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Offshore Mechanics : Structural and Fluid Dynamics for Recent Applications

Résumé : Covers theoretical concepts in offshore mechanics with consideration to new applications, including offshore wind farms, ocean energy devices, aquaculture, floating bridges, and submerged tunnels This comprehensive book covers important aspects of the required analysis and design of offshore structures and systems and the fundamental background material for offshore engineering. Whereas most of the books currently available in the field use traditional oil, gas, and ship industry examples in order to explain the fundamentals in offshore mechanics, this book uses more recent applications, including recent fixed-bottom and floating offshore platforms, ocean energy structures and systems such as wind turbines, wave energy converters, tidal turbines and hybrid marine platforms. Offshore Mechanics covers traditional and more recent methodologies used in offshore structure modelling (including SPH and hydroelasticity models). It also examines numerical techniques, including computational fluid dynamics and finite element method. Additionally, the book features easy-to-understand exercises and examples. Provides a comprehensive treatment for the case of recent applications in offshore mechanics for researchers and engineers Presents the subject of computational fluid dynamics (CFD) and finite element methods (FEM) along with the high fidelity numerical analysis of recent applications in offshore mechanics Offers insight into the philosophy and power of numerical simulations and an understanding of the mathematical nature of the fluid and structural dynamics with focus on offshore mechanic applications Offshore Mechanics: Structural and Fluid Dynamics for Recent Applications is an important book for graduate and senior undergraduate students in offshore engineering and for offshore engineers and researchers in the offshore industry.
Domaine de référence : EMR
Auteur Karimirad Madjid, Michailides Constantine, Nematbakhsh Ali
Année de parution : 2018.
Mots-clés : Technology & Engineering / Manufacturing, Technology & Engineering / Mechanical.
Type de document : Livre.
Source : John Wiley & Sons
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

A numerical and experimental study of internal solitary wave loads on semi-submersible platforms

Résumé : Using a double-plate wave maker, a series of laboratory experiments of internal solitary wave (ISW) loads on semi-submersible platforms were conducted in a density stratified fluid tank. Combined with experimental results, a numerical flume based on the Navier-Stokes equations in a two-layer fluid is developed to simulate nonlinear interactions between ISWs and a semi-submersible platform. The numerical results of horizontal and vertical forces, as well as torques on the semi-submersible platform also agree well with the experimental measurements. Besides, the numerical results indicate that the horizontal and vertical forces on the semi-submersible platform due to ISWs can be divided into three components, namely the wave pressure-difference forces, viscous pressure-difference forces, and the frictional force which is negligible. For the horizontal force, the wave and viscous pressure-difference components are of the same order, implying that the viscous effect is significant. For the vertical force, the contribution of the viscous pressure-difference is not important. Moreover, the diffraction effect is significant for horizontal force and insignificant for vertical force. Hence, it is feasible to estimate the vertical load using the Froude-Krylov approach.
Domaine de référence : EMR
Auteur Wang Xu, Zhou Ji-Fu, Wang Zhan, You Yun-Xiang
Année de parution : 2018.
Mots-clés : Internal solitary waves, Semi-submersible platform, Wave loads.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Characterisation of Tidal Flows at the European Marine Energy Centre in the Absence of Ocean Waves

Résumé : The data analyses and results presented here are based on the field measurement campaign of the Reliable Data Acquisition Platform for Tidal (ReDAPT) project (Energy Technologies Institute (ETI), U.K. 2010–2015). During ReDAPT, a 1 MW commercial prototype tidal turbine was deployed and operated at the Fall of Warness tidal test site within the European Marine Energy Centre (EMEC), Orkney, U.K. Mean flow speeds and Turbulence Intensity (TI) at multiple positions proximal to the machine are considered. Through the implemented wave identification techniques, the dataset can be filtered into conditions where the effects of waves are present or absent. Due to the volume of results, only flow conditions in the absence of waves are reported here. The analysis shows that TI and mean flows are found to vary considerably between flood and ebb tides whilst exhibiting sensitivity to the tidal phase and to the specification of spatial averaging and velocity binning. The principal measurement technique was acoustic Doppler profiling provided by seabed-mounted Diverging-beam Acoustic Doppler Profilers (D-ADP) together with remotely-operable Single-Beam Acoustic Doppler Profilers (SB-ADP) installed at mid-depth on the tidal turbine. This novel configuration allows inter-instrument comparisons, which were conducted. Turbulence intensity averaged over the rotor extents of the ReDAPT turbine for flood tides vary between 16.7% at flow speeds above 0.3 m/s and 11.7% when considering only flow speeds in the turbine operating speed range, which reduces to 10.9% (6.8% relative reduction) following the implementation of noise correction techniques. Equivalent values for ebb tides are 14.7%, 10.1% and 9.3% (7.9% relative reduction). For flood and ebb tides, TI values resulting from noise correction are reduced in absolute terms by 3% and 2% respectively across a wide velocity range and approximately 1% for turbine operating speeds. Through comparison with SB-ADP-derived mid-depth TI values, this correction is shown to be conservative since uncorrected SB-ADP results remain, in relative terms, between 10% and 21% below corrected D-ADP values depending on tidal direction and the range of velocities considered. Results derived from other regions of the water column, those important to floating turbine devices for example, are reported for comparison.
Domaine de référence : EMR
Auteur Sellar Brian G., Wakelam Gareth, Sutherland Duncan R. J., Ingram David M., Venugopal Vengatesan
Année de parution : 2018.
Mots-clés : acoustic Doppler profiling, the ReDAPT project, tidal energy, tidal resource characterisation, turbulence intensity, wave-current interaction.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Integrated System Design for a Large Wind Turbine Supported on a Moored Semi-Submersible Platform

Résumé : Over the past few decades, wind energy has emerged as an alternative to conventional power generation that is economical, environmentally friendly and, importantly, renewable. Specifically, offshore wind energy is being considered by a number of countries to harness the stronger and more consistent wind resource compared to that over land. To meet the projected “20% energy from wind by 2030” scenario that was announced in 2006, 54 GW of added wind energy capacity need to come from offshore according to a National Renewable Energy Laboratory (NREL) study. In this study, we discuss the development of a semi-submersible floating offshore platform with a catenary mooring system to support a very large 13.2-MW wind turbine with 100-m blades. An iterative design process is applied to baseline models with Froude scaling in order to achieve preliminary static stability. Structural dynamic analyses are performed to investigate the performance of the new model using a finite element method approach for the tower and a boundary integral equation (panel) method for the platform. The steady-state response of the system under uniform wind and regular waves is first studied to evaluate the performance of the integrated system. Response amplitude operators (RAOs) are computed in the time domain using white-noise wave excitation; this serves to highlight nonlinear, as well as dynamic characteristics of the system. Finally, selected design load cases (DLCs) and the stochastic dynamic response of the system are studied to assess the global performance for sea states defined by wind fields with turbulence and long-crested irregular waves.
Domaine de référence : EMR
Auteur Liu Jinsong, Thomas Edwin, Manuel Lance, Griffith D. Todd, Ruehl Kelley M., Barone Matthew
Année de parution : 2018.
Mots-clés : design load, offshore wind turbine, response amplitude operator (RAO), stochastic dynamics.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Assessment of Energy Use and Elimination of Co2 Emissions in the Life Cycle of an Offshore Wind Power Plant Farm

Résumé : Power stations in marine locations cause multi-faceted impact on the environment, man and the economy. There are not many studies devoted to modeling energy benefits for CO2 emissions. The paper presents the issues of assessing the efficiency of offshore wind farms, defined as the ratio of benefits to life cycle inputs. The scientific goal was to develop a mathematical model for efficiency in the design, manufacture, use and management of offshore wind power. The papers practical purpose is the experimental designation of the impact of selected post-use management methods, time of use and maritime location, i.e. average annual productivity of wind power plants on the efficiency of energy benefits from greenhouse gas emissions. The mathematical model of the integrated cost-benefit ratio has been developed for energy use assessment, taking into account the benefits generated by electricity production and the life-cycle CO2 emissions based on the LCA analysis using the CML method. Mathematical model validation was performed by determining the value of the indicator for an existing 2 MW offshore wind farm and comparatively for fossil fuel production: lignite, stone, fuel oil and natural gas. Analytical and research work carried out showed that the higher the efficiency index, the higher the value of the indicator. It has been shown that the location of the power station at sea produces more favorable CO2 elimination rates, due to higher productivity compared to in-land wind power plants. A more favorable form of post-consumer management for CO2 has been determined as recycling. It was found that for electricity generated from offshore wind farms, the value of the energy efficiency benefit from CO2 emissions is higher than for fossil fuel energy production.
Domaine de référence : EMR
Auteur Tomporowski Andrzej, Flizikowski Józef, Opielak Marek, Kasner Robert, Kruszelnicka Weronika
Année de parution : 2017.
Mots-clés : CO2 emissions, energy efficiency, offshore wind power plant farms, use of machines.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Wake of horizontal axis tidal-current turbine and its effects on scour / Chen Long

Résumé : Many large scale tidal current turbines (TCTs) have been tested and deployed around the world. It is foreseeable that tidal current will be a vital natural resource in future energy supplies. The wake generated from the TCT amplifies the scour process around the support structure. It causes sediment transport at the seabed and it may result in severe environmental impacts. The study aims to investigate the generated wake and its effects on the scour process around the support structure of the TCT. An analytical wake model is proposed to predict the initial velocity and its lateral distribution downstream of the TCT. The analytical wake model consists of several equations derived from the theoretical works of ship propeller jets. Axial momentum theory is used to predict the minimum velocity at the immediate plane of the wake and followed by recovery equation to determine the minimum velocity at lateral sections along the downstream of the wake. Gaussian distribution is applied to predict the lateral velocity distribution in a wake. The proposed model is also able to predict wake structure under various ambient turbulence conditions (TI= 3%, 5%, 8% and 15%). The proposed wake model is validated by comparing the results with well-accepted experimental measurements. Goodness-of-fit analysis has been conducted by using the estimator of R-square (R2) and Mean Square Error (MSE). The R2 and MSE are in the range of 0.1684–0.9305 and 0.004–0.0331, respectively. A TCT model was incorporated in OpenFOAM to simulate the flow between rotor and seabed due to the fact that the flow is responsible for the sediment transport. The axial component of velocity is the dominating velocity of the flow below the TCT. The maximum axial velocity under the turbine blades is around 1.07 times of the initial incoming flow. The maximum radial and tangential velocity components of the investigated layer are approximately 4.12% and 0.22% of the maximum axial velocity. The acceleration of flow under the rotor changes seabed boundary layer profile. The geometry of the turbine also affects the flow condition. Results showed that the velocity increases with the number of blades. Both the axial and radial velocities were significantly influenced by the number of blades, the tangential velocity was found to be insignificant. A physical model of TCT is placed in a hydraulic flume for scour test. The scour rate of the fabricated model was investigated. The decrease of tip clearance increases the scour depth. The shortest tip clearance results in the fastest and most sediment transport. The maximum scour depth reached approximately 18.5% of rotor diameter. Experimental results indicated that regions susceptible to scour typically persist up to 1.0Dt downstream and up to 0.5Dt to either side of the turbine support centre. The majority of the scour occurred in the first 3.5 hr. The maximum scour depth reaches equilibrium after 24 hr test. The study correlated scour depth of the TCT with the tip clearance. An empirical formula has been proposed to predict the time-dependent scour depth of the pile-supported TCT.
Domaine de référence : EMR
Auteur Chen Long
Année de parution : 2017.
Type de document : Thèse.
Source : University of Malaya
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Development of a technique for inspecting the foundations of offshore wind turbines

Résumé : One design for the foundation of an offshore wind turbine consists of partially overlapping cylinders (the monopile and the transition piece) with a layer of grout between the two. Unfortunately, slippage of the transition piece over the monopile has been observed in many foundations, threatening the long-term stability of the structure. Several utilities have arrested the slippage by welding restraints inside the foundation to transfer the axial loads from the tower to the monopile foundation; however, bending moments are still transferred through the grouted section. If the grout degrades in service then the turbine could still be at risk. An inspection technique is therefore necessary so that foundations can be prioritised for repair. A novel solution is required as conventional NDT techniques either cannot find the conditions of concern or deployment in an offshore environment is hazardous. The approach taken has been to use a swept frequency ultrasonic technique operating below 100 kHz, so that resonances characteristic of the structure and its various fault conditions can be mapped. Laboratory trials supported by mathematical modelling have demonstrated the viability of the approach and a method for delivering the sensor to the regions of interest in a foundation has been developed. Offshore trials have been carried out at an operating wind farm, producing excellent results and a practical inspection system.
Domaine de référence : EMR
Auteur Brett C R, Gunn D A, Dashwood B A J, Holyoake S J, Wilkinson P B
Année de parution : 2018.
Mots-clés : CONCRETE, GROUT, OFFSHORE INFRASTRUCTURE, RESONANCE, ULTRASONIC INTERFERENCE, WIND GENERATION.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Sustainability of the Reanalysis Databases in Predicting the Wind and Wave Power along the European Coasts

Résumé : In the present work, the wind and wave conditions in the European nearshore are assessed considering a total of 118 years of data, covering the time interval from 1900 to 2017. In this context, special attention has been given to the western European coasts that are facing the ocean. In order to do this, the reanalysis data coming from three state-of-the-art databases (ERA Interim, ERA20C, and NCEP) were processed. Furthermore, a more complete picture was provided by also including the satellite measurements coming from the AVISO (Archiving, Validation and Interpretation of Satellite Oceanographic Data) project in the analysis. From this perspective, the distribution of the two marine energy resources was discussed, which throughout energetic maps—and further, on some specific reference sites—were defined at a distance of 50 km from the shore for more detailed analysis and comparison. As expected, the places located in the vicinity of the United Kingdom present more important energy resources, but some other interesting sites were also highlighted. Furthermore, although each dataset is defined by particular features, there is a similar pattern in the identification of the sites’ attractiveness, regardless of the database considered for assessment.
Domaine de référence : EMR
Auteur Onea Florin, Rusu Eugen
Année de parution : 2018.
Mots-clés : coastal areas, European nearshore, reanalysis data, satellite measurements, wind and wave power.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

On Offshore Engineering Rules for Designing Floating Structure of Tidal Current Energy Conversion System

Résumé : Offshore engineering rules have been important part in supporting industrial development of tidal current energy conversion (TCEC) systems. The rules have been considered as guidelines for design of fixed type of TCEC systems, particularly those provided by European Marine Energy Centre (EMEC). However, for floating type of TCEC system, this is not the case. In fact, floating systems have a potential application for particular area of interests, for example in the area with strong currents at the seawater surface or in that with minimal infrastructure for installation support. In future, floating TCEC systems might be installed at the offshore area, even though the current application is commonly at the nearshore. Therefore, it may be beneficial to adopt relevant aspects of the offshore engineering rules for the floating structure design to support TCEC systems. This paper identifies elemental rules which may be suitable for application in the design of this type of floating structure. It includes choice of configurations, dynamic response analysis, material selection, mooring-water depth analyses and removal. This work is an important part of the whole big effort in supporting the development of ocean renewable energy industries.
Domaine de référence : EMR
Auteur Mukhtasor, Junianto Sony, Prastianto Rudi Walujo
Année de parution : 2018.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Improvements in or Relating to Underwater Turbines

Résumé : An underwater frame supporting a plurality of tidal turbines. The frame is tethered to a seabed fixing such that the frame and tidal turbines are positioned downstream of tidal flow. The frame is steerable so as to increase energy capture from said turbines by exposing them to undisturbed tidal flow.
Domaine de référence : EMR
Auteur ARMSTRONG John Richard Carew, TODMAN Michael Torr
Année de parution : 2017.
Type de document : Brevet.
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Experimental Investigations of Breaking Wave Impact Forces on a Monopile Substructure for Offshore Wind Turbines Under Regular Breaking Waves

Résumé : The main objective of the paper is to investigate wave impact forces from breaking waves on a monopile substructure for offshore wind turbine in shallow waters. This study examines the load assessment parameters relevant for breaking wave forces on a vertical circular cylinder subjected to breaking waves. Experiments are conducted in a shallow water flume and the wave generation is based on piston type wave maker. The experiments are performed with a vertical circular cylinder with diameter, D = 0.20m which represents a monopile substructure for offshore wind turbines with regular waves of frequencies around 0.8Hz. The experimental setup consists of a 1/10 slope followed by a horizontal bed portion with a water depth of 0.8m. Plunging breaking waves are generated and free surface elevations are measured at different locations along the wave tank from wave paddle to the cylinder in order to find the breaking characteristics. Wave impact pressures are measured on the cylinder at eight different vertical positions along the height of the cylinder under breaking waves for different environmental conditions. The wave impact pressures and wave surface elevations in the vicinity of the cylinder during the impact for three different wave conditions are presented and discussed.
Domaine de référence : EMR
Auteur Chakkurunni Palliyalil Vipin, Rajamanickam Panneer Selvam, Alagan Chella Mayilvahanan, Govindasamy Vijaya Kumar
Année de parution : 2017.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Acoustic Emission Monitoring : of Offshore Wind Turbine Support Structures for Detection and Localization of Fatigue Crack Growth

Résumé : Offshore wind turbines are used more and more for the production of our electricity. The wind turbines are located in a remote and harsh environment, and are subject to heavy cyclic loading, which may cause fatigue in the support structures. Periodic inspections are required to assess the structural health of the wind turbines. Acoustic Emission Monitoring is the technique of acquiring and processing of the high-frequency sound waves emitted during crack growth. Accurate processing of these signals can lead to detection and localization of fatigue cracks, and further reduction of the need for costly periodic inspections. The factors that determine the coverage area of acoustic emission sensor nodes are source signal strength, attenuation of signal in the medium, and onsite noise level. Together with a cost benefits analysis, this leads to insight into the feasibility of this technique for offshore wind turbines. Investigation of the attenuation is done using a higher-order Spectral Element Method with the input acquired from experiments. The signal that is detected at the sensor has to have sufficiently higher intensity than the surrounding noise. The most severe sources of noise are rain drops hitting the water surrounding the turbine, for which a setup is used in the laboratory, and noise from rotating equipment, for which a measurement has been performed at an on shore wind turbine. The localization accuracy of 5 – 10 percent was shown to be achievable in a laboratory setup. With the coverage area determined, a monitoring strategy for a single wind turbine is proposed, as well as how an acoustic emission monitoring system can be efficiently implemented at a larger scale for a wind farm. It is concluded that acoustic emission monitoring is generally feasible for this application, yet further testing is required in order to decrease the uncertainties and to demonstrate the capabilities to potential operators.
Domaine de référence : EMR
Auteur Lapoutre Gerwin
Année de parution : 2017.
Type de document : Article de revue.
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Numerical and experimental investigation of modal-energy-based damage localization for offshore wind turbine structures

Résumé : Offshore wind turbine structures are prone to deterioration and damage during their service life in harsh marine environment. To explore highly efficient and robust damage detection methods for offshore wind turbine structures, three well-known modal strain energy indices are reviewed first and then a new index named total modal energy method is proposed. The innovation of the new index is the simultaneous use of modal strain energy and modal kinetic energy. To investigate the feasibility and robustness of the four modal-energy-based methods, numerical and experimental studies are conducted on a tripod-type offshore wind turbine structure with simulated and measured data. It is indicated that all the four modal-energy-based methods work well with limited incomplete modal data, especially for the single-damage cases. While for the cases of multiple damage locations, the new total modal energy index significantly outperforms the traditional modal strain energy indices. Moreover, high robustness is shown for the indices, when the measured mode shapes of undamaged and damaged structures are polluted with the same noise level. However, when their noise levels have some difference, two of the modal strain energy indices turn invalid, but the new total modal energy index still shows stronger robustness. As frequencies are also used in the total modal energy index, its robustness to the noise in modal frequencies is also studied. It is shown that the results are slightly affected by the measurement noise in modal frequencies. Besides, the influence of finite element modeling errors is also investigated with both simulated and experimental data. Results show that all the four modal-energy-based methods are all very stable and insensitive to certain modeling errors. So, finite element model updating is not necessary in the test structure herein.
Domaine de référence : EMR
Auteur Li Yingchao, Zhang Min, Yang Wenlong
Année de parution : 2018.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Identification and control of a river-current-turbine generator _ application to a full-scale prototype

Résumé : This paper reports on the operation assessment of an electrical power generation system based upon cross-flow water turbines. The specific power take-off system has been tested in real-world conditions in a variety of scenarios and the experimental results have confirmed previous modeling assessments. Dynamical proprieties have been precisely identified and stable system operation over the entire operating range has been achieved. Steady-state characterization in terms of power coefficient has also been done, allowing the assessment of power generation system global efficiency and enabling the building of more precise models to be used in further simulations and assessments for power grid integration. Maximum power point tracking and other specific operation regimes such as angular position synchronization have also been validated.
Domaine de référence : EMR
Auteur Hauck M., Rumeau A., Bratcu A. I., Bacha S., Munteanu I., roye d
Année de parution : 2017.
Mots-clés : Generators, Hydraulic turbines, Maximum Power Point Tracking, microhydro power, performance evaluation, Poles and towers, power generation control, Prototypes, Torque.
Type de document : Article de revue.
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Tidal turbine with variable flow characteristics

Résumé : A tidal turbine and generator assembly having a turbine with rotor blades 16 disposed around a rotor axis C and mounted on a tower 14, wherein a pair of aerofoils 22 is mounted upstream of the blades either side of the rotor 13, each aerofoil mounted on a rotatable support 26 and able to turn around a vertical axis Y while its chord line remains orthogonal thereto. Simultaneous and symmetrical swivel of the aerofoils can concentrate or diffuse the water flow incident on the turbine and thereby control rotor speed and power and also protect the turbine from overload in high tidal flows. The aerofoils effectively provide an inlet funnel and are preferably arc-shaped, curved around the rotor axis. They are preferably mounted in line with the yaw axis Z of the turbine, which is preferably weight balanced on axis Z and yaws with respect to the tower on a pintle 12. The turbine blades are preferably retractable, so that collision with large, heavy objects coming their way and detected by a sonar 34 may be avoided. Finally the rotor may have a buoyant part to counteract the weight of generator 15 and turbine blades 16.
Domaine de référence : EMR
Auteur Richard Ayre
Année de parution : 2017.
Type de document : Brevet.
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An innovative configuration for new marine current turbine

Résumé : Researchers have shown growing interest in the development of traditional Savonius turbine due to their numerous benefits such as structural simplicity, self-start ability, relatively low operating speed, bi-directional rotational ability and lower environmental impact. However, Savonius turbines exhibits lower efficiency as compared to other similar marine current turbines. This paper proposes a novel design concept for the Savonius turbine. In addition, this work investigates flow and pressure distribution around the buckets of novel rotor with a two-dimensional unsteady numerical model. The proposed marine current turbine with novel design is named as Reza Turbine. Numerical model employed the Dynamic Mesh Method (DMM) for modelling mesh movement around the blades of rotor for different position with respect to computational domain. Developed numerical model solves the unsteady Reynolds averaged Navier-Stokes equations by using SIMPLE algorithm. In addition, we conducted an experiment in a low speed wind tunnel to obtain important performance parameters namely torque, power and performance for the proposed turbine. A set of flow speed were used as inlet boundary condition for both numerical and experimental model. A comparison between numerical and experimental results shows that the SST k-ω turbulence model gives satisfactory results for the developed novel turbine. The developed ReT is showed 52% improvement in efficiency as compared conventional Savonious turbine. Since the peak of power coefficient obtained was 0.321 for ReT, while 0.21 was reported for conventional Savonius turbine.
Domaine de référence : EMR
Auteur Hassanzadeh Reza, Yaakob Omar bin, Ahmed Yasser M.
Année de parution : 2017.
Mots-clés : Dynamic mesh, Flexible and foldable bucket, Marine current turbine, Numerical simulation.
Type de document : Article de revue.
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Current status and future of ocean energy sources : A global review

Résumé : In this study, detailed information about the fundamentals, energy and power potentials, devices, technologies, installed capacities, annual generation, and future of ocean energy sources: tidal, wave, temperature and salinity gradients are given as an up to date global review. Detailed analysis showed that aggregate global annual potential of different ocean energy sources is significantly greater than our global annual electricity demand. As a result, many countries around the globe aim to utilise ocean energy sources for power generation. However, this is currently not possible on a large scale because most of the ocean energy technologies are still under development and there are many economic, technical and environmental problems to be solved. Therefore, the research and development in ocean energy engineering should be fostered by governments and private sector around the globe so that we can use these reliable and clean renewable energy sources for supplying our increasing global electricity demand. Finally, this study could offer some assistance to the academia and industry for the utilisation of different ocean energy sources for achieving a sustainable future.
Domaine de référence : EMR
Auteur Melikoglu Mehmet
Année de parution : 2018.
Mots-clés : Energy, Ocean, Osmotic, Thermal, Tidal, Wave.
Type de document : Article de revue.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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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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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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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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
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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.
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Plus de références EMR


• Biocorrosion icone-flux-rss

Using Thermodynamics to Predict the Outcomes of Nitrate-Based Oil Reservoir Souring Control Interventions

Résumé : Souring is the undesirable production of hydrogen sulfide (H2S) in oil reservoirs by sulfate-reducing bacteria (SRB). Souring is a common problem during secondary oil recovery via water flooding, especially when seawater with its high sulfate concentration is introduced. Nitrate injection into these oil reservoirs can prevent and remediate souring by stimulating nitrate-reducing bacteria (NRB). Two conceptually different mechanisms for NRB-facilitated souring control have been proposed: nitrate-sulfate competition for electron donors (oil-derived organics or H2) and nitrate driven sulfide oxidation. Thermodynamics can facilitate predictions about which nitrate-driven mechanism is most likely to occur in different scenarios. From a thermodynamic perspective the question “Which reaction yields more energy, nitrate driven oxidation of sulfide or nitrate driven oxidation of organic compounds?” can be rephrased as: “Is acetate driven sulfate reduction to sulfide exergonic or endergonic?” Our analysis indicates that under conditions encountered in oil fields, sulfate driven oxidation of acetate (or other SRB organic electron donors) is always more favorable than sulfide oxidation to sulfate. That predicts that organotrophic NRB that oxidize acetate would outcompete lithotrophic NRB that oxidize sulfide. However, sulfide oxidation to elemental sulfur is different. At low acetate HS− oxidation is more favorable than acetate oxidation. Incomplete oxidation of sulfide to S0 is likely to occur when nitrate levels are low, and is favored by low temperatures; conditions that can be encountered at oil field above-ground facilities where intermediate sulfur compounds like S0 may cause corrosion. These findings have implications for reservoir management strategies and for assessing the success and progress of nitrate-based souring control strategies and the attendant risks of corrosion associated with souring and nitrate injection.
Domaine de référence : Biocorrosion
Auteur Dolfing Jan, Hubert Casey R. J.
Année de parution : 2017.
Type de document : Article de revue.
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Mise en place d’un bioréacteur pour l’évaluation de la biocorrosion de matériaux en fonte

Résumé : La corrosion influencée par les microorganismes (MIC) est un phénomène qui touche une majorité d’industries utilisant des matériaux en fer en contact avec une phase aqueuse susceptible de contenir des bactéries. C’est le cas notamment des canalisations en fonte ductile enfouies dans les sols. Afin de comprendre et de pouvoir anticiper ces phénomènes de corrosion, nous avons cherché dans un premier temps à reproduire le phénomène de la MIC au laboratoire, à l’aide de plusieurs souches pures ; de cocultures et d’environnements complexes (sols, boues activées), susceptibles de provoquer une corrosion significative. Dans un second temps, nous avons conçu un réacteur permettant de quantifier « électrochimiquement » une biocorrosion. Les résultats soulèvent l’importance de l’utilisation de contrôles abiotiques pour discriminer une MIC d’une corrosion chimique. Par ailleurs, les co-cultures entrainent une corrosion plus importante que les cultures en souche pure. Cependant, certains groupes métaboliques semblent capables de ralentir la corrosion. Le réacteur électrochimique pourra à terme être utilisé pour évaluer l’intensité de la corrosion selon les inocula utilisés
Domaine de référence : Biocorrosion
Auteur Didierjean Laura
Année de parution : 2017.
Type de document : Thèse.
Source : Université de Lorraine
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Control of corrosive bacterial community by bronopol in industrial water system

Résumé : Ten aerobic corrosive bacterial strains were isolated from a cooling tower water system (CWS) which were identified based on the biochemical characterization and 16S rRNA gene sequencing. Out of them, dominant corrosion-causing bacteria, namely, Bacillus thuringiensis EN2, Terribacillus aidingensis EN3, and Bacillus oleronius EN9, were selected for biocorrosion studies on mild steel 1010 (MS) in a CWS. The biocorrosion behaviour of EN2, EN3, and EN9 strains was studied using immersion test (weight loss method), electrochemical analysis, and surface analysis. To address the corrosion problems, an anti-corrosive study using a biocide, bronopol was also demonstrated. Scanning electron microscopy and Fourier-transform infrared spectroscopy analyses of the MS coupons with biofilm developed after exposure to CWS confirmed the accumulation of extracellular polymeric substances and revealed that biofilms was formed as microcolonies, which subsequently cause pitting corrosion. In contrast, the biocide system, no pitting type of corrosion, was observed and weight loss was reduced about 32 ± 2 mg over biotic system (286 ± 2 mg). FTIR results confirmed the adsorption of bronopol on the MS metal surface as protective layer (co-ordination of NH2–Fe3+) to prevent the biofilm formation and inhibit the corrosive chemical compounds and thus led to reduction of corrosion rate (10 ± 1 mm/year). Overall, the results from WL, EIS, SEM, XRD, and FTIR concluded that bronopol was identified as effective biocide and corrosion inhibitor which controls the both chemical and biocorrosion of MS in CWS.Graphical Abstract Open image in new window
Domaine de référence : Biocorrosion
Auteur Narenkumar Jayaraman, Ramesh Nachimuthu, Rajasekar Aruliah
Année de parution : 2018.
Type de document : Article de revue.
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Microbial community structure of a low sulfate oil producing facility indicate dominance of oil degrading/nitrate reducing bacteria and Methanogens

Résumé : Analysis of microbial community structure of a low sulfate oil producing facility in Nigeria using 16S rRNA gene sequencing technique revealed dominance of oil degrading and nitrate reducing bacteria and methanogenic archaea in produced waters and oil samples namely, Marinobacter (37%), Azovibrio (21%), Thauera (10–28%), and Methanolobus (22%). On the contrary, the associated oil pipeline samples revealed massive dominance of potentially corrosive Methanolobus (60%) and Methanobacterium (25-27%). Further experimentation shows that the methanogens implicated in oil pipelines are corrosive moderate halophile that utilizes H2/CO2 and methanol as substrates. More emphasis should therefore be on methanogenic archaea as opposed to sulfate reducing bacteria (SRBs) during mitigation plans for microbially induced corrosion (MIC) in a low sulfate oil producing facility.
Domaine de référence : Biocorrosion
Auteur Okoro Chuma Conlette, Amund Olukayode O.
Année de parution : 2018.
Mots-clés : low sulfate oil facility, methanogens, MIC, nitrate reducing bacteria, oil degrading bacteria.
Type de document : Article de revue.
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Characterization of hydrocarbon degrading bacteria isolated from Indian crude oil reservoir and their influence on biocorrosion of carbon steel API 5LX

Résumé : The role of biosurfactants producing hydrocarbon-degrading bacteria (HDB) on 33 biodegradation and bio-corrosion was evaluated. Biodegradation efficiency (BE) of 34 Streptomyces parvus B7 was found to be 82% when compared to other bacteria. Increased 35 production of biosurfactants directly influences the rate of crude oil BE. Corrosion of carbon 36 steel was found to be more severe in mixed bacterial consortia (1.493 ± 0.015 mm/y). X-ray 37 diffraction confirmed the presence of high intensity of ferric oxide (Fe2O3), iron oxide 38 (Fe3O4), manganese oxide (Mn3O4), and manganese dioxide (MnO2) in corrosion product of 39 mixed bacterial system. Biofilm formation was assist to pit formation on the carbon steel 40 surface and it was evidenced from the atomic force microscopy (AFM) and scanning electron 41 microscopy (SEM) analysis. Corrosion current was increased in the presence of mixed 42 consortia 1.6 ± 0.2 × 10-3 A/cm-2, compared to abiotic control 1.2 ± 0.15 × 10-4 A/cm-2, this 43 values were well supported with charge transfer values and these observations confirmed that 44 mixed bacterial consortia play key role in the corrosion of carbon steel. This is the first report 45 to show degradation of crude oil by Streptomyces parvus B7 and its effects on the corrosion 46 of carbon steel in oil reservoir.
Domaine de référence : Biocorrosion
Auteur Parthipan P. (Punniyakotti), P (Punniyakotti) Elumalai, Peng) Ting Y. (Yen, Rahman P. K. S. M. (Pattanathu), Rajasekar A. (Aruliah)
Année de parution : 2018.
Type de document : Article de revue.
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Methods to Determine Conditions of a Hydrocarbon Reservoir

Résumé : A method of identifying in situ conditions of a hydrocarbon reservoir is disclosed. The method comprises, obtaining a sample from an area of interest, such as a sediment sample or water column sample near a hydrocarbon seep; analyzing the sample to detect lipid, protein, and/or nucleic acid signatures that are indicative of the Thermotogales order; identifying the relative abundance of the different genera and/or species of the Thermotogales present in the sample to generate a taxonomy signature of the sample; and then using the taxonomy signature to determine conditions, such as temperature, of the hydrocarbon reservoir.
Domaine de référence : Biocorrosion
Auteur Summers Zarath M., N'guessan Lucie A., Regberg Aaron B.
Année de parution : 2018.
Type de document : Brevet.
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Elucidating the stimulatory and inhibitory effects of dissolved sulfide on sulfur-oxidizing bacteria (SOB) driven autotrophic denitrification

Résumé : Autotrophic denitrification has been widely studied for odor mitigation, corrosion control and nitrogen removal in recent years. This paper examines the response of sulfur-oxidizing bacteria (SOB) driven autotrophic denitrification under short-term stress of dissolved sulfide. A series of batch tests were conducted to investigate the effect of different sulfide concentrations (0–1600 mg-total dissolved sulfide (TDS)/L) on autotrophic denitrification and sulfide oxidation by SOB-enriched sludge. Our results show that autotrophic denitrification (NO3− to N2) was stimulated up to 200 mg-TDS/L with a maximum denitrification rate of 9.4 mg-N/g-volatile suspended solids (VSS)/h, and the nitrite reduction was a rate limiting step. When sulfide concentration was higher than 200 mg-TDS/L, it inhibited nitrate reductase, and nitrate reduction became the rate limiting step according to Edwards and Aiba inhibition models. Sulfide oxidation, however, was not inhibited and the maximum rate of 100.3 mg-TDS/g-VSS/h was obtained at sulfide concentration of 1000 mg-TDS/L. It is important to point out that the transient inhibition on autotrophic denitrification caused by high sulfide stress was resilient and non-lethal with no significant changes in cell viability even under sulfide concentration of 1000 mg-TDS/L. This study reveals the stimulatory and inhibitory effects of dissolved sulfide on SOB driven autotrophic denitrification and its possible underlying mechanism with discussion on engineering implications.
Domaine de référence : Biocorrosion
Auteur Lu Hui, Huang Haiqin, Yang Weiming, Mackey Hamish Robert, Khanal Samir Kumar, Wu Di, Chen Guang-Hao
Année de parution : 0.
Mots-clés : Autotrophic denitrification, Biological sulfide oxidation, Dissolved sulfide, Sulfur-oxidizing bacteria (SOB).
Type de document : Article de revue.
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Bacterial iron reduction and biogenic mineral formation for the stabilisation of corroded iron objects

Résumé : Exploiting bacterial metabolism for the stabilisation of corroded iron artefacts is a promising alternative to conventional conservation-restoration methods. Bacterial iron reduction coupled to biogenic mineral formation has been shown to promote the conversion of reactive into stable corrosion products that are integrated into the natural corrosion layer of the object. However, in order to stabilise iron corrosion, the formation of specific biogenic minerals is essential. In this study, we used the facultative anaerobe Shewanella loihica for the production of stable biogenic iron minerals under controlled chemical conditions. The biogenic formation of crystalline iron phosphates was observed after iron reduction in a solution containing Fe(III) citrate. When the same biological treatment was applied on corroded iron plates, a layer composed of iron phosphates and iron carbonates was formed. Surface and cross-section analyses demonstrated that these two stable corrosion products replaced 81% of the reactive corrosion layer after two weeks of treatment. Such results demonstrate the potential of a biological treatment in the development of a stabilisation method to preserve corroded iron objects.
Domaine de référence : Biocorrosion
Auteur Kooli Wafa M., Comensoli Lucrezia, Maillard Julien, Albini Monica, Gelb Arnaud, Junier Pilar, Joseph Edith
Année de parution : 2018.
Type de document : Article de revue.
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Electrochemical frequency modulation (EFM) technique : Theory and recent practical applications in corrosion research

Résumé : Determining instantaneous corrosion rate and corrosion mechanism of metals, while ensuring the most minimal damage of the sample, is an important ingredient for an electrochemical technique. In recent times, electrochemical frequency modulation (EFM) has attracted the attention of corrosion researchers as a promising technique with high sensitivity due to the measurement of corrosion parameters at harmonics and intermodulations of input frequencies, as well as high accuracy due to the inherent calculation of causality factors. Comparison of data obtained from EFM with results from conventional electrochemical techniques for corrosion analysis has, therefore, become a common trend. In the following paper, we review the EFM technique and its propensity to become an electrochemical technique of choice for corrosion research. The fundamental principles, modes of data collection as well as a critical comparison between EFM technique and contemporary electrochemical techniques are detailed. Recent application of EFM for the evaluation of corrosion inhibitors, analyses of CO2 corrosion and the evaluation of microbially–induced corrosion are highlighted.
Domaine de référence : Biocorrosion
Auteur Obot I. B., Onyeachu Ikenna B.
Année de parution : 2018.
Mots-clés : CO corrosion, Corrosion inhibition, Electrochemical frequency modulation (EFM), Electrochemistry, Microbiologically influenced corrosion (MIC).
Type de document : Article de revue.
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Pipeline steel with resistance to microbiological corrosion

Résumé : The invention aims to provide a pipeline steel with resistance to microbiological corrosion on the premise of guaranteeing the advantages of conventional pipeline steel so as to substantially reduce the possibility of microbiological corrosion from material source. The pipeline steel provided by the invention comprises the following chemical components by weight: 0.020 to 0.030% of C, 0.10 to 0.15% of Si, 0.9 to 1.1% of Mn, 1.0 to 2.0% of Cu, 0.30 to 0.35% of Ni, 0.30 to 0.35% of Mo, 0.30 to 0.35% of Cr, 0.045 to 0.055% of Nb, 0.015 to 0.025% of V, no more than 0.0015% of S and no more than 0.0050% of P, with the balance being Fe. The elemental Cu is added into the pipeline steel, so after aging treatment, the pipeline steel has greatly improved strength and excellent microbiological corrosion resistance.
Domaine de référence : Biocorrosion
Auteur 单以银, 杨柯, 史显波, 严伟, 王威, 杨振国, 徐大可
Année de parution : 2017.
Type de document : Brevet.
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Method for Selective Treatment of Microbiologically Influenced Corrosion (mic) of Metal Surfaces

Résumé : Provided is a multi-phase process for conditionally treating MIC by evaluating whether MIC-correlating conditions exist, the degree of MIC, if present, and then applying a concomitant MIC-mitigating treatment which is adjusted in its degree of aggressiveness in proportion to MIC severity. The disclosed methodology allows, in part, for the continuous or periodic monitoring and assessment of MIC risk in petroleum-based equipment (e.g., pipeline) and the administering of a treatment that corresponds to the level of severity of the MIC resulting in a more fine-tuned, localized, and cost-effective treatment.
Domaine de référence : Biocorrosion
Auteur Pilloni Giovanni, Enning Dennis R.
Année de parution : 2017.
Type de document : Brevet.
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Fire Protection Systems Having Reduced Corrosion

Résumé : A fire protection system comprising at least one sprinkler, a source of pressurized water, a piping network connecting at least one sprinkler to the source of pressurized water, and a nitrogen generator coupled to the sprinkler system. The nitrogen generator may be a nitrogen membrane system or a nitrogen pressure swing adsorption system. The present systems and methods reduce or nearly eliminate corrosion that typically affects conventional fire protection systems, such as caused by oxygen and microbial systems, which can deteriorate or compromise function. Initial, repeated, or continuous displacement of oxygen with nitrogen in the fire protection system significantly reduces or eliminates corrosion.
Domaine de référence : Biocorrosion
Auteur Burkhart David, Kochelek Jeffrey, Jones Kenneth, Holt Thorstein
Année de parution : 2017.
Type de document : Brevet.
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Altering Microbial Populations & Modifying Microbiota

Résumé : The invention relates to methods, uses, systems, arrays, engineered nucleotide sequences and vectors for inhibiting bacterial population growth or for altering the relative ratio of sub-populations of first and second bacteria in a mixed population of bacteria. The invention is particularly useful, for example, for treatment of microbes such as for environmental, medical, food and beverage use. The invention relates inter alia to methods of controlling microbiologically influenced corrosion (MIC) or biofouling of a substrate or fluid in an industrial or domestic system.
Domaine de référence : Biocorrosion
Auteur CLUBE Jasper, SOMMER Morten, GRØNDAHL Christian, VAN DER HELM Eric, VAZQUEZ-URIBE Ruben
Année de parution : 2017.
Type de document : Brevet.
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Anticorrosive Coating and Method of Its Production

Résumé : FIELD: chemistry.SUBSTANCE: invention relates to the protective coating that is applied as corrosion protection coatings for corrosive bases, particularly corrosive metals, alloys, and other materials, in particular steel, used as a primer coating for causing further multi-layer porous coatings or as a surface layer, as well as to the method in which it is received and the application on the coated base for the corrosion protection, in particular, for the use against microbiologically induced corrosion (MIC). An anticorrosion coating has a thickness of at least 50 μm. The anticorrosion coating includes a high-density protective coating of the base subject to corrosion, containing the pre-condensed precursors of alkoxysilane forming a coating. The molecules of the pre-condensed precursors of alkoxysilane forming a coating are constructed by linear and short-chain ones from the monomer units from the group of precursors of alkoxysilane. Moreover, the molecules of the pre-condensed precursor of alkoxysilane forming a coating are cross-linked. Obtaining anticorrosive coating involves preparing the anticorrosive composition, in which at least one precursor of alkoxysilane forming a coating without a solvent and additives by adding water in a molar ratio of 3:1 to 1:1 under acidic pH conditions, at a temperature in the range of 0°C to 10°C is converted into a pre-condensed precursor of alkoxysilane forming a coating. Further, the anticorrosive composition is applied to the substrate and cured to produce a high-density protective coating.EFFECT: production of high-density anticorrosion coating, suitable for corrosion protection, including for protection against microbiological corrosion of various materials.25 cl, 13 dwg, 14 ex
Domaine de référence : Biocorrosion
Auteur КРОКЕ Эдвин, ПРАЙФЕР Штефан
Année de parution : 2017.
Type de document : Brevet.
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Analysis of the Prevention of Biocorrosion Caused by Desulfovibrio alaskensis G20

Résumé : Desulfovibrio alaskensis G20 and other sulfate-reducing bacteria cause significant damage to metal pipelines and other infrastructure through a metabolic pathway that releases toxic hydrogen sulfide into their surroundings. The biocorrosion that results from the release of hydrogen sulfide creates significant economic burden, and can pose health risks for those exposed to this chemical. They are commonly present in the form of biofilms, an extracellular matrix composed of bacterial cells, polysaccharides, proteins, nucleic acids, and other materials. These biofilms are difficult to remove, and they provide protection to the bacteria within from anti-bacterial treatments. Desulfovibrio alaskensis G20 is a strain derived from a wild-type bacterium collected from an oil well corrosion site and is a model organism for understanding biofilm formation of sulfate-reducing bacteria and how these biofilms can be prevented or inhibited by techniques such as cerium oxide nanoparticle coating. To this end, samples of Desulfovibrio alaskensis G20 were grown anaerobically in 24-well and 96-well plates, and the resultant biofilm growth was measured through spectrophotometry. Several different environmental parameters were tested, including temperature, electron donor molecules, basal and enriched growth media, and oxidative stress, revealing several affinities for production of biofilm growth.
Domaine de référence : Biocorrosion
Auteur Boring Michael
Année de parution : 2017.
Type de document : Thèse.
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Microbiologically Influenced Corrosion in Aluminium Alloys 7075 and 2024

Résumé : Aluminum and its alloys are central materials for the aircraft industry. Aluminum alloys (AA) 7075 and 2024 are widely used both in the structures and in brittle sections of the airplanes. The presence of the alloying elements in these metals makes them susceptible to localized corrosion at the same time vulnerable to bacterial attachment. A great number of reports on aircraft deterioration are related to microbial growth by contamination inside fuel storage tanks and aircraft wing tanks; this phenomenon is known as microbiologically influenced corrosion (MIC). As expected, corrosion and biocorrosion increase maintenance costs and time of the aircraft in the hangar. Therefore, the growing interest is to shed light on these issues and develop future inhibition methods. In this chapter, we will give an overview of microbiologically influenced corrosion associated with AA 2024 and 7075 by consortia and bacteria. Three mechanisms of biocorrosion in aluminium alloys have been described. In addition, some alternatives methods to battle the effect of biocorrosion will be shown, these methods are based on green compound which blocking of attached of bacteria and promote the detachment of biofilm, being these a tendency of the last innovation way to inhibit this kind of phenomenon.
Domaine de référence : Biocorrosion
Auteur Nelson Vejar V., Maria Orrego T., Mamiè Sancy V., C. Maritza Paez
Année de parution : 2017.
Type de document : Article de revue.
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Corrosion of antibacterial Cu-bearing 316L stainless steels in the presence of sulfate reducing bacteria

Résumé : Corrosion of two types of antibacterial Cu-bearing 316L stainless steel was investigated in a medium containing sulfate reducing bacteria (SRB) by various surface characterization and electrochemical measurements. The addition of Cu does not improve the resistance of 316L stainless steel to microbiologically influenced corrosion. The anticorrosion performance of 316L-Cu-A is better than 316L-Cu-B, which is believed to be associated with the addition of elements La and Ce, rather than Cu, in the steel. The Cu ions react with sulfides produced by SRB to produce copper sulfide on the steel surface, increasing corrosion of the Cu-bearing stainless steels.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Xu Dake, Yang Ke, Liu Hongfang, Cheng Y. Frank
Année de parution : 2017.
Mots-clés : A. Stainless steel, B. EIS, B. SEM, B. XPS, C. Microbiological corrosion.
Type de document : Article de revue.
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Variations of Microenvironments with and without SRB for Steel Q 235 under a Simulated Disbonded Coating

Résumé : Distributions of potential and current and variations of crevice environments are studied in a crevice under a simulated disbonded coating in soil extract solutions (SES) with and without sulfate-reducing bacteria (SRB). Results show that forming of the crevice blocks the penetration of cathodic currents in the crevice and weakens the cathodic polarization of the steel Q 235. The cathodic currents in the presence of SRB are nearly three times more than those without SRB at the same cathodic protective potential, which indicates that SRB increases the energy consumption of the cathodic protection systems. SRB leads to basification of the solution in the crevice. The forming of inner electric field enhances the anionic migration into the crevice. The forming of the reversed potential increases the cathodic current.
Domaine de référence : Biocorrosion
Auteur Xu Jin, Sun Cheng, Yan Maocheng, Wang Fuhui
Année de parution : 2013.
Type de document : Article de revue.
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Poly(4-vinylaniline)-Polyaniline Bilayer-Modified Stainless Steels for the Mitigation of Biocorrosion by Sulfate-Reducing Bacteria (SRB) in Seawater

Résumé : A novel strategy by combination of surface-initiated atom transfer radical polymerization (ATRP) and in situ chemical oxidative graft polymerization was employed to tether stainless steel (SS) with poly(4-vinylaniline)-polyaniline (PVAn-PANI) bilayer coatings for mitigating biocorrosion by sulfate-reducing bacteria (SRB) in seawater. A trichlorosilane coupling agent was first immobilized on the SS surfaces to provide sulfonyl halide groups for surface-initiated ATRP of 4-VAn. A subsequent grafting of PANI onto the PVAn-grafted surface was accomplished by in situ chemical oxidative graft polymerization of aniline. The PVAn-PANI bilayer coatings were finally quaternized by hexylbromide to generate biocidal functionality. The so-synthesized SS surface was found to significantly reduce bacterial adhesion and biofilm formation. Electrochemical results revealed that the PVAn-PANI modified SS surface exhibited high resistance to biocorrosion by SRB. With the inherent anticorrosion capability and antibacterial properties of quaternized PVAn-PANI bilayers, the functionalized SS substrates are potentially useful to steel-based equipment under harsh marine environments.
Domaine de référence : Biocorrosion
Auteur Yuan Shaojun, Tang Shengwei, Lv Li, Liang Bin, Choong Cleo, Pehkonen Simo Olavi
Année de parution : 2012.
Type de document : Article de revue.
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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.
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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.
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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.
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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 : 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.
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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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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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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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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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Eco-friendly design of superhydrophobic nano-magnetite/silicone composites for marine foul-release paints

Résumé : Advances in nanomaterials science are associated with developments fabrication methods in terms of energy saving, environment friendliness, and low cost. Self-cleaning nanocoatings with fouling release (FR) mechanism have been extensively investigated because of their non-stick, non-leachant, ecological, and economic advantages. Herein, we successfully modeled a series of self-cleaning technologies by using elastiometric siloxane polymer/nano-magnetite composites. The nanocomposite systems are dynamic non-stick surfaces and deter any fouling attachment through physical anti-adhesion. A series of superhydrophobic nanocomposites were synthesized through solution casting using different concentrations of nano-magnetite fillers. The fillers Exhibit 10–20nm particle diameter range and spherical shape facet mainly with the {311} crystal lattice plane. The composites were dispersed in linear ἀ,ὼ-dihydroxy polydimethylsiloxane (PDMS). Wettability characteristics, such as hydrophobicity, roughness, and free energy, were investigated by water contact angle analysis, field emission scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy to evaluate self-cleaning and FR features. The nanocomposites were also subjected to various tests on surface adhesion and mechanical properties, such as tensile modulus, impact, T-bending, crosscut, and abrasion resistance. The anticorrosive features were investigated through salt spray test in 5wt.% NaCl. Microfoulants of diatoms and bacterial progenies were selected and used to assess the anti-adhesion performance of the tailored nanosurfaces. The biological tests in laboratory was confirmed with a 3-month natural seawater field trial which indicated excellent inhibition of diatoms and bacterial growth and approved superior antifouling FR potential of the polymer/nano-magnetite (0.5%) composite hybrid coatings. This study provides insights into how structure–property relationship can enhance biological antiadhesion and FR performance. The uniform distribution of the nano-magnetite particles improved their water repellency, smoothness, and biological inertness. The particles also exhibited high static contact angle of about 153°±2° and low surface free energy with the lotus effect. The bulk properties and durability as well as anticorrosive properties were improved. The PDMS/magnetite nanomodels possess numerous advantages, such as simplicity, non-toxicity, environmental sustainability, commercial feasibility, low fuel consumption, and desirable self-cleaning surfaces with durability characteristics.
Domaine de référence : Antifouling
Auteur Selim Mohamed S., Elmarakbi Ahmed, Azzam Ahmed M., Shenashen Mohamed A., EL-Saeed Ashraf M., El-Safty Sherif A.
Année de parution : 2018.
Mots-clés : Bacterial progenies, Fouling release, Good-distribution, Lotus effect, Nano-magnetite fillers, Nanocomposites.
Type de document : Article de revue.
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A MARINE CABLE DEVICE ADAPTED FOR THE PREVENTION OF FOULING

Résumé : The present invention provides a marine cable device configured for preventing or reducing biofouling along its exterior surface, which during use is at least temporarily exposed to water. The marine cable device according to the present invention comprises at least one light source configured to generate an anti-fouling light and at least one optical medium configured to receive at least part of the anti-fouling light. The optical medium comprises at least one emission surface configured to provide at least part of said anti-fouling light on at least part of said exterior surface.
Domaine de référence : Antifouling
Auteur Hietbrink Roelant Boudewijn, Salters Bart Andre
Année de parution : 2017.
Type de document : Brevet.
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Antimacrofouling Efficacy of Innovative Inorganic Nanomaterials Loaded with Booster Biocides

Résumé : The application of nano-structured compounds has been increasing rapidly in recent years, in several fields. The use of engineered nano-materials as carriers of antifouling compounds is just beginning and already reveals clear advantages compared to bulk active compounds, such as slowed and controlled release, novel functionality, and high loading capacity. This present study assesses the antifouling efficacy of two nanostructured materials, spherical mesoporous silica nanocapsules (SiNC) and Zn-Al layered double hydroxides (LDH), loaded with two commercial biocides, zinc prithione (ZnPT) and copper pyrithione (CuPT). The study used adult mussels from three geographical regions, the Atlantic Ocean, Mediterranean Sea, and the Red Sea, to examine the efficacy of the innovative compounds. The efficacy of these compounds on larvae of the bryozoan Bugula neritina from the Mediterranean Sea and the Red Sea was also examined. The results of this study demonstrated the environmentally friendly properties of unloaded LDH against the two-model systems, adult mussels or bryozoan larvae. ZnPT entrapped in LDH demonstrated the most effective antifouling compound against the two model systems. A comparison of the impact of the two compounds on macrofouling organisms from the different marine habitats examined in this study indicates a distinction associated with the organisms’ different ecosystems. The Red Sea mussels and bryozoans, representing a tropical marine ecosystem, yielded the highest efficacy values among tested Atlantic Ocean and Mediterranean Sea mussels and bryozoans.
Domaine de référence : Antifouling
Auteur Gutner-Hoch Eldad, Martins Roberto, Oliveira Tania, Maia Frederico, Soares Amadeu M. V. M., Loureiro Susana, Piller Chen, Preiss Iris, Weis Michal, Larroze Severine B., Teixeira Tania, Tedim João, Benayahu Yehuda
Année de parution : 2018.
Mots-clés : antifouling nano-structured compounds, fouling, layered double hidroxides, pyrithione, silica mesoporous nanocapsules.
Type de document : Article de revue.
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Application of polyurethane/gamma-irradiated carbon nanotubes composites as antifouling coat

Résumé : The aim of this study is to avoid or reduce the risks of biofouling of ship hulls, using polyurethane/γ-irradiated functionalized multiwall carbon nanotubes (PU/FMWCNT) nanocomposites as a coating for wood. These nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR) measurements, transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM), and hardness, adhesion, and bending of the coated samples were examined. The antifouling ability of PU/γ-irradiated FMWCNTs was studied by using an algae test. FTIR proved the presence of COOH group on the surface of MWCNT, while the FESEM results showed good dispersion of FMWCNT in polyurethane matrix. Mechanical properties of the coated wooden samples were improved; the samples showed good hardness and very good adhesion, and reasonable flexural modulus. The antifouling property of the coatings showed that 0.1 and 0.2 wt% FMWCNTs immobilized on polyurethane composite and irradiated for 100 kGy, were the most efficient antifouling coat when immersed in Chlorella vulgaris microalgae. POLYM. COMPOS., 2018. © 2018 Society of Plastics Engineers
Domaine de référence : Antifouling
Auteur Eyssa Hanan M., Abulyazied Dalia E., Abo-State Mervat A. M.
Année de parution : 2018.
Type de document : Article de revue.
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Removal and/or prevention of limescale in plumbing tubes by a radio-frequency alternating electric field inductance device

Résumé : Fouling problems due to limescale formation are of major concern to many industries. Deterioration of heat transfer equipment performance and substantial increase of pressure drop across piping systems comprise the main problems, resulting in high machinery-maintenance cost and decreased productivity. Limescale removal techniques, like scraping, hydro-blasting, and the use of aggressive chemicals, shorten the life of pipes and machinery. Furthermore, limescale prevention techniques in industrial scale, like ion-exchange or reverse osmosis, require expensive equipment and heavy maintenance. In this paper, an electronic antifouling device is presented which, not only prevents limescale formation, but also removes existing scale in plumbing tubes, at insignificant energy consumption. Induction of a Radio-Frequency Alternating Electric Field (RFAEF) in water at a specific range of frequency and antenna voltage, along with its distinct sinewave waveform, changes the way minerals precipitate, minimizing hard-lime scale by producing instead a non-adherent mineral powder in the bulk water. Moreover, the unsaturated solution that is created, along with enhanced carbon dioxide production, dissolves gradually the existing scale in plumbing tubes. Furthermore, the RFAEF inductance device demonstrates a major improvement over other pulsed-power systems, proving this electronic antifouling technique suitable for both hard and soft waters, as well as for large-scale applications.
Domaine de référence : Antifouling
Auteur Georgiou Dimitrios, Bendos Dimitrios, Kalis Manolis, Koutis Charilaos
Année de parution : 2018.
Mots-clés : Antifouling technology, Electronic descaling device, Limescale prevention, Plumbing tube, Radio-frequency alternating electric field.
Type de document : Article de revue.
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Risk Factors for Fouling Biomass : Evidence from Small Vessels in Australia

Résumé : Invasive marine non indigenous species are a major threat to marine biodiversity. Recreational vessels have been recognised by the scientific community as an important vector of non indigenous species, but have been slow to be picked up by recreational boaters/vessel owners and marina management. In particular, the translocation of invasive species from one region to another (domestically) may be at least partially due to recreational vessels. This paper reports on a statistical analysis of biomass samples gathered from the hull and other external surfaces of recreational yachts and fishing vessels in order to quantify the relationship between the wet biomass of biofouling and vessel-level characteristics. Unsurprisingly, we find that the number of days since the vessel was last cleaned was strongly related to the wet weight of biomass. The number of days since the vessel was last used was also related to the wet weight of biomass, yet was different depending on the type of vessel. Similarly, the median number of trips undertaken by the vessel was related to the wet weight of biomass, and varied according to the type of antifouling paint used by the vessel. The relationship between vessel size, as measured by hull surface area, and wet weight biomass per sample unit area was not significant. In order to reduce the domestic spread of invasive species, owners of small vessels (that sit around in marinas/moorings for extended periods between uses in particular) should be encouraged to maintain a regular cleaning and maintenance schedule, and use an appropriate type of antifouling paint.
Domaine de référence : Antifouling
Auteur Lane Stephen, Hollings Tracey, Hayes Keith R., McEnnulty Felicity R., Green Mark, Robinson Andrew P.
Année de parution : 2018.
Type de document : Article de revue.
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Anti-biofilm effect of a butenolide/polymer coating and metatranscriptomic analyses

Résumé : Butenolide is an environmentally friendly antifouling natural product, but its efficiency and mechanism in preventing biofilm formation have not been examined. Furthermore, controlling the release of butenolide from paints into seawater is technically challenging. A coating was developed by mixing butenolide with a biodegradable polymer, poly (ε-caprolactone)-based polyurethane, and a one-month in situ anti-biofilm test was conducted in a subtidal area. The constant release of butenolide from the surface suggested that its release was well controlled. Direct observation and confocal microscope investigation indicated that the coating was effective against both biofilm formation and attachment of large fouling organisms. Metatranscriptomic analysis of biofilm samples implied that the coating selectively inhibited the adhesion of microbes from a variety of phyla and targeted particular functional pathways including energy metabolism, drug transport and toxin release. These integrated analyses demonstrated the potential application of this butenolide/polymer coating as an anti-biofilm material.
Domaine de référence : Antifouling
Auteur Ding Wei, Ma Chunfeng, Zhang Weipeng, Chiang Hoyin, Tam Chunkit, Xu Ying, Zhang Guangzhao, Qian Pei-Yuan
Année de parution : 2018.
Mots-clés : ABC transporters, ATP-binding cassette transporters, Anti-biofilm, butenolide, butenolide, 5-octylfuran-2(5H)-one, CLSM, confocal laser scanning microscopy, COGs, Clusters of Orthologous Groups, DBTDL, dibutyltin dilaurate, DCOIT, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, FITC, fluorescein isothiocyanate, HPLC, high performance liquid chromatography, metatranscriptomics, PCA, principal component analysis, polymer coating, RTX, repeats-in-toxin.
Type de document : Article de revue.
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Inhibition of Bacterial Adhesion on Nanotextured Stainless Steel 316L by Electrochemical Etching

Résumé : Bacterial adhesion to stainless steel 316L (SS316L), which is an alloy typically used in many medical devices and food processing equipment, can cause serious infections along with substantial healthcare costs. This work demonstrates that nanotextured SS316L surfaces produced by electrochemical etching effectively inhibit bacterial adhesion of both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, but exhibit cytocompatibility and no toxicity toward mammalian cells in vitro. Additionally, the electrochemical surface modification on SS316L results in formation of superior passive layer at the surface, improving corrosion resistance. The nanotextured SS316L offers significant potential for medical applications based on the surface structure-induced reduction of bacterial adhesion without use of antibiotic or chemical modifications while providing cytocompatibility and corrosion resistance in physiological conditions.
Domaine de référence : Antifouling
Auteur Jang Yeongseon, Choi Won Tae, Johnson Christopher T., García Andrés J., Singh Preet M., Breedveld Victor, Hess Dennis W., Champion Julie A.
Année de parution : 2018.
Type de document : Article de revue.
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Enhancing passive sampling tools for detecting marine bioinvasions

Résumé : Early detection is important for successful management of invasive species, but optimising monitoring systems to detect multiple species from different taxonomic groups remains a major challenge. Settlement plates are often used to monitor non-indigenous marine species (NIMS) associated with vessel biofouling, but there have been few assessments of their fitness-for-purpose. We deployed arrays of settlement plates (“settlement arrays”) containing combinations of treatments that reflected conditions associated with the vessel transport pathway (i.e., copper based antifouling coatings, shaded habitat) to determine the treatment combinations that maximised NIMS diversity. Horizontal (shaded) treatments preferentially sampled higher NIS diversity than vertical plates. Although plates with copper-based biocides had larger proportions of NIS to indigenous species, they sampled only a subset of NIS diversity. Overall diversity was greatly enhanced through use of multiple treatments, demonstrating benefits of multi-faceted sampling arrays for maximising the potential taxonomic and species richness.
Domaine de référence : Antifouling
Auteur Tait Leigh, Inglis Graeme, Seaward Kimberley
Année de parution : 2018.
Mots-clés : Biodiversity, Biofouling, Copper, Invasion biology, Non-indigenous species (NIS), Settlement plates, Species richness.
Type de document : Article de revue.
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Anti-biofouling and antibacterial surfaces via a multicomponent coating deposited from an up-scalable atmospheric-pressure plasma-assisted CVD process

Résumé : Prevention of bacterial adhesion and biofilm formation on the surfaces of materials is a topic of major medical and societal importance. In this study, an up-scalable atmospheric-pressure plasma assisted deposition method is introduced to produce a multicomponent coating towards the elaboration of antibacterial and anti-biofilm surfaces. Interestingly, from a single catechol-based monomer, high deposition rates of highly chemically reactive functional thin films bearing catechol as well as quinone groups are achieved. The catechol-bearing thin film allows the in situ silver nanoparticle formation, assessed by scanning electron microscopy and EDX, whilst the enriched-quinone thin film is exploited for immobilizing dispersine B, an enzyme. In vitro functional assays demonstrated the dual antibacterial and anti-biofouling resistance properties of the coatings due to the antibacterial effect of silver and the fouling resistance of grafted dispersine B, respectively. Surfaces coated only with silver provide an antibacterial effect but fail to inhibit bacterial attachment, highlighting the usefulness of such dual-action surfaces. The approach presented here provides a simple and effective chemical pathway to construct powerful antibacterial surfaces for various industrial applications.
Domaine de référence : Antifouling
Auteur Moreno-Couranjou Maryline, Mauchauffé Rodolphe, Bonot Sébastien, Detrembleur Christophe, Choquet Patrick
Année de parution : 2018.
Type de document : Article de revue.
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Integration of Antifouling and Antibacterial Properties in Salt-Responsive Hydrogels with Surface Regeneration Capacity

Résumé : Development of new antimicrobial materials and strategies is of importance for many biomedical and industrial applications. In this work, we report a new strategy to integrate distinct antimicrobial, antifouling, and stimuli-responsive properties into a single hydrogel to realize bacteria resistance, killing, and releasing functions. To achieve this design, we conjugated salt-responsive, anti-polyelectrolyte polyDVBAPS (poly(3-(dimethyl(4-vinylbenzyl) ammonio) propyl sulfonate)) with antifouling polyHEAA (poly(N-hydroxyethyl acrylamide)) and antimicrobial AgNPs (silver nanoparitcles) to form a hybrid hydrogel of polyDVBAPS-g-polyHEAA@AgNPs, among which polyHEAA functions as a general antifouling background to prevent bacteria adsorption on the surface, AgNPs act as antimicrobial agents to kill bacteria on the surface, and polyDVBAPS uses its unique salt-responsive, anti-polyelectrolyte property to release adherent bacteria from the surface. In this design, polyDVBAPS-g-polyHEAA@AgNPs hydrogels not only effectively resist bacteria attachment and kill the adherent bacteria, but also regenerate the antifouling surface of the hydrogel by releasing the adhered bacteria to keep the surface free from bacteria. PolyDVBAPS-g-polyHEAA@AgNPs hydrogels exhibited high surface resistance to bacteria adsorption (<106 cells/cm2) for up to 4 days, high antibacterial activity by killing ~99 % attached bacteria of both E. coli and S. aureus, and surface regeneration ability by releasing >96% adherent live or dead bacteria from the surface upon a simply treatment of 1.0 M NaCl solution for 10 min. Upon the release of AgNPs, AgNPs were reloaded into the hydrogel again to achieve multiple antifouling, bactericidal, and regenerative properties. This work demonstrates a new design for a new multifunctional hydrogel to effectively achieve antimicrobial, antifouling, and surface regeneration properties, making this hydrogel very promising for antimicrobial applications.
Domaine de référence : Antifouling
Auteur Zhang Dong, Fu Yanhong, Huang Lei, Zhang Yanxian, Ren Baiping, Zhong Mingqiang, Yang Jintao, Zheng Jie
Année de parution : 2018.
Type de document : Article de revue.
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Automated Image Analysis of Offshore Infrastructure Marine Biofouling

Résumé : In the UK, some of the oldest oil and gas installations have been in the water for over 40 years and have considerable colonisation by marine organisms, which may lead to both industry challenges and/or potential biodiversity benefits (e.g., artificial reefs). The project objective was to test the use of an automated image analysis software (CoralNet) on images of marine biofouling from offshore platforms on the UK continental shelf, with the aim of (i) training the software to identify the main marine biofouling organisms on UK platforms; (ii) testing the software performance on 3 platforms under 3 different analysis criteria (methods A–C); (iii) calculating the percentage cover of marine biofouling organisms and (iv) providing recommendations to industry. Following software training with 857 images, and testing of three platforms, results showed that diversity of the three platforms ranged from low (in the central North Sea) to moderate (in the northern North Sea). The two central North Sea platforms were dominated by the plumose anemone Metridium dianthus; and the northern North Sea platform showed less obvious species domination. Three different analysis criteria were created, where the method of selection of points, number of points assessed and confidence level thresholds (CT) varied: (method A) random selection of 20 points with CT 80%, (method B) stratified random of 50 points with CT of 90% and (method C) a grid approach of 100 points with CT of 90%. Performed across the three platforms, the results showed that there were no significant differences across the majority of species and comparison pairs. No significant difference (across all species) was noted between confirmed annotations methods (A, B and C). It was considered that the software performed well for the classification of the main fouling species in the North Sea. Overall, the study showed that the use of automated image analysis software may enable a more efficient and consistent approach to marine biofouling analysis on offshore structures; enabling the collection of environmental data for decommissioning and other operational industries.
Domaine de référence : Antifouling
Auteur Gormley Kate, McLellan Faron, McCabe Christopher, Hinton Claire, Ferris Joseph, Kline David I., Scott Beth E.
Année de parution : 2018.
Mots-clés : artificial reefs, automated image analysis, biofouling, CoralNet, offshore infrastructure.
Type de document : Article de revue.
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Controlled Release Antifouling Coating Composition Via Biocide Interaction

Résumé : The present application discloses a solvent-borne antifouling coating composition comprising an erodible non-silicone based binder system, one or more metal-containing biocides (like cuprous oxide, copper pyrithione (copper omadine), zinc pyrithione (copper omadine) and zinc-ethylenebis(dithiocarbamate) (Zineb)), and one or more non-reactive polyoxyalkylene- modified silicone oils, in particular PEG/PPG-modified silicone oils, such as those having a hydrophilic-lipophilic balance (HLB) of e.g. 9-18. The application also discloses a marine structure comprising on at least a part of the outer surface thereof an outermost self- polishing antifouling coat or coating system.
Domaine de référence : Antifouling
Auteur ANDRES MARTINEZ, HOFFMANN Markus
Année de parution : 2017.
Type de document : Brevet.
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Method and Apparatus for Removing Biofouling From a Protected Surface in a Liquid Environment

Résumé : A system includes a UV light source and an optical medium coupled to receive UV light from the UV light source. The optical medium is configured to emit UV light proximate to a surface from which biofouling is to be removed once the biofouling has adhered to the protected surface. A method corresponds to the system.
Domaine de référence : Antifouling
Auteur Whelan Colin S., Thoren Matthew D., Piper Andrew M., DiMare Joseph C.
Année de parution : 2017.
Type de document : Brevet.
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Multivariate analysis of attachment of biofouling organisms in response to material surface characteristics.

Résumé : Multivariate analyses were used to investigate the influence of selected surface properties (Owens-Wendt surface energy and its dispersive and polar components, static water contact angle, conceptual sign of the surface charge, zeta potentials) on the attachment patterns of five biofouling organisms (Amphibalanus amphitrite, Amphibalanus improvisus, Bugula neritina, Ulva linza, and Navicula incerta) to better understand what surface properties drive attachment across multiple fouling organisms. A library of ten xerogel coatings and a glass standard provided a range of values for the selected surface properties to compare to biofouling attachment patterns. Results from the surface characterization and biological assays were analyzed separately and in combination using multivariate statistical methods. Principal coordinate analysis of the surface property characterization and the biological assays resulted in different groupings of the xerogel coatings. In particular, the biofouling organisms were able to distinguish four coatings that were not distinguishable by the surface properties of this study. The authors used canonical analysis of principal coordinates (CAP) to identify surface properties governing attachment across all five biofouling species. The CAP pointed to surface energy and surface charge as important drivers of patterns in biological attachment, but also suggested that differentiation of the surfaces was influenced to a comparable or greater extent by the dispersive component of surface energy.
Domaine de référence : Antifouling
Auteur Gatley-Montross C. M., Finlay J. A., Aldred N., Cassady H., Destino J. F., Orihuela B., Hickner M. A., Clare A. S., Rittschof D., Holm E. R., Detty M. R.
Année de parution : 2017.
Type de document : Article de revue.
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Antifouling processes and toxicity effects of antifouling paints on marine environment. A review

Résumé : The production infrastructure in aquaculture invariably is a complex assortment of submerged components with cages, nets, floats and ropes. Cages are generally made from polyamide or high density polyethylene (PEHD). All of these structures serve as surfaces for biofouling. However, cage nets and supporting infrastructure offer fouling organisms thousands of square meters of multifilament netting. That's why, before immersing them in seawater, they should be coated with an antifouling agent. It helps to prevent net occlusion and to increase its lifespan. Biofouling in marine aquaculture is a specific problem and has three main negative effects. It causes net occlusion and so restricts water and oxygen exchange. Besides, the low dissolved oxygen levels from poor water exchange increases the stress levels of fish, lowers immunity and increases vulnerability to disease. Also, the extra weight imposed by fouling causes cage deformation and structural fatigue. The maintenance and loss of equipment cause the increase of production costs for the industry. Biocides are chemical substances that can prohibit or kill microorganisms responsible for biofouling. The expansion of the aquaculture industry requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. Unfortunately, the use of biocides in the aquatic environment has proved to be harmful as it has toxic effects on the marine environment. The most commonly used biocides in antifouling paints are Tributyltin (TBT), Chlorothalonil, Dichlofluanid, Sea-Nine 211, Diuron, Irgarol 1051 and Zinc Pyrithione. Restrictions were imposed on the use of TBT, that's why organic booster biocides were recently introduced. The replacement products are generally based on copper metal oxides and organic biocides. This paper provides an overview of the effects of antifouling biocides on aquatic organisms. It will focus on the eight booster biocides in common use, despite little data are available for some of them. Toxicity values and effects of these antifoulants will also be mentioned for different species of fish, crustaceans, invertebrates and algae.
Domaine de référence : Antifouling
Auteur Amara Intissar, Miled Wafa, Slama Rihab Ben, Ladhari Neji
Année de parution : 2018.
Mots-clés : Algae, Antifouling agents, Biofouling, Crustacean, Fish, Invertebrate.
Type de document : Article de revue.
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Sea-trial verification of ultrasonic antifouling control

Résumé : An ultrasonic antifouling treatment was applied to a 96,000 m3 class drill-ship to verify its feasibility through a sea-trial. Soon after the hull cleaning had been performed, six ultrasonic projectors were evenly deployed around the starboard shell plate. Driven by a 23 kHz sinusoidal ultrasound in an intermittent manner, the projectors emitted a high-intensity sound reaching 214 dB at the source level causing cavitation around the adjacent water and eventually deterring the settlement of marine fouling organisms. Underwater photographs acquired after four months showed fairly clean slabs on the starboard side, but heavy fouling on the port side. This experiment revealed that ultrasound treatment is a promising method for inhibiting fouling accumulation, even for large-scale ship applications.
Domaine de référence : Antifouling
Auteur Park Ji-Soo, Lee Jeung-Hoon
Année de parution : 2017.
Mots-clés : antifouling, fouling rating (FR), sea-trial, Ultrasound.
Type de document : Article de revue.
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Bioinspired Aryldiazonium Carbohydrate Coatings : Reduced Adhesion of Foulants at Polymer and Stainless Steel Surfaces in a Marine Environment

Résumé : Bioinspired Aryldiazonium Carbohydrate Coatings: Reduced Adhesion of Foulants at Polymer and Stainless Steel Surfaces in a Marine Environment
Domaine de référence : Antifouling
Année de parution : 2017.
Type de document : Page Web.
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The impact of artificial surfaces on marine bacterial and eukaryotic biofouling assemblages : A high-throughput sequencing analysis

Résumé : Vessel hulls and underwater infrastructure can be severely impacted by marine biofouling. Knowledge on which abiotic conditions of artificial structures influence bacterial and eukaryotic community composition is limited. In this study, settlement plates with differing surface texture, orientation and copper-based anti-fouling coatings were deployed in a marina. After three months, biofouling samples were collected and bacterial and eukaryotic communities characterised using DNA metabarcoding. The copper anti-fouling coating treatments incurred the most significant compositional changes (p ≤ 0.001) within both domains. Bacterial diversity decreased, with Gammaproteobacteria becoming the dominant phylum. In contrast, protist diversity increased as well as opportunist nematodes and bryozoans; urochordates and molluscs became less abundant. Network analyses displayed complex relationships on untreated plates, while revealing a simpler, but disturbed and unstable community composition on the anti-fouling coated plates. These networks of copper treatments displayed opportunist taxa that appeared as key organisms in structuring the bacterial and eukaryotic communities.
Domaine de référence : Antifouling
Auteur von Ammon Ulla, Wood Susanna A., Laroche Olivier, Zaiko Anastasija, Tait Leigh, Lavery Shane, Inglis Graeme, Pochon Xavier
Année de parution : 2017.
Mots-clés : Anti-fouling coating, Bacterial and eukaryotic communities, Biological networks, High-throughput sequencing (HTS), Marine biofouling, Metabarcoding.
Type de document : Article de revue.
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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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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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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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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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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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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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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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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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Ce projet est financé par le Fonds Européen de Développement Régional, la Région Normandie et le Conseil Départemental de la Manche.