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Numerical modelling of three-dimensional wave-current interactions in complex environment : Application to Alderney Race

Résumé : Modelling three-dimensional wave-current-turbulence interactions in extreme tidal environments is still challenging and necessary for the development of the tidal industry, particularly for the dimensioning of tidal converters. Following this objective, we focus our study on the most energetic tidal site in Western Europe, the Alderney Race (France). Due to the strong tidal current at this location, wave-current interactions were poorly studied by the past and often neglected. We propose to assess how they impact the Alderney Race hydrodynamic by the use of numerical modelling and in-situ measurements. In this study, the following wave-current interactions were observed: (i) Stokes drift effects inducing an increase/decrease in the current depending on the angle between waves and current, with a maximum influence near the surface, (ii) wave enhancement of the bottom friction reducing the tidal current, (iii) refraction of waves by the current, generating changes in waves directions, and (iv) wave breaking ascribed to tidal current, increasing the turbulent mixing. A non-stationary time delay, varying within a same tidal cycle, was noted, which is reduced by including the local wind effects and by adjusting the bottom stress formulation. This study shows that wave-current interactions play a non-negligible role in Alderney Race although the strong tidal current and that they need to consider by the tidal industry.
Domaine de référence : EMR
Auteur Bennis Anne-Claire, Furgerot Lucille, Bailly Du Bois Pascal, Dumas Franck, Odaka Tina, Lathuilière Cyril, Filipot Jean-François
Année de parution : 2020.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Wave power extraction from a tubular structure integrated oscillating water column

Résumé : Integrating wave energy converters with marine structures such as breakwaters, piles, and offshore wind turbines offers benefits in terms of wave power extraction, construction costs, and survivability. In this paper, the integration of an oscillating water column(OWC) into a vertical tubular structure is considered. The OWC chamber is enclosed by the tubular-structure with its submerged side partially open to the sea. As ocean waves propagate through the device, an air turbine installed at the top of the chamber can be driven to extract wave power. An analytical model based on potential flow theory and the eigen-function matching method is developed to solve the wave scattering and radiation problems of the device in finite water depths. Wave excitation volume flux, hydrodynamic coefficients, optimal turbine damping and power capture factor are evaluated. Upon successful validation, the model is applied to investigate the effect of the radius and finite wall thickness of the tubular-structure, the size and position of the opening on wave power extraction. We find that a thinner chamber wall thickness offers benefits to wave power extraction in terms of a broader primary band of power capture factor response, and that a broader and higher capture factor band can be achieved by increasing the height of the vertical opening.
Domaine de référence : EMR
Auteur Zheng Siming, Zhu Guixun, Simmonds David, Greaves Deborah, Iglesias Gregorio
Année de parution : 2020.
Mots-clés : Analytical model, Hydrodynamics, Oscillating water column, Potential flow, Tubular structure, Wave power.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Aerodynamic and Hydrodynamic Study of Offshore Wind Turbine Foundation

Résumé : Wind is an excellent source of renewable energy As the requirement of energy is increasing day by day thenon-renewable energy sources get deficient in fulfillingthe requirement, offshore windmills are the need to be focused towards the sustainable development. This study focuses on investigating the fixed jacket type offshore structure considering environmental loadings such as aerodynamic loading considered in all direction and hydrodynamic loading causes due to wave which act as an extreme effect on structure in also considering seismic loading for analysis and design offshore wind turbine structure situated at a water depth of 16 m. Both structures were analyzed for deformation, stress in member and forces generated at the base of the structure result shows that 14m footprint jacket is well efficient to take comparatively more axial compression load.
Domaine de référence : EMR
Auteur Kambekar A. R., Giri Shubham R.
Année de parution : 2020.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

New technology demonstration project for a floating offshore wind turbine foundation with guy wire supported tower

Résumé : A floating offshore wind turbine (FOWT) concept with a guy wire supported tower was investigated to obtain results on its elastic response characteristics in waves. The joint research project, of which the Ocean Space Planning Laboratory of the University of Tokyo is a project partner, is initiated by the New Energy and Industrial Technology Development Organization (NEDO). The concept aim is to lower the cost of FOWTs by using a lightweight structure tensioned with guy wires and a downwind turbine concept. Thereby, the whole floater is a weatervane system, adjusting itself into the wind direction around a single point turret mooring.
Domaine de référence : EMR
Auteur Schnepf Anja
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Schnepf - New technology demonstration project for a floating.pdf

Domaine de référence : EMR
Année de parution : 0.
Type de document : Pièce jointe.
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The Water Power Technologies Office and Powering the Blue Economy

Domaine de référence : EMR
Auteur McShane Bill
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Structural Design and Analysis of a 5MW Offshore Wind Turbine Blades Under Critical Aerodynamic Loads

Résumé : The rise in fuel prices and the depletion of fossil resources; due to the demand created by rapid industrial growth; have pushed states to resort to renewable energies, notably Offshore wind turbine (OWT). Our study aims to propose a structural design for the development of a composite blade of 48m length for an offshore wind turbine. The design loads were determined from various loading cases indicated in the international specifications for the wind energy conversion system. Parametric studies are performed with the ABAQUS finite element analysis software to determine and propose a particular structure configuration, which can effectively withstand extreme load conditions.
Domaine de référence : EMR
Auteur Boudounit H, Tarfaoui M, Saifaoui D
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Editorial : Advanced research on offshore structures and foundation design : part 1

Domaine de référence : EMR
Auteur Fazeres-Ferradosa T., Rosa-Santos P., Taveira-Pinto F., Vanem E., Carvalho H., Correia J.
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Impact of tidal turbine biofouling on turbulence and power generation

Résumé : This work is a part of a project aiming to study the impact of biofouling on turbine performances. It describes the fluid-structure calculation applied to a Darrieus turbine using the Openfoam code in order to take the mass variation of the solid into account. Forced and induced rotation simulations are compared for water and air. For both fluids, the results show that the flow field in the rotor’s wake is similar for the two types of movement. Therefore the solid solver does not change fluid results. Blue mussels are fixed to the blades, which leads to a supplementary mass that has been decorrelated from hydrodynamics to understand its effects. For the chosen implantation (small), the only observable modification is a delay between light and heavier rotors. However, the coarse mesh used in this study is not sufficient to compute the flow around blades with accuracy. This has a strong impact on calculation of forces and by extension on the rotor’s dynamics. A mesh convergence procedure is planned to reach the necessary mesh precision and laboratory experiments should be made in order to validate dynamical results with low flow speed.
Domaine de référence : EMR
Auteur Robin Ilan, Bennis Anne-Claire, Dauvin Jean-Claude, Gualous Hamid
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Floating device supporting an offshore wind turbine, and corresponding floating wind turbine unit

Résumé : A floating device for supporting an offshore wind turbine, comprising a central floating pillar for fixedly receiving a tower of the wind turbine, at least three peripheral floaters, and one leg per floater, each leg extending in a longitudinal direction that runs radially in relation to the central pillar; each leg has a proximal end that is secured to the central pillar, and a distal end that is secured to the floater; the legs include an outer tubular element, which extends in the longitudinal direction of the leg and has a curved cross-section perpendicularly to the longitudinal direction, and an inner tubular element, which extends in the longitudinal direction of the leg and has a polygonal cross-section perpendicularly to the longitudinal direction, the polygonal cross-section being inscribed in the curved cross-section. The invention also relates to a floating wind turbine unit comprising the device and a wind turbine.
Domaine de référence : EMR
Auteur Gatescoupe Julien, Heisel Pascal, Marin Yves
Année de parution : 2019.
Mots-clés : floating, floating device, leg, legs, wind turbine.
Type de document : Brevet.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Tidal power systems : A review

Domaine de référence : EMR
Auteur Elyazid Amirouche, Kaci Ghedamsi, Djamal Aouzellag
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Design Method of Jacket Foundation for Tidal Current Turbine

Résumé : Nowadays, it is a main utilizing mode to generate electric power using tidal current energy, which has been getting rapid development worldwide. Jacket foundation, as a main foundation type, plays an important role to ensure the safety of the tidal current turbine. Thus, a design method of jacket foundation for tidal current turbine is a research focus. In the paper, The SACS-Tidal-bladed joint design method combined SACS, a design tool for offshore engineering, with Tidal-bladed, a load analysis tool for tidal current turbine, is put forward. The method mainly consists of three key design cases, namely mode analysis, ultimate limit analysis and fatigue analysis. Moreover, the jacket foundation for a 2300kW tidal current turbine is designed using the method. Because the results are satisfied to the relevant specifications, the running safety of the 2300kW tidal current turbine with the jacket foundation can be ensured.
Domaine de référence : EMR
Auteur Jia Fayong, Chu Jingchun, Yuan Ling, Pan Lei, Wang Ting
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Uncertainty assessment for the extreme hydrodynamic responses of a wind turbine semi-submersible platform using different environmental contour approaches

Résumé : This paper aims to assess the uncertainty on the extreme responses of a semi-submersible wind turbine using two environmental contour approaches. The approaches are based on the inverse First Order Reliability Method and the direct Monte Carlo Simulation with different sample sizes. The long-term sea states are described by a 3-parameters Weibull distribution for the significant wave height and a conditional log-normal distribution for the zero-up crossing period. Two extreme sea states are extracted from each environmental contour, which are associated with the maximum significant wave height and maximum zero-upcrossing period. A 3-h time domain simulation for each sea state is conducted by adopting a validated numerical model. The root mean square for all the response spectra are estimated and compared to each other. It is observed that despite the small deviation between the significant wave heights resulting from adopting different environmental contour approaches, the deviation between the resulting responses is much more significant. The Gumbel and the generalized extreme value distributions are fitted to the maximum extreme response values for each sea state and unified fitted parameter are obtained.
Domaine de référence : EMR
Auteur Raed K., Teixeira A. P., Guedes Soares C.
Année de parution : 2019.
Mots-clés : Environmental contour, Extreme response, Semi-submersible, Uncertainty, Wind turbine.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Performance evaluation of a submerged tidal energy device with a single mooring line

Résumé : A submerged tidal energy device with contra-rotating Diffuser Augmented Tidal Turbines (DATTs) has been investigated in this paper. The device is moored to the seabed with a single mooring line, which limit it to operate at mean water depth, but otherwise allows it to float freely with the tidal current, like a kite in the wind, to harness tidal current energy. This research focuses on the evaluation of stability and power generation of the submerged tidal energy device based on 1:5th scaled model tests and the full-scaled prototype sea trials. A 1:5th scaled model had been manufactured and tested in a circulating water channel to observe the power generation performance and working attitude around the designed inflow velocity. A full-scaled prototype was manufactured and tested near the CHU Island in Shandong Province, China. The results show that the device can change its direction automatically to make the DATTs face the tidal inflow, as the tidal current changes direction. The device has a good stability in pitch and roll motions. But the device's stability in yaw motions is worse than the other two, which will significantly affect the power generation performance and introduce more demanding structural requirements.
Domaine de référence : EMR
Auteur Guo Bin, Wang Dazheng, Zhou Junwei, Shi Weichao, Zhou Xu
Année de parution : 2019.
Mots-clés : Contra-rotating, Diffuser-augmented tidal turbine (DATT), Full-scaled prototype, Model tests, Single mooring line, Submerged tidal energy device, Tidal current turbine.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

PMSG-based Tidal Current Turbine Biofouling Diagnosis using Stator Current Bispectrum Analysis

Résumé : Most of signals in the electrical machines and drives are non-Gaussian and highly nonlinear in nature. A useful set of techniques for examining these kinds of signals relies on the spectral representations of higher-order statistics (HOS), well-known as polyspectra. They describe statistical dependences of frequency components that are neglected by traditional spectral measures. The bispectrum is the most used HOS, and studying higher-order correlations provides more information about the electromechanical system's behavior. It helps in building more accurate diagnostic models. Based on this proper relationship the overall aim of the current work is the interpretation of the stator current tidal turbine bispectrum under imbalanced rotor blades condition. Based on this proper relationship, the overall aim of the current work is the interpretation of the permanent magnet synchronous generator (PMSG)-based tidal current turbine (TCT) stator current bispectrum for the diagnosis of biofouling. The proposed bispectrum-based diagnosis method has been tested using experimental data issued from a TCT experiencing biofouling emulated by an attachment on the turbine rotor. The achieved results clearly indicate the feasibility and efficacy of the proposed method.
Domaine de référence : EMR
Auteur Saidi Lotfi, Benbouzid Mohamed, Diallo Demba, Amirat Yassine, Elbouchikhi Elhoussin, Wang Tianzhen
Année de parution : 2019.
Mots-clés : biofouling, Bispectrum, Blades, Frequency measurement, Generators, Rotors, spectral kurtosis, stator current, Stators, tidal turbine, turbulence, wave, Wind turbines.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

The effects of wind turbine wakes on the fatigue lives of the downwind turbines’ support structures

Résumé : This study evaluated, by time-domain simulations, the fatigue lives of several jacket support structures for 4MW wind turbines distributed throughout an offshore wind farm off Taiwan’s west coast. An in-house RANS-based wind farm analysis tool, WiFa3D, has been developed to determine the effects of the wind turbine wake behaviour on the flow fields through wind farm clusters. To reduce computational cost, WiFa3D employs an actuator disk model to simulate the body forces imposed on the flow field by the target wind turbines. WiFa3D simulations were performed for a range of environmental conditions, which were then combined with preliminary site survey metocean data to produce a long-term statistical environment. The short-term wind loads on the wind turbine rotors were calculated by an unsteady blade element momentum (BEM) model of the target 4MW wind turbines. The fatigue assessment of the jacket support structure was then conducted by applying the Rainflow Counting scheme on the hot spot stresses variations, as read-out from Finite Element results, and by employing appropriate SN curves. The fatigue lives of the jacket support structures at various locations in the wind farm showed significant variations with the preliminary design condition that assumed a single wind turbine without wake disturbance from other units.
Domaine de référence : EMR
Auteur Nelson Bryan, Xie Meng-Jie, Hou Jian-Lun, Lin Tsung-Yueh, Section D
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Composite Ducted Tidal Turbine Design : Modelling strategy

Résumé : A propeller in-house panel method code coupled with the blade element momentum theory (BEM) was used to design a bare tidal turbine which reaches 88% of the Betz limit. The addition of a duct at the same overall cross section area has been investigated. The numerical results show that the ducted turbine’s power coefficient, which was computed using the overall cross section area, can be slightly increased if a camber duct profile with a flare angle is used. The hydrodynamic pressure obtained with the panel method code was then implemented as boundary conditions into the FE model in order to compute the static mechanical behavior of the composite duct. However several iterations of material distribution have been performed to satisfy two main criteria which are the damage initiation according to Hashin criteria and the maximum deflexion at the exit of the duct. This approach leads to introduce the ducted configuration presenting the best ration ‹‹power/mass». Furthermore, to understand the dynamic behaviour and the effects of the low velocity impact damage on the duct structural constraints, a 3D damage model involving inter/intralaminar mechanisms combination has been developed. The proposed damage model has been validated through low velocity impact experimental measurement carried out on glass/epoxy samples. A submodeling procedure has been used to reduce significantly the computational time of the certification procedure involving a marine propeller hydrodynamic model combined to 3D composite damage model.
Domaine de référence : EMR
Auteur Mohammed Mahrez Ait, Laurens Jean Marc, Benyahiya Hamza
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

On the experimental study of a concentric wave energy array adapted to an offshore floating platform

Résumé : Experimental results of the dynamics of a small scale concentric wave energy converter array adapted to a floating offshore platform are presented. A small scale prototype is tested without and with twelve conical heaving point absorbers. The free decay and regular wave tests are carried out in an ocean basin to understand the hydrodynamic interactions between various elements of the floating offshore platform and wave energy converter array. Meanwhile, the heave motions of the buoys are observed in regular waves with and without dampers for the initial estimation of power take-off damping as a pitch control module. The results show the improvements in heave, pitch, and roll performance of the platform due to the interactio n between the buoys and platform.
Domaine de référence : EMR
Auteur Kamarlouei Mojtaba, Gaspar Jose F, Calvário Miguel, Hallak Thiago S, Soares Carlos G
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Mooring system fatigue analysis of a floating offshore wind turbine

Résumé : Mooring systems are under a cyclic loading process caused by the randomness of metocean conditions, which could lead to a fatigue failure of the station keeping system. The present paper presents an innovative methodology for the assessment of floating offshore wind turbine mooring system fatigue considering the full lifetime of the structure. The method integrates the impact of the life cycle metocean conditions over the dynamic performance of the platform thanks to coupled numerical models, selection and non-linear data interpolation techniques and commonly accepted fatigue approaches. One of the benefits of using this methodology is that there are no uncertainties due to the selection of a reduced set of sea states. The methodology is applied to a set of moorings with different properties in the DeepCwind platform to evaluate the solution which offers the best compromise between size and fatigue damage. Results show that the best long-term mooring behaviour is achieved with a weight of approximately 300 kg/m. A comparison is conducted between the fatigue damage obtained through the life-cycle method and conventional methods. The mean differences observed between the standard and the new method proposed are between 13% and 49% depending on the use of the S–N or T-N curves.
Domaine de référence : EMR
Auteur Barrera Carlos, Battistella Tommaso, Guanche Raúl, Losada Iñigo J.
Année de parution : 2019.
Mots-clés : Fatigue, Floating offshore wind turbine, Mooring system, Non-linear interpolation techniques.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Wake field study of tidal turbines under realistic flow conditions

Résumé : Numerical modelling of the flow interactions between tidal turbines in arrays is a prerequisite to assess the energy production potential and to optimise the layout of tidal stream energy farms. It requires (i) a refined representation of the tide propagation and (ii) a reliable estimate of the flow characteristics around the turbines. The Actuator Disk (AD) theory is recognised as a reliable parameterisation to approach the far wake of fixed horizontal-axis turbines and was therefore implemented to provide recommendations as regards to the design of arrays, especially the optimal spacing between devices. However, analysis of the arrangement of tidal stream turbines are typically restricted to schematic test cases with idealised bathymetry and inflow conditions. The present study aims to investigate the flow interactions between turbines in a stream energy site with spatially- and time-varying tidal conditions. The site of application is the Alderney Race (English Channel), an area with strong potential for the exploitation of tidal energy in European shelf seas. The three-dimensional numerical model Telemac3D is used to capture the flow at both the regional and the array scales. Predictions are first assessed against ADCP measurements acquired around the island of Alderney. A series of simulations, representing turbines with the AD theory, are then performed to investigate the influence of the wake interactions on the energy production of individual devices. In those simulations, the turbines are represented with the AD theory. The zone occupied by the turbines is 20D-long and 15D-wide (D is the turbine diameter). Different layouts (isolated, aligned and staggered turbines) and different longitudinal and lateral spacings are considered to investigate the effect of the turbines’ arrangement and density on the array energy production. The results show that, for a given turbines density within the array, the staggered layout produces more than the aligned layout (+16%). When the turbines are staggered, a minimal lateral spacing of 5D is required to avoid wake overlapping. However, when the turbines are aligned, the lateral spacing has a small influence on the turbines production. It is therefore possible to pack the turbines close to each other in the lateral direction. The simulations also outline that the turbulence develops much faster within the array when the turbines are aligned.
Domaine de référence : EMR
Auteur Thiébot Jérôme, Guillou Nicolas, Guillou Sylvain, Good Andrew, Lewis Michael
Année de parution : 2019.
Mots-clés : Actuator disk theory, Alderney race, Numerical modelling, Telemac, Tidal turbine.
Type de document : Article de revue.
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A comprehensive assessment of turbulence at a tidal-stream energy site influenced by wind-generated ocean waves

Résumé : Velocity measurements collected by an upward-looking acoustic Doppler current profiler were used to provide the first study of ambient turbulence in Alderney Race. Turbulence metrics were estimated at mid-depth during peak flooding and ebbing tidal conditions. The dissipation rate ε and the integral lengthscale (L) were estimated using two independent methods: the spectral method and the structure function method. The spectral method provided ε and (L) estimates with standard deviations twice lower than that obtained from the structure function method. Removal of wave and Doppler noise-induced bias when estimating the dissipation rate was shown to be a crucial step in turbulence characterization. It allowed for a significant refining in (L) estimates derived from the spectral and structure function methods of 35% and 20% respectively. The integral lengthscale was found to be 2–3 times the local water depth. It is considered that these findings could be valuable for current turbine designers, helping them optimizing their designs as well as improving loading prediction through the lifetime of the machines.
Domaine de référence : EMR
Auteur Thiébaut Maxime, Filipot Jean-François, Maisondieu Christophe, Damblans Guillaume, Duarte Rui, Droniou Eloi, Chaplain Nicolas, Guillou Sylvain
Année de parution : 2019.
Mots-clés : ADCP, Alderney race, Doppler noise, Tidal energy, Turbulence, Wave.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Improvement of aerodynamic performance of an offshore wind turbine blade by moving surface mechanism

Résumé : In the present study, the effects of a moving surface on the aerodynamic characteristics of an offshore wind turbine blade were numerically examined. The S809 airfoil was considered as the blade section. A part of the airfoil surface was replaced with a moving surface as a flow control mechanism. To achieve the highest mechanical performance of the airfoil at each angle of attack, the effects of location and speed of the moving surface on the flow characteristics were studied. The flow simulation was carried out using a computational fluid dynamics technique. The results of this study indicated that the use of a moving surface with appropriate speed and location could enhance the airfoil performance. As the angle of attack increased, a stronger moving surface was needed. The performance improvement for α = 8°, 11°, 14°, and 17° was 30%, 62%, 131%, and 152%, respectively. In addition, the performance of a three-bladed horizontal axis wind turbine was numerically analyzed in the range of tip speed ratio, 4 ≤ TSR ≤ 9. It was observed that the moving surface significantly improved the torque and power generated by the turbine, especially at low TSRs. This improvement was over 90% for TSR < 5.
Domaine de référence : EMR
Auteur Salimipour Erfan, Yazdani Shima
Année de parution : 2020.
Mots-clés : Blade element momentum method, Computational fluid dynamics, Mechanical performance, Moving surface, Offshore wind turbine blade, Offshore wind turbine power.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

An Optimal Power Flow Approach Including Wind and Tidal Generation

Résumé : Electrical systems with high penetration of renewable energies are increasingly common. Among these sources, wind energy is the one that has most propagated with the technology in great development and the fact that much of the world population density is located in the coastal where there is strong incidence of winds, favoring the installation of large parks that will not need of long transmission lines for delivery this energy. Power through tidal current streams is a promising source as it presents as one of the advantages the high predictability of energy resources. Power systems analysis tools need to include these technologies as they are a worldwide trend. This paper aims to present a probabilistic modeling to include these sources in the optimal power flow problem. For this, wind farms, tidal currents and hybrids ones were modeled. They were included in the network as a form of power injection to analyze the operational system costs. The methodology was applied in the WSCC test system and had shown that the costs are significantly reduced, and that complementarity among the sources is an important factor for the constancy of the output power of the source.
Domaine de référence : EMR
Auteur Fernandes Italo G., Pereira Felipe B., Gomes Thiago L., Sá Bruno F.
Année de parution : 2019.
Mots-clés : Generation, Optimal Power Flow, Renewable, Tidal, Wind.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

A New Control Algorithm for Directly Interconnected Offshore Wind Turbine Generators

Résumé : A new control algorithm for Directly Interconnected offshore Wind Turbines with permanent magnet synchronous Generators (DIWTG) is presented. In the DΓWTG offshore wind park configuration, Wind Turbines with Permanent Magnet Synchronous Generators (WTPMSG) are directly connected to the offshore AC collection grid without using a power converter. The offshore AC collection grid is then connected, via a transformer, to the offshore AC transmission grid. In order to achieve maximum power point tracking, the (collective) speed of DΓWTGs is controlled by an onshore back to back converter. By measuring the active power and speed of the permanent magnet generators, wind speed at each turbine is estimated and used for calculation of the reference speed of WTPMSGs. Voltage control at the power converter side is performed in a way which allow the DΓWTGs to be operated at a constant V/f where the maximum resultant frequency at nominal wind speed is 16.67 Hz.
Domaine de référence : EMR
Auteur Omerdic Emir, Osmic Jakub, Toal Daniel, O’Donnell Cathal W.
Année de parution : 2019.
Mots-clés : Control, Control systems, directly interconnected, offshore, Optimized production technology, PMSG, Underwater cables, Voltage control, Wind power generation, Wind speed, wind turbine, Wind turbines.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

iWindCr wireless sensor system for corrosion detection and monitoring of offshore wind turbine structures

Domaine de référence : EMR
Auteur Simandjuntak Sarinova, Bausch Nils, Farrar Andrew Stephen, Thomas Bob, Nash Adrian, Muna Joseph, Jonsson Carl, Mathew Diana, Ahuir-Torres Juan
Année de parution : 2019.
Type de document : Article de colloque.
Source : Institute of Marine Engineering, Science and Technology (IMarEST)
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ESwift : Smart and Self-Stabilizing Water-Wind Floating Turbine

Résumé : In April 2019, a team of Keio University and Bucknell University students was assembled to participate in Ericsson Innovation Awards with a novel concept for generating renewable energy. This conceptual system consists of a vertical axis wind turbine, a crossflow marine hydrokinetic turbine, a floating platform integrated with a quadcopter system, and three to four temporary mooring lines with ship-type anchors. The proposed designed aims to offer solutions to two current problems of floating offshore wind energy: high construction cost of floating platforms and difficulties in maintenance of mooring lines. The combination of two vertical-axis turbines into a single floating platform would enable the system, namely ESwift, to extract energy from both wind and current resources. Additionally, due to the utilization of vertical axis turbines, the center of gravity of the proposed concept is significantly lower with respect to water level, compared to that of existing floating horizontal axis wind turbines, which would potentially reduce the floater's size and construction cost. Lastly, the integrated quadcopter mechanism would assist the floater in terms of stability and mobility, and enables an array of ESwifts to automatically rearrange for maximal energy generation. The authors hope that readers would find the idea described in this open access letter worth pursuing and would further develop and commercialize the ESwift concept.
Domaine de référence : EMR
Auteur Doan Minh N., Badri Mehdi, Tran Trung B., Kai Yuriko
Année de parution : 2019.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

STRUCTURAL CONTROL OF OFFSHORE WIND TURBINES USING PASSIVE AND SEMI-ACTIVE CONTROL

Domaine de référence : EMR
Auteur Park Semyung
Année de parution : 2019.
Type de document : Article de revue.
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Structural Performance Assessment of Offshore Wind Turbine Jackets-a Comparative Study Under Dynamic Loading Environment

Résumé : This work has focused on investigating the comparative performance of the conventional type of offshore jacket substructure and a modified twisted-tripod jacket type (MTJ) under static and dynamic loading environment. Conventional four-legged and four number of MTJ structures, with a finite number of leg twisting angles from 0° to 90°, for supporting 5 MW NREL wind turbine were analysed for a selected site. In order to compare performance under dynamic loading, the dimensions of the structures were designed iteratively using static stress analysis to ensure that all structures had a similar level of load-carrying capability. Static analyses were performed using SACS v8 and models were imported to SAP-2000 for dynamic response spectrum analyses. The results obtained here reveal that, in addition to savings in material costs, the modified twisted-tripod jacket performs more efficiently than conventional four-legged jackets. This study has established a framework of procedure for simplified analysis of wind turbine jackets under dynamic loading environment.
Domaine de référence : EMR
Auteur Desai Ravindra, Makwana Krishna, Potnis Sandeep, Pawar Prashant M., Ronge Babruvahan P., Balasubramaniam R., Vibhute Anup S., Apte Sulabha S.
Année de parution : 2019.
Mots-clés : Dynamic analysis, JONSWAP wave spectra, Offshore wind turbine, Static analysis, Twist angle, Twisted jackets (MTJ-structures).
Type de document : Article de colloque.
Source : Springer International Publishing
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Hydrodynamic characteristics of the modified V-shaped Semi-floating offshore wind turbine with heave plates

Résumé : In recent years, there is a great need to develop offshore wind energy on a global scale due to the greenhouse effect and energy crisis. Great efforts have been devoted to developing a reliable floating offshore wind energy technology to take advantage of the large amount of wind energy resources that exist in deep water. In this paper, a novel concept of a floating offshore wind turbine (FOWT), namely, the modified V-shaped semi-floating with heave plate, is proposed, and its hydrodynamic characteristics are studied. A numerical model based on ANSYS/AQWA is used to investigate the dynamic motion, response characteristics and mooring performance of the new concept. Moreover, the response amplitude operators (RAOs) of the different response quantities are also elaborated. A comparative study of the dynamic response of the different response quantities of the modified V-shape and original Vshaped semi-floating is carried out for operational environmental conditions. It is found that the modified V-shape semi-floating shows relatively better performance in platform motion and mooring line response.
Domaine de référence : EMR
Auteur Shi Wei, Zhang Lixian, You Jikun, Karimirad Madjid, Michailides Constantine
Année de parution : 2019.
Type de document : Article de revue.
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Methodology for modeling and service life monitoring of mooring lines of floating wind turbines

Résumé : Nowadays, the service life monitoring of mooring lines attracts more and more attention from the marine renewable energy (MRE) industry where developers desire to have a closer look on the safety margin. Besides, current standards are also being improved in order to ensure safe and cost-effective design for MRE devices. In the present study, we believe that monitoring and modeling should be implemented in parallel in order to better estimate the actual state and the reliability of the system during the expected service life. Besides, it is crucial to clarify the mechanic of the mooring line responses, to understand why and how they are modified during deployment, and how those can be accounted for in order to update the actual fatigue damage and predict the remaining allowable service life of system. A comprehensive modeling and service life monitoring methodology for mooring lines of floating wind turbines (FWTs) is discussed by the authors based on the reliability approach. Critical factors that influence structural behaviors such as material deterioration and marine environmental factors involved are identified and accounted for in this reliability-monitoring basis. Ultimately, based on the reliability level estimated, decisions regarding required maintenance or replacement of lines can be made.
Domaine de référence : EMR
Auteur Pham Hong-Duc, Schoefs Franck, Cartraud Patrice, Soulard Thomas, Pham Hien-Hau, Berhault Christian
Année de parution : 2019.
Mots-clés : Floating wind turbine, FLS, Mooring line, Reliability, Service life monitoring, ULS.
Type de document : Article de revue.
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A Mooring System Deployment Design Methodology for Vessels in Varying Water Depths

Résumé : In this paper, a methodology for designing mooring system deployment for vessels in varying water depths is proposed, in which the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is combined with a self-dependently developed vessel-mooring coupled program to find the optimal mooring system deployment considering station-keeping requirements and safety of the mooring system. Two case studies are presented to demonstrate the methodology by designing the mooring system deployments for a very large floating structure (VLFS) module and a semi-submersible platform respectively in three different water depths. It can be concluded from the obtained results that the mooring system can achieve a better station-keeping ability with relatively shorter mooring line when deploying in the shallow water. The safety factor of mooring line is mainly dominated by the maximum instantaneous tension increment in the shallow water, while the pre-tension has a decisive influence on the safety factor of the mooring line when deploying in the deep water.
Domaine de référence : EMR
Auteur Xu Shengwen, Liang Mingxiao, Wang Xuefeng, Ding Aibing
Année de parution : 2019.
Type de document : Article de revue.
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Three tidal turbines in interaction : An experimental study of turbulence intensity effects on wakes and turbine performance

Résumé : The development of marine current turbine arrays depends on the understanding of the interaction effects that exist between turbines in close proximity. Moreover, the ambient turbulence intensity also plays a major role in the behaviour of tidal turbines. Thus it is necessary to take ambient turbulence into account when studying interaction effects between several turbines. In order to highlight these interaction effects, experiments have been carried out in the IFREMER flume tank. These experiments focus on interactions between three horizontal axis turbines. This paper presents the experimental results obtained for three configurations with two ambient turbulence intensity rates. The results are presented in terms of turbine wakes and performance. The wake characterisation presents complex features for the three configurations and the lowest ambient turbulence rate: upstream turbines wakes are still present at the location of the downstream turbine and their wakes can interact or merge, depending on the tested configurations. On the contrary, for the highest turbulence rate, the downstream turbine wake is not affected in his shape by the two upstream ones which are not visible any more. In fact, as already observed in the previous studies of Mycek et al. [1, 2], the wake shape rapidly spreads out in the stream-wise direction behind the turbines. However, the velocity deficit and the turbulence intensity are higher for the downstream turbine comparing to the upstream ones. In terms of performance, one tested case presents an increase of the downstream turbine power production: when this turbine is exactly in the centre of the two upstream turbines and for the lowest turbulence rate only. A small misalignment of the layout axis with respect to the tidal current may result in a decrease of performance at the end. An analysis of the power spectral density functions of the downstream turbine torque and thrust shows that no signature of the upstream turbines can be found in these answers. Furthermore, the same spectral analysis carried out on the velocity measurements shows no signature of the upstream turbines either, from 3 diameters distance. This result is noticeable for the highest and the lowest tested turbulence cases and whatever the turbines configuration is.
Domaine de référence : EMR
Auteur Gaurier Benoît, Carlier Clément, Germain Grégory, Pinon Grégory, Rivoalen Elie
Année de parution : 2019.
Mots-clés : Array interaction, Experiment, Marine current turbine, Performance, Turbulence, Wake.
Type de document : Article de revue.
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Testing of Hydrophobically Coated Composite Materials With Marine Renewable Energy Applications

Résumé : Tidal turbine applications will place composite materials such as glass-fibre and carbon-fibre reinforced polymers under surprisingly high pressure due to the significant water depths they operate in (to depths of 50 m). The technical reliability of tidal turbines must be guaranteed despite the high dynamic loads resulting from a combination of plant operation, wind and waves with irregular swell. These external effects could lead to operation downtime and accelerated degradation. Research has already established that (unpressurised) moisture saturation is detrimental to both tensile and fatigue strength of GFRP material compared to its dry laminate performance. This degradation has been shown to be stress dependent. It is possible that hydrophobic coatings could help protect the material while in service. Therefore, two commercially available coatings were applied to 5 variations of composites materials. These materials are commonly used in tidal and wave turbine blades as they have excellent corrosion resistance and mechanical properties. All 5 are subjected to the same conditioning processes. Non-pressurised and pressurised immersion conditioning in water. Glass fibre epoxy (Ampreg), along with a glass fibre powdered epoxy, a glass fibre PEEK composite and a carbon fibre powdered epoxy composites were investigated. The glass-fibre epoxy (Ampreg) was also tensile tested statically/fatigue.
Domaine de référence : EMR
Auteur Walls Michael, O’Connor Heather, Dowling Denis P, Goggins Jamie
Année de parution : 2019.
Type de document : Article de revue.
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Fatigue of offshore structures : A review of statistical fatigue damage assessment for stochastic loadings

Résumé : Structural offshore fatigue can be accelerated way to reduce the time required for testing. In this regard, a statistical analysis of the loads must be performed to reduce loads with low damage contribution, while the uncertainties from external sources are retained. This process generates the spectrum required to perform the accelerated tests. Subsequently, the spectrum can be extrapolated, which increases the damage and reduces the testing time. In this work, a review of the main types of offshore structures is presented, including a description of the main statistical signal process analysis. In addition, a review of the damage model used in offshore analysis is presented. This can be modelled as a Gaussian or narrow-band process, depending on the variable amplitude loading which generates a random process due to waves.
Domaine de référence : EMR
Auteur Jimenez-Martinez Moises
Année de parution : 2019.
Mots-clés : Accelerated tests, Damage model, Durability, Offshore, Spectrum.
Type de document : Article de revue.
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Research on the damage prediction method of offshore wind turbine tower structure based on improved neural network

Résumé : Tower structure is a basic part of offshore wind power system, and how to ensure the stability and safety of tower structure in wind turbine operation and develop the efficient and accurate damage prediction method to judge the damage location and degree of tower structure has become an important research topic in the offshore wind power industry. With high adaptability, nonlinearity and strong function approximation ability, Artificial neural network (ANN) has been widely used in structural damage prediction and showed better performance than other diagnostic methods, however, traditional Back Propagation neural network (BPNN) has shortcomings of complex training parameters and low accuracy. To address this issue, this paper considered an improved neural network damage prediction method based on step-by-step identification for offshore wind turbine tower structure, an experimental research was carried out to simplify wind turbine model and experimentally measure the intact steel cylinders with different damage locations and different damage degrees. Then, the modal analysis was carried out by using the numerical analysis method and the results were compared with those of experimental measurement to modify the model. The training data are generated by Abaqus software to verify the proposed method. Results showed that the step-by-step prediction method could effectively reduce the complexity of the network, improve the prediction accuracy of the neural network, and save the training time.
Domaine de référence : EMR
Auteur Qiu Binbin, Lu Yang, Sun Liping, Qu Xianqiang, Xue Yanzhuo, Tong Fushan
Année de parution : 2019.
Mots-clés : ANN, Damage prediction, Generalized regression neural network, Genetic algorithm, Offshore wind turbine.
Type de document : Article de revue.
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Research on anti-collision of offshore wind turbine based on openfoam simulation

Résumé : Offshore wind farms are favored and valued by more and more countries because of their long availability of wind resources, high wind power density, small turbulence, zero emissions and proximity to load centers. However, the offshore wind farm is inevitably adjacent to or even interspersed with the waterway, the fishery, etc., and the wind turbine foundation has the risk of colliding with the relevant ship. Once a ship exceeding the anti-collision standard hits the fan foundation, it will cause partial damage or even collapse of the fan foundation, causing losses to the investor and may have certain adverse social impacts. The anti-collision investigation of offshore wind turbines is indispensable. It is important to accurately feedback the flow field information of the designated area of the wind turbine through software to calculate the annual collision probability of the ship. It is of great significance to implement navigation management measures, early warning measures and anti-ship collision protection measures.
Domaine de référence : EMR
Auteur Zhang Meiman
Année de parution : 2019.
Mots-clés : Àrees temàtiques de la UPC::Energies::Energia eòlica::Parcs eòlics, Àrees temàtiques de la UPC::Enginyeria civil::Enginyeria hidràulica, Àrees temàtiques de la UPC::Nàutica::Enginyeria naval, Energia eòlica, marítima i sanitària, Parcs eòlics marins.
Type de document : Article de revue.
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Probabilistic analysis of offshore wind turbines under extreme resonant response : Application of environmental contour method

Résumé : Offshore wind turbines can exhibit dynamic resonant behavior due to sea states with wave excitation frequencies coinciding with the structural eigenfrequencies. In addition to significant contributions to fatigue actions, dynamic load amplification can govern extreme wind turbine responses. However, current design requirements lack specifications for assessment of resonant loads, particularly during parked or idling conditions where aerodynamic damping contributions are significantly reduced. This study demonstrates a probabilistic approach for assessment of offshore wind turbines under extreme resonant responses during parked situations. Based on in-situ metocean observations on the North Sea, the environmental contour method is used to establish relevant design conditions. A case study on a feasible large monopile design showed that resonant loads can govern the design loads. The presented framework can be applied to assess the reliability of wave-sensitive offshore wind turbine structures for a given site-specific metocean conditions and support structure design.
Domaine de référence : EMR
Auteur Velarde Joey, Vanem Erik, Kramhøft Claus, Sørensen John Dalsgaard
Année de parution : 2019.
Mots-clés : Dynamic response, Environmental contour method, Marine structures, Offshore wind turbines, Probabilistic design, Reliability analysis.
Type de document : Article de revue.
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Impact of turbulence on power production by a free-stream tidal turbine in real sea conditions

Résumé : An experiment was performed to study the power production by a Darrieus type turbine of the Dutch company Water2Energy in a tidal estuary. Advanced instrumentation packages, including mechanical sensors, acoustic Doppler current profiler (ADCP), and velocimeter (ADV), were implemented to measure the tidal current velocities in the approaching flow, to estimate the turbine performance and to assess the effect of turbulence on power production. The optimal performance was found to be relatively high (Cp ∼ 0.4). Analysis of the power time history revealed a large increase in magnitude of power fluctuations caused by turbulence as the flow velocity increases between 1 and 1.2 m/s. Turbulence intensity does not alone capture quantitative changes in the turbulent regime of the real flow. The standard deviation of velocity fluctuations was preferred in assessing the effect of turbulence on power production. Assessing the scaling properties of the turbulence, such as dissipation rate, ε, the integral lengthscale, L, helped to understand how the turbulence is spatially organized with respect to turbine dimensions. The magnitude of power fluctuations was found to be proportional to L and the strongest impact of turbulence on power generation is achieved when the size of turbulent eddies matches the turbine size.
Domaine de référence : EMR
Auteur Sentchev Alexei, Thiébaut Maxime, Schmitt François G.
Année de parution : 2020.
Mots-clés : Tidal stream energy, Turbine performance, Turbulence, Velocity measurements.
Type de document : Article de revue.
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Bathymetry induced turbulence modelling the Alderney Race site : regional approach with TELEMAC-LES

Résumé : Les courants marins sont aujourd’hui considérés comme une source d’énergie renouvelable prometteuse. De nombreux projets internationaux consistent à installer différents types de convertisseurs d’énergie des courants marins. La caractérisation des ressources marines est alors essentielle pour optimiser cette production d’énergie. En particulier, les zones à fort potentiel hydrolien sont sujettes à une turbulence multi-échelles, allant de petits tourbillons capables de solliciter les pales en fatigue aux gros tourbillons pouvant perturber la production de la turbine. Une meilleure connaissance de la génération de ces tourbillons et de leur propagation est essentielle. C’est l’objet du projet ANR/FEM THYMOTE (Turbulence, Hydrolienne, Modélisation, Observations et TEsts en bassin) avec comme site d’étude le Raz Blanchard : l’un des sites les plus prometteurs d’Europe. L’une des questions posées concerne la capacité des grandes structures morphologiques du fond marin à produire des tourbillons. La méthode utilisée est l’emploi d’un modèle régional 3D pour couvrir la zone occupée par ces reliefs.Les modèles régionaux tels que TELEMAC-3D utilisent une fermeture turbulente de type URANS (Unsteady Reynolds Averaged Navier Stokes), avec par exemple le modèle k−ε. Cette approche ne permet pas une description fine des instationnarités de la turbulence. Cependant, grâce à l’augmentation des performances de calcul, la méthode Large Eddy Simulation (LES) devient envisageable. Celle-ci s’appuie sur un filtrage de l’écoulement, et consiste à simuler uniquement les plus grandes échelles de turbulence. Les plus petites, elles, sont modélisées. Le code TELEMAC-3D a été modifié durant cette thèse de manière à introduire cette fermeture turbulente. Le code développé permet de simuler des écoulements à surface libre en tenant compte d'une large gamme d'échelles allant de la turbulence à la propagation de la marée. Le code TELEMAC-LES a été validé sur la base de résultats expérimentaux issus de la littérature. Il est ensuite utilisé pour étudier les écoulements turbulents dans le Raz Blanchard grâce à une stratégie par emboîtement. La méthode LES permet alors une description fine de la turbulence de ces milieux, conduisant à l’identification de structures tourbillonnaires énergétiques, et donc la définition des zones les plus appropriées pour l’installation d'hydroliennes.
Domaine de référence : EMR
Auteur Adrien, Bourgoin
Année de parution : 2019.
Type de document : Thèse.
Source : LUSAC - Laboratoire Universitaire des Sciences Appliquées de Cherbourg
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Research on dynamic behavior of multistage gears-bearings and box coupling system

Résumé : The coupling dynamic model of the multistage gears transmission subsystem and the box subsystem is established. The static substructure method is used to extract the dynamic model parameters of the box. Study of the dynamic behavior of the gearbox coupling system shows, the acceleration of the rotors are mainly excited by gear meshing frequency and its harmonic, meshing frequency of the high-speed gears has a more obvious excitation effect on the system, gear meshing excitation is the cause of the rotor’s acceleration. It shows that the coupling model which is closer to the actual situation is helpful to the lightweight design of the system. The frequency amplitude of the low frequency region is significantly higher than the amplitude of the high frequency region for bearing force, which indicates that the external excitation caused by the cutting load is the main reason for the dynamic force of the system.
Domaine de référence : EMR
Auteur Lu Wenjia, Zhang Yimin, Cheng Hongchuan, Zhou Yang, Lv Hangyuan
Année de parution : 2019.
Mots-clés : bearing support force, box substructure system, coupling dynamics, dynamic meshing force, multistage gears transmission subsystem, static substructure method.
Type de document : Article de revue.
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Plus de références EMR


• Biocorrosion icone-flux-rss

Long term effect of strength and durability performance of concrete containing sulphate reduction bacteria under chloride condition

Résumé : The chloride ingress in concrete cause deterioration in concrete due reinforcement corrosion. Adding bacteria in concrete can improve material properties and increase durability with mechanism resist chloride ingress in concrete. Chloride ingress in concrete by bacteria is particularly suited for applications in chloride ion penetration in concrete. The research is objective to determine the effect of adding bacteria to the concrete properties. The bacteria used is locally isolated and enriched to suite concrete environment. The type of the bacteria used is identified as Sulphate Reduction Bacteria (SRB). The SRB is added into concrete mix with concentrations of 3%, 5% and 7%. The compressive and water penetration tests at 28th, 56th, 90th, 180th and the 360th day of curing period were conducted. Cubes of size 150mm × 150mm × 150mm were prepared for compressive strength and water penetration tests. The result of compressive strength shows significant strength of 66.3 MPa on the 360 of day. The water depth penetration also shows a significant impact with addition of SRB with 80% reduction of penetrated water into concrete compared to the control specimen. The overall results of bacteria showed promising results and further study on chloride condition capability is encouraging. It can be concluded that SRB with 5% addition was the optimum percentage to obtain the optimum strength and durability performances.
Domaine de référence : Biocorrosion
Auteur Irwan J M, Teddy T, Othman N, Khalid F S
Année de parution : 2020.
Type de document : Article de revue.
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Principles of Corrosion Processes

Résumé : In this chapter, principles of corrosion processes are illustrated with special emphasis on electrochemical aspects. Galvanic and electrolytic cells implicated in various corrosion and protection processes are analyzed with examples. Concentration cells are outlined with reference to galvanic corrosion and formation of differential aeration (oxygen) regions leading to pitting corrosion. Electrochemical kinetics and mixed potential theory are discussed. Active-passive transition in metals and alloys is brought out. Anodic and cathodic protection based on electrochemical principles find technological applications in industrial corrosion protection. Mechanisms involved in biofouling and microbially influenced corrosion are critically analyzed. Human body as a corrosion environment with reference to implanted biomaterials is also brought out.
Domaine de référence : Biocorrosion
Auteur Natarajan K. A., Vachtsevanos George, Natarajan K. A., Rajamani Ravi, Sandborn Peter
Année de parution : 2020.
Type de document : Chapitre de livre.
Source : Springer International Publishing
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Impact of environmental biofilms : Industrial components and its remediation

Résumé : The growth of technology and requirements globally for various commodities has brought about new challenges. Biofilms are aggregations of microbial cells, which contaminate and spoil industrial components and environments. These microbial cells with extracellular polymeric substances colonize living and nonliving surfaces and pose a serious problem for all industries, affecting their processes, leading to a reduction of product quality and economic loss. Industries, such as medical, food, water, dairy, wine, marine, power plants are exposed to biofilm formation. Pipe blockages, waterlogging and reduction of the heat-transfer efficiency, hamper the operating system of plants. Many industries do not set up remedial measures to control biofilm formation as they are not aware of this threat. Various conventional methods to control these biofilms are adopted by industries in their regular workflow, but these are temporary solutions. This calls for further research into remediation of the biofilm and its control for industrial components. This review article addresses the problems of biofilms and proposes solutions for various industrial components. Nanotechnology promises several options, and bring about a new aspect into the industrial economy, by solving the problems of environmental biofilms.
Domaine de référence : Biocorrosion
Auteur Vishwakarma Vinita
Année de parution : 2019.
Mots-clés : biofilm, environment, industry, nanotechnology, remediation.
Type de document : Article de revue.
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Oil reservoir simulating bioreactors : tools for understanding petroleum microbiology

Résumé : Various aspects of the oil fields in terms of microbial activity (souring, biocorrosion, etc.) and oil production (polymer flooding, etc.) have been evaluated through a variety of experiments. The primary step to study these properties in the laboratory requires the construction and operation of up-flow oil reservoir simulating bioreactors (ORSBs) in real time. Souring by reduction of sulfate to sulfide is a major contributor in enhancing corrosion of metal infrastructure used for oil production and processing. Whether the injection of biocides prevents or remediates reservoir souring can be addressed by flooding up-flow ORSBs. The potential of biopolymers/biosurfactants produced by different microbial strains have also been investigated for the role in maintaining additional oil recovery using ORSB. Additionally, key issues of polymer behavior during flooding of reservoirs could be understood during laboratory studies by monitoring the in situ porous medium rheology. Besides, the change in various ORSB parameters helps in adjudging the effect of different biosurfactants/biopolymers in enhancing oil recovery. Parameters such as permeability reduction, adsorption, interaction with porous matrix, and formation damage can be evaluated using ORSB. The analysis of earlier studies indicated that running bioreactors for longer duration of time can help in drawing conclusion with sharpness and less ambiguity. The current review discusses the construction and application of various types of ORSBs including the experimental studies employing ORSBs.
Domaine de référence : Biocorrosion
Auteur Rellegadla Sandeep, Jain Shikha, Agrawal Akhil
Année de parution : 2019.
Mots-clés : Biocides, Biopolymers, Bioproducts, Crude oil reservoir, Enhanced oil recovery, Sand pack bioreactors, Transport phenomena in bioreactors.
Type de document : Article de revue.
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Biogenic Iron Sulfide Nanoparticles Enable Extracellular Electron Uptake in Sulfate-Reducing Bacteria

Résumé : Microbes synthesize cell-associated nanoparticles (NPs) and utilize their physicochemical properties to produce energy under unfavorable metabolic conditions. Iron sulfide (FeS) NPs are ubiquitous and are predominantly biosynthesized by sulfate-reducing bacteria (SRB). However, the biological role of FeS NPs in SRB remains understudied. Here, we demonstrated that conductive FeS NPs function as an electron conduit enabling Desulfovibrio vulgaris Hildenborough, an SRB strain, to utilize solid-state electron donors via direct electron uptake. After forming FeS NPs on the cell surface, D. vulgaris initiated current generation coupled with sulfate reduction on electrodes poised at −0.4 V versus standard hydrogen electrode. Single-cell activity analysis showed that the electron uptake and metabolic rate via FeS NPs in D. vulgaris were 7-fold higher than those via native cell-surface proteins in other SRB. Our finding that FeS NPs enable cells to use solid electron donors under energy- limited conditions have implications on biogeochemical elemental cycling and microbial corrosion processes.
Domaine de référence : Biocorrosion
Auteur Deng Xiao, Dohmae Naoshi, Kaksonen Anna, Okamoto Akihiro
Année de parution : 2019.
Mots-clés : bioelectrochemistry, extracellular electron uptake, FeS nanoparticles, nanoscale secondary ion mass spectrometry, sulfate-reducing bacteria.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Study of an Antarctic thermophilic consortium and its influence on the electrochemical behavior of aluminum alloy 7075-T6

Résumé : Common alloys used for the manufacture of aircrafts are subject to different forms of environmental deterioration. A major one is corrosion, and there is a strong body of evidence suggesting that environmental microorganisms initiate and accelerate it. The development of an appropriate strategy to reduce this process depends on the knowledge concerning the factors involved in corrosion. In this work, a biofilm forming bacterial consortium was extracted in situ from the corrosion products formed in an aircraft exposed to Antarctic media. Two thermophilic bacteria, an Anoxybacillus and a Staphylococcus strain, were successfully isolated from this consortium. Two extracellular enzymes previously speculated to participate in corrosion, catalase and peroxidase, were detected in the extracellular fraction of the consortium. Additionally, we assessed the individual contribution of those thermophilic microorganisms on the corrosion process of 7075-T6 aluminum alloy, which is widely used in aeronautical industry, through electrochemical methods and surface analysis techniques.
Domaine de référence : Biocorrosion
Auteur Atalah Joaquín, Blamey Lotsé, Köhler Hans, Alfaro-Valdéz Ilda M., Galarce Carlos, Alvarado Claudia, Sancy Mamié, Páez Maritza, Blamey Jenny M.
Année de parution : 2019.
Mots-clés : aluminum alloy, biofilm, catalase, Corrosion, peroxidase, thermophiles.
Type de document : Article de revue.
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Self-healing and superhydrophobic coatings for corrosion inhibition and protection

Résumé : Corrosion of metal structures and consumer products has been a significant problem since the start of the industrial revolution. However, the inhibition and prevention of corrosion have only been an active area of study in the last century. The need for smart and functional coatings has recently become a large area of interest due to the ability of these coatings to be adapted to a variety of materials, mechanical and chemical conditions, and sporadic environmental conditions. One of the most viable methods by which corrosion can be prevented is through coatings. Self-healing coatings demonstrate a novel method of autonomic repair for microcracks using self-healing polymers encapsulated with polymerizable species into microparticles and nanoparticles. Additionally, these microparticles and nanoparticles can also be loaded with corrosion inhibitors that are released upon mechanical or chemical damage, thereby reducing corrosion. The use of superhydrophobic coatings leads to improved corrosion resistance due to the modification of the wettability of the coating, thereby changing its hydrophilic or hydrophobic response. This review details and provides a new perspective on self-healing and superhydrophobic coatings as well as future outlooks.
Domaine de référence : Biocorrosion
Auteur Manoj Arjun, Ramachandran Rahul, Menezes Pradeep L.
Année de parution : 2019.
Type de document : Article de revue.
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Eco-friendly Inhibitors for Corrosion Protection of Stainless steel : An Overview

Résumé : Corrosion is a major concern in the industrial application of ferrous alloys, this is as a result of the enormous cost involved in damages, maintenance and corrosion control. Stainless steels have high corrosion resistance capacity because of the existence of chromium, which forms a passive film layer of chromium-rich oxide in the presence of oxygen at lower temperatures; this forms a barrier against the surrounding. However, this layer could be damaged in aggressive environments. This necessitates attention from researchers worldwide for novel, cost effective, and environmental friendly corrosion prevention techniques. Inhibitors are extensively applied in the industry to minimize the corrosion degradation of metallic alloys; however, most inhibitors are hazardous and expensive. These toxic effects have led to the use of natural products as anticorrosion agents which are eco-friendly and harmless. This review briefly discusses some of the eco-friendly substances which are used as corrosion inhibitors for stainless steel in aggressive media.
Domaine de référence : Biocorrosion
Auteur Sanni Omotayo, Fayomi Ojo Sunday Isaac, Popoola Abimbola Patricia Idowu
Année de parution : 2019.
Type de document : Article de revue.
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Reduction of potential ennoblement of stainless steel in natural seawater by an ecofriendly biopolymer

Résumé : The effect of biofilm formation on passive stainless steel in seawater environments is of primary importance since it leads to potential ennoblement of surfaces and subsequently to localized corrosion such as pitting and crevice corrosion. This study aims at developing an ecofriendly alginate biopolymer containing both non-toxic calcium and a limited amount of biocidal zinc ions which inhibits this effect. For this purpose, calcium alginate containing less than 1% of zinc ions localized in the vicinity of the steel surface in natural and renewed seawater is demonstrated to reduce significantly the ennoblement process of steel. After 1 month of immersion, a mass loss of only 4% of the active material is observed authorizing thereby long-term protection of steel in real environment.
Domaine de référence : Biocorrosion
Auteur Abi Nassif L., Rioual S., Farah W., Hellio C., Fauchon M., Trepos R., Abboud M., Diler E., Thierry D., Lescop B.
Année de parution : 2019.
Mots-clés : Alginate, Antimicrobial, Biofilm, Biopolymer, Ennoblement, Steel.
Type de document : Article de revue.
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Corrosion assessment of a leakage pipeline in the seabed : A case study

Résumé : A pipeline in the seabed was successfully commissioned and had commenced production from the well. The pipeline has life time design for 20 years. However, a leakage from the flange connection was detected a couple months after start of production. The pipeline was isolated by closing the valves on the line tee, and shutdown the well production. This condition remains for 6 months before any remedial action was taken. During that period, it is believed that there is any corrosion mechanism occurred which might reduce the pipeline integrity. The paper briefly described the corrosion threats and assessed the corrosion rate of the leakage pipeline with limited information of factors that affecting corrosion rate. Additionally, recommendations for preparation of the pipeline to minimize internal risks are given.
Domaine de référence : Biocorrosion
Auteur Fatah M C, Diaz A, Darwin A
Année de parution : 2019.
Type de document : Article de revue.
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Corrosion Strategy in Oil Field System

Résumé : Crude oil is the main economic supply in many countries. Corrosion has been considered as the first fatal factor destroying the crude oil plants such as crude oil equipment, oil wells, separation vessels, storage tanks, and pipelines. This is the main reason encouraging many companies and researchers to develop new technological methods to manipulate corrosion. In this review, we discuss the types of corrosion, corrosion control methods (chemical and non -chemical methods), corrosion removal methods and corrosion monitoring process (direct and indirect measurement of corrosion). In addition some perspectives on SRB bacteria, types of inhibitors and gases removal methods were provided., Journal of Chemical Reviews (JCR)
Domaine de référence : Biocorrosion
Auteur Abdalsamed Ihssin Abubaker, Amar Ibrahim Ali, Altohami Fatima Ali, Salih Fatma Ali, Mazek Mazek Salh, Ali Masood Abdusalam, Sharif Abubaker Ahmed
Année de parution : 2019.
Type de document : Article de revue.
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Biocorrosion detection by sulphur isotopic fractionation measurements

Résumé : This innovative study presents a local diagnosis approach based on nanoSIMS technique to determine the biotic/abiotic origin of iron sulphides of (sub)micron size heterogeneously located in the corrosion product layers of iron. For iron coupons corroded in controlled conditions, negative δ34Ssulphides-sulphates were obtained in biotic conditions contrary to δ34Ssulphides-sulphates obtained in abiotic ones. These results underline that nanoSIMS is a reliable local technique to detect the formation origin of (sub)micron iron sulphides. This successful methodology was then applied to a complex system representative of an iron corroded in the conditions similar to those of radioactive wastes storage in geological medium.
Domaine de référence : Biocorrosion
Auteur Grousset S., Urios L., Mostefaoui S., Dauzeres A., Crusset D., Deydier V., Linard Y., Dillmann P., Mercier-Bion F., Neff D.
Année de parution : 2019.
Mots-clés : iron sulphide, microbiological corrosion, NanoSIMS, sulphur isotopic fractionation.
Type de document : Article de revue.
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Biocorrosion inhibition of Cu70:Ni30 by Bacillus subtilis strain S1X and Pseudomonas aeruginosa strain ZK biofilms

Résumé : Microbiologically influenced corrosion (MIC) or biocrorrosion is a cause of huge economic set back for industries around the globe. The present work deals with the study of corrosion of copper alloy (Cu–Ni 70:30) in the presence of bacterial biofilms produced by Bacillus subtilis strain S1X and Pseudomonas aeruginosa strain ZK. MIC was investigated using electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy, and through analytical techniques such as scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM). The Cu–Ni coupons were exposed to bacteria in minimal salt medium supplemented with NaCl for a period of 15 days. AFM and FTIR analysis revealed formation of a thick biofilm on the surface of the Cu alloy in bacterial inoculated systems. The electrochemical results demonstrated a decreased current density and corrosion rate for the systems with bacterial biofilms. These findings were supported by the results of SEM and weight loss studies. The results showed the inhibition of corrosion for Cu–Ni in biotic conditions (with biofilms) as compared with abiotic conditions (without biofilms).
Domaine de référence : Biocorrosion
Auteur Wadood Hafiz Zeshan, Rajasekar Aruliah, Farooq Ameeq, Ting Yen-Peng, Sabri Anjum Nasim
Année de parution : 2019.
Mots-clés : biofilm, Cu–Ni alloy, microbiologically influenced corrosion.
Type de document : Article de revue.
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BIOCIDES AND OTHER ANTIBACTERIAL MATERIALS IN POLYMERIZATION PROCESS FOR CONTACT BINDERS

Résumé : The theoretical part of the thesis introduces microbiological life and microbial control in water borne polymer dispersion in general. This section covers the most common biocides in use and the factors that influence their activity. The theory section also introduces laws and regulations governing the use of biocides and presents some "new generation" green antimicrobial materials. In the experimental part, the interaction between microbiological activity, the use of biocides and chemical variables in the preparation of polymer dispersion was investigated. In addition, the suitability of two antimicrobial biocidal products for the preservation of water borne dispersions was investigated. The antimicrobial products were chosen on the basis that chitosan is a purely biobased product. Chlorhexidine digluconate (CHX) was selected on the basis of other interesting research findings. In this thesis the following research methods were used: 1) measurement of cellular ATP content by luminometry, 2) Easycult assay, 3) biocide supplier stress tests, and 4) biocide and VOC concentration chromatographic assays. Based on the results obtained it was found that different chemical variables influenced the function of the biocides. For example, the changes in pH significantly affected the stability of a particular polymer dispersion and the ratio of redox chemicals significantly affected the degradation of the biocidal products. In addition, chitosan and chlorhexidine digluconate act as antimicrobial agents at low bacterial concentrations. At high bacterial concentrations, these agents did not protect the polymer dispersion products from the microbial contamination.
Domaine de référence : Biocorrosion
Auteur Koiranen Professor Tuomas
Année de parution : 2019.
Type de document : Article de revue.
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Synergistic Effect Between Sulfate-reducing Bacteria and Pseudomonas Aeruginosa on Corrosion Behavior of Q235 Steel

Résumé : Microbial community in nature is a whole in which the multiple species interact and restrict each other, leading to the metal corrosion as a synergistic result of microorganisms. In this paper, the corrosion behavior of Q235 steel in the culture media containing pure sulfate-reducing bacteria, Pseudomonas aeruginosa and their mixed cultures were analyzed by electrochemical methods and stereoscopic microscope. The results showed that the steel were subjected to corrosion to different degrees after immersion in the three cultures and with different characteristics. The corrosion of Q235 steel was the most severe in the pure SRB-containing culture, and then followed by that in pure PAO containing culture. The corrosion process of Q235 steel in the mixed cultures was more complicated. The corrosion was alleviated compared to that in pure strain system, indicating that the coexistence of mixed strains might change the effect on biocorrosion process.
Domaine de référence : Biocorrosion
Auteur Xi Guangfeng
Année de parution : 2020.
Type de document : Article de revue.
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External and Internal Corrosion and Its Control of Natural Gas Pipelines

Résumé : Natural gas pipelines suffer from both external and internal corrosion during their service life, which may result in dramatic consequences. In this research, external corrosion of X52 pipeline steel under direct current (DC) interference was investigated in a simulated soil solution. Corrosion acceleration by DC was quantitatively determined as a function of DC current density. DC was found to shift the cathodic protection (CP) potential to positive and negative directions in the anodic and cathodic zones, respectively, on the pipelines, resulting in either corrosion enhancement or hydrogen evolution at the zones. The effect of DC on properties and performance of fusion bonded epoxy (FBE) coating applied on pipelines was studied. The presence of DC interference facilitates water permeation into the coating due to the altered molecular structure and decreased the coating resistance for corrosion protection. Furthermore, corrosion of X52 pipeline steel under dynamic DC interference was investigated. Dynamic DC further accelerates the steel corrosion compared to static DC at specific DC current densities. It is believed that the alternating current (AC) component included in the pulse DC contributes to the corrosion reaction. With increase in the DC pulse frequency, corrosion rate of the steel decreases. The wave form of the dynamic DC does not obviously affect the steel corrosion. Internal corrosion of X52 pipeline steel was investigated in CO2-containing thin layers of solution, simulating the actual corrosive environment generated in the interior of natural gas pipelines. A mechanistic model was developed to explain the internal corrosion of wet gas pipelines. With the decrease of the solution layer thickness, the corrosion rate of the steel reduces. An elevated temperature accelerates the corrosion reaction kinetics, and generates a compact and homogeneous FeCO3 film at the same time. The presence of acetic acid increases the steel corrosion, while the methanol reduces corrosion rate of the steel. For external corrosion control, a micro/nanostructured ZnO-alkylamine composite coating was developed by electrodeposition and anodization to possess multiple functions. The optimal coating film is superhydrophobic, with the water contact angle up to 158o. The coating possesses a good corrosion resistance and excellent self-cleaning performance and a strong anti-adhesion to pseudomonas aeruginosa bacteria. For internal corrosion control, the inhibition performance of imidazoline (IM) and sodium dodecylbenzenesulphonate (SDBS) inhibitors and their synergism on corrosion of X52 steel in CO2-saturated chloride solutions was investigated. The synergistic effect of the two inhibitors enhances the corrosion inhibition performance, compared to the inhibitors acting independently. The adsorption of both inhibitors on the steel is chemisorption, following the Temkin adsorption isotherm.
Domaine de référence : Biocorrosion
Auteur Qian Shan
Année de parution : 2019.
Type de document : Article de revue.
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Electrochemical corrosion behaviors and mechanism of carbon steel in the presence of acid-producing bacterium Citrobacter farmeri in artificial seawater

Résumé : Acid-producing bacteria, which can induce variation in pH, play a key role in microbiologically influenced corrosion (MIC). In this study, the corrosion behavior of Q235 carbon steel was investigated in the presence of acid-producing bacterium Citrobacter farmeri. During the initial stage of bacterial adhesion, formation of inhomogeneous biofilm of C. farmeri produced differential aeration cells, resulting in the formation of tiny crevices on the carbon steel. After 168 h incubation, a thick biofilm of C. farmeri formed on the carbon steel, which accelerated the corrosion process and produced an inner layer of Fe3O4. The results suggested that the corrosion behavior of carbon steel in the presence of C. farmeri was determined by the formation of thick biofilm and conductive Fe3O4 film.
Domaine de référence : Biocorrosion
Auteur Tian Feng, He Xiaoyan, Bai Xiuqin, Yuan Chengqing
Année de parution : 2020.
Mots-clés : Acid-producing bacteria, Biofilm formation, Carbon steel, FeO, Microbiological corrosion.
Type de document : Article de revue.
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Microbiologically influenced corrosion of marine steels within the interaction between steel and biofilms : a brief view

Résumé : Marine is the harshest corrosive environment where almost all marine underwater equipment and facilities undergo corrosion caused by marine microorganisms. With the development of marine resources globally, the marine engineering and relevant infrastructures have increased exponentially. Microbiologically influenced corrosion (MIC) leads to severe safety accidents and great economic losses. The specific aggregation of corrosive microbial communities and their interactions with materials conform to a typical ecological adaptation mechanism. On the one hand, corrosive biofilms in the marine environment selectively colonize on a specific steel substrate by utilizing their complex community composition and various extracellular polymeric substances; on the other hand, the elemental composition and surface microstructure of different engineering steels affect the microbial community and corrosive process. MIC in the marine environment is a dynamic process evolving with the formation of corrosive biofilms and corrosion products. In this mini-review, the interactions between corrosive biofilm and steel substrates are explored and discussed, especially those conducted in situ in the marine environment. Herein, the important role of iron in the dynamic process of marine corrosion is highlighted.
Domaine de référence : Biocorrosion
Auteur Ma Yan, Zhang Yimeng, Zhang Ruiyong, Guan Fang, Hou Baorong, Duan Jizhou
Année de parution : 2019.
Mots-clés : Biocorrosion, Biofilms, Corrosive mechanisms, Marine, Microbiologically influenced corrosion, Steel corrosion.
Type de document : Article de revue.
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Effect of biocides on highly corrosive methanogenic Archaea

Résumé : Biocide mitigation strategies of microbiologically influenced corrosion (MIC) in the oil and gas industry have been primarily used to eliminate the growths of sulfate-reducing microorganisms (SRM). However, methanogenic Archaea (MA) can also be highly corrosive by using iron as an electron source for methanogenesis. Because of the fundamental physiological differences between archaea and bacteria, responses of MA towards SRM-specific biocides cannot be deduced using SRM. Due to the lack of information available on the effect of biocides on corrosive MA, we selected THPS, glutaraldehyde, nitrate and perchlorate to compare against corrosive SRM. Preliminary results showed that at low concentrations of THPS (0-10 ppm), growth of MA was not affected, methane production and corrosion rates (0.1 mm/yr) were comparable between the different THPS concentrations. On the contrary, the SRM strain showed decreased corrosion rates (0.18 mm/yr to 0.03 mm/yr) with increasing THPS concentrations. Further corrosion tests including electrochemical measurements of different biocides on the growth of MA and SRM will be conducted. Such knowledge not only provide important insights on the physiological response of MA to biocides but also contribute to more effective mitigation strategies that can be both economic and environmentally beneficial.
Domaine de référence : Biocorrosion
Auteur An Biwen Annie
Année de parution : 2019.
Type de document : Article de revue.
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Impact and Role of Bacterial Communities on Biocorrosion of Metals Used in the Processing Industry

Résumé : In the present study, the effects of the corrosive bacterial community and the biofilm on cooling water systems made from mild steel (MS) and brass (BR) were studied under field exposure conditions using electrochemical impedance spectroscopy measurements, scanning electron microscope, and X-ray diffraction methods. Results from16S rRNA gene sequences showed that the predominant bacteria species detected in the biofilm of MS and BR metals during 360 days of exposure were Bacillus cereus EN14, Achromobacter xylosoxidans EN15, A. xylosoxidans EN16, and B. cereus EN17. The weight loss results revealed that a higher corrosion rate was observed in MS (0.7 ± 0.1 mm/y) compared with that in BR (0.17 ± 0.05 mm/y) at the end of the exposure period. This can be explained by the bacterial communities enhancing the corrosion rates by creating a local corrosive environment. Scanning electron microscope images revealed the adsorption of biofilm on the MS and BR surfaces following180 days of exposure. From the electrochemical impedance study, a higher charge transfer resistance (Rct) was obtained for BR (119.6 Ω cm2) when compared with that of MS (43.4 Ω cm2). This study explains the role of bacterial communities and their mechanisms in the corrosion of MS and BR in cooling water systems.
Domaine de référence : Biocorrosion
Auteur Narenkumar Jayaraman, AlSalhi Mohamad S., Arul Prakash Arumugam, Abilaji Subramani, Devanesan Sandhanasamy, Rajasekar Aruliah, Alfuraydi Akram A.
Année de parution : 2019.
Type de document : Article de revue.
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Characterization of biodeteriorating microorganisms in buildings in Bucaramanga, Colombia

Résumé : The action of the microorganisms upon the integrity of the constructing material is termed Biodeterioration, concrete resistance to the action of the microorganisms is considered an indirect measurement of its durability and could be used as a marker of the integrity of the structure. In Colombia, the studies considering this parameter are rare. The objective of this study was to isolate and characterize the microbial communities present in areas with evident deterioration in the selected buildings. To accomplish this, isolation, culturing and molecular identification of the isolates was performed. Results showed that Cladosporium spp, Aspergillus spp, Mucor spp, Penicillium spp, Penicillium spp, Rhizopus spp, Fusarium spp, Geotrichum spp, and bacterial genera such as Bacillus spp and Amphibacillus spp, coexist within the biofilms sampled. This study is a description and a starting point to deepen the characterization of these communities and to understand the role they perform in the integrity of the building materials considering the climatic and environmental conditions.
Domaine de référence : Biocorrosion
Auteur Mantilla K, Suárez-Barrera M, Rueda-Forero N J, Guarín O D, Gómez F R, Durán S M, Tiria L C
Année de parution : 2019.
Type de document : Article de revue.
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Effect of surface topography and chemistry on the attachment of bacteria on solid surfaces

Résumé : Microbiologically induced corrosion due to bacterial biofilms causes several problems in industrial systems, technical applications and in medicine. Prior to the formation of a biofilm on a substrate, planktonic cells attach on the surface. Hence, the properties of the surface play a key role in biofilm formation and are of great importance for the development of strategies to prevent bacterial attachment and biofilm formation. This project aims at clarifying to which extent surface micro-/nanostructuring and chemical functionalization affects bacterial attachment and whether a synergistic combination of the two can be used to control bacterial adhesion. To answer these questions, model surfaces with regular patterns of 5-10 micrometers in size have been prepared, which provide distinct zones differing in terms of their chemistry or nano-roughness. This was achieved by micro contact printing of self-assembled monolayers with different functional groups and deposition of patterned ZnO nanorod arrays for studying the effect of surface chemistry and morphology, respectively. Typical contrasts studied were combinations of positively/negatively charged, hydrophobic/hydrophilic or flat/rough. The attachment behavior of bacteria on tailored surfaces were studied in a flow chamber as a function of time. The strain Pseudomonas fluorescens SBW25 was chosen as a model organism. DNA-intercalating dyes such as Syto9 have a high affinity to adsorb on ZnO nanorods. To overcome this limitation a genetic modification was performed by introducing a gene which expresses a green fluorescent protein in P. fluorescens SBW25 enabling the quantitative evaluation of the flow chamber studies by means of fluorescence microscopy. Further analysis of the attachment behavior was performed by means of scanning electron microscopy. The presentation will summarize the results of our systematic study on the role of individual parameters on bacterial attachment and highlight synergistic combinations, showing an inhibition or enhancing effect. As the investigations with model substrates enable a precise control of the surface parameters, this approach can be applied to different microorganisms and material systems to achieve a correlative description of bacterial adhesion on solid surfaces.
Domaine de référence : Biocorrosion
Auteur Schütter Jan
Année de parution : 2019.
Type de document : Article de revue.
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Degradation of organic contaminants and steel corrosion by the dissimilatory metal-reducing microorganisms Shewanella and Geobacter spp.

Résumé : Shewanella and Geobacter are the two genera of dissimilatory metal-reducing microorganisms that can couple intracellular oxidation of organic matter to extracellular reduction of oxidized metal ions, such as solid-phase iron (Fe(III)) and manganese (Mn(IV) (hydr)oxides. To transfer electrons extracellularly, both Shewanella and Geobacter spp. possess pathways that transfer electrons from the quinone/quinol pool in the cytoplasmic membrane, across the cell envelope to the extracellular Fe(III) and Mn(IV) (hydr)oxides. In addition, Geobacter spp. use electrically conductive pili and/or filaments that consist of multiheme c-type cytochromes for long-distance electron transfer to Fe(III) and Mn(IV) (hydr)oxides and other electron acceptors. Furthermore, the Fenton reaction driven by Shewanella oneidensis MR-1 can be used to degrade a variety of organic contaminants. Some Geobacter spp., such as Geobacter metallireducens GS-15, couple oxidative degradation of benzine, phenol and other aromatic contaminants to Fe(III) reduction. Moreover, other Geobacter spp., such as G. loveleyi SZ, also couple oxidation of organic matter to reductive dichlorination of organohalide contaminants. Finally, under anoxic condition, Shewanella and Geobacter spp. corrode carbon steel by direct oxidation. This review focuses on our current understandings of extracellular electron transfer mechanisms of as well as degradation of organic contaminants and steel corrosion by Shewanella and Geobacter spp.
Domaine de référence : Biocorrosion
Auteur Jiang Zhou, Shi Meimei, Shi Liang
Année de parution : 2020.
Mots-clés : Biocorrosion, Biodegradation, Extracellular electron transfer, Flavin-base electron bifurcation.
Type de document : Article de revue.
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Microbiologically influenced corrosion mechanism of 304L stainless steel in treated urban wastewater and protective effect of silane-TiO2 coating

Résumé : Microbiologically influenced corrosion (MIC) of bare and silane-TiO2 sol-gel coated stainless steel (SS) was studied in treated urban wastewater (TUWW). Combining the electrochemical impedance spectroscopy (EIS) and the scanning vibrating electrode technique (SVET) showed that SS surface colonization occurs, at earlier stages, by iron-oxidizing bacteria (IOB), and later by sulphate-reducing bacteria (SRB). The SVET results showed that chemical corrosion process and bacterial respiration led to the depletion of dissolved oxygen, creating a differential aeration cell and thus a localized corrosion phenomenon. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that the growth of a bacterial biofilm on 304L SS was a dynamic process, stimulating the localized oxidation of SS. To improve corrosion protection, a silane-TiO2 sol-gel coating for SS is proposed. SEM showed that the coating reduced bacterial adhesion and EIS study demonstrated that the coating improved the barrier properties and corrosion resistance of 304L SS in TUWW over a short period of immersion.
Domaine de référence : Biocorrosion
Auteur Ziadi I., Alves M. M., Taryba M., El-Bassi L., Hassairi H., Bousselmi L., Montemor M. F., Akrout H.
Année de parution : 2019.
Mots-clés : bacterial adhesion, EIS, MIC, silane-TiO coating, stainless steel, SVET.
Type de document : Article de revue.
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Pyocyanin-modifying genes phzM and phzS regulated the extracellular electron transfer in microbiologically-influenced corrosion of X80 carbon steel by Pseudomonas aeruginosa

Résumé : In Pseudomonas aeruginosa, phzM and phzS genes encode two enzymes that convert phenazine‑1‑carboxylate to pyocyanin (PYO), which is an efficient mediator for EET. Herein, an aerobic P. aeruginosa mutant strain with phzM and phzS genes knockout was used to confirm that phzM and phzS genes regulate EET-MIC of X80 carbon steel. The inhibition efficiency of MIC by mutant strain reached ∼48 %, demonstrating that MIC was considerably suppressed since the mutant strain was no longer capable of producing sufficient PYO. When organic carbon was deficient, P. aeruginosa could utilise iron as an electron donor and caused more severe corrosion via EET.
Domaine de référence : Biocorrosion
Auteur Huang Luyao, Huang Ye, Lou Yuntian, Qian Hongchang, Xu Dake, Ma Lingwei, Jiang Chengying, Zhang Dawei
Année de parution : 2019.
Mots-clés : Extracellular electron transfer, Microbiological corrosion, Phenazine derivatives, Pyocyanin.
Type de document : Article de revue.
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Biocorrosion Behavior of AISI 1006 Carbon Steel Protected by Biofilm of Bacillus subtilis by an Iron-Oxidizing Bacterium and a Sulfate-Reducing Bacterium

Résumé : An investigation of microbiologically induced corrosion was carried out on AISI 1006 carbon steel using Acidithiobacillus ferroxidans and Citrobacter murliniae. This study was aimed to compare the resultant corrosion by the two bacteria for 7 and 21 days, either in the presence or in the absence of Bacillus subtilis as a metal corrosion inhibitor. According to the weight-loss experiment, there was no significant difference in weight loss (within the range of 4–5%). However, SEM results showed contrast corrosion surfaces occurring, uniform and pitting corrosion for those bacteria. Major damages were observed during a longer period of immersion to bacterial cultures.
Domaine de référence : Biocorrosion
Auteur Widyanto Bambang, Chaerun Siti Khodijah, Hartomo Wahyu Ardi, Rizki Intan Nurul
Année de parution : 2019.
Mots-clés : AISI 1006, Bacterial biofilm, Corrosion control, Iron-oxidizing bacteria (IOB), Microbiologically induced corrosion (MIC), Sulfate-reducing bacteria (SRB).
Type de document : Article de revue.
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Models for prediction of long-term corrosion of cast iron water mains

Résumé : Corrosion of cast iron pipes buried in wet soils has long been associated with severe localized effects often attributed to microbiological influences and also with the chemical and physical properties of the soils. Despite more than 70 years of research effort, correlations have remained poor. Recently the reasons for this have been elucidated, as reviewed briefly herein. Also, interpretation of data from actual cast iron pipes buried in a variety of soils for up to 129 years, shows that two critical factors governing depth of local corrosion penetration are the type of soil and the compaction of that soil around the pipe. The latter influences the size of wet air-voids in the soil at the pipe surface. These cause differential aeration and associated severe localized corrosion. The other critical factor is the time of wetness of the soil-metal interface. This is related both to atmospheric precipitation (e.g. rain) and to soil permeability as governed by compaction. Microbiological corrosion has no influence unless essential nutrients continue to be available. These new views on an old subject permit the development of corrosion penetration models for longer-term corrosion.
Domaine de référence : Biocorrosion
Auteur Melchers Robert
Année de parution : 2019.
Type de document : Article de revue.
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Biofilms : The Good and the Bad

Résumé : Biofilms are well-structured, cooperating microbial communities adhered to various types of surfaces. Microbes forming biofilms secrete slimy extracellular polymeric substances (EPSs) which provide biofilms with their resistance against antibiotics. Biofilms have several advantages and disadvantages. Exploring the negative side of biofilms first—biofilm formation interferes in crucial processes like heat and mass transfer, fluid dynamics, and also causes bio-corrosion thereby increasing maintenance costs and decreasing the overall yields from plants. Bio-corrosion also increases the chances of bacterial adhesion and contamination of processed food products, dairy products, and brewing products. Biofilms affect the sea food and aquaculture industries by clogging cages and interfering with nutrient inflows. Biofilms have numerous harmful effects that are associated with the medical industry, such as infections associated with the insertion of tubes, catheters, and valves, as well as surgery. Considering the positive aspects of biofilms we note that the judicious use of biofilms can provide solutions to modern day problems. They can be effectively used for the bioremediation of soil and groundwater as well as being used to treat oil spills. They provide cost-effective alternatives in the mining industry in the form of bioleaching and biofilm-based bioreactors for municipal/industrial waste disposal. Biofilms can be used as biosensors for the reliable and quick detection of chemicals as well as in the treatment of contaminated water.
Domaine de référence : Biocorrosion
Auteur Yadav Suresh K., Sanyal Somali, Kumar Sunil, Chandra Niharika, Singh Leena, Hashmi Muhammad Zaffar, Varma Ajit
Année de parution : 2019.
Mots-clés : Bio-corrosion, Biofilm, EPS, Oil spillage, Remediation.
Type de document : Chapitre de livre.
Source : Springer International Publishing
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Corrosion behavior and mechanism of carbon steel influenced by interior deposit microflora of an in-service pipeline

Résumé : Investigation of carbon steel corrosion influenced by in-situ microbial communities can provide reliable information about microbiologically influenced corrosion (MIC) in the oil and gas field. Here, we investigated the 90-day corrosion behavior of Q235 carbon steel influenced by interior deposit microflora of an in-service pipeline using open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). Linear sweep voltammetry (LSV), 16S rRNA gene sequencing, and surface analysis were used to comprehensively analyze the corrosion mechanisms. The results indicated that OCP was decreased while the charge transfer resistance (Rct) was increased, and that steel corrosion was inhibited during the first 45 days. Subsequently, OCP was significantly increased while Rct was rapidly decreased, and steel corrosion was enhanced. After 90-day immersion, severe pitting corrosion with a maximum pit depth of 89.6 μm occurred on the steel surface. Viable microbes in the final biofilm significantly increased the cathodic current. Iron carbonate, chukanovite and cementite were identified as the main corrosion products on the steel surface. Methanobacterium dominated the final biofilm community. These observations indicate that the corrosion mechanism of the final biofilm can be explained by extracellular electron transfer MIC in which microbes corrode steel by direct electron uptake.
Domaine de référence : Biocorrosion
Auteur Su Hong, Tang Ruohao, Peng Xiaowei, Gao Aiguo, Han Yejun
Année de parution : 2019.
Mots-clés : 16S rRNA sequencing, Carbon steel, direct electron uptake, EIS, microbiologically influenced corrosion, polarization.
Type de document : Article de revue.
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Sensing the unreachable : challenges and opportunities in biofilm detection

Résumé : Bacteria can attach to essentially all materials and form multicellular biofilms with high-level tolerance to antimicrobials. Detrimental biofilms are responsible for a variety of problems ranging from food and water contamination, bio-corrosion, to drug resistant infections. Besides the challenges in control, biofilms are also difficult to detect due to the lack of biofilm-specific biomarkers and methods for non-destructive imaging. In this article, we present a concise review of recent advancements in this field, with a focus on medical device-associated infections. We also discuss the technologies that have potential for non-destructive detection of bacterial biofilms.
Domaine de référence : Biocorrosion
Auteur Xu Yikang, Dhaouadi Yousr, Stoodley Paul, Ren Dacheng
Année de parution : 2020.
Type de document : Article de revue.
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Assessment of internal corrosion mechanisms in a natural gas pipeline containing black powder

Résumé : A 30” Diameter X 135 km long cross country pipeline was laid for transfer of natural gas from an upstream gas pipeline to the end users. This pipeline is being used for delivery of natural gas to customers in power generation. Natural gas is imported and brought to several ports in the Liquefied condition and is gasified for transportation to end consumers. This natural gas is supposed to be dry in such situations. However, despite no evidence of water, large quantity of black powder was observed in the pipeline during pigging operations. Such quantity of black powder is not supposed to be present in a dry gas pipeline. Black powder has made the intelligent pigging extremely difficult and hence has made the corrosion assessment difficult using an Inline Inspection tool. Operational and monitoring data was studied extensively for identification of driving mechanisms which is primarily responsible for generation of black powder. After identification of major driving mechanism, remediation measures are being implemented for removal of black powder and mitigation of internal corrosion.
Domaine de référence : Biocorrosion
Auteur Gupta Saumitra Shankar, Agarwal Deepak
Année de parution : 2018.
Type de document : Article de revue.
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Microbiological analysis of muck and oil samples to identify major corrosion causing bacteria

Résumé : The accelerated deterioration of metal pipelines by microorganisms, referred to as Microbiologically Influenced Corrosion (MIC), is attributed to the formation of a biofilm on the surfaces constituting a mixed population of bacteria, archaea and fungi that synergistically act on the metal. Various mechanisms of corrosion involve physiologically different groups of microorganisms that can act either aerobically or anaerobically and can enhance corrosion either directly or indirectly. The exact types of bacteria implicated in a particular case depends on the nature of the material transported through the pipelines, the environmental conditions, the content of certain impurities e.g. sulphur content, moisture content etc. The bacterial groups implicated in MIC are the anaerobic sulphate reducing bacteria (SRB), iron bacteria in association with others such as heterotrophic bacteria, hydrocarbon degrading and sulphur oxidizing bacteria. In the present study enumeration of different bacteria from pipeline muck and crude oil samples was carried out using group specific selective media in which it was found that counts for most of the groups was higher in muck samples compared to crude oil.
Domaine de référence : Biocorrosion
Auteur Telang Swati, Shaikh Reshma, Nerurkar Anuradha, Yama Mohan, Rawat Jaya, Archana G
Année de parution : 2018.
Type de document : Article de revue.
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Prediction of Souring in Infill Wells using Standalone Extended 2D Simulator for a Malaysian Offshore Field

Résumé : Abstract Hydrogen sulfide (H 2 S) production in a sea water injected, high temperature offshore reservoir is causing concern, because the existing wells and facilities are not designed for sour service. This is challenging for the design and materia
Domaine de référence : Biocorrosion
Auteur Salleh Intan Khalida, Panuganti Sai Ravindra, Misra Sanjay, M Ibrahim Jamal Mohamad, Hamza Norashikin, Sorbie Kenneth Stuart, Cruickshank John, Tewari Raj Deo
Année de parution : 2019.
Type de document : Article de colloque.
Source : Society of Petroleum Engineers
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Corrosion resistance of hot-dip galvanized steel in simulated soil solution : A factorial design and pit chemistry study

Résumé : The soil corrosion of widely applied galvanized steel structures, such as power transmission towers, must be considered to prevent harm to their structural integrity and the high costs associated with early failure. A full two-level factorial design was used to evaluate the relative significance of influencing factors on the underground corrosion of hot-dip galvanized steel. Experiments were performed in simulated soil solutions. The influence of temperature, chloride, sulfate, bicarbonate and citric acid concentration was evaluated using statistical analysis of the results. Using analysis of variance, temperature, citric acid and chloride were found to be individually significant. Also, temperature/citric acid and temperature/chloride significantly interacted to increase the corrosion rate. The lead-in pencil electrode technique was used to further evaluate the impact of above mentioned factors on the dissolution behavior of Zn coating. The results revealed that chloride and citric acid affect salt film formation at the pit bottom, while temperature alters the dissolution kinetics by changing the diffusion coefficient of the dissolving Zn (II) species. Moreover, the effect of bulk solution dissolved oxygen concentration on the corrosion rate of the galvanized steel was modeled. It was found that oxygen solubility does not have a dominant effect on the overall corrosion behavior of galvanized steel. Rather, the effect of temperature is dominant.
Domaine de référence : Biocorrosion
Auteur Nakhaie D., Kosari A., Mol J. M. C., Asselin E.
Année de parution : 2019.
Mots-clés : Artificial pit, Factorial design, Galvanized steel, Simulated soil solution, Soil corrosion.
Type de document : Article de revue.
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Microbiologically assisted cracking of X70 submarine pipeline induced by sulfate-reducing bacteria at various cathodic potentials

Résumé : In this study, slow strain rate tests and electrochemical techniques were used to investigate the microbiologically assisted cracking (MAC) behavior of X70 pipeline steel induced by sulfate-reducing bacteria (SRB). Various potentials, i.e. open circuit potential (OCP), -850 mV, -1000 mV, and -1200 mV (vs. SCE), were applied to simulate the invalid cathodic protection potentials which may appeared in engineering. The results showed that SRB facilitated the corrosion rate at OCP, and that MAC induced by SRB exists at all applied potentials but the reasons differ with the applied potentials. At OCP, the mechanism of stress corrosion cracking (SCC) was anodic dissolution and SRB-assisted pitting promoted cracks nucleation. At strong cathodic potentials, such as -1000 mV and -1200 mV, the mechanism of SCC was dominated by hydrogen embrittlement and SRB promoted hydrogen permeating into steel by the poison effect of sulfide produced by metabolic activity. At -850 mV, the mechanism of SCC transformed from anodic dissolution to hydrogen embrittlement. Thus, the reason of MAC at -850 mV comes from the two aspects.
Domaine de référence : Biocorrosion
Auteur Wu Ming, Sun Dongxu, Gong Ke
Année de parution : 2019.
Mots-clés : Cathodic potential, Microbiologically assisted cracking, Pipeline steel, Stress corrosion cracking, Sulfate-reducing bacteria.
Type de document : Article de revue.
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Determination of sulfide production by Reducing Bacteria isolated in the injection water of an Iraqi oil field

Résumé : Several oilfields undergo to reservoir souring, typically during water injection for secondary recovery, resulted in increasing concentrations of produced hydrogen sulfide (H2S). The main reason for this is the mechanism of generating hydrogen sulfide are the sulfate reducing bacteria (SRB). These bacteria use sulfate (So4) in the injection water as an electron acceptor and use organic acids which exist in formation water as a source of energy and carbon to generate H2S. In addition to that, the issues of health and safety, the existence of H2S decreases the worth of the produced hydrocarbon. The present study includes isolation and enumeration of sulfate reducing bacteria (SRB) from the injection and produced water of Ahdeb oilfield in Iraq by using Most Probable Number (MPN) technique. The Laboratory experimental work for production of sulfide with mix cultures of these bacteria was performed also with sodium lactate as an energy source. The experiments were carried out to determine the concentration of sulfide versus consumption of lactate in vitro. The concentration of sulfide is determined by using spectrophotometer method, whereas; the concentration of sodium lactate is calculated by using high performance liquid chromatography (HPLC) system. The experimental results demonstrates that the most numbers of bacteria in injection water are higher than the number in produced water samples. Whilst, the production of sulfide by SRB presents that inversely correlated to the concentration of sodium lactate. The growth experiments shows that the SRB concentration is increased in areas where the energy source and sulfate have high concentrations. Also, there is a direct relationship between SRB concentration and sulfide production. Therefore, the water injection from these bacteria must be treated before the injection to the reservoir to provide all the condition of SRB growth.
Domaine de référence : Biocorrosion
Auteur Mahdi Najwa H, Al-Tamimi Wijdan H, Al-Jawad Mohammed S
Année de parution : 2019.
Type de document : Article de revue.
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Corrosion Behaviour of 2205 Duplex Stainless Steel in Oilfield Production Fluid Containing Sulphate-reducing Bacteria

Résumé : The corrosion behaviour of 2205 duplex stainless steel (DSS) in sulphate reducing-bacteria (SRB)-free and SRB-containing oil-field production fluid are performed via electrochemical techniques, microscopic imaging, and X-ray photoelectron spectroscopy (XPS). The results show that the corrosion morphology of 2205 DSS in oil field production fluid is pitting corrosion, and the pit becomes deeper in case of bacteria. The corrosion mechanism of 2205 DSS varies depending on the SRB growth stage. Corrosion is inhibited in the steady growth stage, but it is greatly accelerated during the other stages. Observed results of XPS demonstrate that the passivation film obtained in the presence of SRB comprises sulphides of Cr and Fe. The sulphide-containing passivation film is more easily penetrable by aggressive anion and the local corrosion is accelerated compared to the sulphide-free passivation film.
Domaine de référence : Biocorrosion
Auteur School of Petroleum Engineering, Liaoning Shihua University, Fushun 113001, China, Chen Xu
Année de parution : 2019.
Type de document : Article de revue.
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Phenomena and theories in corrosion science : methods of prevention

Domaine de référence : Biocorrosion
Auteur Gergely András
Année de parution : 2019.
Mots-clés : Corrosion and anti-corrosives, Protective coatings.
Type de document : Livre.
Source : Nova Science Publishers
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Microbial Corrosion of C1018 mild steel by a halotolerant consortium of sulfate reducing bacteria isolated from an Egyptian oil field

Résumé : In this study, a consortium of halotolerant sulfate reducing bacteria (SRB) was obtained from a water sample collected from an Egyptian oil-field. North Bahreyia Petroleum Company (NORPETCO) is one of the petroleum companies that suffer from severe corrosion. The present study aim to investigate the microbial structures of this consortium and their potential contributed to microbial corrosion. Dissimilatory sulfite reductase dsrAB gene sequences analysis indicated that the mixed bacterial consortium contained two main phylotypes: members of the Proteobacteria (Desulfomicrobium sp., Desulforhopalus sp., and Desulfobulbus sp.) and Firmicutes (Desulfotomaculum sp.). Mild steel C1018 coupons were incubated in the presence of SRB consortium for a period of 35 days, the evolution of corrosion was studied using weight loss and dissolved sulfide production of SRB consortium. Results indicated that, the corrosion rate in the presences of SRB was approximately 15 times of that for the control. Furthermore, sessile cells (biofilm) and subsequent corrosion products that developed were characterized by scanning electron microscope coupled with energy dispersive X-ray spectroscopy (EDX).
Domaine de référence : Biocorrosion
Auteur Abdel Khaliek Wafaa Abdel Fattah, Labena Wafaa, Mohamed Tarek n, Elsawy Hany, Farahat Laila A
Année de parution : 2019.
Type de document : Article de revue.
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Nanowall enclosed architecture infused by lubricant : A bio-inspired strategy for inhibiting bio-adhesion and bio-corrosion on stainless steel

Résumé : Microbiologically influenced corrosion (MIC) severely deteriorates metal material in seawater environment. Finding versatile coatings to inhibit bioadhesion and biocorrosion is a critical option to avoid degradation by microorganisms. Inspired by Nepenthes pitcher, this study prepares lubricant-infused surface (LIS) by using a three-step method: electrodeposition, vapor deposition, and oil infusion. First, Co(OH)2 is built on stainless steel (SS) via electrodeposition. The wrinkled nanowall circumvents the partition architecture, thus producing a highly porous structure. Second, through dodecanethiol modification, the combination of anchored hydrophobic moiety and porous structure creates a lotus-inspired superhydrophobic (SHP) surface. Third, oil infusion produces LIS. The independent partition architecture increases the anchoring effect to oil phase, thereby enhancing the stability. After immersion for 28 days in an abiotic seawater environment, the corrosion current density of SS covered by LIS SS is as low as 2.52 × 10−10 A/cm2, which is approximately fivefold lower than that of bare SS. After immersion in sulfate-reducing bacteria (SRB) suspension for 6 days, the cell adhesion density on LIS decreases by one order of magnitude compared with that on bare SS, thereby showing high bio-adhesion inhibition capability. The decrement of bacteria adhesion steadily decreases the MIC to SS. After exposure to SRB suspension for 10 days, the corrosion current density of LIS SS is only 1.06 × 10−8 A/cm2, which is lower than that of SHP coating under the same immersion periods. Therefore, the bio-inspired LIS for SS is a promising way to inhibit bioadhesion and biocorrosion in seawater environment.
Domaine de référence : Biocorrosion , Antifouling
Auteur Ouyang Yibo, Zhao Jin, Qiu Ri, Hu Shugang, Niu Haili, Zhang Yan, Chen Ming
Année de parution : 2019.
Mots-clés : Bioinspired, Liquid infused surface, Microbiologically influenced corrosion, Nepenthes pitcher, Stainless steel, Superhydrophobicity.
Type de document : Article de revue.
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Plus de références Biocorrosion


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Small-Scale Effects of Offshore Wind-Turbine Foundations on Macrobenthic Assemblages in Pinghai Bay, China

Résumé : In recent years, offshore wind farms in China have developed rapidly, especially in SE coastal regions. The construction of wind-turbine foundations (WTFs) introduces new artificial structures into coastal ecosystems, influencing the surrounding macrobenthos. Small-scale effects on macrobenthic assemblages around a high-rise cap pile WTF in Pinghai Bay, China, were investigated in November 2017 and May 2018, along SW and SE gradients. The macrobenthic abundance increased from 220 ± 92 individuals (ind) m–2 at 200 m to 547 ± 103 ind m–2 at 25 m from the foundation, and the species number increased from 8 ± 3 at 200 m to 16 ± 6 per sample at 25 m from the foundation, whereas the biomass decreased from 17.2 ± 2 g m–2 at 200 m to 3.1 ± 1.4 g m–2 at 25 m from the foundation. The macrobenthic abundance increased by 94.75% compared with that before the WTF construction. Abundance significantly increased from 179 ± 115 to 463 ± 255 ind m–2 for Annelida, from 62 ± 56 to 99 ± 77 ind m–2 for Arthropoda, and from 4 ± 3 to 22 ± 25 ind m–2 for Echinodermata. However, the abundance of Mollusca decreased from 65 ± 100 to 14 ± 22 ind m–2. Thus, it is likely that most macrobenthos were able to recover quickly after the deployment of WTF, whereas more time might be needed for Mollusca to recover. There was also an obvious shift in species dominance, with Annelida becoming the dominant group (73.28–77.78%) in the macrobenthic community.
Domaine de référence : Antifouling
Auteur Lu Zhiqiang, Zhan Xiaofang, Guo Yuqing, Ma Li
Année de parution : 2019.
Type de document : Article de revue.
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A comprehensive review on recent advances in superhydrophobic surfaces and their applications for drag reduction

Résumé : Nowadays, superhydrophobic surfaces have attracted a lot of interest because of the wide range of applications in industries. These surfaces can significantly reduce the drag force due to the formation of air gaps between the substrate and liquid interface. The present review mainly focuses on the very recent progresses in the drag reduction studies using superhydrophobic surfaces. Also, a brief discussion about the mathematical modeling and the theories of superhydrophobic surfaces, natural water repellent surfaces, various fabrication techniques with advantages and disadvantages of each method and different properties of the fabricated surfaces in industrial applications is presented. Finally, the limitations of using such surfaces in industrial applications, which deals with harsh and destructive environment conditions, are addressed and further research topics and future outlooks to improve the durability of the superhydrophobic surfaces are discussed.
Domaine de référence : Antifouling
Auteur Liravi Mohammad, Pakzad Hossein, Moosavi Ali, Nouri-Borujerdi Ali
Année de parution : 2020.
Mots-clés : Coatings, Contact angle, Drag reduction, Lotus effect, Superhydrophobic surface.
Type de document : Article de revue.
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Optimizing image-based protocol to monitor macroepibenthic communities colonizing artificial structures

Résumé : Underwater imagery is increasingly used as an effective and repeatable method to monitor benthic ecosystems. Nevertheless, extracting ecologically relevant information from a large amount of raw images remains a time-consuming and somewhat laborious challenge. Thus, underwater imagery processing needs to strike a compromise between time-efficient image annotation and accuracy in quantifying benthic community composition. Designing and implementing robust image sampling and image annotation protocols are therefore critical to rationally address these trade-offs between ecological accuracy and processing time. The aim of this study was to develop and to optimize a reliable image scoring strategy based on the point count method using imagery data acquired on tide-swept macroepibenthic communities. Using a stepwise approach, we define an underwater imagery processing protocol that is effective in terms of (i) time allocated to overall image, (ii) reaching a satisfactory accuracy to estimate the occurrence of dominant benthic taxa, and (iii) adopting a sufficient taxonomic resolution to describe changes in community composition. We believe that our method is well adapted to investigate the composition of epibenthic communities on artificial reefs and can be useful in surveying colonization of other human structures (wind turbine foundations, pipelines, etc.) in coastal areas. Our strategy meets the increasing demand for inexpensive and time-effective tools for monitoring changes in benthic communities in a context of increasing coastal artificialization pressures.
Domaine de référence : Antifouling
Auteur Taormina Bastien, Marzloff Martin P., Desroy Nicolas, Caisey Xavier, Dugornay Olivier, Metral Thiesse Emmanuelle, Tancray Aurélien, Carlier Antoine
Année de parution : 2020.
Type de document : Article de revue.
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Marine fouling communities from artificial and natural habitats : comparison of resistance to chemical and physical disturbances

Résumé : Assessing the resistance of fouling communities to anthropogenic disturbances is an important goal for the development of effective management and control strategies. In this context, we conducted a manipulative experiment on natural and artificial habitats to examine fouling communities that developed outside and inside a marina on Madeira Island (NE Atlantic Ocean) following the application of two types of stressors frequently observed in coastal habitats, namely chemical and physical disturbances. The tested fouling communities, dominated by native and nonindigenous species respectively, were in general strongly affected by the chemical but not by the physical disturbance applied, and a higher resistance to disturbance was observed in the communities outside the marina. This suggests higher capacities for communities richer in native species to tolerate anthropogenic disturbances, while non-indigenous species did not play a key role. Further research can assess the resilience of natural and artificial fouling communities when exposed to disturbances.
Domaine de référence : Antifouling
Auteur Ferrario Jasmine, Gestoso Ignacio, Ramalhosa Patrício, Cacabelos Eva, Duarte Bernardo, Caçador Isabel, Canning-Clode João
Année de parution : 2019.
Type de document : Article de revue.
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Ferrario et al. - 2020 - Marine fouling communities from artificial and nat.pdf

Domaine de référence : Antifouling
Année de parution : 0.
Type de document : Pièce jointe.
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Laser Induced Breakdown Spectroscopy for Marine Biofouling Analysis

Résumé : In the proposed study, Laser Induced Breakdown Spectroscopy (LIBS) has been employed for the analysis of marine biofouling samples. Nanosecond Nd3+:YAG laser pulses of wavelength 1064 nm, with pulse energy of about 42 mJ were used. The main elements detected were Na, Ca, K, Mg, Al, Fe etc.. This study is a preliminary attempt to quantify the elements of biofouling in its natural state. The database created from this study would help in formulation of new anti-fouling coatings.
Domaine de référence : Antifouling
Auteur Thomas Della, Surendran S, Vasa Nilesh J
Année de parution : 2019.
Type de document : Article de revue.
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Ultrasonic control of marine fouling

Résumé : The natural phenomenon of biofouling has brought about many undesirable consequences to the maritime industry. In the prevention of biofouling, anti-fouling methods have been highly sought after and anti-fouling coatings containing TBT compounds took precedence and was the most commonly utilised form of anti-fouling. However, TBT compounds inflicts catastrophic effects to the marine environment which brought about controversial attention to the IMO and eventually a worldwide ban on its usage was promulgated. The worldwide ban on the utilisation of TBT containing anti-fouling coatings has hence brought about increased demands to an alternative anti-fouling method, preferably a method which is friendly to the marine environment. In the exploration of an environmentally-benign anti-fouling method, the acoustic method which utilises ultrasonic waves exhibits potential in the prevention of biofouling. The continuation of the project seeks to replicate the application of Ultrasonic Guided Waves (UGW) at 100kHz in the shear horizontal mode into a surface of larger dimensions to evaluate on its effectiveness. The conduct of the experiment was held at a shipyard where conditions were experienced by vessels. The conduct of the experiment was presented with contradicting results compared to the previously acquired positive results. Although the results obtained in this experiment did not meet the expectations of the hypothesis, some concerns were highlighted in the recommendations in hope for positive results in the future.
Domaine de référence : Antifouling
Auteur Ng Kian Beng
Année de parution : 2019.
Type de document : Article de revue.
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The impact of hydrodynamic shear force on adhesion morphology and biofilm conformation of Bacillus sp.

Résumé : Biofilm formation is crucial for subsequent biofouling. Various factors can affect the biofilm formation. Here we report the influence of hydrodynamic shear force on adhesion morphology and biofilm conformation of Bacillus sp. on stainless steel by a flow cell system. Static, laminar and turbulent conditions were selected for this study. The applicability of this flow cell was evaluated by computational fluid dynamics (CFD). Stable wall shear stresses were successfully obtained. The results showed that the spatial distribution of bacteria changed from single-cell to cluster under the effect of shear force and the higher shear force created smoother and denser clusters. The different morphology of clusters under different flow conditions was mainly due to the increased nutrient supply to the clusters with the increase of flow velocity. Under the effect of shear force, Bacillus sp. could change the shape and increase the production of extracellular polymeric substance which could reduce the effect of shear force and enhance the connection and adhesion, respectively. Under low shear force, biofilm preferred to form irregular and complicated structure which could lead to the formation of tower like biofilm and inhibit the external mass transfer. The results could shed some light on biofilm control strategies.
Domaine de référence : Antifouling
Auteur Chang Jiangfan, He Xiaoyan, Bai Xiuqin, Yuan Chengqing
Année de parution : 2020.
Mots-clés : Biofilm, Conformation, Hydrodynamic shear force, Morphology.
Type de document : Article de revue.
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Decreasing of Escherichia coli in saline environment using system impressed current anti fouling (ICAF)

Résumé : Corrosion in marine buildings both onshore and offshore can cause many losses. One of the main causes of biocorrosion is biofouling. Biofouling itself is an accumulation of undesirable biological matter on the surface of material and is caused either by macroorganism such as bacteria, fungi, microalgae, and protozoa. Escherichia coli could affect the rate of metal corrosion due to this bacteria can produce polymer during biofilm formation. The Impressed Current Anti Fouling (ICAF) method is one way to prevent the biofouling. The aim of research was to determine reduction of Escherichia coli population using simple ICAF system. The simple ICAF reactor was operated with variation of electric current (0.1, 0.3 and 0.5 A) and duration time (5, 7 and 10 min). Steel of AH36 has role as an activated cathode, meanwhile pure copper (Cu) was as an anode. Simple ICAF system was arranged with plastic containers that filled with Escherichia coli. The population of Escherichia coli was determined using Colony Forming Unit (CFU) method. The concentration of ion Cu was analyzed using Atomic Absorption Spectrophotometer.The other parameter that was observated was the pH, salinity and temperature during operation of simple ICAFsystem. Based on results, the time duration was longer and variation of electrical current was higher at ICAF system operation so that the reduction of Escherichia coli increased. The population Escherichia coli reduction reached over 90% for 10 min at all variation of electrical current. The range of Cu concentrations were 1.2 mg/L – 28.8 mg/L. In conclusion, ion Cu that was produced during operation of simple ICAF system can reduce Escherichia coli population.
Domaine de référence : Antifouling
Auteur Pratikno Herman, Titah Harmin Sulistiyaning, Handayanu
Année de parution : 2019.
Type de document : Article de colloque.
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Preparation and synergistic antifouling effect of self-renewable coatings containing quaternary ammonium-functionalized SiO2 nanoparticles

Résumé : Confronting the complexity of marine biofouling, no single ecofriendly technology has been reported for efficient anti-biofouling. Combination of multiple antifouling factors should be one of the strategies for strengthening the anti-biofouling performance. Here we synthesized quaternary ammonium modified SiO2 nanoparticles (QAS-SiO2) and incorporated them into self-polishing polymer (SP) to get the coatings combining self-renewal ability, micro-nano structured topography, and bactericidal function. The coatings acquired underwater superoleophobic surface after immersion in artificial seawater due to their micro-nano structured surface together with the hydrolyzed SP. In comparison with unmodified SiO2, QAS-SiO2 had better compatibility with SP and caused less increment of self-polishing rate. Synergistic antifouling effect was interestingly observed between self-renewal ability and bactericidal function in both the laboratory assay based on the adhesion of Shewanella loihicas and natural field trial. The micro-nano structured topography contributed to underwater superoleophobicity but did not exhibit its impact on antifouling performance. QAS-SiO2 can also slightly inhibit the adhesion of diatoms and reduce the settlement of plantigrades of the mussel. In addition, we also demonstrated the coatings with lower quantity of biofilm exhibited less settlement of plantigrades of mussel.
Domaine de référence : Antifouling
Auteur Wang Donghui, Xu Jiakang, Yang Jinlong, Zhou Shuxue
Année de parution : 2020.
Mots-clés : Marine antifouling coatings, Quaternary ammonium, Self-renewable, SiO nanoparticles, Synergistic anti-biofouling.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

A new biomimetic antifouling method based on water jet for marine structures

Résumé : Marine biofouling is a serious environmental problem, while traditional chemical antifouling is less environmentally friendly. Biomimetic antifouling is able to overcome this issue by restraining the growth of biofouling at the very beginning, while the current research interest in this field focuses on the dynamic antifouling layers. In order to construct a flowing layer on the surfaces of marine structures such as a ship hull, this study proposes a new biomimetic antifouling method based on the water jet. This new method is inspired by the antifouling mechanism of the kelp and attempts to generate a flowing jet layer on the surface of the marine structure by spraying the water outward. The fouling organism cannot find enough attachment points on the surface of the marine structure because the flow force is greater than adhesion. In order to optimize the design of the water jet, attachment point theory was used to analyze the effect of jet velocity on the flow force, and numerical simulation was conducted to investigate the distribution of the water jet. Based on the theoretical analysis results, experimental tests were carried out to evaluate the performance of the proposed antifouling method. The results demonstrated that the adhesion amount of Phaeodactylum tricornutum can be effectively reduced. The proposed method is able to prevent the attachment of unicellular fouling organisms, thereby hindering the entire fouling process.
Domaine de référence : Antifouling
Auteur Liu Guijie, Yuan Zichao, Incecik Atilla, Leng Dingxin, Wang Shuai, Li Zhixiong
Année de parution : 2019.
Mots-clés : biomimetic antifouling, dynamic antifouling layer, Marine structures, water jet.
Type de document : Article de revue.
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Vapor-Deposited Biointerfaces and Bacteria : An Evolving Conversation

Résumé : At the biointerface where materials and microorganisms meet, the organic and synthetic worlds merge into a new science that directs the design and safe use of synthetic materials for biological applications. Vapor deposition techniques provide an effective way to control the material properties of these biointerfaces with molecular-level precision that is important for biomaterials to interface with bacteria. In recent years, biointerface research that focuses on bacteria-surface interactions has been primarily driven by the goals of killing bacteria (antimicrobial) and fouling prevention (antifouling). Nevertheless, vapor deposition techniques have the potential to create biointerfaces with features that can manipulate and dictate the behavior of bacteria rather than killing or deterring them. In this review, we focus on recent advances in antimicrobial and antifouling biointerfaces produced through vapor deposition and provide an outlook on opportunities to capitalize on the features of these techniques to find unexplored connections between surface features and microbial behavior.
Domaine de référence : Antifouling
Auteur Donadt Trevor B, Yang Rong
Année de parution : 2019.
Type de document : Article de revue.
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Modification of nano-hybrid silicon acrylic resin with anticorrosion and hydrophobic properties

Résumé : Silicone-acrylic resin (SAR) was prepared from acrylic monomers and silicone prepolymer by the free radical solution polymerization, and then mixed TiO2 and SiO2 nanoparticles modified by KH570 were added to prepare nanocomposite coating. Thermogravimetric analysis and contact angle measurements showed that the acrylic resin modified by silicone prepolymer exhibited an improved thermostability and a better hydrophobicity compared with the unmodified sample. The adding of nanoparticles further increased the hydrophobicity. The contact angle of modified silicone-acrylic resin with mixed TiO2 and SiO2 nanoparticles of 3 wt% is the highest, 108.4°. The UV resistance and weather resistance of the modified silicone-acrylic resin are significantly improved. It was also found through electrochemical impedance spectroscopy that the corrosion resistance was significantly improved by the addition of mixed TiO2 and SiO2 nanoparticles. Modified silicone-acrylic resin with mixed TiO2 and SiO2 nanoparticles of 3 wt% and 5 wt% coating system maintains an excellent anticorrosion performance (coating resistance Rc of more than 109 Ω cm2) even at 3.5% NaCl electrolyte medium till to 1800 h.
Domaine de référence : Antifouling
Auteur Jiang Weibin, Jin Xiongfei, Li Huan, Zhang Shiyu, Zhou Tao, Xie Huasheng
Année de parution : 2019.
Mots-clés : Acrylic resin, Anticorrosion, Coating, Nanocomposite, Silicon.
Type de document : Article de revue.
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Biofouling Inhibition with Grafted Econea Biocide : Toward a Nonreleasing Eco-Friendly Multiresistant Antifouling Coating

Résumé : The most effective strategies to control biofouling release toxic and persistent agents into the aquatic environment causing environmental concerns and leading to the implementation of more strict international legislation. This work presents recent progress on an innovative eco-friendly antifouling approach based on the isocyanate-functionalized Econea biocide allowing its chemical fixation in polymeric frameworks, namely, in a foul-release marine coating. The antifouling potential of the generated nonbiocide release coatings for both antimicrobial and long-term marine anti-biofouling applications is reported here for the first time. Inhibition growth effects against Methicillin-resistant Staphylococcus aureus bacterium obtained for Econea-based coatings reveal a decrease in the number of colony forming units (CFUs) up to 5 orders of magnitude in 6 h of exposure when compared to the free bacteria. The growth and the viability profiles (CFU/mL) revealed also bacteriostatic effects. The nonbiocide release coatings were able to minimize considerably the biocide release, becoming 10-fold lower than in a conventional releasing system and providing long-lasting antifouling effects, more than two years, under real seawater conditions. Both antifouling effects follow a nonbiocide release strategy leading to a minimization of the environmental impact of the biocidal coatings and the selective pressure on the microorganisms that evolve treatment resistance.
Domaine de référence : Antifouling
Auteur Ferreira Olga, Rijo Patrícia, Gomes João F., Santos Ricardo, Monteiro Silvia, Vilas-Boas Cátia, Correia-da-Silva Marta, Almada Stephanie, Alves Luis G., Bordado João C., Silva Elisabete R.
Année de parution : 2019.
Type de document : Article de revue.
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Bacterial benthic community composition in the Baltic Sea in selected chemical and conventional weapons dump sites affected by munition corrosion

Résumé : Microflora of marine waters and sediments play a significant role not only in the course of natural changes and circulation of elements in this environment, but can also be a decisive factor during erosion processes of various submerged objects or structures such as wrecks, sunken objects, pipelines, etc. The bacteria which have a significant influence on corrosion processes include aerobic and anaerobic sulfur bacteria as well as iron bacteria. Particular importance is attributed to sulfide reducing bacteria (SRB) which occur in waters, bottom sediments, creating biofilms on metal surface, and may start a process known as microbial induced corrosion (MIC). The occurrence of these bacteria and their populations indicates potential and intensification of corrosion processes. The aim of the study was to determine the number of microorganisms from various groups in the Baltic Sea sediments, especially those that are active in biological corrosion processes. This data can be used for a study comprehensive of corrosive processes in the marine environment, and as a result, to carry out a real assessment of the risks arising from the release of toxic substances into the environment from conventional and chemical weapons lying on the bottom caused by progressing corrosive processes, including biological corrosion. The article presents the results of research on the presence and accounts of microorganisms in bottom sediment samples taken from the dump sites of chemical and conventional ammunition in the Baltic Sea. Particular attention was paid to halophilic and halotolerant bacteria due to their significant contribution to both corrosion and decomposition processes of CWA and explosives, particularly in the saltwater environment. There were high and quite similar numbers of mesophilic, psychrophilic and halophilic bacteria in the studied samples, while significantly smaller numbers of anaerobic bacteria. The amount of mesophilic bacteria ranges from 6.42*103 to 2.85*107, on average 4.5*106 in 1 g DM, psychrofilnych od psychrophilic from 5.73*103 in1g DM to 4.11*107 in 1 g DM, on average 6.44*106 in 1 g DM, natomiast dla halofilnych od whereas for halophylic from 4.09*102 to 5.60*107, on average 5.83*106 in1g DM. The numbers of fungi were at a much lower level i zawierały w przedziałach od and ranged from 4.65*101 to 8.08*102, on average 2.63*102 in 1 g DM. mesophilic fungi and from 0 to 1.60*103, on average 3.58*102 in 1 g DM for psychrophilic fungi. The presence of sulfide reducing bacteria (SRB) was also detected in large populations, especially when they were isolated by means of the medium prepared with seawater (from 9.72 to 5.36*102, on average 2.52*102 in 1 g DM), which indicates their adaptation to the saline environment and promotes of biological anaerobic processes, including corrosive processes. No significant amounts of iron bacteria were found, probably due to the small amount of oxygen in the sampling area. The small number of iron bacteria indicates that primarily anaerobic sulfide reducing bacteria (SRB) have the major part in the microbial corrosion phenomena.
Domaine de référence : Antifouling
Auteur Cybulska Krystyna, Łońska Edyta, Fabisiak Jacek
Année de parution : 2019.
Mots-clés : Bacteria, Baltic Sea, Biological corrosion, Chemical weapons, Conventional weapons.
Type de document : Article de revue.
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Quorum Sensing and Its Applications in Diverse Fields of Significance

Résumé : Several unicellular microorganisms use small signalling molecules to find out their local concentration. The processes involved in the production andrecognition of these signals are generally known as quorum sensing (QS). Unicellular microorganisms to manage their activities use this kind of cellto- cell communication, which allows them to work as multi-cellular systems. Newly, several groups have confirmed artificial intra species and inter-species communication through synthetic circuits, which incorporate components of bacterial QS systems
Domaine de référence : Antifouling
Auteur Aziz Malik Asif, Lone Shazia, Ah. Malik Mushtaq, Dar Zaffar Mahdi, Masood Amjad, Shafi Saima, Sidique Showkat
Année de parution : 2019.
Type de document : Article de revue.
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Non-antibiotic Antimicrobial Agents to Combat Biofilm-forming Bacteria

Résumé : Biofilms can be produced by multiple species or by a single strain of bacteria. The biofilm state enhances the resistance of the resident microorganisms to antimicrobial agents by producing extracellular polymeric substances. Typically, antibiotics are used to stop the growth of bacteria, but emerging resistance has limited their effectiveness. Bacteria in biofilms are less susceptible to antibiotics compared with their free-floating state, as biofilms impair antibiotic penetration. To obviate this challenge, non-antibiotic antimicrobial agents are needed. This review describes two classes of these agents, namely antimicrobial nanoparticles and antimicrobial peptides. Applications of these antimicrobials in the food industry and medical applications are discussed, and the directions for future research are highlighted.
Domaine de référence : Antifouling
Auteur Cao Yuxue, Naseri Mahdi, He Yan, Xu Chun, Walsh Laurence J., Ziora Zyta M.
Année de parution : 2019.
Mots-clés : Antimicrobial, Bacteria, Biofilm, Non-antibiotic.
Type de document : Article de revue.
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Strong adhesion of poly(vinyl alcohol)–glycerol hydrogels onto metal substrates for marine antifouling applications

Résumé : Hydrogels can be used as an alternative coating material for ships against marine biofouling. However, the adhesion of wet and soft hydrogels onto solid metals remains a challenging problem. Here we report the adhesion of a typical hydrogel material, poly(vinyl alcohol) (PVA)–glycerol hydrogel, onto stainless steel substrates and the antifouling potency of the adhered PVA–glycerol hydrogels. Poly(allylamine hydrochloride) (PAH) hydrogel and ethyl α-cyanoacrylate (ECA) are used as the binders, and they are found to be able to firmly bond the PVA–glycerol hydrogels onto the stainless steel substrates. The PAH hydrogel does not affect the mechanical properties of the PVA–glycerol hydrogel during use, but it tends to lose the adhesive ability in a dehydrating environment. In contrast, the ECA adhesive can maintain strong bonding between PVA–glycerol hydrogels and substrates upon several water losing/water absorbing cycles, despite some negative effects on the strength of the PVA–glycerol hydrogel. Biological experiments show that the PVA–glycerol hydrogel has a strong settlement-inhibiting effect on the barnacle Balanus albicostatus, suggesting that combining the PVA–glycerol hydrogel with ECA adhesive may have promising applications in marine antifouling.
Domaine de référence : Antifouling
Auteur Zhu Heng-Wei, Zhang Jia-Nan, Su Pei, Liu Tianqi, He Changcheng, Feng Danqing, Wang Huiliang
Année de parution : 2019.
Type de document : Article de revue.
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Superhydrophobic Coatings for Corrosion and Tribology

Résumé : Superhydrophobic surfaces, with a water contact angle &gt;150°, have attracted both academic and industrial interest due to their wide range of applications, such as water proofing, anti-fogging, antifouling, anti-icing, fluidic drag reduction and anti-corrosion. Currently the majority of superhydrophobic coatings are created using organic chemicals with low surface energy. However, the lack of mechanical strength and heat resistance prevents the use of these coatings in harsh environments. Quality superhydrophobic coatings developed using inorganic materials are therefore highly sought after. Ceramics are of particular interest due to their high mechanical strength, heat and corrosion resistance. Such superhydrophobic coatings have recently been successfully fabricated using a variety of ceramics and different approaches, and have shown the improved wear and tribocorrosion resistance properties. This Special Issue will focus on the recent developments in the fabrication of superhydrophobic coatings and their robustness against corrosion and wear resistance, but the original work on other properties of superhydrophobic coatings are also welcome. In particular, the topics of interest include, but are not limited to:- Robust superhydrophobic coatings;- Coatings with super-wettability in multifunctional applications;- Wetting effects on corrosion and tribology;- Hierarchical Coating for wetting and modelling
Domaine de référence : Antifouling
Auteur Wang Shuncai, Zhao Guochen
Année de parution : 2019.
Mots-clés : Science / Chemistry / General.
Type de document : Livre.
Source : MDPI
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Enhanced antifouling property of Fluorocarbon resin coating (PEVE) by the modification of g-C3N4/Ag2WO4 composite Step-Scheme photocatalyst

Résumé : In the complex ocean environment, the attachment of marine creatures to the hull of a ship and to marine infrastructure has been a highly important problem. Ag2WO4 is an effective photocatalytic material and bacteriostatic agent that has seen only limited application due to its lack of optical stability and low quantum yield, necessitating the further development of this material. In this work, a fluorocarbon resin coating (PEVE) is used as the matrix and is modified by g-C3N4/Ag2WO4 composite catalysts. Experimental results show that the modified coating exhibits excellent antibacterial ability and cycle stability under visible light. The Step-scheme heterojunction between g-C3N4 and Ag2WO4 inhibited the recombination of the photogenerated electron-hole pairs in the photocatalyst and enhanced the photocatalytic activity and stability. The presence of g-C3N4 contributes to the formation of the beta (β)-Ag2WO4 metastable phase, and the mechanism contributing to the phase transformation was examined by first-principle calculations for the first time.
Domaine de référence : Antifouling
Auteur Zhu Zhenyu, Zhou Feng, Zhan Su
Année de parution : 2019.
Mots-clés : AgWO, Antifouling coating, g-CN, Metastable phase, PEVE.
Type de document : Article de revue.
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Preparation of Hydrophobic Epoxy Polydimethylsiloxane Graphene oxide Nanocomposite Coatings for Antifouling Application

Résumé : The epoxy-polydimethylsiloxane-graphene oxide (EPG) nanocomposite coatings have been successfully developed by loading different wt.% of graphene oxide nanosheets (GNs) into epoxy-hydroxy-terminated-polydimethylsiloxane (EP-hPD) matrix via facile in-situ preparation technique. The inclusion of GNs into EPN led to increase in modulus of elasticity and tensile strength upto 1570.46 MPa and 31.54 MPa, respectively in case of 1 wt.% loading of GNs in EP-hPD matrix. Also, a rise in water contact angle from 90.1° to 115.2°, 104.5° and 101.7° was discerned at 1, 3 and 5 wt.% loading of GNs. Taber abrasion results demonstrated a decrement in abrasion loss by 33.3% at 1 wt.% loading of GNs in comparison to the unreinforced coating. An improvement in glass transition temperature (Tg) was remarked from 63.5°C for neat sample to 77.6°C, 76.3°C and 71.6°C for 1, 3 and 5 wt.% EPG nanocomposite. An inevitable enhancement in properties of nanocomposite at has been affirmed due to the synergistic effect of GNs dispersed within EP-hPD blend matrix. The prominent findings of the work include minimum corrosion rate of 0.73 × 10-2 mm/year and upgradation in antifouling performance of the nanocomposite coating in comparison to the neat coating.
Domaine de référence : Antifouling
Auteur Verma Shatakshi, Mohanty Smita, Nayak Sanjay K.
Année de parution : 2019.
Type de document : Article de revue.
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Superhydrophobic copper in biological liquids : Antibacterial activity and microbiologically induced or inhibited corrosion

Résumé : The bactericidal activity of copper and copper alloys is well appreciated and was already exploited in medical practice in 19th century. However, despite of being an essential nutrient required by organisms to perform life functions, excess copper is extremely toxic and detrimental to health. Recent studies have shown that superhydrophobic surfaces have a significant antibacterial potential for reduction of nosocomial infections. At the same time, the prolonged contact with biological liquids may cause a degradation of the superhydrophobic copper surface and corrosion with increasing egress of toxic copper ions. These aspects are poorly studied so far. In this paper, we analyze the evolution of the properties of both the superhydrophobic copper surface and the suspension of Escherichia coli bacteria during their prolonged contact and study the impact of such contact on the bactericidal activity of the surface. It is shown that by controlling the corrosion resistance and the wettability of the superhydrophobic copper substrate, it becomes possible to sustain the bactericidal action of copper substrates for a long time, simultaneously avoiding the excessive corrosive degradation and release of copper ions in the environment.
Domaine de référence : Antifouling
Auteur Emelyanenko Alexandre M., Pytskii Ivan S., Kaminsky Valery V., Chulkova Elizaveta V., Domantovsky Alexander G., Emelyanenko Kirill A., Sobolev Vladimir D., Aleshkin Andrey V., Boinovich Ludmila B.
Année de parution : 2020.
Mots-clés : Anti-bacterial surfaces, Biocorrosion, Biofilm formation, Corrosion inhibition, Microbiologically induced corrosion, Superhydrophobic surfaces.
Type de document : Article de revue.
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Diversity of attached marine life in different types of artificial timber reefs

Résumé : Artificial reefs (ARs) have been implemented as a tool to increase fish catch by gathering fish and creating new habitat. In Japan, fisheries production has been decreasing in the last several decades. Research on ARs to date has mainly focused on fish biomass and community structure. The present study describes the community structure of marine organisms attached to the ARs deployed in Mitsu Bay, Hiroshima, Japan. We compare those communities on three types of ARs, which are made of timbers (ATRs), ATRs with oyster shells (ATRsOS) and ATRs with leaves and branches (ATRsLB). Attached organisms were collected seasonally from 2016 to 2018. Overall, 272 taxa were identified from two deployment sites. Arthropods were the dominant group identified, followed by molluscs and annelids. Seasonal variation of individuals collected was observed, with numbers being high in summer and low in winter. The number of individuals was high in the first year after deployment of ATRs, decreasing in the second year and beyond, suggesting the animal community may have matured by balancing the growth and feeding by fish. All three types of ATRs were commonly large in individual number and small in species number, characterized by a low diversity index. The highest individual number and highest species number were observed in ATRsLB and ATRsOS, respectively. More specifically, the diversity index for simple ATRs was lower than those for ATRsOS and ATRsLB. This result suggests that ATRs with additional materials can provide a wide range of feed animals which may attract more fish. The deployment of ATRs made of materials like timbers and oyster shells is also good practice for promoting a recycling-oriented society.
Domaine de référence : Antifouling
Auteur Alam J F, Yamamoto T, Umino T, Nakahara S, Hiraoka K
Année de parution : 2019.
Type de document : Article de revue.
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The impact of biofouling on marine environment : a qualitative review of the current antifouling technologies

Résumé : This dissertation is a qualitative review of the harmful effects of biofouling on both the environment and the ship performance, and the technologies that have been used throughout history to prevent its adherence to the hulls of ships. A brief review is carried out to present the historical approach to the evolution of antifouling systems and to identify the impacts of bio-fouling on the marine environment. A focused examination of the harmful effects of the transfer of invasive aquatic species (IAS) will be detailed. In addition, it will be explained how biofouling seriously affects the efficiency of the ship due to the increase in the roughness of the hull, among other factors. Problems related to the toxicity of the first antifouling paints that used compounds such as TBT will be explained. As a response from the international community to this growing problem, legal instruments promoted by IMO and other specific regulations have been introduced in some of the most affected countries such as Australia, New Zealand and the United States, which will be mentioned in this work to clarify their capacity and limitations to address the problem from different aspects. Moreover, a description will be given to the most used and available antifouling systems in the market, differentiating them according to their mechanisms of action, depending on whether biocides are used or not. This review will also include another significant point, such as in water hull cleaning, shore based antifouling paints removal. Finally, it will be, and according to the information as mentioned earlier through this dissertation to recommend which are the most appropriate antifouling systems, according to their efficiency and the environmental impacts, those might be produced to the aquatic system.
Domaine de référence : Antifouling
Auteur Alghamdi Sultan Ahmed, Cordova Rafael Alejandro Quijada
Année de parution : 2019.
Type de document : Article de revue.
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Antibacterial Activity of Sargassum polycystum and Ulva reticulata Methanol Extract Against Marine Fouling Bacteria

Résumé : Marine biofouling causes a lot of damage to the shipbuilding and aquaculture industry because of the increasing maintenance costs. The purposes of this research are to measure the effectiveness of seaweed to inhibit bacterial biofilms and determine their inhibitory concentrations. In this study, we used Sargassum polycystum and Ulva reticulata from Punaga coast, Takalar South Sulawesi, extracted with methanol to determine the potential of the extract as antifouling. There are 50 gr of Sargassum polycystum and Ulva reticulata was extracted with 300 ml of each solvent (1:6 w/v) for three times maceration The highest antibacterial activity assay using agar diffusion method was indicated by Sargassum polycystum extract with inhibition zone range from 13.35 to 15.80 mm. Antifouling activities from brown algae make them very promising as candidates for eco-friendly antifouling.
Domaine de référence : Antifouling
Auteur Wulandari Viki, Latama Gunarto, Zainuddin Elmi Nurhaidah
Année de parution : 2019.
Type de document : Article de revue.
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Seasonality combined with the orientation of surfaces influences the microbial community structure of biofilms in the deep Mediterranean Sea

Résumé : Attachment to surfaces represents an important life strategy for microbial communities as indicated by the rapid colonization of biotic and abiotic surfaces in marine waters. However, little attention has been paid to the development of biofilm-associated microbial communities and the environmental parameters influencing biofilm development in the deep sea. In this study, a deep-sea experimental setup was used to follow the development of the microbial community colonizing solid surfaces deployed at 4500 m depth at the deepest point of the Mediterranean Sea. The experiment was performed during summer (May to October 2007) and winter (October 2007–May 2008), each lasting for 155 d. The phylogenetic composition of the biofilm community was determined by tag sequencing of the 16S rRNA gene. We investigated whether the composition of the deep-sea microbial biofilms is influenced by seasonality. Based on tag sequencing, operational taxonomic units were identified and diversity indices calculated. Seasonality combined with the orientation of the solid surface on which the biofilms were growing was the main factor influencing the structure of the microbial community. The most abundant phyla of deep-sea biofilm communities attached to the solid surfaces were Gammaproteobacteria (range: 10.8%–92.6%), Alphaproteobacteria (range: 34.9%–92.6%) and Betaproteobacteria (range: 0.3%–2.1%), irrespective of the variables (surface, orientation, season). Flavobacteria and Epsilonbacteria show a clear preference with respect to the orientation of the deployed surfaces during the winter, however, they were essentially absent at the surfaces during the summer. Some bacterial classes such as Campylobacterales and Rhodobacterales showed distinct preferences for specific seasons or orientation of the substrate. Taken together, we conclude that even on deep-sea biofilms, there is to some extent seasonality detectable in the composition of the surface associated prokaryotic community, despite the fact that the deep-sea is, in terms of physico-chemical parameters, a fairly stable environment.
Domaine de référence : Antifouling
Auteur Bellou Nikoleta, Garcia Juan Antonio L., Colijn Franciscus, Herndl Gerhard J.
Année de parution : 2019.
Type de document : Article de revue.
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Finite Element Analysis of Underwater Ultrasonic Cleaning System Based on Ansys

Résumé : In this study, the finite element model of the ultrasonic cleaning system was established and the harmonic response analysis was carried out to obtain the vibration distribution of the ultrasonic cleaning floor and the sound pressure distribution in the water. Scanning electron microscopy was used to observe the adhesion of fouling organisms. The results show that the ultrasonic treatment mode has a significant effect on the microscopic fouling adsorption of PMMA surface. When the total time of the ultrasonic action is same, the shorter the ultrasonic interval time, the more significant the effect of ultrasonic decontamination.
Domaine de référence : Antifouling
Auteur Xu Haoran, Zhang Guohua, Wang Yanqing
Année de parution : 2019.
Type de document : Article de revue.
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Characterization and assessment of barnacle larval settlement-inducing activity of extracellular polymeric substances isolated from marine biofilm bacteria

Résumé : Extracellular polymeric substances (EPSs) are the hydrated gelatinous matrix produced by microorganisms for attachment in a biofilm environment. In this study, the compositional variation between EPSs of three marine biofilm bacteria (Pseudoalteromonas shioyasakiensis, Vibrio harveyi and Planomicrobium sp.) were analysed by GC-MS, 1H NMR, FT-IR and XRD and SEM. The ecological significance of exopolymers was assessed in vivo using marine model organism barnacle larvae for their settlement-inducing activity. Chemical analysis revealed the presence of glycan fucosylated oligosaccharides, tetraose, trisaccharides, iso-B-Pentasaccharides, sialyllactose, oligomannose, galacto-N-biose, difucosyl-para-lacto-N-neohexaose, 3′-sialyl N-acetyllactosamine and isoglobotriaose-β-N(Acetyl)-Propargyl in all extracted EPSs. Bioassay results indicated that treatment of the barnacle larvae with EPSs from three bacterial strains enhanced settlement on substrates. In conclusion, this study highlighted the role of water-soluble EPSs in the invertebrate larval settlement on artificial materials.
Domaine de référence : Antifouling
Auteur Siddik Aboobucker, Satheesh Sathianeson
Année de parution : 2019.
Type de document : Article de revue.
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Metagenomic resolution of functional diversity in copper surface-associated marine biofilms

Résumé : We used metagenomic sequencing combined with morphological and chemical analyses to investigate microbial taxa and functions related to copper-resistance and microbiologically influenced corrosion in mature copper-associated biofilms in coastal seawater for 44 months. Facultative anaerobic microbes such as Woeseia sp. were found to be the dominant groups on the copper surface. Genes related to stress response and possible heavy metal transport systems, especially RNA polymerase sigma factors (rpoE) and putative ATP-binding cassette (ABC) transport system permease protein (ABC.CD.P) were observed to be highly enriched in copper-associated biofilms, while genes encoding DNA-methyltransferase and RNA polymerase subunit were highly enriched in aluminum-associated biofilms and seawater planktonic cells, respectively. Moreover, copper-associated biofilms harbored abundant copper-resistance genes including cus, cop and pco, as well as abundant genes related to extracellular polymeric substances (EPS), indicating the presence of diverse copper-resistance patterns. The proportion of dsr in copper-associated biofilms, key genes related to sulfide production, was as low as that in aluminum biofilm and seawater, which ruled out the possibility of microbial sulfide-induced copper-corrosion under field conditions. These results may fill knowledge gaps about the in situ microbial functions of marine biofilms and their effects on toxic-metal corrosion.
Domaine de référence : Antifouling
Auteur Zhang Yimeng, Ma Yan, Zhang Ruiyong, Zhang Binbin, Zhai Xiaofan, Li Wangqiang, Xu Liting, Jiang Quantong, Duan Jizhou, Hou Baorong
Année de parution : 2019.
Mots-clés : biocorrosion, Biofilm, Biofouling, Copper-resistance, gene, marine, metal alloy.
Type de document : Article de revue.
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Macrobenthic fouling assemblages and NIS success in a Mediterranean port : The role of use destination

Résumé : Macrozoobenthic fouling assemblages were studied in the port area of Livorno, focusing on the occurrence of non-indigenous species (NIS). Sampling was carried out at ten sites characterised by different anthropic impacts related to their use destination. Among the 262 species identified, twenty-six were alien or cryptogenic, seventeen of which were new records for the study area, confirming the role of the port of Livorno as a hotspot of NIS introduction. Multivariate analyses highlighted a strong influence of the use destination on the diversity of macrozoobenthic communities. Even though the majority of transoceanic maritime traffic from and to Livorno pertains to the commercial harbour, the touristic harbour hosted the highest number of NIS, possibly because of secondary spread from other Mediterranean ports. The ALien Biotic IndEX (ALEX) identified all sites as high or good environmental status, but the large number of NIS detected suggests caution about their impact and further spread.
Domaine de référence : Antifouling
Auteur Tempesti J., Langeneck J., Maltagliati F., Castelli A.
Année de parution : 2019.
Mots-clés : Alien species, Hard bottoms, Human impact, Macrozoobenthos, Ports, Western Mediterranean.
Type de document : Article de revue.
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Cu Nanoparticle-Modified High-Density Polyethylene Monofilament and Its Antifouling Performance on Fishing Netting

Résumé : Cu nanoparticles (CuNPs) were modified by organic surfactant, then CuNP-modified high-density polyethylene (CuNP/HDPE) monofilaments were prepared by melt spinning. The effect of CuNP content on the morphology and properties of nanocomposite monofilaments was investigated. FT-IR and dynamic light scattering proved the successful surface modification for CuNP. Scanning electron microscope was used to observe the dispersed behavior of the CuNP. When the CuNP content was less than 1.0 wt%, the CuNPs were well dispersed in these nanocomposite monofilaments, and the increase of crystallization rate, the breaking strength, and knot strength were observed by differential scanning calorimeter and tensile test. Therefore, nanocomposite monofilaments showed comparable properties at low CuNP contents. With increasing CuNP content, the width of peak and for α-relaxation from dynamic mechanical analysis were increased, indicating more amorphous components near the crystalline regions. In addition, burst release of Cu ions in seawater was observed. The coupon tests demonstrated that CuNPs could significantly improve antibiofouling performance of CuNP/HDPE fishing netting. CuNP/HDPE fishing netting have a strong potential for using in marine antifouling mitigation.
Domaine de référence : Antifouling
Auteur Yu Wenwen, Liu Yongli, Wang Lei, Shi Jiangao
Année de parution : 2019.
Type de document : Page Web.
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Using hydrodynamic testing to assess the performance of fouling control coatings

Résumé : Static immersion studies are commonly used to assess the performance of fouling control coatings. While these tests provide valuable data, it is also of importance to understand the drag forces associated with the accrued fouling communities and the velocities required for fouling removal. Replicates of five commercially available coatings were deployed at two test sites located along the east coast of Florida. After four months of immersion, the coatings were subjected to known water velocities in a high-speed boat modified for hydrodynamic testing. Hard fouling adhesion measurements were taken to determine the attachment strength of organisms which remained on the panels. The type and extant of fouling varied based on static immersion location, this in turn influenced the fouling removal and the associated drag. While fouling removal was observed on all coatings, the percent removal was related to the coating type and the overall community structure. Those organisms which have a higher profile were easily removed. Lower form foulers, especially those with hard structures, had a minimum removal even at some of the top speeds. The data collected from this series of tests, enabled the fouling control and fouling release properties of each coating to be characterized.
Domaine de référence : Antifouling
Auteur Hunsucker Kelli Z., Gardner Harrison, Lieberman Kody, Swain Geoff
Année de parution : 2019.
Mots-clés : Antifouling, Biofouling, Fouling control coatings, Fouling release, Hydrodynamic test facility, Static immersion.
Type de document : Article de revue.
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The Mechanisms and Applications of Quorum Sensing (QS) and Quorum Quenching (QQ)

Résumé : Quorum sensing (QS) is a regulatory system that regulates the behavior of microbial populations by sensing the concentration of signal molecules that are spontaneously produced and released by bacteria. The strategy of blocking the QS system and inhibiting the production of virulence factors is termed as quorum quenching (QQ). This strategy attenuates virulence without killing the pathogens, thereby weakening the selective pressure on pathogens and postponing the evolution of QQ-mediated drug resistance. In recent years, there have been significant theoretical and practical developments in the field of QS and QQ. In particular, with the development and utilization of marine resources, more and more marine microbial species have been found to be regulated by these two mechanisms, further promoting the research progress of QS and QQ. In this review, we described the diversity of QS signals and QS-related regulatory systems, and then introduced mechanisms related to QS interference, with particular emphasis on the description of natural QQ enzymes and chemicals acting as QS inhibitors. Finally, the exploitation of quorum sensing quenchers and the practical application of QQ were introduced, while some QQ strategies were proposed as promising tools in different fields such as medicine, aquaculture, agriculture and biological pollution prevention areas.
Domaine de référence : Antifouling
Auteur Zhang Jingjing, Feng Tao, Wang Jiayi, Wang Yan, Zhang Xiao-Hua
Année de parution : 2019.
Mots-clés : antibiotic resistance, marine microorganisms, quorum quenching, quorum sensing.
Type de document : Article de revue.
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Antifouling coating material composition, antifouling coating film, substrate provided with antifouling coating film and production method therefor, and antifouling method

Résumé : An object of the present invention is to provide an antifouling coating composition capable of forming an antifouling coating film that retains a high antifouling performance for a prolonged period of time and has an excellent damage resistance. Another object of the present invention is to provide an antifouling coating film formed with the antifouling coating composition, a substrate with an antifouling coating film and a method for producing the same, and an antifouling method using the antifouling coating film. The antifouling coating composition of the present invention contains a hydrolyzable polymer (A) containing a metal ester group, zinc oxide (B), and medetomidine (C), and has a content of the zinc oxide (B) in a solid content of the antifouling composition of 27 to 60% by mass.
Domaine de référence : Antifouling
Auteur Niimoto Jyunji, Hayashi Yusuke, Masuda Satoshi, Tanaka Hideyuki
Année de parution : 2019.
Mots-clés : antifouling, antifouling coating, coating composition, coating film, group.
Type de document : Brevet.
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Novel molecular tools for optimizing surveillance of marine non-indigenous species

Résumé : Countries' economies, social values, ecosystem functioning and biodiversity are heavily impacted by marine non-indigenous species (NIS), mostly unintentionally transported via vessels' ballast water and hull biofouling. Costing billions of dollars annually, national and international conventions and legislations have been adopted to address this major threat but rely strongly on scientifically-validated data that can be applied to management plans. High-throughput molecular techniques using environmental DNA and RNA promise to be faster, more specific and have greater standardization for NIS monitoring than traditional surveillance programs based on morphology. However, remaining technical challenges may hinder reliable results. This thesis investigated novel molecular techniques for the use in marine NIS surveillance to implement an optimized molecular workflow into current NIS surveillance strategies. Three technical studies were undertaken, ranging from a broad metabarcoding screening of biofouling communities, to a close investigation of these communities for potential NIS, and finally to a species-specific targeted approach to better characterize erroneous detections. The differences among a range of biofouling communities were characterized using 16S rRNA, 18S rRNA and COI metabarcoding. Biofouling samples were taken from settlement plates simulating different ship hull conditions to attract NIS. The results were different patterns of change between bacterial and eukaryotic communities on artificial surfaces predicting their impacts on marine ecosystems. The same data were screened for NIS and bioinformatics pipelines were adjusted to explore different reference databases. The results were compared with the traditional morpho-taxonomic approach. The screening revealed considerable variation in potential NIS detections between 18S rRNA and COI metabarcoding, PR2, BOLD and NCBI databases, and when compared to the morpho-taxonomic approach. To address the issue of false positive and negative detections, target-optimized sampling was performed using species-specific droplet digital PCR. The focus on one NIS organism, Sabella spallanzanii, revealed detection errors through inhibition from the type of sampling matrix. Individually-designed sampling strategies are strongly advised. Overall, for molecular NIS surveillance, it is recommended to start with broad screening of multiple-marker metabarcoding data, filtered for potential NIS. Dependent on the risk assessment, further monitoring data and species-specific diagnostic tests may be needed to verify true detections. This thesis provides considerable base knowledge for managers and stakeholders to integrate molecular NIS surveillance and to evaluate the results for response plans.
Domaine de référence : Antifouling
Auteur Ammon Von, Edith Ulla
Année de parution : 2019.
Type de document : Thèse.
Source : ResearchSpace@Auckland
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Dual-functional anti-biofouling coatings with intrinsic self-healing ability

Résumé : The colonization of microbe on the material surface causes serious damage to the fields of biomedicine, water purification, and biosensors, and therefore versatile and biocompatible anti-biofouling coatings are highly demanded. Here, we fabricated a dual-functional (fouling-resist and antibacterial properties) anti-biofouling self-healing coating (DASC) with the triplex-crosslinked network (the covalent bonds, hydrogen bonds, and ionic interactions), which could be coated on 316L stainless steel substrate and demonstrated strong adhesive strength. The DASC-15 (the quaternary ammonium compounds accounts for 15 mol%) could inhibit the adhesion of biofouling due to its hydroxyethyl acrylate (HEA) and poly(ethylene glycol) methyl ether acrylate (PEGA480) units, and its anti-protein adhesion efficiency reached 90%. The presence of the quaternary ammonium compounds cations endowed the DASC-15 with excellent broad-spectrum antibacterial property, and the killing efficiency against Staphylococcus aureus and Escherichia coli was approximately 99.9%. Moreover, The DASC-15 could be repaired within 15 min under ambient condition after being scratched. The mechanical property restored to 92% of its original condition, which was derived from the destruction and recombination of the supramolecular non-covalent bonds. More prominently, larger scratches with the width of 200 μm could be repaired and the anti-biofouling property remained at the humidity of 90%. The coating is promising for biomaterial due to its strong metal adhesion, good biocompatibility, excellent anti-biofouling and outstanding self-healing properties.
Domaine de référence : Antifouling
Auteur Wang Cheng, Wang Ting, Hu PeiDong, Shen Tao, Xu JianHua, Ding ChenDi, Fu JiaJun
Année de parution : 2019.
Mots-clés : anti-fouling, antibacterial activity, self-healing, surface coating.
Type de document : Article de revue.
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Reduction of Vibrio alginolyticus population in system impressed current anti fouling (ICAF) for biofouling prevention

Résumé : Corrosion is a material damage caused by the influence of the surrounding environment. One of the causes of corrosion is bacteria or it was called as bio-corrosion or microbial influenced corrosion (MIC). The use of anti-corrosion systems such as Impressed Current Anti Fouling (ICAF) should continue to be developed so that a shortage of sacrificial anode system can be decreased. The concentration of Cu²⁺ that was released during operation of ICAF system can be used to reduce the population bacteria that caused bio-fouling. The purposes of the research were to determine the decreasing population of Vibrio alginolyticus using simple ICAF system and the concentration of Cu during simple ICAF process. Vibrio alginolyticus is a marine fouling bacterium that can cause bio-corrosion. The determination of population of Vibrio alginolyticus was conducted using pour plate count methode. The concentrations of Cu²⁺ were analyzed using Atomic Absorption Spectrophotometer. The other parameter that was observated was the pH during operation of simple ICAF system. The results showed that the value range of population reduction percentages were 87.3% - 99.4%. The measured concentration of Cu²⁺ metal ions during the operation of the simple ICAF system reached 4.3 mg/L to 18.3 mg/L. In conclusion, the simple ICAF system can be used to reduce population of Vibrio alginolyticus so that the bio-corrosion can be prevented.
Domaine de référence : Antifouling
Auteur Pratikno H., Titah Harmin, Handayanu Handayanu
Année de parution : 2019.
Type de document : Article de revue.
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Hydrophilic silicone coatings as fouling release : Simple synthesis, comparison to commercial, marine coatings and application on fresh water-cooled heat exchangers

Résumé : A synthesis route to hydrophilic, biocide-free fouling-release coatings by dispersing a polydimethyl siloxane (silicone, PDMS)-polyethylene glycol (PEG) copolymer in a PDMS coating is described. In comparison to known coatings including commercial fouling release for marine vessels, anti-fouling and fouling release performance was investigated by laboratory tests (contact angle, pseudo barnacle test and bacteria culture test applying Pseudomonas aeruginosa) and by application on fresh water-cooled surface condensers mimicking conditions of thermal power plants. A developmental silicone coating comprising PEG reduced fouling growth and adhesion in laboratory tests by more than a factor of ten compared to steel. In a freshwater exposure test, a comparative, commercial fouling release coating performed better than the developmental PEG-PDMS coating and is a promising candidate for applications on surface condensers of thermal power plants as it reduces fouling at a flow rate of just 1.6 m/s.
Domaine de référence : Antifouling
Auteur Holberg Stefan, Losada Ricardo, Blaikie Frances H., Hansen Helena H. W. B., Soreau Sylvie, Onderwater Rob C. A.
Année de parution : 2019.
Mots-clés : fouling, fouling release, heat exchanger, polyethylene glycol, power plant, silicone.
Type de document : Article de revue.
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Nanowall enclosed architecture infused by lubricant : A bio-inspired strategy for inhibiting bio-adhesion and bio-corrosion on stainless steel

Résumé : Microbiologically influenced corrosion (MIC) severely deteriorates metal material in seawater environment. Finding versatile coatings to inhibit bioadhesion and biocorrosion is a critical option to avoid degradation by microorganisms. Inspired by Nepenthes pitcher, this study prepares lubricant-infused surface (LIS) by using a three-step method: electrodeposition, vapor deposition, and oil infusion. First, Co(OH)2 is built on stainless steel (SS) via electrodeposition. The wrinkled nanowall circumvents the partition architecture, thus producing a highly porous structure. Second, through dodecanethiol modification, the combination of anchored hydrophobic moiety and porous structure creates a lotus-inspired superhydrophobic (SHP) surface. Third, oil infusion produces LIS. The independent partition architecture increases the anchoring effect to oil phase, thereby enhancing the stability. After immersion for 28 days in an abiotic seawater environment, the corrosion current density of SS covered by LIS SS is as low as 2.52 × 10−10 A/cm2, which is approximately fivefold lower than that of bare SS. After immersion in sulfate-reducing bacteria (SRB) suspension for 6 days, the cell adhesion density on LIS decreases by one order of magnitude compared with that on bare SS, thereby showing high bio-adhesion inhibition capability. The decrement of bacteria adhesion steadily decreases the MIC to SS. After exposure to SRB suspension for 10 days, the corrosion current density of LIS SS is only 1.06 × 10−8 A/cm2, which is lower than that of SHP coating under the same immersion periods. Therefore, the bio-inspired LIS for SS is a promising way to inhibit bioadhesion and biocorrosion in seawater environment.
Domaine de référence : Biocorrosion , Antifouling
Auteur Ouyang Yibo, Zhao Jin, Qiu Ri, Hu Shugang, Niu Haili, Zhang Yan, Chen Ming
Année de parution : 2019.
Mots-clés : Bioinspired, Liquid infused surface, Microbiologically influenced corrosion, Nepenthes pitcher, Stainless steel, Superhydrophobicity.
Type de document : Article de revue.
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Macrofouling Studies on Copper, Mild Steel and Stainless Steel Ss 316l at Surface and 6m Depth off Chennai Coast

Résumé : Macrofouling on Copper, Mild steel and Stainless steel 316L panels exposed to natural sea water conditions for six months was compared. Experimental coupons were deployed both at surface and at 6m depth using a test rig off Chennai. Barnacles and hydroids were the major foulants, followed by ascidians, oysters, green mussels and seaweeds which colonized initially for the first four months. The changes in fouling rates were correlated with environmental factors like temperature, dissolved oxygen, oxidation-reduction potential, salinity, etc. Percentage area fouled by macrofouling organisms showed a maximum coverage on the surface submerged mild steel and stainless steel 316L panels as the temperature and salinity favour the settlement of organisms, whereas, macrofouling was almost absent on copper panels. High percentage of barnacles, ascidians followed by polychaete settlement were observed on the stainless steel 316L and Mild steel panels.
Domaine de référence : Antifouling
Auteur Murthy P S, Vedaprakash L, Ratnam Krupa, Babu Mahesh, Venkatesan R, Kathiroli S
Année de parution : 2007.
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.