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Design optimization and control of a double stator permanent magnet generator for tidal energy applications

Résumé : This paper investigates a variable speed direct drive optimization and control for marine current energy application based on a Double Stator Permanent Magnet Generator (DSPMG). At first, turbine concepts, relative projects and usual conversion chains for tidal energy conversion are briefly presented. An original generator multi-objective optimal design method taking into account the tidal speed occurrence, control strategy and converter size to minimize the investment and maximize the annual energy output is developed. The conceptual advantages of the DSPMG are also used to show the possibility of uninterruptible operation under converter open phase faults. Simulation results are given and demonstrate the effectiveness of the optimization design and the proposed fault tolerant control.
Domaine de référence : EMR
Auteur Zhang Jian ZHANG, Moreau Luc, Houari Azeddine, Machmoum Mohamed
Année de parution : 2016.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Fault Detection of the Mooring system in Floating Offshore Wind Turbines based on the Wave-excited Linear Model

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

Coupled Motion Prediction of a Floating Tidal Current Power Station with Vertical Axis Twin-rotor Turbine

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

Array Arrangement on Vertical Axis Tidal Current Turbine Using Free Vortex Model

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

Evaluating Mooring Line Test Procedures through the Application of a Round Robin Test Approach

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

Reliability analysis of mooring lines for floating structures using ANN-BN inference

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

Long-term fatigue damage assessment for a floating offshore wind turbine under realistic environmental conditions

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

The international regulation for the protection of the environment in the development of marine renewable energy in the EU

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

Platform Stabilization of Floating Offshore Wind Turbines by Artificial Muscle based Active Mooring Line Force Control

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

Does wind speed effects performance and cost of energy ? A case study of wind farm

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

Coupled modeling and structural vibration control for floating offshore wind turbine

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

General Criteria for Optimal Site Selection for the Installation of Ocean Thermal Energy Conversion (OTEC) Plants in the Mexican Pacific

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

Research and Development Activities of Ocean Thermal Energy-Driven Development in Malaysia

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

Numerical Study on Initial Laying Process of Submarine Cables for Wave Energy Booster Station in Real Sea States

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

A Numerical Prediction on the Transient Response of a Spar-type Floating Offshore Wind Turbine in Freak Waves

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

Design and aerodynamic performance of new Floating H-Darrieus Vertical Axis Wind Turbines

Résumé : In the last decade, several countries started work on the development of Floating Vertical Axis Wind Turbines, which have significant advantages over Floating Horizontal Axis Wind Turbines. In the present work, we expose a brief history of the use of this type of wind turbines, and we contribute to understanding the existing technologies and we also propose a new design of Floating H-Darrieus Vertical Axis Wind Turbine with three stage rotors. This design solves the problem of starting a large turbine and facilitates maintenance by adopting three mechanisms Bearing Swivel Rollers at each stage. We use the Double Multiple StreamTube method for aerodynamic simulations. The numerical results of the aerodynamic performance analysis show that variable radius rotors maximize the power generated.
Domaine de référence : EMR
Auteur Dabachi Mohamed Amine, Rahmouni Abdellatif, Bouksour Otmane
Année de parution : 2020.
Mots-clés : DMST, F-VAWT, Offshore wind turbine, Three stage rotors, VAWT.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

A review on the technologies, design considerations and numerical models of tidal current turbines

Résumé : Tidal current turbine is one of the innovative and emerging technologies of marine renewable energies because it offers constant and predictable energy source that can be very beneficial, especially for commercial scale production of electrical power. Hydrofoils (HF) are essential elements of tidal current turbine (TCT) and should be properly designed as they play a vital role in improving the turbine output and providing adequate resistance to the blade structure. In connection with the hydrofoil designs, it is noteworthy that the primary objectives in their designs are to increase the coefficient of lift and to reduce the coefficients of drag and pitching moment, thus delaying the cavitation phenomenon. In this paper, the technology developments of the hydrofoil designs used in the horizontal axis TCT industry are reviewed, including the hydrodynamics design and the mechanical structure design. Besides, an up-to-date review and the newest achievements of marine TCT technologies with their developing histories are further explored. Included are also reviews on the numerical models used to assess the performance of TCT and optimization methods applied to design the hydrofoils. This in turn significantly contributes to a better knowledge on the recent designs of TCT hydrofoils for the researchers working in the marine turbine energy domain. Such information could also have important implications in the design of more sophisticated hydrofoils for the exploitation in diverse tidal current energy technologies for reaching a sustainable future.
Domaine de référence : EMR
Auteur Nachtane M., Tarfaoui M., Goda I., Rouway M.
Année de parution : 2020.
Mots-clés : Hydrofoil design, Marine renewable energies, Performance prediction, Tidal current turbine (TCT), Up-to-date review.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Hydrodynamic performance evaluation of a new hydrofoil design for marine current turbines

Résumé : Tidal energy has clear potential in producing large amounts of energy as the world’s capacity exceeds 120 GW. Despite being one of the oldest renewable energy sources exploited by man, the technology is still in its pre-commercialisation stage and so lags behind other renewable sources such as wind and geothermal energy in terms of development and energy produced. One of the emerging energy extraction technologies in the tidal energy field is the Horizontal Axis Hydrokinetic Turbine (HAHT) which harness tidal stream energy the same way Horizontal Axis Wind Turbine (HAWT) extract energy from the wind. While HAHT has been the topic of many researches over the past decade, design of hydrofoils plays a vital role in increasing the structural strength of the blade and maximizing the output of the marine current turbines. In this context, a numerical investigation is conducted in this research in which new hydrofoil for marine current turbines underwater conditions was designed and evaluated. The turbine blade is designed using XFLR5 code and QBlade which is a Blade-Element Momentum solver with a blade design feature. Then, the hydrodynamic performance of hydrofoil was tested using Computational Fluid Dynamics (CFD) consisting of lift and drag coefficients, and velocities distribution. The results showed that the new design of the hydrofoil of marine current turbine blade maintained a CPower value of 50% more from normal range at the TSR 5 to 9 and 51% more at TSR = 6,5 in the performance curve.
Domaine de référence : EMR
Auteur Nachtane M., Tarfaoui M., Saifaoui D., Rouway M.
Année de parution : 2020.
Mots-clés : BE, CFD, Hydrodynamic, Marine current turbin, New hydrofoil.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Real-time relocation of floating offshore wind turbine platforms for wind farm efficiency maximization : An assessment of feasibility and steady-state potential

Résumé : This work examines the steady-state potential and feasibility of Yaw and Induction-based Turbine Repositioning (YITuR), which is a wind farm control concept that passively repositions floating offshore wind turbines using existing turbine control degrees of freedom. To this end, the Floating Offshore Wind Farm Simulator (FOWFSim) is developed to model steady-state wind farm power production while considering floating platform relocation. Optimization studies are carried out with different floating wind farm design parameters and configurations. The objective is to determine sets of optimal wind turbine operating parameters that relocate floating turbines such that wind farm efficiency is maximized. Results show that the potential of YITuR is starkly limited by wind farm design parameters. In particular, anchors should be placed adequately far from floating platform neutral positions, mooring lines should be sufficiently long, and only specific mooring system orientations permit substantial gains in wind farm efficiency. With specific combinations of these parameters, simulation results show that the efficiency of a 7 × 7 floating offshore wind farm may be raised by 42.7% when implementing YITuR in comparison to greedy operation.
Domaine de référence : EMR
Auteur Kheirabadi Ali C., Nagamune Ryozo
Année de parution : 2020.
Mots-clés : Floating offshore wind farm, Floating platform displacement, Mooring lines, Optimization, Wind farm control, Wind farm modeling.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Mapping of Benthic Habitats at Marine Renewable Energy Sites Using Multibeam Echosounder and Sediment Profile Imaging Technologies

Résumé : Abstract Objectives/Scope The goal of this work was to develop a consistent and semi-automated seafloor survey method for generating high-resolution, benthic habitat maps for environmental assessments and monitoring of marine renewable energy sites.
Domaine de référence : EMR
Auteur Revelas Eugene Charles, Sackmann Brandon Steven, Maher Norman Michael, Jones Craig Alexander
Année de parution : 2020.
Type de document : Article de colloque.
Source : Offshore Technology Conference
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Effects of environmental exposure on the mechanical properties of composite tidal current turbine

Résumé : In order to meet the growing demand for energy and also to fight against global warming, Renewable Marine Energies (RME) appeared as a great opportunity for a real ecological and industrial choice. Tidal current turbines are used to extract this energy and installed on the seabed at locations where the nozzle can be prone to the accidental impact and critical loads. The principal objective of this research is to investigate the effects of environmental exposure on the mechanical properties of composite tidal current turbine, the most advanced features currently available in finite element (FE) Abaqus/Explicit have been employed to simulate the behavior of the composite nozzle under static and dynamic loading conditions. To investigate this situation, a parametric analysis is conducted which deals with the effect of velocity and geometry of the impactor. The mechanical behavior has been analyzed as both kinematic effect due to deflection of the composite structure and dynamic effect caused by the interaction between the impactor and the hydrodynamic and hydrostatic pressures over the loading. The stress and the deformation distribution are presented. On the other hand, damage modeling was formulated based on Hashin criteria for intra-laminar damage. This has been accomplished by forming a user-created routine (VUMAT) and executing it in the Abaqus software.
Domaine de référence : EMR
Auteur Nachtane M., Tarfaoui M., Ait Mohammed M., Saifaoui D., El Moumen A.
Année de parution : 2020.
Mots-clés : Composite materials, Damage mechanics, Environmental degradation, Finite element analysis (FEA), Marine turbine, VUMAT.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Fatigue of Slender Offshore Structures : Moorings, Risers, and Umbilicals

Résumé : Abstract Fatigue is one of the key design considerations for moorings, risers, and umbilicals in offshore floating systems. Due to differences in materials, components, configurations, and functionality, these slender structures have distinct driver
Domaine de référence : EMR
Auteur Wu Yongyan, Wang Tao, Vijayaraghavan Vishnu
Année de parution : 2020.
Type de document : Article de colloque.
Source : Offshore Technology Conference
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Design and Stability Analysis of an Offshore Floating Multi-Turbine Platform

Résumé : The technology of multi-turbine platform design is currently in development which can accommodate multiple turbines on a single platform that results in a reduction of installation and mooring costs. This paper presents a method to analyze the effects of the wake between the wind turbines on a multi-turbine platform and use it to find a suitable distance for spacing the wind turbines on the platform. Jensen wake model, Larsen wake model, and CFD simulations are used for calculating the wake effects. The actuator disk theory is used for modeling the rotor. The RANS equations with the 𝒌−𝝎 SST turbulence model are used for CFD calculations. Based on the results of wake effects the spacing requirements for the wind turbines are calculated and the design of the platform is carried out. Hydrostatic analysis of the modeled platform is done to study the floating stability behavior of the platform. The first order hydrodynamics and wave loadings on the platform are calculated in the frequency domain using the potential flow linear diffraction model. The hydrodynamic analysis is carried out on the platform to predict the wave-body interaction between the platform and the waves.
Domaine de référence : EMR
Auteur Bashetty Srikanth, Ozcelik Selahattin
Année de parution : 2020.
Type de document : Article de revue.
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Duct and blade design for small-scale floating tidal current turbine development and CFD-based analysis of power performance

Résumé : This paper proposes designs for blades and a water velocity amplification device for the development of a 5-kW duct-type floating tidal current turbine. In addition, it verifies the power performance by a CFD simulation. A BEM theory-based algorithm is used for iterative design and analysis to delay the onset of the chronic problem of cavitation in tidal current turbine blades. The HEEDS optimization software connected to CAE tools is applied to optimize the design of the duct shape, thereby improving the efficiency of the tidal current turbine. The performance of the designed turbine is verified using the CFD software STAR CCM+. A wave model is established to reflect the pressure variation in shallow water when analyzing the cavitation and power performance. The power and efficiency at the rated water velocity are 5 kW and 44 %, respectively. The results indicate that power can be stably controlled due to stalling under the high-flow-velocity condition.
Domaine de référence : EMR
Auteur Im Heejeon, Hwang Taegyu, Kim Bumsuk
Année de parution : 2020.
Type de document : Article de revue.
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PROBABILISTIC ANALYSIS OF THE FATIGUE LIFE OF OFFSHORE WIND TURBINE STRUCTURES

Résumé : The structural response of the main components of offshore wind turbines (OWTs) is considerably sensitive to amplification as their excitation frequencies approach the natural frequency of the structure. Furthermore, uncertainties present in the loading conditions, soil and structural properties highly influence the dynamic response of the OWT. In most cases, the cost of the structure reaches around 30% of the entire OWT because conservative design approaches are employed to ensure its reliability. As a result, this study aims to address the following research question: can the structural reliability of OWT under fatigue loading conditions be predicted more consistently? The specific aims are to (1) establish the design parameters that most impact the fatigue life, (2) determine the probability distributions of the design parameters, and (3) predict the structural reliability. An analytical model to determine the fatigue life of the structure under 15 different loading conditions and two different locations were developed. Global sensitivity analysis was used to establish the more important design parameters. Also, a systematic uncertainty quantification (UQ) scheme was employed to model the uncertainties of model input parameters based on their available information. Finally, the framework used reliability analysis to consistently determine the system probability of failure of the structure based on the fatigue limit state design criterion. The results show high sensitivity for parameters usually considered as deterministic values in design standards. Additionally, it is shown that applying systematic UQ produces a better approximation of the fatigue life under uncertainty and more accurate estimations of the structural reliability. Consequently, more reliable and robust structural designs may be achieved without the need for overestimating the offshore wind turbine response.
Domaine de référence : EMR
Auteur Nispel Abraham, Ekwaro-Osire Stephen, Dias João Paulo
Année de parution : 2020.
Type de document : Article de revue.
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Nispel et al. - 2019 - PROBABILISTIC ANALYSIS OF THE FATIGUE LIFE OF OFFS.pdf

Domaine de référence : EMR
Année de parution : 0.
Type de document : Pièce jointe.
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Influence of surface waves on the hydrodynamic performance of a horizontal axis ocean current turbine

Résumé : It is known that surface waves have significant influence on the hydrodynamic performance of ocean current turbines which locate near the water surface. In order to quantitatively analyze the wave influence and reveal the interaction mechanism between the wave and the turbine flow, this paper proposes a three-dimensional transient computational fluid dynamics (CFD) model which can accurately predict the hydrodynamic performance of ocean current turbines under current-wave interaction flow conditions. The influences of two key wave parameters, the wave height and the submerged depth of the turbine, on the hydrodynamic forces and flow structures of a three-bladed horizontal axis ocean current turbine are discussed in depth. It is found that the both the average value and the oscillation amplitude of the torque on the turbine increase with the increased wave height, but decrease with the increase of the submerged depth. It is also found that in the cases of shallow submerged depth, the wake structures of the turbine are affected by the surface wave.
Domaine de référence : EMR
Auteur Tian Wenlong, Ni Xiwen, Mao Zhaoyong, Zhang Tianqi
Année de parution : 2020.
Mots-clés : Computational fluid dynamics (CFD), Hydrodynamics, Ocean current turbine, Tidal turbine, Wave.
Type de document : Article de revue.
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SEM-REV offshore energy site wind-wave bivariate statistics by hindcast

Résumé : Accurate estimation of extreme wind and wave conditions is critical for ocean engineering activities and applications. Various renewable energy offshore structures, particularly floating wind turbines are designed to sustain extreme wind and wave induced loads. Statistics of wind speeds and wave heights is the key input for structural safety and reliability study. Consequently, development of novel robust methods, able to predict extreme wind-wave conditions is essential. This paper discusses criteria for selecting design point by applying recently developed method for estimating extreme wave statistics, based on the hourly wave height and wind speed maxima at the location of interest. Wave and wind data, analyzed in this paper, was obtained from the hindcast model applied to the SEM-REV offshore sea location, near the coast of France, during years 2001–2010. The ECMWF (European Centre for Medium range Weather Forecasting) framework along with the atmospheric model SKIRON were employed to generate accurate hindcast wind-wave hourly data at the location of interest. Note that the SEM-REV site was built within the framework of the CPER (Contrat de Projet Etat-Région) 2007–2013 for the Pays de la Loire region, therefore it is important to note that 2001–2010 data studied in this paper was obtained by hindcast into the time period before SEM-REV began operations. Structural design values are often based on univariate statistical analysis, while actually multivariate statistics is more appropriate for modelling the whole structure. The bivariate analysis of extremes is often poorly understood and generally not adequately considered in most practical measurements/situations, therefore it is important to utilize recently developed bivariate average conditional exceedance rate (ACER2D) method. This paper studies extreme wind speeds and wave heights, that are simultaneously obtained at the same location. Due to less than full correlation between wind speed and wave height, application of the multivariate, or bivariate in the simplest case, extreme value theory is of practical importance. This paper focuses on application of the bivariate ACER2D method for prediction of bivariate extreme value statistics. Finally, this paper suggests how the design point should be chosed based on bivariate analysis. The latter is of particular engineering importance as it presents first application of bivariate wind-wave statistics to a raw SEM-REV site data.
Domaine de référence : EMR
Auteur Gaidai Oleg, Xu Xiaosen, Wang Junlei, Ye Renchuan, Cheng Yong, Karpa Oleh
Année de parution : 2020.
Mots-clés : Bivariate statistics, Extreme value statistics, Offshore wind, SEM-REV energy Site, Wave height statistics.
Type de document : Article de revue.
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Generator Topologies for Horizontal Axis Tidal Turbine

Résumé : Over the last decade, research on technologies to exploit tidal current kinetic energy for renewable electricity generation has had a significant growth. However, as to date, there is not a consensus worldwide on standard Power Take-Off (PTO) systems, due to the current immaturity of tidal energy converter technologies. In most cases, mechanical/electrical power conversion follows well-proven technologies derived by the mature wind-energy sector. However, the peculiarities of tidal energy resource impose ad hoc technology solutions. In this paper, different generator topologies and recent developments for marine tidal energy systems are reviewed and compared. The aim is to provide an overall perspective and identify areas for further development. Among considered technologies, the direct-drive permanent magnet synchronous generator by the full-rated frequency converter (FFC) represents an appealing solution, for reduced system complexity and maintenance requirements and possibility to develop smart Maximum Power Point Tracking (MPPT) strategies.
Domaine de référence : EMR
Auteur Rafiei Mohammad, Salvatore Francesco, Giulii Capponi Fabio, Zamboni Walter, Petrone Giovanni
Année de parution : 2020.
Mots-clés : Horizontal axis tidal turbine, Marine current turbine, Ocean energy, Tidal turbine generator.
Type de document : Article de colloque.
Source : Springer International Publishing
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Comparative analysis of numerical computational techniques for determination of the wind turbine aerodynamic performances

Résumé : The purpose of this paper is to explore and define an adequate numerical setting for the computation of aerodynamic performances of wind turbines of various shapes and sizes, which offers the possibility of choosing a suitable approach of minimal complexity for the future research. Here, mechanical power, thrust, power coefficient, thrust coefficient, pressure coefficient, pressure distribution along the blade, relative velocity contoure at different wind speeds and streamlines were considered by two different methods: the blade element momentum (BEM) and computational fluid dynamics (CFD), within which three different turbulence models were analyzed. The estimation of the mentioned aerodynamic performances was carried out on two different wind turbine blades. The obtained solutions were compared with the experimental and nominal (up-scaled) values, available in the literature. Although the flow was considered as steady, a satisfactory correlation between numerical and experimental results was achieved. The comparison between results also showed, the significance of selection, regarding the complexity and geometry of the analyzed wind turbine blade, the most appropriate numerical approach for computation of aerodynamic performances.
Domaine de référence : EMR
Auteur Peric Bojan, Simonovic Aleksandar, Vorkapic Milos
Année de parution : 2020.
Type de document : Article de revue.
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Second-order hydrodynamic effects on the response of three semisubmersible floating offshore wind turbines

Résumé : Floating structures have become the most feasible solution for supporting wind turbines when offshore wind project move to deeper water. In this paper, a hydrodynamic analysis of three different semisubmersible floating offshore wind turbines is carried out including second-order hydrodynamic effects. The three examined platforms are V-shaped semisubmersible, Braceless semisubmersible and OC4-DeepCwind semisubmersible and are used to support the NREL 5 MW reference wind turbine. The main objective of the present study is to investigate and compare the hydrodynamic response of the three different semisubmersible floaters in two water depths (100 m, and 200 m) under different load conditions. The effects of second-order wave loads on the platform motions and mooring tension are discussed and compared by using different methods including Newman's approximation and the full QTF (Quadratic transfer function) method. The drag effect on the structure motion response is also discussed in this paper. The comparison presented is based on statistical values and response spectra of floating platform motions as well as mooring tensions. The results show that the dynamic response of semisubmersible FOWTs (floating offshore wind turbines) is overestimated when ignoring the Morison drag effect on the columns of the semisubmersible FOWT. The second-order difference wave loads can excite the resonance of motion especially for the platform-pitch motion, which could cause structural failures. The full QTF method should be used to calculate the second-order wave force to better simulate the realistic dynamic response of semisubmersible FOWTs.
Domaine de référence : EMR
Auteur Zhang Lixian, Shi Wei, Karimirad Madjid, Michailides Constantine, Jiang Zhiyu
Année de parution : 2020.
Mots-clés : Hydrodynamic loads, Newman's approximation, Quadratic transfer function, Second-order wave loads, Semisubmersible floating wind turbines.
Type de document : Article de revue.
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Characterisation of underwater operational sound of a tidal stream turbine

Résumé : The underwater sound emitted during the operation of the Atlantis AR1500 turbine, a 1.5 MW three bladed horizontal axis tidal-stream turbine, was measured in the Pentland Firth, Scotland. Most sound was concentrated in the lower frequencies, ranging from 50 to 1000 Hz. Within 20 m of the turbine, third-octave band sound pressure levels were elevated by up to 40 dB relative to ambient conditions. In comparison, ambient noise at these frequencies fluctuated by about 5–10 dB between different tidal states. At the maximum recording distance of 2300 m from the turbine, median sound pressure levels when the turbine was operational were still over 5 dB higher than ambient noise levels alone. A higher frequency, tonal signal was observed at 20 000 Hz. This signal component appears at a constant level whenever the turbine is operational and did not change with turbine rotation rate. It is most likely produced by the turbine's generator. This study highlights the importance of empirical measurements of turbine underwater sound. It illustrates the utility and challenges of using drifting hydrophone systems to spatially map operational turbine signal levels with reduced flow noise artefacts when recording in high flow environments.
Domaine de référence : EMR
Auteur Risch Denise, van Geel Nienke, Gillespie Douglas, Wilson Ben
Année de parution : 2020.
Type de document : Article de revue.
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Numerical study of a concept for major repair and replacement of offshore wind turbine blades

Résumé : Repair and replacement of offshore wind turbine blades are necessary for current and future offshore wind turbines. To date, repair activities are often conducted using huge jack-up crane vessels and by applying a reverse installation procedure. Because of the high costs associated with installation and removal of offshore wind turbine components and the low profit margin of the offshore wind industry, alternative methods for installation and removal are needed. This paper introduces a novel concept for replacement or installation of offshore wind turbine blades. The concept involves a medium-sized jack-up crane vessel and a tower climbing mechanism. This mechanism provides a stable platform for clamping, lowering, and lifting of a blade. A case study of a 5-MW offshore wind turbine is shown, where common engineering practices were applied and numerical simulations of the marine operations were carried out using finite element and multibody simulation tools. Operational limits for wave and wind actions were established to demonstrate the technical feasibility of the proposed concept.
Domaine de référence : EMR
Auteur Guachamin‐Acero Wilson, Jiang Zhiyu, Li Lin
Année de parution : 2020.
Mots-clés : blade replacement, numerical simulation, offshore wind turbine, tower climbing mechanism, wind and waves.
Type de document : Article de revue.
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Experimental Electrical Characterisation of Thermoelectric Generator using Forced Convection Water Cooling

Résumé : Thermoelectric Generator (TEG) provides unique advantages as compared to other heat engines as it is capable to convert heat to electricity directly without having any moving parts. Furthermore, TEG is compact, simple and noiseless and requires very minimal maintenance. This paper presents an experimental and analytical study of a model consisting of a TEG located between a copper water cooling jacket and an aluminium block which acts as a heat spreader. The copper water cooling jacket was used in this study as water has higher thermal capacity than air. Besides, copper is one of highest thermal conductivity materials. TEG characterisation in term of electrical was investigated in this study. Based on the result, it shows a linear proportion relationship between open-circuit voltage and temperature difference across TEG. The result also clearly shows the power output of TEG increases as the temperature gradient across TEG increases. In addition, the impact of water flowrate on TEG power output was also studied. Based on the finding, there was an optimum water flowrate of 80 ml/s. Further increasing the water flowrate is not favourable as it will not increase power output and may lead to higher pumping power for water circulation. At this optimum water flowrate, the maximum power output obtained is equal to 530 mW when TEG hot-side temperature (Th) is 180 ℃.
Domaine de référence : EMR
Auteur Bakar Raihan Abu, Singh Baljit, Remeli Muhammad Fairuz, Seng Ong Kok
Année de parution : 2020.
Type de document : Article de revue.
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Dynamic behaviour of an undulating membrane tidal energy converter under wave and current loading

Résumé : The dynamic behaviour of an undulating tidal energy converter under wave and current loadings is studied. Therefore, a small scale prototype of a damped pre-stressed undulating membrane is tested in a wave and current recirculatory tank. The membrane’s dynamic profile and hydrodynamic forces are measured synchronously with the surface elevation for both regular and irregular waves in current direction. Spectrum analysis reveals that the response to wave loading depends on the wave frequency and is reduced by damping-type power take-off. Coupling between the wave frequency and the main undulation frequency or its harmonics is also observed. An increase of 30% of the forces must be foreseen in case of wave condition in the tested range.
Domaine de référence : EMR
Auteur Träsch Martin, Delacroix Sylvain, Déporte Astrid, Drevet Jean-Baptiste, Gaurier Benoît, Germain Grégory
Année de parution : 2020.
Mots-clés : Fluid–structure interaction, Flume tank, Renewable energy, Tidal energy, Undulating membrane, Wave–current interaction.
Type de document : Article de revue.
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Smart Wireless sensors for Impairment detection of the offshore Wind Turbines

Résumé : The maintenance of Wind farms located in the off shores are highly challenging as the preservation and the operational availability are tedious. The insufficiency in the traditional system for monitoring the conditions of the wind turbines located in the off shores has made this topic an attractive area of research. The proposed method in the paper utilizes the multiple intelligent smart sensors to detect the impairments in the structure of the wind turbines. The sensors utilized in the proposed method estimates the damage index in the wind turbine by engaging the embedded software. The effectiveness of the proposed method was measured by applying it to the off shore wind turbines. The results obtained evinces the minimized cost and the down time in maintaining the off shore wind farms.
Domaine de référence : EMR
Auteur Ranganathan Dr G
Année de parution : 2020.
Type de document : Article de revue.
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MONITORING OF OFFSHORE WIND TURBINES UNDER WAVE AND WIND LOADING DURING INSTALLATION

Résumé : During the single blade installation of offshore wind turbines, relative motion between the blade root and turbine hub can cause a delay in the progression of the installation. This contribution presents the results of a monitoring campaign conducted during the installation of an offshore wind park in the North Sea. The campaign covered different states of the turbines: without rotor blades, with rotor blades, without supplementary damping system and with an installed, tuned mass damper system. The objective of the campaign was to determine the dynamic behaviour of the turbines in correlation with wind and wave data and to determine modal parameters. Accordingly, the turbines have been instrumented with sensors to record accelerations at three different positions. The modal parameters were then obtained using SSI/FDD algorithms. Structural damping is additionally determined with an RDM algorithm, and the results are being compared. The analysis of the data will be presented, including the different stages of the structural damping and the corresponding changes in movement patterns. The results shall be used to verify the load models and the predicted response of the structure.
Domaine de référence : EMR
Auteur Sander Aljoscha, Meinhardt Christian, Thoben Klaus-Dieter
Année de parution : 2020.
Type de document : Article de revue.
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Experimental evaluation of a shrouded horizontal axis hydrokinetic turbine with pre-swirl stators

Résumé : Improving the efficiency and power output of hydrokinetic turbines is critical to making them a viable and cost-effective renewable energy solution. Diffusing shrouds have already been shown to improve the performance of horizontal axis, axial-flow turbines. It has been suggested that adding pre-swirl stators to the shroud could alter the inlet flow so as to maximize net tangential force on the turbine blades, thus increasing power output. There is a scarcity of published physical model test data from pre-swirl stator turbines. The present study explores this concept. Four different pre-swirl stator configurations were designed and tested on a shrouded 3-bladed turbine (26.54 cm diameter) in the 36.5 m towing tank at the United States Naval Academy. Three Reynolds numbers (6.07×104, 8.10×104, and 1.01×105 based on stator chord length), corresponding to flow speeds 0.91 m/s, 1.22 m/s, and 1.52 m/s respectively, were tested. At the lowest Reynolds number, all 4 stator configurations improved the maximum Cp by 5–23% compared to the turbine with shroud only. At the middle and highest Reynolds numbers, the stator effect was mostly neutral, with one configuration showing a negative effect at the highest Reynolds number (i.e., lowered the maximum Cp). These results indicate that pre-swirl stators have the potential to improve turbine performance, particularly at lower Reynolds numbers, where the flow is more laminar and the absolute velocities are lower (for a given blade dimension). Pre-swirl stators also appear to reduce the dependence of performance on Reynolds number, flattening the curve and allowing optimal performance over a wider range of operating conditions. Further analytical and computational studies are recommended to explore these findings further, and to develop broader guidance on when pre-swirl stators are advantageous.
Domaine de référence : EMR
Auteur Gish L. A., Carandang A., Hawbaker G.
Année de parution : 2020.
Mots-clés : Hydrokinetic turbine, Marine current turbine, Performance coefficient, Pre-swirl stator, Shroud.
Type de document : Article de revue.
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Monograf 8 РЕД ПЕЧ.pdf

Domaine de référence : EMR
Année de parution : 0.
Type de document : Pièce jointe.
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Estimation of long-term fatigue damage of fixed substructures using fully-coupled models and non-linear dynamic analysis

Résumé : Typical industry models for Offshore Wind Turbines with fixed substructures are based on decoupled models between the wind turbine and the substructure. It is proved that the complete dynamic response of the structure can only be captured with coupled models. In this paper a fully-coupled model for Offshore Wind Turbines with jacket support is presented. The computational model allows to obtain an accurate response of the whole structure and the dynamic interaction between all the elements. It also allows to reproduce particular effects such as the aerodynamic damping without the need for artificial damping ratios which would be needed in decoupled models. Typical environmental offshore conditions are integrated in the model and the response of the structure is obtained by means of a non-linear time integration algorithm in order to include the effect of the continuous rotation of the blades. A cost-efficient approach for the determination of fatigue-damage in the joints of the jackets is proposed. It is based on short-time simulations which allow to accurately estimate the long-term damage in general. The estimation shows a good agreement when compared to the damage values obtained by performing the whole time-interval simulation.
Domaine de référence : EMR
Auteur Couceiro I., París J., Navarrina F., Ramírez L., Colominas I.
Année de parution : 2020.
Mots-clés : Coupled models, Dynamic analysis, Fatigue estimation, Fixed substructures.
Type de document : Article de revue.
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Synergistic inhibitory effects of free nitrous acid and imidazoline derivative on metal corrosion in a simulated water injection system

Résumé : To maintain the integrity of the internal surfaces of the pipelines in oil and gas industry, chemicals, including corrosion inhibitors and biocides, are commonly dosed to prevent corrosion. Imidazoline and its derivatives are widely used corrosion inhibitors for the protection of oil pipelines, which have been shown effective in reducing general corrosion. As an effective biocide, free nitrous acid (FNA) is suitable to inhibit microbially influenced corrosion, induced by for example sulfate-reducing bacteria. In this paper, we hypothesize that the continuous addition of imidazoline and intermittent dosing of FNA, when used in combination, would yield effective control of both general and pitting corrosions. As a typical imidazoline derivative, N-b-hydroxyethyl oleyl imidazoline (HEI-17) was applied in conjunction with intermittent dosing of FNA in the experimental system, with the results compared with two control systems, one receiving HEI-17 only, and one receiving no chemical dosing. The corrosion properties were monitored with open circuit potential, electrochemical impedance spectroscopy, linear polarization resistance, 3D optical profiling, and weight-loss measurement. Following a single dose of FNA, the general corrosion rates in the experimental reactor dropped up to 50% of that in the reactor receiving continuous HEI-17 dosing (0.27 ± 0.04 vs. 0.54 ± 0.08 mm/y), but gradually recovered to 93.4% of that in 2.5 months. After the FNA treatment, the pitting corrosion was decreased by 64.6% compared with continuous HEI-17 dosing reactor for a month from measuring the cumulative distribution of the pitting depth. HEI-17 treatment alone showed moderate pitting corrosion inhibition effect (approx. 27%), and the FNA treatment inhibited the formation of deep pits effectively. The combined application of HEI-17 and FNA has shown synergistic effects and high efficiency in mitigating MIC in the simulated water injection system. This treatment strategy has strong potential to be applied in the practical oilfield operations.
Domaine de référence : Biocorrosion
Auteur Zhong Huiyun, Shi Zhiming, Jiang Guangming, Yuan Zhiguo
Année de parution : 2020.
Mots-clés : Corrosion inhibition, Free nitrous acid, Imidazoline derivative, Microbially influenced corrosion, Pitting corrosion, Sulfate-reducing bacteria.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

FULLTEXT01.pdf

Domaine de référence : Biocorrosion
Année de parution : 0.
Type de document : Pièce jointe.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Abundance of Fe(III) during cultivation affects the microbiologically influenced corrosion (MIC) behaviour of iron reducing bacteria Shewanella putrefaciens

Résumé : The effect of the presence of Fe(III) during the cultivation on the electrochemical activity and corrosion behaviour of dissimilatory iron reducing bacteria Shewanella putrefaciens was studied by means of ex situ and in situ X-ray absorption near-edge spectroscopy (XANES). Stainless steel AISI 304 and thin iron films were studied as substrates. XANES analysis indicated an accelerated iron dissolution and growth of an oxide/hydroxide film for the culture grown with Fe(III) in comparison to the culture grown in absence of Fe(III). Electrochemical analysis indicated that the biofilm resulted in acceleration of the general corrosion but provides protection against local corrosion.
Domaine de référence : Biocorrosion
Auteur Wurzler Nina, Schutter Jan David, Wagner Ralph, Dimper Matthias, Hecht Dirk Lützenkirchen, Ozcan Ozlem
Année de parution : 2020.
Mots-clés : A. Iron, A. Stainless steel, B. Cyclic voltammetry, B. XANES, C. Microbiological corrosion.
Type de document : Article de revue.
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Effects of temperature on polarity reversal of under deposit corrosion of mild steel in oilfield produced water

Résumé : Under-deposit corrosion (UDC) is one of the main factors leading to perforation or leakage of gathering pipeline in the oilfield. In this paper, galvanic corrosion of mild steel under CaCO3 deposit was investigated by using wire beam electrodes (WBE) in the oilfield-produced water. Potential and galvanic mappings indicated that the wire electrodes covered by CaCO3 deposit mainly acted as anode while the rest bare wire electrodes acted as cathode at the beginning of corrosion, causing apparent UDC. However, the deposit-covered electrodes were finally transformed from anode to cathode along with the bare electrodes from cathode to anode, indicative of intensive galvanic polarity reversal. It is supposed that FeCO3 corrosion products could fill into the deposit layer and form a physical diffusion barrier to block the transportation of aggressive ions from the bulk solution to the metal substrate.
Domaine de référence : Biocorrosion
Auteur Wu Yu-Le, Zhang De-Ping, Cai Guang-Yi, Zhang Xin-Xin, Dong Ze-Hua
Année de parution : 2020.
Mots-clés : diffusion barrier, electrochemical mapping, polarity reversal, Under-deposit corrosion.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

The study of microbiologically influenced corrosion of 2205 duplex stainless steel based on high-resolution characterization

Résumé : Sulfate-reducing bacteria (SRB)-induced corrosion of 2205 duplex stainless steel (DSS) was investigated via novel high-resolution characterization. After 28 days of immersion, the corrosion rate of coupons in the SRB-inoculated medium was 10 times higher than that of coupons in the sterile medium. Corrosion products were absent from the top-part of the biofilm where acidic -COOH was present, which indicated corrosion was not caused by metabolites. SRB clung to the matrix and mutually dissolved, which may favor electron transmission. Extracellular electron transfer (EET), breakage of the passive film and inhibition of passive film repair contributed to SRB-induced corrosion in this study.
Domaine de référence : Biocorrosion
Auteur Cui L. Y., Liu Z. Y., Xu D. K., Hu P., Shao J. M., Du C. W., Li X. G.
Année de parution : 2020.
Mots-clés : 2205 duplex stainless steel, corrosion, Microbiologically influenced, Sulfate-reducing bacterium.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Marine Microbial Response to Heavy Metals : Mechanism, Implications and Future Prospect

Résumé : Growing levels of pollution in marine environment has been a matter of serious concern in recent years. Increased levels of heavy metals due to improper waste disposal has led to serious repercussions. This has increased occurrences of heavy metals in marine fauna. Marine microbes are large influencers of nutrient cycling and productivity in oceans. Marine bacteria show altered metabolism as a strategy against metal induced stress. Understanding these strategies used to avoid toxic effects of heavy metals can help in devising novel biotechnological applications for ocean clean-up. Using biological tools for remediation has advantages as it does not involve harmful chemicals and it shows greater flexibility to environmental fluctuations. This review provides a comprehensive insight on marine microbial response to heavy metals and sheds light on existing knowledge about and paves for new avenues in research for bioremediation strategies.
Domaine de référence : Biocorrosion
Auteur Fulke Abhay B., Kotian Atul, Giripunje Manisha D.
Année de parution : 2020.
Type de document : Article de revue.
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Electrochemical Bacterial Enrichment from Natural Seawater and Its Implications in Biocorrosion of Stainless-Steel Electrodes

Résumé : Microbial electrochemical technologies have revealed the opportunity of electrochemical enrichment for specific bacterial groups that are able to catalyze reactions of interest. However, there are unsolved challenges towards their application under aggressive environmental conditions, such as in the sea. This study demonstrates the impact of surface electrochemical potential on community composition and its corrosivity. Electrochemical bacterial enrichment was successfully carried out in natural seawater without nutrient amendments. Experiments were carried out for ten days of exposure in a closed-flow system over 316L stainless steel electrodes under three different poised potentials (−150 mV, +100 mV, and +310 mV vs. Ag/AgCl). Weight loss and atomic force microscopy showed a significant difference in corrosion when +310 mV (vs. Ag/AgCl) was applied in comparison to that produced under the other tested potentials (and an unpoised control). Bacterial community analysis conducted using 16S rRNA gene profiles showed that poised potentials are more positive as +310 mV (vs. Ag/AgCl) resulted in strong enrichment for Rhodobacteraceae and Sulfitobacter. Hence, even though significant enrichment of the known electrochemically active bacteria from the Rhodobacteraceae family was accomplished, the resultant bacterial community could accelerate pitting corrosion in 316 L stainless steel, thereby compromising the durability of the electrodes and the microbial electrochemical technologies.
Domaine de référence : Biocorrosion
Auteur De La Fuente María José, Daille Leslie K., De la Iglesia Rodrigo, Walczak Magdalena, Armijo Francisco, Pizarro Gonzalo E., Vargas Ignacio T.
Année de parution : 2020.
Type de document : Article de revue.
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Microdefects of Biocorroded Pipe Steel Surfaces and Safety Assessment of Localized Stress Concentrators

Résumé : The effect of sulfate-reducing bacteria (SRB) on the corrosion of steel 20 was investigated. Results demonstrated that the chemical composition of corrosion products, the corrosion rate, and corrosion type were altered due to the adherence of SRB and the subsequent formation of biofilm on the steel 20 surface. The micromechanisms of biocorrosion damage of specimens from pipe steel 20 were quantified on the basis of the microgeometry of the degraded surface and the localization parameters of corrosive stress microconcentrators. Stress concentrators in the vicinity of the micro-cuts, which are the depths of the profilograms, make it possible to evaluate safe (allowable) microcorrosion damage. The proposed approach complements the well-known methods for monitoring biodeterioration of pipe steels. With its help, it was found that a decrease in the corrosion rate of specimens with the addition of an inhibitor does not always clearly indicate its effectiveness. The case where the introduction of an inhibitor led to the destruction of the SRB biofilm on the surface of specimens from steel 20, but caused the activation of local corrosion processes and the formation of a more developed microrelief, is considered. The hollows of such microrelief are potential places of origin of defects, which require additional control.
Domaine de référence : Biocorrosion
Auteur Maruschak Pavlo, Dzura Volodymyr, Prentkovskis Olegas, Lytvynenko Iaroslav, Polutrenko Myroslava
Année de parution : 2020.
Mots-clés : inhomogeneous biofilm, microbiologically influenced corrosion, pipeline steel, stress concentrators.
Type de document : Article de revue.
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Efficacy of Imidazolium and Piperidinium based Ionic Liquids on inhibiting biofilm formation on Titanium and Carbon steel surfaces

Résumé : In the present study, the efficacies of three different cationic and anionic ionic liquids (ILs) on biofilm formation on materials used in cooling water systems were evaluated. Two imidazolium based ILs; 1-Ethyl 3-Methylimidazolium tetrafluoroborate – (IL-E) and 1-Butyl-3-methylimidazolium chloride – (IL-I) with anionic fluoride and chloride groups and one piperidinium based IL, N-methyl-N-propylpiperidinium bis(trifluoromethylsulfonyl)imide – (IL-M) with fluoromethyl group as anion were used. The efficacy of these ILs were evaluated on planktonic and sessile cells of major biofilm formers in cooling water systems using Gram negative bacterium Pseudomonas sp. and Gram positive bacterium Bacillus sp. Further their effect on inhibiting biofilm formation on titanium and carbon steel surfaces were also evaluated. Results showed that planktonic cells of Pseudomonas sp. and Bacillus sp. were effectively inhibited by 25 ppm of IL-M and IL-E, respectively. For both bacteria, 50 ppm of IL-I was enough to inhibit and eradicate the sessile cell formation. Among the three ILs, IL-E was the best in inhibiting the adhesion of bacterial cells on Ti and CS surfaces. These results suggest that Imidazolium based ILs are effective in controlling sessile cell formation and eradicating mature biofilm as compared to piperidinium based IL. Further, Imidazolium based IL with fluoride anion (IL-E) was the best in inhibiting adhesion of these bacterial cells and thereby biofilm formation on material surfaces. This study establishes the feasibility of using ILs in cooling water system for bacterial biofilm control along with other conventional biofouling control methods.
Domaine de référence : Biocorrosion
Auteur Anandkumar B., George R. P., Philip John
Année de parution : 2020.
Mots-clés : biofilm control, carbon steel, imidazolium, Ionic liquids, piperidinium, titanium.
Type de document : Article de revue.
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Enhanced durability, bio-activity and corrosion resistance of stainless steel through severe surface deformation

Résumé : Owing to its good biocompatibility and low cost, stainless steel is one of the most widely utilized biomaterial. However, longtime assessment of stainless steel has shown problems related to material degradation, especially localized corrosion and bio-film formation. In addition, the leaching of toxic nickel and chromium ions from stainless steel leads to additional health complications. Here, we utilized submerged friction stir processing, a severe surface deformation technique for significantly enhancing its durability, bio-activity as well as antibacterial resistance. The processing was done with a wide variation in strain rates to produce tunable surface microstructure. High strain-rate processing resulted in nearly single-phase fine-grained microstructure, while slow strain-rate processing developed a dual-phase fine-grained microstructure. The bio-corrosion rate of processed steel was reduced by more than 60 % along with significant enhancement in the pitting resistance. The processed steel showed nearly no bacterial adhesion/biofilm formation, evaluated using S. aureus and E. coli bacterial strains. Further, the processed stainless steel surface demonstrated minimum leaching of the toxic elements, significantly enhancing its appeal for bio-implant applications. The observed behavior was explained based on the formation of a stable passive layer, rich in Cr2O3, as determined using x-ray photoelectron microscopy (XPS) and increased hydrophilicity.
Domaine de référence : Biocorrosion
Auteur Perumal G., Grewal H. S., Arora H. S.
Année de parution : 2020.
Mots-clés : Bio-corrosion, Bio-films, Cytotoxicity, Grain refinement, Severe surface deformation.
Type de document : Article de revue.
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Two years pitting corrosion of AA5005-H34 aluminium alloy immersed in natural seawater : morphology characterisation

Résumé : Pitting corrosion of aluminium alloy AA5005-H34 immersed in natural sea water for up to 2 years is presented, together with new interpretations of the development of the pitting process over extended exposure periods. Trenching initiated at surface-located Fe-rich intermetallic (IM) particles. It occurred more extensively in sea water compared to atmospheric exposures. With increasing exposures, the pitting morphologies became more complex. Three types, i.e. hemispherical pits (Type 1), crystallographic pits (Type 2) and characteristic ‘petal’-like pits (Type 3), were observed after 12 months. It is suggested that the formation of Type 2 and Type 3 pits occurs at an advanced corrosion stage, and are associated with large Fe-rich IM particles near the metal surface. The influence of marine growth on pitting was negligible.
Domaine de référence : Biocorrosion
Auteur Liang Mengxia, Melchers Robert
Année de parution : 2020.
Mots-clés : Aluminium alloy, morphology, pitting corrosion, SEM.
Type de document : Article de revue.
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Charge-reversal surfactant antibiotic material for reducing microbial corrosion in petroleum exploitation and transportation

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

Domaine de référence : Biocorrosion
Année de parution : 0.
Type de document : Pièce jointe.
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Corrosion of Carbon Steel in Marine Environments : Role of the Corrosion Product Layer

Résumé : This article presents a synthesis of recent studies focused on the corrosion product layers forming on carbon steel in natural seawater and the link between the composition of these layers and the corrosion mechanisms. Additional new experimental results are also presented to enlighten some important points. First, the composition and stratification of the layers produced by uniform corrosion are described. A focus is made on the mechanism of formation of the sulfate green rust because this compound is the first solid phase to precipitate from the dissolved species produced by the corrosion of the steel surface. Secondly, localized corrosion processes are discussed. In any case, they involve galvanic couplings between anodic and cathodic zones of the metal surface and are often associated with heterogeneous corrosion product layers. The variations of the composition of these layers with the anodic/cathodic character of the underlying metal surface, and in particular the changes in magnetite content, are thoroughly described and analyzed to enlighten the self-sustaining ability of the process. Finally, corrosion product layers formed on permanently immersed steel surfaces were exposed to air. Their drying and oxidation induced the formation of akaganeite, a common product of marine atmospheric corrosion that was, however, not detected on the steel surface after the permanent immersion period.
Domaine de référence : Biocorrosion
Auteur Refait Philippe, Grolleau Anne-Marie, Jeannin Marc, Rémazeilles Celine, Sabot René
Année de parution : 2020.
Mots-clés : carbon steel, green rust, iron sulfide, localized corrosion, magnetite, seawater.
Type de document : Article de revue.
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Corrosion of initial pits on abandoned X52 pipeline steel in a simulated soil solution containing sulfate-reducing bacteria

Résumé : In this work, corrosion of an abandoned X52 pipeline steel containing artificial pits with varied depths was investigated in a simulated soil solution containing sulfate-reducing bacteria (SRB). Bio-testing, electrochemical measurements and surface analysis techniques were used to study the SRB-induced corrosion outside and inside the pits. Results show that the SRB tend to accumulate on the specimen surface (i.e., outside the pits), rather than inside the pits, resulting in accelerated corrosion of the steel. As the depth of the pit increases, there are fewer SRB adherent to the steel of the pit wall. Thus, compared to the specimen surface, the pits experience a reduced MIC. A galvanic effect exists between the outside and inside the pits, with the former serving as the anode and the latter as the cathode, further enhancing the corrosion of the steel outside the pits.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Cheng Y. Frank
Année de parution : 2020.
Mots-clés : Corrosion, Pipeline steel, Pits, Soil solution, Sulfate-reducing bacteria.
Type de document : Article de revue.
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Corrosion behavior of API-5L-X42 petroleum/natural gas pipeline steel in South China Sea and Strait of Melaka seawaters

Résumé : This work aims to investigate the corrosion effect of different seawaters surrounding Peninsular Malaysia on the carbon steel of the petroleum/natural gas pipeline. The Tafel extrapolation technique has been applied to evaluate the corrosion rate of the pipeline steel and different locations of natural seawaters have been used as the electrolyte solution. In this experiment, carbon steel pipeline, API-5L-X42 was utilized as the sample and the seawaters were taken from several locations in Peninsular Malaysia, specifically at the South China Sea (Terengganu, Kelantan, Pahang) and the Strait of Melaka (Melaka, Johor, Negeri Sembilan). The corrosion rate calculation and the type of corrosion attack also have been discussed on the basis of the morphology and the metal contents of the seawaters. It was found that the corrosion rate of the carbon steel is relatively higher in the Strait of Melaka seawaters than that of the South China Sea seawaters. The corrosion rate results varied from 0.01 to 0.024 mm/year. Immersion test were carried out to examine the corrosion product formed on the surface of the pipe and from the result, localized corrosion (pitting) and uniform corrosion occurred at the specimen’s surface severely for both seawater electrolytes. In summary, South China Sea is more favorable environment for the application of this type of pipeline steel compared to that of Strait of Melaka.
Domaine de référence : Biocorrosion
Auteur Asyadi Azam Mohd, Sukarti Suziee, Zaimi Muhammad
Année de parution : 2020.
Mots-clés : API-5L-X42 pipeline steel, seawater, South China Sea, Strait of Melaka, Tafel extrapolation.
Type de document : Article de revue.
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Identification and characterization of novel corrosion inhibitor molecules

Résumé : Methods of employing corrosion inhibitors with oxidizing and/or non-oxidizing biocides, such as peroxycarboxylic acids, to provide corrosion protected compositions are disclosed. Various corrosion inhibitors further provide biocidal efficacy in addition to the corrosion protection providing further benefits for application of use. Methods of employing corrosion protected biocide compositions, such as peroxycarboxylic acid compositions, for corrosion protection are particularly well suited for treating fluids intended to flow through pipes, namely in the energy industry, water and paper industries, etc. Methods providing suitable corrosion protection in comparison to untreated systems and corrosion protected systems using conventional corrosion inhibitors, such as quaternary amines and imidazolines commonly used in the industry, are disclosed.
Domaine de référence : Biocorrosion
Auteur Balasubramanian Ramakrishnan, Epps Brian, Moloney Jeremy, Moloney Ethan
Année de parution : 2020.
Mots-clés : biocide, composition, corrosion, ppm, wt.
Type de document : Brevet.
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Bio-competitive exclusion of sulfate-reducing bacteria and its anticorrosion property

Résumé : The bio-competitive exclusion (BCX) method is a practical, environment-friendly, and low-cost method of controlling sulfate-reducing bacteria (SRB) and focuses on research and preliminary applications. In this study, a nitrate-reducing bacteria (NRB) were screened and selected from oil-producing water and identified as heterotrophic Pseudomonas sp. through 16S rDNA. The NRB activation and the SRB inhibition systems were studied via the addition of the bio-activators NO3− and NO2−. In addition, the synergistic inhibitory effect of NRB and molybdate on SRB was studied. Results showed that the inhibitory effect of NO2− was better than that of NO3−. At NO3− to NO2− ratio of 1:4, the inhibitory effect was optimum. The addition of 5% activated NRB and a small amount of molybdic acid salt played a synergistic effect. The optimal inhibition system contained the following: 5% NRB, NO3−/NO2− of 1:4, and the amount of molybdate was 1/5 that of NO3−. In this inhibition system, S2− can maintain an extremely low content, and SRB activity was well inhibited. Static corrosion simulation experiments showed that SRB was the main cause of corrosion. The effects of biological inhibitors, fungicides, and corrosion inhibitors on the corrosion inhibition were investigated. Results showed that the corrosion rate of biological inhibitors was the lowest, and the best effect of corrosion inhibition was achieved. The surface morphology of the corroded steel sheet was analyzed via scanning electron microscope. In addition, the surface corrosion of the steel sheet was low, and no pitting was observed.
Domaine de référence : Biocorrosion
Auteur Lai Ruiqiu, Li Qiang, Cheng Changkun, Shen Hui, Liu Siqi, Luo Yijing, Zhang Zhongzhi, Sun Shanshan
Année de parution : 2020.
Mots-clés : Acidification, Anticorrosion simulation performance, Bio-competitive exclusion technology, Nitrate-reducing bacteria (NRB), Point corrosion, Sulfate-reducing bacteria (SRB).
Type de document : Article de revue.
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Microbiologically influenced corrosion : a review of the studies conducted on buried pipelines

Résumé : <section class="abstract"><h2 class="abstractTitle text-title my-1" id="d802e2">Abstract</h2><p>Buried pipelines are essential for the delivery of potable water around the world. A key cause of leaks and bursts in these pipelines, particularly those fabricated from carbon steel, is the accelerated localized corrosion due to the influence of microbes in soil. Here, studies conducted on soil corrosion of pipelines' external surface both in the field and the laboratory are reviewed with a focus on scientific approaches, particularly the techniques used to determine the action and contribution of microbiologically influenced corrosion (MIC). The review encompasses water pipeline studies, as well as oil and gas pipeline studies with similar corrosion mechanisms but significantly higher risks of failure. Significant insight into how MIC progresses in soil has been obtained. However, several limitations to the current breadth of studies are raised. Suggestions based on techniques from other fields of work are made for future research, including the need for a more systematic methodology for such studies.</p></section>
Domaine de référence : Biocorrosion
Auteur Spark Amy, Wang Kai, Cole Ivan, Law David, Ward Liam
Année de parution : 2020.
Type de document : Article de revue.
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Some thoughts about misconceptions surrounding the term ‘biofilm’

Résumé : The central concept of microbiologically influenced corrosion is ‘biofilm’. However, it is neither a 100% biological fabric nor a film. While biofilms though mechanisms such as establishment of differential aeration cells can accelerate corrosion, under certain circumstances such as thickening may also decelerate corrosion. In this article, these mechanisms will be discussed. Along with that, this author also introduces a new term that can replace the term ‘biofilm’. This new term, ‘temenos’, has been proposed to indicate that when a biofilm forms, electrochemical conditions under the biofilm and those of the bulk will be highly different from each other.
Domaine de référence : Biocorrosion
Auteur Javaherdashti Reza
Année de parution : 2020.
Mots-clés : Microbiologically influenced corrosion (MIC)-biofilm.
Type de document : Article de revue.
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Long-term external microbiologically influenced corrosion of buried cast iron pipes in the presence of sulfate-reducing bacteria (SRB)

Résumé : This paper presents the long-term effect of sulfate-reducing bacteria (SRB) on the corrosion of buried cast iron pipes in soil and culture medium which has no previous research in literature. The comprehensive experimental design for investigating the external corrosion of buried pipes in soil and culture medium is developed in the current research. Coated specimens except their one side simulating the exterior surface of buried pipes are exposed to the SRB for 365 days in both the media. From the test results of corrosion rates and maximum pit depth, significant microbiologically influenced corrosion (MIC) of cast iron in the soil is observed as compared to the culture medium. The test results suggest that the testing of specimens in simulated soil solutions or culture medium instead of natural soil may lead to underestimated corrosion measurements for the buried pipe. The findings of this paper have practical applications for the prediction of failure of buried cast iron pipelines.
Domaine de référence : Biocorrosion
Auteur Wasim Muhammad, Djukic Milos B.
Année de parution : 2020.
Mots-clés : Cast iron, Corrosion rate, Microbiologically influenced corrosion, Pipeline, Sulfate-reducing bacteria.
Type de document : Article de revue.
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Mitigating microbiologically influenced corrosion of an oilfield biofilm consortium on carbon steel in enriched hydrotest fluid using 2,2-dibromo-3-nitrilopropionamide (DBNPA) enhanced by a 14-mer peptide

Résumé : In the oil and gas industry, microbiologically influenced corrosion (MIC) is a major threat to hydrotest, a procedure which is required to certify whether a pipeline can be commissioned. Seawater is frequently used as a hydrotest fluid. In this biofilm prevention lab study, an oilfield biofilm consortium was grown in an enriched artificial seawater anaerobically at 37 °C for 60 days. The combination of 100 ppm (w/w) 2,2-dibromo-3-nitrilopropionamide (DBNPA) + 100 nM (180 ppb) Peptide A (a biofilm dispersal agent) led to extra SRB (sulfate reducing bacteria), APB (acid producing bacteria) and GHB (general heterotrophic bacteria) sessile cell count reductions of 0.9-log, 0.8-log and 0.6-log, respectively, compared with the outcome obtained by using 100 ppm DBNPA only. The Peptide A enhancement also led to extra reductions of 44% in weight loss, 40% in maximum pit depth, and 54% in corrosion current density.
Domaine de référence : Biocorrosion
Auteur Wang Di, Ramadan Mahmoud, Kumseranee Sith, Punpruk Suchada, Gu Tingyue
Année de parution : 2020.
Mots-clés : 2,2-dibromo-3-nitrilopropionamide (DBNPA), Anti-biofilm peptide, Biocide enhancer, Hydrotest, Microbiologically influenced corrosion.
Type de document : Article de revue.
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Microbial community dynamics in a crust formed on carbon steel SS400 during corrosion

Résumé : To obtain information on the mechanism of microbiologically influenced corrosion (MIC) under anaerobic conditions, metabolic processes and microbial community dynamics were analysed for MIC of carbon steel with lake-mud microbial consortium as inoculum. During one month of MIC experiment, the microbial consortium corroded carbon steel with sulphate reduction, methane and acetate production. The bacterial and archaeal community structure in the suspension culture and the crust formed on carbon steel were compared using high-throughput Illumina MiSeq sequencing and quantitative polymerase chain reaction. The data indicated that sulphate-reducing bacterium (Desulfovibrio genus), amino acid-degrading bacterium (Aminobacterium genus) and a hydrogenotrophic methanogen Methanofollis among Archaea increased in the crust. These microbes were estimated to collaboratively induced corrosion of carbon steel under anaerobic condition.
Domaine de référence : Biocorrosion
Auteur Hirano Shin-ichi, Nagaoka Toru, Matsumoto Norio
Année de parution : 2020.
Mots-clés : Aminobacteirum, Carbon steel, Desulfovibrio, microbiological corrosion.
Type de document : Article de revue.
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Corrosion Prevention of Underground Reinjection Pipeline Using Geothermal-powered Impressed Current Cathodic Protection in Lahendong Geothermal Area

Résumé : A low pH Brine that flows through carbon steel pipe to the reinjection well will expose a rapid rate of pipe corrosion. Moreover, underground installation of pipe will multiply this corrosion effect and lead in environment pollution and financial losses. This issue could be reduced by applying novel method of corrosion prevention named Geothermal-powered Impressed Current Cathodic Protection (GICCP). This system utilizes a geothermal power source from heat of geothermal pipeline and converts to electric power by using thermoelectric device. Then the electric power is used in GICCP to develop a high potential difference between the surface of pipe to be protected and an anode. It is expected that the implementation of GICCP could inhibit the corrosion rate, extend the remaining life of pipeline, and reduce downtime period as well as the possibility of financial losses in geothermal industry.
Domaine de référence : Biocorrosion
Auteur Gani Viqar Adly, Ardialim Achmad, Harahap Ahmad Indra Sakti, Pravubinantaka Luhung, Putra Muhammad Albarrosyah, Susanto Heri
Année de parution : 2020.
Type de document : Article de revue.
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Marine bacterial community analysis on 316L stainless steel coupons by Illumina MiSeq sequencing

Résumé : In order to evaluate the corrosive action of microorganisms on 316L metal exposed directly to a marine environment, a system was designed to immerse coupons in seawater. After periods of 30, 60 and 90 days, the coupons were recovered, the corrosion rates evaluated and the biofilm samples on their surface were analyzed by 16S rRNA gene sequencing. The results of the corrosion rate showed an acceleration over the entire experimental period. Alpha diversity measurements showed higher rates after 60 days of the experiment, while abundance measurements showed higher rates after 90 days of exposure to the marine environment. The beta-diversity results showed a clear separation between the three conditions and proximity in the indices between replicates of the same experimental condition. The results of 16S rRNA gene sequencing showed that after 30 days of exposure to seawater, there was massive representativeness of the pioneer bacteria, Gamma and Alphaproteobacteria, with emphasis on the genera Alcanivorax, Oceanospirillum and Shewanella. At the 60-day analysis, the Gammaproteobacteria class remained dominant, followed by Alphaproteobacteria and Flavobacteria, and the main representatives were Flexibacter and Pseudoalteromonas. In the last analysis, after 90 days, a change in the described bacterial community profile was observed. The Gammaproteobacteria class was still the largest in diversity and OTUs. The most predominant genera in number of OTUs were Alteromonas, Bacteriovorax and, Nautella. Our results describe a change in the microbial community over coupons directly exposed to the marine environment, suggesting a redirection to the formation of a mature biofilm. The conditions created by the biofilm structure suggest said condition favor biocorrosion on the analyzed coupons.
Domaine de référence : Biocorrosion
Auteur Capão Artur, Moreira-Filho Paulo, Garcia Maurício, Bitati Suleima, Procópio Luciano
Année de parution : 2020.
Type de document : Article de revue.
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Microbiologically influenced corrosion of carbon steel pipeline in shale gas field produced water containing CO2 and polyacrylamide inhibitor

Résumé : Microbiologically influenced corrosion (MIC) and CO2 corrosion are the common types of corrosion in shale gas fields. In this study, the effect of quaternized polyacrylamide inhibitor on MIC was studied in the produced water from a shale gas field using a circulating loop system with CO2. The result shows that polyacrylamide can inhibit CO2 corrosion. However, in the presence of microorganisms, polyacrylamide failed to inhibit MIC. Microorganisms formed biofilm on the coupon surface. Pitting nucleated underneath the biofilm and developed into cavity-type due to the local acidification. According to crystal structure and chemical composition of matters in the biofilm, the mechanism of microbial acidification leading to pitting corrosion was proposed. The prevention and control strategy for MIC in CO2 environment was discussed.
Domaine de référence : Biocorrosion
Auteur Feng Siqiao, Li Yingchao, Liu Huamin, Liu Qiaoping, Chen Xu, Yu Haobo, Chen Changfeng
Année de parution : 2020.
Mots-clés : Cavity-type pitting, Corrosion inhibitor, Local acidification, MIC, Quaternized polyacrylamide.
Type de document : Article de revue.
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Changes in microbial community in the presence of oil and chemical dispersant and their effects on the corrosion of API 5L steel coupons in a marine-simulated microcosm

Résumé : The influence of crude oil and chemical dispersant was evaluated over planktonic bacteria and biofilms grown on API 5L steel surfaces in microcosm systems. Three conditions were simulated, an untreated marine environment and a marine environment with the presence of crude oil and a containing crude oil and chemical dispersant. The results of coupon corrosion rates indicated that in the oil microcosm, there was a high corrosion rate when compared with the other two systems. Analysis of bacterial communities by 16S rRNA gene sequencing described a clear difference between the different treatments. In plankton communities, the Bacilli and Gammaproteobacteria classes were the most present in numbers of operational taxonomic unit (OTUs). The Vibrionales, Oceanospirillales, and Alteromonadales orders were predominant in the treatment with crude oil, whereas in the microcosm containing oil and chemical dispersant, mainly members of Bacillales order were detected. In the communities analyzed from biofilms attached to the coupons, the most preponderant class was Alphaproteobacteria, followed by Gammaproteobacteria. In the control microcosm, there was a prevalence of the orders Rhodobacterales, Aeromonadales, and Alteromonadales, whereas in the dispersed oil and oil systems, the members of the order Rhodobacterales were present in a larger number of OTUs. These results demonstrate how the presence of a chemical dispersant and oil influence the corrosion rate and bacterial community structures present in the water column and biofilms grown on API 5L steel surfaces in a marine environment.
Domaine de référence : Biocorrosion
Auteur Procópio Luciano
Année de parution : 2020.
Type de document : Article de revue.
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Compositions and Methods for Remediation of Sulfate Reducing Prokaryotes

Résumé : Compositions and methods are provided for use in controlling souring and corrosion causing prokaryotes, such as SRP, by treating oil and gas field environments or treatment fluids with a newly identified bacterial strain ATCC Accession No. PTA-124262 as a self-propagating whole cell that produces an anti-SRP bacteriocin in situ. In another aspect, the methods use one or more toxic peptides or proteins isolated therefrom in methods to control unwanted prokaryotic growth in these environments.
Domaine de référence : Biocorrosion
Auteur Manna Kathleen, Tomlinson Ian a, Thatipelli Abhiram, Janes Christopher, Summer Elizabeth J.
Année de parution : 2020.
Type de document : Brevet.
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Methods for diagnosing, monitoring and mitigating microbiologically influenced corrosion

Résumé : Provided are methods for diagnosing, monitoring and mitigating microbiologically influenced corrosion (MIC). The methods employ steps to determine the nature and concentration of biological signatures, formed through metabolism of microorganisms, and correlating the biological signatures with MIC. Based on such analyses, appropriate MIC mitigation strategies may be implemented so as to efficiently target MIC at sites of interest. The methods advantageously allow selection of appropriate MIC mitigation treatments that correspond to the level of severity of the MIC and based on historical data correlating particular biological signatures with particular MIC risk.
Domaine de référence : Biocorrosion
Auteur Zhang Xiaozhou, Enning Dennis R., Higgins Meytal B., Mand Jaspreet, Cao Fang, Pilloni Giovanni, CHATTERJEE Mohor
Année de parution : 2020.
Mots-clés : biological signatures, interest, method according, mic, samples.
Type de document : Brevet.
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Addressing the slow corrosion rate of biodegradable Fe-Mn : Current approaches and future trends

Résumé : The movement towards the commercialization of biodegradable Fe has been hampered by the perceived slow degradation rate of the metal in physiological environments. The introduction of Fe-Mn alloys offers promise due to its significantly improved biocorrosion rates, excellent biocompatibility, and non-magnetic properties. However, the issue of slow corrosion rates persists in this alloy and its future hinges on addressing this issue. This short review report presents the current approaches to address this problem, the challenges concerning Fe-Mn corrosion, and some future techniques that may improve the degradation rate of Fe-Mn alloys.
Domaine de référence : Biocorrosion
Auteur Venezuela J., Dargusch M. S.
Année de parution : 2020.
Mots-clés : Biocorrosion, Biodegradable metals, Corrosion, Iron-manganese.
Type de document : Article de revue.
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Stress-assisted microbiologically influenced corrosion mechanism of 2205 duplex stainless steel caused by sulfate-reducing bacteria

Résumé : In the present work, we studied the stress-assisted microbiologically influenced corrosion mechanism of 2205 duplex steel caused by sulfate-reducing bacteria (SRB) in simulated seawater environment. The results suggested that SRB have a significant influence on the pitting behavior of 2205 DSS, and stress promotes the MIC behavior. The mechanism proposes that the ferrite phases and high-residual stress regions manifest as the preferential anodic electron donor for SRB respiration due to the galvanic effect caused by the composing duplex phases, high-stress regions and low-stress regions; this outcome leads to the preferential dissolution of ferrite phases and high-stress regions.
Domaine de référence : Biocorrosion
Auteur Yang Xiaojia, Shao Jiamin, Liu Zhiyong, Zhang Dawei, Cui Liying, Du Cuiwei, Li Xiaogang
Année de parution : 2020.
Mots-clés : 2205 DSS, microbiologically influenced corrosion, quasi-in-situ EBSD, SKPFM, sulfate-reducing bacteria.
Type de document : Article de revue.
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Corrosion of X52 pipeline steel in a simulated soil solution with coexistence of Desulfovibrio desulfuricans and Pseudomonas aeruginosa bacteria

Résumé : In this work, corrosion of an X52 pipeline steel was investigated in a simulated soil solution containing Pseudomonas aeruginosa (PAO1), Desulfovibrio desulfuricans (sulfate-reducing bacteria, SRB) or both, where the corrosion rates of the steel are 0.035, 0.076 and 0.060 mm/y, respectively. There is no corrosion enhancement between PAO1 and SRB when they coexist. The presence of PAO1 facilitates the SRB cells to be surrounded by corrosion products, and cannot contribute to corrosion at the identical level to the SRB that are bare to the environment. The three microorganism scenarios cause localized corrosion on the steel.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Cheng Y. Frank
Année de parution : 2020.
Mots-clés : A. steel, B. EIS, B. polarization, B. SEM, B. weight loss, C. microbiological corrosion.
Type de document : Article de revue.
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Study on Microbiologically Influenced Corrosion Resistance of Stainless Steels With Weld Seams

Résumé : Stainless steels are widely used in various industries due to their desirable combination of mechanical properties and corrosion resistance. However, corrosion of stainless steels was reported seriously on the weld seam areas, and it is not exceptive for microbiologically influenced corrosion (MIC). In the present study, MIC resistance of two austenitic stainless steels (A1, A2 for short) and a duplex stainless steel (D1 for short) with weld seams were comparatively studied by measurement of average and maximum pit depths and electrochemical tests. Experimental results showed that the pit depth on the weld seam was much deeper than that on the base metal for all the stainless steels. The variations of linear polarization resistance (RLPR) values on base metal and weld seam showed that weld seam could promote MIC. Thus the study indicated that the weld seam accelerated the MIC. In addition, A1 steel with higher Cu content showed the best MIC resistance, followed by A2 steel with lower Cu content, and D1 steel without Cu addition exhibited the worst resistance to MIC, indicating that Cu addition in stainless steels is speculated to be beneficial to the MIC resistance. The mechanisms of Cu improving the MIC resistance in the stainless steels were discussed.
Domaine de référence : Biocorrosion
Auteur Shi Xianbo, Yang Ke, Yan Maocheng, Yan Wei, Shan Yiyin
Année de parution : 2020.
Mots-clés : Austenitic stainless steel, base metal, Duplex stainless steel, Microbiologically influenced corrosion, Pitting corrosion, Weld seam.
Type de document : Article de revue.
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Influence of Environmental Parameters on Microbiologically Influenced Corrosion Subject to Different Bacteria Strains

Résumé : Microbiologically influenced corrosion (MIC) is capable on weakening the metal’s strength, eventually leads to pipeline leakage, environmental hazard and financial loss. Sulfate reducing bacteria (SRB) is the principal causative organism responsible for external corrosion on steel structures. To date, considerable works have been conducted in Malaysia on the mechanisms of SRB upon MIC on the marine environment instead of underground. Moreover, commercial bacteria strain represents local strain in terms of performance and behavior upon corrosion of steel structure is yet to be proven. Thus, this paper aims to investigate the influence of environmental parameters towards MIC in corroding pipeline. Two types of SRB strain were used designated as SRB ATCC 7757 (commercial) and SRB Sg. Ular (local strain) isolated from Malaysian soil. The behavior of both strains was critically compared by calculating the rate of corrosion upon carbon steel coupons in stipulated environmental parameters. Four influential parameters i.e. pH, temperature, salinity concentration and iron concentration were considered. Collected data presented and analyzed using graphical and statistical analysis, respectively. The results showed the difference of corrosivity between two SRB strains in terms of corrosion behavior upon the X-70 steel coupon. SRB Sg. Ular able to cause severe effects upon steel structure as compared to SRB ATCC 7757 due to its aggressiveness shown by the recorded metal loss data. Thus, future works related to MIC for local environment in particular, should not compromise with the type of SRB strains considered due to differences of performance of the microorganisms onto tested environment and materials.
Domaine de référence : Biocorrosion
Auteur Mohd Ali Muhammad Khairool Fahmy, Ismail Mardhiah, Abu Bakar Akrima, Md. Noor Norhazilan, Yahaya Nordin, Zardasti Libriati, Md. Sam Abdul Rahman
Année de parution : 2020.
Type de document : Article de revue.
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Microbiologically influenced corrosion of X80 pipeline steel by nitrate reducing bacteria in artificial Beijing soil

Résumé : In this work, we investigated microbiologically influenced corrosion (MIC) of X80 pipeline steel caused by nitrate-reducing bacteria Brevibacterium frigoritolerans (B. frigoritolerans) in an artificial Beijing soil using electrochemical measurements and surface analyses under aerobic conditions. The B. frigoritolerans was isolated from the surrounding soil of the X80 pipeline steel specimen in Beijing using culturing and molecular biology techniques. Confocal laser scanning microscopy images showed that the largest pit depth after 14 days due to B. frigoritolerans was approximately 7.16 μm. Electrochemical tests showed that the B. frigoritolerans could change the stability of the corrosion products on the 7th day. Inhomogeneous biofilm and the conductivity of Fe2O3 accelerated the corrosion process. The presence of NH4+ on the surface of the X80 pipeline steel revealed that the B. frigoritolerans acted as a biological cathode to promote the cathodic reaction.
Domaine de référence : Biocorrosion
Auteur Liu Bo, Li Ziyu, Yang Xiaojia, Du Cuiwei, Li Xiaogang
Année de parution : 2020.
Mots-clés : biocatalytic cathodic nitrate reduction, inhomogeneous biofilm, microbiologically influenced corrosion, nitrate-reducing bacteria, X80 pipeline steel.
Type de document : Article de revue.
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SURFACE_COATINGS.pdf

Domaine de référence : Biocorrosion
Année de parution : 0.
Type de document : Pièce jointe.
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Effect of Applied Potential and Sulfate Reducing Bacteria on Corrosion Behavior of X80 Steel in Dagang Soil Simulated Solution

Résumé : The corrosion behavior of X80 steel in Dagang soil simulated solution was verified by potentiostatic immersion test and AC impedance test, and the corrosion morphology of metal surface under different applied potential in bacterial solution and sterile solution was observed by scanning electron microscope (SEM).The results showed that the existence of sulfate reducing bacteria (SRB) can increase the corrosion trend of metals. In the simulated solution, the corrosion of samples became more and more serious with the increase of soaking days. With the negative shift of applied potential, the electrochemical corrosion rate of X80 pipeline steel was lower than that under self-corrosion potential.
Domaine de référence : Biocorrosion
Auteur Key Laboratory of Oil & Gas Storage and Transportation, College of Petroleum Engineering, Liaoning Shihua University, Fushun Liaoning, 113001, China., Sun Xiaoqing
Année de parution : 2020.
Type de document : Article de revue.
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Method And System For Moving Substances And Preventing Corrosion In A Conduit

Résumé : A conduit or pipeline system configured to use a liquid containing fluid, such as water, which typically accumulates in low flow pipelines causing corrosion and accumulation of sediments, to remove sediments and prevent corrosion. The liquid-containing fluid can be introduced into gas lines to remove solids, for example, black powder.
Domaine de référence : Biocorrosion
Auteur Beliaeva Ellina, Barr Michael E.
Année de parution : 2020.
Type de document : Brevet.
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Complete Genome Sequence of Pseudomonas balearica Strain EC28, an Iron-Oxidizing Bacterium Isolated from Corroded Steel

Résumé : Pseudomonas balearica strain EC28 is an iron-oxidizing bacterium isolated from corroded steel at a floating production storage and offloading facility in Australia. Here, we report its complete genome sequence, which comprises 4,642,566 bp with a GC content of 64.43%. The genome harbors 4,164 predicted protein-encoding genes.
Domaine de référence : Biocorrosion
Auteur Salgar-Chaparro Silvia J., Castillo-Villamizar Genis, Poehlein Anja, Daniel Rolf, Machuca Laura L.
Année de parution : 2020.
Type de document : Article de revue.
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Comparison of microbial influenced corrosion in presence of iron oxidizing bacteria (strains DASEWM1 and DASEWM2)

Résumé : Microbial influenced corrosion (MIC) is one of the major concerns in industries due to huge economic losses. Sulfate-reducing bacteria (SRB) are well studied and highly corrosive in nature. However, the MIC mechanism, especially by iron-oxidizing bacteria (IOB) is not yet elucidated. In this context, this study presented the co-relation of extra polymeric substances (EPS) exuded by IOB strains as a key mechanism for MIC of mild steel. Herein, the corrosion behavior of mild steel influenced by EPS of two IOB strains; DASEWM1 and DASEWM2 isolated from river water was investigated. Comparative studies using surface analysis, electrochemical tests and immersion tests in nutrient broth media revealed a higher degree of corrosion in inoculated media (strain DASEWM1 < DASEWM2) than control media. These results were also supported by EIS and FESEM of corroded steel surfaces. Moreover, electrochemical and EPS constituent’s analysis, the correlation between the corrosion rate to the EPS constituents were also studied.
Domaine de référence : Biocorrosion
Auteur Sachan Reena, Singh Ajay Kumar
Année de parution : 2020.
Mots-clés : Biofilm, Corrosion tests, FTIR, Iron oxidizing bacteria, Mild steel, XRD.
Type de document : Article de revue.
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Plus de références Biocorrosion


• Antifouling icone-flux-rss

Electrophoretic deposition of zinc alginate coatings on stainless steel for marine antifouling applications

Résumé : The protection of steel against marine biofouling is usually achieved by the application of protective coatings. In this work, an antifouling coating based on alginate biopolymer was developed using the electrophoretic deposition method. Zinc cations have been incorporated into the material to obtain some anti-algae / bacteria properties and calcium cations have been included to contribute to its jellification. The coatings produces were characterized by XRD, SEM, EDX and XPS techniques: the microscopic coatings fully and uniformly covered the steel samples. Results of the biological assays have demonstrated the impact of the coating on marine bacteria and microalgae; the values are comparable to those obtained in bioassays using copper-based alginate coatings. The antifouling effect of the coatings was equivalent to the potency of a high-volume hydrogel effect. These low-cost biocompatible coatings can be attractive in a wide variety of marine applications.
Domaine de référence : Antifouling
Auteur Nassif L. Abi, Rioual S., Farah W., Fauchon M., Toueix Y., Hellio C., Abboud M., Lescop B.
Année de parution : 2020.
Mots-clés : alginate, bacteria, biofouling, microalgae, Stainless steel, zinc.
Type de document : Article de revue.
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Antifouling activities of immobilized ferrocenyl glucose on glassy carbon surface

Résumé : Polar coatings are used to protect surfaces from marine fouling based on the formation of a hydrated surface layer which acts as a barrier to marine microorganisms. In this context, we have developed a material with glucose bound to a ferrocene to prevent surface absorption. Glucose brings the polarity while the ferrocene has the role of varying the state of charge of the surface. We therefore describe the synthesis of 6-deoxy-6-(4-ferrocenyl-1H-1,2,3-triazol-1-yl)-1-(4-aminophenyl)--D-glucopyranose 6, its immobilization on the surface of a C electrode and develop the methodology used for anti-bacterial testing. We were able to demonstrate that the immobilization of glucose 6 could be done in an artificial seawater environment by oxidation of an amine. The use of a 96 micro-well platform equipped with electrodes for cyclic voltammetry, linked to a potentiostat, allowed the electrical solicitation of the coating in the presence of marine bacteria with a greater number of biological replicates. We have shown that the coating has an antibacterial effect and this effect is accentuated when the coating is electrically stressed resulting in the appearance and disappearance of charge on the ferrocene, a phenomenon that seems to be conducive to colonization by bacteria.
Domaine de référence : Antifouling
Auteur Peigneguy Fanny, Cougnon Charles, Barry-Martinet Raphaëlle, Bressy Christine, Gohier Frederic
Année de parution : 2020.
Type de document : Article de revue.
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Amphiphilic dicyclopentenyl/carboxybetaine containing copolymers for marine fouling-release applications

Résumé : Zwitterionic materials received great attention in recent studies due to their high antifouling potential. Though, their application in practical coatings is still challenging. Amphiphilic polymers have proven to be an effective method to combat fouling in the marine environment. This study reports the incorporation of small amounts of zwitterionic carboxybetaine methacrylate (CBMA) into hydrophobic ethylene glycol dicyclopentenyl ether acrylate (DCPEA). A new set of copolymers with varying amphiphilicities was synthesized and coated on chemically modified glass substrates. The antifouling capabilities were assessed against the diatom Navicula perminuta and multiple species in the field. Unsurprisingly, high diatom densities were observed on the hydrophobic control coatings. The integration of small zwitterionic contents of only ~ 5 wt% was already sufficient to rapidly form a hydrophilic interface that led to a strong reduction of fouling. Ultralow fouling was also observed for the pure zwitterionic coatings in laboratory experiments, but it failed when tested in the real ocean environment. We noticed that the ability to absorb large amounts of water and the diffuse nature of the interphase correlates with the adsorption of silt, which can mask the hydrophilic chemistries and facilitate the settlement of organisms. The amphiphilic coatings showed low fouling in dynamic short-term field exposures which could be explained by a reduced tendency of the coatings for sediment adsorption.
Domaine de référence : Antifouling
Auteur Koschitzki Florian, Wanka Robin, Sobota Lennart, Koc Julian, Gardner Harrison, Hunsucker Kelli Z., Swain Geoffrey W., Rosenhahn Axel
Année de parution : 2020.
Type de document : Article de revue.
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Numerical Study on the Hydrodynamic Performance of Antifouling Paints

Résumé : This study presents a simple numerical method that can be used to evaluate the hydrodynamic performances of antifouling paints. Steady Reynolds-averaged Navier-Stokes equations were solved through a finite volume technique, whereas roughness was modeled with experimentally determined roughness functions. First, the methodology was validated with previous experimental studies with a flat plate. Second, flow around the Kriso Container Ship was examined. Lastly, full-scale results were predicted using Granville’s similarity law. Results indicated that roughness has a similar effect on the viscous pressure resistance and frictional resistance around a Reynolds number of 107. Moreover, the increase in frictional resistance due to roughness was calculated to be approximately 3%–5% at the ship scale depending on the paint.
Domaine de référence : Antifouling
Auteur Karabulut Utku Cem, Özdemir Yavuz Hakan, Barlas Barış
Année de parution : 2020.
Type de document : Article de revue.
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Antifouling properties of PEVE coating modified by BiVO4/BiOIO3 composite photocatalyst

Résumé : The BiVO4/BiOIO3 composite photocatalyst was synthesized by hydrothermal method. The fluorocarbon resin was modified by the addition of a composite photocatalyst. The results showed that under simulated sunlight, the composite coating with the best performance had a sterilization rate of 90.5%. The EIS and photocurrent measurements indicated that due to the heterostructure that formed and the electric field that formed inside, the recombination rate of photogenerated electron–holes were reduced; Trapping experiments indicated that .OH radicals were the main reactive species for the sterilization process. Additionally, the cycle tests revealed the excellent stability of BiVO4/BiOIO3 composites.
Domaine de référence : Antifouling
Auteur Song Yupeng, Zhou Feng
Année de parution : 2020.
Type de document : Article de revue.
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Laser engineering of biomimetic surfaces

Résumé : The exciting properties of micro- and nano-patterned surfaces found in natural species hide a virtually endless potential of technological ideas, opening new opportunities for innovation and exploitation in materials science and engineering. Due to the diversity of biomimetic surface functionalities, inspirations from natural surfaces are interesting for a broad range of applications in engineering, including phenomena of adhesion, friction, wear, lubrication, wetting phenomena, self-cleaning, antifouling, antibacterial phenomena, thermoregulation and optics. Lasers are increasingly proving to be promising tools for the precise and controlled structuring of materials at micro- and nano-scales. When ultrashort-pulsed lasers are used, the optimal interplay between laser and material parameters enables structuring down to the nanometer scale. Besides this, a unique aspect of laser processing technology is the possibility for material modifications at multiple (hierarchical) length scales, leading to the complex biomimetic micro- and nano-scale patterns, while adding a new dimension to structure optimization. This article reviews the current state of the art of laser processing methodologies, which are being used for the fabrication of bioinspired artificial surfaces to realize extraordinary wetting, optical, mechanical, and biological-active properties for numerous applications. The innovative aspect of laser functionalized biomimetic surfaces for a wide variety of current and future applications is particularly demonstrated and discussed. The article concludes with illustrating the wealth of arising possibilities and the number of new laser micro/nano fabrication approaches for obtaining complex high-resolution features, which prescribe a future where control of structures and subsequent functionalities are beyond our current imagination.
Domaine de référence : Antifouling
Auteur Stratakis E., Bonse J., Heitz J., Siegel J., Tsibidis G. D., Skoulas E., Papadopoulos A., Mimidis A., Joel A. -C., Comanns P., Krüger J., Florian C., Fuentes-Edfuf Y., Solis J., Baumgartner W.
Année de parution : 2020.
Mots-clés : Bioinspiration, Biomimetic surfaces, Bionic materials, Laser processing, Surface functionalization.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Ecofriendly silicon-poly(lactic acid) hybrid antifouling coatings

Résumé : Societal and environmental constraints have led to changes in international and European regulations to limit the use of biocides in antifouling paints. In this context, coatings combining fouling release properties and leaching of active molecules are sought. The objectives of this study are to conceive a hybrid system for antifouling paint and to observe the influence of the physio-chemical properties of the binders on its antifouling activity. Poly(lactic acid) (PLA) and poly(dimethylsiloxane) (PDMS) homopolymers have already been used as binders for different antifouling strategies. The use of a block copolymer based on PLA and PDMS is likely to allow the design of paint with biocides release associated to fouling release properties in order to be more efficient with a lower environmental impact. Triblock copolymers with different molar compositions have been synthesized. The properties of the corresponding films have been determined in distilled water (adhesion to the support, hydrophobicity). Then formulated paints have been immersed in Lorient harbor to evaluate their erosion, degradation and antifouling efficacy. Furthermore, their biocide release kinetics were studied in artificial seawater to evaluate their environmental impact. The silicon-poly(lactic acid) paints have shown an efficiency superior to a commercial paint during their in situ immersion (19 months) with a lower biocides amount (14 %).
Domaine de référence : Antifouling
Auteur Azemar Fabrice, Faÿ Fabienne, Réhel Karine, Linossier Isabelle
Année de parution : 2020.
Mots-clés : Antifouling, Environmental impact, Hybrid paints, Poly(lactic acid), Silicon.
Type de document : Article de revue.
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2020 State of the Science Report - Chapter 6 : Changes in Benthic and Pelagic Habitats Caused by Marine Renewable Energy Devices | Tethys

Résumé : The OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World builds on and serves as an update and a complement to the 2013 Final Report for Phase 1 of OES-Environmental and the 2016 State of the Science Report. Its content reflects the most current and pertinent published information about interactions of marine renewable energy (MRE) devices and associated infrastructure with the animals and habitats that make up the marine environment. It has been developed and reviewed by over 60 international experts and scientists from around the world as part of an ongoing effort supported by the OES collaboration that operates within the International Technology Cooperation Framework of the International Energy Agency (IEA).
Domaine de référence : Antifouling
Auteur Hemery L.
Année de parution : 2020.
Type de document : Article de revue.
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Characterization and removal of biofouling from reverse osmosis membranes (ROMs) from a desalination plant in Northern Chile, using Alteromonas sp. Ni1-LEM supernatant

Résumé : Biofouling control in reverse osmosis membranes (ROMs) is challenging due to the high cost of treatments, and reduction in the life of ROMs. This study characterizes the biofouling in the ROMs from a desalination plant and reports its effective removal using the supernatant obtained from Alteromonas sp. strain Ni1-LEM. The characterization of the bacterial community revealed that the most abundant taxa in ROMs were the genera Fulvivirga and Pseudoalteromonas, and unclassified species of the families Flavobacteriaceae and Sphingomonadaceae. This bacterial community significantly decreased upon treatment with the supernatant from Alteromonas sp. Ni1-LEM, resulting in the prevalence of the genus Pseudoalteromonas. Furthermore, this bacterial supernatant significantly inhibited cell adhesion of seven benthic microalgae isolated from ROMs as well as promoting cell detachment of the existing microbial biofilms. The study showed that the extracellular supernatant modified the conformation of extracellular polymeric substances (EPS) in the biofouling of ROMs without any biocidal effects.
Domaine de référence : Antifouling
Auteur Vera-Villalobos Hernán, Pérez Vilma, Contreras Francisco, Alcayaga Valezka, Avalos Vladimir, Riquelme Carlos, Silva-Aciares Fernando
Année de parution : 2020.
Mots-clés : Alteromonas sp., antifouling, beneficial bacteria, biofouling, extracellular polymeric substances.
Type de document : Article de revue.
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Study on the preparation and properties of new environmentally friendly antifouling acrylic metal salt resins containing indole derivative group

Résumé : An indole derivative containing a carbon-carbon double bond was purposefully synthesized by the Friedel-Crafts reaction based on 6-chlorine-1H-indole and characterized by IR, 1H NMR and 13C NMR. Antibacterial and inhibiting algae attachment experiments were carried out on the indole derivative. The indole derivative was indicated to have good antibacterial and algae inhibiting properties, then, was introduced into acrylic metal salt resin. Multifunctional acrylic metal salt resins were synthesized via free radical polymerization and polycondensation reactions using acrylic monomers, the indole derivative, metal salts and naphthenic acid. The synthesized resins were characterized by IR and 1H NMR, and the results showed that these target products were successfully synthesized. The self-polishing and antifouling properties of the multifunctional resins were investigated through inhibiting algae attachment experiment, dynamic simulation experiment, anti-protein adsorption experiment and antifouling test in marine environment. Acrylic metal salt resins containing the indole derivative were proven to have not only self-polishing properties but also better antifouling performance than pure acrylic metal salt resins.
Domaine de référence : Antifouling
Auteur Ni Chunhua, Feng Kang, Li Xia, Zhao Haizhou, Yu Liangmin
Année de parution : 2020.
Mots-clés : Acrylic metal salt resins, Antifouling coating, Antimicrobial, Indole derivative.
Type de document : Article de revue.
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Antifouling and antimicrobial coatings based on sol–gel films

Résumé : Biofouling is an undesirable process in which biological molecules and organisms adhere to a surface. This process causes severe negative effects in various fields including healthcare, water distillation, and marine transportation. Therefore, its prevention is highly explored. Here, the prevention of biofouling by thin films, based on different sol–gel precursors, was studied. Specifically, films were formed by methyltrimethoxysilane (MTMOS), phenyltrimethoxysilane (PTMOS), 3,3,3-trifluropropyltrimethoxysilane (FTMOS), or 3-aminopropyltrimethoxysilane (APTMS) using spin-coating on glass. We found that hydrophobicity alone showed a moderate effect on the number of adsorbed bacteria onto the surface. The APTMS film showed, as expected, antibacterial properties and its combination with FTMOS led to a significant prevention of protein and bacterial adsorption. These results emphasize that a dual effect of antifouling and antibacterial properties, is preferred in the prevention of biomass on surfaces.
Domaine de référence : Antifouling
Auteur Zada Tal, Reches Meital, Mandler Daniel
Année de parution : 2020.
Type de document : Article de revue.
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Climate change and vessel traffic create networks of invasion in marine protected areas

Résumé : Establishment of protected areas to maintain biodiversity requires identification, prioritization and management of stressors that may undermine conservation goals. Nonindigenous species and climate change are critical ecosystem stressors that need greater attention in the context of spatial planning and management of protected areas. Risk of invasion into protected areas needs to be quantified under current and projected climate conditions in conjunction with prioritization of key vectors and vulnerable areas to enable development of effective management strategies. We assessed the likelihood of invasion across networks of marine protected areas (MPAs) to determine how invaded MPAs may compromise MPA networks by sharing nonindigenous species. We evaluated invasion risk in 83 MPAs along Canada's Pacific coast for eight nonindigenous species based on environmental suitability under current and future (average conditions from 2041 to 2070) climate conditions and association with shipping and boating pathways. We applied species distribution models and network analysis of vessel tracking data for 805 vessels in 2016 that connected MPAs. The probability of occurrence within MPAs and the proportion of MPA area that is suitable to the modelled species significantly increased under future climate conditions, with six species reaching over 90% predicted occurrence across MPAs and over 70% of suitable area within MPAs. Vessel traffic created four network clusters of 61 highly connected MPAs that spanned the coastline. Occupancy of over 90% of the MPAs within the clusters was predicted for most species. Synthesis and applications. Our results indicate a high likelihood of marine protected area (MPA) network invasion based on current and future environmental conditions and vectors of spread, and the potential for extensive nonindigenous species distributions within MPAs. Our approach highlights how interacting stressors can exacerbate MPA susceptibility to nonindigenous species, adding further challenges for protected area management. Management planning that invests in understanding connectivity and vector processes (human behaviours) is more likely to derive effective policies to stem the flow of nonindigenous species under both current and future conditions. In particular, biosecurity measures including vessel biofouling regulations and MPA- and MPA network-specific plans for prevention, monitoring and mitigation of nonindigenous species are needed.
Domaine de référence : Antifouling
Auteur Iacarella Josephine C., Lyons Devin A., Burke Lily, Davidson Ian C., Therriault Thomas W., Dunham Anya, DiBacco Claudio
Année de parution : 2020.
Mots-clés : automatic identification systems, biosecurity regulations, conservation areas, invasive alien species, network analysis, ship and boat vectors, species distribution models, species range shifts.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

A novel design to investigate the impacts of UV exposure on marine biofouling

Résumé : Ultraviolet light (UV) is currently under investigation as an environmentally friendly alternative for antifouling prevention in the marine environment. A novel apparatus based on a Nautilus shell was designed, to test UV exposure on multiple surfaces with varying distances from a lamp source. Several proof of concept tests were conducted in-situ to determine if the Nautilus design would indeed be an effective method for studying UV in the marine environment. Specifically, the in-situ tests studied the effect of UVC (λ = 254 nm) exposure (continuous and one minute per day) on biofouling settlement at distances ranging from 25 mm to 275 mm. Continuous UV exposure resulted in minimal (≤5% total coverage) settlement, which consisted of biofilms. UV exposure of one minute per day had a greater biofouling settlement with trends observed in the community composition related to distance from the lamp. The coverage of soft fouling organisms decreased with increased distance from the lamp; meanwhile, hard fouling abundance increased with increasing distance. In order to investigate how UV impacts already established fouling, continuous exposure was then applied to a fully developed biofouling community. This resulted in a decrease in total fouling coverage across all distances and live barnacles were only present on surfaces at distances ≥200 mm from the lamp. Overall, the Nautilus design presented a viable option for studying UV in the marine environment and allowing for the identification of UV tolerances within fouling communities.
Domaine de référence : Antifouling
Auteur Braga Cierra, Hunsucker Kelli, Gardner Harrison, Swain Geoffrey
Année de parution : 2020.
Mots-clés : Biofouling, Ship hull coatings, Ultraviolet light, UVC.
Type de document : Article de revue.
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Predicting ship frictional resistance due to biofouling using Reynolds-averaged Navier-Stokes simulations

Résumé : Biofouling reduces the overall hydrodynamic performance of a ship and increases fuel consumption. Four different fouling resistant coatings were experimentally investigated to study their surface roughness properties, during two years of exposure at sea water. An open source RANS solver, OpenFOAM, with integrated rough wall function model, was verified and validated for frictional and total resistance prediction for smooth (no coating) surface conditions. Next, the solver was validated against available CFD and Empirical results for ship frictional resistance prediction with different levels of slime and fouling. Finally, frictional and total resistance was predicted for a ship hull surface with the experimentally studied coatings. The experimental outputs were used to model surface roughness properties of the ship hull, and predict the resistance performance of the ship after one and two years of exposure at sea, with the studied hull coatings. The study reveals that the determination of frictional resistance alone is not enough to understand the required change in propulsion power requirement due to fouling, total drag resistant prediction is also important. It also shows that coatings with initial low roughness may not retain the low resistance property over a long period of exposure to the sea, comparing to other coatings. Overall, the study concludes that CFD can prove to be a very effective tool to study the effect of biofouling on hull properties.
Domaine de référence : Antifouling
Auteur García Sergio, Trueba Alfredo, Boullosa-Falces David, Islam Hafizul, Guedes Soares C.
Année de parution : 2020.
Mots-clés : Biofouling, Fouling resistant coatings, Openfoam, Resistance coefficient, Surface roughness height.
Type de document : Article de revue.
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Bacterial Community Composition in Produced Water of Diyarbak&#305 ;r Oil Fields in Turkey

Résumé : Oil fields harbour a wide variety of microorganisms with different metabolic capabilities. To examine the microbial ecology of petroleum reservoirs, a molecular-based approach was used to assess the composition of bacterial communities in produced water (PW) of Diyarbakır oil fields in Turkey. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments was performed to characterise the bacterial community structure of PW samples and to identify predominant community members after sequencing of separated DGGE bands. The majority of bacterial sequences retrieved from DGGE analysis of PW samples belonged to unclassified bacteria (50%). Among the classified bacteria, Proteobacteria (29.2%), Firmicutes (8.3%), Bacteroidetes (8.3%) and Actinobacteria (4.2%) groups were identified. Pseudomonas was the dominant genus detected in the PW samples. The results of this research provide for, the first time, insight into the complexity of microbial communities in the Diyarbakır oil reservoirs and their dominant constituents.
Domaine de référence : Antifouling
Auteur Tüccar Tuğçe, Ilhan-Sungur Esra, Muyzer Gerard
Année de parution : 2020.
Type de document : Article de revue.
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Highly Effective Functionalized Coatings with Antibacterial and Antifouling Properties

Résumé : One of the current challenges in maritime antifouling is the development of new nanostructured coatings which can replace the old protection coatings based on tributyltin biocides prohibited by EU and US legislation as ecologically dangerous. In our study, antibacterial/antifouling polymer coatings containing innovative dual functionalized nanocapsules demonstrate high antifouling activity in various tests. Capsules are MCM-48 SiO2 nanoparticles loaded with eco-friendly 4,5-dichloro-2-octyl-4-isothiazolin-3-one (DCOIT) antifouling agent and decorated with dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride or dimethyltetradecyl [3-(triethoxysilyl) propyl] ammonium chloride (quaternary ammonium salts, QASs) also possessing antifouling activity. Cross section images of the coatings demonstrated the absence of the capsule aggregates in the coatings with slight increase of the surface roughness. The formulated coatings revealed excellent antibacterial performance against E. coli and Staphylococcus aureus according to ISO 22196:2011 protocol. This antifouling activity was also confirmed by immersion of the coated polyvinyl chloride (PVC) panels at a depth of 8–9 m in the sea (Eilat, Israel). Biofouling coverage of 6.9% was observed for nanocapsules-loaded coatings (5 wt % concentration of nanocapsules) compared to the 49% of the coverage for nonmodified coating after 6 months of immersion. The nanocapsules-loaded coatings with dual antifouling functionality demonstrated antifouling activity even after complete release of encapsulated DCOIT because of chemically attached QAS groups on the nanoparticles surface. Moreover, active antifouling materials presented in nanocapsules do not demonstrate any toxicity to the brine shrimps Artemia salina, which are widely used in the food industry.
Domaine de référence : Antifouling
Auteur Michailidis Marios, Gutner-Hoch Eldad, Wengier Reut, Onderwater Rob, D’Sa Raechelle A., Benayahu Yehuda, Semenov Anton, Vinokurov Vladimir, Shchukin Dmitry G.
Année de parution : 2020.
Type de document : Article de revue.
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Recent Developments and Practical Feasibility of Polymer-Based Antifouling Coatings

Résumé : While nature has optimized its antifouling strategies over millions of years, synthetic antifouling coatings have not yet reached technological maturity. For an antifouling coating to become technically feasible, it should fulfill many requirements: high effectiveness, long-term stability, durability, ecofriendliness, large-scale applicability, and more. It is therefore not surprising that the search for the perfect antifouling coating has been going on for decades. With the discovery of metal-based antifouling paints in the 1970s, fouling was thought to be a problem of the past, yet its untargeted toxicity led to serious ecological concern, and its use became prohibited. As a response, research shifted focus toward a biocompatible alternative: polymer-based antifouling coatings. This has resulted in numerous advanced and innovative antifouling strategies, including fouling-resistant, fouling-release, and fouling-degrading coatings. Here, these novel and exciting discoveries are highlighted while simultaneously assessing their antifouling performance and practical feasibility.
Domaine de référence : Antifouling
Auteur Maan Anna M. C., Hofman Anton H., Vos Wiebe M. de, Kamperman Marleen
Année de parution : 2020.
Mots-clés : antifouling, biomimetic materials, polymer brushes, stimuli-responsive materials, surface modification.
Type de document : Article de revue.
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NIR Triggered Healable Underwater Superoleophobic Coating with Exceptional Anti-Biofouling Performance

Résumé : Although quite some self-healing coatings have been reported to date, underwater healable coatings were involved very limited. Here, we report a novel underwater healable superoleophobic coating through depositing functional SiO2@PDA@Ag particles on the TPA/EVA-70% film. The obtained coating not only possess excellent underwater superoleophobic and antifouling properties, but also quick healable performance by remote NIR irradiation. Thus, it may provide stable and long-lasting underwater antifouling properties against marine growth and oil contamination.
Domaine de référence : Antifouling
Auteur Shang Bin, Zhan Yuan, Chen Min, Wu Limin
Année de parution : 2020.
Mots-clés : Antibiofouling, Coating, Healable, NIR irradiation, Underwater superoleophobicity.
Type de document : Article de revue.
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An experimental test of stationary lay-up periods and simulated transit on biofouling accumulation and transfer on ships

Résumé : Biofouling accumulation on ships’ submerged surfaces typically occurs during stationary periods that render surfaces more susceptible to colonization than when underway. As a result, stationary periods longer than typical port residence times (hours to days), often referred to as lay-ups, can have deleterious effects on hull maintenance strategies, which aim to minimize biofouling impacts on ship operations and the likelihood of invasive species transfers. This experimental study tested the effects of different lay-up durations on the magnitude of biofouling, before and after exposure to flow, using fouling panels with three coating treatments (antifouling, foul-release, and controls), at two sites, and a portable field flume to simulate voyage sheer forces. Control panels subjected to extended stationary durations (28-, 45- and 60-days) had significantly higher biofouling cover and there was a 13- to 25-fold difference in biofouling accumulation between 10-days and 28-days of static immersion. Prior to flume exposure, the antifouling coating prevented biofouling accumulation almost entirely at one site and kept it below 20% at the other. Foul-release coatings also proved effective, especially after flume exposure, which reduced biofouling at one site from >52% to <6% cover (on average). The experimental approach was beneficial for co-locating panel deployments and flume processing using a consistent (standardized) flow regime on large panels across sites of differing conditions and biofouling assemblages. While lay-ups of commercial vessels are relatively common, inevitable, and unavoidable, it is important to develop a better understanding of the magnitude of their effects on biofouling of ships’ submerged surfaces and to develop workable post-lay-up approaches to manage and respond to elevated biofouling accumulation that may result.
Domaine de référence : Antifouling
Auteur Davidson Ian C., Smith George, Ashton Gail V., Ruiz Gregory M., Scianni Christopher
Année de parution : 2020.
Mots-clés : Antifouling coating, flume, foul-release coating, introduced species, lay-up, ship biofouling.
Type de document : Article de revue.
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A Test Device for Microalgal Antifouling Using Fluctuating pH Values on Conductive Paints

Résumé : Due to the current dependence on biocidal antifouling coatings for biofouling control, there is a continuing international challenge to develop more environmentally acceptable antifouling systems. Fluctuating the pH values on paint surfaces is one of these approaches. We developed an antifouling test device to investigate algal biofilms on conductive paints by using a flume with electrochemically working test panels and subsequent confocal laser scanning microscopy (CLSM) of biofilms. By employing a pole reversal of direct current, fluctuating pH values on the paint surface were generated. As a consequence of the resulting pH stress, colonization of the paint surface by diatoms decreased substantially. The density of biofilm algae decreased with increasing pH fluctuations. However, breaks between electrochemical treatments should not exceed one hour. Overall, we established an experimental setup for testing the antifouling capabilities of electrodes based on conductive paints, which could be used for further development of these varnishes.
Domaine de référence : Antifouling
Auteur Kamjunke Norbert, Spohn Uwe, Morig Christian, Wagner Georg, Neu Thomas R.
Année de parution : 2020.
Mots-clés : antifouling, biofilm, conductive paint, confocal laser scanning microscopy, electrochemical treatment, flume, pH.
Type de document : Article de revue.
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Increasing flow rate reduces biofouling and colonization by filamentous bacteria in drippers fed with reclaimed wastewater

Résumé : <p>The clogging of drippers due to the development of biofilms reduces the benefits and is an obstacle to the implementation of drip irrigation technology. The geometry of the dripper channel has an impact on the flow behaviours and head loss. The objective of this study was to analyse the influence of hydrodynamic parameters of three types of drippers (flow rates of 1, 2 and 4 l.h-1) fed by reclaimed wastewater on biofilm development kinetics and on the bacterial community. Using optical coherence tomography, we demonstrated that the inlet of the drippers (mainly the first baffle) and vortex zones are the most sensitive area for biofouling. Drippers with the lowest flow rate (1 l.h-1) and the smallest channel section were the favourable areas to biofouling. The low inlet velocity (0.34 m.s-1) in this type of dripper compared to 2 l.h-1 (0.61 25 m.s-1) and 4 l.h-1 (0.78 m.s-1) drippers can favour the deposition and development of biofilms. In addition, the water velocity influenced the structure of the bacterial communities in the biofilm. Low velocity (0.34 m.s-1) favoured the presence of Hydrogenophaga and Pseudoxanthomonas genera at the early stage of biofilm formation and filamentous bacteria belonging to Chloroflexi phylum at the end. So, maintaining a high flow rate and using drippers with a large flow cross-section is an effective way to control the development of biofilms by limiting the presence of filamentous bacteria.</p>
Domaine de référence : Antifouling
Auteur Lequette Kevin, Ait-Mouheb Nassim, Wery Nathalie
Année de parution : 2020.
Type de document : Article de revue.
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Anti-Adhesion Behavior from Ring-Strain Amine Cyclic Monolayers Grafted on Silicon (111) Surfaces

Résumé : In this manuscript, a series of amine tagged short cyclic molecules (cyclopropylamine, cyclobutylamine, cyclopentylamine and cyclohexylamine) were thermally grafted onto p-type silicon (111) hydride surfaces via nucleophilic addition. The chemistries of these grafting were verified via XPS, AFM and sessile droplet measurements. Confocal microscopy and cell viability assay was performed on these surfaces incubated for 24 hours with triple negative breast cancer cells (MDA-MB 231), gastric adenocarcinoma cells (AGS) endometrial adenocarcinoma (Hec1A). All cell types had shown a significant reduction when incubated on these ring-strain cyclic monolayer surfaces than compared to standard controls. The expression level of focal adhesion proteins (vinculin, paxilin, talin and zyxin) were subsequently quantified for all three cell types via qPCR analysis. Cells incubate on these surface grafting were observed to have reduced levels of adhesion protein expression than compared to positive controls (collagen coating and APTES). A potential application of these anti-adhesive surfaces is the maintenance of the chondrocyte phenotype during in-vitro cell expansion. Articular chondrocytes cultured for 6 days on ring strained cyclopropane-modified surfaces was able to proliferate but had maintained a spheroid/aggregated phenotype with higher COL2A1 and ACAN gene expression. Herein, these findings had help promote grafting of cyclic monolayers as an viable alternative for producing antifouling surfaces.
Domaine de référence : Antifouling
Auteur Ching Jing Yuan, Huang Brian J., Hsu Yu-Ting, Khung Yit Lung
Année de parution : 2020.
Type de document : Article de revue.
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An investigation into the effect of hard fouling on the ship resistance using CFD

Résumé : Biofouling is the colonization of underwater surfaces by microorganisms, plants, algae or animals and can be divided into soft and hard fouling. Soft fouling is consisted of algae, slime and grasses and typically has a lower impact on the performance of the ship than hard fouling, which has a calcareous structure. Furthermore, hard fouling can be extremely detrimental to the performance of machinery and coating systems. Within this paper, the effect of hard fouling on the ship resistance is assessed utilizing Computational Fluid Dynamics (CFD). The roughness function model for the hard fouling is implemented within the wall function of the CFD software. Afterwards, numerical simulations of fouled flat plates are performed, and the obtained results are verified and validated with the experimental results published in the literature. Once validated, numerical simulations with implemented roughness function model and roughness length scale, proposed in the literature, can be used for the determination of the effect of hard fouling on the resistance of any arbitrary body. Lastly, the effects of hard fouling on the resistance characteristics of two merchant ships at full-scale are determined utilizing the validated CFD model. Benefits of the proposed method for the determination of the effect of hard fouling on the ship resistance are highlighted and discussed.
Domaine de référence : Antifouling
Auteur Farkas Andrea, Degiuli Nastia, Martić Ivana
Année de parution : 2020.
Mots-clés : CFD, Container ship, Crude carrier, Hard fouling, Resistance characteristics.
Type de document : Article de revue.
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Propeller Performance Penalty of Biofouling : Computational Fluid Dynamics Prediction

Résumé : The negative effect of biofouling on ship resistance has been investigated since the early days of naval architecture. However, for more precise prediction of fuel consumption of ships, understanding the effect of biofouling on ship propulsion performance is also important. In this study, computational fluid dynamics (CFD) simulations for the full-scale performance of KP505 propeller in open water, including the presence of marine biofouling, were conducted. To predict the effect of barnacle fouling on the propeller performance, experimentally obtained roughness functions of barnacle fouling were used in the wall-function of the CFD software. The roughness effect of barnacles of varying sizes and coverages on the propeller open water performance was predicted for advance coefficients ranging from 0.2 to 0.8. From the simulations, drastic effects of barnacle fouling on the propeller open water performance were found. The result suggests that the thrust coefficient decreases while the torque coefficient increases with increasing level of surface fouling, which leads to a reduction of the open water efficiency of the propeller. Using the obtained result, the penalty of propeller fouling on the required shaft power was predicted. Finally, further investigations were made into the roughness effect on the flow characteristics around the propeller and the results were in correspondence with the findings on the propeller open water performance.
Domaine de référence : Antifouling
Auteur Song Soonseok, Demirel Yigit Kemal, Atlar Mehmet
Année de parution : 2020.
Type de document : Article de revue.
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Fluorinated diols modified polythiourethane copolymer for marine antifouling coatings

Résumé : The development of environmentally friendly alternatives is a crucial issue, since the prohibition of tributyltin (TBT)-based antifouling coatings. In this work, a series of fluorinated diols modified polythiourethane (HO-FPTU-x) have been synthesized via a simple and convenient polymerization reaction with HDI, PETMP and various of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol (HOCH2-FB-Al) at the room temperature, and their antifouling properties are explored as well. The laboratory assays and marine field tests (6 months) show that the HO-FPTU-7.5 (with 7.5 wt% HOCH2-FB-Al) coating has shown excellent antifouling/fouling release properties. The side chains of the HO-FPTU polymers simultaneously contain hydrophobic and hydrophilic groups, which construct an “ambiguous’’ surface after immersing into water. The marine organisms may be “confused’’ by the “ambiguous’’ surface and be removed easily during settlement and adhesion. This work provides a facile strategy for designing environment friendly marine antifouling coatings.
Domaine de référence : Antifouling
Auteur Xie Songbo, Wang Jing, Wang Lida, Sun Wen, Lu Zhaoxia, Liu Guichang, Hou Baorong
Année de parution : 2020.
Mots-clés : Amphiphilic, Antifouling coatings, Fluorinated diols, Polythiourethane.
Type de document : Article de revue.
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Novel marine antifouling coatings inspired by corals

Résumé : Biofouling is a major problem facing the marine industry. Since toxic antifouling coatings were banned globally due to their negative impacts on the marine environment, the development of environmental-friendly and efficient antifouling coatings has been identified as a pressing need. As an alternative, the antifouling coatings inspired by corals have attracted a great deal of attention over these years. within the marine environment, corals have evolved an excellent antifouling capability. There are five major antifouling strategies applied by corals, including natural antifoulants, foul release effect, sloughing effect, soft tentacles, and fluorescence effect. In this paper, a brief review is conducted to introduce the antifouling coatings inspired by the five strategies. Moreover, a discussion is conducted about the existing problems with the five strategies and the direction of their further development is indicated.
Domaine de référence : Antifouling
Auteur Tian L., Yin Y., Jin H., Bing W., Jin E., Zhao J., Ren L.
Année de parution : 2020.
Mots-clés : Bioinspired antifouling coatings, Chemical strategy, Corals, Marine biofouling, Physical strategy.
Type de document : Article de revue.
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Electrodeposition of capsaicin-induced ZnO/Zn nanopillar films for marine antifouling and antimicrobial corrosion

Résumé : Zinc oxide with the morphology of nanopillar is promising marine antifouling materials as they can kill adhered bacteria and fungi. The zinc oxide with the morphology of nanopillar has shown super-antibacterial properties on galvanized steel, which makes ZnO/Zn nanopillar films promising in marine antifouling and antimicrobial corrosion. Thus, an efficient approach to coat ZnO/Zn nanopillar films on steel is of great significance. The electrodeposition method is a universal method for both ZnO crystals and galvanized coatings, and it can control the morphologies and structures of the resultant films. Therefore, in this study, capsaicin was added into an alkaline electrolyte to induce the formation of ZnO nanopillars. Due to capsaicin addition to the electrolyte, ZnO/Zn nanopillar films were obtained in a single cathodic electrodeposition. The added capsaicin in the electrolyte was absorbed on the electrodepositing surface by the functional –NH– groups in amide bond. The Zn(OH)42− diffusion was promoted by negatively shifted electrodepositing potential. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results illustrate that regular ZnO nanopillars were obtained when the capsaicin concentration was 0.6 g L−1 in the electrolyte. The resultant ZnO/Zn nanopillar films showed high antibacterial properties in Escherichia coli suspended solutions and relatively low living bacterial coverage, indicating promising application in marine antifouling. Electrochemical evaluation revealed that the obtained capsaicin-induced ZnO/Zn nanopillar films exhibited significantly enhanced corrosion resistance in a sulfate-reducing bacteria (SRB) medium. Moreover, the results illustrate that adding 0.6 g L−1 concentration of capsaicin in the electrolyte yielded the best films, which featured the lowest bacterial coverage and highest corrosion resistance.
Domaine de référence : Antifouling
Auteur Zhai Xiaofan, Ju Peng, Guan Fang, Ren Yadong, Liu Xin, Wang Nan, Zhang Yimeng, Duan Jizhou, Wang Chuanxing, Hou Baorong
Année de parution : 2020.
Mots-clés : Capsaicin, Corrosion resistance, Electrodeposition, Marine antifouling, Sulfate-reducing bacteria, Zinc oxide nanopillars.
Type de document : Article de revue.
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Influence of ns laser texturing of AISI 316L surfaces for reducing bacterial adhesion

Résumé : Nanosecond pulsed laser texturing has been performed on stainless steel with the objective of developing surface treatments to reduce bacterial adhesion on mechanical components in food handling machinery. The adhesion of Escherichia coli (E. coli) on four distinct textures has been investigated with standardised protocols for measurement of antibacterial performance. Surface morphology has been studied in detail for each texture to ascertain the presence of hierarchical structures and determine the role of topography in reducing bacterial adhesion. Despite the absence of sub-micrometric features comparable with bacterial size, this work highlights the crucial role that nanosecond pulsed laser irradiation plays in promoting a thin layer of iron oxide that reduces E. coli adhesion through local repulsive electrostatic interactions.
Domaine de référence : Antifouling
Auteur Romoli Luca, Lazzini Gianmarco, Lutey Adrian H. A., Fuso Francesco
Année de parution : 2020.
Mots-clés : Antibacterial, Laser, Texture.
Type de document : Article de revue.
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Marine Cable Device Adapted for the Prevention of Fouling

Résumé : The present invention provides a marine cable device configured for preventing or reducing biofouling along its exterior surface, which during use is at least temporarily exposed to water. The marine cable device according to the present invention comprises at least one light source configured to generate an anti-fouling light and at least one optical medium configured to receive at least part of the anti-fouling light. The optical medium comprises at least one emission surface configured to provide at least part of said anti-fouling light on at least part of said exterior surface.
Domaine de référence : Antifouling
Auteur Hietbrink Roelant Boudewijn, Salters Bart Andre, Luck Sean M.
Année de parution : 2020.
Type de document : Brevet.
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Antibiofilm, Antifouling, and Anticorrosive Biomaterials and Nanomaterials for Marine Applications

Résumé : Formation of biofilms is one of the most serious problems affecting the integrity of marine structures both onshore and offshore. These biofilms are the key reasons for fouling of marine structures. Biofilm and biofouling cause severe economic loss to the marine industry. It has been estimated that around 10% of fuel is additionally spent when the hull of ship is affected by fouling. However, the prevention and control treatments for biofilms and biofouling of marine structures often involve toxic materials which pose severe threat to the marine environment and are strictly regulated by international maritime conventions. In this context, biomaterials for the treatment of biofilms, fouling, and corrosion of marine structures assume much significance. In recent years, due to the technological advancements, various nanomaterials and nanostructures have revolutionized many of the biological applications including antibiofilm, antifouling, and anticorrosive applications in marine environment. Many of the biomaterials such as furanones and some polypeptides are found to have antibiofilm, antifouling, and anticorrosive potentials. Many of the nanomaterials such as metal (titanium, silver, zinc, copper, etc.) nanoparticles, nanocomposites, bioinspired nanomaterials, and metallic nanotubes were found to exhibit antifouling and anticorrosive applications in marine environment. Both biomaterials and nanomaterials have been used in the control and prevention of biofilms, biofouling, and corrosion in marine structures. In recent years, the biomaterials and nanomaterials were also characterized to have the ability to inhibit bacterial quorum sensing and thereby control biofilm formation, biofouling, and corrosion in marine structures. This chapter would provide an overview of the biomaterials from diverse sources and various category of nanomaterials for their use in antibiofilm, antifouling, and anticorrosion treatments with special reference to marine applications.
Domaine de référence : Antifouling
Auteur Jayaprakashvel Mani, Sami Mnif, Subramani Ramesh, Prasad Ram, Siddhardha Busi, Dyavaiah Madhu
Année de parution : 2020.
Mots-clés : Antibiofilm, Anticorrosion, Antifouling, Biomaterials, Marine structures, Nanomaterials.
Type de document : Chapitre de livre.
Source : Springer International Publishing
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Carbon Nanotube-Based Antimicrobial and Antifouling Surfaces

Résumé : Carbon nanotubes (CNTs) are versatile nanomaterials with outstanding properties that can be used in different fields. This chapter reviews the use of single- and multi-walled CNTs in the development of antimicrobial and antifouling surfaces. The performance of CNT-containing surfaces seems to depend on a multiplicity of factors that can be conjugated in order to improve their activity. A substantially higher body of knowledge has accumulated regarding the use of multi-walled CNTs and their composites and exciting developments in CNT modification and combination with different molecules are being reported. Although some of the available results are promising, contradictory findings suggest that further investigation is needed to validate the antimicrobial and antifouling activities of developed surfaces in a wider range of conditions. The existing evidence seems to indicate that CNTs and their composites will remain a promising strategy to delay bacterial adhesion and reduce biofilm formation in very different environments.
Domaine de référence : Antifouling
Auteur Teixeira-Santos R., Gomes M., Mergulhão F. J., Snigdha S., Thomas Sabu, Radhakrishnan E. K., Kalarikkal Nandakumar
Année de parution : 2020.
Mots-clés : Antifouling activity, Antimicrobial activity, Nanocomposites, Single- and multi-walled carbon nanotubes, Surfaces.
Type de document : Chapitre de livre.
Source : Springer
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Influences and impacts of biofouling in SWRO desalination plants

Résumé : The ability to produce fresh potable water is an ever-growing challenge, especially with an increase in drought conditions worldwide. Due to its capacity to treat different types of water, reverse osmosis (RO) technology is an increasingly popular solution to the water shortage problem. The major restriction associated with the treatment of water by RO technology is the fouling of the RO membrane, in particular through biofouling. Membrane fouling is a multifaceted problem that causes an increase in operating pressure, frequent cleaning and limited membrane lifespan. The current paper summarizes the impact of biofouling of RO membranes used in seawater desalination plants. Following a brief introduction, the elements that contribute to biofouling are discussed: biofilm formation, role of extracellular polymeric substances (EPS), marine environment, developmental phases of biofouling. Following this, is a section on the implications of membrane biofouling especially permeate flux and salt rejection. The final section focuses on the new phenomenon of compression and hydraulic resistance of biofilms. Lastly, considerations on future research requirements on biofouling and its control in seawater reverse osmosis (SWRO) membrane systems are presented at the end of the article.
Domaine de référence : Antifouling
Auteur Jamieson Tamar, Leterme Sophie C.
Année de parution : 2020.
Mots-clés : Aggregates, biofilm, transparent exopolymer particles (TEP).
Type de document : Article de revue.
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Hydrophilic/Hydrophobic Heterogeneity Anti-Biofouling Hydrogels with Well-regulated Rehydration

Résumé : Hydrogels, as a representative of soft and biocompatible material, have been widely used in biosensors, biomedical devices, soft robotics, and the marine industry. However, the ir-recoverability of hydrogels after dehydration, which will cause the loss of original mechanical, optical and wetting properties, has severely restricted their practical applications. At present, this critical challenge of maintaining hydrogels’ accurate character has caused less attention. To address this, here we report a hydrogel based on synergistic effects to achieve both the well-regulated rehydration and deswelling properties. The hydrogel after dehydration can quickly restore its’ original state both on the macro and micro scale. In addition, the hydrogel has excellent mechanical stability after several dehydration-rehydration cycles. All of these properties offer a possibility of water condition endurance and increase the service life. The robust property is attributed to the hydrophilic-hydrophobic and ionic interactions induced by the synergy of hydrophilic/oleophilic hetero-networks. Moreover, zwitterionic segments as hydrophilic network play a vital role to fabricate anti-biofouling hydrogels. The durable and reusable hydrogel may have promising applications for biomedical materials, flexible devices and the marine industry.
Domaine de référence : Antifouling
Auteur Su Xin, Hao Dezhao, Xu Xiuqi, Guo Xinglin, Li Zhengning, Jiang Lei
Année de parution : 2020.
Type de document : Article de revue.
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Ecofriendly Synthesis of Biopolymer Nanocomposites and Its Application as a Potent Marine Antifouling Agent

Résumé : The undesirable colonization of anthropogenic surfaces by organisms in the marine environment is stated as marine biofouling. The biofouling of marine systems is a global concern, with economic impact estimated at billions of dollars. The widely used antifouling biocides including tributyltin tin (TBT) have been previously assimilated into marine paints. Although it has remarkable antifouling performance, it is toxic to the marine environment. Therefore, it is essential to develop ecofriendly antifouling compounds. In the recent times, the physical, chemical, and mechanical properties of nanomaterials have considerably improved the potential applications ranging from environment and energy to healthcare compared with those of bulk materials. Marine antifouling coating is the most effective way for avoiding marine organism attachment till date. However, the cost associated with the commercial antifouling agents and their maintenance is quite high. Therefore, it is indispensable to develop ecofriendly antifouling compounds. This chapter discusses ecofriendly method to produce biopolymer and nanomaterials conglomerating the antimicrobial property of nanoparticles and the unique structure of the biopolymer PHB against marine biofouling.
Domaine de référence : Antifouling
Auteur Kavitha G., Inbakanadan D., Gothandam K. M., Ranjan Shivendu, Dasgupta Nandita, Lichtfouse Eric
Année de parution : 2020.
Mots-clés : Bioplastic, Ecofriendly nanocomposite, Polyhydroxybutyrate.
Type de document : Chapitre de livre.
Source : Springer International Publishing
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A Green Approach to Modify Surface Properties of Polyamide Thin Film Composite Membrane for Improved Antifouling Resistance

Résumé : A green approach based on plasma enhanced chemical vapour deposition (PECVD) method was adopted in this work to modify surface properties of thin film composite (TFC) membranes for improved antifouling resistance during desalination process. Two types of hydrophilic monomers, i.e., acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) was respectively deposited onto the surface of commercial TFC membranes (XLE and NF270) and the effect of plasma deposition time (15 s, 1 min and 5 min) on the membrane physiochemical properties was investigated using different analytical instruments. The deposition of AA and HEMA was able to improve the membrane hydrophilicity owing to the presence of hydroxyl and carboxyl functional groups. However, prolonged plasma polymerization period was not encouraged as it led to the formation of thicker skin layer that significantly reduced water permeability. With 15-s plasma deposition time, AA and HEMA-modified XLE and NF270 membranes could achieve higher NaCl and Na2SO4 rejections as well as demonstrate 100% flux recovery rate. The improved antifouling resistance of modified TFC membranes is mainly due to the improved surface hydrophilicity coupled with greater surface charge properties. This work demonstrated a rapid solvent-free surface modification method that can be employed to enhance TFC membrane properties for desalination process.
Domaine de référence : Antifouling
Auteur Siew Khoo Ying, Jye Lau Woei, Yeow Liang Yong, Karaman Mustafa, Gürsoy Mehmet, Fauzi Ismail Ahmad
Année de parution : 2020.
Mots-clés : Anti-fouling, Hydrophilic monomers, PECVD, Surface modification, TFC membrane.
Type de document : Article de revue.
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Robust Biomimetic Hierarchical Diamond Architecture with Self-cleaning, Antibacterial and Antibiofouling Surface

Résumé : Biofouling is a worldwide problem from healthcare to the marine exploration. Aggressive biofouling, wear, and corrosion lead to severe deterioration in function and durability. Here, micro and nano-structured hierarchical diamond films, mimicking morphology of plant leaves were developed to simultaneously achieve superhydrophobicity, antibacterial efficacy and marine antibiofouling, combined with mechanical and chemical robustness. These coatings were designed and successfully constructed on various commercial substrates, such as titanium alloys, silicon, and quartz glass via a chemical vapor deposition process. The unique surface structure of diamond films reduced bacteria attachment by 90-99%. In the marine environment, these biomimetic diamond films significantly reduced more than 95% adhesion of green algae. The structured diamond films remained mechanical robustness, superhydrophobicity and antibacterial efficacy under high abrasion and corrosive conditions, exhibiting at least 20 times enhanced wear resistance than the bare commercial substrates even after long-term immersion in seawater.
Domaine de référence : Antifouling
Auteur Wang Tao, Huang Lei, Liu Yuzhi, Li Xingxing, Liu Chunhua, Handschuh-Wang Stephan, Xu Yang, Zhao Ying, Tang Yongbing
Année de parution : 2020.
Type de document : Article de revue.
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Microbial communities of orange tubercles in accelerated low water corrosion

Résumé : The rapid degradation of marine infrastructure at the low tide level due to accelerated low water corrosion (ALWC) is a problem encountered worldwide. Despite this, there is limited understanding of the microbial communities involved in this process. We obtained samples of the orange-coloured tubercles commonly associated with ALWC from two different types of steel sheet piling, located adjacent to each other but with different levels of localised corrosion, at a seaside harbour. The microbial communities from the outer and inner layers of the orange tubercles, and from adjacent seawater, were studied by pure culture isolation and metabarcoding of the 16S rRNA genes. A collection of 119 bacterial isolates was obtained from one orange tubercle sample, using a range of media in anaerobic and aerobic conditions. The metabarcoding results showed that sulfur and iron oxidisers were more abundant on the outer section of the orange tubercles compared to the inner layers, where Deltaproteobacteria (which includes many sulfate reducers) were more abundant. The microbial communities varied significantly between the inner and outer layers of the orange tubercles and also with the seawater, but overall did not differ significantly between the two steel sheet types. Hence we saw similar microbial communities in orange tubercles present, but different levels of localised corrosion, for two different types of co-located steel sheet piling. Metallurgical analysis found differences in composition, grain size, ferrite-pearlite ratio and the extent of inclusions present between the two steel types investigated. IMPORTANCE The presence of orange tubercles on marine steel pilings is often used as an indication that accelerated low water corrosion is taking place. We studied the microbial communities in attached orange tubercles on two closely located sheet pilings that were of different steel types. The attached orange tubercles were visually similar, but the extent of underlying corrosion on the different steel surfaces were substantially different. No clear difference was found between the microbial communities present on the two different types of sheet piling. However, there were clear differences in the microbial communities in the corrosion layers of tubercles, which were also different to the microbes present in adjacent seawater. The overall results suggest that the presence of orange tubercles, a single measurement of water quality, or the detection of certain general types of microbes (e.g. sulfate reducing bacteria) should not be taken alone as definitive indications of accelerated corrosion.
Domaine de référence : Biocorrosion , Antifouling
Auteur Phan Hoang C., Wade Scott A., Blackall Linda L.
Année de parution : 2020.
Type de document : Article de revue.
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Active deformation of dielectric elastomer for detection of biofouling

Résumé : Biofouling accumulation on synthetic underwater surfaces presents serious economic problem for the marine industry. When a substrate-bonded dielectric elastomer (DE) is subjected to high voltage, deformations in form of creases can be formed at the surface of the DE. This deformation, has been already demonstrated for the prevention and detachment of biofouling from the surface of DEs. In this work, we add sensing capability to the anti-biofouling effect of active DE surfaces. A device consisting of a metallic plate, a Kapton sheet, and a thin silicone membrane is immersed in conductive solution, which acts as one electrode, with the metal plate being the second electrode. Two different conductive solutions were used 3.5 wt% NaCl and 20 wt% NaCl. The surface deformation of the silicone as a function of applied voltage is monitored under microscope in order to verify electrical measurements. Breakdown measurements of the dielectric material in different conductive solutions are also performed. Because the membrane is made from incompressible elastomer and bonded to a rigid substrate, voltages below the creasing threshold create no deformation in the membrane, and therefore no change in capacitance. Above the voltage threshold, creasing instabilities appear at the surface of the silicone, thus increasing the capacitance of the device. Therefore, the capacitance of the sensor is measured as a function of applied voltage, and the voltage at which the capacitance increases is the threshold voltage at which creases occur. Creases are identified when using both 3.5 wt% NaCl and 20 wt% NaCl as top electrode. Theoretical values of creasing voltage deviate from the experimental measurements. Type of conductive solution is shown to have no significant influence on a breakdown voltage.
Domaine de référence : Antifouling
Auteur Krpovic Sara, Dam-Johansen Kim, Skov Anne Ladegaard, Rosset Samuel, Anderson Iain
Année de parution : 2020.
Type de document : Article de colloque.
Source : International Society for Optics and Photonics
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Green Adhesives : Preparation, Properties, and Applications

Résumé : Green Adhesives: Preparation, Properties and Applications deals with the fabrication methods, characterization, and applications of green adhesives. It also includes the collective properties of waterborne, bio, and wound-healing green adhesives. Exclusive attention is devoted to discussing the applications of green adhesives in biomedical coatings, food, and industrial applications.
Domaine de référence : Antifouling
Auteur Inamuddin, Boddula Rajender, Ahamed Mohd Imran, Asiri Abdullah M.
Année de parution : 2020.
Mots-clés : Science / Chemistry / General.
Type de document : Livre.
Source : John Wiley & Sons
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Effective Fabrication and Characterization of Eco-friendly Nano Chitosan Capped Zinc Oxide Nanoparticles for PEfficient Marine Fouling Inhibition

Résumé : Since the inhibition of organotin as antifouling additives in 2003, many scientists direct their efforts to develop novel environment-friendly marine antifouling additives. This work declares and evaluates the antifouling activity of Nano chitosan capped ZnO nanoparticles against primary biofilm and biofouling. Chitosan nanoparticles were prepared from the shrimp shell obtained, which will be environmentally friendly and will have no adverse effects on the environment's antialgal, antimicrobial and antifungal characteristics. Using co-precipitation method, the present study manages synthesis and characterization of Nano chitosan capped ZnO nanoparticles (NCCZO NPs) and was identified by FTIR, XRD, HRTEM, SEM, EDX, and UV-VIS. NCCZO NPs have been mixed in the prepared formula of inert marine paint. The formulated paints were then brushed twice on PVC panels, hung in a steel frame and immersed in the Mediterranean Sea Eastern Harbor of Alexandria, followed by visual examination and photographic recordings. The findings revealed once 64 days of immersion that (NCCZO NPs) are resistant to tubeworms and barnacles formation due to their functional groups. This inhibition activity was linked to the significant functional groups (hydroxyl and amine) of the NCCZO NPs. The strong antifouling activity makes them promising candidates for new antifouling additives.
Domaine de référence : Antifouling
Auteur El-saied Hend Al-aidy, Ibrahim Ahmed Mohammed
Année de parution : 2020.
Mots-clés : Antifouling, Biofouling, Chitosan, Marine paint, Zinc oxide nanoparticles.
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.