the operation center in a routine manner, and alerts the Operations Center in case immediate attention is needed. The proposed system is physically installed onto the turbine tower and programmed to operate according to the industries best practices established in the field so far.
Domaine de référence : EMR
Auteur Yaqub R., Heidary K.
Année de parution : 2017.
Mots-clés : autonomous cleaning, Blades, cleaning, cleaning assembly, Poles and towers, Reservoirs, Sensors, wind turbine blades, Wind turbines.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Marine Renewable Energy in the Mediterranean Sea : Status and Perspectives

Résumé : In this work, an extended overview of the marine renewable energy in the Mediterranean Sea is provided as regards current status, potential problems, challenges, and perspectives of development. An integrated and holistic approach is necessary for the economic viability and sustainability of marine renewable energy projects; this approach comprises three different frameworks, not always aligned, i.e., geotechnical/engineering, socio-economic, and environmental/ecological frameworks. In this context, the geomorphological, climatological, socio-economic, and environmental/ecological particularities of the Mediterranean basin are discussed, as they constitute key issues of the spatial context in which marine renewable energy projects are to be implemented. General guidelines for the sustainable development of marine renewable energy in the Mediterranean are also provided.
Domaine de référence : EMR
Auteur Soukissian Takvor H., Denaxa Dimitra, Karathanasi Flora, Prospathopoulos Aristides, Sarantakos Konstantinos, Iona Athanasia, Georgantas Konstantinos, Mavrakos Spyridon
Année de parution : 2017.
Mots-clés : Marine renewable energy, Marine spatial planning, Mediterranean Sea, Ocean energy, Offshore wind energy, roadmap for marine energy development.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Experimental results of a multimode monopile offshore wind turbine support structure subjected to steep and breaking irregular waves

Résumé : We present experimental data from MARIN on a bottom-fixed offshore wind turbine mounted on a monopile in intermediate water depth subjected to severe irregular wave conditions. Two models are analysed: the first model is fully flexible and its 1st and 2nd eigenfrequencies and 1st mode shape are representative of those of a full-scale turbine. This model is used to study the structural response with special focus on ringing and response to breaking wave events. The second model is stiff and is used to analyse the hydrodynamic excitation loads, in particular the so-called secondary load cycle. The largest responses are registered when the second mode of the structure is triggered by a breaking wave on top of a ringing response. In such events, the quasi-static response accounts for between 40 and 50% of the total load, the 1st mode response between 30 and 40%, and the 2nd mode response up to 20%. A statistical analysis on the occurrences and characteristics of the secondary load cycle shows that this phenomenon is not directly linked to ringing.
Domaine de référence : EMR
Auteur Suja-Thauvin Loup, Krokstad Jørgen R., Bachynski Erin E., de Ridder Erik-Jan
Année de parution : 2017.
Mots-clés : Experimental hydrodynamics, Modal decomposition, Monopile, Offshore wind turbine, Ringing, Slamming.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Powering an island system by renewable energy—A feasibility analysis in the Maldives

Résumé : Water and energy supply systems are essential parts of the infrastructure on islands. For small islands that are far from continents, water shortage is usually the main constraint on economic and social development. In order to maintain island water security, desalination plants are built to supply fresh water. The plants need a great deal of energy, which increases demand for energy and the cost of transportation. Thus, it is necessary to design a new island system driven by renewable energy. This study investigated the existing type of water and energy supply systems in some typical islands of the world, and analyzed their advantages and disadvantages. The energy supply systems can be classified into three categories: imported conventional energy supply system (ICESS); imported conventional energy & renewable energy supply system (ICE&RESS); and integrated energy supply system (IESS). Water supply systems can also be classified into three categories: imported water supply system (ImWSS); imported water and unconventional water supply system (IW&UWSS); and integrated water supply system (InWSS). The nexus of energy and water is very complicated on islands. This paper presents a framework for an interconnected energy and water system on an island. The new framework reveals a roadmap from “full input of energy & water (FIEW)” through “semi-input of energy & water (SIEW)” to “zero input of energy & water (ZIEW)”, which leads an island's energy and water resources to become gradually independent from the mainland. The new framework also reduces transportation costs and carbon emissions. The proposed framework is applied to the Maldives to aid design of a renewable energy-driven water supply system. The characteristics and mutual adaptability of three types of renewable energy (solar, wind, and biomass energy) and water supply systems is discussed. The results show that a ZIEW system can be realized in the Maldives with a reduction in the cost of renewable energy. ZIEW system has great potential for application in island regions in the future.
Domaine de référence : EMR
Auteur Liu Jiahong, Mei Chao, Wang Hao, Shao Weiwei, Xiang Chenyao
Année de parution : 2017.
Mots-clés : Energy supply system, Island, Mutual adaptability, Renewable energy, Water resources, Water supply system.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Mounting for a tidal turbine

Résumé : A marine turbine and tower combination in which the turbine is mountable on the tower, The turbine has a co-operating member to interact with the tower to enable the turbine to be mounted on the tower in a pre-determined alignment. In one arrangement, the support tower comprises a substantially horizontal thruster plate mounted on top of the tower. The thruster has a central aperture to receive a downwardly directed stud on the turbine the thruster plate providing lateral support for the turbine. The stud has a vertical reaction interface around a lower part of the stud which is supported vertically by a reaction ring mounted on the tower.
Domaine de référence : EMR
Auteur Adshead Clive, Bromley Peter, Elkington Paul
Année de parution : 2017.
Type de document : Brevet.
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A risk assessment methodology for combining marine renewables with other blue economy activities via multi-use of spaces and platforms

Résumé : The future growth of maritime activities may be limited due to competition for space as coastal areas become overcrowded. This has led to interest in promoting more efficient and sustainable use of the sea and its resources through the sharing of space. The MARIBE (MARine Investment for the Blue Economy) project investigated the potential of combining marine renewable energy technologies with other emerging industries. The project assessed potential combinations, and identified challenges including the perception of risk due to the combination of new technologies. This work documents the methodology used to assign the risks to various potential combination projects within the blue economy, and applies it to one of the MARIBE case studies: combining wave energy with aquaculture. A standardised methodology of risk assessment was developed comprising three core elements of the risk management process: risk identification, risk analysis and risk mitigation. This method could be applied to each potential project combination, allowing results to be directly comparable, and allowing all stakeholders to have a full understanding of the risks identified. By using a standardised methodology, critical risks could be identified and mitigated, allowing informed decisions to be made on the most suitable combination projects to pursue. The methodology can be applied to other combination projects within these sectors.
Domaine de référence : EMR
Auteur Williams Hannah, Masters Ian, Pletsas D, Callaway R, Blanch M, Dalton Gordon, Fuentes-Grünewald Claudio
Année de parution : 2017.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Influence of Composite Fatigue Properties on Marine Tidal Turbine Blade Design

Résumé : The structural design of marine tidal turbine blades is governed by the hydrodynamic shape of the aerofoil, extreme loadings and composite material mechanical properties. The design of the aerofoil, chord and twist distribution along the blade is generated to optimise turbine performance over its life time. Structural design gives the optimal layout of composite laminae such that ultimate strength and buckling resistance requirements are satisfied. Most structural design approaches consider only extreme static loads, with a lack of dynamic load-based fatigue design for tidal blades. Approaches for tidal turbine blade design based on dry and immersed composite material fatigue life are studied.
Domaine de référence : EMR
Auteur Jaksic Vesna, Kennedy Ciaran R., Grogan David M., Leen Sean B., Brádaigh Conchúr M. Ó
Année de parution : 2017.
Type de document : Chapitre de livre.
Source : Springer, Cham
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Hydrodynamic Impacts of a Marine Renewable Energy Installation on the Benthic Boundary Layer in a Tidal Channel

Résumé : Field measurements of the flow in the benthic boundary layer (BBL) of a tidal channel are presented which compare data collected in the wake of a marine renewable energy installation (MREI) with control data representative of the natural conditions. The results show significant flow modification in the wake of the MREI including a reduction in mean velocity, enhanced turbulence, and the breakdown of the natural structure and dynamics of the BBL. This study provides new information relevant to the environmental impact assessment of MREIs and to the design and consenting of marine renewable energy projects.
Domaine de référence : EMR
Auteur Fraser Shaun, Nikora Vladimir, Williamson Benjamin J., Scott Beth E.
Année de parution : 2017.
Mots-clés : ADV, benthic boundary layer, Hydrodynamic impact, Marine renewable energy, tidal channel, Turbulence, wake dynamics.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Investigation into the Capabilities of Linear Theory for Numerical Modelling of Wave-Body Interactions for a 2D Heaving Buoy - Application to Wave Energy Converters

Résumé : Numerical modelling of wave energy converters (WECs) is currently an area of interest within the marine renewable energy industry, due to its ability to streamline design processes and accelerate scientific understanding. The presented project investigates the capacity of linear potential flow theory to accurately model wave excitation of a 2D WEC buoy-section, identifying wave conditions under which computational fluid dynamics (CFD) become a more appropriate strategy. OpenFOAM® v1612+ is utilised to simulate fully non-linear, viscous wave-structure interactions for comparison with linear theory and experimental results. Regular waves are generated to study both fixed and floating body cases. Linear forces are compared with those computed during fixed body CFD simulations, the validity of which is investigated using wave flume experiments carried out in NTNU s Ladertanken wave flume facility. Experimental and numerical results show reasonable agreement. 1st harmonic CFD forces compare well with linear forces in cases where overtopping is not observed. 2nd harmonic loads are shown to have significant contributions to total forces. Floating body CFD simulations are carried out allowing heave response displacements to be obtained for comparison with linear theory predictions. For the tested cases, responses are dominated by 1st harmonics, making comparison with linear theory particularly interesting. Good agreement is seen between linear theory and CFD for wave frequencies far from the natural frequency in heave, however divergence is seen for steep waves close to resonance where overtopping is extensive.
Domaine de référence : EMR
Auteur Short David
Année de parution : 2017.
Type de document : Article de revue.
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Economic comparison of technological alternatives to harness offshore wind and wave energies

Résumé : The present paper compares in economic terms, four technological alternatives to use offshore renewable energies: floating offshore wind energy technology, floating offshore wave energy systems, floating offshore co-located systems and floating offshore hybrid systems. These alternatives are compared considering different locations and sizes of the farms. Studies such as this can be useful for planning strategies and decision-making, particularly to investors that have to decide if and how to develop and deploy particular technologies in deep waters. The results indicate that the best alternative considering the life-cycle cost and LCOE is the floating offshore wind energy technology. Floating offshore co-located systems have the second best result, being a better alternative than floating offshore wave energy devices or floating offshore hybrid systems.
Domaine de référence : EMR
Auteur Castro-Santos Laura, Martins Elson, Soares C. Guedes
Année de parution : 2017.
Mots-clés : co-located systems, floating offshore wind, hybrid devices, life-cycle cost, Marine renewable energy, Wave energy, WEC.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Design and research of a new type of installation equipment for offshore wind power turbine

Résumé : A new type of the installation equipment for offshore wind turbine is proposed. Its three dimensional model and mechanism are designed. The kinematical analysis and dynamic analysis are conducted. Finally, according to the fuzzy theory, the method of calculating fuzzy reliability of kinematical accuracy of mechanism of the installation equipment is given out.
Domaine de référence : EMR
Auteur Ma C., Zheng M., Liang R.
Année de parution : 2017.
Mots-clés : dynamics, fuzzy reliability, installation equipment, kinematics, offshore wind power.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Probabilistic Distribution of Mooring Line Tension for Floating Offshore Wind Turbine

Résumé : The probabilistic distribution analysis of the mooring line tension for the floating offshore wind turbine is performed in this paper. The OC3-Hywind-Spar with 5 MW baseline wind turbine presented by American National Renewable Energy Labor
Domaine de référence : EMR
Auteur Zhang Min, Wu Yanjian, Du Junfeng, Xu Yu
Année de parution : 2017.
Type de document : Article de colloque.
Source : International Society of Offshore and Polar Engineers
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Setting an agenda for biofouling research for the marine renewable energy industry

Résumé : Extensive marine growth on man-made structures in the ocean is commonplace, yet there has been limited discussion about the potential implications of marine growth for the wave and tidal energy industry. In response, the Environmental Interactions of Marine Renewables (EIMR) Biofouling Expert Workshop was convened. Discussions involved participants from the marine renewable energy (MRE) industry, anti-fouling industry, academic institutions and regulatory bodies. The workshop aimed to consider both the benefits and negative effects of biofouling from engineering and ecological perspectives. In order to form an agenda for future research in the area of biofouling and the marine renewable energy industry, 119 topics were generated, categorised and prioritised. Identified areas for future focus fell within four overarching categories: operation and maintenance; structured design and engineering; ecology; and knowledge exchange. It is clear that understanding and minimising biofouling impacts on MRE infrastructure will be vital to the successful development of a reliable and cost effective MRE industry.
Domaine de référence : EMR , Biocorrosion
Auteur Loxton J, Macleod AK, Nall CR, McCollin T, Machado I, Simas T, Vance T, Kenny C, Want A, Miller R
Année de parution : 2017.
Mots-clés : Biofouling, Marine growth, Renewable energy, tidal, wave.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Coupled Aero-Hydrodynamic Analysis on a Floating Offshore Wind Turbine Under Extreme Sea Conditions

Résumé : ABSTRACT To develop renewable energy, the offshore wind energy technology has become an attractive research field. Considering the coupling effect of the platform motions and aerodynamic loads, how to accurately simulate the aero-hydrodynamics of fl
Domaine de référence : EMR
Auteur Huang Yang, Wan Decheng, Hu Changhong
Année de parution : 2017.
Type de document : Article de colloque.
Source : International Society of Offshore and Polar Engineers
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Open sea OWC motions and mooring loads monitoring at BiMEP

Résumé : Despite the large number of wave energy converter concepts proposed over the past three decades, only a few field measurement datasets are available in the public domain. The sparse nature of device performance and reliability data coupled with a general lack of design convergence means that technological and economic progress within the sector is fragmented. Fundamental to ensuring device efficiency and survivability is the acquisition of long-term, open sea, device and mooring system response data, combined with comprehensive numerical modelling. With mooring systems representing approximately 10% of marine renewable energy device CAPEX, the evolution of shared mooring systems and the use of novel materials with load reduction capabilities represent clear strategies to achieve more favourable project finances. This paper will report on design of the mooring load monitoring system as well as preliminary analysis of several load cases identified from field data recorded during the winter of the first deployment. Comparisons are made to numerical simulations of the device and mooring system subjected to representative environmental conditions. The measured mooring line tensions also provide operational design criteria (i.e. load capacity and durability requirements) for two elastomeric tethers which will replace the polyester ropes currently used in the seaward catenary lines.
Domaine de référence : EMR
Auteur Weller S. D., Parish D., Gordelier T., de Miguel Para B., Garcia E. A., Goodwin P., Tornroos D., Johanning L.
Année de parution : 2017.
Type de document : Article de colloque.
Source : EWTEC
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An Advanced Extreme Environment Wireless Telemetry System for Turbine Blade Instrumentation

Résumé : As advanced natural gas power generation systems evolve, the thrust for increased efficiencies and reduced emissions results in increasingly harsh conditions inside the turbine environment. These high temperatures, pressures, and corrosive atmospheres result in accelerated rates of degradation, leading to failure of turbine materials and components. Wolfspeed, A Cree Company, Siemens Energy and Siemens Corporate Technology, in collaboration with the DoE's National Energy Technology Laboratory (NETL), are developing a reliable and long-term monitoring capability in the turbine hot gas path in the form of novel ceramic based thermocouples and wide band gap instrumentation electronics that will contribute to the overall reliability of gas turbines. When equipped with better monitoring and controls, power plants can operate with increased fuel-burning efficiency, improved process dynamics and gas concentrations, and increased overall longevity of the power plant components. This will result in increased turbine availability and a reduction in outages and maintenance costs. The technology being developed in this program is based upon advanced techniques and innovations in nearly every aspect of high temperature electronics, including materials, subcomponents, semiconductors, electronic packaging, and system integration. The environment in which this wireless system must operate has continuous g-loads on the order of 16,000g, and temperatures exceeding 400 °C. This paper will specifically discuss the background and motivation for the high temperature instrumentation system, and will explain the high-level electrical system, the construction of the instrumentation package, the techniques utilized for integration onto rotating components, as well as the wireless power and data transmission systems. In addition to the electrical and mechanical design, this paper will also discuss results from laboratory bench testing as well as heated spin rig testing. Finally, this paper will highlight the future direction of the instrumentation system evolution, with a final objective of insertion into Siemens natural gas turbine power plants.
Domaine de référence : EMR
Auteur Fraley John R., Sparkman Brett, Minden Stephen, McConkey Joshua
Année de parution : 2017.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Influence of the Wake Effect on Electrical Dynamics of Commercial Tidal Farms : Application to the Alderney Race (France)

Résumé : The extraction of tidal energy is one of the most promising Marine Renewable Energies (MRE) and is nowadays in a preindustrial phase. The Alderney Race (France) capitalizes a resource estimated between 5 and 14 TWh/year. This great tidal resource attracts tidal energy developers. Harnessing the high potential of the Alderney Race requires deploying numerous turbines in arrays.
Domaine de référence : EMR
Auteur Brutto O. A. L., Barakat M., Guillou S. S., Thiébot J., Gualous H.
Année de parution : 2017.
Mots-clés : Alderney race, Couplings, Electric potential, hydrodynamic data, Maintenance engineering, Tidal energy, tidal farm electrical model, voltage dip, Voltage fluctuations, wake effect, Wind turbines.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Modelling the effect of large arrays of tidal turbines with depth-averaged Actuator Disks

Résumé : The Actuator Disk concept is suitable to simulate the flow interactions between tidal turbines. As the computational expense of AD simulations is too large for applications at regional scale, the “bed friction” method is generally preferred. It consists in applying an enhanced drag over the tidal farm area. The main drawback is that the flow around each turbine is not resolved and that the flow interactions between the turbines’ wakes are neglected. The extent to which this simplification affects the accuracy of the large scale flow is not well understood. Here, we propose a methodology for representing large arrays of tidal turbines in Shallow Water Equations solvers. It consists in representing individual turbines as small areas where a sink momentum term is applied. The sink term is calculated from the vertical integration of the force exerted on an AD. After validating the model, we apply the methodology to simulate the effect of 45 turbines placed in the Alderney Race. The results are compared to the results obtained with the “bed friction” method. The two approaches give similar results because the hydrodynamics conditions of the Alderney Race favor the mixing of the wakes which prevents the flow interactions between the turbines.
Domaine de référence : EMR
Auteur Thiébot Jérôme, Guillou Sylvain, Nguyen Van Thinh
Année de parution : 2016.
Mots-clés : Actuator Disk, Alderney race, Numerical modelling, Raz blanchard, Regional scale, Tidal stream turbine.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Hydroelastic Analysis of Multi-Unit Floating Offshore Wind Turbine Platform (MUFOWT)

Résumé : Along with global warming threat, importance of renewable energy development is on the rise for global sustainable development. To amplify productivity of ocean renewable energy, a multi-unit floating offshore wind turbine platform (MUFOWT)
Domaine de référence : EMR
Auteur Kang HeonYong, Kim Moo-Hyun, Kim Kyung-Hwan, Hong KeyYong
Année de parution : 2017.
Type de document : Article de colloque.
Source : International Society of Offshore and Polar Engineers
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Feasibility Analysis of Floating Offshore Wind Turbine With Single Point Mooring System

Résumé : During power generation, the rotor of wind turbine needs to be aligned with the incoming wind for optimal energy production. On state-of-the-art upwind wind turbines, this step is usually achieved through the yaw control system in the nacel
Domaine de référence : EMR
Auteur Li Yan, Tang Yougang, Zhu Qiang, Qu Xiaoqi, Zhai Jiawei, Zhang Ruoyu
Année de parution : 2017.
Type de document : Article de colloque.
Source : International Society of Offshore and Polar Engineers
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Energy management in a tidal farm. Application to the Alderney Race (Raz Blanchard) Gestion de l’énergie dans un parc d’hydroliennes : Application au Raz Blanchard

Résumé : Interest in Marine Renewable Energies (MREs) is growing worldwide because they are seen as a potential resource to harness for the production of electric power. Furthermore, they could contribute to the reduction of the emission of greenhouse gases. Almost two-third of the Earth is covered by oceans, so that a huge amount of energy could be produced. Among the different types of MRE (i.e. thermal energy, chemical energy, biological energy, wave and tidal energy) tidal current energy seems to be the most attractive. Firstly, contrarily to wind energy, it is highly predictable. Secondly, the tidal resource is generally characterized by a low variation in direction. Finally, tidal energy has a high potential that could allow increasing the energy mix in Europe. France has the second production potential of electrical energy from MREs, behind the UK. In fact, French production potential is estimated between 5 and 14 TWh/year. The Alderney Race (Raz Blanchard in French), situated between the Alderney Island and La Hague Cape (France), capitalizes about half of the national resource (Bahaj and Myers, 2004, Myers and Bahaj, 2005). The French premier announced in that the Government will support two projects consisting in the installation of two little pilot tidal turbines farms in the Alderney Race. These projects will represent a decisive step towards setting up pre-commercial and commercial operations in tidal energy. Two of the main issues for the commercial development of tidal farms is the optimization of the turbines layout for maximizing the producible energy and the energy management for optimizing the energy production. These aspects depend on the wake effect and on the control of the electrical conversion chain. One of the factor that influences the producible energy of a park is its layout. In fact, optimized positions of turbines allows reducing the so called wake effect, which is a natural phenomenon consisting on increased values of turbulence and a reduced flow velocity behind a tidal turbine (Stallard et al., 2015). Nowadays, the wake effect is analyzed mainly with numerical methods that are highly precise but computationally expensive (Funke et al., 2014). After that the producible energy has been achieved, the electrical production has to be improved. This aim can be carried out through the correct modeling of the electrical components (Zhou et al., 2015). One time the electrical chain has been implemented, the control system can be tested to allow the system working at optimal operation points. The objectives of this dissertation are the development of an optimization tool to maximize the producible energy of a tidal farm and the improvement of the control of the electrical chain. To this scope, in Chapter I the state of art about the analysis of tidal farms is presented. In Chapter II, an analytical model of the wake effect in a park is developed and validated. Moreover, a parametric study of the tidal farm layout is applied to the Alderney Race. In Chapter III, different types of optimization algorithms are compared to solve the tidal farm layout optimization problem. The optimization tool (in which the analytical wake model is employed) is presented and tested in one site in the Alderney Race. Finally, in Chapter IV all the components of the electrical conversion chain are modelled. Furthermore, different strategies to maximize the electrical production of the tidal farm are compared. A complete electrical model including all the components and the control are implemented to test the dynamic behavior of a hypothetical tidal farm subject to the changes in tidal speed in a site in the Alderney Race and to grid disturbances (for example, voltage dips)
Domaine de référence : EMR
Auteur Brutto Ottavio Angelo Lo
Année de parution : 2016.
Type de document : Rapport.
Source : Unpublished
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Stress Analyses of the Offshore Wind Turbine Structures Subjected to Ocean Waves

Résumé : Two common offshore wind turbine structures, the monopile type and the jacket type, subjected to ocean wave load were analyzed using finite element simulations. The FEM models were built in ABAQUS, and applied the load combinations consisti
Domaine de référence : EMR
Auteur Lin Yu-Yun, Peng Ssu-Yu
Année de parution : 2017.
Type de document : Article de colloque.
Source : International Society of Offshore and Polar Engineers
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Energetic Macroscopic Representation of Marine Current Turbine System with Loss Minimization Control

Résumé : This paper presents the detailed modeling and the Energetic Macroscopic Graphical Representation of the Marine Current Turbine (MCT) System. The studied marine current turbine system consists of 1.5 MW Fixed Pitch Tidal Turbine, Permanent Magnet Synchronous Generator; AC-DC fully controlled machine side converter, DC link, DC-AC fully controlled grid side converter, connection cables, transformer, and the central grid. The control of each converter is designed based on defining the tuning chain as a part of the system energetic macroscopic representation. The machine side converter control depends on the torque control maximum power point tracking and the generator loss minimization (Output Maximization) techniques to enhance the overall efficiency when the system runs under the rated marine current speed. The control mode is changed to the rated power limiting mode when the system runs above the base speed. The grid side converter is controlled to stabilize the DC link voltage within a certain range beside the reactive power control. The proposed control strategies are evaluated based on the model results by using the real data of The Alderney Race (Raz Blanchard in French) marine site.
Domaine de référence : EMR
Auteur Barakat M. R., Tala-Ighil B., Chaoui H., gualous h, Slamani Y., Hissel D.
Année de parution : 2017.
Mots-clés : Energetic Macroscopic Representation (EMR), Fixed Pitch Direct Drive (FPDD), Generators, Integrated circuit modeling, Marine Current Turbine (MCT), Mathematical model, Maximum power point trackers, Maximum Power Point Tracking (MPPT), Minimization, Permanent magnets, Reactive Power Control (RPC), Turbines.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

DYNAMIC-PERFORMANCE-ANALYSIS-OF-A-NEW-SEMI-TYPE-FLOATING-OFFSHORE-WIND-TURBINE-PLATFORM

Résumé : A new semi type floating offshore wind turbine platform called Y-Wind is developed to support a 5MW wind turbine, considering various design aspects from engineering through to installation, which can reduce the CAPEX. The platform is designed to achieve the integration of the tower and rotor to the platform at quayside in a US shipyard. Also a proper lightship draft is considered in the early platform design phase to enable wet-tow from the yard to the installation site with no dedicated extra equipment, as the majority of shipyards in US east and west coasts may not be able to accommodate floating wind platforms with deep lightship draft. The Y-Wind platform with damping plates consists of four columns having the same diameter. No deck structures and braces are used. Center column supports a 5MW wind turbine and three other offset columns connected to the center column by respective pontoon are optimally placed such that the hydrostatic stability and minimal static heeling angle by wind turbine peak thrust are ensured. The platform is moored with three catenary lines with a sufficient length to avoid the uplift at the anchor. Time domain coupled simulations under typical US offshore metocean conditions are conducted to assess the platform dynamic responses including motions, accelerations, and mooring tensions for the design load cases of the power production, 50-yr extreme and 500-yr survival conditions in accordance with ABS floating offshore wind turbine guide. The present design is checked against the ABS design criteria and confirmed to comply with the design requirements. Also significant reductions of motions are observed due to the damping plates, which also results in reducing the mooring line tensions. Preliminary global structural analysis was performed to assess the stress ratios of the primary structures.
Domaine de référence : EMR
Auteur Boo,Sung
Année de parution : 2017.
Type de document : Article de revue.
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The application of electromagnetic fields to the control of the scaling and biofouling of reverse osmosis membranes - A review

Résumé : Scaling and biofouling are two major problems in the operation of reverse osmosis (RO) membranes. A variety of control measures are employed in practice, including the use of pulsed electromagnetic fields (EMF), which can avoid the use of chemical anti-fouling agents (e.g. halogen-based biocides) that may be toxic to humans or the environment. This is a fairly recent and controversial technology and, from the available documentation and literature, it is clear that the scientific basis for its purported effectiveness is not yet firmly established, although some studies suggest that beneficial effects could be possible. In particular, the various conditions under which EMF technologies are likely to be effective for real world applications have not been scientifically established. This review collates the relevant literature on the problem of scaling and biofouling in RO membranes and heat exchangersystems (e.g. cooling towers), with a particular focus on the application of pulsed EMF technologies, including the broad documentation, relevant scientific studies, proposed mechanisms of action and further research directions. This review demonstrates that a lot more systematic scientific research is needed in order to validate the application and commercialization of EMF technologies as a pretreatment to control fouling in RO membrane systems.
Domaine de référence : EMR
Auteur Piyadasa Chathuri, Ridgway Harry F., Yeager Thomas R., Stewart Matthew B., Pelekani Con, Gray Stephen R., Orbell John D.
Année de parution : 2017.
Mots-clés : Biofouling, cleaning, Electromagnetic fields, Pulsed electric fields, Scaling.
Type de document : Article de revue.
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Strength Analysis of a Large-Size Supporting Structure for an Offshore Wind Turbine

Résumé : The offshore wind power industry is the branch of electric energy production from renewable sources which is most intensively developed in EU countries. At present, there is a tendency to install larger-power wind turbines at larger distances from the seashore, on relatively deep waters. Consequently, technological solutions for new supporting structures intended for deeper water regions are undergoing rapid development now. Various design types are proposed and analysed, starting from gravitational supports (GBS), through monopiles and 3D frame structures (jackets, tripods), and ending with floating and submerged supports anchored to the seabed by flexible connectors, including TLP type solutions.
Domaine de référence : EMR
Auteur Niklas Karol
Année de parution : 2017.
Type de document : Article de revue.
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Specialist Committee on Hydrodynamic Testing of Marine Renewable Energy Devices : final report and recommendations to the 27th ITTC

Résumé : This report addresses a number of key issues in the physical and numerical testing of marine renewable energy systems, including wave energy devices, current turbines, and offshore wind turbines. The report starts with an overview of the types of devices considered, and introduces some key studies in marine renewable energy research. The development of new ITTC guidelines for testing these devices is placed in the context of guidelines developed or under development by other international bodies as well as via research projects. Sites developed around the world for full-scale testing of Marine Renewable Energy Devices are discussed. Some particular challenges are introduced in the experimental and numerical modelling and testing of these devices, including the simulation of Power-Take-Off systems (PTOs) for physical models of all devices, approaches for numerical modelling of devices, and the correct modelling of wind load on offshore wind turbines. Finally issues related to the uncertainty in performance prediction from test results are discussed. Definition of the stages of a device test program – Technology Readiness Level (TRL) definition <li> Summary of testing requirements / challenges for device type (ocean v tidal current, rotating v non-rotating, shallow v deep deployment, rigid mounting v flexible mooring) and device development stage; <li> Coupling between model scale, choice of facility, device type, and experiment stage. <li> Identification of common error sources associated with small to field-scale testing with guidelines on impact on test success, interpretation of test results and how to quantify and report measurement error.</ul>
Domaine de référence : EMR
Auteur Day S., Penesis I., Babarit A., Fontaine A., He Y., Kraskowski M., Murai M., Salvatore F., Shin H. K., Devices Specialist Committee on Hydrodynamic Modelling of Offshore Renewable Energy
Année de parution : 2017.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Tidal Energy : The benthic effects of an operational tidal stream turbine

Résumé : The effect of modified flow on epifaunal boulder reef communities adjacent to the SeaGen, the world's first grid-compliant tidal stream turbine, were assessed. The wake of the SeaGen was modelled and the outputs were used in conjunction with positional and substrate descriptor variables, to relate variation in epifaunal community structure to the modified physical environment. An Artificial Neural Network (ANN) and Generalised Linear Model (GLM) were used to make predictions on the distribution of Ecological Status (ES) of epifaunal communities in relation to the turbulent wake of the SeaGen. ES was assigned using the High Energy Hard Substrate (HEHS) index. ES was largely High throughout the survey area and it was not possible to make predictions on the spatial distribution of ES using an ANN or GLM. Spatial pattern in epifaunal community structure was detected when the study area was partitioned into three treatment areas: area D1; within one rotor diameter (16 m) of the centre of SeaGen, area D2; between one and three rotor diameters, and area D3; outside of three rotor diameters. Area D1 was found to be significantly more variable in terms of epifaunal community structure, bare rock distributions and ES than areas D2 and D3.
Domaine de référence : EMR
Auteur O'Carroll J. P. J., Kennedy R. M., Creech A., Savidge G.
Année de parution : 2017.
Type de document : Article de revue.
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Underwater operational noise level emitted by a tidal current turbine and its potential impact on marine fauna

Domaine de référence : EMR
Auteur Lossent Julie, gervaise cedric, Iorio Lucia D., Folegot Thomas, Clorennec Dominique, Lejart Morgane
Année de parution : 2017.
Type de document : Article de revue.
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Experimental investigation on mooring loads and motions of a TLP floating wind turbine

Résumé : This paper investigates numerically and experimentally the behaviour of a Tension Leg Platform (TLP) floating wind turbine, under regular waves. The physical model tests have been performed at the Danish Hydraulic Institute (DHI) offshore wave basin. The general aim of this work is to form an accurate set of data, basically consisting in incident waves, 3D wave oscillation and mooring loads that may be used as a possible term of reference for numerical models. The paper provides a thorough description of the geometrical and dynamic characteristics of the floating body, and the results in terms of the incident waves interpreted on the basis of an array of resistive wave gauges, the displacements as observed by a tracking camera system (surge, sway, heave and roll, pitch, yaw), and the loads measured by a load cell located at the fairlead of the anchoring lines, simulating in the physical model scale the tendons characteristics in full scale. Experimental results are given in graphical form for the case of regular wave conditions. Corresponding numerical results that have been obtained using home developed software for the hydrodynamic- and the static- and dynamic-analysis of the mooring lines (HAMVAB [1] and STATMOOR [2], respectively) compare well with the experimental data. STATMOOR [2] is capable to handle the static analysis of extensible mooring lines made of several segments each of them with different geometrical properties and with attached submerged buoys along them.
Domaine de référence : EMR
Auteur Mazarakos T. P., Mavrakos S. A.
Année de parution : 2017.
Mots-clés : Aerodynamics, Blades, Experiments, Load modeling, Mooring Loads, Motions, Rotors, Tension Leg Platform, Velocity control, Wind speed, Wind turbine, Wind turbines.
Type de document : Article de colloque.
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Semi-active control of monopile offshore wind turbines under multi-hazards

Résumé : The present paper studies the control of monopile offshore wind turbines subjected to multi-hazards consisting of wind, wave and earthquake. A Semi-active tuned mass damper (STMD) with tunable natural frequency and damping ratio is introduced to control the dynamic response. A new fully coupled analytical model of the monopile offshore wind turbine with an STMD is established. The aerodynamic, hydrodynamic and seismic loading models are derived. Soil effects and damage are considered. The National Renewable Energy Lab monopile 5 MW baseline wind turbine model is employed to examine the performance of the STMD. A passive tuned mass damper (TMD) is utilized for comparison. Through numerical simulation, it is found that before damage occurs, the wind and wave induced response is more dominant than the earthquake induced response. With damage presence in the tower and the foundation, the nacelle and the tower response is increased dramatically and the natural frequency is decreased considerably. As a result, the passive TMD with fixed parameters becomes off-tuned and loses its effectiveness. In comparison, the STMD retuned in real-time demonstrates consistent effectiveness in controlling the dynamic response of the monopile offshore wind turbines under multi-hazards and damage with a smaller stroke.
Domaine de référence : EMR
Auteur Sun C.
Année de parution : 2018.
Mots-clés : Damage, Multi-hazards, Offshore wind turbine, Semi-active control, Vibration and damping.
Type de document : Article de revue.
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Energy storage solutions for offshore wave and tidal energy prototypes

Résumé : This paper investigates the motivations for energy storage solutions for offshore Wave Energy Converters (WEC) and tidal energy prototypes. It examines the power and energy storage solutions on offer for developers to aid them during the design stage. Energy storage solutions examined include lead acid batteries, lithium ion batteries, supercapacitors, lithium ion capacitors and diesel for diesel generators. A focus is placed on key installation, operation and maintenance requirements associated with the apparent suitable technologies which are often overlooked. A case study examining a tidal developer's energy storage needs is then presented.
Domaine de référence : EMR
Auteur Murray D. B., Gallagher P., Duffy B., McCormack V.
Année de parution : 2017.
Mots-clés : AGM battery, battery, Capacitors, energy storage, Generators, Lead acid batteries, lead acid battery, lithium ion battery, Maintenance engineering, Prototypes, tiday energy, VRLA battery, Wave energy converter.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Verification of a Rapid Mooring and Foundation Design Tool

Résumé : Marine Renewable Energy (MRE) devices require mooring and foundation systems that are suitable in terms of device operation, are robust and also cost effective. In the initial stages of mooring and foundation development a large number of possible configuration permutations exist. Filtering of unsuitable designs is possible using information specific to the deployment site (i.e. bathymetry, environmental conditions) and device (i.e. mooring and/or foundation system role and cable connection requirements). The identification of a final solution requires detailed analysis, which includes load cases based on extreme environmental statistics following certification guidance processes. Static and/or quasi-static modelling of the mooring and/or foundation system serves as an intermediate design filtering stage enabling dynamic time-domain analysis to be focused on a small number of potential configurations. Mooring and foundation design is therefore reliant on logical decision making throughout this stage-gate process. The open-source DTOcean (Optimal Design Tools for Ocean Energy Arrays) Tool includes a Mooring and Foundation (MF) module, which automates the configuration selection process for fixed and floating wave and tidal energy devices. As far as the authors are aware this is one of the first tools to be developed for the purpose of identifying potential solutions during the initial stages of MRE design. Whilst the MF module does not replace a full design assessment, it provides in addition to suitable configuration solutions, assessments in terms of reliability, economics and environmental impact. This paper provides insight into the solution identification approach used by the module and features the verification of both the mooring system calculations and the foundation design using commercial software. Several case studies are investigated; a floating wave energy converter and several anchoring systems. It is demonstrated that the MF module is able to provide device and/or site developers with rapid mooring and foundation design solutions to appropriate design criteria.
Domaine de référence : EMR
Auteur Weller S. D., Hardwick J., Gomez S., Heath J., Jensen R., McLean N., Johanning L.
Année de parution : 2017.
Type de document : Article de revue.
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Fluctuating loads on a tidal turbine due to velocity shear and turbulence : Comparison of CFD with field data

Résumé : Fluctuating loads on tidal turbines are important for fatigue analysis and there is limited information or simulation available for full-scale conditions. Here, CFD simulations have been performed for a geometry-resolved full-scale tidal-stream turbine and compared with experimental data from a 1 MW machine deployed at the EMEC test site. Initially, Reynolds-averaged Navier-Stokes (RANS) and large-eddy simulations (LES) were performed using an inflow mean velocity profile representative of the site but low inflow turbulence. Mean blade pressures were similar for the two types of turbulence closure and yielded mean power coefficients comparable with measurements. Then, to simulate the effect of turbulence on loads, LES with synthetic turbulence prescribed at inlet was employed. For these simulations, inflow profiles of mean velocity, Reynolds stresses and length scales were determined from a precursor channel-flow simulation, with additional factoring of stresses and length scales to match hub-height conditions measured on site. Fluctuations in thrust, power and blade bending moment arise cyclically from onset mean velocity shear and the blocking effect of the support tower and over continuous spectral ranges from blade-generated turbulence, approach-flow turbulence and waves. LES simulations with realistic inflow turbulence satisfactorily reproduced the relative spectral distribution of blade bending moments in low-wave conditions.
Domaine de référence : EMR
Auteur Ahmed U., Apsley D. D., Afgan I., Stallard T., Stansby P. K.
Année de parution : 2017.
Mots-clés : Computational fluid dynamics, Large-eddy simulation, Load spectra, Synthetic-eddy modelling, Tidal-stream turbine.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Wave Energy Converters and Tidal Energy Converters Road to Commercial Viability

Résumé : Abstract This paper will report on the status of the US power industry today and how close some Marine Energy Converters (MECs) options are to becoming commercially viable in the near future. The paper provides an overview of the rules and regulatio
Domaine de référence : EMR
Auteur Gehring Donald H.
Année de parution : 2017.
Type de document : Article de colloque.
Source : Offshore Technology Conference
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Design of an Energy Storage System ACAES Applied to Marine Renewable Energy : Study Case Based on Energy Integration Approach

Résumé : Abstract Marine energies (including wind turbine, tidal current and wave energy) are now recognized not only as high potential energy sources, but also as a significant and maturing energy market. Nevertheless, renewable marine energies are highly i
Domaine de référence : EMR
Auteur Chassé C., Lemois F., Chilloux D., Langeard O.
Année de parution : 2017.
Type de document : Article de colloque.
Source : Offshore Technology Conference
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Plus de références EMR


• Biocorrosion icone-flux-rss

Conducting polymer/bio-material composite coatings for corrosion protection

Résumé : Present study demonstrates a facile in situ oxidative copolymerization method to synthesize conducting copolymer composites in aqueous chitosan medium. The development of poly(aniline-co-o-toluidine)–chitosan–SiO2/epoxy composite coatings were carried out by thermal curing of the spray-coated mild steel substrates. FT-IR analysis, XRD studies, SEM and HR-TEM evidenced that the composite has synergistically integrated properties of the copolymer and the SiO2 nanoparticles. The electrochemical analyses of the coatings in 3.5% NaCl solution manifest an efficient role of copolymer composite in the remarkable improvement of the corrosion resistance of the substrate. The analyses involve Tafel polarization and electrochemical impedance spectroscopy (EIS) studies. The corrosion inhibition property of conducting copolymers, the film forming ability of chitosan, and robustness of SiO2 nanoparticles kept the corrosion rate of the coatings significantly low, under highly corrosive conditions. Mild steel coated with 3.0% loading of copolymer composite coating demonstrated very low corrosion current density (icorr) and significantly high pore resistance (Rpore).
Domaine de référence : Biocorrosion
Auteur Sambyal Pradeep, Ruhi Gazala, Mishra Monu, Gupta Govind, Dhawan Sundeep K.
Année de parution : 2017.
Mots-clés : copolymer composites, EIS, polymer coatings, Tafel polarization.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Oxygen-reducing biocathodes designed with pure cultures of microbial strains isolated from seawater biofilms

Résumé : Microbial biofilms that form on metallic surfaces in natural seawater are known to generate efficient oxygen-reducing cathodes. The microbial catalysis of oxygen reduction is a major mechanism of corrosion in marine aerobic environments; it can also be exploited to develop biocathodes for microbial fuel cells. In the latter case, seawater biocathodes have the great advantage of operating in high-salinity electrolytes. Four bacterial strains (Pseudoalteromonas sp., Marinobacter sp., Roseobacter sp., Bacillus sp.) were isolated from an oxygen-reducing biocathode formed in natural seawater. 16S rDNA pyrosequencing analysis showed that the strains isolated were representative of the microbial community that composed the initial multispecies biocathode, which was dominated by Gamma-Proteobacteria. Each strain was able to form oxygen-reducing monospecies biocathodes both in natural seawater and in a synthetic medium with the same salinity. Stable current densities of 40 mA m−2 were produced under constant applied potential (−0.30 V/SCE) and up to 0.8 A m−2 was recorded at −0.60 V/SCE. This work provides the first description of monospecies biocathodes designed with salinity-tolerant strains and offers an experimental model to advance the investigation of the microbiological and biochemical processes on seawater biocathodes in well-controlled conditions.
Domaine de référence : Biocorrosion
Auteur Debuy Sandra, Pécastaings Sophie, Bergel Alain, Erable Benjamin
Année de parution : 2015.
Mots-clés : Biocathode, Gamma-Proteobacteria, Marine bacteria, Microbial fuel cell, Oxygen reduction.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Improved antibacterial, antifouling and corrosion protective performance of epoxy coatings with poly(m-aminophenol)

Résumé : Poly(m-aminophenol) (PmAP) was prepared by oxidation polymerization of m-aminophenol in alkaline medium and characterized by scanning electron microscopy (SEM), FT-IR spectra, UV–visible absorption spectra and X-ray photoelectron spectroscopy. The antibacterial behavior of PmAP was characterized by stepwise dilution method, and the results demonstrate that the PmAP displayed excellent antibacterial property against both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis. Furthmore, epoxy coatings containing different amount of PmAP using cardanol-based phenalkamine as curing agent were prepared. The coatings containing PmAP exhibited higher antibacterial activity against Escherichia coli and Bacillus subtilis. In addition, the antifouling property of the coatings was investigated by immersing the films in bacterial suspension for four days. The results showed that the coatings containing PmAP possessed high ability to inhibit the formation of biofilm which is the key process to prevent the occurrence of biofouling in the initial stage. Meanwhile, the coatings with PmAP possessed high corrosion protective performance shown by immersion tests in 12% NaCl solution monitored by the electrochemical impedance spectroscopy (EIS). The experimental results might give some new insight into designing and application of multifunctional materials used in the preparation of coatings.
Domaine de référence : Biocorrosion
Auteur Quan Xiaodong, Wang Jixiao, Zhao Song, Cai Wei, Wang Zhi, Wang Shichang, Cui Xianbao
Année de parution : 2018.
Mots-clés : Anticorrosion, Antifouling, Epoxy coatings, Poly(-aminophenol).
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Ennoblement, corrosion, and biofouling in brackish seawater : Comparison between six stainless steel grades

Résumé : In this work, six common stainless steel grades were compared with respect to ennoblement characteristics, corrosion performance and tendency to biofouling in brackish sea water in a pilot-scale cooling water circuit. Two tests were performed, each employing three test materials, until differences between the materials were detected. Open circuit potential (OCP) was measured continuously in situ. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements were conducted before and after the tests. Exposed specimens were further subjected to examinations by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), and the biofouling was studied using epifluorescence microscopy, quantitative polymerase chain reaction (qPCR) and high-throughput sequencing (HTP sequencing). The results revealed dissimilarities between the stainless steel grades in corrosion behaviour and biofouling tendency. The test material that differed from the most of the other studied alloys was grade EN 1.4162. It experienced fastest and most efficient ennoblement of OCP, its passive area shrank to the greatest extent and the cathodic reaction was accelerated to a significant degree by the development of biofilm. Furthermore, microbiological analyses revealed that bacterial community on EN 1.4162 was dominated by Actinobacteria, whereas on the other five test materials Proteobacteria was the main bacterial phylum.
Domaine de référence : Biocorrosion
Auteur Huttunen-Saarivirta E., Rajala P., Marja-aho M., Maukonen J., Sohlberg E., Carpén L.
Année de parution : 2018.
Mots-clés : Biofouling, Brackish sea water, Electrochemical measurements, Ennoblement, Microbially induced corrosion (MIC), Stainless steel.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Effects of biogenic H2S on the microbiologically influenced corrosion of C1018 carbon steel by sulfate reducing Desulfovibrio vulgaris biofilm

Résumé : The role of biogenic H2S in the microbiologically influenced corrosion (MIC) of carbon steel was investigated. Desulfovibrio vulgaris (ATCC 7757), a sulfate reducing bacterium, was tested against C1018 carbon steel in anaerobic vials with three different sizes, each filled with 40mL of ATCC 1249 culture medium, providing headspace volumes of 10mL, 85mL and 160mL, respectively for H2S to escape. Results showed that a larger headspace led to a lower H2S concentration in the culture medium, and this increased the sessile cell count and made the iron sulfide film thinner, resulting in increased MIC.
Domaine de référence : Biocorrosion
Auteur Jia Ru, Tan Jie Long, Jin Peng, Blackwood Daniel John, Xu Dake, Gu Tingyue
Année de parution : 2018.
Mots-clés : A. Carbon steel, B. SEM, B. Weight loss, C. Microbiological corrosion, C. Pitting corrosion.
Type de document : Article de revue.
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Interpreting microbiologically assisted cracking with Ee-pH diagrams

Résumé : Although many mechanisms have been proposed to explain the microbiologically assisted cracking (MAC) of steel and copper, a theoretical interpretation is necessary. In this paper, we attempt to give a theoretical interpretation of sulfate/nitrate reducing bacteria (SRB/NRB)-assisted cracking using Ee-pH diagrams. Under the combined actions of SRB/NRB and external stress, the cell potential (Ecell) and the corrosion current density of the corrosion reaction increase, such that the corrosion reactions become more thermodynamically favorable. This is the nature of MAC. Nitrate is a far more potent oxidant than sulfate, and thus, the NRB-assisted cracking of iron is a more thermodynamically favorable process than the SRB-assisted cracking. Furthermore, the thermodynamic interpretation is attempted to implicate into the classical stress corrosion cracking mechanisms of pipeline steel.
Domaine de référence : Biocorrosion
Auteur Wu Tangqing, Sun Cheng, Ke Wei
Année de parution : 2018.
Mots-clés : Ee-pH diagram, Microbiologically induced corrosion, Nitrate-reducing bacteria, Stress corrosion, Sulfate-reducing bacteria.
Type de document : Article de revue.
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A Fuzzy logic-possibilistic methodology for risk-based inspection (RBI) planning of oil and gas piping subjected to microbiologically influenced corrosion (MIC)

Résumé : Operating oil and gas installations are continuously subjected to attacks by a number of degrading mechanisms. In order to detect the presence and location of these attacks, installations need to be regularly inspected. Unfortunately, comprehensive inspection programs are quite expensive; hence, Risk-Based Inspection (RBI) methodology is often adopted to assist in the development of effective and efficient inspection programs. In order to account for a particular degradation mechanism in RBI analysis, inspection engineers need to know its likelihood of occurrence and its estimated rate of degradation. The complex natures of various degradation mechanisms make accurate prediction of the rates of corrosion in an operating plant rather difficult. Luckily, for developing a risk-based inspection (RBI) program, it is not necessary for a model to accurately estimate the degradation process over a wide range of conditions. Instead the requirement is for a practical model which is simple to use, flexible enough to reflect different sections' requirements, and able to incorporate field data. Microbiologically influenced corrosion (MIC) is one of the commonly encountered degradation mechanisms in offshore and onshore oil and gas installations. As with any other corrosion process, the prediction of likelihood of its initiation and its associated rate of corrosion is difficult to accurately model. A model based on a fuzzy logic framework and possibilistic approach may offer a simple yet flexible tool to assist engineers in developing their RBI programs. This paper presents a proposed methodology, based on a fuzzy logic framework, for estimating the rate of MIC corrosion in carbon steel static equipment, pipes and pressure vessels. The paper also presents a procedure based on possibility approach to calculating the possibility and necessity of failure. Finally, the paper presents a methodology for determining the optimum time for inspection.
Domaine de référence : Biocorrosion
Auteur Singh Maneesh, Pokhrel Marshal
Année de parution : 2018.
Mots-clés : Failure, Fuzzy logic, MIC, Oil and gas pipes, Possibilistic approach, Reliability, Structural integrity.
Type de document : Article de revue.
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Bibliometric Analysis of Microbiologically Influenced Corrosion (MIC) of Engineering Systems

Résumé : Managing Microbiologically Influenced Corrosion (MIC) is both an economic and technological challenge for the oil and gas industry. There are studies and data generated regarding the corrosion mechanism, microbial species involved and chemicals that may enhance/inhibit MIC. However, these data are diffuse, sometimes have contradictory conclusions and have ignored one or more key factors that drive MIC. This paper investigates the evolution of MIC knowledge in the past decades by conducting a bibliometric analysis of the literature. The paper also identifies current knowledge gaps and proposes future research directions. Although MIC mechanisms, monitoring and control have been active areas of research in recent years, linking microbial activities, the chemical environment (e.g. produced water lines vs. crude lines), and the corrosion mechanisms is still an important knowledge gap. The importance of a coordinated multidisciplinary approach to develop integrated knowledge, MIC mechanistic models and integration of these factors in effective decision-making is also discussed in this paper.
Domaine de référence : Biocorrosion
Auteur Hashemi Javad, Bak Nicholas, Khan Faisal, Hawboldt Kelly, Lefsrud Lianne, Wolodko John
Année de parution : 2017.
Type de document : Article de revue.
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Key Metabolites and Mechanistic Changes for Salt Tolerance in an Experimentally Evolved Sulfate-Reducing Bacterium, Desulfovibrio vulgaris

Résumé : Rapid genetic and phenotypic adaptation of the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough to salt stress was observed during experimental evolution. In order to identify key metabolites important for salt tolerance, a clone, ES10-5, which was isolated from population ES10 and allowed to experimentally evolve under salt stress for 5,000 generations, was analyzed and compared to clone ES9-11, which was isolated from population ES9 and had evolved under the same conditions for 1,200 generations. These two clones were chosen because they represented the best-adapted clones among six independently evolved populations. ES10-5 acquired new mutations in genes potentially involved in salt tolerance, in addition to the preexisting mutations and different mutations in the same genes as in ES9-11. Most basal abundance changes of metabolites and phospholipid fatty acids (PLFAs) were lower in ES10-5 than ES9-11, but an increase of glutamate and branched PLFA i17:1ω9c under high-salinity conditions was persistent. ES9-11 had decreased cell motility compared to the ancestor; in contrast, ES10-5 showed higher cell motility under both nonstress and high-salinity conditions. Both genotypes displayed better growth energy efficiencies than the ancestor under nonstress or high-salinity conditions. Consistently, ES10-5 did not display most of the basal transcriptional changes observed in ES9-11, but it showed increased expression of genes involved in glutamate biosynthesis, cation efflux, and energy metabolism under high salinity. These results demonstrated the role of glutamate as a key osmolyte and i17:1ω9c as the major PLFA for salt tolerance in D. vulgaris. The mechanistic changes in evolved genotypes suggested that growth energy efficiency might be a key factor for selection. IMPORTANCE High salinity (e.g., elevated NaCl) is a stressor that affects many organisms. Salt tolerance, a complex trait involving multiple cellular pathways, is attractive for experimental evolutionary studies. Desulfovibrio vulgaris Hildenborough is a model sulfate-reducing bacterium (SRB) that is important in biogeochemical cycling of sulfur, carbon, and nitrogen, potentially for bio-corrosion, and for bioremediation of toxic heavy metals and radionuclides. The coexistence of SRB and high salinity in natural habitats and heavy metal-contaminated field sites laid the foundation for the study of salt adaptation of D. vulgaris Hildenborough with experimental evolution. Here, we analyzed a clone that evolved under salt stress for 5,000 generations and compared it to a clone evolved under the same condition for 1,200 generations. The results indicated the key roles of glutamate for osmoprotection and of i17:1ω9c for increasing membrane fluidity during salt adaptation. The findings provide valuable insights about the salt adaptation mechanism changes during long-term experimental evolution.
Domaine de référence : Biocorrosion
Auteur Zhou Aifen, Lau Rebecca, Baran Richard, Ma Jincai, Netzer Frederick von, Shi Weiling, Gorman-Lewis Drew, Kempher Megan L., He Zhili, Qin Yujia, Shi Zhou, Zane Grant M., Wu Liyou, Bowen Benjamin P., Northen Trent R., Hillesland Kristina L., Stahl David A., Wall Judy D., Arkin Adam P., Zhou Jizhong
Année de parution : 2017.
Mots-clés : cell motility, Desulfovibrio vulgaris, energy efficiency, genomic mutations, organic solutes, PLFA, transcriptomics.
Type de document : Article de revue.
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Silane coatings for mitigation of microbiologically influenced corrosion of mild steel

Résumé : Abstract Mild steel continues to be the most extensively used construction material in several industries. However, steels suffer from corrosion in aqueous solutions. Coating is one of the common measures to circumvent corrosion. Silane coating is among the recent and promising measures to improve the corrosion resistance of metallic materials in corrosive environments. Silane coatings are becoming increasingly popular particularly over the traditional chromate conversion coatings that have harmful effects on human health and the environment and hence face increasingly regularity restrictions. This study has been conducted to evaluate the influence of silane treatments on corrosion resistance of mild steel in sodium chloride environment and the mitigation of microbial influenced corrosion (MIC) of mild steel due to sulphate reducing bacteria (SRB). The optimum conditions (viz; pHs of hydrolysis and condensation, hydrolysis time, dipping time and application method) of single/two step silane coatings of Bis-[triethoxysilyl]ethane (BTSE), bis-[trimethoxysilylpropyl]amine (bis-amino silane), 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (quaternary ammonium silane) and octadecyltrimethoxysilane (ODTMS) silanes have been investigated for improving corrosion resistance of mild steel in aggressive chloride solution (similar to sea water). The influence of silane coatings on corrosion performance of mild steel has been explained on the basis of electrochemical and analytical characterizations using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization test, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). Electrochemical measurements showed that the corrosion resistance of mild steel improved due to the BTSE silane coatings that were deposited at an optimum pH 4 of deposition. The longer the dipping time the better is the corrosion resistance of BTES-coated mild steel in the chloride solution. The time of hydrolysis of 3 h for octadecyltrimethoxysilane (ODTMS) in water alcohol solution at pH 4 was found to be optimum for producing the stable and fully hydrolysed silane. Thus, the silane film developed under this condition was found to provide considerable corrosion resistance up to 24 h in 0.6 M NaCl solution. The significant decrease in corrosion resistance with increase in time of pre-immersion in corrosive solution was attributed to the ingress of corrosive media to the metal surface. As seen from the electrochemical tests, two step ODTMS coating enhanced the inhibition action of mild steel against corrosion in NaCl solution. However; the two step ODTMS coating is still permeable. Similar to what has been reported for the long aliphatic silane films deposited on other metals and alloys, the ODTMS coating on mild steel is suggested to possess defects, such as interconnected pores. Although, quaternary ammonium silane coatings have been used to improve the antimicrobial activity of coated surfaces, the interaction of the positively-charged ammonium group with water causes degradation of silane film when exposed to corrosive environments. The present work addresses the effect of two step silane coatings containing different concentrations of quaternary ammonium silane on corrosion resistance of mild steel in 0.6 M NaCl solution. The two step silane coatings were formed by dipping the mild steel coupons in non-functional silane solution [bis[triethoxysilyl]ethane (BTSE)] followed by dipping either in quaternary ammonium silane alone or in a silane mixture composed of bis-functional and quaternary ammonium silanes. For the second alternative, different silane mixtures were prepared by mixing of bis-[trimethoxysilylpropyl]amine (bis-amino silane) with different concentrations of 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride in different mixing ratios (1:1, 3:1and 5:1 V/V). Based on electrochemical measurement results, the corrosion resistance improved as a result of coatings developed upon two step silane treatments of BTSE followed by the mixture of bis-amino and quaternary ammonium silane. But, the corrosion resistance decreased significantly (and was even lower than that uncoated mild steel) when the quaternary ammonium silane alone was used as the top coating for BTSE-coated mild steel. After determination of the optimum conditions of silane treatments to achieve the best corrosion resistance of mild steel in NaCl solution, the optimum conditions for silane coating to mitigate the microbial influenced corrosion of mild steel in the presence of sulphate reducing bacteria (SRB) have been investigated. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and cyclic polarization tests were used to evaluate the enhancement in corrosion resistance of mild steel pre-exposed to biotic (media inoculated with SRB) and abiotic environments. To characterize the deposits on mild steel surface before and after MIC process; FTIR analysis were used. The coupons were examined for their surface biofilms and corrosion features, using SEM/EDX technique. Generally, the silane-coated mild steel suffered less acceleration in corrosion in the presence of SRB, as seen from the corrosion potential, which moved less towards cathodic direction compared to that of uncoated specimens. Electrochemical investigations showed that the coating developed upon two step treatment of octadecyltrimethoxysilane had the least corrosion current density and the highest impedance among the investigated coatings. The least tendency to pitting was observed for the coating, developed upon two step silane treatments of BTSE, followed by the mixture of bis-amino and quaternary ammonium silanes in mixing ratios of 5:1 (V/V). BTSE treatment alone did not improve the corrosion resistance of mild steel in the presence of SRB.
Domaine de référence : Biocorrosion
Auteur Al-Saadi Saad Hamood Mohaissn
Année de parution : 2017.
Mots-clés : 1959.1/907490, 2013, Corrosion, Electrochemistry, ethesis-20131031-152027, Impedance spectroscopy, Microbial corrosion, Mild steel, monash:120328, Open access and full embargo, Silane coatings, thesis(doctorate).
Type de document : Document.
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Characterization of bacterial community and iron corrosion in drinking water distribution systems with O3-biological activated carbon treatment

Résumé : Bacterial community structure and iron corrosion were investigated for simulated drinking water distribution systems (DWDSs) composed of annular reactors incorporating three different treatments: ozone, biologically activated carbon and chlorination (O3-BAC-Cl2); ozone and chlorination (O3-Cl2); or chlorination alone (Cl2). The lowest corrosion rate and iron release, along with more Fe3O4 formation, occurred in DWDSs with O3-BAC-Cl2 compared to those without a BAC filter. It was verified that O3-BAC influenced the bacterial community greatly to promote the relative advantage of nitrate-reducing bacteria (NRB) in DWDSs. Moreover, the advantaged NRB induced active Fe(III) reduction coupled to Fe(II) oxidation, enhancing Fe3O4 formation and inhibiting corrosion. In addition, O3-BAC pretreatment could reduce high-molecular-weight fractions of dissolved organic carbon effectively to promote iron particle aggregation and inhibit further iron release. Our findings indicated that the O3-BAC treatment, besides removing organic pollutants in water, was also a good approach for controlling cast iron corrosion and iron release in DWDSs.
Domaine de référence : Biocorrosion
Auteur Xing Xueci, Wang Haibo, Hu Chun, Liu Lizhong
Année de parution : 2017.
Mots-clés : Bacterial community, Corrosion inhibition, Drinking water distribution systems (DWDSs), Iron release, Nitrate-reducing bacteria (NRB), O3-biological activated carbon (O3-BAC).
Type de document : Article de revue.
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Corrosion of mild steel at the seawater/sediments interface : Mechanisms and kinetics

Résumé : Corrosion product layers formed on mild steel coupons after 6 years of permanent immersion at shallow depth in marine sediments were characterized by X-ray diffraction and μ-Raman spectroscopy. They proved mainly composed of FeS which testifies for an intense sulfate-reducing bacteria activity. Other identified compounds were siderite FeCO3 and four varieties of green rust associated with local variations of composition of the environment. The corrosion rates determined by residual thickness measurements were higher on the lower half of the coupons (average 40μm/yr, local maximum 140μm/yr) and smaller on the upper half, suggesting that differential aeration effects took place.
Domaine de référence : Biocorrosion
Auteur Refait Ph., Grolleau A. -M., Jeannin M., François E., Sabot R.
Année de parution : 2017.
Mots-clés : A. Mild steel, B. Raman spectroscopy, B. X-ray diffraction, C. Microbiological corrosion, C. Rust.
Type de document : Article de revue.
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Experimental Study on the Influence of Sulfate Reducing Bacteria on the Metallic Corrosion Behavior under Disbonded Coating

Résumé : A rectangle disbonded coating simulation device was used to research the effect of sulfate reducing bacteria (SRB) on the metallic corrosion behavior under disbonded coating by the electrochemical method. The results showed that the metal self-corrosion potential at the same test point had little change in the initial experiment stage, whether the solution was without or with SRB. The potential amplitude in the solution with SRB was larger than that without SRB in the later corrosion period. The corrosion current density of the metal at the same test point increased gradually over time in the solution with or without SRB, and SRB could accelerate the corrosion of the metal in the disbonded crevice. The metal self-corrosion potential in the crevice had little change in the SRB solution environment after adding the fungicide, but the corrosion current density decreased significantly. That meant the growth and reproduction of SRB were inhibited after adding the fungicide, so the metal corrosion rate slowed down. Among the three kinds of solution environment, increasing the coating disbonded thickness could accelerate the corrosion of the metal in the crevice, and it was the largest in the solution with SRB.
Domaine de référence : Biocorrosion
Auteur Ding Qingmiao, Fang Liping, Cui Yanyu, Wang Yujun
Année de parution : 2017.
Type de document : Page Web.
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Pyrosequencing analysis of source water switch and sulfate-induced bacterial community transformation in simulated drinking water distribution pipes

Résumé : Inter-basin water transfer and source water switching will be increasingly launched due to significant population increase and the shortage of the local water resources in cities around the world. Source water switch may cause physiochemical and microbiological de-stabilization of pipe material, biofilms, and loose deposits in drinking water distribution system (DWDS). Great sulfate alteration during source water switch had been deemed as the main cause of a red water case that occurred in a northern China city. To ascertain the relationship between water quality changing and bacterial communities of biofilms in DWDS and possible bacteria risk in a red water case, water quality changing experiments in simulated DWDSs were conducted for approximately 2 years. Twenty-five corrosion scale samples and eight water samples collected from pipe harvest sites or during experimental periods were analyzed for their bacterial community composition by 454-pyrosequencing technology. Taxonomy results together with redundancy analysis (RDA) or canonical correspondence analysis (CCA) and hierarchical cluster analysis all indicated that bacterial community of samples with groundwater (GW) or surface water (SW) supply history and their variations under high sulfate water were rather different owing to different water source histories and the original pipe scale characteristics. Potential opportunistic pathogens: Burkholderia, Escherichia-Shigella, Mycobacterium, Serratia, Ralstonia, Novosphingobium, Flavobacterium, Sphingomonas, and Sphingopyxis were observed in scale or water samples.
Domaine de référence : Biocorrosion
Auteur Yang Fan, Shi Baoyou, Zhang Weiyu, Cui Jing, Guo Jianbo, Wang Dongsheng, Wu Nan, Liu Xinyuan
Année de parution : 2017.
Type de document : Article de revue.
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Corrosion Behavior of Cupronickel Alloy in Simulated Seawater in the Presence of Sulfate-Reducing Bacteria

Résumé : The corrosion behavior of cupronickel alloy immersed in the simulated seawater in or without the presence of sulfate-reducing bacteria (SRB) was studied. The results of scanning electronic microscopy and electrochemical impedance spectra reveal that corrosion of the sample immersed in the simulated seawater with SRB was more serious than that immersed in the simulated seawater without SRB. The atomic force microscopy images show that after immersion for 15 days, the surface roughness of the sample in the simulated seawater with SRB was higher than that of the sample in the simulated seawater without SRB. The analysis of confocal laser scanning microscopy indicates that the average depth of the pits on the surface of the sample in the simulated seawater with SRB was almost twice deeper than that of the sample in the simulated seawater without SRB.
Domaine de référence : Biocorrosion
Auteur Song Yanyan, Shi Hongwei, Wang Jun, Liu Fuchun, Han En-Hou, Ke Wei, Jie Ganxin, Wang Jun, Huang Haijun
Année de parution : 2017.
Type de document : Article de revue.
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Comparison of microbial communities across sections of a corroding sewer pipe and the effects of wastewater flooding

Résumé : This study investigated the variation in microbially induced concrete corrosion communities at different circumferential locations of a real sewer pipe and the effects of a wastewater flooding event on the community. Three distinct microbial community groups were found in different corrosion samples. The physico-chemical properties of the corrosion layers and the microbial communities were distinct for the cross-sectional positions within the pipe, ie ceiling, wall and tidal zones. The microbial communities detected from the same positions in the pipe were consistent over the length of the pipe, as well as being consistent between the replicate pipes. The dominating ceiling communities were members of the bacterial orders Rhodospirillales, Acidithiobacillales, Actinomycetales, Xanthomonadales and Acidobacteriales. The wall communities were composed of members of the Xanthomonadales, Hydrogenophilales, Chromatiales and Sphingobacteriales. The tidal zones were dominated by eight bacterial and one archaeal order, with the common physiological trait of anaerobic metabolism. Sewage flooding within the sewer system did not change the tidal and wall communities, although the corrosion communities in ceiling samples were notably different, becoming more similar to the wall and tidal samples. This suggests that sewage flooding has a significant impact on the corrosion community in sewers.
Domaine de référence : Biocorrosion
Auteur Cayford Barry I., Jiang Guangming, Keller Jurg, Tyson Gene, Bond Philip L.
Année de parution : 2017.
Mots-clés : Concrete, Corrosion, flooding, Hydrogen sulfide, Microbial community, Sewer, wastewater.
Type de document : Article de revue.
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Microbially Induced Corrosion in Firefighting Systems—Experience and Remedies

Résumé : Firefighting water systems are important safety systems in all industries, including nuclear power plants (NPPs). However, they are susceptible to microbially induced corrosion, which is a degradation mode needing special attention. Leakages were observed in a fire fighting system made from stainless steel at a nuclear power plant shortly after maintenance and modernization work, which included replacement of part of the old carbon steel pipelines with stainless steel pipelines, as well as exchange of some Type 304 stainless steel pipes with Type 316 pipes due to relining parts of the system. The failure analysis revealed sub-surface corrosion cavities with pinholes at the inner surface and finally penetrating the whole pipe wall thickness. It was concluded that the reason for the leaks was due to microbially induced corrosion, (MIC). The paper will present the results from failure analyses, explain the remedial actions taken at the power plant, and discuss the implication of these findings on new similar systems, including the importance of avoiding iron deposits and optimization of water quality.
Domaine de référence : Biocorrosion
Auteur Ehrnstén Ulla, Carpén Leena, Tompuri Kimmo
Année de parution : 2017.
Type de document : Chapitre de livre.
Source : Springer, Cham
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The effect of sulfate-reducing bacteria on hydrogen permeation of X80 steel under cathodic protection potential

Résumé : The pipelines buried underground are always influenced by sulfate-reducing bacteria (SRB) and cathodic protection (CP). The literature had recorded the fracture accidents of buried pipeline caused by SRB and cathodic potential. To investigate whether SRB can influence the hydrogen damage of pipeline steel under cathodic potential, the synergistic effect of SRB and cathodic potential on hydrogen permeation behavior of X80 steel was investigated by electrochemical tests and optical observation, by which both the growth cycle of microorganism and the applied potential are considered. The results showed that the hydrogen permeation current density of X80 steel in SRB-inoculated solution was three times higher than that without SRB. Serious hydrogen blistering on the surface of specimen was observed in the presence of SRB. The permeation current increases with the negative shifting of the applied cathodic potential in SRB-inoculated solution, which is attributed to the cathodic polarization and the metabolic activities of SRB. The research indicated that the hydrogen damage of pipeline is more likely occurred in the environments with SRB under a more negative cathodic CP potential.
Domaine de référence : Biocorrosion
Auteur Wang Dan, Xie Fei, Wu Ming, Sun Dongxu, Li Xue, Ju Jiyuan
Année de parution : 2017.
Mots-clés : Cathodic potential, Hydrogen permeation, Pipeline steel, sulfate-reducing bacteria.
Type de document : Article de revue.
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Effect of organic on chemical oxidation for biofouling control in pilot-scale seawater cooling towers

Résumé : Due to the scarcity of potable water in many regions of the world, the demand for seawater as an alternative evaporative cooling medium in cooling towers (CTs) has increased significantly in recent years. Seawater make-up in CTs is deemed the most feasible because of its unlimited supply in the coastal areas of Gulf and Red Sea. However, the seawater CTs have higher challenges greatly mitigating their performances because it is an open system where biofouling and bio-corrosion occurring within the fillers and piping of recirculation systems. Their pilot-scale CTs were constructed to assess the performance of three types of oxidizing biocides or oxidants, namely chlorine, chlorine dioxide (ClO2) and ozone, for biofouling control. The test results showed that the addition of organic (5mg/L of methanol (MeOH)) increased the bacterial growth in CT basin. All oxidants were effective in keeping the microbial growth to the minimum. Oxidation increased the oxidation-reduction potential (ORP) level from 270 to 600mV. Total residual oxidant (TRO) was increased with oxidation but it was slightly increased with organic addition. Other parameters including pH, dissolved oxygen (DO), conductivity levels were not changed. However, higher formation of disinfection by-products (DBPs) was detected with chlorination and ozonation. This indicates the organic level should be limited in the oxidation for biofouling control in seawater CTs.
Domaine de référence : Biocorrosion
Auteur Al-Bloushi Mohammed, Saththasivam Jayaprakash, Jeong Sanghyun, Amy Gary L., Leiknes TorOve
Année de parution : 2017.
Type de document : Article de revue.
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Dispersal and Inhibitory Roles of Mannose, 2-Deoxy-D-Glucose, and N-Acetylgalactosaminidase on the Biofilm of Desulfovibrio vulgaris

Résumé : Biofilms of sulfate-reducing bacteria (SRB) are often the major cause of microbiologically influenced corrosion. The representative SRB Desulfovibrio vulgaris has previously been shown to have a biofilm that consists primarily of protein. In this study, by utilizing lectin staining, we identified that the biofilm of D. vulgaris also consists of the matrix components mannose, fucose, and N-acetylgalactosamine (GalNAc), with mannose predominating. Based on these results, we found that the addition of mannose and the non-metabolizable mannose analog 2-deoxy-D-glucose inhibits the biofilm formation of D. vulgaris as well as that of D. desulfuricans; both compounds also dispersed the SRB biofilms. In addition, the enzyme N-acetylgalactosaminidase, which degrades GalNAc, was effective in dispersing D. vulgaris biofilms. Therefore, by determining composition of the SRB biofilm, effective biofilm control methods may be devised. This article is protected by copyright. All rights reserved.
Domaine de référence : Biocorrosion
Auteur Poosarla Venkata G., Wood Thammajun L., Zhu Lei, Miller Daniel S., Yin Bei, Wood Thomas K.
Année de parution : 2017.
Type de document : Article de revue.
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Microstructure, mechanical properties and biocorrosion behavior of dissimilar welds of AISI 904L and UNS S32750

Résumé : This article addresses the joining of 5 mm thick plates of marine grade, super-austenitic (AISI 904L) and super-duplex stainless steels (UNS S32750) by pulsed current gas tungsten arc welding using duplex and austenitic stainless steel fillers. Microstructure studies revealed the segregation of Mo-rich phases in the fusion zone while employing ERNiCrMo-10. Grain coarsening was observed at the heat affected zone (HAZ) of super-duplex stainless steel in both the cases. The study attested that all the tensile failures experienced in the parent metal, AISI 904L for both the weldments. Charpy V-notch impact studies demonstrated that the weldments employing ER2553 were experienced better impact toughness than ERNiCrMo-10 weldments. Further potentiodynamic polarization test in 3.5% NaCl environment was conducted on the coupons of the weldments. The coupons of the weldments were then tested for accelerated corrosion in salt fog chamber for 300 h in 3.5% NaCl environment. This accelerated corrosion test concludes that the parent metal AISI 904L experienced better corrosion resistance than the fusion zones. The investigation also deals with biocorrosion studies of the dissimilar welds of super-austenitic and super-duplex stainless steels. Microbial consortium comprising of six bacterial isolates of which four were Pseudomonas strains P. aeruginosa strain MB1, P. aeruginosa strain MB2, P. fluorescens and P. flavescens, two belonged to Bacillus strains, B. subtilis and B. cereus, for the first time. The bacterial isolates were inoculated in the medium with the presence of the metal coupons. The results were obtained after 15 and 30 days interval and compared with the control to determine the rate of biocorrosion which confirms that there is an accelerated deterioration of the metal coupons by the microbial strains.
Domaine de référence : Biocorrosion
Auteur K. Devendranath Ramkumar, Dagur Akash Harendra, Kartha Ashwin Anil, Subodh Moharil Atharva, C. Vishnu, D. Arun, Giridharan Vijay Kumar M., Abraham Winston Sunny, Chatterjee Ankita, Abraham Jayanthi, Abraham Johann
Année de parution : 2017.
Mots-clés : Microbial- induced corrosion, Microstructure, Pulsed current gas tungsten arc welding, Super-austenitic stainless steel, Super-duplex stainless steel.
Type de document : Article de revue.
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Study of poly(3,4-ethylendioxythiphene) as a coating for mitigation of biocorrosion of AISI 304 stainless steel in natural seawater

Résumé : In this work the poly(3,4-ethylenedioxythiophene) (PEDOT) was evaluated to mitigate biocorrosion of conventional stainless steel (SS), grade AISI 304, under exposure to natural seawater. PEDOT was obtained electrochemically onto the steel and coated coupons were immersed in flow-through exposure rig fed with fresh seawater. Corrosion performance of the coupons SS and SS/PEDOT was characterised using electrochemical analysis of open circuit potentials and polarization curves measured on samples retrieved after 7, 35 and 210 days of exposure. For the same retrieval times, the evolution of the biofilm was inspected by scanning electron microscopy (SEM), and microbiological analysis by denaturing gradient gel electrophoresis (DGGE) and fluorescence microscopy. Results indicate that PEDOT delays the growth of the biofilm on the modified steel surface by at least 35 days, producing a less variable bacterial community over time as compared to the uncoated steel surface. In addition, PEDOT retains electrochemical stability throughout the exposure, which is mainly attributed to the intrinsic properties of the conducting polymer.
Domaine de référence : Biocorrosion
Auteur Aguirre Javiera, Daille Leslie, Fischer Diego A., Galarce Carlos, Pizarro Gonzalo, Vargas Ignacio, Walczak Magdalena, de la Iglesia Rodrigo, Armijo Francisco
Année de parution : 2017.
Mots-clés : Antifouling, Coating, Conducting polymer, Marine corrosion, Poly(3,4-ethylenedioxythiophene), Stainless Steel.
Type de document : Article de revue.
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Mechanism of microbiologically influenced corrosion of X52 pipeline steel in a wet soil containing sulfate-reduced bacteria

Résumé : In this work, corrosion of an X52 pipeline steel was investigated in a field-collected soil containing sulfate-reducing bacteria (SRB) by weight-loss testing, bio-testing, electrochemical measurements and surface analysis techniques. The SRB can grow well in the soil and attach to the steel surface, leading to microbiologically influenced corrosion (MIC) of the steel. The SRB are able to accelerate corrosion of the steel remarkably. Compared to the corrosion rate of 0.0473mm/y in SRB-absent soil, the corrosion rate of the steel is up to 0.282mm/y when SRB are contained in the soil. An increase of the water content in the soil favors the growth of SRB, increasing the thickness of the biofilm formed on the steel surface and accelerating the steel MIC. At individual water contents, the presence of CO2 in the soil accelerates the steel MIC induced by SRB, which is associated with the increasing amount of SRB cells in CO2-containing soil. The SRB also result in localized corrosion of the steel. This is associated with the unique soil corrosion environment, where the sessile SRB cells and corrosion products do not move freely. The porous structure of the surface film contributes to the initiation of localized corrosion.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Frank Cheng Y.
Année de parution : 2017.
Mots-clés : microbiologically influenced corrosion, Pipelines, Soil, sulfate-reducing bacteria, Water content.
Type de document : Article de revue.
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Effect of Adsorbed Organic Thin Films on Electrochemical Interaction Mechanisms of Metal Reducing Bacteria with Steel Surfaces

Domaine de référence : Biocorrosion
Auteur Wurzler Nina, Ozcan Ozlem
Année de parution : 2017.
Type de document : Article de revue.
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The decisive role of acidophilic bacteria in concrete sewer networks : A new model for fast progressing microbial concrete corrosion

Résumé : This study introduces a novel approach intertwining analytics of spatial microbial distribution with chemical, mineralogical and (micro)structural related aspects in corroded concrete sewer environments. Samples containing up to 4 cm thick corrosion layers were collected from concrete manholes and analysed using hydro-geochemical, microbiological, biochemical and mineralogical methods. Opposed to the current opinion DNA and RNA indicating microbial activity were found throughout the entire deterioration layer down to the corrosion front. Elemental distributions of corresponding areas revealed a dynamic pH- and diffusion-controlled system in which a distinct succession of elemental accumulations was unequivocally correlated with responding pH levels, associated dissolution and precipitation of solids, as well as with the spatially resolved presence of microbes. Microbial activity further coincided with massive iron deposition zones, within the inner anoxic to anaerobic corrosion layers. As a possible microbial catalyst for iron oxidation and in-situ acid production in this zone, we propose Acidithiobacillus ferrooxidans which were isolated from the deteriorated concrete. Based on the data we propose a new model in which biogenic induced in-situ acid production is a decisive factor, steering high concrete corrosion rates of &gt; 1 cm yr− 1.
Domaine de référence : Biocorrosion
Auteur Grengg C., Mittermayr F., Koraimann G., Konrad F., Szabó M., Demeny A., Dietzel M.
Année de parution : 2017.
Mots-clés : Acid corrosion, Concrete, EMPA, Micro XRD, Microbiological corrosion, Sulphuric acid.
Type de document : Article de revue.
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Laboratory testing of enhanced biocide mitigation of an oilfield biofilm and its microbiologically influenced corrosion of carbon steel in the presence of oilfield chemicals

Résumé : Microbiologically influenced corrosion (MIC) is prevalent in the oil and gas industry. Problematic biofilms cause MIC and reservoir souring. A high biocide concentration is usually required to mitigate biofilms compared with planktonic cells. This causes economic and environmental concerns. A biocide enhancer can make a biocide more effective using the same or lower biocide dosage. In this work, an equimolar mixture of 100 ppm (w/w) of four D-amino acids (D-methionine, D-tyrosine, D-tryptophan, and D-leucine) labeled as D-mix enhanced 100 ppm tetrakis (hydroxymethyl) phosphonium sulfate (THPS) against a field biofilm consortium on C1018 carbon steel coupons. In order to test chemical compatibilities, D-amino acids were added together with THPS and enhanced oil recovery chemicals (a polymer, a surfactant, a corrosion inhibitor, and a scale inhibitor) to treat the mature biofilm consortium. After a 7-day biofilm removal test in 125 ml anaerobic vials, the cocktail of 100 ppm THPS +100 ppm D-mix achieved extra logs of reduction in sessile cell counts compared with the 100 ppm THPS alone treatment. The combination also achieved lower weight loss and smaller maximum pit depths. Electrochemical tests corroborated the weight loss and pitting data.
Domaine de référence : Biocorrosion
Auteur Jia Ru, Yang Dongqing, Abd Rahman Hasrizal Bin, Gu Tingyue
Année de parution : 2017.
Mots-clés : Biocide, Biocide enhancer, Biofilm, D-amino acid, Enhanced oil recovery, microbiologically influenced corrosion.
Type de document : Article de revue.
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Corrosion of carbon steel in the presence of oilfield deposit and thiosulphate-reducing bacteria in CO2 environment

Résumé : The effect of thiosulphate reducing bacteria (TRB) on the corrosion of carbon steel covered by a complex oilfield deposit has been assessed in CO2-containing seawater at 55° C. TRB were found to significantly accelerate localized corrosion at deposited steels. This effect of TRB on under-deposit corrosion (UDC) was related to metabolic production of corrosive compounds, such as sulphide and acidic species, through biodegradation of organic matter and thiosulfate reduction in the deposit. TRB were also found to promote accumulation of hydrocarbons and metals in the deposit. Results highlight that microbial-deposit interactions are a noteworthy process in corrosion of oilfield facilities.
Domaine de référence : Biocorrosion
Auteur Machuca Laura L., Lepkova Katerina, Petroski Adrian
Année de parution : 2017.
Mots-clés : A. Carbon steel, B. Cyclic voltammetry, B. Polarization, B. SEM, C. Microbiological corrosion.
Type de document : Article de revue.
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Effects of heat shocks on biofilm formation and the influence on corrosion and scaling in a geothermal plant in the North German Basin

Résumé : At geothermal plants, process failures often occur due to corrosion and scaling processes. Especially after heat extraction, sulfate reducing bacteria contribute to corrosion processes by producing reduced sulfur compounds. In biofilms containing scales such as iron sulfides, corrosion processes are enhanced. In a mobile bypass system located at the geothermal plant in Neubrandenburg (North German Basin), the influence of biofilm formation on corrosion and scaling was investigated. Short-term heat shocks were successfully tested in the bypass system in order to reduce biofilm formation and thus to diminish corrosion and scaling processes.
Domaine de référence : Biocorrosion
Auteur Kleyböcker Anne, Lienen Tobias, Kasina Monika, Westphal Anke, Teitz Sebastian, Eichinger Florian, Seibt Andrea, Wolfgramm Markus, Würdemann Hilke
Année de parution : 2017.
Mots-clés : Biofilm, microbial influenced corrosion (MIC), Scaling, sulfate reducing bacteria (SRB).
Type de document : Article de revue.
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Effect of Heat Treatment and Types of Bacteria on Corrosion Resistance At Steel Materials (API 5L and ASTM A53) in the Marine Environment

Résumé : Corrosion is the result of damage to material degradation through a chemical or electrochemical reaction spontaneously and causes a decrease in the quality of the material. One of the causes of corrosion is the presence of bacteria on the material. The danger posed by corrosion is fatality, especially on offshore platforms, namely cessation of production at offshore rigs. This study is an experiment using material carbon steel API 5L Grade B and ASTM A53 commonly used as a base for the manufacture of subsea pipelines. Material to be heat-treated before immersion for corrosion test in artificial seawater (salinity 35‰), which have been added with bacteria and without bacteria. The method used in measuring the rate of corrosion steel data is the weight loss. The highest corrosion rate of the original material ASTM A53 and API 5L with the addition of T. ferrooxidans bacteria are, respectively, 3.63 mpy and 3.50 mpy. While the lowest corrosion rate of ASTM A53 and API 5L both with heat treatment but without adding bacteria are 2.33 mpy and 2.01 mpy. This indicates that the steel API 5L have high levels of corrosion resistance, better than ASTM A53 in the marine environment with bacteria or without bacteria.
Domaine de référence : Biocorrosion
Auteur Pratikno Herman, Titah Harmin S., Sastradimaja Febrian R.
Année de parution : 2017.
Mots-clés : API 5L Grade B, ASTM A53, Bacteria, bio-corrosion, Corrosion, heat treatment.
Type de document : Article de revue.
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ANTIBIOCORROSIVE EPOXY-BASED COATINGS WITH LOW FRICTION AND HIGH SCRATCH RESISTANCE

Résumé : We have created inorganic-organic hybrid composites and antibiocorrosive coatings based on an epoxy modified with silicon-containing polyepoxies and bioactive coordination compounds. The scratch resistance was determined using a conical diamond indenter with linearly increased load. Repetitive scratching along the same groove (sliding wear determination) was also performed. Whether in single or in repetitive scratching, for most hybrids the residual depth is shallower than for the pure epoxy. Dynamic friction was determined on a pin-on-disk tribometer using steel pins. Lower friction is accompanied by higher scratch resistance. Surface morphology seen in scanning electron microscopy (SEM) shows that increasing modifier content causes more ductile behavior with less crack nucleation; no debris formation is observed. The composites were also characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Isothermal aging and water absorption ability (WH2O) of the hybrids were determined. The hybrids are optically transparent, visually homogeneous, with smooth surfaces.
Domaine de référence : Biocorrosion
Auteur Barbakadze Khatuna, Brostow Witold, Datashvili Tea, Hnatchuk Nathalie, Lekishvili Nodar
Année de parution : 2017.
Mots-clés : polymer aging, polymer friction, polymer scratch resistance, water absorption.
Type de document : Article de revue.
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Microbial biotechnology approaches to mitigating the deterioration of construction and heritage materials

Résumé : Microorganisms are the main engines of elemental cycling in this planet and therefore have a profound impact on both organic and mineral substrates. As such, past and present human-made structures and cultural heritage can be negatively affected by microbial activity. Processes such as bioweathering (rocks and minerals), biodeterioration (organic substrates) or biocorrosion (metals) participate to the degradation or structural damage of construction and heritage materials. This structural damage can cause major economic losses (e.g. replacement of cast-iron pipes in water distribution networks), and in the case of heritage materials, the entire loss of invaluable objects or monuments. Even though one can regard the influence of microbial activity on construction and heritage materials as negative, remarkably, the same metabolic pathways involved in degradation can be exploited to increase the stability of these materials.
Domaine de référence : Biocorrosion
Auteur Junier Pilar, Joseph Edith
Année de parution : 2017.
Type de document : Article de revue.
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Bio-corrosion on Aluminium 6063 by Escherichia coli in Marine Environment

Résumé : Biological corrosion is caused by presence of microbes in environment. Escherichia coli causes serious biofouling in various environments and its pronounced influence on marine biofouling that causing serious problems such as accelerated corrosion. E. coli shares similar properties with most marine bacteria and it was extensively studied for marine environment. The aims of this research was to determine the corrosion rate on Aluminium 6063 by E. coli in deep seawater (salinity of 33‰), medium seawater (salinity of 35‰), shallow seawater (salinity of 37‰). Based on results, bio-corrosion rate on Al 6063 were higher than control. The bio-corrosion rate Al 6063 at day 28 in salinity of 37‰ was 1.1233 mm/year, meanwhile the corrosion rate for control was 0.7225 mm/year. Visual observation showed that corrosion occured on surface on specimen. Macrostructure observation showed that white spots occured on surface of specimen with E. coli was higher than specimen in control (without E. coli, only saline water) It was indicating that presence of E. coli caused increasing of corrosion rate on Al 6063.
Domaine de référence : Biocorrosion
Auteur Pratikno Herman, Sulistiyaning Titah Harmin
Année de parution : 2017.
Type de document : Article de revue.
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Effect of sulphate-reducing bacteria on the microbiologically influenced corrosion of ten different metals using constant test conditions

Résumé : Testing conditions have been shown to influence the outcomes of microbiologically influenced corrosion (MIC) studies. Despite this there are only limited reports comparing the performance of different metal types in MIC studies using exactly the same test conditions. This makes it difficult to predict the relative performance of different materials in applications in which MIC may occur. In the present work, the microbiologically influenced corrosion of a range of ferrous and non-ferrous alloys have been studied under identical test conditions. Metal coupons were exposed to a relatively common MIC test arrangement consisting of the sulphate-reducing bacterium, Desulfovibrio desulfuricans, in modified Baar's medium for a period of 90 days under anaerobic conditions. The results showed accelerated corrosion of carbon steel and copper-nickel alloys in the biotic test condition (i.e. with bacteria) compared to abiotic test conditions. No evidence of corrosion, however, was observed on any of the stainless steels, Inconel or titanium alloys in either of the abiotic or biotic test conditions studied.
Domaine de référence : Biocorrosion
Auteur Javed M. A., Neil W. C., McAdam G., Wade S. A.
Année de parution : 2017.
Mots-clés : ALLOYS, Carbon steel, microbiologically influenced corrosion, Stainless Steel, sulphate-reducing bacteria.
Type de document : Article de revue.
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Comparison of different electrochemical techniques for continuous monitoring of the microbiologically influenced corrosion of 2205 duplex stainless steel by marine Pseudomonas aeruginosa biofilm

Résumé : Different electrochemical techniques and surface analysis methods were used to continuously monitor the corrosion of 2205 duplex stainless steel (DSS) in P. aeruginosa inoculated medium. It was found that linear polarization resistance and electrochemical impedance spectroscopy, significantly inhibited the attachment and growth of the biofilm, due to an internal electric field, leading to lower corrosion rates. In comparison, electrochemical noise as a passive electrochemical measurement technique did not adversely impact the biofilm, and the corrosion rate and the largest pit depth distribution from electrochemical noise were the closest to those from weight-loss data, making it a more suitable technique to monitor MIC by fragile biofilms.
Domaine de référence : Biocorrosion
Auteur Zhao Yang, Zhou Enzhe, Liu Yuzhi, Liao Shangju, Li Zhong, Xu Dake, Zhang Tao, Gu Tingyue
Année de parution : 2017.
Mots-clés : A. Stainless steel, B. EIS, B. Polarization, C. Microbiological corrosion.
Type de document : Article de revue.
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Biocide-mediated corrosion of coiled tubing

Résumé : Coiled tubing corrosion was investigated for 16 field water samples (S5 to S20) from a Canadian shale gas field. Weight loss corrosion rates of carbon steel beads incubated with these field water samples averaged 0.2 mm/yr, but injection water sample S19 had 1.25±0.07 mm/yr. S19 had a most probable number of zero acid-producing bacteria and incubation of S19 with carbon steel beads or coupons did not lead to big changes in microbial community composition. In contrast other field water samples had most probable numbers of APB of 102/mL to 107/mL and incubation of these field water samples with carbon steel beads or coupons often gave large changes in microbial community composition. HPLC analysis indicated that all field water samples had elevated concentrations of bromide (average 1.6 mM), which may be derived from bronopol, which was used as a biocide. S19 had the highest bromide concentration (4.2 mM) and was the only water sample with a high concentration of active bronopol (13.8 mM, 2760 ppm). Corrosion rates increased linearly with bronopol concentration, as determined by weight loss of carbon steel beads, for experiments with S19, with filtered S19 and with bronopol dissolved in defined medium. This indicated that the high corrosion rate found for S19 was due to its high bronopol concentration. The corrosion rate of coiled tubing coupons also increased linearly with bronopol concentration as determined by electrochemical methods. Profilometry measurements also showed formation of multiple pits on the surface of coiled tubing coupon with an average pit depth of 60 μm after 1 week of incubation with 1 mM bronopol. At the recommended dosage of 100 ppm the corrosiveness of bronopol towards carbon steel beads was modest (0.011 mm/yr). Higher concentrations, resulting if biocide is added repeatedly as commonly done in shale gas operations, are more corrosive and should be avoided. Overdosing may be avoided by assaying the presence of residual biocide by HPLC, rather than by assaying the presence of residual surviving bacteria.
Domaine de référence : Biocorrosion
Auteur Sharma Mohita, An Dongshan, Liu Tao, Pinnock Tijan, Cheng Frank, Voordouw Gerrit
Année de parution : 2017.
Type de document : Article de revue.
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Setting an agenda for biofouling research for the marine renewable energy industry

Résumé : Extensive marine growth on man-made structures in the ocean is commonplace, yet there has been limited discussion about the potential implications of marine growth for the wave and tidal energy industry. In response, the Environmental Interactions of Marine Renewables (EIMR) Biofouling Expert Workshop was convened. Discussions involved participants from the marine renewable energy (MRE) industry, anti-fouling industry, academic institutions and regulatory bodies. The workshop aimed to consider both the benefits and negative effects of biofouling from engineering and ecological perspectives. In order to form an agenda for future research in the area of biofouling and the marine renewable energy industry, 119 topics were generated, categorised and prioritised. Identified areas for future focus fell within four overarching categories: operation and maintenance; structured design and engineering; ecology; and knowledge exchange. It is clear that understanding and minimising biofouling impacts on MRE infrastructure will be vital to the successful development of a reliable and cost effective MRE industry.
Domaine de référence : EMR , Biocorrosion
Auteur Loxton J, Macleod AK, Nall CR, McCollin T, Machado I, Simas T, Vance T, Kenny C, Want A, Miller R
Année de parution : 2017.
Mots-clés : Biofouling, Marine growth, Renewable energy, tidal, wave.
Type de document : Article de revue.
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Induction of pitting corrosion on stainless steel (grades 304 and 316) used in dairy industry by biofilms of common sporeformers

Résumé : This study hypothesised that there may be induction of pitting corrosion or microbially-induced corrosion on stainless steel (SS) dairy-processing surfaces by biofilms of common milk sporeformers such as Bacillus sporothermodurans and Geobacillus stearothermophilus. Scanning electron microscopy (SEM) and micrographs generated from energy-dispersive spectroscopy were used to observe pitting corrosion and to find the elemental composition and distribution on the control and pitted surfaces. From SEM images and energy-dispersive spectroscopy micrographs, it was observed that pitting corrosion on SS could be induced by biofilms of both B. sporothermodurans and G. stearothermophilus.
Domaine de référence : Biocorrosion
Auteur Gupta Somil, Anand Sanjeev
Année de parution : 2017.
Mots-clés : Biofilm, Microbially-induced corrosion, Pitting, Sporeformer, Stainless Steel.
Type de document : Article de revue.
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Superdurable Coating Fabricated from a Double-Sided Tape with Long Term “Zero” Bacterial Adhesion

Résumé : There is no coating technology currently available to prevent the notorious biofilm formation issue. Here, a potential solution to fully address this tough issue is reported by developing a super-antifouling coating. The use of zwitterionic hydrogel (a double-sided tape) and commercial superglue is combined and a durable and ultrarobust antifouling zwitterionic (DURA-Z) coating is created that can be easily and universally applied on common substrates. Commercial superglue mostly for binding hydrophobic materials is used to strongly immobilize the superhydrophilic DURA-Z coating through interpenetration. DURA-Z coating effectively solves several key challenges preventing the current antifouling coatings from practical use, including difficult fabrication, low efficacy, poor toughness, and durability. The fabricated DURA-Z coating retains antifouling property after 90 d of immersion in water, 50 d of buffer shearing, and 30 d of water flushing, and after repeated knife scratch and sandpaper abrasion under 570 kPa. The DURA-Z coating achieves a rarely reported long-term biofilm resistance to both Gram-positive and Gram-negative bacteria and fungi: it remains almost “zero” microbe adhesion after continuously challenged by more than 109 cells mL−1 culture medium for 30 d.
Domaine de référence : Biocorrosion
Auteur Wang Wei, Lu Yang, Zhu Hui, Cao Zhiqiang
Année de parution : 2017.
Mots-clés : Antifouling, biofilm resistance, durability, zwitterions.
Type de document : Article de revue.
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Microbial community structures of an offshore and near-shore oil production facilities after biocide treatment and the potential to induce souring and corrosion

Résumé : Microbial communities of six samples from Escravos and Meren oil production facility in Nigeria were examined after biocide treatment using cultural and molecular approaches. Sulfate reducing bacteria (SRB) count and activity were the highest in skimmer pit samples (1N1) which was affiliated with Euryarchchaeota (44%) and Proteobacteria (39%). Treatment of Meren injection water (1N2) with biocides significantly reduced SRB population (102 cell/ml). Sample 1N3 (produced water discharge area) and 1N5 (treated produced water) were dominated by 70.79 and 52% Euryarchaeota, respectively. 1N4 (partially treated produced water) was dominated by Euryarchaeota (51.78%) and Proteobacteria (38%), while 1N6 (produced oil) was dominated by Proteobacteria (28%) and Euryarchaeota (62.6%). Metabolic activities in 1N1, 1N4 and 1N5 were dominated by sulfate reduction and methanogenesis; however, that of 1N2 was dominated only by sulfate reduction, while 1N3 and 1N6 were dominated by methanogenesis. Anaerobic incubation of 1N1 samples gave relatively higher corrosion rates (0.065 mm/year) while 1N2, 1N3 and 1N5 gave moderate corrosion rates (0.018 to 0.037 mm/year). This investigation in a Nigerian oil facility have substantially expanded our knowledge on the extent of microbial diversity in these fields after routine biocide treatment and have also shown the abundance and complexity of microbial communities in these fields that have potential to initiate souring and corrosion despite regular biocide treatment. Key words: Sulfate reduction, methanogenesis, corrosion, souring, microbial diversity
Domaine de référence : Biocorrosion
Auteur Chuma C. Okoro, Oluseye A. Ekun, Michael I. Nwume
Année de parution : 2017.
Type de document : Article de revue.
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Corrosion behaviour of 2205 duplex stainless steel in pure cultures of sulphate reducing bacteria : SEM studies, electrochemical characterisation and biochemical analyses

Résumé : The paper presents the results on biofilm formation induced by pure Desulfovibrio desulfuricans strains and its effect on corrosion behaviour of 2205 duplex stainless steel (DSS). Biofilm formation and damage process stimulated by D. desulfuricans strains are analysed with reference to their metabolic activity and to the surface characterisation of structure and configuration of the biofilm. Electrochemical techniques are applied to monitor bacterial attachment to the steel surface and to determine the influence of bacteria on the passivity and corrosion resistance of 2205 DSS. The obtained results prove that 2205 DSS is rapidly colonised by D. desulfuricans and that the biofilms formed affect its corrosion resistance. Bacterial activity leads to the more noble corrosion potential values and to the increased current densities on the potentiodynamic polarisation curves. SEM observations reveal micropits as well as signs of crevice attack on the steel surface.
Domaine de référence : Biocorrosion
Auteur Dec W., Jaworska-Kik M., Simka W., Michalska J.
Année de parution : 2017.
Mots-clés : Biofilm, duplex stainless steel, microbiologically influenced corrosion, sulphate-reducing bacteria.
Type de document : Article de revue.
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Plus de références Biocorrosion


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Quorum quenching activity of indigenous quorum quenching bacteria and its potential application in mitigation of membrane biofouling

Résumé : BACKGROUND Quorum sensing (QS) could regulate gene expression so as to mediate some bacterial behaviors such as the production of extracellular polymeric substances (EPS) and biofilm formation. In this study, a quorum quenching (QQ) bacterium, was isolated from an indigenous lab-scale MBR and encapsulated in a dumpling-shaped microbial bag for biofouling control. RESULTS This QQ bacteria has a higher genetic homology with Acinetobacter bereziniae strain. The effect of time and temperature on the QQ activity of microbial bag was tested by degrading N-acyl homoserine lactone (AHL). The results showed the degradation of C8-HSL (N-Octanoyl-DL-homoserine lactone) and C6-HSL (N-Hexanoyl-L-homoserine lactone) could reach equilibrium within 2 h. In addition, the relatively suitable temperature for AHL degradation was 20°C, at which degradation rate of C6-HSL and C8-HSL by microbial bag was 88% and 69%, respectively. The antifouling efficiency of microbial bag was investigated by a constant pressure filtration system. With the microbial bag added, the decrease of permeability was obviously improved. After 14 d, the permeability with QQ decreased to 18% while the control experiment exhibited almost no permeability. CONCLUSION The excellent AHL degradation rate and the filtration test showed that this QQ bacteria has an excellent antifouling potential in membrane filtration systems.
Domaine de référence : Antifouling
Auteur Gu Yanling, Huang Jinhui, Zeng Guangming, Shi Yahui, Hu Yi, Tang Bi, Zhou Jianxin, Xu Weihua, Shi Lixiu
Année de parution : 2017.
Mots-clés : Antifouling, Biofilm, MBR, Quorum Quenching, Quorum Sensing.
Type de document : Article de revue.
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Low voltage electric potential as a driving force to hinder biofouling in self-supporting carbon nanotube membranes

Résumé : This study aimed at evaluating the contribution of low voltage electric field, both alternating (AC) and direct (DC) currents, on the prevention of bacterial attachment and cell inactivation to highly electrically conductive self-supporting carbon nanotubes (CNT) membranes at conditions which encourage biofilm formation. A mutant strain of Pseudomonas putida S12 was used a model bacterium and either capacitive or resistive electrical circuits and two flow regimes, flow-through and cross-flow filtration, were studied. Major emphasis was placed on AC due to its ability of repulsing and inactivating bacteria. AC voltage at 1.5 V, 1 kHz frequency and wave pulse above offset (+0.45) with 100Ω external resistance on the ground side prevented almost completely attachment of bacteria (>98.5%) with concomitant high inactivation (95.3 ± 2.5%) in flow-through regime. AC resulted more effective than DC, both in terms of biofouling reduction compared to cathodic DC and in terms of cell inactivation compared to anodic DC. Although similar trends were observed, a net reduced extent of prevention of bacterial attachment and inactivation was observed in filtration as compared to flow-through regime, which is mainly attributed to the permeate drag force, also supported by theoretical calculations in DC in capacitive mode. Electrochemical impedance spectroscopy analysis suggests a pure resistor behavior in resistance mode compared to involvement of redox reactions in capacitance mode, as source for bacteria detachment and inactivation. Although further optimization is required, electrically polarized CNT membranes offer a viable antibiofouling strategy to hinder biofouling and simplify membrane care during filtration.
Domaine de référence : Antifouling
Auteur Thamaraiselvan Chidambaram, Ronen Avner, Lerman Sofia, Balaish Moran, Ein-Eli Yair, Dosoretz Carlos G.
Année de parution : 2018.
Mots-clés : Alternating current, Bacterial attachment, Biofouling, Cell inactivation, Self-supported CNT membrane.
Type de document : Article de revue.
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A state-of-the-art review on passivation and biofouling of Ti and its alloys in marine environments

Résumé : High strength-to-weight ratio, commendable biocompatibility and excellent corrosion resistance make Ti alloys widely applicable in aerospace, medical and marine industries. However, these alloys suffer from serious biofouling, and may become vulnerable to corrosion attack under some extreme marine conditions. The passivating and biofouling performance of Ti alloys can be attributed to their compact, stable and protective films. This paper comprehensively reviews the passivating and biofouling behavior, as well as their mechanisms, for typical Ti alloys in various marine environments. This review aims to help extend applications of Ti alloys in extremely harsh marine conditions.
Domaine de référence : Antifouling
Auteur Yan Shaokun, Song Guang-Ling, Li Zhengxian, Wang Haonan, Zheng Dajiang, Cao Fuyong, Horynova Miroslava, Dargusch Matthew S., Zhou Lian
Année de parution : 2017.
Mots-clés : Biofouling, Passivity, Ti alloy.
Type de document : Article de revue.
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Macrofouling induced localized corrosion of stainless steel in Singapore seawater

Résumé : Biofouling induced corrosion of stainless steels grades UNS S31603 and UNS S31254 was investigated at three sites off Singapore for 30months. No corrosion was observed on grade UNS S31254, while the propensity for corrosion by shellfish of UNS S31603 is ranked as oyster>>barnacles>>green mussels. Oysters caused extensive localised corrosion, penetrating 2mm thick plates with 12months with tracks of corrosion several centimetres long. Shallow crevice corrosion was observed under dead barnacles, with an explanation presented for why corrosion is more severe under dead barnacles than live ones. Green mussels did not cause any corrosion.
Domaine de référence : Antifouling
Auteur Blackwood Daniel J., Lim Chin Sing, Teo Serena L. M., Hu Xiaoping, Pang Jianjun
Année de parution : 2017.
Mots-clés : A. Stainless steel, B. Weight loss, C. Crevice corrosion, C. Microbiological corrosion.
Type de document : Article de revue.
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Ennoblement, corrosion, and biofouling in brackish seawater : Comparison between six stainless steel grades

Résumé : In this work, six common stainless steel grades were compared with respect to ennoblement characteristics, corrosion performance and tendency to biofouling in brackish sea water in a pilot-scale cooling water circuit. Two tests were performed, each employing three test materials, until differences between the materials were detected. Open circuit potential (OCP) was measured continuously in situ. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements were conducted before and after the tests. Exposed specimens were further subjected to examinations by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), and the biofouling was studied using epifluorescence microscopy, quantitative polymerase chain reaction (qPCR) and high-throughput sequencing (HTP sequencing). The results revealed dissimilarities between the stainless steel grades in corrosion behaviour and biofouling tendency. The test material that differed from the most of the other studied alloys was grade EN 1.4162. It experienced fastest and most efficient ennoblement of OCP, its passive area shrank to the greatest extent and the cathodic reaction was accelerated to a significant degree by the development of biofilm. Furthermore, microbiological analyses revealed that bacterial community on EN 1.4162 was dominated by Actinobacteria, whereas on the other five test materials Proteobacteria was the main bacterial phylum.
Domaine de référence : Antifouling
Auteur Huttunen-Saarivirta E., Rajala P., Marja-Aho M., Maukonen J., Sohlberg E., Carpén L.
Année de parution : 2017.
Mots-clés : Biofouling, Brackish sea water, Electrochemical measurements, Ennoblement, Microbially induced corrosion (MIC), Stainless steel.
Type de document : Article de revue.
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Effect of copper on multiple successional stages of a marine fouling assemblage

Résumé : Copper based paints are used to prevent fouling on the hulls of ships. The widely documented effect of copper on hull assemblages may be primarily due to direct effects on the invertebrates themselves or indirect effects from copper absorbed into the microbial biofilm before settlement has commenced. Artificial units of habitat were exposed to varied regimes of copper to examine (1) the photosynthetic efficiency and pigments of early-colonising biofilms, and (2) subsequent macroinvertebrate assemblage change in response to the different regimes of copper. Macroinvertebrate assemblages were found to be less sensitive to the direct effects of copper than indirect effects as delivered through biofilms that have been historically exposed to copper, with some species more tolerant than others. This raises further concern for the efficacy of copper as a universal antifoulant on the hulls of ships, which may continue to assist the invasion of copper-tolerant invertebrate species.
Domaine de référence : Antifouling
Auteur McElroy David J., Hochuli Dieter F., Doblin Martina A., Murphy Richard J., Blackburn Robert J., Coleman Ross A.
Année de parution : 2017.
Mots-clés : Algae, assembly rules, Biofilm, Disturbance, Invasive species, invertebrate.
Type de document : Article de revue.
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Isolation and Antifouling activity of Azulene Derivatives from the Antarctic Gorgonian Acanthogorgia laxa

Résumé : Three azulenoid sesquiterpenes (1- 3) were isolated from the Antarctic gorgonian Acanthogorgia laxa collected by bottom trawls at –343 m. Besides linderazulene (1), and the known ketolactone 2, a new brominated C-16 linderazulene derivative (3) was also identified. This compound has an extra carbon atom at C-7 of the linderazulene framework. The antifouling activity of compounds 1 and 2 was assayed in the laboratory with Artemia salina larvae, and also in field tests, by incorporation in soluble-matrix experimental antifouling paints. The results obtained after a 45 days field trial of the paints, showed that compounds 1 and 2 displayed good antifouling potencies against a wide array of organisms. Compound 3, a benzylic bromide, was unstable and for this reason was not submitted to bioassays. Two known cembranolides: pukalide and epoxypukalide, were also identified as minor components of the extract. This article is protected by copyright. All rights reserved.
Domaine de référence : Antifouling
Auteur Patiño C Laura P., Manfredi Rodrigo Quintana, Pérez Miriam, García Mónica, Blustein Guillermo, Cordeiro Ralf, Pérez Carlos D., Schejter Laura, Palermo Jorge A.
Année de parution : 2017.
Mots-clés : Acanthogorgiidae, antifouling activity, azulene sesquiterpenoids, marine natural products, Octocorals.
Type de document : Article de revue.
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Marine antifouling performance of polymer coatings incorporating zwitterions

Résumé : Zwitterionic materials display antifouling promise, but their potential in marine anti-biofouling is still largely unexplored. This study evaluates the effectiveness of incorporating small quantities (0–20% on a molar basis) of zwitterions as sulfobetaine methacrylate (SBMA) or carboxybetaine methacrylate (CBMA) into lauryl methacrylate-based coatings whose relatively hydrophobic nature encourages adhesion of the diatom Navicula incerta, a common microfouling organism responsible for the formation of ‘slime’. This approach allows potential enhancements in antifouling afforded by zwitterion incorporation to be easily quantified. The results suggest that the incorporation of CBMA does provide a relatively minor enhancement in fouling-release performance, in contrast to SBMA which does not display any enhancement. Studies with coatings incorporating mixtures of varying ratios of the cationic monomer [2-(methacryloyloxy)ethyl]trimethylammonium chloride and the anionic monomer (3-sulfopropyl)methacrylate, which offer a potentially lower cost approach to the incorporation of anionic and cationic charge, suggest these monomers impart little significant effect on biofouling.
Domaine de référence : Antifouling
Auteur Ventura Claudia, Guerin Andrew J., El-Zubir Osama, Ruiz-Sanchez Antonio J., Dixon Luke I., Reynolds Kevin J., Dale Marie L., Ferguson James, Houlton Andrew, Horrocks Benjamin R., Clare Anthony S., Fulton David A.
Année de parution : 2017.
Type de document : Article de revue.
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Antifouling and Photocatalytic Antibacterial Activity of the AquaSun Coating in Seawater and Related Media

Résumé : Prolonged testing of the new xerogel photocatalytic coating AquaSun applied to a surface probe immersed in ocean water irradiated with simulated solar radiation shows excellent action against biofouling. Activated by moderate solar radiation, the organosilica film has also good antimicrobial properties. Considering the high stability, the environmental footprint, and the low cost of this sol–gel marine coating, the technology has significant potential toward replacing conventional antifouling and foul-release coatings with a single product of broad applicability.
Domaine de référence : Antifouling
Auteur Scandura Gabriele, Ciriminna Rosaria, Ozer Lütfiye Yıldız, Meneguzzo Francesco, Palmisano Giovanni, Pagliaro Mario
Année de parution : 2017.
Type de document : Article de revue.
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Minireview : algal natural compounds and extracts as antifoulants

Résumé : Marine biofouling is a paramount phenomenon in the marine environment and causes serious problems to maritime industries worldwide. Marine algae are known to produce a wide variety of chemical compounds with antibacterial, antifungal, antialgal, and anti-macrofouling properties, inhibiting the settlement and growth of other marine fouling organisms. Significant investigations and progress have been made in this field in the last two decades and several antifouling extracts and compounds have been isolated from micro- and macroalgae. In this minireview, we have summarized and evaluated antifouling compounds isolated and identified from macroalgae and microalgae between January 2010 and June 2016. Future directions for their commercialization through metabolic engineering and industrial scale up have been discussed. Upon comparing biogeographical regions, investigations from Southeast Asian waters were found to be rather scarce. Thus, we have also discussed the need to conduct more chemical ecology based research in relatively less explored areas with high algal biodiversity like Southeast Asia.
Domaine de référence : Antifouling
Auteur Saha Mahasweta, Goecke Franz, Bhadury Punyasloke
Année de parution : 2017.
Type de document : Article de revue.
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Potential ecotoxicity of metals leached from antifouling paint particles under different salinities

Résumé : Antifouling paint particles (APPs) are residues generated during maintenance of vessels. In boat maintenance areas of South America, waste generation and disposal are not completely regulated. Therefore, APPs can enter into the aquatic environment and act as a source of contamination by metals and other biocides. Thus, the aim of the present study was to evaluate the potential ecotoxicity of the metal mixture present in APPs leached under different salinities. Therefore, the copepod Acartia tonsa was exposed to different concentrations of a leachate solution prepared by the addition of APPs (1.25 g/L) in artificial saline water (salinities 5, 15 and 30). Thereafter, complexing agents (EDTA and sodium thiosulfate) were added to the experimental media in order to evaluate metal influence in APPs toxicity. APPs leachate solutions were very toxic to A. tonsa, reaching an estimated LC50 of 1% at salinities 5% and 15%, and 2% at salinity 30. The addition of the chelators in leachate solutions showed that metals are the major responsible compounds for the observed toxicity. Moreover, results from the calculated toxic units suggested a slightly synergic effect between Cu and Zn in the paint formulation. A metal speciation modelling showed that Zn was predominant as a free ion at all salinities, therefore, explaining the high leachate toxicity. Furthermore, the release of Zn was observed more at lower salinities, whereas Cu was observed at higher salinities. APPs are frequently released in estuarine systems, under conditions of salinity gradients. Therefore, navigated estuaries might be under the threat of this neglected residue.
Domaine de référence : Antifouling
Auteur Soroldoni Sanye, Martins Samantha Eslava, Castro Italo Braga, Pinho Grasiela Lopes Leães
Année de parution : 2018.
Mots-clés : Acartia tonsa, Antifouling paint particles, Biocides, Ecotoxicity, Leachate, Metal mixture.
Type de document : Article de revue.
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Intelligent Image Recognition System for Marine Fouling Using Softmax Transfer Learning and Deep Convolutional Neural Networks

Résumé : The control of biofouling on marine vessels is challenging and costly. Early detection before hull performance is significantly affected is desirable, especially if “grooming” is an option. Here, a system is described to detect marine fouling at an early stage of development. In this study, an image of fouling can be transferred wirelessly via a mobile network for analysis. The proposed system utilizes transfer learning and deep convolutional neural network (CNN) to perform image recognition on the fouling image by classifying the detected fouling species and the density of fouling on the surface. Transfer learning using Google’s Inception V3 model with Softmax at last layer was carried out on a fouling database of 10 categories and 1825 images. Experimental results gave acceptable accuracies for fouling detection and recognition.
Domaine de référence : Antifouling
Auteur Chin C. S., Si JianTing, Clare A. S., Ma Maode
Année de parution : 2017.
Type de document : Article de revue.
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The Antifouling of ACLW-CAR Based on Ultrasonic Cleaner

Résumé : Equipped with ACLW-CAR, the buoy provided effective technical platform for on-site rapid monitoring of the chlorophyll and turbidity. Performance index and usage in the ocean buoy of ACLW-CAR was introduced. Ultrasonic cleaning method in seawater was developed for preventing ACLW-CAR from biofouling. Marine chlorophyll and turbidity data can serve for oceanographic research and marine resource exploitation.
Domaine de référence : Antifouling
Auteur Zhang Guohua, Liu Shixuan, Qin Qingliang
Année de parution : 2017.
Type de document : Article de revue.
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Effect of organic on chemical oxidation for biofouling control in pilot-scale seawater cooling towers

Résumé : Due to the scarcity of potable water in many regions of the world, the demand for seawater as an alternative evaporative cooling medium in cooling towers (CTs) has increased significantly in recent years. Seawater make-up in CTs is deemed the most feasible because of its unlimited supply in the coastal areas of Gulf and Red Sea. However, the seawater CTs have higher challenges greatly mitigating their performances because it is an open system where biofouling and bio-corrosion occurring within the fillers and piping of recirculation systems. Their pilot-scale CTs were constructed to assess the performance of three types of oxidizing biocides or oxidants, namely chlorine, chlorine dioxide (ClO2) and ozone, for biofouling control. The test results showed that the addition of organic (5mg/L of methanol (MeOH)) increased the bacterial growth in CT basin. All oxidants were effective in keeping the microbial growth to the minimum. Oxidation increased the oxidation-reduction potential (ORP) level from 270 to 600mV. Total residual oxidant (TRO) was increased with oxidation but it was slightly increased with organic addition. Other parameters including pH, dissolved oxygen (DO), conductivity levels were not changed. However, higher formation of disinfection by-products (DBPs) was detected with chlorination and ozonation. This indicates the organic level should be limited in the oxidation for biofouling control in seawater CTs.
Domaine de référence : Antifouling
Auteur Al-Bloushi Mohammed, Saththasivam Jayaprakash, Jeong Sanghyun, Amy Gary L., Leiknes TorOve
Année de parution : 2017.
Type de document : Article de revue.
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Effect of barnacle fouling on ship resistance and powering

Résumé : Predictions of added resistance and the effective power of ships were made for varying barnacle fouling conditions. A series of towing tests was carried out using flat plates covered with artificial barnacles. The tests were designed to allow the examination of the effects of barnacle height and percentage coverage on the resistance and effective power of ships. The drag coefficients and roughness function values were evaluated for the flat plates. The roughness effects of the fouling conditions on the ships’ frictional resistances were predicted. Added resistance diagrams were then plotted using these predictions, and powering penalties for these ships were calculated using the diagrams generated. The results indicate that the effect of barnacle size is significant, since a 10% coverage of barnacles each 5 mm in height caused a similar level of added power requirements to a 50% coverage of barnacles each 1.25 mm in height.
Domaine de référence : Antifouling
Auteur Demirel Yigit Kemal, Uzun Dogancan, Zhang Yansheng, Fang Ho-Chun, Day Alexander H., Turan Osman
Année de parution : 2017.
Mots-clés : added resistance, Artificial barnacles, Biofouling, experiment, powering.
Type de document : Article de revue.
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Compositions and Method for Inhibiting Biofouling and Barnacle Growth on Substrates Under Water

Résumé : The invention provides a marine antifouling composition comprising: (a) 1 to 50% by weight of a cylic volatile methylsiloxane selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopenta-siloxane and dodeca-methylcyclohexasiloxane; (b) 1 to 20% of a surfactant selected from the group consisting of polyoxyethylene monostearate, steareth-40, octylphenoxy polyethoxyethanol, steareth-20, and a C11-C15 secondary alcohol ethoxylate; and (c) the balance water.
Domaine de référence : Antifouling
Auteur Cabot JR Carl G.
Année de parution : 2017.
Type de document : Brevet.
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Hull Inspection Techniques and Strategy - Remote Inspection Developments

Résumé : In 2013 the Hull Inspection Techniques and Strategies (HITS) paper SPE-13OE-P-409-SPE [ 1 ], introduced and outlined the HITS joint industry project (JIP) objectives. This paper summarises the JIP&#39;s progress and the success achieved to date. It
Domaine de référence : Antifouling
Auteur Caldwell Raymond
Année de parution : 2017.
Type de document : Article de colloque.
Source : Society of Petroleum Engineers
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Comparative study of mechanical and chemical methods for surface cleaning of a marine shell-and-tube heat exchanger

Résumé : In this article, experimental analysis is done on shell-and-tube heat exchanger of a marine vessel for removal of fouling using optimum surface-cleaning techniques. The main objective is to compare the performance of the heat exchanger before and after maintenance. Two identical deteriorated systems of heat exchangers are taken and real-time analysis is conducted. The log data are taken before and after undergoing maintenance for the two systems. Two different cleaning techniques are used, namely, chemical cleaning and mechanical cleaning. Detailed calculations are made for the shell-and-tube heat exchanger. From the obtained data, comparisons are made for different parameters on the tube side such as friction factor, heat transfer coefficient and pressure drop, as well as total heat transfer rate on the shell side. From the analysis and comparison, it was found that greater heat transfer takes place for the tubes cleaned using the chemical cleaning method than for tubes cleaned by the mechanical cleaning method. Pressure drop is found to be less for chemical cleaning method than mechanical cleaning method. This indicates that the fouling effect is reduced for tubes cleaned by the chemical cleaning method, and furthermore these tubes remain corrosion-resistant for longer periods of time.
Domaine de référence : Antifouling
Auteur P.s Kishore, Kumar Rajnish, N Vamsi Venkata
Année de parution : 2017.
Mots-clés : cleaning methods, Fouling, friction factor, heat transfer coefficient, pressure drop, shell-and-tube heat exchanger.
Type de document : Article de revue.
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Measuring a critical stress for continuous prevention of marine biofouling accumulation with aeration

Résumé : When cleaning the hull of a ship, significant shear stresses are needed to remove established biofouling organisms. Given that there exists a link between the amount of time that fouling accumulates and the stress required to remove it, it is not surprising that more frequent grooming requires less shear stress. Yet, it is unclear if there is a minimum stress needed to prevent the growth of macrofouling in the limit of continuous grooming. This manuscript shows that single bubble stream aeration provides continuous grooming and prevents biofouling accumulation in regions where the average wall stress exceeds 0.01 Pa. This value was found by comparing observations of biofouling growth from field studies with complementary laboratory measurements that probe the associated flow fields. These results suggest that aeration and other continuous grooming systems must exceed a wall stress of 0.01 Pa to prevent macrofouling accumulation.
Domaine de référence : Antifouling
Auteur Menesses Mark, Belden Jesse, Dickenson Natasha, Bird James
Année de parution : 2017.
Mots-clés : AERATION, bubble, grooming, shear stress.
Type de document : Article de revue.
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Antifouling Compounds from Marine Macroalgae

Résumé : Marine macroalgae produce a wide variety of biologically-active metabolites that have been developed into commercial products, such as antibiotics, immunosuppressive, anti-inflammatory, cytotoxic agents, and cosmetic products. Many marine algae remain clean over longer periods of time, suggesting their strong antifouling potential. Isolation of biogenic compounds and the determination of their structure could provide leads for the development of environmentally-friendly antifouling paints. Isolated substances with potent antifouling activity belong to fatty acids, lipopeptides, amides, alkaloids, lactones, steroids, terpenoids, and pyrroles. It is unclear as yet to what extent symbiotic microorganisms are involved in the synthesis of these compounds. Algal secondary metabolites have the potential to be produced commercially using genetic and metabolic engineering techniques. This review provides an overview of publications from 2010 to February 2017 about antifouling activity of green, brown, and red algae. Some researchers were focusing on antifouling compounds of brown macroalgae, while metabolites of green algae received less attention. Several studies tested antifouling activity against bacteria, microalgae and invertebrates, but in only a few studies was the quorum sensing inhibitory activity of marine macroalgae tested. Rarely, antifouling compounds from macroalgae were isolated and tested in an ecologically-relevant way.
Domaine de référence : Antifouling
Auteur Dahms Hans Uwe, Dobretsov Sergey
Année de parution : 2017.
Mots-clés : Antifouling, Biofouling, biogenic compounds, macroalgae, marine natural products, Quorum sensing.
Type de document : Article de revue.
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Review on Molecular Mechanisms of Antifouling Compounds : An Update since 2012

Résumé : Better understanding of the mechanisms of antifouling compounds is recognized to be of high value in establishing sensitive biomarkers, allowing the targeted optimization of antifouling compounds and guaranteeing environmental safety. Despite vigorous efforts to find new antifouling compounds, information about the mechanisms of antifouling is still scarce. This review summarizes the progress into understanding the molecular mechanisms underlying antifouling activity since 2012. Non-toxic mechanisms aimed at specific targets, including inhibitors of transmembrane transport, quorum sensing inhibitors, neurotransmission blockers, adhesive production/release inhibitors and enzyme/protein inhibitors, are put forward for natural antifouling products or shelf-stable chemicals. Several molecular targets show good potential for use as biomarkers in future mechanistic screening, such as acetylcholine esterase for neurotransmission, phenoloxidase/tyrosinase for the formation of adhesive plaques, N-acyl homoserine lactone for quorum sensing and intracellular Ca2+ levels as second messenger. The studies on overall responses to challenges by antifoulants can be categorized as general targets, including protein expression/metabolic activity regulators, oxidative stress inducers, neurotransmission blockers, surface modifiers, biofilm inhibitors, adhesive production/release inhibitors and toxic killing. Given the current situation and the knowledge gaps regarding the development of alternative antifoulants, a basic workflow is proposed that covers the indispensable steps, including preliminary mechanism- or bioassay-guided screening, evaluation of environmental risks, field antifouling performance, clarification of antifouling mechanisms and the establishment of sensitive biomarkers, which are combined to construct a positive feedback loop.
Domaine de référence : Antifouling
Auteur Chen Lianguo, Qian Pei-Yuan
Année de parution : 2017.
Mots-clés : antifouling compounds, Degradation, general targets, molecular mechanisms, specific targets, Toxicity.
Type de document : Article de revue.
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New Marine Antifouling Compounds from the Red Alga Laurencia sp.

Résumé : Six new compounds, omaezol, intricatriol, hachijojimallenes A and B, debromoaplysinal, and 11,12-dihydro-3-hydroxyretinol have been isolated from four collections of Laurencia sp. These structures were determined by MS and NMR analyses. Their antifouling activities were evaluated together with eight previously known compounds isolated from the same samples. In particular, omaezol and hachijojimallene A showed potent activities (EC50 = 0.15–0.23 µg/mL) against larvae of the barnacle Amphibalanus amphitrite.
Domaine de référence : Antifouling
Auteur Oguri Yuko, Watanabe Mami, Ishikawa Takafumi, Kamada Takashi, Vairappan Charles S., Matsuura Hiroshi, Kaneko Kensuke, Ishii Takahiro, Suzuki Minoru, Yoshimura Erina, Nogata Yasuyuki, Okino Tatsufumi
Année de parution : 2017.
Mots-clés : acetogenin, Antifouling, Barnacle, Biofouling, Laurencia, Rhodophyta, terpenoid.
Type de document : Article de revue.
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Antifouling Compounds from Marine Invertebrates

Résumé : In this review, a comprehensive overview about the antifouling compounds from marine invertebrates is described. In total, more than 198 antifouling compounds have been obtained from marine invertebrates, specifically, sponges, gorgonian and soft corals.
Domaine de référence : Antifouling
Auteur Qi Shu-Hua, Ma Xuan
Année de parution : 2017.
Mots-clés : antifouling compound, coral, marine invertebrate, sponge.
Type de document : Article de revue.
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The anti-bacterial effect of an electrochemical anti-fouling method intended for the protection of miniaturised oceanographic sensors

Résumé : An electrochemical anti-fouling method, based upon the generation of chlorine from seawater, was applied to a proprietary design of Lab on a Chip conductivity, temperature and dissolved oxygen sensor. The method was evaluated using PCR after a six-week field trial in which it significantly reduced the burden of bacterial biofouling.
Domaine de référence : Antifouling
Auteur McQuillan Jonathan S., Morris Andrew K., Arundell Martin, Pascal Robin, Mowlem Matthew C.
Année de parution : 2017.
Type de document : Article de revue.
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Superhydrophilic Conversion of Stainless Steel Surfaces by Biomimetic Silica Coating and Its Effect on Marine Fouling

Domaine de référence : Antifouling
Auteur Jeong Yeonwoo, Ko Sangwon, Kang Sung Min
Année de parution : 2017.
Mots-clés : Marine fouling, Silica coating, Stainless Steel.
Type de document : Article de revue.
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Study on Antimicrobial Surface Design Using Biological Modification Attempting for Marine Antifouling

Résumé : Antifouling and drag reduction is an important part of ship tribology. During the process of fouling, bacterial biofilms formation is the first step. Algae, barnacles and shells and other large bio fouling organisms attach on the hull becau
Domaine de référence : Antifouling
Auteur Yuan Chengqing, Cao Pan, Bai Xiuqin
Année de parution : 2017.
Type de document : Article de colloque.
Source : International Society of Offshore and Polar Engineers
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Facile preparation of robust and superhydrophobic materials for self-cleaning and oil/water separation

Résumé : Superhydrophobic coatings have broad applications owing to their excellent water-resisting and self-cleaning properties. In this study, we have successfully fabricated coated meshes with robust and superhydrophobic surface (i.e., water-repellent magnesium stearate powders on substrates made of phenol-formaldehyde resin). These coated meshes showed superhydrophobicity with water contact angles exceeding 150° and excellent self-cleaning property both in air and oil circumstances. Additionally, the superhydrophobic surfaces also exhibited prominent mechanical stability, thermal stability, corrosion resistance, and oil/water separation properties (>92%). Therefore, it is believed that the facile fabrication presented in this study may provide a novel methodology and these robust and superhydrophobic coated meshes have potential applications in oil/water separation.
Domaine de référence : Antifouling
Auteur Cao Wen-Tao, Liu Yan-Jun, Ma Ming-Guo, Zhu Jie-Fang
Année de parution : 2017.
Mots-clés : Oil/water separation, Robustness, Self-clean, Superhydrophobicity.
Type de document : Article de revue.
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Electrochemical Approach for Effective Antifouling and Antimicrobial Surfaces

Résumé : Biofouling, the adsorption of organisms to a surface, is a major problem today in many areas of our lives. This includes: (i) health, as biofouling on medical device leads to hospital-acquired infections, (ii) water, since the accumulation of organisms on membranes and pipes in desalination systems harms the function of the system, and (iii) energy, due to the heavy load of the organic layer that accumulates on marine vessels and causes a larger consumption of fuel. This paper presents an effective electrochemical approach for generating antifouling and antimicrobial surfaces. Distinct from previously reported antifouling or antimicrobial electrochemical studies, we demonstrate the formation of a hydrogen gas bubble layer through the application of a low-voltage square-waveform pulses to the conductive surface. This electrochemically generated gas bubble layer serves as a separation barrier between the surroundings and the target surface where the adhesion of bacteria can be deterred. Our results indicate that this barrier could effectively reduce the adsorption of bacteria to the surface by 99.5%. We propose that the antimicrobial mechanism correlates with the fundamental of hydrogen evolution reaction (HER). HER leads to an arid environment that does not allow the existence of live bacteria. In addition, we show that this drought condition kills the preadhered bacteria on the surface due to water stress. This work serves as the basis for the exploration of future self-sustainable antifouling techniques such as incorporating it with photocatalytic and photoelectrochemical reactions.
Domaine de référence : Antifouling
Auteur Gaw Sheng Long, Sarkar Sujoy, Nir Sivan, Schnell Yafit, Mandler Daniel, Xu Zhichuan J., Lee Pooi See, Reches Meital
Année de parution : 2017.
Type de document : Article de revue.
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Fabrication of superhydrophobic coatings for combating bacterial colonization on Al with relevance to marine and medical applications

Résumé : Aluminum and its alloys are widely used in almost all industries and for marine and medical applications. However, their surfaces are easily colonized by bacteria that form biofilms and corroded by chemical reactions. We report here a simple method to fabricate polyaniline/chitosan/zinc stearate superhydrophobic coatings on aluminum with a micro–nanosurface structure by polymerization of aniline and deposition of chitosan and zinc stearate coating. The fabricated coatings have been characterized by ATR-IR, XRD, FE-SEM, and EDX. The superhydrophobic surface shows the highest water-repellent property with contact angle of 150.7°, which is responsible for antiadhesion of bacteria, antiicing property, and excellent corrosion resistance of aluminum. The corrosion behavior of the coating in the 3.5% NaCl solution was investigated by EIS and potentiodynamic polarization. The efficacies of the different coatings against bacteria that are commonly encountered in marine (Desulfovibrio desulfuricans) and medical applications (Staphylococcus aureus and Escherichia coli) are demonstrated.Graphical AbstractOpen image in new window
Domaine de référence : Antifouling
Auteur Raj R. Mohan, Raj V.
Année de parution : 2017.
Type de document : Article de revue.
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Recent progress in marine foul-release polymeric nanocomposite coatings

Résumé : Progress in materials science is associated with the development of nanomaterials in terms of energy-saving, environmentally friendly, and low-cost methods. Since the use of tributyltin compounds in antifouling coatings was banned in 2003, the search for ecofriendly alternatives has been promoted. Foul-release (FR) nanocoatings have been extensively investigated because of their non-stick, ecological, and economic advantages. Such nanocomposite systems are dynamic non-stick surfaces that deter any fouling attachment through physical anti-adhesion terminology. Instead of biocidal solutions, several functional FR nanocomposite coatings have been developed to counter biofouling and biocorrosion with ecological and ecofriendly effects. Selected inorganic nanofillers have been incorporated because of their enhanced interaction at the filler‐polymer interface for nanocomposites. Metallic nanoparticles and their oxides have also been widely explored because of their unique morphological characteristics and size-dependent, self-cleaning properties. In modeling a novel series of FR nanocoatings, two modes of prevention are combined: chemical inertness and physical microfouling repulsion for maritime navigation applications. Long-term durability and self-cleaning performance are among the advantages of developing effective, stable, and ecofriendly modeling alternatives. This review provides a holistic overview of nano-FR research achievements and describes recent advancements in non-stick marine nanocoatings for ship hulls. This review highlights the key issues of nanocomposite structures and their features in improving the biological activity and surface self-cleaning performance of ship hulls. This review may also open new horizons toward futuristic developments in FR nanocomposites for maritime navigations.
Domaine de référence : Antifouling
Auteur Selim M. S., Shenashen M. A., El-Safty Sherif A., Higazy S. A., Selim M. M., Isago H., Elmarakbi A.
Année de parution : 2017.
Mots-clés : environment, Foul-release (FR), inorganic nanofillers, nanocoatings, Polymeric Nanocomposite.
Type de document : Article de revue.
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Early bacterial biofilm colonizers in the coastal waters of Mauritius

Résumé : Background The past years have witnessed a growing number of researches in biofilm forming communities due to their environmental and maritime industrial implications. To gain a better understanding of the early bacterial biofilm community, microfiber nets were used as artificial substrates and incubated for a period of 24 h in Mauritian coastal waters. Next-generation sequencing technologies were employed as a tool for identification of early bacterial communities. Different genes associated with quorum sensing and cell motility were further investigated. Results Proteobacteria were identified as the predominant bacterial microorganisms in the biofilm within the 24 h incubation, of which members affiliated to Gammaproteobacteria, Alphaproteobacteria and Betaproteobacteria were among the most abundant classes. The biofilm community patterns were also driven by phyla such as Firmicutes, Bacteroidetes, Chloroflexi, Actinobacteria and Verrucomicrobia. The functional analysis based on KEGG classification indicated high activities in carbohydrate, lipid and amino acids metabolism. Different genes encoding for luxI, lasI, agrC, flhA, cheA and cheB showed the involvement of microbial members in quorum sensing and cell motility. Conclusion This study provides both an insight on the early bacterial biofilm forming community and the genes involved in quorum sensing and bacterial cell motility.
Domaine de référence : Antifouling
Auteur Rampadarath Sillma, Bandhoa Kushlata, Puchooa Daneshwar, Jeewon Rajesh, Bal Subhasisa
Année de parution : 2017.
Mots-clés : Bacterial Adhesion, Biofouling, Cell motility, Coastal waters, Functional metagenomics, Identification bacterial communities, Metatranscriptomic, Next-generation sequencing technologies, Proteobacteria, Quorum sensing.
Type de document : Article de revue.
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A marine bacterial adhesion microplate test using the DAPI fluorescent dye : a new method to screen antifouling agents

Résumé : Aims: To develop a method to screen antifouling agents against marine bacterial adhesion as a sensitive, rapid, quantitative microplate fluorescent test. Methods and Results: Our experimental method is based on a natural biofilm formed by mono-incubation of the marine bacterium Pseudoalteromonas sp. D41 in sterile natural sea water in a 96 wells polystyrene microplate. The 4'6-diamidino-2-phenylindole (DAPI) dye was used to quantify adhered bacteria in each well. Total measured fluorescence in wells was correlated with the amount of bacteria showing a detection limit of one bacterium per 5 µm2 and quantifying 2 x 107 to 2 x 108 bacteria adhered per cm2. The antifouling properties of three commercial surface active agents and chlorine were tested by this method in prevention of adhesion and also in detachment of already adhered bacteria. The marine bacterial adhesion inhibition rate depending on agent concentration showed a sigmoid shape like dose-response curve. Conclusions: This test is well adapted for a rapid and quantitative first screening of antifouling agents directly in seawater in the early steps of marine biofilm formation. Significance and impact of the study: In contrast with usual screenings of antifouling products which detect a bactericidal activity, this test is more appropriate to screen antifouling agents for bacterial adhesion removal or bacterial adhesion inhibition activities. This screening test focuses on antifouling properties of products, especially the first steps of marine biofilm formation.
Domaine de référence : Antifouling
Auteur Leroy Celine, Delbarre Ladrat Christine, Ghillebaert F., Rochet Marie-Joelle, Compere Chantal, Combes D.
Année de parution : 2007.
Type de document : Article de revue.
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Biodiversity characterisation and hydrodynamic consequences of marine fouling communities on marine renewable energy infrastructure in the Orkney Islands Archipelago, Scotland, UK

Résumé : As part of ongoing commitments to produce electricity from renewable energy sources in Scotland, Orkney waters have been targeted for potential large-scale deployment of wave and tidal energy converting devices. Orkney has a well-developed infrastructure supporting the marine energy industry; recently enhanced by the construction of additional piers. A major concern to marine industries is biofouling on submerged structures, including energy converters and measurement instrumentation. In this study, the marine energy infrastructure and instrumentation were surveyed to characterise the biofouling. Fouling communities varied between deployment habitats; key species were identified allowing recommendations for scheduling device maintenance and preventing spread of invasive organisms. A method to measure the impact of biofouling on hydrodynamic response is described and applied to data from a wave-monitoring buoy deployed at a test site in Orkney. The results are discussed in relation to the accuracy of the measurement resources for power generation. Further applications are suggested for future testing in other scenarios, including tidal energy.
Domaine de référence : Antifouling
Auteur Want Andrew, Crawford Rebecca, Kakkonen Jenni, Kiddie Greg, Miller Susan, Harris Robert E., Porter Joanne S.
Année de parution : 2017.
Mots-clés : Biofouling, buoy, floating pontoon, harbour, invasive non-native species, wave.
Type de document : Article de revue.
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Anti-Biofilm Effect of Biodegradable Coatings Based on Hemibastadin Derivative in Marine Environment

Résumé : Dibromohemibastadin-1 (DBHB) is an already known potent inhibitor of blue mussel phenoloxidase (which is a key enzyme involved in bioadhesion). Within this study, the potentiality of DBHB against microfouling has been investigated. The activity of DBHB was evaluated on key strains of bacteria and microalgae involved in marine biofilm formation and bioassays assessing impact on growth, adhesion and biofilm formation were used. To assess the efficiency of DBHB when included in a matrix, DBHB varnish was prepared and the anti-microfouling activity of coatings was assessed. Both in vitro and in situ immersions were carried out. Confocal Laser Scanning Microscopy (CLSM) was principally used to determine the biovolume and average thickness of biofilms developed on the coatings. Results showed an evident efficiency of DBHB as compound and varnish to reduce the biofilm development. The mode of action seems to be based principally on a perturbation of biofilm formation rather than on a biocidal activity in the tested conditions.
Domaine de référence : Antifouling
Auteur Norcy Tiffany Le, Niemann Hendrik, Proksch Peter, Linossier Isabelle, Vallée-Réhel Karine, Hellio Claire, Faÿ Fabienne
Année de parution : 2017.
Mots-clés : Antifouling, biodegradable coating, hemibastadin, Marine bacteria, Microalgae, Sponges.
Type de document : Article de revue.
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Self-repairing silicone coating for marine anti-biofouling

Résumé : Marine biofouling is one of the most challenging problems today. Silicone polymer based coatings with low surface energy and elastic modulus can effectively inhibit or release biofouling. However, their non-repairable property and poor antifouling ability on static conditions limit their applications. Here, we report a self-repairing coating consisting of poly(dimethylsiloxane) based polyurea (PDMS-PUa) and a small amount of organic antifoulant (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) (DCOIT). The coating can completely recover itself from damaging in mechanical properties either in air or artificial seawater at room temperature. Such recovery can be accelerated at a higher temperature. Moreover, the release rate of DCOIT is almost constant and can be regulated by its concentration. The six-month marine field tests demonstrate that the system has a good antifouling/fouling release performance even on static conditions.
Domaine de référence : Antifouling
Auteur Liu Chao, Ma Chunfeng, Xie Qingyi, Zhang Guangzhao
Année de parution : 2017.
Type de document : Article de revue.
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The effect of marine growth dynamics in offshore wind turbine support structures

Domaine de référence : Antifouling
Auteur Martinez-Luengo M, Causon P, Gill Ab, Kolios Aj
Année de parution : 2017.
Type de document : Chapitre de livre.
Source : CRC Press/Balkema
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Bioinspired nanocoatings for biofouling prevention by photocatalytic redox reactions

Résumé : Aquaculture is a billion dollar industry and biofouling of aquaculture installations has heavy economic penalties. The natural antifouling (AF) defence mechanism of some seaweed that inhibits biofouling by production of reactive oxygen species (ROS) inspired us to mimic this process by fabricating ZnO photocatalytic nanocoating. AF activity of fishing nets modified with ZnO nanocoating was compared with uncoated nets (control) and nets painted with copper-based AF paint. One month experiment in tropical waters showed that nanocoatings reduce abundances of microfouling organisms by 3-fold compared to the control and had higher antifouling performance over AF paint. Metagenomic analysis of prokaryotic and eukaryotic fouling organisms using next generation sequencing platform proved that nanocoatings compared to AF paint were not selectively enriching communities with the resistant and pathogenic species. The proposed bio-inspired nanocoating is an important contribution towards environmentally friendly AF technologies for aquaculture.
Domaine de référence : Antifouling
Auteur Sathe Priyanka, Laxman Karthik, Myint Myo Tay Zar, Dobretsov Sergey, Richter Jutta, Dutta Joydeep
Année de parution : 2017.
Type de document : Article de revue.
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Environmentally Friendly Antifouling Coatings Based on Biodegradable Polymer and Natural Antifoulant

Résumé : Marine biofouling causes huge economic losses and serious problems to maritime industries. Consequently, there is a great demand for environmentally friendly antibiofouling technology. In the present study, we developed novel antifouling coatings by incorporating butenolide derived from marine bacteria into biodegradable poly(ε-caprolactone) based polyurethane. Measurements of mass loss indicated that the polymer was degraded in seawater and that the degradation rate increased in the presence of marine organisms or enzymes. Moreover, measured release rates indicated that butenolide could be released from the biodegradable polymer for at least 3 months and the release rate depended on both the concentration of butenolide and the temperature. Incorporating a naturally occurring resin (rosin) into the biodegradable polymer increased the self-renewal rate and improved the later release rate of butenolide. The field test indicated that the system had excellent antifouling properties.
Domaine de référence : Antifouling
Auteur Ma Chunfeng, Zhang Weipeng, Zhang Guangzhao, Qian Pei-Yuan
Année de parution : 2017.
Type de document : Article de revue.
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Characterization of biofilm-forming marine bacteria and their effect on attachment and germination of algal spores

Résumé : In this work, 37 bacterial strains isolated from biofouling of marine organisms and from the Museum of Heterotrophic Bacteria of the National Scientific Center of Marine Biology were studied. The strains were identified based on their phenotypic characteristics and on the fatty acid composition of their cell wall lipids. Members of the genus Pseudoalteromonas prevailed both in associated microflora of two dinoflagellate clones and in the biofilms from marine hydrobionts. Associated microflora included also members of the CFB cluster, Bacillus, Sulfitobacter, Acinetobacter, Shewanella, and Psychrobacter. A considerable portion of strains (48.6%) exhibited antimicrobial activity. Antifouling activity against algal spores was studied using single-species bacterial biofilms and the spores of Ulva lactuca и Undaria pinnatifida, the algae most common in the Sea of Japan. Strong inhibitory effect on attachment of Ulva and Undaria spores was observed for 75 and 51% of the strains, respectively. Attached spores were, however, less sensitive to the inhibitory action of biofilms. Species specificity of algal response to bacteria was shown, with a strain having different effect on the spores of different algal species. Biotechnologically promising strains were determined, which exhibited high activity against the spores of macroalgae and could probably be used as producers of antifouling substances and as components of antifouling coatings. No relation was found between antifouling activity of bacteria and the source of their isolation. Our results indicate wide occurrence of bacteria with antifouling activity among associated microflora of marine hydrobionts and demonstrate the extent of complexity and diversity of relations between bacterial biofilms and algal spores.
Domaine de référence : Antifouling
Auteur Beleneva I. A., Skriptsova A. V., Svetashev V. I.
Année de parution : 2017.
Type de document : Article de revue.
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Influence of biomimetic boundary structure on the antifouling performances of siloxane modified resin coatings

Résumé : Boundary structure is an important factor for significantly influencing the settlement of microalgae. In order to investigate the effect of boundary structure on the antifouling performances of biomimetic textured coatings, three different boundary structures were fabricated via biomimetic replication method and evaluated by recording the settlement amount of fouling microalgae including Nitzschia closterium f. minutissima, Phaeodactylum tricornutum and Chlorella. The results showed that imbricate boundary structure was more positive for antifouling, but depressed boundary structure and raised boundary structure played a negative role for antifouling. Especially, the depressed boundary structure displayed the worst antifouling performance which attributed to providing shelters for microalgae. The antifouling mechanism of microalgae settled on the biomimetic textured coatings with different boundary structures was revealed deeply.
Domaine de référence : Antifouling
Auteur Zhang Yanyan, Zhao Wenjie, Chen Zifei, Liu Zhixiong, Cao Huiliang, Zhou Chengxu, Cui Ping
Année de parution : 2017.
Mots-clés : Antifouling, Biomimetic textured coating, Boundary structure, Microalgae.
Type de document : Article de revue.
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Ce projet est financé par le Fonds Européen de Développement Régional, la Région Normandie et le Conseil Départemental de la Manche.