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Design load estimation with IFORM-based models considering long-term extreme response for mooring systems

Résumé : In this paper, we present an extension of the alternative environmental contour approach based on inverse first-order reliability theory in a three-dimensional model that accounts for short-term extreme response uncertainties. Subsequently, the long-term extreme tension under wave excitation loads is investigated to evaluate return levels for the design of mooring systems. Tension extreme data are derived from time-domain simulations of a floating coupled system using the peak-over-threshold method to determine short-term load distribution. A linear interpolation scheme is utilised to establish the parametric model using distribution parameters and wave data. Long-term extreme loads are estimated using a simplified discrete approach combined with Monte Carlo simulations, which helps avoid the tedious task of direct integration. The applicability of these load assessment models is demonstrated and discussed using an example of a semi-submersible platform situated at a 500-m water depth, and the results are compared with one- and two-dimensional environmental contour-based models.
Domaine de référence : EMR
Auteur Zhao Yuliang, Dong Sheng
Année de parution : 2020.
Mots-clés : Design load, environmental contour, inverse reliability model, long-term extreme response, Monte Carlo simulation, mooring system.
Type de document : Article de revue.
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Crack growth direction effects on corrosion-fatigue behaviour of offshore wind turbine steel weldments

Résumé : In this study corrosion-fatigue tests have been conducted on fracture mechanics specimens extracted from an S355 G10+M structural steel welded plate. The tests have been performed on compact tension specimens with the crack tip located in the heat affected zone. The corrosion-fatigue test results from this study have been compared with the data available on the base metal as well as air tests on the same material. Moreover, the obtained results have been compared with the corrosion-fatigue data available in the literature on a wide range of steels and also the fatigue trends for welded joints in free-corrosion condition recommended in the BS7910 Standard. The effect of the specimen orientation, with respect to the weld region, is also examined in this study and it has been found that higher corrosion-fatigue crack growth rates are generally observed in the tests with 0° orientation. The results have also shown that the corrosive environment has significant effects on the fatigue crack growth acceleration at the beginning of the tests; however, as the crack propagates, the environmental damage effect on crack growth behaviour becomes less pronounced. The results presented in this study are discussed in terms of improvement in the structural integrity assessment of offshore wind turbine monopiles.
Domaine de référence : EMR
Auteur Jacob Anais, Mehmanparast Ali
Année de parution : 2021.
Mots-clés : Fatigue crack growth, HAZ, Offshore wind turbine monopile, Simulated seawater.
Type de document : Article de revue.
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Analysis of the influence of climate change on the fatigue lifetime of offshore wind turbines using imprecise probabilities

Résumé : When discussing the connection of wind energy and climate change, normally, the potential of wind energy to reduce green house gas emissions is emphasised. Hence, effects of wind energy on climate change are analysed. However, what about the other direction? What is the impact of climate change on wind energy? Recently, the effect of a reversal in global terrestrial stilling,that is, an increase in global wind speeds in the last decade, on the wind energy production has been analysed. Certainly, knowledge about potential changes in energy production is essential to plan future energy supply. Nonetheless, at least similarly important is the effect on loads acting on wind turbines. Increasing loads due to higher wind speeds might reduce wind turbine lifetimes and yield higher costs. Moreover, especially for already existing turbines, it might even affect the structural reliability. Since the impact of climate change on wind turbine loads is largely unknown, it is studied in this work in more detail. For this purpose, different existing models for predicted changes in wind speed and air temperature and their uncertainties are used to forecast the environmental conditions an exemplary offshore wind turbine is exposed to. Subsequently, for this turbine, the lifetime fatigue damages are calculated for different prediction models. It is shown that the expected changes in lifetime fatigue damages are present but relatively small compared to other uncertainties in the fatigue damage calculation.
Domaine de référence : EMR
Auteur Hübler Clemens, Rolfes Raimund
Année de parution : 2020.
Mots-clés : climate change, fatigue, imprecise probabilities, scattering environmental conditions, uncertainty, wind energy.
Type de document : Article de revue.
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Inter-sectoral relations to accelerate technological innovation systems formation : determinants of actors‘ entry into marine renewable energy technologies

Résumé : Sistema de gestão de informação científica do ISCTE-IUL
Domaine de référence : EMR
Auteur Bento Nuno, Fontes Maria, Barbosa Juliana
Année de parution : 2020.
Type de document : Article de revue.
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Analytical Assessment of the Mooring System Stiffness

Résumé : The definition of the mooring systems is one of the most important stages on the design any offshore unit. Some effects associated with it, on the responses of the floating body, are still under investigation. In this context, the full nonlinear high-order hierarchical modeling and the numerical integration of the resulting equations of motion might not be the most cost effective approach for the evaluation of those effects during the early design process. Thus, an expedite analytical formulation to assess the mooring system stiffness, a tool that could help the initial design and analysis. Using classic approaches from Analytical Mechanics, the nonlinear generalized restoring forces associated with the mooring acting on the vessel due to the mooring lines are formulated. The six-degree-of-freedom (DoF) problem is herein addressed. The stiffness matrix is obtained from the linearization of the generalized forces around a generic position. Mooring line characteristic tension function is an input of the method. The closed formulation does not requires a specific line model, although the formulation for a multi-segment mooring line is also derived. The methodology is applied taking the OC4-DeepCwind Floating Wind Turbine semi-submersible platform as a case study. Two Spread Mooring Systems arrangements are studied, in order to demonstrate the use of the presented formulation as a design tool. The calculated mooring system stiffness matrix, evaluated at the trivial equilibrium position, exhibits good agreement with numerical results found in the literature by high hierarchy models. Additionally, the stiffness coefficients are evaluated for other positions than the trivial equilibrium one in the form of colored maps. The natural periods of the motions on the horizontal plane are also mapped. These maps help to understand the effects of the static vessel mean position on the mooring system stiffness and, consequently, on the natural periods associated with the motions on the horizontal plane. Considering the original OC4 mooring system, the effects of the mooring line pre-tensioning are also investigated. Some conclusions on the axial stiffness of catenary cables are also made. The main contributions of the present master dissertation are: (i) the stiffness matrix analytical closed formulation and (ii) the use of colored maps to evaluate the stiffness and the natural periods as functions of the mean offset position. The present master dissertation brings then an innovative closed-form formulation with important practical applications.
Domaine de référence : EMR
Auteur Amaral Giovanni Aiosa Do
Année de parution : 2020.
Type de document : Article de revue.
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Amaral - 2020 - Analytical Assessment of the Mooring System Stiffn.pdf

Domaine de référence : EMR
Année de parution : 0.
Type de document : Pièce jointe.
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Rotational sampling of waves by tidal turbine blades

Résumé : The presence of waves exposes tidal stream turbines to large and cyclic hydrodynamic loads which significantly influence the design requirements for tidal turbine blades. Here we describe a loading phenomenon not previously considered in literature caused as blades rotationally sample an oscillating and vertically decaying wave-induced velocity field. Although implicitly incorporated into numerical models, the dominant causes and relative influence have not previously been considered.In this article this effect is described through theoretical analysis and validated through scaled experiments; including irregular waves at angles to the rotor and current field. The associated loads are found to be strongly correlated to the wavenumber. The nature of the rotational-sampling-effect is confirmed through analysis of the experimental results, where characteristic sidebands are effectively predicted in the blade root bending moment spectra. It is estimated to account for between 8% and 16% of the fatigue damage and between 7% and 13% of the peak root bending moment for the conditions tested. A key finding is that two bilaterally-symmetrical oblique wave conditions do not produce equivalent loading patterns: one produces higher frequency oscillations. Additionally, it is found that the frequency of these loads reduces linearly with rotational speed; highlighting another consideration for tidal stream turbine operation.
Domaine de référence : EMR
Auteur Draycott S., Steynor J., Nambiar A., Sellar B., Venugopal V.
Année de parution : 2020.
Mots-clés : Blade fatigue, Irregular wave loads, Oblique waves, Rotational sampling, Sidebands, Tidal Stream turbine.
Type de document : Article de revue.
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A low-order wake interaction model for ocean current turbine arrays operating in turbulent flow

Résumé : Ocean Current Turbines (OCTs), which function similarly to wind and tidal turbines, represent a promising technology for harnessing the energy from oceanic currents. The power extracted by the turbines can be significantly affected by the turbulence intensity in the upstream flow. For turbines distributed in an arrayed configuration, the highly turbulent wakes behind each upstream turbine must also be considered. In this presentation, we describe a low-order analytical wake interaction model capable of estimating the total array power of OCTs operating in any stacked configuration, and embedded in a flow with Turbulence Intensity (TI). The model incorporates both near and far-wake effects associated with each turbine, and has been validated using high-resolution Large Eddy Simulations (LES) performed using the STAR-CCM software. The simulations were driven by realistic ocean turbulence conditions derived from Gulf Stream current measurements. The analytic model was validated over a wide range of turbulence intensities and OCT array configurations, and can also be applied to evaluate the performance of wind turbine installations.
Domaine de référence : EMR
Année de parution : 2020.
Type de document : Article de colloque.
Source : American Physical Society
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Numerical simulation of violent breaking wave impacts on a moored offshore wind turbine foundation over nonuniform topography

Résumé : Breaking wave impact on a moored offshore wind turbine foundation over a variable-depth seabed is considered in time domain, based on the fully nonlinear potential theory. An adiabatic model is used to simulate the variation in air cavity volume and pressure imposed on the dynamic boundary condition of the inner free surface. The whole impact process is solved using the dual coordinate system, where a local stretched coordinate system is adopted to determine both the shape and location of the initial impact zone, while the global coordinate system is applied to track further development of both the upper and lower jets. A higher-order boundary element method is introduced to establish water integral equations of the main fluid domain and the thin jet, which are combined together with the match conditions of pressure and velocity on the interface. By employing auxiliary functions, the temporal derivative of velocity potential is accurately obtained to decouple the mutual dependence of body and fluid motions. A specified global coordinate-based finite element method is used to derive the dynamic equilibrium equation of the mooring line element. Through the hinged condition at the fairlead location, the motion equations of the wind turbine and its mooring system are simultaneously solved using the Newton–Raphson iterative method. Extensive simulations are performed and discussed for the free surface profile, pressure distribution, body motion, and air cavity features. The wind turbine moored at the seabed with larger slope was found to experience relatively higher air cavity pressure and achieve larger rotational speed, smaller horizontal, and vertical speed.
Domaine de référence : EMR
Auteur Cheng Yong (程勇), Ji Chunyan (嵇春艳)
Année de parution : 2020.
Type de document : Article de revue.
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Offshore wind turbine cost structure analysis

Résumé : Offshore wind electricity is booming, and turbines are growing in size in order to reduce the levelized cost of energy (LCOE). To forecast the future offshore wind energy generation costs, it is common sense to predict and calculate the future LCOE. With the increasing size of the offshore turbines, the weighted share of the capital expenditure (CAPEX) compared to the operational costs (OPEX) of LCOE is growing. And thus, the accuracy of the calculations of CAPEX plays an increasing role. Previous research demonstrated an extensive research gap for accurate scaling and calculation models for offshore wind turbine CAPEX. Therefore, this paper provides the scientific foundation by presenting the offshore direct drive turbine cost drivers. Aiming to use the presented results in future research in order to create accurate cost calculation models for the turbine main components and with it the creation of an overall turbine CAPEX scaling model.
Domaine de référence : EMR
Auteur Meißner Maximilian
Année de parution : 2020.
Type de document : Article de revue.
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An opportunistic maintenance strategy for offshore wind turbine system considering optimal maintenance intervals of subsystems

Résumé : Operation and maintenance (O&M) costs account for a large proportion of the total costs for offshore wind energy. Performing a reasonable maintenance strategy is an effective approach to reduce O&M costs and gain more profits. In this paper, an opportunistic maintenance strategy for offshore wind turbine systems considering maintenance intervals of each subsystem is proposed to minimize the total maintenance cost. First, a Non-homogeneous Continuous-Time Markov Process based state transition model is established to study degradation process of subsystems. The influence of maintenance time schedule on the maintenance cost is studied to obtain the optimal maintenance intervals of each subsystems. Then, an opportunistic maintenance model considering economic dependencies between multiple subsystems is proposed to optimize the maintenance strategy by combining maintenance activities of individual subsystems to a grouping maintenance activity. A numerical example is used to indicate the significant effectiveness of the maintenance model. The result shows that the total maintenance cost of an offshore wind turbine system will be reduced by adopting the opportunistic maintenance strategy when compared with conventional preventive maintenance strategy.
Domaine de référence : EMR
Auteur Li Mingxin, Wang Mian, Kang Jichuan, Sun Liping, Jin Peng
Année de parution : 2020.
Mots-clés : Cost-effective maintenance, Maintenance optimization, Offshore wind energy, Operation and maintenance.
Type de document : Article de revue.
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Minute-scale detection and probabilistic prediction of offshore wind turbine power ramps using dual-Doppler radar

Résumé : Predicting the occurrence of strong and sudden variations in wind power, so-called ramp events, has become one of the main challenges for the operation of power systems with large shares of wind power. In this paper, we investigate 14 ramp events of different magnitudes and minute-scale durations observed by a dual-Doppler radar system at the Westermost Rough offshore wind farm. The identified ramps are characterised using radar observations, turbine data and data from the Weather Research and Forecasting (WRF) model. A remote sensing-based forecasting methodology that propagates wind speeds upstream of wake-free turbines is extended here to the whole farm, by including corrections for wake effects. The methodology aims to probabilistically forecast the wind turbines' power in the form of density forecasts. The ability to predict ramp events of different magnitudes is evaluated and compared with probabilistic statistical and physical benchmarks. During the observed ramp events, the remote sensing-based forecasting model strongly outperforms the benchmarks. We show here that remote sensing observations such as radar data can significantly enhance very short-term forecasts of wind power.
Domaine de référence : EMR
Auteur Valldecabres Laura, Bremen Lueder von, Kühn Martin
Année de parution : 2020.
Mots-clés : density forecast, remote sensing, transient ramp, very short-term forecast, weather front.
Type de document : Article de revue.
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Multi-component modeling and classification for failure propagation of an offshore wind turbine

Résumé : Purpose Improving reliability is a key factor in reducing the cost of wind energy, which is strongly influenced by the cost of maintenance operations. In this context, this paper aims to propose a degradation model that describes the phenomenon of fault propagation to apply proactive maintenance that will act on the cause of failure to prevent its reoccurrence as well as to improve future system designs. Design/methodology/approach The methodology adopted consists in identifying the different components of a wind turbine, their causes and failure modes, and then, classifying these components according to their causes of failure. Findings The result is a classification of the different components of a wind turbine according to their failure causes. From the obtained classification, the authors observed that the failure modes for one component are a failure cause for another component, which describes the phenomenon of failure propagation. Originality/value The different classifications existing in the literature depend on the nature, position and function of the different components. The classification of this study consists in grouping the components of a wind turbine according to their failure causes to develop a degradation model considering the propagation of failure in the field of wind turbines.
Domaine de référence : EMR
Auteur Bezzaoucha Fatima Souad, Sahnoun M’hammed, Benslimane Sidi Mohamed
Année de parution : 2020.
Mots-clés : Classification, Degradation model, Failure propagation, Failure rate, Markov model, Proactive maintenance, Reliability, Stochastic dependency, Wind turbine.
Type de document : Article de revue.
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Succession in epibenthic communities on artificial reefs associated with marine renewable energy facilities within a tide-swept environment

Résumé : Abstract. Although colonization of artificial structures by epibenthic communities is well-documented overall, our understanding of colonization processes is l
Domaine de référence : EMR
Auteur Taormina Bastien, Percheron Arthur, Marzloff Martin P., Caisey Xavier, Quillien Nolwenn, Lejart Morgane, Desroy Nicolas, Dugornay Olivier, Tancray Aurélien, Carlier Antoine
Année de parution : 2020.
Type de document : Article de revue.
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A survey on modeling and control of thruster-assisted position mooring systems

Résumé : This review presents a systematic summary of the state-of-the-art development of technological solutions, modeling, and control strategies of thruster-assisted position mooring (TAPM) systems. The survey serves as a starting point for exploring automatic control and real-time monitoring solutions proposed for TAPM systems. A brief historical background of the mooring systems is given. The kinematics and a simplified kinetic control-design model of a TAPM system are derived in accordance with established control methods, including a quasistatic linearized model for the restoring and damping forces based on low-frequency horizontal motions of the vessel. In addition, another two mooring line models, i.e., the catenary equation and the finite element method model, are presented for the purpose of higher-fidelity simulations. The basic TAPM control strategies are reviewed, including heading control, surge-sway damping, roll–pitch damping (for semisubmersibles), and line break detection and compensation. Details on the concepts of setpoint chasing for optimal positioning of a vessel at the equilibrium position are discussed based on balancing the mooring forces with the environmental loads and avoiding mooring line failure modes. One method for setpoint chasing is the use of a structural reliability index, accounting for both mean mooring line tensions and dynamic effects. Another method is the use of a lowpass filter on the position of the vessel itself, to provide a reference position. The most advanced method seems to be the use of a fault-tolerant control framework that, in addition to direct fault detection and isolation in the mooring system, incorporates minimization of either the low-frequency tensions in the mooring lines or minimization of the reliability indices for the mooring lines to select the optimal directions for the setpoint to move. A hybrid (or supervisory switching) control method is also presented, where a best-fit control law and observer law are automatically selected among a bank of control and observer algorithms based on the supervision of the sea-state and automatic switching logic.
Domaine de référence : EMR
Auteur Skjetne Roger, Ren Zhengru
Année de parution : 2020.
Mots-clés : Fault-tolerant control, Hybrid control, Modeling, Mooring, Optimal setpoint, Position mooring, Thruster-assisted position mooring.
Type de document : Article de revue.
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Development of a model predictive controller for floating offshore wind turbines

Résumé : In this work, an Economic Model Predictive Controller for a floating offshore wind turbine is presented. The classical Model Predictive Control for floating offshore wind turbines provides promising results. In addition, research on onshore wind turbines revealed the potential of the economic control method, which can improve the closed-loop behavior and simplify the control design in comparison to the classical version of this control method. The aim of this work is, to develop a novel Economic Model Predictive Controller for a floating offshore wind turbine based on these two research results. A simplified low order model of a floating offshore wind turbine serves as a basis for the controller design. Including the disturbance preview and constraints, the controller computes optimal trajectories for the blade pitch and the generator torque. To apply the control technique to a floating offshore wind turbine two things have to be done: Firstly, the cost function is designed, to fulfill the main objectives of, maximizing the generated power and alleviating the structural fatigues. Secondly, the constraints are integrated into the control problem. After selecting a suitable solver, the controller is discretized and scaled, thus a proper implementation and smooth operation is possible. Afterwards, the successful functioning of the algorithm, a multi-objective optimization is done, to find appropriate weights to adjust the cost function for the required objectives. Finally, the developed controller is tested with realistic wind and wave disturbances. A significant reduction of the standard deviation of the generated power can be shown, while maintaining real time capability. Furthermore, the structural fatigues of the tower and the platform are decreased.
Domaine de référence : EMR
Auteur Nann Samuel
Année de parution : 2020.
Type de document : Article de revue.
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Stochastic Modeling of Tidal Generation for Transient Stability Analysis : A Case Study based on the All-Island Irish Transmission System

Résumé : The renewable energy currently generated in the Irish system is almost entirely supplied by wind power plants. However, in the sea around Ireland there is a significant tidal energy potential. This paper provides a comparison of these two renewable energy sources, namely wind and tidal, in terms of short-term variability and its impact on the dynamic behavior of the system. With this aim, stochastic models of the short-term variability of these two energy sources are proposed. Simulation results indicate that tidal generation leads to larger frequency variations than those that are caused by wind generation. The paper also shows that the inclusion of frequency control in tidal power plants effectively mitigates such fluctuations.
Domaine de référence : EMR
Auteur Jónsdóttir Guðrún Margrét, Milano Federico
Année de parution : 2020.
Mots-clés : Irish power system, Stochastic differential equations, Stokes wave model, Tidal generation, Wind generation.
Type de document : Article de revue.
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Dynamic analysis of semi-submersible production platform under the failure of mooring lines

Résumé : This paper quantitatively studies the transient dynamic response of a semi-submersible production platform while the loss of one or several positioning mooring lines. A semi-submersible platform, production risers, and positioning mooring lines are all included in the numerical simulation. Increased motion of the semi-submersible platform, tension variation of the remaining mooring lines/risers and the risk of mooring line or riser clashing are all investigated through fully coupled time-domain analysis. Combined environmental loads are selected from irregular waves and the steady current varying from very rough to extreme sea conditions. Three dimension radiation/diffraction theories and Morison's equation are applied to calculate first-order wave force and second-order mean drift force of floating semi-submersible platform. Nonlinear time-domain finite element methods are employed to analyze the behavior of mooring lines and risers. Results show that lost of mooring lines has a significant impact to reduce the platform’s stability performance. The tension of the rest lines is also increased accordingly. Remaining lines which are closer to the failed lines will have larger tension increase to compensate. Line-Line distance provides practical information for the risk of clashing investigation.
Domaine de référence : EMR
Auteur Chuang Zhenju, Chang Xin, Guo Bingjie, Lu Yu
Année de parution : 2020.
Mots-clés : coupling effect between platform and mooring system, mooring line failure, risk of lines clashing, tension variation of mooring line, the transient response of platform.
Type de document : Article de revue.
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Multicriteria analysis of seawater electrolysis technologies for green hydrogen production at sea

Résumé : The production of green hydrogen through the electrolysis of seawater using marine renewable energies offer numerous advantages. Nonetheless, the combination of marine renewables and electrolysis technologies has not reached commercial status yet. This study aims to see which electrolysis technology presents the best prospects of applicability in the short term by conducting a multicriteria comparison, where economic, environmental and social factors have been selected. Due to the different nature of the involved factors, the analysis is inherently complex. For its simplification, multicriteria decision-making methods are used. However, such methods could lead to various types of inconsistencies, and in order to avoid them, five distinct multicriteria decision-making methods have been employed. This combination enables checking the ranking consistency and its robustness, conferring the results a higher reliability. The results of the study reveal that Proton Exchange Membrane Electrolysis at sea presents the best prospects of applicability in the short term.
Domaine de référence : EMR
Auteur d’Amore-Domenech Rafael, Santiago Óscar, Leo Teresa J.
Année de parution : 2020.
Mots-clés : Alkaline electrolysis, MCDM, Multicriteria decision-making, PEM electrolysis, Renewable energy, Seawater electrolysis, Solid oxide electrolysis, Sustainable hydrogen.
Type de document : Article de revue.
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The energy yield potential of a large tidal stream turbine array in the Alderney Race

Résumé : This research provides an updated energy yield assessment for a large tidal stream turbine array in the Alderney Race. The original array energy yield estimate was presented in 2004. Enhancements to this original work are made through the use of a validated two-dimensional hydrodynamic model, enabling the resolution of flow modelling to be improved and the impacts of array blockage to be quantified. Results show that a range of turbine designs (i.e. rotor diameter and power capacity) are needed for large-scale development, given the spatial variation in bathymetry and flow across the Alderney Race. Array blockage causes a reduction in flow speeds in the array of up to 2.5 m s−1, increased flow speeds around the array of up to 1 m s−1 and a reduction in the mean volume flux through the Alderney Race of 8%. The annual energy yield estimate of the array is 3.18 TWh, equivalent to the electricity demand of around 1 million homes. The capacity factor of the array is 18%, implying sub-optimal array design. This result demonstrates the need for turbine rated speed to be selected based on the altered flow regime, not the ambient flow. Further enhancement to array performance is explored through increases to rotor diameter and changes to device micro-siting, demonstrating the significant potential for array performance improvement.This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.
Domaine de référence : EMR
Auteur Coles D. S., Blunden L. S., Bahaj A. S.
Année de parution : 2020.
Type de document : Article de revue.
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Underway velocity measurements in the Alderney Race : towards a three-dimensional representation of tidal motions

Résumé : The Alderney Race, located northwest of the Cotentin Peninsula (France), is a site with high tidal-stream energy potential. Circulation through the Alderney Race is complex, with current speed exceeding 3 m s−1 at neap tide. Towed acoustic Doppler current profiler (ADCP) measurements and static point velocity measurements were performed in July 2018 focusing on assessment of circulation and vertical structure of tidal currents. Transect surveys revealed peculiar features of local dynamics such as change in location of the tidal jet on ebb and flood flow. The spatial expanse of the tidal jet was quantified and regions with largely sheared or nearly homogeneous velocity distributions were identified on the cross-sections. Velocity profiles acquired along the cross-sections were accurately characterized using a power law. The spatial variability of the power-law exponent α was found to be large and correlated with the tidal conditions. The largest variation in profile shape was observed in the northern sector and assumed to be generated by the current interaction with a bathymetric constriction. The velocity profiles were found to vary from highly sheared on flood flow to nearly homogeneous on ebb flow, with corresponding range of power-law exponent α variation from 6 to 14. In the southern sector, over a relatively smooth bathymetry, the velocity profile shape was accurately approximated using the 1/7 power law with a range of variation of α from 6.5 to 8, with respect to the tidal conditions. To our knowledge, this is the largest field survey done using towed ADCP and the results could represent a significant advance in tidal site characterization and provide advanced information to turbine developers.This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race'.
Domaine de référence : EMR
Auteur Sentchev Alexei, Nguyen Thinh Duc, Furgerot Lucille, Bailly du Bois Pascal
Année de parution : 2020.
Type de document : Article de revue.
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Bilan thématique énergies marines renouvelables 2020 Programme d’investissements d’avenir - ADEME - Digital&Co - C. RAFFRAY - ADEME

Résumé : Ce bilan présente les chiffres-clés et les projets phares issus des appels à projets lancés par l'ADEME sur la thématique Énergies marines renouvelables du Programme d'investissements d'avenir. Les projets accompagnés par ces appels à projets couvrent les principaux thèmes des Énergies marines renouvelables (EMR) : - l'éolien offshore flottant - l'hydrolien marin et fluvial - l'énergie houlomotrice - l'énergie thermique des mers L'énergie éolienne en mer posée est traitée dans le bilan de la thématique « Énergies renouvelables». Les Énergies marines renouvelables (EMR) représentent un axe clef de la transition écologique et énergétique. Les enjeux pour la thématique sont l'accompagnement et la structuration de filières industrielles performantes et le développement de solutions compétitives et durables afin de répondre notamment aux objectifs fixés dans le cadre de la Programmation pluriannuelle de l'énergie (PPE). Plusieurs projets de recherche et développement, d'innovation et d'expérimentation préindustrielle, soutenus dans le cadre du PIA, permettent de répondre à ces enjeux. Ces projets portés par des entreprises en collaboration éventuellement avec d'autres entreprises et organismes de recherche, visent le développement et la démonstration de produits et services innovants. Ils contribuent à lever les verrous technologiques et à améliorer la performances des systèmes de production d'énergies marines renouvelables. Le Programme d'investissements d'avenir (PIA), créé par l'État en 2010 et mis en œuvre par le Secrétariat général pour l'investissement, a pour objectif d'augmenter la croissance potentielle de la France. L'ADEME en est l'opérateur pour les innovations destinées à accélérer la transition énergétique et environnementale. Environ 4 milliards d'euros de crédits lui sont dédiés sur la période 2010-2020 pour financer des projets innovants et développer les filières industrielles de demain.
Domaine de référence : EMR
Année de parution : 2020.
Type de document : Page Web.
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Control of power generated by a floating offshore wind turbine perturbed by sea waves

Résumé : Offshore wind energy is expected to provide a significant contribution to the achievement of the European Renewable Energy targets. One of the main technological issues affecting floating offshore wind turbines concerns generated power fluctuations and structural fatigue caused by sea-wave/platform interactions. This paper presents a fully-coupled aero/hydro/servo-mechanic model for response and control of floating offshore wind turbines in waves, suitable for preliminary design. The wind-turbine is described by a multibody model consisting of rigid bodies (blades and tower) connected by hinges equipped with springs and dampers (for realistic low-frequency simulation). The aerodynamic loads are evaluated through a sectional aerodynamic approach coupled with a wake inflow model. A spar buoy floating structure supports the wind turbine. The hydrodynamic forces are evaluated through a linear frequency-domain potential solver, with the free surface deformation effects included through a reduced-order, state-space model. An optimal controller is identified and applied for rejection of annoying fluctuations of extracted power and structural loads. The developed comprehensive model has been successfully applied to a floating version of the NREL 5 MW wind turbine for stability analysis, as well as for the analysis of uncontrolled and controlled responses to regular and irregular short-crested sea waves. The proposed controller, based on the combined use of blade pitch and generator torque as control variables and the application of an observer for non-measurable aerodynamic and hydrodynamic states estimation, has been demonstrated to be effective in a wide frequency range for alleviation of both generated power fluctuations and vibratory loads.
Domaine de référence : EMR
Auteur Pustina L., Lugni C., Bernardini G., Serafini J., Gennaretti M.
Année de parution : 2020.
Mots-clés : Aero-hydromechanics modeling, Control of stability and response, Energy harvesting, Floating offshore platform, Sea-wave/platform interaction, Wind turbine.
Type de document : Article de revue.
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Prediction of the fouling penalty on the tidal turbine performance and development of its mitigation measures

Résumé : The power coefficient for a horizontal axis tidal turbine is the determinant factor for the efficiency of a tidal energy system. To guarantee a highly efficient tidal turbine operating in the real sea environment for an enduring long period is of critical importance to the power production and hence the cost of energy. However, this performance is under the threat of marine biofouling and the biofouling effect on tidal turbine systems are barely known neither quantified. This paper focuses on the study of the roughness effect due to biofouling on the performance of a tidal turbine. A Reynolds Averaged Navier-Stokes model based Computational Fluid Dynamics (CFD) was developed to predict the effect of biofouling on a full-scale turbine. A roughness modelling that involves modified wall-functions in the CFD model was used representing the surface roughness caused by barnacle fouling. The simulations were conducted under different fouling scenarios for a range of tip speed ratios (TSR). The surface fouling resulted in up to 13% decrease in the power coefficient at the designed operating condition. The effect proved to be even more severe at higher TSRs, bringing narrower operating range of TSRs. The results also suggest that by lowering the operating TSRs for fouled turbines the fouling effect on efficiency losses can be minimised to ensure efficient operation between maintenances.
Domaine de référence : EMR
Auteur Song Soonseok, Demirel Yigit Kemal, Atlar Mehmet, Shi Weichao
Année de parution : 2020.
Mots-clés : Biofouling, computational fluid dynamics (CFD), Roughness effect, Tidal turbine.
Type de document : Article de revue.
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Statistical extrapolation methods for estimating extreme loads on wind turbine blades under turbulent wind conditions and stochastic material properties

Résumé : According to the IEC Standard 61400-1, designers of wind turbines are required to apply statistical extrapolation techniques to estimate the extreme (ultimate) load. In the present article, the certification procedure is assessed under the uncertainty of the material properties using a simulated load time series of the National Renewable Energy Laboratory 5MW reference wind turbine rotor. The uncertainty of the material properties is introduced in the elastic properties of the composite materials based on the OptiDAT composite material database. The assessment relies on the comparison of the estimated blade extreme loads and deflections, obtained for the reference and the stochastically varied material properties. It is found that the variability of the material properties does not affect the estimated ultimate moments (differences < 1.5%) but affects the maximum flapwise deflection (differences ~8%). It is concluded that the peak over threshold peak extraction technique and the three-parameter Weibull fitting functions outperform among those considered in the article.
Domaine de référence : EMR
Auteur Schinas Panagiotis N, Manolas Dimitris I, Riziotis Vasilis A, Philippidis Theodore P, Voutsinas Spyros G
Année de parution : 2020.
Type de document : Article de revue.
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Conceptual design and dynamic analysis of a novel passive floating offshore wind turbine structure

Résumé : In order to mitigate dynamic responses of floating offshore wind turbines (FOWTs) under combined wind-wave-current loading, employment of structural control techniques is often considered. In this paper, a novel concept of a passive FOWT structure is proposed to overcome the previous limitations on space and mass of tuned mass dampers (TMDs). The conceptual design is examined on the basis of a finite element model. The dynamic responses, mainly roll and pitch rotations, are compared between the controlled and uncontrolled FOWTs. Subsequently, a parametric study is conducted and the main parameters in the model are optimised accordingly. Finally, the optimal performance of the proposed FOWT structure demonstrates the effectiveness of the proposed design, and also its superiority over the existing concepts.
Domaine de référence : EMR
Auteur Liao Minmao, Wu Yuxing
Année de parution : 2020.
Type de document : Article de revue.
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Fault Detection of the Mooring system in Floating Offshore Wind Turbines based on the Wave-excited Linear Model

Résumé : Floating Offshore Wind Turbines (FOWTs) are more prone to suffer from faults and failures than bottom-fixed counterparts due to the severe wind and wave loads typical of deep water sites. In particular, mooring line faults may lead to unacceptably high operation and maintenance costs due to the limited accessibility of FOWTs. Detecting the mooring line faults is therefore critical, but the application of Fault Detection (FD) techniques has not been investigated yet. In this paper, an FD scheme based on a wave-excited linear model is developed to detect in a reliable way critical mooring line faults occurring at the fairlead and anchor ends. To reach the goal, a linear model of the FOWT is obtained by approximating the wave radiation and incident wave forces. Based on this model, an observer is built to predict the rigid rotor and platform dynamics. The FD scheme is thus implemented by comparing the Mahalanobis Distance of the observer prediction error against a probabilistic detection threshold. Numerical simulations in some selected fault scenarios show that the wave-excited linear model can predict the FOWT dynamics with good accuracy. Based on this, the FD scheme capabilities are demonstrated, showing that it is able to effectively detect two critical mooring line faults.
Domaine de référence : EMR
Auteur Liu Yichao, Fontanella Alessandro, Wu Ping, Ferrari Riccardo M. G., van Wingerden Jan-Willem
Année de parution : 2020.
Mots-clés : Electrical Engineering and Systems Science - Systems and Control.
Type de document : Article de revue.
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Coupled Motion Prediction of a Floating Tidal Current Power Station with Vertical Axis Twin-rotor Turbine

Résumé : Floating offshore tidal current turbines are usually moored in the sea, which will endure the wind-wave-current load in a long term. Power production of the tidal current turbine will result in extra excitation force acting on the platform, which will make the motion prediction and positioning system design of the floating platform more complicated. In order to predict the motion response of a floating tidal current power station, a coupled motion prediction method is established to explore the coupled interaction among the platform, the turbine and the mooring system. The turbine influence is considered as added mass and damping acting on the platform. Results shows that the fitted hydrodynamics agree well with numerical simulation results. The operation of the tidal turbine can increase the surge amplitude and pitch angle of catamaran, and the mooring line tension will increase as well. The research can provide some reference for motion response prediction and mooring positioning of a floating tidal current power station.
Domaine de référence : EMR
Auteur Hu Chao, Ma Yong, Li Lei, Li Tengfei
Année de parution : 2020.
Type de document : Article de revue.
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Array Arrangement on Vertical Axis Tidal Current Turbine Using Free Vortex Model

Résumé : In order to study the hydrodynamic performance of multiple vertical tidal current turbines, an analysis model based on free vortex model is proposed. By comparing with experiment data, the present model can obtain reasonable results. Then the hydrodynamic performance of twin-turbine and quad-turbine systems are studied using the present model. For twin-turbine system, five sets of turbines spacing and three sets of rotation direction are researched. And five sets of rotation direction are researched for quad-turbine system with one turbine spacing. By comparison, it is shown that positive effect on the relative power coefficient can be found at high TSR when turbines are side-by-side arrangement. At the same time, in most cases, it can obtain a higher relative power coefficient when turbines are rotating inward and have a smaller spacing. Due to the low computational time, the present method can be used in preliminary study on array arrangement of vertical axis tidal current turbine.
Domaine de référence : EMR
Auteur Han Ronggui, Ma Yong, Li Lei
Année de parution : 2020.
Type de document : Article de revue.
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Evaluating Mooring Line Test Procedures through the Application of a Round Robin Test Approach

Résumé : Innovation in materials and test protocols, as well as physical and numerical investigations, is required to address the technical challenges arising due to the novel application of components from conventional industries to the marine renewable energy (MRE) industry. Synthetic fibre ropes, widely used for offshore station-keeping, have potential application in the MRE industry to reduce peak mooring line loads. This paper presents the results of a physical characterisation study of a novel hybrid polyester-polyolefin rope for MRE mooring applications through a round robin testing (RRT) approach at two test facilities. The RRT was performed using standard guidelines for offshore mooring lines and the results are verified through the numerical modelling of the rope tensile behaviour. The physical testing provides quantifiable margins for the strength and stiffness properties of the hybrid rope, increases confidence in the test protocols and assesses facility-specific influences on test outcomes. The results indicate that the adopted guidance is suitable for rope testing in mooring applications and there is good agreement between stiffness characterisation at both facilities. Additionally, the numerical model provides a satisfactory prediction of the rope tensile behaviour and it can be used for further parametric studies.
Domaine de référence : EMR
Auteur Khalid Faryal, Davies Peter, Halswell Peter, Lacotte Nicolas, Thies Philipp R., Johanning Lars
Année de parution : 2020.
Mots-clés : marine renewable energy, mooring components, rope modelling, round robin testing, synthetic fibre ropes, testing infrastructure.
Type de document : Article de revue.
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Reliability analysis of mooring lines for floating structures using ANN-BN inference

Résumé : The harsh marine environment is a significant threat to the safety of floating structure systems. To address this, mooring systems have seen widespread application as an important component in the stabilization of floating structures. This article proposes a methodology to assess the reliability of mooring lines under given extreme environmental conditions based on artificial neural network–Bayesian network inference. Different types of artificial neural networks, including radial basis function neural networks and back propagation neural networks, are adopted to predict the extreme response of mooring lines according to a series of measured environmental data. A failure database under extreme sea conditions is then established in accordance with the failure criterion of mooring systems. There is a failure of mooring lines when the maximum tension exceeds the allowable breaking strength. Finally, the reliability analysis of moored floating structures under different load directions is conducted using Bayesian networks. To demonstrate the proposed methodology, the failure probability of a sample semi-submersible platform at a water depth of 1500 m is estimated. This approach utilizes artificial neural networks’ capacity for calculation efficiency and validates artificial neural networks for the response prediction of floating structures. Furthermore, it can also be employed to estimate the failure probability of other complex floating structures.
Domaine de référence : EMR
Auteur Zhao Yuliang, Dong Sheng, Jiang Fengyuan
Année de parution : 2020.
Type de document : Article de revue.
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Long-term fatigue damage assessment for a floating offshore wind turbine under realistic environmental conditions

Résumé : Offshore wind energy has gained widespread attention and experienced a rapid development due to the significantly increasing demand for renewable energy over the past few years. Currently, the development of offshore floating wind turbines attracts lots of attention to harvest more energy from a sustained higher speed of offshore wind away from the coastline. With stronger cyclic wind and wave loadings, the floating wind turbine could possibly experience severe fatigue damages at certain critical locations, which might lead to a catastrophic failure. Evaluating accumulated fatigue damage for a floating wind turbine during its entire lifetime, therefore, becomes essential and urgent. As demonstrated in the codes, specifications, or design practices, fatigue assessments require massive computational costs and pose challenges to numerical simulations since lots of dynamic analyses under different environmental scenarios need to be performed. To reduce the calculation cost for this time-consuming process while maintaining high accuracy, a probabilistic long-term fatigue damage assessment approach is proposed in the present study by implementing a C-vine copula model and a surrogate model. The C-vine copula model provides a multivariate dependency description for the on-site wind and wave-related environmental parameters. Two surrogate models, including the Kriging model and the artificial neural network (ANN), are implemented to efficiently predict the short-term fatigue damages at critical locations of the floating wind turbine. The proposed long-term fatigue damage assessment framework is accurate and suitable for evaluating structural long-term fatigue damages accumulated in a real environment especially when effects from more environmental parameters are to be considered. Based on surrogate models, sensitivity analyses are carried out to investigate the relative significance of each environmental parameter on short-term fatigue damages. In addition, uncertainties from short-term fatigue damages are also incorporated into the probabilistic fatigue evaluation framework to assess the accumulated long-term fatigue damages for a spar type floating wind turbine.
Domaine de référence : EMR
Auteur Li Xuan, Zhang Wei
Année de parution : 2020.
Mots-clés : Artificial neural network (ANN), C-vine copula, Fatigue damage assessment, Floating offshore wind turbine, Kriging model, Sensitivity analysis.
Type de document : Article de revue.
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The international regulation for the protection of the environment in the development of marine renewable energy in the EU

Résumé : Marine renewable energy (MRE) technologies have been fostered in the European Union (EU) due to their potential contribution to achieving the EU’s climate objectives and the decarbonization of the energy system. However, their development can pose severe environmental risks to marine ecosystems. Hence, the EU requires environmental protection and sustainable growth for the development of MRE in maritime spaces under the sovereignty or jurisdiction of EU Member States. This article analyses the main international law instruments for the protection of the environment against the impacts associated with the deployment of MRE in the EU. It argues that the international legal framework is theoretically capable of protecting the environment against the impacts of MRE, but that it needs to be further developed and specified to ensure exhaustive protection. However, it also highlights the important role of this framework to provide a basis for developing the framework at the EU secondary law level.
Domaine de référence : EMR
Auteur Soria‐Rodríguez Carlos
Année de parution : 2020.
Type de document : Article de revue.
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Platform Stabilization of Floating Offshore Wind Turbines by Artificial Muscle based Active Mooring Line Force Control

Résumé : The floating offshore wind turbine (FOWT) presents under-actuation challenge for controls in terms of platform stability, power regulation and increased structural loads, which demands for simple, low-cost, low-power and high-bandwidth actuation concepts. In this paper, an active mooring line force control (AMLFC) strategy is proposed based on a novel thermally-actuated fishing line artificial muscle (FLAM) actuator. The proposed FLAM actuator consist of multiple bundles of twisted nylon fishing lines, which is added to the junction between the mooring lines and platform bars of FOWT with tensioned-leg platform (TLP). A simulation model of the FLAM actuator is developed in Simulink, along with an interface to the mooring line model of TLP-FOWT in NREL's FAST. The dynamic model of the FLAM actuator is obtained with ANSYS simulation, and a control oriented model is obtained for the FOWT platform motion. A linear quadratic regulator (LQR) is implemented for the FLAM based AMLFC. Simulations are performed on the 5MW WindPACT model for one Region-2 and one Region-3 scenario. Simulation results show that, with mild power consumption, the proposed strategy can significantly reduce the platform roll motion and the tower-base side-side bending loads without little impact on the rotor speed and power output.
Domaine de référence : EMR
Auteur Wu Zhongyou, Li Yaoyu
Année de parution : 2020.
Mots-clés : active mooring line force control, Actuators, artificial muscle, Blades, Floating wind turbine, Heating systems, Load modeling, load reduction, Muscles, platform motion stabilization, Rotors, Wind turbines.
Type de document : Article de revue.
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Does wind speed effects performance and cost of energy ? A case study of wind farm

Résumé : Purpose The rapid rising of renewable energy sources particularly wind energy cannot be ignored. The numerical increase in wind energy farms throughout the world is the best example. The purpose of this paper is to assess the basic question of whether wind characteristics affect the performance and cost of energy. The importance of this question cannot be ruled out while comparing renewable energy to a conventional form of energy more specifically especially for the developing country where the cost of energy is very high. Design/methodology/approach The research design of this paper is consists of an assessment of local wind characteristics of the wind farm site using Weibull k and c parameters. The performance model is used to assess the performance of the wind turbine (WT) corresponding to local wind characteristics. The wind correlation with WT in terms of changing wind speed has been assessed to quantify the effects of wind speed on the WT behavior and failure of WT components. Similarly, the power curve of WT is assessed and compared with the International Electrotechnical Commission standards 61400-12-2. The WT power coefficient and tip speed ratio corresponding to wind speed is also investigated. The energy volume and cost of energy lost model is used to determine the cost and volume loss of energy/kWh of the wind farm. Findings The findings of practical wind farms showed that the wind conditions of the site are showing a strong tendency that can be determined from the results of Weibull k and c parameters. The k and c parameters are observed to be 3.44 and 9.16 m/s, respectively, for a period of a year. The standard deviation is observed to be 2.56 for a period of a year. WT shows the efficient behavior can be obtained from the power coefficient and tip speed of WT at different wind speeds. Also, wind farm observation showed that to be some increasing wind speed cause of based WT component failures. The results of energy volume and cost/kWh assessment showed that the major portion of energy volume and cost of energy is lost owing to network, voltage dip and frequency surge, electrical and mechanical components failures. Originality/value Generally, it can be concluded that the WTs are now able to cope with variable wind speeds. However, the results of this paper are showing that WT performance and availability decreased due to increased wind speeds. It can also be a reason to decreased volume and increase the cost of energy/kWh.
Domaine de référence : EMR
Auteur Hulio Zahid Hussain, Jiang Wei
Année de parution : 2020.
Mots-clés : Availability, Cost comparison, Cost of energy, Energy production, Performance, Performance model, Weibull parameters, Wind characteristics.
Type de document : Article de revue.
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Coupled modeling and structural vibration control for floating offshore wind turbine

Résumé : The tremendous wind-wave excitations bring about structural vibrations, which would have adverse influences on the power generation efficiency of the spar floating offshore wind turbine (FOWT). Therefore, two tuned mass dampers (TMDs) are installed in the platform and nacelle of the spar FOWT to control the vibration responses of the structure. The aero-hydro-servo-structure-TMDs coupling kinetics model of 16-degree-of-freedom (DOF) is firstly established for the spar FOWT. The correctness of the coupled model is then verified through comparing with OC3 project of FAST developed by the National Renewable Energy Laboratory (NREL). Subsequently, the TMDs stiffness and damping coefficients are optimized in constraints of the TMDs mass and stroke. Furthermore, the vibration reduction effects of TMDs are studied in the free decay state and wind-wave load cases, respectively. The simulation results demonstrate that the platform TMD can effectively reduce the platform pitch (PFPI) movement and low frequency vibration of the tower top fore-aft (TTFA) deflection, while the nacelle TMD is effective for the high frequency vibration of the TTFA deflection. Thus, the TMDs can control the structural vibration responses of spar FOWTs.
Domaine de référence : EMR
Auteur Yang J. J., He E. M.
Année de parution : 2020.
Mots-clés : Coupled model, Dynamic response, FOWT, Lagrange's equations, TMD, Vibration reduction.
Type de document : Article de revue.
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General Criteria for Optimal Site Selection for the Installation of Ocean Thermal Energy Conversion (OTEC) Plants in the Mexican Pacific

Résumé : The purpose of this chapter is to provide an assessment of the resource potential for ocean thermal energy conversion (OTEC) in the Mexican Pacific Ocean (MPO). Research methodology adopted in this study is a combination of geographic information system (GIS), to identify the most promising site in the MPO for OTEC deployment. Site selection criteria rely on conditions such as distance to cold water pumping, bathymetry, thermal difference (not less than 20°C), and social and environmental aspects. Finally we concluded that sites located in the states of Guerrero and Oaxaca have the highest potential of the entire MPO, although there are other areas in the states of Baja California Sur, Nayarit, or Michoacan that might have some interest for OTEC technology.
Domaine de référence : EMR
Auteur Huante Alejandro García, Cueto Yandy Rodríguez, Ruiz Erika Paola Garduño, Contreras Ricardo Efraín Hernández
Année de parution : 2020.
Type de document : Article de revue.
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Research and Development Activities of Ocean Thermal Energy-Driven Development in Malaysia

Résumé : The search for potential investors in the conversion of ocean thermal energy to power or hydrogen, and its spinoff projects in Malaysia and the region, continues. In the meantime, several pre-feasibility studies have been completed for selected sites, including that of Pulau Layang-Layang and Pulau Kalumpang (Sabah, Malaysia); Timor-Leste, and off Pulau Weh (Aceh, Indonesia). Various research projects have been completed such as the conversion of solar-thermal to the chilled-water system; the cooling of tropical soils for the culture of temperate crops; the design of offshore structure off the continental slope; hydrogen fuel production and distribution, deep seawater properties to reduce obesity, cholesterol and blood pressure; and the legal-institutional framework for the development of ocean thermal energy conversion. UTM Ocean Thermal Energy Centre (UTM OTEC) has entered into the Collaborative Research Agreement with the Institute of Ocean Energy of Saga University (Japan) to undertake joint research for the development of an experimental rig that introduces a hybrid system with stainless steel heat exchanger. Other aspects of this joint research would include a new design for 3 kW turbine, the introduction of nano-working fluids, the eDNA of intake waters, and improved productivity in the culture of high-value marine produce and products.
Domaine de référence : EMR
Auteur Jaafar A. Bakar, Husain Mohd Khairi Abu, Ariffin Azrin
Année de parution : 2020.
Type de document : Article de revue.
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Numerical Study on Initial Laying Process of Submarine Cables for Wave Energy Booster Station in Real Sea States

Résumé : Hu, J.; Li, Z., and Zhang, Y., 2020. Numerical study on initial laying process of submarine cables for wave energy booster station in real sea states. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 60-66. Coconut Creek (Florida), ISSN 0749-0208.Based on real sea conditions of the national wave energy demonstration site in Wanshan sea area of Zhuhai City, China, some numerical experiments are carried out to simulate the submarine cables initial laying process of the Wave Energy Booster Station in this demonstration site. The numerical model is established with the Orcaflex software employed. The motion response of laying ship and the hydrodynamic characteristics of submarine cables are simulated here under three sea conditions, i.e. usual waves, waves with current combined and possible extreme waves. Research results show that the tension and curvature of the cable are large under the condition for wave direction perpendicular to the ship axial direction, which is a relatively bad sea condition. The current also has some influences on the submarine cable laying, and the maximum effective tension of cable produced by the combined wave-current action is 1.35 times that of cable with the wave action alone. When extreme waves appear, pitch, heave and heave acceleration of the laying ship and tension of the cable ends increases obviously. And the variation of effective tension at both cable ends can reach 1.67 times that of cable ends under usual random waves. The numerical model and research results in this paper can provide some guidance for the research and construction of the cable laying of booster stations for marine renewable energy power plants in real sea conditions.
Domaine de référence : EMR
Auteur Hu Jinpeng, Li Zhenglin, Zhang Yunqiu
Année de parution : 2020.
Type de document : Article de revue.
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A Numerical Prediction on the Transient Response of a Spar-type Floating Offshore Wind Turbine in Freak Waves

Résumé : Simulations are conducted in time domain to investigate the dynamic response of a Spar-type floating offshore wind turbine under the freak wave scenarios. Towards this end, a coupled aero-hydro-mooring in-house numerical code is adopted to perform the simulations. The methodology includes a blade-element-momentum model for simulating the aerodynamic loads, a nonlinear model for simulating the hydrodynamic loads, a nonlinear restoring model of Spar buoy and a nonlinear algorithm for simulating the mooring cables. The OC3 Hywind Spar-type FOWT is adopted as an example to study the dynamic response under the freak wave conditions, meanwhile the time series of freak waves are generated using the random frequency components selection phase modulation method. The motion of platform, the tension applied on the mooring lines and the power generation performance are documented in several cases. According to the simulations, it is indicated that when a freak wave acts on the FOWT, the transient motion of the FOWT is induced in all DOFs, as well as the produced power decreases rapidly. Furthermore, the impact of freak wave parameters on the motion of FOWT is discussed.
Domaine de référence : EMR
Auteur Li Yan, Qu Xiaoqi, Liu Liqin, Xie Peng, Yin Tianchang, Tang Yougang
Année de parution : 2020.
Type de document : Article de revue.
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• Biocorrosion icone-flux-rss

Methods and Systems for Management of Corrosion in Building Pipe Circulation Systems

Résumé : A building pipe network system and method of operating a building pipe network inerting system includes providing an inert gas source, at least one of a closed loop water chiller system and a fire protection system. The closed loop water chiller system has a compressor, a condenser, an evaporator, a first pipe network, and a first vent in fluid connection with the first pipe network. The fire protection system has a source of pressurized water, a second pipe network fluidly connected with the source of pressurized water, a sprinkler fluidly connected with the second pipe network, and a second vent in fluid connection with the second pipe network. There is also a first fluid connection between the first pipe network and the nitrogen source, and a second fluid connection between the second pipe network and the nitrogen source. An inert gas source, such as a nitrogen gas source, is connected to at least one of, and preferably all, the present pipe networks. Inert gas is supplied from the inert gas source to the pipe network. Water is supplied to the pipe network thereby substantially filling the pipe network with water and compressing the inert gas in the pipe network.
Domaine de référence : Biocorrosion
Auteur Kochelek Jeffrey T.
Année de parution : 2020.
Type de document : Brevet.
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IMPACTS OF MAN-MADE STRUCTURES ON MARINE BIODIVERSITY AND SPECIES STATUS - NATIVE & NON- NATIVE SPECIES

Résumé : Sulfate‐reducing bacteria (SRB) are one of the main reasons for the accelerated corrosion of steel. Cathodic polarization has been reported as an effective and economic method against marine corrosion, including microbiologically induced corrosion. However, the interaction between cathodic polarization and microbial activity has not been well defined. In this study, a fluorine‐doped tin oxide electrode is used to study the effect of cathodic current on SRB cells. Fluorescence microscopy results clearly show that the attachment degree of SRB is dependent on the electric quantity and current intensity. The large electric quantity and high cathodic current (400 mA/m2 × 30  h) can effectively inhibit bacterial attachment and subsequent biofilm formation. Furthermore, the effect of cathodic potential on the corrosion behavior of X65 steel in the presence of SRB is systematically investigated. Results show that the impressed charges, the increase of pH, and the formation of calcareous deposits on the electrode surface at the cathodic potential of −1,050 mV/SCE inhibit the attachment of SRB. In turn, the presence of SRB also interferes with the electrochemical reactions that occur during the polarization process, thus increasing the cathodic current. The interaction between SRB‐induced corrosion and the process of preventing corrosion by various cathodic potentials is discussed.
Domaine de référence : Biocorrosion
Auteur Pawaskar Sonali
Année de parution : 2020.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Methods and Systems for Management of Corrosion in Building Pipe Circulation Systems

Résumé : A building pipe network system and method of operating a building pipe network inerting system includes providing an inert gas source, at least one of a closed loop water chiller system and a fire protection system. The closed loop water chiller system has a compressor, a condenser, an evaporator, a first pipe network, and a first vent in fluid connection with the first pipe network. The fire protection system has a source of pressurized water, a second pipe network fluidly connected with the source of pressurized water, a sprinkler fluidly connected with the second pipe network, and a second vent in fluid connection with the second pipe network. There is also a first fluid connection between the first pipe network and the nitrogen source, and a second fluid connection between the second pipe network and the nitrogen source. An inert gas source, such as a nitrogen gas source, is connected to at least one of, and preferably all, the present pipe networks. Inert gas is supplied from the inert gas source to the pipe network. Water is supplied to the pipe network thereby substantially filling the pipe network with water and compressing the inert gas in the pipe network.
Domaine de référence : Biocorrosion
Auteur Kochelek Jeffrey T.
Année de parution : 2020.
Type de document : Brevet.
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Characterization of the biofilm grown on 304L stainless steel in urban wastewaters : extracellular polymeric substances (EPS) and bacterial consortia

Résumé : Characterization of the biofilm growing on stainless steel (SS) in untreated (UTUWW) and treated (TUWW) urban wastewaters was performed. In both media, the first phase of biofilm growth was aerobic, when the genera Caldimonas, Caulobacter, Terriglobus and Edaphobacter (iron oxidizing bacteria [IOB]) and the genera Bacillus, Sulfurimonas, Syntrophobacter and Desulfobacter (sulfur oxidizing bacteria [SOB]) were identified. In the second phase, established after immersion for 7 days, the high amount of EPS inhibited the access of oxygen and promoted the growth of anaerobic bacteria, which were the genus Shewanella (iron-reducing bacterium [IRB]) and the genera Desulfovirga, Desulfovibrio, Desulfuromusa, Desulfococcus, and Desulfosarcina (sulfate-reducing bacteria [SRB]). Electrochemical measurements showed that in the first stage, the aerobic bacteria and the high amount of EPS delayed the cathodic reduction of oxygen. However, in the second stage, EPS and the anaerobic bacteria promoted anodic dissolution.
Domaine de référence : Biocorrosion
Auteur Ziadi Islem, El-Bassi Leila, Bousselmi Latifa, Akrout Hanene
Année de parution : 2020.
Mots-clés : Biocorrosion, corrosive consortia, EPS, iron-bacteria, sulphate-bacteria.
Type de document : Article de revue.
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Stress corrosion cracking of rockbolts : An in-situ testing approach

Résumé : Premature failure of rockbolts due to stress corrosion cracking (SCC) is an unresolved global issue in underground structures, particularly underground mines. To date, SCC of rockbolts has been produced in laboratory-based studies under laboratory conditions, however no attempt to produce SCC in-situ in actual underground coal mine conditions has previously been made. In this study, an innovative testing methodology was used in which a rockbolt coupon was developed with multiple stressed sections. The test coupon could be placed in-situ within a borehole in an underground mine, exposing it to the borehole environment, the surrounding rock strata and the groundwater. In-situ coupons were made from both 1355 and HSAC840 grade rockbolt steels and installed within a typical rockbolted horizon where known SCC failure of rockbolts had occurred. SCC occurred in the 1355 grade in-situ coupons, but not in the HSAC840 grade ones despite service failures of HSAC840 rockbolts having occurred in the same underground mine. The difference in behaviour of the HSAC840 coupons and in-service rockbolts is most likely due to different stress regimes acting on the coupons and the rockbolts. Localised corrosion was observed on both steels although analysis of the groundwater indicated that it had low corrosivity. Microbiological analysis showed that a range of bacteria known to be involved in corrosion were present on the rockbolt coupons and in the underground environment. This suggested that the occurrence of localised corrosion and SCC in low corrosivity groundwater could be due to the presence of microbial organisms, in particular, sulphate reducing bacteria. The results of this study provide detailed insights into the SCC of rockbolts in the underground environment. The method developed here can be used to study other reinforcement elements and stressed settings for stress corrosion cracking.
Domaine de référence : Biocorrosion
Auteur Craig Peter, Lamei Ramandi Hamed, Chen Honghao, Vandermaat Damon, Crosky Alan, Hagan Paul, Hebblewhite Bruce, Saydam Serkan
Année de parution : 2020.
Mots-clés : Hydrogen embrittlement, Rockbolt failure analysis, Stress corrosion cracking, Underground mines.
Type de document : Article de revue.
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Chapter 6 - Microbially influenced corrosion of container material

Résumé : Microbially influenced corrosion (MIC) has been recognized as a potential challenge for the safe performance of deep geological radioactive waste repositories. This chapter presents an introduction to the influences of microorganisms on corrosion processes of metal containers. The principles of biofilm development on metal surfaces, microorganisms involved in MIC, and the relevant conditions for metal-microbe interactions in repositories will be described. Particular emphasis is put on sulfate-reducing bacteria, one of the most critical microorganisms for MIC of waste containers, whether made of carbon steel, stainless steel, or copper. Finally, we present the results of a long-term study on carbon steel corrosion in deep natural groundwater containing sulfate-reducing bacteria to illustrate the impact of temperature on the formation of different biofilms and corrosion behavior.
Domaine de référence : Biocorrosion
Auteur Černoušek Tomáš, Ševců Alena, Shrestha Rojina, Steinová Jana, Kokinda Jakub, Vizelková Kateřina, Lloyd Jonathan R., Cherkouk Andrea
Année de parution : 2021.
Mots-clés : Biofilm, Container material, Deep geological repository, Radioactive waste, Sulfate-reducing bacteria.
Type de document : Chapitre de livre.
Source : Elsevier
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An integrated dynamic failure assessment model for offshore components under microbiologically influenced corrosion

Résumé : The microbiologically influenced corrosion (MIC) is a serious issue that should be considered for effective risk-based integrity management of offshore systems under MIC. This paper presents a proper methodology by using a hybrid Bayesian network (BN) and Markov process to predict the MIC rate, failure probability, and critical failure year of an internally corroded subsea pipeline. The BN model is developed to probabilistically obtain the MIC rate, considering the dynamic non-linearity and interdependency among vital input factors. The effects of the nonlinear interactions of various prominent factors are evaluated, and their degree of influence is explored. The Markov process is employed to predict the failure probability, critical failure year, and the time evolution MIC pit depth distribution using the predicted MIC rate as a transition intensity. The developed model is adaptive and captures the evolving impact of MIC. The proposed integrated methodology is tested on a case study, and the most critical parameters that influence the MIC rate and system failure are identified. The proposed approach would provide an early warning guide for a timely intervention to prevent total failure of corroded subsea pipelines and associated consequences.
Domaine de référence : Biocorrosion
Auteur Adumene Sidum, Adedigba Sunday, Khan Faisal, Zendehboudi Sohrab
Année de parution : 2020.
Mots-clés : Bayesian network, Failure assessment, Markov process, Microbiologically influenced corrosion, Pipeline failure probability, Pit depth.
Type de document : Article de revue.
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Failure analysis of a welded stainless-steel piping system with premature pitting caused by Microbiologically-Influenced Corrosion (MIC) after hydrostatic testing

Résumé : A failure analysis of welded pipes (ASTM A312 Grade TP 316L) in a water treatment plant was done and it is presented in this paper. The premature failure was detected by several water leakages caused by pitting corrosion three months after hydrostatic tests and before transferring the plant to the operator. The leakages were located near the bottom of the circumferential complete penetration butt welds of the entire piping system. The samples were analyzed using visual inspection, radiographic examination, optical emission spectrometry, ferrite number measurements, metallographic examination and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectrometry (EDS). The results showed that the corrosion rate was extremely high compared to other studies available in the literature for austenitic stainless steel and the pits were in the weld metal and the Heat Affected Zone (HAZ) of the circumferential welds. The lack or deficiency of a purging gas during the field welding generated heat-tinted zones around the welds. Visual inspection showed that the pits were preferentially located at heat-tinted zones and they have large sub-surface cavities. The SEM inspection confirmed the presence of sulfate-reducing bacteria and iron-oxidizing bacteria and revealed that the failure was caused by Microbiologically-Influenced Corrosion (MIC). The review of standards and codes used to perform hydrostatic testing of austenitic stainless-steel piping systems showed that the water used for hydrostatic tests should have been treated before testing or the surfaces should have been deeply drained and dried. The failure was caused by the raw water used during the hydro-testing since it was not fully drained from the piping system and remained stagnant leading to MIC.
Domaine de référence : Biocorrosion
Auteur Diego Bedoya-Zapata Álvaro, Mauricio Franco-Rendón Carlos, León-Henao Henry, Felipe Santa Juan, Enrique Giraldo Barrada Jorge
Année de parution : 2020.
Mots-clés : austenitic stainless steel, heat tint, hydrostatic testing, Microbiologically-Influenced Corrosion, welding.
Type de document : Article de revue.
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Etude des interactions bactéries-surfaces et des effets sur la passivation des aciers inoxydables

Résumé : Les aciers inoxydables doivent leur résistance à la corrosion à la formation d’une couche d’oxyde à leur surface, communément qualifiée de film passif, qui a une épaisseur de quelques nanomètres et se compose majoritairement d’oxydes et/ou d’hydroxydes de Fe(III) et de Cr(III). Cependant, dans des milieux agressifs, la stabilité de la couche d’oxyde peut être compromise, ce qui peut déclencher des phénomènes de corrosion (localisée ou généralisée). Par exemple, en présence de microorganismes, et plus particulièrement de bactéries, l’adhésion bactérienne et la formation d’un biofilm à la surface peut conduire à l’initiation et/ou à l’accélération des processus de corrosion : on parle alors de biocorrosion. Dans un premier temps, nous avons caractérisé la couche d’oxyde formée à la surface de l’acier inoxydable duplex 2304 par un couplage de techniques fines d’analyse des surfaces (XPS et ToF-SIMS). Nous avons notamment mis en évidence des différences concernant la composition chimique de la surface sur chacune des phases de l’alliage duplex. Dans un second temps, nous avons caractérisé la surface de l’alliage duplex au cours de l’adhésion de bactéries marines aérobies Pseudoalteromonas NCIMB 2021 en milieu marin par un couplage de techniques de caractérisation microscopiques (microscopie à épifluorescence, MEB et AFM), de techniques fines d’analyse des surfaces (XPS et ToF-SIMS) et de techniques électrochimiques (suivi du potentiel à l’abandon, courbes de polarisation anodiques et cathodiques). Nous avons notamment montré que la formation du biofilm s’accompagne de modifications de la couche d’oxyde.
Domaine de référence : Biocorrosion
Auteur Gardin Elise
Année de parution : 2018.
Type de document : Thèse.
Source : Université Paris sciences et lettres
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Direct and Indirect Evidence of the Microbially Induced Pitting Corrosion of Steel Structures in Humid Environments

Résumé : Corrosion is a severe problem for steel structures in humid environments. In particular, humidity usually triggers the surface adhesion of microorganisms, leading to microbiologically induced corrosion. This study aims to explore the effect of bacterial biofilm formation on the pitting corrosion of stainless steel. This research uses electrochemical methods to obtain indirect evidence of the pitting corrosion of steel. In addition, in order to obtain direct evidence of the pitting corrosion of stainless steel, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) were used to characterize the dimensional morphology of the stainless steel after pitting. It was shown that the bacterial adhesion increased with the pH and temperature, which significantly increased the surface roughness of the stainless steel. Electrochemical analysis revealed that the formation of biofilm greatly destroyed the oxide film of 304 SS and accelerated the corrosion of stainless steel by forming an oxygen concentration battery. SEM and AFM analyses showed cracks and dislocations on the surface of stainless steel underneath the attached bacteria, which suggested a direct role of biofilm in corrosion induction. The results presented here show that the bacterial biofilm formation on the steel surfaces significantly accelerated the corrosion and affected the pitting corrosion process of the steel structure.
Domaine de référence : Biocorrosion
Auteur Zhou Jingzhong, Sun Kuoteng, Huang Songqiang, He Xuemin, Hu Zhaowei, Li Wenge
Année de parution : 2020.
Mots-clés : AFM, electrochemical testing, microbiologically induced corrosion, pitting corrosion, SEM, steel structure.
Type de document : Article de revue.
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Accelerating effect of catalase on microbiologically influenced corrosion of 304 stainless steel by the halophilic archaeon Natronorubrum tibetense

Résumé : The role of metabolic catalase in microbiologically influenced corrosion (MIC) of 304 stainless steel by Natronorubrum tibetense was investigated. Under sterile condition, the catalase concentration in the culture medium had no effect on the corrosion of stainless steel. In contrast, the addition of catalase in the inoculated culture medium resulted in more severe pitting corrosion of stainless steel. The potentiodynamic polarization results demonstrated that catalase mainly promoted the cathodic process of MIC of the stainless steel. Scanning electrochemical microscopy (SECM) further confirmed the accelerating effect of catalase on the cathodic oxygen reduction reaction of MIC.
Domaine de référence : Biocorrosion
Auteur Qian Hongchang, Zhang Dawei, Cui Tianyu, Chang Weiwei, Cao Fahe, Du Cuiwei, Li Xiaogang
Année de parution : 2020.
Mots-clés : A. Microbiologically influenced corrosion, B. Stainless steels, C. Scanning electrochemical microscopy.
Type de document : Article de revue.
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Controlling Bacterial Biofilms

Résumé : Methods of controlling bacteria cells are disclosed. These methods comprise upregulating expression of a DVU2956 sigma 54-dependent enhancer-binding protein (EBP) in bacteria cells, resulting in (i) dispersing a biofilm of the cells or reducing biofilm formation by the cells, and/or (ii) reducing hydrogen sulfide formation by the cells. Further disclosed are methods of identifying compounds for controlling bacteria cells as in (i) and/or (ii) above. Polynucleotides and cells are disclosed that can optionally be used to practice compound identification methods.
Domaine de référence : Biocorrosion
Auteur Yin Bei, Wood Thomas K.
Année de parution : 2020.
Type de document : Brevet.
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The cathodic protection potential criteria : Evaluation of the evidence

Résumé : Recent publications have ascribed the mechanism of cathodic protection (CP) in soils to the development of passivity at the steel surface. This view has, in turn, prompted discussion on the need to re-evaluate the long-established criteria for protection. This paper presents a contribution to that discussion. It advances, or rather it restates, the proposition that neither immunity nor passivity is necessarily relevant. It argues that protection is simply a consequence of a potential-driven lowering of the anodic dissolution rate. However, it also emerges that elucidating any mechanism convincingly requires dependable field or laboratory data on the very low corrosion rates occurring on cathodically polarised specimens. A critical review of published data highlights a lack of reliability in this area.
Domaine de référence : Biocorrosion
Auteur Googan Chris
Année de parution : 2020.
Mots-clés : activation control, cathodic protection, electrode kinetics, microbiologically influenced corrosion, passivity, protection potential.
Type de document : Article de revue.
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Further results on the in situ anaerobic corrosion of carbon steel and copper in compacted bentonite exposed to natural Opalinus Clay porewater containing native microbial populations

Résumé : Since 2012, a long-term in situ corrosion experiment (IC-A) is being conducted in the Mont Terri Underground Research Laboratory in Switzerland to investigate the corrosion behaviour of candidate canister materials in conditions representative of the Swiss concept for the disposal of high-level waste and spent nuclear fuel. To date, carbon steel and various types of copper coatings have been retrieved after different exposure periods of up to 3 years, and characterised to establish the composition of the corrosion product, the morphology of the corroded surface, the nature of the interaction between the metal and the surrounding bentonite, and the microbial populations in the bentonite and surrounding porewater. For carbon steel specimens, a complex corrosion product was identified, consisting predominantly of magnetite. Much less alteration on either the metal or the bentonite was observed in the case of copper samples. Low average anaerobic corrosion rates were measured for carbon steel and a very modest amount of alteration was identified on copper. The density and the initial form of the bentonite had a small influence on the rate of corrosion, across all materials. This paper summarises the results of the experimental programme obtained to date and discusses the relationship observed between exposure time and the evolution of the metal–bentonite interface for both carbon steel and copper.
Domaine de référence : Biocorrosion
Auteur Reddy Bharti, Padovani Cristiano, Smart Nick R., Rance Andrew P., Cook Angus, Milodowski Antoni, Field Lorraine, Kemp Simon, Diomidis Nikitas
Année de parution : 2020.
Mots-clés : anaerobic, bentonite, carbon steel, copper, corrosion, microbial, radioactive waste.
Type de document : Article de revue.
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The anaerobic corrosion of candidate disposal canister materials in compacted bentonite exposed to natural granitic porewater containing native microbial populations

Résumé : The materials corrosion test (MaCoTe) is a long-term, multinational in situ corrosion experiment setup at the Grimsel Test Site, Switzerland. The experiment has been operating since 2014 with a focus on the corrosion behaviour of container materials for the disposal of high-level waste and spent nuclear fuel under conditions representing a granitic deep geological repository. The experiment consists of eight modules containing metal coupons and bentonite. Two of the modules, each with a different bentonite density, have been retrieved after 394 days of exposure and have been analysed using a range of techniques aimed at studying the corrosion behaviour of the metals and the mineralogical evolution of the bentonite. Weight loss measurements show that carbon steel had a relatively low average corrosion rate ( 2 µm year−1). Much lower average corrosion rates were measured for the various types of copper (0.13–0.32 µm year−1). No detectable corrosion was measured on stainless steel coupons. To date, no significant differences were observed in the corrosion behaviour and rate of the test metals in bentonite with different dry densities.
Domaine de référence : Biocorrosion
Auteur Reddy Bharti, Padovani Cristiano, Rance Andrew P., Smart Nick R., Cook Angus, Haynes Haydn M., Milodowski Antoni E., Field Lorraine P., Kemp Simon J., Martin Andrew, Diomidis Nikitas
Année de parution : 2020.
Mots-clés : anaerobic, bentonite, carbon steel, copper, corrosion, microbial, stainless steel, waste.
Type de document : Article de revue.
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CORROSION EFFECTS AND RATES IN OIL FIELDS STORAGE TANKS

Résumé : Corrosion is in essence a statistical effect governed by a number of variables. microscopic variations in a surface tend to cause different forms of corrosion and also variations in the corrosion rate over either a wide or small area (pitting). In these areas the simple assumption that corrosion rate is uniform across an area is unlikely to be accurate, and sample thickness measurements are unlikely to be representative of the whole component.
Domaine de référence : Biocorrosion
Auteur Osman Hassan, Ahmed Mohyedin, Mohammed M.A.A., Faris Mohamed H. M.
Année de parution : 2020.
Type de document : Article de revue.
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Combined effect of various elastic loading conditions and aerobic bacterium Pseudoalteromonas sp. on the corrosion behavior of S32750 super duplex stainless steel

Résumé : The combined effect of various elastic loading conditions and aerobic bacterium Pseudoalteromonas sp. on the corrosion behavior of S32750 super duplex stainless steel was investigated using electrochemical and surface analysis methods. Our results show that the combined influence is a nonlinear relationship between both parameters. The corrosion rate of S32750 SDSS under the combined effect is higher than the sum of the corrosion rate under elastic loading and under aerobic bacterium. The loading condition of σ0.5s in the presence of Pseudoalteromonas sp. caused to more harmful effects than the loading of σ0.75s with bacteria.
Domaine de référence : Biocorrosion
Auteur Guo Pushan, Moradi Masoumeh, Yang Lijing, Song Zhenlun
Année de parution : 2020.
Mots-clés : aerobic bacterium, elastic loading, microbiological corrosion, Super duplex stainless steel, surface corrosion, surface roughness.
Type de document : Article de revue.
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Microbial communities present on mooring chain steels with different copper contents and corrosion rates

Résumé : Copper has long been utilized as a disinfectant for bacteria, but its impact on microbial communities attached to the steel surface in seawater remains unknown. In the present study, 3 mooring chain steels of different copper contents are subjected to a 3-month marine field exposure, and the corrosion rate increases in the order of BR5 steel (without copper) < BR5CuH steel (0.8% copper) < BR5CuL steel (0.4% copper). The microbial community results show that copper introduction does not result in an obvious change in microbial quantity, but it alters the diversity, richness, and structure of microbial communities due to the variation in copper-resistance of different species. BR5CuH steel holds microbial communities with the highest percentage of some well-known corrosive microbes including sulfate-reducing bacteria, sulfuroxidizing bacteria, and iron-oxidizing bacteria, but possesses the lowest community diversity/richness owing to the toxicity of copper. The microbial community diversity/richness is stimulated by the low-copper content of BR5CuL steel, and this steel also carries an intermediate proportion of such corrosive bacteria. Both well-known corrosive bacteria and microbial community diversity/richness seem to be involved in the corrosion acceleration of copper-bearing mooring chain steels.
Domaine de référence : Biocorrosion
Auteur Wu Jiajia, Gao Jieyan, Zhang Dun, Tan Faqi, Yin Jiang, Wang Yu, Sun Yan, Li Ee
Année de parution : 2020.
Type de document : Article de revue.
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Biocorrosion resistance and biocompatibility of Mg-Al layered double hydroxide/poly(L-lactic acid) hybrid coating on magnesium alloy AZ31

Résumé : A Mg-Al layered double hydroxide (Mg-Al-LDH) coating was firstly synthesized via an in-situ steam coating growth method on the AZ31 Mg alloy, and then was modified with poly(L-lactic acid) (PLLA) via dipping and vacuum freeze-drying. The microstructure and composition of LDH/PLLA hybrid coating were analyzed by XRD, SEM, EDS and FT-IR. The biocorrosion behavior of hybrid coating was evaluated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and hydrogen evolution test in the Hank’s solution. The results showed that LDH/PLLA coatings exhibited a much dense layer compared to the unmodified Mg-Al-LDH coating with unobvious boundary between PLLA and LDH coatings. The corrosion current density of the LDH/PLLA-10 hybrid coating decreased three orders of magnitude in comparison to its substrate. It was proven that the existence of the PLLA coating further prolonged the service life of the Mg-Al-LDH coating. What’s more, the MTT assay and live/dead staining showed that the LDH/PLLA-10 coating had good biocompatibility for Mouse NIH3T3 fibroblasts. The formation mechanism and the anti-corrosion mechanism of hybrid coatings were proposed.
Domaine de référence : Biocorrosion
Auteur Sun Xiang, Yao Qing-Song, Li Yu-Chao, Zhang Fen, Zeng Rong-Chang, Zou Yu-Hong, Li Shuo-Qi
Année de parution : 2020.
Type de document : Article de revue.
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Study of biofilm-influenced corrosion on X80 pipeline steel by a nitrate-reducing bacterium, Bacillus cereus, in artificial Beijing soil

Résumé : The biofilm of Bacillus cereus on the surface of X80 pipeline steel was investigated from forming to shedding. Based on the observed biofilm morphology and pit analysis, it was found that B. cereus biofilm could stimulate X80 pipeline steel pitting corrosion, which was attributed to the nitrate reduction of bacteria beneath the biofilm. Electrochemical measurements and general corrosion rate results showed that B. cereus biofilm can better accelerate X80 pipeline steel corrosion compared to sterile solutions. Interestingly, the results also showed that thick biofilms had a slight tendency to inhibit the general corrosion process compared with its formation and exfoliation, which was confirmed by scanning Kelvin probe. The corrosion rate of X80 pipeline steel in artificial Beijing soil is closely related to the state of the biofilm, and nitrate reducing bacteria accelerates the occurrence of pits. The corresponding corrosion mechanisms are proposed.
Domaine de référence : Biocorrosion
Auteur Liu Bo, Sun Meihui, Lu Fangyuan, Du Cuiwei, Li Xiaogang
Année de parution : 2021.
Mots-clés : Biological cathode, Heterogeneous biofilm, Soil environment, X80 pipeline steel.
Type de document : Article de revue.
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Microbial Induced Corrosion and Industrial Economy

Résumé : This chapter deals with deleterious effect on industrial machinery and other material structure due to Microbial Induced Corrosion. Corrosion, due to only chemicals, weakens the material strength prematurely and thus results in unscheduled shutdown of plants, catastrophic failure pf machinery, leakage of chemicals etc. This needs maintenance of machinery or its replacement. Other factors are also involved which together results in extra expenditure on industry to keep the system operational. This is Corrosion cost and it affects the economy of industrial production. Similar effect is also observed with MIC. The chapter discusses various aspects related to failure of machinery and the extent to which MIC is observed in various industries or structures etc. Although, it has not been possible to systematically evaluate damage due to MIC due to reasons e.g. (i) difficult to identify whether failure is due to corrosion or MIC or (ii) combining the effect of biocorrosion with biofouling etc. Still effort has been made to put an estimated cost due to MIC on the basis of data present in literature on MIC. An account of various industries and their various sections experiencing MIC has been given which helps in appreciating the deleterious effect of MIC on machinery, vehicles and structures etc.
Domaine de référence : Biocorrosion
Auteur Singh Ajay K., Singh Ajay K.
Année de parution : 2020.
Mots-clés : Corrosion cost, Cost estimate, Direct cost, Indirect cost due to MIC, Industry sectors.
Type de document : Chapitre de livre.
Source : Springer
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Mitigation of Microbial Induced Corrosion

Résumé : After deliberating about basics related to corrosion, MIC, different types of bacteria, and their metabolic reactions taking part in the process of corrosion of metals, it is obvious to talk about the ways and means for mitigating MIC. This chapter deals with this aspect in two parts, the first part dealing with the conventional/currently undergoing techniques while the second part dealing with newer/green technology approach for MIC mitigation. One can refer it to MICI, i.e., microbial induced corrosion inhibition. Thus, it deals with not only inhibition of MIC but also microbial induced inhibition of chemical corrosion. First category of methods includes (i) cleaning, (ii) usage of biocides, (iii) coating, and (iv) cathodic protection. Conventionally, mostly adopted procedure to control MIC is by use of biocides. However, biocides pollute the environment, some of them are carcinogenic, and some even corrode material of construction. Consequently, newer methods being suggested have to be environment-friendly. Approach adopted for controlling MIC includes usage of microorganisms which affect (i) production of protective biofilm, (ii) in-situ production of antimicrobials, and (iii) usage of extracellular polymeric substances (EPSs).
Domaine de référence : Biocorrosion
Auteur Singh Ajay K., Singh Ajay K.
Année de parution : 2020.
Mots-clés : Antimicrobials, Biocides, Cleaning, Coating, EPS, Protective biofilm.
Type de document : Chapitre de livre.
Source : Springer
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Microbial Induced Corrosion and Related Theories

Résumé : After introducing corrosion, the next step obviously is to learn about Microbial Induced Corrosion (MIC). Fundamentals of MIC are same as those for corrosion. But a basic difference between the two is in terms of significant role played by microorganisms in corroding the materials. By way of various metabolic reactions and deposition of biofilms, the microbes change the chemistry of the environment which help in inducing corrosion or accelerate corrosion reaction rates. However, as you shall see, while going through the later chapters of the book, that microbes not only induce corrosion but some inhibit corrosion. This chapter thereafter discusses various aspects related to MIC such as biofilm formation, bioenergetics, on the basis of electrochemical fundamentals, leading to initiation of MIC, Biocatalytic Reduction, Extra cellular electron transfer, carbon source starvation etc. The chapter then discusses MIC due to some important bacteria e.g. sulfate reducing bacteria (SRB), Iron oxidizing bacteria (IOB), Nitrate reducing bacteria (NRB), Fungi, Algae, Archaea.
Domaine de référence : Biocorrosion
Auteur Singh Ajay K., Singh Ajay K.
Année de parution : 2020.
Mots-clés : Biocatalytic reduction, Bioenergetics, Biofilm, Extracellular electron transfer, Metabolic reaction.
Type de document : Chapitre de livre.
Source : Springer
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Experimental Details and Strategies to Control Corrosion

Résumé : This chapter is divided into three parts. First two parts discuss about experimental details related to experiments which may be required to do in investigation on MIC. First of these is microbiology work, e.g., isolation of bacteria from natural resources, studying the growth cycle of bacteria, and biofilm characterization, and second of these is related to investigating corrosion due to bacteria. In this later case, details have been discussed about surface preparation of original and corroded metal samples, preparation of test solution, corrosion estimation test, e.g., immersion test, electrochemical test, analytical tests, e.g., XRD, FTIR, SEM, and ESCA. The third part deals with the strategies to control MIC. This part discusses about corrosion-causing bacteria, e.g., sulfate-reducing bacteria (SRB), iron-oxidizing bacteria (IOB), metal-reducing bacteria, and acid-producing bacteria, and the details involved which are responsible for MIC. Afterward, in this chapter, details about the bacteria which mitigate MIC or corrosion have been dealt. This part deals with several different ways in which microbial induced corrosion inhibition can be practiced using bacteria. Thus, microbial inhibition has been discussed (i) by removal of oxygen, (ii) by inhibiting growth of corrosion-causing bacteria through production of antimicrobials, and (iii) by using microbes which produce protective layers.
Domaine de référence : Biocorrosion
Auteur Singh Ajay K., Singh Ajay K.
Année de parution : 2020.
Mots-clés : Analytical tests, Biofilm, Corrosion tests, Growth cycle, Inhibition, Metal surface.
Type de document : Chapitre de livre.
Source : Springer
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Etude des interactions bactéries-surfaces et des effets sur la passivation des aciers inoxydables

Résumé : Les aciers inoxydables doivent leur résistance à la corrosion à la formation d’une couche d’oxyde à leur surface, communément qualifiée de film passif, qui a une épaisseur de quelques nanomètres et se compose majoritairement d’oxydes et/ou d’hydroxydes de Fe(III) et de Cr(III). Cependant, dans des milieux agressifs, la stabilité de la couche d’oxyde peut être compromise, ce qui peut déclencher des phénomènes de corrosion (localisée ou généralisée). Par exemple, en présence de microorganismes, et plus particulièrement de bactéries, l’adhésion bactérienne et la formation d’un biofilm à la surface peut conduire à l’initiation et/ou à l’accélération des processus de corrosion : on parle alors de biocorrosion. Dans un premier temps, nous avons caractérisé la couche d’oxyde formée à la surface de l’acier inoxydable duplex 2304 par un couplage de techniques fines d’analyse des surfaces (XPS et ToF-SIMS). Nous avons notamment mis en évidence des différences concernant la composition chimique de la surface sur chacune des phases de l’alliage duplex. Dans un second temps, nous avons caractérisé la surface de l’alliage duplex au cours de l’adhésion de bactéries marines aérobies Pseudoalteromonas NCIMB 2021 en milieu marin par un couplage de techniques de caractérisation microscopiques (microscopie à épifluorescence, MEB et AFM), de techniques fines d’analyse des surfaces (XPS et ToF-SIMS) et de techniques électrochimiques (suivi du potentiel à l’abandon, courbes de polarisation anodiques et cathodiques). Nous avons notamment montré que la formation du biofilm s’accompagne de modifications de la couche d’oxyde.
Domaine de référence : Biocorrosion
Auteur Gardin Elise
Année de parution : 2020.
Type de document : Thèse.
Source : Université Paris sciences et lettres
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Charge-reversal surfactant antibiotic material for reducing microbial corrosion in petroleum exploitation and transportation

Résumé : The corrosions caused by sulfate-reducing bacteria (SRB) are serious problems in petroleum exploitation and transportation, which can lead to safety problems, environmental pollutions, and economic losses. Here, a charge-reversal surfactant antibiotic material N-dodecyl-1-carboxylic acid-1-cyclohexenyl-2-carboxamide (C12N-DCA) is designed and synthesized. C12N-DCA is a negatively charged surfactant, which cannot be adsorbed by soil and rock in a large amount. Therefore, it can reach the "lesion location", with enough concentration. After being hydrolyzed and charge reversed under the acceleration of H2S produced by SRB, C12N-DCA becomes a positively charged surfactant dodecane ammonium salt to kill SRB. Through a simulating experiment, it is found that C12N-DCA can reach the SRB inhibition ratio of almost 100%, and it can reduce iron corrosion by 88%. Such an antibiotic material or its homologs may be added to the chemical flooding fluids, killing SRB during petroleum exploitation and reducing the SRB-induced corrosion in the petroleum exploitation and transportation.
Domaine de référence : Biocorrosion
Auteur Zeng Lingda, Chang Yincheng, Wu Yukun, Yang Jinpeng, Xu Jiang-Fei, Zhang Xi
Année de parution : 2020.
Type de document : Article de revue.
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Review and analysis of microbiologically influenced corrosion : the chemical environment in oil and gas facilities

Résumé : Microbiologically influenced corrosion (MIC) is a complex phenomenon requiring integrated knowledge of multiple disciplines to better manage and mitigate impacts. The chemical environment (e.g. produced water, soured oil) plays an important role in MIC. Chemical reactions and phase changes due to temperature, pressure, pH and to a lesser extent salinity, impact microbial activities which in turn influences the surrounding chemical environment leading to corrosion. The chemical–microbial interactions complicate the understanding of chemical species transformation and partitioning behaviour in gas, water and oil and subsequent impact on corrosion. In this paper, a review of the complex chemical transformations of chemical species resulting from biotic and abiotic processes are presented. These chemical species can have growth, inhibitory or synergistic effects on microbial activities causing MIC. Microbial activities are found to overlap with chemical/electrochemical processes leading to corrosion. The interaction between chemical environment, environmental factors, electrochemical and microbial processes has been explained with examples from the literature, to understand the contributory effects on MIC. This study will inform further investigation on the chemical environment impacting MIC and model development.
Domaine de référence : Biocorrosion
Auteur Ibrahim Abdulhaqq, Hawboldt Kelly, Bottaro Christina, Khan Faisal
Année de parution : 2018.
Mots-clés : chemical environment, chemical species, environmental factors, microbial activities, Microbiologically influenced corrosion.
Type de document : Article de revue.
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Modeling microbial sulfate reduction and the consequences for corrosion of copper canisters

Résumé : The copper sulfide model (CSM) is a one-dimensional reactive transport code for predicting the evolution of the corrosion behavior of a copper canister in a deep geological repository. Here, the CSM has been extended to simulate the microbial reduction of sulfate in the repository and the consequences for corrosion of the canister. Organotrophic and chemotrophic sulfate reduction are represented by Monod kinetics, along with the dissolution of solid organic matter and gypsum as sources of nutrient and an electron acceptor, respectively. Siderite dissolution in the buffer and tunnel backfill materials acts as a source of Fe(II), which can then precipitate the microbially produced sulfide as mackinawite. Results are presented for a simulation representing the expected evolution of the corrosion behavior and repository environment and for a series of sensitivity analyses designed to identify the most important processes in the overall reaction scheme.
Domaine de référence : Biocorrosion
Auteur King Fraser, Kolář Miroslav, Puigdomenech Ignasi, Pitkänen Petteri, Lilja Christina
Année de parution : 2020.
Mots-clés : copper, KBS-3, reactive transport modeling, safety assessment, sulfate-reducing bacteria.
Type de document : Article de revue.
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Bacterial community analysis of biofilm on API 5LX carbon steel in an oil reservoir environment

Résumé : This study aimed to characterize the biofilm microbial community that causes corrosion of API 5LX carbon steel. API 5LX carbon steel coupons were incubated with raw produced water collected from two oil reservoir stations or filter-sterilized produced water. Biofilm 16S rRNA amplicon sequencing revealed that the bacterial community present in the biofilm was dominated by Proteobacteria, including Marinobacter hydrocarbonoclaustics and Marinobacter alkaliphilus. Electrochemical analysis such as impedance and polarization results indicated that Proteobacteria biofilm accelerated corrosion by ~ twofold (2.1 ± 0.61 mm/years) or ~ fourfold (~ 3.7 ± 0.42 mm/years) when compared to the control treatment (0.95 ± 0.1 mm/years). Scanning electron and atomic force microscopy revealed the presence of a thick biofilm and pitting corrosion. X-ray diffraction revealed higher amounts of the corrosion products Fe2O3, γ-FeOOH, and α-FeOOH, and confirmed that the microbial biofilm strongly oxidized the iron and contributed to the acceleration of corrosion of carbon metal API 5LX.
Domaine de référence : Biocorrosion
Auteur Elumalai Punniyakotti, AlSalhi Mohamad S., Mehariya Sanjeet, Karthikeyan Obulisamy Parthiba, Devanesan Sandhanasamy, Parthipan Punniyakotti, Rajasekar Aruliah
Année de parution : 2020.
Mots-clés : Biocorrosion, Biotic system, MiSeq analysis, Proteobacteria, Weight loss.
Type de document : Article de revue.
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The roles of biomolecules in corrosion induction and inhibition of corrosion : a possible insight

Résumé : Biofilms cause huge economic loss to the industry through corrosion. A deeper understanding of how biofilms form, develop and interact will help to decipher their roles in promoting and inhibiting corrosion, thus in controlling it. The present review explores most mechanisms of biofilm development and maintenance with particular emphasis on the roles of the biomolecules characteristic of biofilms, including exopolysaccharides (EPSs), proteins/enzymes, lipids, DNA and other metabolites in the corrosion process. These biomolecules play a significant role in the electron transfer process resulting in corrosion induction and inhibition. Microbial attachment, biofilm formation, the EPS matrix and both positive and negative effects by specific biofilm-forming genes all play roles in the electron transfer process. The current review describes these roles in detail. Although challenging to understand and control, the potential of biomolecules in the corrosion process is huge, and the coming decades will witness significant progress in the field. As well as discussing the technologies available for investigating corrosion induction and its inhibition, we also point to gaps in this knowledge.
Domaine de référence : Biocorrosion
Auteur Karn Santosh Kumar, Bhambri Anne, Jenkinson Ian R., Duan Jizhou, Kumar Awanish
Année de parution : 2020.
Type de document : Article de revue.
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Study on Corrosion Behavior of X80 Steel under Stripping Coating by Sulfate Reducing Bacteria

Résumé : Background: At present, microorganism has been considered as important factors that threaten to buried pipelines with disbonded coatings. Aiming at the problem of unknown corrosion mechanism of sulfate-reducing bacteria (SRB), a series of studies have been carried out in this paper. Spectrophotometer and fluorescent labeling technology are used to study the growth and attachment of SRB in the simulated soil solution. The electrochemical behavior of X80 pipeline steel with or without SRB was researched by electrochemical methods such as open circuit potential, dynamic potential polarization curve, and electrochemical impedance spectroscopy. The microscopic morphology of the corrosion products on the surface of the sample was observed with a scanning electron microscope (SEM), and the element content of the corrosion products on the surface of the sample after corrosion was observed using X-ray energy spectrum (EDS) analysis.
Domaine de référence : Biocorrosion
Auteur Cui Yan-Yu, Qin Yong-Xiang, Ding Qing-Miao, Gao Yu-Ning
Année de parution : 2020.
Type de document : Article de revue.
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Microbially influenced corrosion : Towards an interdisciplinary perspective on mechanisms

Résumé : A perspective is provided on mechanisms for microbially influenced corrosion by sulfate-reducing bacteria and metal-oxidizing bacteria. The authors discuss the confusion introduced by cross-disciplinary discussions of MIC mechanisms and the divergent terminologies used by microbiologists and electrochemists, e.g. “anaerobic” and “direct electron transfer.” Examination of the cathodic depolarization theory for corrosion of carbon steel by sulfate-reducing bacteria suggests that the theory cannot explain the observations. Stainless steels containing <20% chromium are vulnerable to pitting in the presence of iron and manganese oxides produced by iron- and manganese-oxidizing bacteria, respectively. However, mechanisms for pitting differ between the two oxides. In all cases, understanding mechanisms for microbially influenced corrosion must consider the environment, i.e., the composition of the electrolyte, in addition to the vulnerability of the material in the presence of putative microorganisms. Significant opportunity exists for more integrated approaches to interdisciplinary research and open discourse.
Domaine de référence : Biocorrosion
Auteur Little Brenda J., Hinks Jamie, Blackwood Daniel J.
Année de parution : 2020.
Mots-clés : Cathodic depolarization, Direct electron transfer, Mechanisms, Metal-oxidizing bacteria, Microbially influenced corrosion, Sulfate-reducing bacteria.
Type de document : Article de revue.
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Iron corrosion induced by the hyperthermophilic sulfate-reducing archaeon Archaeoglobus fulgidus at 70 °C

Résumé : This work assessed the role of the hyperthermophilic sulfate-reducing archaeon, Archaeoglobus fulgidus in anaerobic iron corrosion, at 70 °C, in the presence and the absence of lactate as energy source. Experiments performed with A. fulgidus planktonic cells, displayed their capacity to form a biofilm on an iron coupon and exhibited their biocorrosive activity. A. fulgidus was shown to cause indirect corrosion by producing sulfide while oxidizing lactate. Furthermore, the archaeon could grow lithotrophically by using elemental iron as a mineral energy source. Under these latter conditions, A. fulgidus formed chimneys enhancing the direct corrosion process. Moreover, physiological modifications occurred under these conditions notably highlighting the probable use of CO2 instead of sulfate as a terminal electron acceptor to produce acetate similarly to homoacetogens. All together, these results illustrate the metabolic versatility and hence the importance of this hyperthermophilic archaeon in microbial induced corrosion (MIC).
Domaine de référence : Biocorrosion
Auteur Amin Ali Oulfat, Aragon Emmanuel, Fahs Armand, Davidson Sylvain, Ollivier Bernard, Hirschler-Rea Agnès
Année de parution : 2020.
Mots-clés : Biofilm, Chimneys, Hyperthermophile, Iron biocorrosion, Sulfate-reducing archaeon.
Type de document : Article de revue.
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Biocorrosion of copper metal by Aspergillus niger

Résumé : Several geoactive fungi were investigated for their biocorrosion impact on metallic copper, to further understanding of the potential roles that fungi may have in the biotransformation of such substrate, and the mechanisms involved. Copper metal showed little toxicity and test fungi were able to grow in direct or indirect contact with copper and to colonize copper sheet. A. niger was able to biodeteriorate copper metal through proton- and ligand-mediated dissolution mechanisms, leading to significant mass loss and surface etching. The formation of a secondary copper oxalate (moolooite) biomineral crust together with cuprite deposition lead to alteration of surface topography and visual appearance, highlighting the significance of oxalate excretion in effecting fungal metal biotransformations. The metal transforming influence of fungal colonization may have some implications for biodeterioration, protection and preservation of cultural relics and artefacts as well as certain components of the built environment.
Domaine de référence : Biocorrosion
Auteur Zhao Jiayue, Csetenyi Laszlo, Gadd Geoffrey Michael
Année de parution : 2020.
Mots-clés : Biocorrosion, Biomineralization, Copper, Oxalate.
Type de document : Article de revue.
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Effects of Minor Sr Addition on Biocorrosion and Stress Corrosion Cracking of As-Cast Mg-4Zn Alloys

Résumé : Microstructure, biocorrosion, and stress corrosion cracking (SCC) behavior of as-cast Mg-4Zn-xSr alloys (x ≤ 0.4, in mass%) are studied by scanning electron microscopy, immersion testing, slow strain rate tensile testing, etc. A minor Sr addition (≤0.2%) in Mg-4Zn alloy can reduce the average corrosion rate and the corrosion current density in Hank’s solution, resulting from grain refinement, dispersion of the smaller secondary phase particles, and the more-protective corrosion product film. Thus, a minor Sr addition (≤0.2%) can improve both strength and plasticity of the Mg-4Zn alloy without increasing the SCC susceptibility, and the Mg-4Zn-0.1Sr alloy exhibits the best comprehensive properties.
Domaine de référence : Biocorrosion
Auteur Gong Xiaole, Chen Jihua, Yan Hongge, Xia Weijun, Su Bin, Yu Zonglin, Yin Hui
Année de parution : 2019.
Type de document : Article de revue.
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Texte intégral

Domaine de référence : Biocorrosion
Année de parution : 0.
Type de document : Pièce jointe.
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Distinct Temporal Succession of Bacterial Communities in Early Marine Biofilms in a Portuguese Atlantic Port

Résumé : Marine biofilms are known to influence the corrosion of metal surfaces in the marine environment. Despite some recent research, the succession of bacterial communities colonizing artificial surfaces remains uncharacterized in some temporal settings. More specifically, it is not fully known if bacterial colonizers of artificial surfaces are similar or distinct in the different seasons of the year. In particular the study of early biofilms, in which the bacterial cells communities first adhere to artificial surfaces, are crucial for the development of the subsequent biofilm communities. In this work, we used amplicon-based NGS (next-generation sequencing) and universal 16S rRNA bacterial primers to characterize the early biofilm bacterial communities growing on 316 L stainless steel surfaces in a Northern Portugal port. Sampling spanned 30-day periods in two distinct seasons (spring and winter). Biofilm communities growing in steel surfaces covered with an anti-corrosion paint and planktonic communities from the same location were also characterized. Our results demonstrated that distinct temporal patterns were observed in the sampled seasons. Specifically, a significantly higher abundance of Gammaproteobacteria and Mollicutes was found on the first days of biofilm growth in spring (day 1 to day 4) and a higher abundance of Alphaproteobacteria during the same days of biofilm growth in winter. In the last sampled day (day 30), the spring biofilms significantly shifted toward a dominance of photoautotrophic groups (mostly diatoms) and were also colonized by some macrofouling communities, something not observed during the winter sampling. Our results revealed that bacterial composition in the biofilms was particularly affected by the sampled day of the specific season, more so than the overall effect of the season or overall sampling day of both seasons. Additionally, the application of a non-fouling-release anti-corrosion paint in the steel plates resulted in a significantly lower diversity compared with plates without paint, but this was only observed during spring. We suggest that temporal succession of marine biofilm communities should be taken in consideration for future antifouling/anti-biofilm applications.
Domaine de référence : Biocorrosion
Auteur Antunes Jorge T., Sousa António G. G., Azevedo Joana, Rego Adriana, Leão Pedro N., Vasconcelos Vitor
Année de parution : 2020.
Mots-clés : marine biofilms, marine corrosion, marine fouling, pioneer bacteria, steel surfaces, temporal succession.
Type de document : Article de revue.
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Oil field microorganisms cause highly localized corrosion on chemically inhibited carbon steel

Résumé : Carbon steel pipelines, a means for crude oil transportation, occasionally experience highly localized perforation caused by microorganisms. While microorganisms grown in laboratory culture tend to corrode steel specimens unevenly, they rarely inflict a corrosion morphology consistent with that of pipelines, where centimetre-sized corrosion features are randomly distributed within vast stretches of otherwise pristine metal surface. In this study, we observed that corrosion inhibitors (CIs), widely used for the control of acid gas (H2 S, CO2 ) corrosion in oil fields, also affect microbial growth and activity. Inhibited carbon steel resisted biofilm formation and underwent negligible corrosion (< 0.002 mm Fe0 year-1 ), despite 15 months of exposure to oil field waters harbouring a diverse microbiome. In contrast, physical scavenging of CI in these waters led to severe and highly localized corrosion (up to 0.93 mm Fe0 year-1 ) underneath biofilms dominated by methanogenic archaea and sulfate-reducing bacteria. A sharp decline in CI concentration, as well as its active components, quaternary ammonium compounds (QACs), correlated with microbial sulfidogenesis. CIs are ubiquitously present in oil field waters and play an underappreciated role in microbial corrosion mitigation. Physical and biological scavenging of CIs may create local differences in steel inhibition effectiveness and thus result in highly localized corrosion.
Domaine de référence : Biocorrosion
Auteur Mand Jaspreet, Enning Dennis
Année de parution : 2020.
Type de document : Article de revue.
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Potential shift of bacterial community structure and corrosion-related bacteria in drinking water distribution pipeline driven by water source switching

Résumé : As a result of pollution in the present water sources, cities have been forced to utilize cleaner water sources. There are few reports regarding the potential shift of bacterial community structure driven by water source switching, especially that of corrosion-related bacteria. Three types of finished water were used for simulation, the polluted source water from the Qiantang and Dongtiaoxi Rivers (China) was replaced by cleaner water from Qiandao Lake (China). Here, we discussed the transition effects through three simulated reactors. The bacterial characteristics were identified using the high-throughput sequencing and heterotrophic plate count method. It was observed that the level of culturable bacteria declined by 2–3 orders of magnitude after water source switching. The bacterial community released from the pipeline reactor was significantly different under different finished water, and it exhibited large variation at the genus level. Porphyrobacter (58.2%) and Phreatobacter (14.5%) clearly replaced Novosphingobium, Aquabacterium, and Cupriavidus as new dominant genera in system A, which could be attributed to the lower carbon and nitrogen content of the new water source. Although corrosion-inhibiting bacteria decreased after switching, they still maintained dominant in three reactors (6.6%, 15.9%, and 19.7%). Furthermore, potential opportunistic pathogens such as Sphingomonas were detected. Our study shows that after transition to a high quality water source, the total culturable bacteria released was in a downtrend, which leads to a great reduction in the risk of bacterial leakage in the produced drinking water.
Domaine de référence : Biocorrosion
Auteur Hu Yue, Dong Ding, Wan Kun, Chen Chao, Yu Xin, Lin Huirong
Année de parution : 2020.
Type de document : Article de revue.
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Degradation Assessment and Failure Prevention of Pipeline Systems

Domaine de référence : Biocorrosion
Auteur Bolzon Gabriella
Année de parution : 2020.
Type de document : Livre.
Source : Springer Nature
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Plus de références Biocorrosion


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IMPACTS OF MAN-MADE STRUCTURES ON MARINE BIODIVERSITY AND SPECIES STATUS - NATIVE & NON- NATIVE SPECIES

Résumé : Coastal environments are exposed to anthropogenic activities such as frequent marine traffic and restructuring, i.e., addition, removal or replacing with man-made structures. Although maritime shipping and coastal infrastructures provide socio-economic benefits, they both cause varied perturbations to marine ecosystems. The ports and marinas receiving a high frequency of international vessels, act as ‘hot-spots’ for marine invasions. The disturbed and modified habitats found in harbours and ports provide opportunities for non-native species to settle due to their competitive traits. Once established, the non-native species may spread to neighbouring habitats, thereby modifying the adjacent natural environment, its biodiversity, ecosystem structure and functioning. Up to 70% of coastlines around the world have now been modified and is expected to rise in future. New bioinvasions are still being reported even with various biosecurity and management approaches across the globe. It is essential to understand the potential factors influencing the bioinvasions to have effective biosecurity measures and management plans. The overall aim of this thesis is to determine the influence of man-made structures on the marine biodiversity and presumptive fitness of native and non-native species on these structures. This thesis investigates ports and harbours as man-made environments, their impacts on marine biodiversity and the species status – native, non-native and cryptogenic, and the factors facilitating the spread of non-native species.
Domaine de référence : Antifouling
Auteur Pawaskar Sonali
Année de parution : 2020.
Type de document : Article de revue.
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The Use of a UVC Lamp Incorporated With an ROV to Prevent Biofouling : A Proof-of-Concept Study

Résumé : Abstract A proof-of-concept study was designed to investigate using an Ultraviolet C (UVC) lamp mounted on a hull-crawling remotely operated vehicle (ROV) to prevent biofouling on a ship hull. A wheeled cart with a UVC lamp was built to expose two large test panels to UVC. The test panels were coated with an ablative copper antifouling and a silicone fouling release coating, and these were immersed in seawater at Port Canaveral, Florida. Three exposure frequencies (once a week, twice a week, and three times a week) and two dosages (8 and 16 s of UVC exposure) were tested. UVC was effective at preventing biofilm growth during the first 2 weeks of UVC treatment but was unable to prevent increased fouling growth as time progressed. It appears that an increase in UVC intensity and duration of exposure would be needed to prevent fouling growth especially during high-fouling seasons or that UVC exposure would need to be combined with another fouling prevention practice, such as mechanical wiping, to be more effective.
Domaine de référence : Antifouling
Auteur Braga Cierra, Hunsucker Kelli, Erdogan Caglar, Gardner Harrison, Swain Geoffrey
Année de parution : 2020.
Mots-clés : biofouling, grooming, marine coatings, ROV, UVC.
Type de document : Article de revue.
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Review of Underwater Ship Hull Cleaning Technologies

Résumé : This paper presents a comprehensive review and analysis of ship hull cleaning technologies. Various cleaning methods and devices applied to dry-dock cleaning and underwater cleaning are introduced in detail, including rotary brushes, high-pressure and cavitation water jet technology, ultrasonic technology, and laser cleaning technology. The application of underwater robot technology in ship cleaning not only frees divers from engaging in heavy work but also creates safe and efficient industrial products. Damage to the underlying coating of the ship caused by the underwater cleaning operation can be minimized by optimizing the working process of the underwater cleaning robot. With regard to the adhesion technology mainly used in underwater robots, an overview of recent developments in permanent magnet and electromagnetic adhesion, negative pressure force adhesion, thrust force adhesion, and biologically inspired adhesion is provided. Through the analysis and comparison of current underwater robot products, this paper predicts that major changes in the application of artificial intelligence and multirobot cooperation, as well as optimization and combination of various technologies in underwater cleaning robots, could be expected to further lead to breakthroughs in developing next-generation robots for underwater cleaning.
Domaine de référence : Antifouling
Auteur Song Changhui, Cui Weicheng
Année de parution : 2020.
Type de document : Article de revue.
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Instantaneous flow characteristics associated with long-term marine macrofouling growth and suppression

Résumé : It is well-established that the growth of biofouling organisms such as algae, barnacles, and mussels is a consequence of both biological and hydrodynamic constraints. Several studies have examined how instantaneous flow fields at the scale of a marine larva affect the initial settling and attachment of biofouling organisms over a period of minutes. However, it is unclear whether a connection exists between the instantaneous flow field and long-term macrofouling survival and growth, or indeed if it is applicable at an ecosystem-wide level. Seven-week field studies were analyzed in conjunction with instantaneous PIV flow fields in order to build a bridge between hydrodynamics and long-term biological growth. The results indicate that flows resulting in long-term, multi-species biofouling prevention share certain characteristics, providing a potential framework for understanding flow fields that successfully inhibit biofouling growth
Domaine de référence : Antifouling
Année de parution : 2020.
Type de document : Article de colloque.
Source : American Physical Society
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Fabrication of biomimetic slippery liquid-infused porous surface on 5086 aluminum alloy with excellent antifouling performance

Résumé : Biofouling triggers extensive research in ship tribology. Antifouling technology has garnered great attention as a solution for biofouling; thus, biomimetic lubricant-infused surfaces are developed as alternatives to superhydrophobic surfaces. In this study, we developed slippery liquid-infused porous surfaces (SLIPS) by infusing perfluoropolyether oil into porous anodic aluminum oxide (AAO) surfaces using a vacuum impregnation device. The oil settled firmly in the AAO surfaces owing to the strong capillary forces in the pores, thus forming a lubricating layer with a low contact angle hysteresis and long-term slippery condition. SLIPS exhibited an excellent antifouling performance by reducing 98.4% of Phaeodactylum tricornutum. The coefficient of biofilm formed by the microorganisms was also investigated. The results confirmed that the lubricating layer impeded the formation of biofilm. This research provides valuable information for the fabrication of SLIPS and its antifouling mechanism.
Domaine de référence : Antifouling
Auteur Yang Zongcheng, He Xiaoyan, Chang Jiangfan, Bai Xiuqin, Cao Pan, Yuan Chengqing
Année de parution : 2020.
Mots-clés : aluminum alloy, antifouling, biofilm, lubricant-infused surfaces, nanostructures.
Type de document : Article de revue.
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Sustainable anti-biofouling and drag reduction of covalent mucilage coatings

Résumé : Biofilms contaminate a wide variety of infrastructure elements, systems, and devices. Toxic paints containing biocides provide an effective antifouling tool. However, most of them have been banned internationally because of their unacceptable environmental impacts. To resolve this problem, the development of environmentally friendly coating method is necessary. Inspired by various functions of mucus or mucilage produced by algae and other marine organisms, we developed the multi-functional mucilage coating method with both drag reduction and anti-biofouling effect. In this study, carboxymethyl cellulose (CMC) was coated on the slide glass, and various functional polymers such as mPEG-amine, chitosan, and alginate were covalently attached on the CMC coated surfaces. We measured the slip length of CMC and mPEG coated surfaces with the best anti-biofouling effect. CMC coated surface had no slip effect, while the mPEG-amine coated surface showed slip effect. In this study, we demonstrated that our coating process generates a stable mucilage coating with anti-biofouling and drag reduction properties. The proposed covalent mucilage coating would be available in various industrial fields that require sustainable anti-biofouling and drag reduction.
Domaine de référence : Antifouling
Année de parution : 2020.
Type de document : Article de colloque.
Source : American Physical Society
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Metal resistance genes enrichment in marine biofilm communities selected by biocide-containing surfaces in temperate and tropical coastal environments

Résumé : Microorganisms able to form biofilms in marine ecosystems are selected depending on immersed surfaces and environmental conditions. Cell attachment directly on toxic surfaces like antifouling coatings suggests a selection of tolerant (or resistant) organisms with characteristics conferring adaptive advantages. We investigated if environment would drive metal resistance gene abundance in biofilms on artificial surfaces. Biofilms were sampled from three surfaces (a PVC reference and two antifouling coatings) deployed in three coastal waters with dissimilar characteristics: The Mediterranean Sea (Toulon) and Atlantic (Lorient) and Indian (Reunion) Oceans. The two coatings differed in metals composition, either Cu thiocyanate and Zn pyrithione (A3) or Cu2O (Hy). Metal resistance genes (MRG) specific to copper (cusA, copA, cueO) or other metals (czcA and pbrT) were monitored with qPCR in parallel to the microbial community using 16S rRNA gene metabarcoding. A lower α-diversity on A3 or Hy than on PVC was observed independent on the site. Weighted Unifrac suggested segregation of communities primarily by surface, with lower site effect. Metacoder log2 fold change ratio and LeFSe discrimination suggested Marinobacter to be specific of Hy and Altererythrobacter, Erythrobacter and Sphingorhabdus of A3. Likewise, the relative abundance of MRG (MRG/bacterial 16S rRNA) varied between surfaces and sites. A3 presented the greatest relative abundances for cusA, cueO and czcA. The latter could only be amplified from A3 communities, except at Toulon. Hy surface presented the highest relative abundance for copA, specifically at Lorient. These relative abundances were correlated with LeFSe discriminant taxa. Dasania correlated positively with all MRG except cueO. Marinobacter found in greater abundance in Hy biofilm communities correlated with the highest abundances of copA and Roseovarius with czcA. These results prove the selection of specific communities with abilities to tolerate metallic biocides forming biofilms over antifouling surfaces, and the secondary but significant influence of local environmental factors.
Domaine de référence : Antifouling
Auteur Catao Elisa C. P., Gallois Nicolas, Fay Fabyenne, Misson Benjamin, Jean-François B. R. I. A. N. D.
Année de parution : 2020.
Mots-clés : anthropogenic effect, antifouling surface, Complex communities, copper tolerance.
Type de document : Article de revue.
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Phidianidine A and Synthetic Analogues as Naturally Inspired Marine Antifoulants

Résumé : Stationary and slow-moving marine organisms regularly employ a natural product chemical defense to prevent being colonized by marine micro- and macroorganisms. While these natural antifoulants can be structurally diverse, they often display highly conserved chemistries and physicochemical properties, suggesting a natural marine antifouling pharmacophore. In our current report, we investigate the marine natural product phidianidine A, which displays several chemical properties found in highly potent marine antifoulants. Phidianidine A and synthetic analogues were screened against the settlement and metamorphosis of Amphibalanus improvisus cyprids, and several of the compounds displayed inhibitory activities at low micromolar concentrations with IC50 values down to 0.7 μg/mL observed. The settlement study highlights that phidianidine A is a potent natural antifoulant and that the scaffold can be tuned to generate simpler and improved synthetic analogues. The bioactivity is closely linked to the size of the compound and to its basicity. The study also illustrates that active analogues can be prepared in the absence of the natural constrained 1,2,4-oxadiazole ring. A synthetic lead analogue of phidianidine A was incorporated in a coating and included in antifouling field trials, where it was shown that the coating induced potent inhibition of marine bacteria and microalgae settlement.
Domaine de référence : Antifouling
Auteur Labriere Christophe, Elumalai Vijayaragavan, Staffansson Jannie, Cervin Gunnar, Le Norcy Tiffany, Denardou Hugo, Réhel Karine, Moodie Lindon W. K., Hellio Claire, Pavia Henrik, Hansen Jørn H., Svenson Johan
Année de parution : 2020.
Type de document : Article de revue.
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Inhibition of sulfate-reducing bacteria influenced corrosion on hydrophobic poly(dimethylsiloxane) coatings

Résumé : Sulfate-reducing bacteria (SRB) has been pointed out as one of the causative agents of microbial induced corrosion in the marine environment. To address this problem, novel strategies are being experimented as against the earlier methods which have been banned due to their toxic effects on useful aquatic lives. Thus, the aim of this study was to investigate the effect of non-toxic perfluorodecyltrichlorosilane (PFDTS) on resistance of hydrophobic poly(dimethylsiloxane)/phosphoric acid-treated zinc oxide (PDMS/PA-treated ZnO) coatings to SRB-induced biofouling and corrosion. The surface features of the coatings before and after exposure to SRB/NaCl solution were analyzed by scanning electron microscopy (SEM). Wettability of the coatings before and after exposure was also measured. The interaction of SRB with the coatings was investigated by FTIR spectroscopy. The resistance performance of the modified coatings against SRB-induced corrosion was monitored by electrochemical impedance spectroscopy (EIS). The EIS measurements revealed that 0.20 g PFDTS-based coating displayed highest corrosion resistance with impedance modulus of 6.301 x 10(10) after 15 d of exposure to SRB/NaCl medium. The results were corroborated by surface and chemical interaction analyses, and thus, indicate that 0.20 g PFDTS-modified PDMS/PA-treated ZnO coating has potentials for excellent SRB-induced corrosion resistance and anti-biofouling performance. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
Domaine de référence : Antifouling
Auteur Arukalam Innocent O., Njoku C. N., Yang Lihui, Hou Baorong, Li Ying
Année de parution : 2020.
Type de document : Article de revue.
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The effect of cathodic polarization on the corrosion behavior of X65 steel in seawater containing sulfate-reducing bacteria

Résumé : Sulfate-reducing bacteria (SRB) are one of the main reasons for the accelerated corrosion of steel. Cathodic polarization has been reported as an effective and economic method against marine corrosion, including microbiologically induced corrosion. However, the interaction between cathodic polarization and microbial activity has not been well defined. In this study, a fluorine-doped tin oxide electrode is used to study the effect of cathodic current on SRB cells. Fluorescence microscopy results clearly show that the attachment degree of SRB is dependent on the electric quantity and current intensity. The large electric quantity and high cathodic current (400 mA/m2 × 30 h) can effectively inhibit bacterial attachment and subsequent biofilm formation. Furthermore, the effect of cathodic potential on the corrosion behavior of X65 steel in the presence of SRB is systematically investigated. Results show that the impressed charges, the increase of pH, and the formation of calcareous deposits on the electrode surface at the cathodic potential of −1,050 mV/SCE inhibit the attachment of SRB. In turn, the presence of SRB also interferes with the electrochemical reactions that occur during the polarization process, thus increasing the cathodic current. The interaction between SRB-induced corrosion and the process of preventing corrosion by various cathodic potentials is discussed.
Domaine de référence : Antifouling
Auteur Lv Meiying, Li Xia, Du Min
Année de parution : 2020.
Mots-clés : cathodic polarization, microbiologically induced corrosion, seawater, sulfate-reducing bacteria, X65 steel.
Type de document : Article de revue.
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Microfluidic Encapsulation of Hydrophobic Antifouling Biocides in Calcium Alginate Hydrogels for Controllable Release

Résumé : Microencapsulation of biocides is used in long-life antifouling coating paints for marine applications and building materials. Here, we report the microfluidic production of calcium alginate (Ca-alginate) hydrogel particles to modulate the release of the encapsulated drug Irgarol (N-cyclopropyl-N′-(1,1-dimethylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine), which is a hydrophobic and specifically phytotoxic antifoulant that inhibits photosystem II in aquatic plant species. We first encapsulated the drug inside the highly spherical Ca-alginate hydrogels of an average diameter ∼160 μm with a coefficient of variation of less than 4% and an average roundness of more than 0.96. The release speeds of the encapsulated and nonencapsulated drugs in pure water were measured separately by ultraviolet–visible spectroscopy. A stable and controllable release rate of the loaded drug was achieved by hydrophilic encapsulation. In addition, cellulose fibers were incorporated to enhance the mechanical strength of the hydrogels. Finally, the antifouling effect of the encapsulated drug was demonstrated using water grass (Bacopa monnieri).
Domaine de référence : Antifouling
Auteur Liu Yingzhe, Nisisako Takasi
Année de parution : 2020.
Type de document : Article de revue.
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Inhibition of Marine Biofouling with Degradable Copolymer

Résumé : Hou, X.; Sun, W.; Luo, Q.; Zhang, S., Huang, S., 2020. Inhibition of marine biofouling with degradable copolymer. In: Yang, D.F. and Wang, H. (eds.), Recent Advances in Marine Geology and Environmental Oceanography. Journal of Coastal Research, Special Issue No. 108, pp. 178–182. Coconut Creek (Florida), ISSN 0749-0208.Degradable copolymers are promising materials for marine antibiofouling as the resource and environmental problems become more and more serious. Degradable copolymer poly(-caprolactone-co-tert-butyl methacrylate) was synthesized with organic catalyst. The presence of the poly(-caprolactone) entries increases the erosion rates and reduce the swelling of the polymer film in the meantime. Poly(tert-butyl methacrylate) segments enhance the adhesion of the copolymer. Our study indicates that as the ester units in the backbone increase, the degradation rate increases but the swelling decreases in seawater. The degradation is controlled by the polymer composition or the molar ratio of the ester units. Marine field tests demonstrate that the degradable copolymers show good antibiofouling performance.
Domaine de référence : Antifouling
Auteur Hou Xinran, Sun Wei, Luo Qi, Zhang Siyu, Huang Shaowen
Année de parution : 2020.
Type de document : Article de revue.
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Effect of ultrasonic frequency on the bacterial community structure during biofouling formation in microfiltration membrane bioreactors for wastewater treatment

Résumé : Biofouling significantly reduces the performance efficiency of membrane bioreactors due to the colonization and accumulation of a matrix of microorganisms. In order to investigate the effect of ultrasonic frequency on biofilm formation and bacterial ecology at different frequencies, four microfiltration membrane modules were subjected at 0, 20, 30 and 40 kHz in pilot-scales. The results of massive parallel sequencing showed that the application of ultrasonic frequency significantly affected the bacterial population in biofouling and modifies the species richness even at low frequency. This research reveals that the application of ultrasonic frequencies avoids the colonization of Acinetobacter genus, which is considered an initial colonizer of biofouling and clogging in the submerged membrane reactor, fact that caused problems in full-scale wastewater treatment plant. The promotion of Gordonia genus was observed during the application of any ultrasounds frequencies (20,30 and 40 Hz). The compositional statistics data exposed the similarity of bacterial communities under medium-high ultrasonic frequency, while those great distances were found in both low and no-ultrasounds frequencies apply. These results suggest that the application of ultrasounds in membrane bioreactor for treating wastewater could be effective in the potential reduction of biofouling formation in order to improve the to improve the useful life of this system with short periods of application of ultrasound.
Domaine de référence : Antifouling
Auteur Rodríguez-Calvo Alfonso, Gonzalez-Lopez Jesus, Ruiz Luz Marina, Gómez-Nieto Miguel Ángel, Muñoz-Palazon Barbara
Année de parution : 2020.
Mots-clés : Bacterial population, Biofouling, Membrane bioreactor (MBR), Oligotypes, Ultrasounds.
Type de document : Article de revue.
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Engineered topographies and hydrodynamics in relation to biofouling control—a review

Résumé : Biofouling, the unwanted growth of microorganisms on submerged surfaces, has appeared as a significant impediment for underwater structures, water vessels, and medical devices. For fixing the biofouling issue, modification of the submerged surface is being experimented as a non-toxic approach worldwide. This technique necessitated altering the surface topography and roughness and developing a surface with a nano- to micro-structured pattern. The main objective of this study is to review the recent advancements in surface modification and hydrodynamic analysis concerning biofouling control. This study described the occurrence of the biofouling process, techniques suitable for biofouling control, and current state of research advancements comprehensively. Different biofilms under various hydrodynamic conditions have also been outlined in this study. Scenarios of biomimetic surfaces and underwater super-hydrophobicity, locomotion of microorganisms, nano- and micro-hydrodynamics on various surfaces around microorganisms, and material stiffness were explained thoroughly. The review also documented the approaches to inhibit the initial settlement of microorganisms and prolong the subsequent biofilm formation process for patterned surfaces. Though it is well documented that biofouling can be controlled to various degrees with different nano- and micro-structured patterned surfaces, the understanding of the underlying mechanism is still imprecise. Therefore, this review strived to present the possibilities of implementing the patterned surfaces as a physical deterrent against the settlement of fouling organisms and developing an active microfluidic environment to inhibit the initial bacterial settlement process. In general, microtopography equivalent to that of bacterial cells influences attachment via hydrodynamics, topography-induced cell placement, and air-entrapment, whereas nanotopography influences physicochemical forces through macromolecular conditioning.
Domaine de référence : Antifouling
Auteur Halder Partha, Hossain Nazia, Pramanik Biplob Kumar, Bhuiyan Muhammed A.
Année de parution : 2020.
Type de document : Article de revue.
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Methods and Coatings for Protecting Surfaces from Bio-Fouling Species

Résumé : Methods of protecting a submerged surface from biofouling animal organisms include applying a first biologically active inner polymer layer on a surface, impregnated with at least one first biologically active agent that kills a juvenile stage of a biofouling animal organism. A second biologically active outer polymer layer is applied on the first biologically active inner polymer layer, impregnated with at least one second biologically active agent that inhibits a larval stage of the biofouling animal organism from attaching to the second biologically active outer polymer layer. The second biologically active outer polymer layer includes a friction-reducing additive selected from the group consisting of silicone powder, PTFE powder, molybdenum disulfide powder, graphene nano-platelets, graphene oxide, and fluorinated graphene powder.
Domaine de référence : Antifouling
Auteur Phillips Reed E., Mellott James M.
Année de parution : 2020.
Type de document : Brevet.
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Invasive ascidians : How predators reduce their dominance in artificial structures in cold temperate areas

Résumé : Artificial structures can provide suitable space for invasive species through a colonisable surface and refuge against predators. Besides several physical factors, invasive species can present different colonization success and dominance on structures that are connected to the sea floor (i.e. fixed) compared to structures that are suspended, depending on the differential predation pressure that affect both structures. Benthic and nektonic predators can reach fouling communities on fixed structures, while only nektonic predators can affect communities growing on suspended structures, depending on the distance to the sea floor. Only few studies tested both communities of predators at the same time in different artificial structures. In this study, we evaluated the effect of benthic and nektonic predators on the cover, composition and diversity on fouling communities and on the dominance of invasive ascidians on these communities, in two different types of artificial structures. We performed an experiment in the port area of Puerto Madryn (Southwestern Atlantic, Argentina) to compare the fouling community development between fixed and suspended structures and among different predator exclusion treatments. Results showed that benthic predators exerted a higher predation pressure than nektonic predators on the cover, composition and diversity of the fouling communities. In the absence of benthic predators, and even where nektonic predators were not excluded, communities were greatly dominated by two invasive ascidians, Ascidiella aspersa (Müller, 1776) and Ciona robusta Hoshino and Tokioka, 1967. Our results suggest that in this type of cold temperate ports, fouling organisms find refuge from benthic predators growing on suspended structures, where nektonic predators exert low predation pressure. We propose that, since benthic predators in temperate latitudes have an essential role decreasing invasive ascidians dominance and the cover of fouling communities, future studies should consider both predator communities, i.e. nektonic and benthic, in experimental designs performed to test biotic resistance and predation pressure.
Domaine de référence : Antifouling
Auteur Giachetti Clara B., Battini Nicolás, Castro Karen L., Schwindt Evangelina
Année de parution : 2020.
Mots-clés : Biotic resistance, Fouling communities, Predation pressure, Southwestern Atlantic.
Type de document : Article de revue.
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A Review on Invasive Species in Marine Biofouling

Résumé : Biofouling has become worldwide threat in the recent years. Scientists’ researching on biofouling is on peak aboard. There are organisms which colonize the underwater surfaces of ships such as spores of algae, barnacles, seaweeds, etc. which uses manifold array of biological glues to provide adhesion which is the result of biofouling. Invasive species hold world threat because of ships that introduce them the foreign environment through ballast waters and ship hulls. Sea trade expansion lead broad pathway for invasive species and promoted devastation of other native species. The ships struck with biofouling which travel over long distances, raises the content of CO2 release to 14-31%. This increases the concentration of greenhouse gases which make invasive species deplete and finally vanish away. Invasive plant species are the key initiators of global change. Certain chemicals and protein coatings have come into light to resist the adhesion of various biofouling species. This review focuses on various effects of invasive species in marine biofouling and the eco-friendly ways to eradicate them.
Domaine de référence : Antifouling
Auteur Shevalkar Maithili, Mishra Akanksha, Meenambiga S. S.
Année de parution : 2020.
Type de document : Article de revue.
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Prevention of Biofouling

Résumé : SummaryBiofouling is one of the key problems that many technical systems face. It weighs down ships, clogs filtration modules for water treatment and causes hygiene problems in clinical environments. At the Fraunhofer Institute for Microstructure of Materials and Systems IMWS, material science solutions have been developed to prevent the adhesion of foulants. An electrically conductive coating system applied to ships keeps the surfaces free of fouling effectively for an extended time. Thin hydrophilic layers on the components of filtration modules reduce the adsorption of microorganisms and can thus contribute to increasing efficiency and energy saving.
Domaine de référence : Antifouling
Auteur Wehrspohn Ralf B., Hirsch Ulrike, Neugebauer Reimund
Année de parution : 2020.
Type de document : Chapitre de livre.
Source : Springer
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Design and optimization of a water jet-based biomimetic antifouling model for marine structures

Résumé : Marine structures, such as ship hulls and offshore platforms, are basic elements in marine engineering. Due to the harsh ocean environment, marine structures are prone to adhesion and corrosion by marine biofouling. The biomimetic antifouling technology has been recognized as the most promising solution to marine biofouling, while there is still a long way to go to take this technology outside of research laboratories. In order to develop practical biomimetic antifouling techniques, this work presents a new water jet-based biomimetic antifouling model for marine structures to prevent the enrichment of biofouling. First, a semi-empirical formula is proposed based on the Schlichting self-similar solution to determine the effective width of the water jet. Then, a numerical simulation model is established to investigate the effects of the jet parameters (such as the jet aperture, jet velocity, and jet hole spacing) on the water jet distribution. Subsequently, visualization experiments are carried out to compare and validate the numerical simulation results. Finally, the simulation data are used to train a genetic neural network to predict the effective jet coverage ratio. The optimal parameters of the antifouling model are obtained corresponding to the largest effective jet coverage ratio. The findings of this study deliver a practical biomimetic antifouling technique for marine structures.
Domaine de référence : Antifouling
Auteur Incecik Atilla
Année de parution : 2020.
Type de document : Article de revue.
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Effect of phosphate availability on biofilm formation in cooling towers

Résumé : Phosphate limitation has been suggested as a preventive method against biofilms. P-limited feed water was studied as a preventive strategy against biofouling in cooling towers (CTs). Three pilot-scale open recirculating CTs were operated in parallel for five weeks. RO permeate was fed to the CTs (1) without supplementation (reference), (2) with supplementation by biodegradable carbon (P-limited) and (3) with supplementation of all nutrients (non-P-limited). The P-limited water contained ≤10 µg PO4 l−1. Investigating the CT-basins and coupons showed that P-limited water (1) did not prevent biofilm formation and (2) resulted in a higher volume of organic matter per unit of active biomass compared with the other CTs. Exposure to external conditions and cycle of concentration were likely factors that allowed a P concentration sufficient to cause extensive biofouling despite being the limiting compound. In conclusion, phosphate limitation in cooling water is not a suitable strategy for CT biofouling control.
Domaine de référence : Antifouling
Auteur Pinel Ingrid S. M., Kim Lan Hee, Borges Vitor R. Proença, Farhat Nadia M., Witkamp Geert-Jan, Loosdrecht Mark C. M. van, Vrouwenvelder Johannes S.
Année de parution : 2020.
Mots-clés : biofilm composition, Biofouling, microbial community analyses, nutrient limitations, principal component analysis, water quality.
Type de document : Article de revue.
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An Investigation into the application and practical use of (UV) ultraviolet light technology for marine antifouling

Résumé : This paper presents an alternative to conventional antifouling methods through the projection of ultraviolet (UV) irradiation onto submerged surfaces. Tests carried out establish that UV irradiation can effectively prevent biofouling growth on a small scale using commercially available technology with low cost. The demonstration for antifouling purposes also indicates the potential for ultraviolet irradiation to be applied to many different surfaces and diverse applications across the maritime industry. It is demonstrated that intermittent UV can achieve successful antifouling results on submerged surfaces. This significantly increases the design versatility for this antifouling approach, without the need for constant UV exposure there is inherently greater design flexibility for such applications. This suggests the possibility of in-situ UV antifouling systems which can be deployed when vessels are stationary. UV intensity measurements carried out suggest manufacturing variability exists between light emitting diodes (LEDs) of the same specification. The large variation in light intensity observed indicates that devices may perform below the indicated manufacturer's specifications and this could have a detrimental effect on antifouling performance. Results indicate that minor shadowing from direct UV irradiation exposure can impede antifouling performance. Tests indicate prolonged UV LED exposure is likely to result in the photo-degradation of polymer based materials.
Domaine de référence : Antifouling
Auteur Ryan Emmet, Turkmen Serkan, Benson Simon
Année de parution : 2020.
Type de document : Article de revue.
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Recent Progress of Biomimetic Antifouling Surfaces in Marine

Résumé : Marine biofouling is defined as the accumulation of living organisms on surfaces submerged in seawater. The growth of aquatic organisms on the man-made surfaces such as ships, buoys, sonar devices, and ocean infrastructures is regarded as a serious problem. Antifouling paints are developed to prevent the growth of biofouling by continually releasing biocides. In recent years, the outstanding antifouling performances discovered from natural creatures have motivated the development of new biomimetic antifouling approaches. In this progress report, the recent development of biomimetic antifouling surface is summarized. The main advantages and drawbacks of these systems are presented along with a brief introduction to their scientific basis. As the potential development of biomimetic coatings is still far from commercialization, some common yet hitherto neglected perspectives are discussed. It is believed that by selecting and combining the most effective antifouling mechanisms from nature, will bring a new era to nontoxic antifouling paints in the near future.
Domaine de référence : Antifouling
Auteur Yan Hao, Wu Qingshan, Yu Cunming, Zhao Tianyi, Liu Mingjie
Année de parution : 2020.
Mots-clés : antifouling, biocides, biomaterials, biomimetic, organisms, surface energy.
Type de document : Article de revue.
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Inhibition Effectiveness of Laser-cleaned Nanostructured Aluminum Alloys to Sulfate-reducing Bacteria Based on Super-wetting and Ultra-slippery Surfaces

Résumé : This paper is a continued study on laser cleaning removal of marine micro-biofoulings from Al alloy surfaces. According to our previous study, it is noted that the antifouling functions of the generated laser-cleaned metallic surfaces must be highlighted. In this work, the inhibition effectiveness of the laser-cleaned Al alloy surfaces was evaluated using a type of vital marine microorganism sulfate-reducing bacteria (SRB) Desulfovibrio desulfuricans subsp. desulfuricans in a dynamic bacterial solution. Before immersion tests, the laser-cleaned surfaces with nanostructures were chemically processed into superhydrophilic, superhydrophobic, and ultra-slippery surfaces. SRB attachment behaviors as well as inhibition mechanisms of the three surfaces to the SRB settlement were characterized and revealed. The SRB adhering to the above surfaces presented three different morphologies, i.e., broken, dented, and plump cells. Superhydrophilic surfaces unexpectedly showed a not inferior anti-bacterial ability. A piercing effect of nanostructures caused non-toxic mechanical damage of cell membranes. Anti-adhesion property of superhydrophobic solid-air hybrid surfaces was unreliable due to the loss of air-bubble. Morphology of the last surviving SRB cells left on the ultra-slippery surfaces was basically plump. Stable repellent function of the surfaces was responsible for the vigorous prevention of the adhesion of the SRB. Research results offer an instruction to the anti-bacterial/anti-adhesion property of the laser-cleaned surfaces, and a practical value for periodic service of marine high-end equipment.
Domaine de référence : Antifouling
Auteur Tian Ze, Lei Zhenglong, Chen Yanbin, Chen Chuan, Zhang Ruochen, Chen Xi, Bi Jiang, Sun Haoran
Année de parution : 2020.
Type de document : Article de revue.
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Superhydrophobic Coatings for Steel Pipeline Protection in Oil and Gas Industries : A Comprehensive Review

Résumé : Recently, there have been numerous deadly gas and oil pipeline explosions in the United States, resulting in extensive investigations based on corrosion and aged foundations. Superhydrophobic coatings are being developed using smart nano-based materials to act as protection layers on the surface of metallic parts against mechanical aggressors, corrosion, and fouling agents. These coatings have proven to be ideal candidates to protect steel pipelines, recently gaining much popularity. This review paper provides a comprehensive and critical assessment of the newly developed superhydrophobic coatings for steel pipelines, with a focus on their applications in the oil and gas industries. At first, the basic concept of wettability is introduced and the physical models governing the different kinds of wettability conditions are derived and explained. Then, various methods used to synthesize superhydrophobic coatings on steel substrates and recent findings from research work on different coating fabrication methods are discussed. Current applications of these developed superhydrophobic coatings for corrosion prevention, deicing, and anti-biofouling, among other treatments, within the last five years and their future trends are also extensively discussed. Based on the literature, of all the methods used for fabricating superhydrophobic coatings for steel pipelines, spraying is the most versatile and widely used. This method provides facile and economically viable mass fabrication of coatings on various steel substrates with desired microstructures. Silver nanoparticles (Ag NPs) are reported to be very resistant to microorganisms when used to fabricate superhydrophobic surfaces. Also, shape-memory polymers have recently been incorporated in the fabrication of superhydrophobic surfaces for self-healing functionality.
Domaine de référence : Antifouling
Auteur Ijaola Ahmed Olanrewaju, Farayibi Peter Kayode, Asmatulu Eylem
Année de parution : 2020.
Type de document : Article de revue.
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Biodegradable Polymeric Micro/Nano-Structures with Intrinsic Antifouling/Antimicrobial Properties : Relevance in Damaged Skin and Other Biomedical Applications

Résumé : Bacterial colonization of implanted biomedical devices is the main cause of healthcare-associated infections, estimated to be 8.8 million per year in Europe. Many infections originate from damaged skin, which lets microorganisms exploit injuries and surgical accesses as passageways to reach the implant site and inner organs. Therefore, an effective treatment of skin damage is highly desirable for the success of many biomaterial-related surgical procedures. Due to gained resistance to antibiotics, new antibacterial treatments are becoming vital to control nosocomial infections arising as surgical and post-surgical complications. Surface coatings can avoid biofouling and bacterial colonization thanks to biomaterial inherent properties (e.g., super hydrophobicity), specifically without using drugs, which may cause bacterial resistance. The focus of this review is to highlight the emerging role of degradable polymeric micro- and nano-structures that show intrinsic antifouling and antimicrobial properties, with a special outlook towards biomedical applications dealing with skin and skin damage. The intrinsic properties owned by the biomaterials encompass three main categories: (1) physical-mechanical, (2) chemical, and (3) electrostatic. Clinical relevance in ear prostheses and breast implants is reported. Collecting and discussing the updated outcomes in this field would help the development of better performing biomaterial-based antimicrobial strategies, which are useful to prevent infections.
Domaine de référence : Antifouling
Auteur Milazzo Mario, Gallone Giuseppe, Marcello Elena, Mariniello Maria Donatella, Bruschini Luca, Roy Ipsita, Danti Serena
Année de parution : 2020.
Mots-clés : antifouling, antimicrobial, antiviral, biomedical device, breast implant, chronic wound, ear prosthesis, electrospinning, skin.
Type de document : Article de revue.
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Chapter 13 - Nanobiocides against marine biofouling

Résumé : Biofouling is the unwanted accumulation of organisms on artificial submerged surfaces such as ship hulls, floating platforms, and power plant cooling ducts that have caused major economic and environmental impacts. Attempts to combat fouling organisms have had a long documented history. Currently, the application of nanotechnology in antifouling studies is prominent. In this chapter, we present a brief history of the prevention of undesirable fouling, identify the most commonly used nanomaterials as antifouling, list the advantages of using nanocoatings, exemplify some examples of commercialized nanocoatings, and finally suggest a model for the development of antifouling materials by describing the steps to be taken from selecting possible antifouling materials to regulating and legalizing the final product. Thus, this literature review provides a comprehensive view of biofouling and how nanotechnology is being used in antifouling studies.
Domaine de référence : Antifouling
Auteur Ferreira-Vançato Yollanda C. S., Dantas Fábio M. L., Fleury Beatriz G., Atta-ur-Rahman
Année de parution : 2021.
Mots-clés : Antifouling, Antifouling coatings, History of fouling prevention, Legislation, Natural and synthetic nanobiocides, Toxicity.
Type de document : Chapitre de livre.
Source : Elsevier
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PLL–Poly(HPMA) Bottlebrush-Based Antifouling Coatings : Three Grafting Routes

Résumé : In this work, we compare three routes to prepare antifouling coatings that consist of poly(l-lysine)–poly(N-(2-hydroxypropyl)methacrylamide) bottlebrushes. The poly(l-lysine) (PLL) backbone is self-assembled onto the surface by charged-based interactions between the lysine groups and the negatively charged silicon oxide surface, whereas the poly(N-(2-hydroxypropyl)methacrylamide) [poly(HPMA)] side chains, grown by reversible addition–fragmentation chain-transfer (RAFT) polymerization, provide antifouling properties to the surface. First, the PLL–poly(HPMA) coatings are synthesized in a bottom-up fashion through a grafting-from approach. In this route, the PLL is self-assembled onto a surface, after which a polymerization agent is immobilized, and finally HPMA is polymerized from the surface. In the second explored route, the PLL is modified in solution by a RAFT agent to create a macroinitiator. After self-assembly of this macroinitiator onto the surface, poly(HPMA) is polymerized from the surface by RAFT. In the third and last route, the whole PLL–poly(HPMA) bottlebrush is initially synthesized in solution. To this end, HPMA is polymerized from the macroinitiator in solution and the PLL–poly(HPMA) bottlebrush is then self-assembled onto the surface in just one step (grafting-to approach). Additionally, in this third route, we also design and synthesize a bottlebrush polymer with a PLL backbone and poly(HPMA) side chains, with the latter containing 5% carboxybetaine (CB) monomers that eventually allow for additional (bio)functionalization in solution or after surface immobilization. These three routes are evaluated in terms of ease of synthesis, scalability, ease of characterization, and a preliminary investigation of their antifouling performance. All three coating procedures result in coatings that show antifouling properties in single-protein antifouling tests. This method thus presents a new, simple, versatile, and highly scalable approach for the manufacturing of PLL-based bottlebrush coatings that can be synthesized partly or completely on the surface or in solution, depending on the desired production process and/or application.
Domaine de référence : Antifouling
Auteur Roeven Esther, Kuzmyn Andriy R., Scheres Luc, Baggerman Jacob, Smulders Maarten M. J., Zuilhof Han
Année de parution : 2020.
Type de document : Article de revue.
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Characterization of hazards and environmental risks of wastewater effluents from ship hull cleaning by hydroblasting

Résumé : Hydroblasting is used to remove biofouling and exhausted antifouling paints from ship hulls. Effluents generated from this process contain paint particles, metals, and booster biocides that may have toxic effects on organisms. To understand the potential risks of effluent discharge on marine environments, we analyzed the concentrations of metals in effluents collected during the dry-dock cleaning of ship hulls by hydroblasting. Copper and zinc were the principal metals, with concentrations ranging from 1440 to 9110 μg/L and 1800 to 22,600 μg/L, respectively. These concentrations are sufficiently high to cause harmful effects to most marine organisms. Model predictions suggested that the effluent discharge from hydroblasting posed risks to the wider marine environment of a hull-cleaning site, depending on the scale of the hull-cleaning operations and the size of the receiving environment, as well as various hydrodynamic factors. These effluents are inevitably hazardous, and their environmental release should be managed and regulated on the basis of site-specific risk assessments.
Domaine de référence : Antifouling
Auteur Soon Zhi Yang, Jung Jee-Hyun, Yoon Cheolho, Kang Jung-Hoon, Kim Moonkoo
Année de parution : 2021.
Mots-clés : Antifouling paint, Biofouling, Marine environment, Metal, Risk assessment.
Type de document : Article de revue.
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The effect of the loss of superhydrophobic surface properties on biofouling and flow around shipbuilding’s steel plates

Résumé : The dependence of the degree of biofouling on the magnitude of the contact angle θ during temporary degradation of the superhydrophobic coating of shipbuilding steel A40S in the process of being under water is examined. The experiment showed that the gas gap between the liquid and the structured surface makes it difficult for the first settlements to appear at θ ≥ 130°. In 35 days of being underwater and losing the hydrophobic properties of the coating, there were discovered the serpules (Serpula vermicularis), bryozoans (Bryozoa) and green algae (Chlorophyta), but there is no balanus (Balanidae - Chthamalus stellatus) and sponges (Porifera), which are observed on the untreated opposite sample side. The results of an in vivo experiment were used to CFD the dependence of water's flow velocity along the plate surface. Numerical calculation was determined the ratio of the initial flow velocity rate to its value at the end of the model plates. The transition from the hydrophilic state to the hydrophobic state reduces the value of the surface resistance by 1.44 times (changes in the velocity ν0/ν ≈ 2.6 are hydrophilic, ν0/ν ≈ 1.8 hydrophobic). An increase in surface roughness due to fouling will further increase the speed ratio by another 1.19–1.22 times.
Domaine de référence : Antifouling
Auteur Ivanovich Ukolov Aleksei, Nickolayevna Popova Tatiana, Viktorovich Kulish Andrey
Année de parution : 2020.
Mots-clés : CFD, Contact angle, Fouling, Roughness, Shipbuilding steel, Superhydrophobicity.
Type de document : Article de revue.
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Anti-Microbial Coating for the Prevention of Biofouling

Résumé : An anti-fouling coating comprising a polymeric compound, wherein a backbone of the polymeric compound is covalently bonded to a quorum sensing inhibitor, and wherein the anti-fouling coating has substantially no bactericidal activity, the quorum sensing inhibitor is substantially non-leaching from the anti-fouling coating, or both.
Domaine de référence : Antifouling
Auteur Hoffman Christopher M., Freeman Adam W., Gerasopoulos Kostantinos, Johnson James K., Sage Felix C., Langevin Spencer A., Messersmith Reid E., Eashoo Mark
Année de parution : 2020.
Type de document : Brevet.
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Method and System for Controlling Marine Growth Using Complex Ultrasonic Waveforms

Résumé : The method and system uses ultrasound (US) transducers in contact with an inboard surface underwater portions of marine vessels or structures. By first digitally generating disruptive, multi-frequency, interfering US waveform signals (complex waveforms, typically replicating a Bessel function) and then converting the signals into analog, the transducers generate disruptive, multi-frequency, interfering US waveforms through the underwater portions of the marine vessels and structures which waveforms disrupt unwanted marine growth on the water-side of the vessel or structure. The digital signals, and also the analog signals, are complex waveform signals, typically produced with a Bessel function. The US transducers are either circular membrane transducers or surface transducers. A computer processor coupled to a memory, generates the complex waveform signals fed to the US transducers.
Domaine de référence : Antifouling
Auteur Perdomo Isabela V., Barr Michael E.
Année de parution : 2020.
Type de document : Brevet.
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Characterization of silicon acrylic resin containing silica nanoparticles as candidate materials for antifouling and anticorrosion properties in seawater

Résumé : The damage caused by marine fouling organisms to ships and underwater artificial equipment is becoming increasingly serious issue, and the prevention and control of marine biofouling has always been a research hotspot in marine coatings. Aiming at the problems of poor adhesion, long curing time and high curing temperature of low-surface energy marine antifouling coatings of organosilicon, a hydrophobic low-surface energy nano-SiO2/silicon acrylic resin nanocomposite coating was synthesized. The anticorrosive property of the composite coatings was analyzed by simulated seawater periodic immersion experiments. The gel permeation chromatography analysis showed that polydimethyl-siloxanes (PDMS) is involved in cross-linking reactions. The dynamic thermomechanical analysis indicated that the glass transition temperature of resin is 58 °C. The contact angle (CA) test showed that the CA of nanocomposite coating is 109.99°. All the detection results can support the excellent antifouling and anticorrosion performance of the low surface energy nanocomposite coatings.
Domaine de référence : Antifouling
Auteur Jiang Weibin, Niu Quanliang, Cheng Lin, Zhou Tao, Xie Huasheng
Année de parution : 2020.
Type de document : Article de revue.
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Antifouling and anticorrosion performance of the composite coating made of tetrabromobisphenol-A epoxy and polyaniline nanowires

Résumé : Tetrabromobisphenol-A epoxy (TBEP), based on its hydrophobicity and antibacterial activity, is suitable to prepare top coating. Meanwhile, bisphenol-A epoxy (EP), based on its strong adhesion strength with metals, is a commonly material to prepare primer coating. Polyaniline (PANI) nanowires, which can facilitate the formation of passivation layer, is usually used as additive to reinforce the corrosion resistance of coatings. Herein, the composite coating composed of EP primer coating with 2 wt% PANI nanowires and TBEP top coating with 2 wt% PANI nanowires was assembled and characterized. Because the hydrophobic and antibiotic bromine atoms existed in TBEP, the composite coating exhibited low water absorption (0.32 wt%) and high antibacterial rate (over 93.17 %) compared with pure EP coating. Moreover, the composite coating had good adhesion with metals (dry: 5.65 MPa, wet: 4.07 MPa) and excellent anticorrosion properties (|Z|0.01 Hz > 1011 ohms·cm2 after 70 days immersion) in comparison to the composite coating without PANI nanowires, since the PANI nanowires provide multifunctional behaviors such as passivation, barrier, etc. This work might give a new perspective to prepare efficient antifouling and anticorrosion coating via reasonably combine the advantages of different functional materials.
Domaine de référence : Antifouling
Auteur Wu Changhao, Wang Jixiao, Song Shuangshuang, Wang Zhi, Zhao Song
Année de parution : 2020.
Mots-clés : Anticorrosion, Antifouling, Bisphenol-A epoxy, Composite coating, Polyaniline nanowires, Tetrabromobisphenol-A epoxy.
Type de document : Article de revue.
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Potential influence of microorganisms on the corrosion of carbon steel in the French high- and intermediate-level long-lived radioactive waste disposal context

Résumé : In the context of the high-level radioactive waste disposal CIGEO, the corrosion rate due to microbially influenced corrosion (MIC) has to be evaluated. In France, it is envisaged to dispose of high- and intermediate-level long-lived radioactive waste at a depth of 500 m in a deep geological disposal, drilled in the Callovo-Oxfordian claystone (Cox) formation. To do so, a carbon steel casing will be inserted inside disposal cells, which are horizontal tunnels drilled in the Cox. A specific cement grout will be injected between the carbon steel casing and the claystone. A study was conducted to evaluate the possibility of MIC on carbon steel in the foreseeable high radioactive waste disposal. The corrosiveness of various environments was investigated at 50°C and 80°C with or without microorganisms enriched from samples of Andra's underground research laboratory. The monitoring of corrosion during the experiments was ensured using gravimetric method and real-time corrosion monitoring using sensors based on the measurements of the electrical resistance. The corrosion data were completed with microbiological analyses including cultural and molecular characterizations.
Domaine de référence : Antifouling
Auteur Diler Erwan, Leblanc Vanessa, Gueuné Hervé, Larché Nicolas, Deydier Valerie, Linard Yannick, Crusset Didier, Thierry Dominique
Année de parution : 2020.
Mots-clés : carbon steel, CIGEO, electrical resistance sensor, microbially influenced corrosion, radioactive waste.
Type de document : Article de revue.
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Distinct Temporal Succession of Bacterial Communities in Early Marine Biofilms in a Portuguese Atlantic Port

Résumé : Marine biofilms are known to influence the corrosion of metal surfaces in the marine environment. Despite some recent research, the succession of bacterial communities colonizing artificial surfaces remains uncharacterized in some temporal settings. More specifically, it is not fully known if bacterial colonizers of artificial surfaces are similar or distinct in the different seasons of the year. In particular the study of early biofilms, in which the bacterial cells communities first adhere to artificial surfaces, are crucial for the development of the subsequent biofilm communities. In this work, we used amplicon-based NGS (next-generation sequencing) and universal 16S rRNA bacterial primers to characterize the early biofilm bacterial communities growing on 316L stainless steel surfaces in a Northern Portugal port. Sampling spanned 30-day periods in two distinct seasons (spring and winter). Biofilm communities growing in steel surfaces covered with an anti-corrosion paint and planktonic communities from the same location were also characterized. Our results demonstrated that distinct temporal patterns were observed in the sampled seasons. Specifically, a significantly higher abundance of Gammaproteobacteria and Mollicutes was found on the first days of biofilm growth in spring (day 1 to day 4) and a higher abundance of Alphaproteobacteria during the same days of biofilm growth in winter. In the last sampled day (day 30), the spring biofilms significantly shifted towards a dominance of photoautotrophic groups (mostly diatoms) and were also colonized by some macrofouling communities, something not observed during the winter sampling. Our results revealed that bacterial composition in the biofilms was particularly affected by the sampled day of the specific season, more so than the overall effect of the season or overall sampling day of both seasons. Additionally, the application of a non-fouling-release anti-corrosion paint in the steel plates resulted in a significantly lower diversity compared with plates without paint, but this was only observed during spring. We suggest that temporal succession of marine biofilm communities should be taken in consideration for future antifouling/anti-biofilm applications.
Domaine de référence : Antifouling
Auteur Antunes Jorge T., Sousa António G. G., Azevedo Joana, Rego Adriana, Leão Pedro N., Vasconcelos Vitor
Année de parution : 2020.
Mots-clés : Marine biofilms, Marine corrosion, Marine fouling, pioneer bacteria, Steel surfaces, Temporal succession.
Type de document : Article de revue.
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Recent Progress of Biomimetic Antifouling Surfaces in Marine

Résumé : Marine biofouling is defined as the accumulation of living organisms on surfaces submerged in seawater. The growth of aquatic organisms on the man-made surfaces such as ships, buoys, sonar devices, and ocean infrastructures is regarded as a serious problem. Antifouling paints are developed to prevent the growth of biofouling by continually releasing biocides. In recent years, the outstanding antifouling performances discovered from natural creatures have motivated the development of new biomimetic antifouling approaches. In this progress report, the recent development of biomimetic antifouling surface is summarized. The main advantages and drawbacks of these systems are presented along with a brief introduction to their scientific basis. As the potential development of biomimetic coatings is still far from commercialization, some common yet hitherto neglected perspectives are discussed. It is believed that by selecting and combining the most effective antifouling mechanisms from nature, will bring a new era to nontoxic antifouling paints in the near future.
Domaine de référence : Antifouling
Auteur Yan Hao, Wu Qingshan, Yu Cunming, Zhao Tianyi, Liu Mingjie
Année de parution : 2020.
Mots-clés : antifouling, biocides, biomaterials, biomimetic, organisms, surface energy.
Type de document : Article de revue.
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Full Text PDF

Domaine de référence : Antifouling
Année de parution : 0.
Type de document : Pièce jointe.
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Research Strategies to Develop Environmentally Friendly Marine Antifouling Coatings

Résumé : There are a large number of fouling organisms in the ocean, which easily attach to the surface of ships, oil platforms and breeding facilities, corrode the surface of equipment, accelerate the aging of equipment, affect the stability and safety of marine facilities and cause serious economic losses. Antifouling coating is an effective method to prevent marine biological fouling. Traditional organic tin and copper oxide coatings are toxic and will contaminate seawater and destroy marine ecology and have been banned or restricted. Environmentally friendly antifouling coatings have become a research hotspot. Among them, the use of natural biological products with antifouling activity as antifouling agents is an important research direction. In addition, some fouling release coatings without antifoulants, biomimetic coatings, photocatalytic coatings and other novel antifouling coatings have also developed rapidly. On the basis of revealing the mechanism of marine biofouling, this paper reviews the latest research strategies to develop environmentally friendly marine antifouling coatings. The composition, antifouling characteristics, antifouling mechanism and effects of various coatings were analyzed emphatically. Finally, the development prospects and future development directions of marine antifouling coatings are forecasted.
Domaine de référence : Antifouling
Auteur Gu Yunqing, Yu Lingzhi, Mou Jiegang, Wu Denghao, Xu Maosen, Zhou Peijian, Ren Yun
Année de parution : 2020.
Mots-clés : antifoulant, antifouling coating, antifouling mechanism, environmentally friendly, polymer.
Type de document : Article de revue.
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Biologically Fabricated Nanomaterials for Mitigation of Biofouling in Oil and Gas Industries

Résumé : Oil and gas industries suffer from a severe problem represented in biofouling. Biofouling occurs due to the colonization of micro-and macro-organisms on the surface of metallic structures. Biofouling has catastrophic economical, financial, environmental and health implications. It results in loss/contamination of products, high energy and fuel consumption, air pollution, etc. Hence, anti-biofouling strategies have been extensively investigated in the last few years. These strategies include the usage of biocides and protective paints and coatings. However, the worldwide new trend is to employ nanobiotechnology to eradicate biofouling negative impacts. Nanobiotechnology is a science in which different scientific fields are combined altogether including; nanotechnology, biotechnology, materials science, physics, chemistry and biology. Although, physical and chemical synthesis approaches produce nanoparticles with definite size and shape, nevertheless, these synthetic methodologies have some disadvantages such as complication, high costs, production of hazardous byproducts which are lethal to the environment as well as human health. Moreover, physical and chemical synthesis methods require the presence of external chemical reducing and capping agents. Biological synthesis of nanoparticles depends on using biological entities such as bacteria, fungi, actinomycetes, algae, agro-industrial wastes and plant extracts. This chapter summarizes the different biological entities that can be used as nano-bio-factories. It also emphasizes the-state-of the-art of the possible use of biogenic nanomaterials as effective biocides to mitigate biofouling.
Domaine de référence : Antifouling
Auteur Omran Basma A., Abdel-Salam Mohamed Omar, Omran Basma A., Abdel-Salam Mohamed Omar
Année de parution : 2020.
Mots-clés : Biofouling mitigation, Biological synthesis, Nano-bio-factories, Nanobiotechnology, Nanoparticles.
Type de document : Chapitre de livre.
Source : Springer International Publishing
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The occurrence of modern organic antifouling biocides in Danish marinas

Résumé : Antifouling biocides are known to leach out of paints and into the aquatic environment. There is currently a data gap on the occurrence of the current antifouling biocides, as legislative changes caused a change in the antifouling market. Therefore, a comprehensive monitoring study was performed across 13 Danish marinas, both waters and sediments were analyzed, including a transect and a study with seasonal resolution. Three biocides, i.e., Medetomidine, Tralopyril, and DCOIT were not detected in any of the samples. More commonly found, in 11 of the 13 marinas, were the hydrolysis products of Dichlofluanid (DMSA) and Tolylfluanid (DMST). These biocides rapidly dropped in concentration and reached background levels around 200 m from the source. The antifouling biocide Irgarol 1051 was found in all sediment samples and half of all water samples. The concentrations of Irgarol were lower than previously monitored. The decrease can likely be attributed to legislative changes and its disapproval for use since 2016.
Domaine de référence : Antifouling
Auteur Koning Jasper T., Bollmann Ulla E., Bester Kai
Année de parution : 2020.
Mots-clés : Dichlofluanid & DMSA, Irgarol, Marine environment, Monitoring, Tolylfluanid & DMST.
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.