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A review of tidal current energy resource assessment : Current status and trend

Résumé : Renewable energy resources is one of the alternative energy source identified to address the issue of climate change, energy security and economic growth. Tidal energy is a predictable and reliable source of energy where the exploitable capacity is potentially huge, dispersed in different locations globally. The focus of extracting energy from tides has shifted from the traditional tidal barrages to tidal current energy converters. This paper looks into the different aspects that could be considered for tidal current turbines deployment focusing on site specific matters. Identifying the tidal velocity and mean kinetic energy flux is one of the first aspects of resource assessment when identifying a potential site. This ensures that any device deployed would be able to operate optimally. Different installation schemes are considered where currently, seabed installation is the preferred method. Another factor that needs to be considered is the distance of the tidal power plant from shore where the more remote the location the more power transmission cables needed. This reflects on the costs incurred where therefore a balance between the technical and site optimization has to be the most economical as well.
Domaine de référence : EMR
Auteur Rosli R., Dimla E.
Année de parution : 2018.
Mots-clés : Carbon dioxide, current trend, Fossil fuels, Hydrodynamics, marine energy, Meteorology, Renewable energy sources, resource assessment, tidal current, tidal energy, tidal turbine, Wind turbines.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Experimental and numerical study of hydrodynamic responses of a new combined monopile wind turbine and a heave-type wave energy converter under typical operational conditions

Résumé : This paper deals with a new concept by combining a monopile type wind turbine and a heave-type wave energy converter, that is referred as the ‘MWWC’ (Monopile-WT-WEC- Combination) system herein. Hydrodynamic responses of the MWWC system under typical operational seas cases have been investigated by using both time-domain numerical simulations and scale model tests (1:50). For the numerical model, hydrodynamic loads of the monopile and the WEC are calculated by the AQWA code, which is available for modeling multi-body systems including both mechanical and hydrodynamic couplings between the TLP and the WEC. The scale model tests have been done in State Key Laboratory of Costal and Offshore Engineering (SLCOE). The power-take-off (PTO) system of the WEC device is simulated by two nonlinear air-dampers. Main hydrodynamic characteristics of the MWWC system under typical operational sea cases have been clarified. The obtained wave power characteristic and maximum PTO damping force of the WEC are very helpful for the optimal design of the operational performance of the PTO system. Numerical and experimental results are presented and compared, and good agreements are achieved.
Domaine de référence : EMR
Auteur Ren Nianxin, Ma Zhe, Fan Tianhui, Zhai Gangjun, Ou Jinping
Année de parution : 2018.
Mots-clés : Hydrodynamic response, Model tests, Monopile, Wave energy converter, Wind turbine.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Integrated design and implementation of 120-kW horizontal-axis tidal current energy conversion system

Résumé : A pragmatic and detailed sequence for the integrated design and implementation of a 120-kW horizontal-axis tidal current energy conversion system is presented, thus offering a valuable experience that contributes to the progress of tidal energy systems. The overall design of a full-scale system, containing the system design, control concept, and sea trial is provided in its entirety. The system design includes the turbine, pitch system, mechanical drive train, and electrical system. The blade parameters, hydrofoil data, and detailed structures of these electromechanical systems are shown. The control concept, comprising the grid-connected, maximum power point tracking (MPPT), and pitch controls, is proposed according to the analysis of the output power characteristic of the tidal energy system operation. The main objectives include confining the captured power at its rated value for protection when the rated current velocity is exceeded, capturing the maximum power below the rated current velocity, and regulating the active and reactive power to ensure electric power quality. A workshop test and a sea trial are carried out. The in situ experimental results of a complete operating period validated the effectiveness and feasibility of the entire system design, control concept, and experimental method.
Domaine de référence : EMR
Auteur Gu Ya-jing, Liu Hong-wei, Li Wei, Lin Yong-gang, Li Yang-jian
Année de parution : 2018.
Mots-clés : Control concept, Sea trial, System design, Tidal current energy conversion system.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Structural Optimisation of Offshore Wind turbine structures : A Review

Résumé : AbstractStructural optimization of offshore wind turbines is very tough task due to complexity of the problem. The present paper reviews offshore wind turbine structures, one of the more popular forms of renewable energy, including attractions and challenges of electric power generation through onshore and offshore resources. Offshore wind-power generation presents many engineering challenges including: limited guidelines available for analysis and design of foundation/support structures; inadequate logistics for construction/fabrication; and comparatively expensive operation and maintenance costs, which combined result in current cost of energy approximately double that for onshore wind-power generation. Different offshore foundation options are deliberated in terms of general layout, loading characteristics and related fundamental natural frequency. Keywords:offshore wind turbines, jacket supporting structures, Optimization, structural designCite this ArticleShamshad Khan. Structural Optimisation of Offshore Wind Turbine Structures: A Review. Journal of Offshore Structure and Technology. 2017; 4(3):   35–40p.
Domaine de référence : EMR
Auteur Khan Shamshad
Année de parution : 2018.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Short-term extreme response and fatigue damage of an integrated offshore renewable energy system

Résumé : This study addresses short-term extreme response and fatigue damage of an integrated wind, wave and tidal energy system. The integrated concept is based on the combination of a spar type floating wind turbine, a wave energy converter and two tidal turbines. Aero-hydro-mooring coupled analysis is performed in time-domain to capture the dynamic response of the combined concept in a set of environmental conditions. The mean up-crossing rate method is used to evaluate the extreme response, which takes advantage of an extrapolation method to reduce the simulation sample size. The cumulative fatigue damage is computed based on the S-N method. Simulation results show that the tower base fore-aft bending moment is improved, in terms of extreme value and fatigue damage. Nevertheless, the tension force of a mooring line is worsened. The mooring line bears increased maximum tension due to the tidal turbine thrust force and it is subjected to higher fatigue damage load as well.
Domaine de référence : EMR
Auteur Li Liang, Cheng Zhengshun, Yuan Zhiming, Gao Yan
Année de parution : 2018.
Mots-clés : Extreme response, Fatigue damage, Floating wind turbine, Renewable energy, Tidal turbine, Wave energy converter.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Hybrid Foundation System for Offshore Wind Turbine

Résumé : The demand on green and clean energy is increasing all over the world. This urge us to try to reduce the obstacles in this field. One of the main obstacles is the high cost of offshore foundation system of wind turbines. A novel offshore hybrid foundation system is proposed for large offshore wind turbines to try to reduce the construction cost. This new system consists of circular precast concrete plate connected on site (i.e. offshore) to a steel monopole that is smaller than the usual pile size used. Parametric study for different foundations systems including monopiles had been done. The displacements at different locations of the foundation and the rotation at the pile head were analyzed and evaluated using a 3D nonlinear finite element model under field-like loading conditions considering different foundation configurations. This work paves the way for the development of design guidelines for this novel foundation system in offshore wind turbine applications.
Domaine de référence : EMR
Auteur Abdelkader Ahmed, Naggar M. Hesham El
Année de parution : 2018.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Structural Optimisation of Offshore Wind turbine structures : A Review

Résumé : AbstractStructural optimization of offshore wind turbines is very tough task due to complexity of the problem. The present paper reviews offshore wind turbine structures, one of the more popular forms of renewable energy, including attractions and challenges of electric power generation through onshore and offshore resources. Offshore wind-power generation presents many engineering challenges including: limited guidelines available for analysis and design of foundation/support structures; inadequate logistics for construction/fabrication; and comparatively expensive operation and maintenance costs, which combined result in current cost of energy approximately double that for onshore wind-power generation. Different offshore foundation options are deliberated in terms of general layout, loading characteristics and related fundamental natural frequency. Keywords:offshore wind turbines, jacket supporting structures, Optimization, structural designCite this ArticleShamshad Khan. Structural Optimisation of Offshore Wind Turbine Structures: A Review. Journal of Offshore Structure and Technology. 2017; 4(3):   35–40p.
Domaine de référence : EMR
Auteur Khan Shamshad
Année de parution : 2018.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Integration of tidal range energy with undersea pumped storage

Résumé : The deployment of tidal technology is affected by the general bottlenecks associated with all new renewables in respect of finance and integration with the grid. In this research, a development strategy is defined for tidal range projects based on geodynamics, civil engineering, and economics with the aim of assisting policy makers and industry. Criteria related to hydrodynamics, bathymetry, marine structure safety and cost recovery apply to relevant sites and to real data power prices. The case study described is that of the Bay of Bourgneuf on the French Atlantic coast, where a tidal range power plant of 900 MW could optimally be built with respect to sedimentation, water depth, and tidal coefficients. It has been determined that a 30 m-high artificial dam could maximise the harvestable energy (3 TWh). Numerical simulations show that a tidal plant sized at just 700 MW would be cost-efficient, due to the constraints of the grid and to high power curtailment rates (30%). The expected value of the Levelised Cost of Electricity would be around 200€2016/MWh. Integration into the grid could be improved through addition of an innovative underwater energy storage system, rated to one third of the size of the tidal plant. The economics would improve (the LCOE would drop to 170€2016/MWh) due to lower curtailment and to price arbitrage opportunities. Issues related to missing investor money (>3Bln€2016) and unquantifiable positive externalities such as flood protection, energy independency, and clean energy provision are discussed, underpinning the need for regulator support.
Domaine de référence : EMR
Auteur Loisel Rodica, Sanchez-Angulo Martin, Schoefs Franck, Gaillard Alexandre
Année de parution : 2018.
Mots-clés : French atlantic coast, Market value, Sea water pumped storage, Tidal energy.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Optimal design of galvanic corrosion protection systems for offshore wind turbine support structures

Résumé : The current work addresses a mass/cost optimization procedure for galvanic anode cathodic protection (GACP) systems based on both cathodic protection (CP) standards and numerical simulation. An approach is developed for optimizing the number and dimensions of the galvanic anodes, distributing the optimized anodes on the support structure, and finally evaluating the protective potential on the structure during the lifetime by calling the finite element (FE) software COMSOL. An algorithm based on Sequential Quadratic Programming (SQP) is used for optimizing the number and dimensions of the anodes. Both simplified and detailed models are suggested for calculating the protective potential on the structure. The simplified model is selected based on its advantages in terms of calculation time and compatibility with DNV standard data. A time-dependent FE model is employed to take into account the electrical isolation degradation of the structure coating as well as the mass reduction of the anodes during the CP lifetime. The performance of the proposed optimization process is examined on a mono bucket inspired (with some simplifications) by the Dogger Bank metrological mast in England. The optimized designs for different coating and anode types are compared and the best designs in terms of both cost and protective potential during the lifetime are suggested. The achieved results show that the proposed optimization procedure can reduce the cost of the CP system around 70% compared to the original non-optimized CP design of the Dogger Bank metrological mast. Furthermore, evaluating the time-evolution performance of the CP systems can reduce their lifetime uncertainty.
Domaine de référence : EMR
Auteur Sarhadi Ali, Abrahamsen Asger, Stolpe Mathias
Année de parution : 2018.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Fully automatic visual servoing control for work-class marine intervention ROVs

Résumé : ROVs with hydraulic manipulators are extensively used for subsea intervention. With camera feedback from the scene, manipulators are teleoperated and slaved to pilot held master arms. While standard for offshore oil and gas, for challenging applications in waves or currents a new approach is required. We present development of robot arm visual servo control approaches used in manufacturing and the transfer and adaption of these to underwater hydraulic manipulators. This is the first time a visual servoing algorithm for automated manipulation has been developed and verified, through subsea trials, on a commercial work-class ROV with industry standard hydraulic manipulators.
Domaine de référence : EMR
Auteur Sivčev Satja, Rossi Matija, Coleman Joseph, Dooly Gerard, Omerdić Edin, Toal Daniel
Année de parution : 2018.
Mots-clés : Manipulator control, Marine robotics, Robot arm, ROV, Underwater inspection and intervention, Underwater manipulation, Visual servoing.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Sensor Buoy System for Monitoring Renewable Marine Energy Resources

Résumé : In this paper we present a multi-sensor floating system designed to monitor marine energy parameters, in order to sample wind, wave, and marine current energy resources. For this purpose, a set of dedicated sensors to measure the height and period of the waves, wind, and marine current intensity and direction have been selected and installed in the system. The floating device incorporates wind and marine current turbines for renewable energy self-consumption and to carry out complementary studies on the stability of such a system. The feasibility, safety, sensor communications, and buoy stability of the floating device have been successfully checked in real operating conditions.
Domaine de référence : EMR
Auteur García Emilio, Quiles Eduardo, Correcher Antonio, Morant Francisco
Année de parution : 2018.
Mots-clés : marine energy, marine sensor system, remote monitoring, renewable energy, sensor buoy.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Impact of turbulence induced loads and wave kinematic models on fatigue reliability estimates of offshore wind turbine monopiles

Résumé : The cost of offshore wind turbine substructures has a significant impact on competitiveness of the wind energy market and is affected by conservative safety margins adopted in the design phase. This implies that an accurate design load prediction, especially of those resulting in fatigue damage accumulation, may help achieve more cost-effective solutions. In this article, the impact of turbulence and wave loads on fatigue reliability of pile foundations is investigated for a 5-MW offshore wind turbine. Loads obtained by varying turbulence percentiles are compared with those obtained from the full joint probability distribution of wind speed and turbulence through Monte Carlo (MC) simulations, and from the equivalent turbulence level currently adopted by IEC standards. The analyses demonstrate that a lower equivalent turbulence percentile leads to a more realistic and less conservative estimation of fatigue loads. Subsequently, the research focuses on studying the effects of uncertain marine environments on the fatigue load distribution, showing that the latter is insensitive to the random variability of the hydrodynamic coefficients. With respect to the wave kinematic model, a comparison between nonlinear and linear waves clearly suggests that hydrodynamic forces depend significantly on the kinematic model adopted and the operational conditions of the turbine. Furthermore, a term is derived to correct the error introduced by Wheeler stretching at finite water depths. The respective model uncertainties that originate from the nonlinear irregular wave model and Wheeler correction are quantified and employed in a reliability analysis. In a case study, the results are finally compared in terms of estimated probability of failure, with the aim to quantify the influence of environmental models on monopile reliability.
Domaine de référence : EMR
Auteur Colone Lorenzo, Natarajan Anand, Dimitrov Nikolay
Année de parution : 2018.
Mots-clés : Fatigue reliability, Model uncertainty, Monopile foundation, Nonlinear waves, Offshore wind turbine, Turbulence.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Certification Schemes for Marine Renewable Energy Technologies

Résumé : Floating Offshore Wind Turbines (FOWT), Current and Tidal Turbines (CTT), Wave Energy Converters (WEC) and Ocean Thermal Energy Converters (OTEC) are promising Marine Renewable Energy (MRE) technologies. Considering the emerging stage of development of MRE technologies, no dedicated certification scheme has been developed so far by international organizations. Technical specifications are under development in the framework of the International Electrotechnical Commission (IEC) Technical Committee (TC) 114 and IEC Renewable Energy (IECRE) has been recently created. Within IECRE, the Marine Energy Operational Management Committee (ME OMC) is in charge of the development of a conformity assessment system dedicated to MRE. In this context, Bureau Veritas (BV) has issued a Guidance Note NI631 Certification Scheme for Marine Renewable Energy Technologies to support technology developers and speed up commercial phases. The note NI631 covers different types of technology for energy conversion from wind, wave, tidal or temperature gradients at sea. This paper presents the Guidance Note NI631, which purpose is to provide an overview of the certification schemes applicable to MRE technologies, addressing prototype, component, type and project certification. Main objective, scope, intermediary steps to be completed and resulting certificates will be detailed for each certification scheme, as well as their interactions. Finally, focus will be made on a riskbased approach developed by Bureau Veritas to define the reference set of standards used as a basis for certification. A methodology relying on the qualification of new technology process will be detailed when no guidelines or standards are available for the most innovative parts of any MECs, or when existing standards from related sectors, such as wind energy, shipping or offshore Oil&Gas, require adaptations to fit their requirements to the specific MRE conditions
Domaine de référence : EMR
Auteur Boutrot Jonathan, Lariviere-Gillet Nicolas
Année de parution : 2018.
Type de document : Article de colloque.
Source : Offshore Technology Conference
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Do tidal stream energy projects offer more value than offshore wind farms ? A case study in the United Kingdom

Résumé : Marine-based renewable energy could help the United Kingdom (UK) move towards a more sustainable and low-carbon energy system. Today, offshore wind is the prevailing marine renewable technology but there is growing progress towards developing others, such as tidal stream energy (TSE) turbines which capture kinetic energy from tidal currents. Using historical operations data from 18 wind farms and simulated generation data for two TSE sites in the UK, we estimate that TSE projects offer about $10/MWh more in net social benefits than offshore wind projects. This estimate includes the value of energy generated, value of reduced marginal CO2 emissions, cost of visual changes to the landscape, and cost of energy generation forecast errors. However, relative to offshore wind, the increased cost of TSE projects far outweighs the increased social benefits. The levelized cost of energy (LCOE) of TSE projects is expected to be about $74/MWh to $330/MWh higher than offshore wind projects through 2050. Only with optimistic LCOE projections, small TSE projects (20MW) may be competitive (when including increased net social benefits) with small offshore wind projects by 2020
Domaine de référence : EMR
Auteur V Julian, Lamy, L Inês, Azevedo
Année de parution : 2017.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

The surface wave effects on the performance and the loading of a tidal turbine

Résumé : When tidal turbines are utilized in the most energetic waters where there are significant waves, the assessment of the surface wave effects are of great concerns. The objective of this paper is to contribute to a fundamental understanding of surface wave effects on tidal turbines. A numerical model was developed based on the modified Blade Element Momentum theory with an inclusion of added mass effects, wave excitation forces and a one degree-of-freedom (DOF) simulation for turbine rotational motion. The experiments on a 1:25 scaled tidal turbine were performed in a towing tank. It is shown that the surface waves did not affect the average loads and power output, but caused severe periodical oscillations. The amplitudes of the cyclic thrust and torque could reach up to 50% of the mean value induced by the incident waves with period of 1.6 s and height of 14 cm. Non-dimensional response amplitude operators (RAOs) of thrust and torque were proved to be sensitive to submergence of the turbine. The wave induced torque and thrust tend to a fixed value when the incident wave length is much longer than the water depth, which provides an approximate assessment of the surface wave effects on tidal turbines.
Domaine de référence : EMR
Auteur Guo Xiaoxian, Yang Jianmin, Gao Zhen, Moan Torgeir, Lu Haining
Année de parution : 2018.
Mots-clés : Blade Element Momentum, Regular waves, Tidal turbine, Towing experiments, Wave loads.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

A review of foundations of offshore wind energy convertors : Current status and future perspectives

Résumé : This paper reviews foundations for offshore wind energy convertors considering the significant growth of offshore wind energy since the early 2000s. The characteristics of various foundation types (i.e., gravity, pile, suction caisson, and float type) and the current status of field application are discussed. Moreover, the mechanical characteristics of soil are described in the sense that these characteristics including modulus, strength, damping, and modulus degradation of soil play critical roles for the design of offshore foundations. By using these mechanical properties of soil, theoretical studies to consider structure-soil interaction are classified (into equivalent spring models, distributed spring models, and continuous element models) and explained. Field and laboratory experiments on the response of structure embedded in soil to static and dynamic loads are discussed. Based on the review of previous studies, directions for future research and study on offshore wind turbine are suggested.
Domaine de référence : EMR
Auteur Oh Ki-Yong, Nam Woochul, Ryu Moo Sung, Kim Ji-Young, Epureanu Bogdan I.
Année de parution : 2018.
Mots-clés : Offshore foundations, Offshore wind energy convertors, Offshore wind turbines, Structure-soil interaction.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Offshore Wind Energy Technology

Résumé : A COMPREHENSIVE REFERENCE TO THE MOST RECENT ADVANCEMENTS IN OFFSHORE WIND TECHNOLOGY Offshore Wind Energy Technology offers a reference based on the research material developed by the acclaimed Norwegian Research Centre for Offshore Wind Technology (NOWITECH) and material developed by the expert authors over the last 20 years. This comprehensive text covers critical topics such as wind energy conversion systems technology, control systems, grid connection and system integration, and novel structures including bottom-fixed and floating. The text also reviews the most current operation and maintenance strategies as well as technologies and design tools for novel offshore wind energy concepts. The text contains a wealth of mathematical derivations, tables, graphs, worked examples, and illustrative case studies. Authoritative and accessible, Offshore Wind Energy Technology: Contains coverage of electricity markets for offshore wind energy and then discusses the challenges posed by the cost and limited opportunities Discusses novel offshore wind turbine structures and floaters Features an analysis of the stochastic dynamics of offshore/marine structures Describes the logistics of planning, designing, building, and connecting an offshore wind farm Written for students and professionals in the field, Offshore Wind Energy Technology is a definitive resource that reviews all facets of offshore wind energy technology and grid connection.
Domaine de référence : EMR
Auteur Anaya-Lara Olimpo, Tande John Olav, Uhlen Kjetil, Merz Karl
Année de parution : 2018.
Mots-clés : Science / Energy, Technology & Engineering / Power Resources / General.
Type de document : Livre.
Source : John Wiley & Sons
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Water Flow Power Generator

Résumé : A water flow power generator includes a nacelle, a vane wheel that is disposed so as to be rotatable relative to the nacelle, and that is rotated by a water flow while including a plurality of blades, a power generator that is disposed inside the nacelle, and that generates electric power by using rotating power transmitted from the vane wheel, and a vane wheel rotation stopping mechanism that is disposed in the nacelle, that includes a rod which can enter the inside of a rotational trajectory of the vane wheel, and that stops the rotation of the vane wheel.
Domaine de référence : EMR
Auteur UMEDA Akihiko, ASANO Shin
Année de parution : 2018.
Type de document : Brevet.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Evaluation of durability of composite materials applied to renewable marine energy : Case of ducted tidal turbine

Résumé : Composite materials are used in many marine structures such as renewable marine energy conversion systems because of their fairly good mechanical properties and especially their low densities compared to traditional materials. The most advanced features currently available in finite element (FE) Abaqus/Explicit have been employed to simulate the behavior of the composite nozzle under hydrodynamic and impact loading. A hydrodynamic analysis was considered to design the nozzle turbine and the hydrodynamic pressure obtained was then implemented as boundary conditions to a FE code. The goal of this article is to evaluate the durability of composite materials of a ducted tidal turbine under critical loads (hydrodynamic and hydrostatic pressures) with the implementation of a failure criterion using the finite element analysis (FEA). The mechanical behavior was analyzed for two materials (Carbon–epoxy/ Glass–polyester). 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., Saifaoui D., El Moumen A., Hassoon O. H., Benyahia H.
Année de parution : 2018.
Mots-clés : Ducted tidal turbine, Finite element analysis, Marine composite structures, VUMAT.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Maximum power point tracking for tidal turbine generator

Résumé : Tidal energy is a clean and environment-friendly energy source. It has many advantages such as sustainability, low initial cost, abundant and highly predictable due to its regular pattern. The working principle of tidal energy conversion system (TECS) is to use the potential and kinetic energy of the ocean waves caused by the celestial gravitation to drive the turbine that is coupled with a generator to produce electricity. However, due to the physical structure of the generator, the power output is closely related with water speed, direction, load amount, etc., which show highly non-linear characteristics. The water speed and direction of the tidal stream are closely related to the moon phase, which can be considered as deterministic factor. However, there are non-deterministic factors such as sea habitat migration, seaweed entanglement, bio-foiling, etc. that can make the power output sub-optimal. In order to extract the maximum potential of tidal power in terms of electricity, the maximum power point (MPP) needs to be monitored and tracked in real time. In this paper, we will review state-of-the-art MPP tracking (MPPT) of TECS such as optimal tip speed ratio (TSR) method, optimum relation based (ORB) method, and perturb and observe (P&O) method. Based on the reviewed methods, we summarize the principles, advantages and limitations of the methods, and show the performance of MPPT based on P&O in TECS with simulated results.
Domaine de référence : EMR
Auteur Wen M., Srikanth N.
Année de parution : 2017.
Mots-clés : celestial gravitation, clean environment-friendly energy source, deterministic factor, Energy conversion, Generators, hydraulic turbines, hydroelectric generators, kinetic energy, Maximum power point trackers, MPP tracking, MPPT, ORB method, P&O method, Reliability, TECS, Tidal Energy Conversion System, TSR method, Wind turbines.
Type de document : Article de colloque.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Structural Dynamic Analysis of a Tidal Current Turbine Using Geometrically Exact Beam Theory

Résumé : This paper presents a numerical study of the dynamic performance of a vertical axis tidal current turbine. First, we introduce the geometrically exact beam theory along with its numerical implementation the geometric exact beam theory (GEBT), which are used for structural modeling. We also briefly review the variational-asymptotic beam sectional analysis (VABS) theory and discrete vortex method with free-wake structure (DVM-UBC), which provide the one-dimensional (1D) constitutive model for the beam structures and the hydrodynamic forces, respectively. Then, we validate the current model with results obtained by ANSYS using three-dimensional (3D) solid elements and good agreements are observed. We investigate the dynamic performance of the tidal current turbine including modal behavior and transient dynamic performance under hydrodynamic loads. Finally, based on the results in the global dynamic analysis, we study the local stress distributions at the joint between blade and arm by VABS. It is concluded that the proposed analysis method is accurate and efficient for tidal current turbine and has a potential for future applications to those made of composite materials.
Domaine de référence : EMR
Auteur Wang Qi, Zhang Pengkun, Li Ye
Année de parution : 2017.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Can a wind turbine learn to operate itself ? Evaluation of the potential of a heuristic, data-driven self-optimizing control system for a 5MW offshore wind turbine

Résumé : Larger and more expensive offshore wind turbines, subject to more complex loads, operating in larger wind farms, could substantially benefit from more advanced control strategies. Nonetheless, the wind industry is reluctant to adopt such advanced, more efficient solutions, since this is perceived linked to a lower reliability. Here, a relatively simple self-optimizing control strategy, capable to “learn” (data-driven) which is the optimum control strategy depending on the objective defined, is presented. It is proved that it “re-discovers”, model-free, the optimum strategy adopted by commercial wind turbine in region 2. This methodology has the potential to achieve advanced control performance without compromising its simplicity and reliability.
Domaine de référence : EMR
Auteur Gueorguiev Iordanov Stefan, Collu Maurizio, Cao Yi
Année de parution : 2017.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Method of construction, assembly, and launch of a floating wind turbine platform

Résumé : A method of constructing and assembling a floating wind turbine platform includes constructing pre-stressed concrete sections of a floating wind turbine platform base, assembling the floating wind turbine platform base sections to form the base at a first location in a floating wind turbine platform assembly area, and moving the base to a second location in the floating wind turbine platform assembly area. Pre-stressed concrete sections of floating wind turbine platform columns are constructed, and the column sections are assembled to form a center column and a plurality of outer columns on the base to define a hull at the second location in the floating wind turbine platform assembly area. The hull is then moved to a third location in the floating wind turbine platform assembly area. Secondary structures are mounted on and within the hull, and the hull is moved to a fourth location in the floating wind turbine platform assembly area. A wind turbine tower is constructed on the center column, and a wind turbine is mounted on the wind turbine tower, thus defining the floating wind turbine platform. The floating wind turbine platform is then moved to a launch platform in a fifth location and launched into a body of water.
Domaine de référence : EMR
Année de parution : 2016.
Type de document : Brevet.
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Offshore deployable floating wind turbine system and method

Résumé : A method and system for installing a site-deployable wind turbine offshore. The wind turbine can be substantially assembled onshore and includes a floating structure and a tower that is extendable at the installation site. A pivoting system can be configured to couple the wind turbine and turbine blades to the extendable tower in an onsite deployable configuration. After the wind turbine is delivered to an offshore location, the wind turbine is deployed and the extendable base and pivoting system can be made to deploy the wind turbine and turbine blades into functional positions such that the wind turbine can begin generating electricity.
Domaine de référence : EMR
Année de parution : 2016.
Type de document : Brevet.
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Comparisons of the dynamical characteristics of a semi-submersible floating offshore wind turbine based on two different blade concepts

Résumé : Scaled model tests are important for the development and validation of floating offshore wind turbines. However, it has been found that Reynolds number dissimilitude between scales deteriorates the aerodynamic performance of floating offshore wind turbines when using model test investigation methodologies. To overcome this challenge, a semi-submersible floating offshore wind turbine model test with two different solutions, namely a geometrically matched blade model and a performance-matched blade model, was conducted in a wind/wave basin. Subsequently, a series of comparisons of the dynamical characteristics of these two models were made to clarify the respective validity of the two models and provide references for future floating offshore wind turbine model optimization. It is found that both model methods are capable of reflecting the essential dynamical characteristics but there are some differences in system eigenfrequencies and response amplitudes. Compared with the geometrically matched blade model, the performance-matched blade model has enhanced aerodynamic performance. Nevertheless, the overweight blades within the performance-matched blade model yields inevitable discrepancies compared with the original design.
Domaine de référence : EMR
Auteur Chen Jiahao, Hu Zhiqiang, Wan Decheng, Xiao Qing
Année de parution : 2018.
Mots-clés : Geometrically matched blade, Model test, Performance-matched blade, Reynolds number, Semi-submersible floating wind turbine.
Type de document : Article de revue.
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A comparative study of different methods for predicting the long-term extreme structural responses of the combined wind and wave energy concept semisubmersible wind energy and flap-type wave energy converter

Résumé : The combined wind and wave concept semisubmersible wind energy and flap-type wave energy converter was developed in the EU FP7 project MARINA Platform. It consists of a four-column semisubmersible with a 5-MW wind turbine placed on top of the central column and three flap-type wave energy converters on top of three pontoons that connect the four columns. Numerical and experimental studies have been performed to demonstrate the functionality and the survivability of the combined concept. In extreme conditions, both wind turbine and wave energy converters are set in a protection mode which reduces the dynamic loads and responses. In this article, different methods for predicting long-term (50-year) extreme responses considering the wind and wave conditions at two given European offshore sites are carried out, and structural response quantities are calculated, compared and presented. The full long-term analysis was performed and regarded as the reference method, and the corresponding results are compared with the modified environmental contour method and the environmental contour method. The response quantities studied here are the axial forces and bending moments of the semisubmersible wind energy and flap-type wave energy converter, including those of the wind turbine (blade, shaft and tower), arms of the flap-type wave energy converters and mooring lines, as well as the platform motion in 6 degrees of freedom. The extreme responses that are dominated by the aerodynamic loadings are effectively calculated either by the full long-term analysis or the modified environmental contour method. Compared to the full long-term analysis, the environmental contour method gives an under-prediction of the long-term extreme responses of quantities related to the wind turbine (e.g. internal loads of blades and tower). For the extreme responses that are dominated by the hydrodynamic loadings, all the three methods provide similar results.
Domaine de référence : EMR
Auteur Li Qinyuan, Michailides Constantine, Gao Zhen, Moan Torgeir
Année de parution : 2018.
Type de document : Article de revue.
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Performance and reliability testing of an active mooring system for peak load reduction

Résumé : Offshore renewable energy systems are generally required to operate in exposed offshore locations for long deployment periods at low cost. This requires innovative new mooring system solutions to go beyond the existing offshore industry designs. A number of novel mooring systems have recently been proposed which decouple mooring line compliance and minimum breaking load, offering multiple benefits to designers. Demonstrating reliability for such highly novel systems where standards do not yet exist is a common problem both for mooring systems specifically and in offshore renewable applications generally. A performance and reliability test method is proposed here and is applied to a novel mooring system, the Intelligent Active Mooring System. The line stiffness and damping properties of Intelligent Active Mooring System can be optimised to the prevailing metocean conditions without compromising minimum breaking load; the pre-tension is also adjustable for tidal range compensation or for service access. The article presents the results of a feasibility study for Intelligent Active Mooring System including detailed, large-scale physical performance tests that demonstrate load reductions under normal operating and extreme sea state conditions. The rationale and findings for an accelerated reliability test regime that quantifies the ultimate load capacity of the component and gives insight into the governing failure modes are also presented. The presented test approach provides assurance for the overall system integrity.
Domaine de référence : EMR
Auteur Luxmoore Jamie F., Thies Philipp R., Grey Simon, Newsam David, Johanning Lars
Année de parution : 2018.
Type de document : Article de revue.
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Wind Energy Research : State-of-the-Art and Future Research Directions

Résumé : This paper reports the findings from the 2016 Wind Energy Research Workshop held in Lowell, MA. The workshop examined the state-of-the-art in wind energy research within the following three core topic areas: (A) Wind Turbine Design and Manufacturing including: blades, towers/foundations and nacelle, (B) Wind Farm Development including: offshore installations/siting, flow characterization and loads/waves/wind characterization, and (C) Wind Farm Operations including: controls, power production, wind farms, sensing, diagnostics, testing, structural health monitoring, reliability, energy storage, the grid and power transmission. Research challenges and future directions were discussed and are reported for each sub-topic area.
Domaine de référence : EMR
Auteur Willis D. J., Niezrecki C., Kuchma D., Hines E., Arwade S., Barthelmie R. J., DiPaola M., Drane P. J., Hansen C. J., Inalpolat M., Mack J. H., Myers A. T., Rotea M.
Année de parution : 2018.
Mots-clés : Design, List of Abbreviations, Manufacturing, Operations, Resource, Wind Energy.
Type de document : Article de revue.
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First in situ evidence of wakes in the far field behind offshore wind farms

Résumé : More than 12 GW of offshore wind turbines are currently in operation in European waters. To optimise the use of the marine areas, wind farms are typically clustered in units of several hundred turbines. Understanding wakes of wind farms, which is the region of momentum and energy deficit downwind, is important for optimising the wind farm layouts and operation to minimize costs. While in most weather situations (unstable atmospheric stratification), the wakes of wind turbines are only a local effect within the wind farm, satellite imagery reveals wind-farm wakes to be several tens of kilometres in length under certain conditions (stable atmospheric stratification), which is also predicted by numerical models. The first direct in situ measurements of the existence and shape of large wind farm wakes by a specially equipped research aircraft in 2016 and 2017 confirm wake lengths of more than tens of kilometres under stable atmospheric conditions, with maximum wind speed deficits of 40%, and enhanced turbulence. These measurements were the first step in a large research project to describe and understand the physics of large offshore wakes using direct measurements, together with the assessment of satellite imagery and models.
Domaine de référence : EMR
Auteur Platis Andreas, Siedersleben Simon K., Bange Jens, Lampert Astrid, Bärfuss Konrad, Hankers Rudolf, Cañadillas Beatriz, Foreman Richard, Schulz-Stellenfleth Johannes, Djath Bughsin, Neumann Thomas, Emeis Stefan
Année de parution : 2018.
Type de document : Article de revue.
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Design and Analysis of a Marine Current Turbine

Résumé : Ocean stores a huge amount of energy and ocean current energy can be a viable source in future. In this article, an axial marine current turbine has been optimized to enhance its power coefficient through numerical modeling. The blade pitch-angle and number of blades are the design parameters chosen for the analysis to find the optimal design. A commercial code for CFD simulations with in-house optimization code was used for the analysis. It was found that, changing the blade pitch-angle and reducing the number of blades can improve the turbine’s coefficient of power. This is due to increase in lift and reduction of losses caused by turbulence near the downstream of the turbine. The article presents flow-simulation difficulties and characteristic curves to identify the differences between the actual and optimized turbine. The detailed flow physics is discussed and pictured in the post processed plots.
Domaine de référence : EMR
Auteur Karthikeyan T., Avital E. J., Venkatesan N., Samad A.
Année de parution : 2017.
Type de document : Article de revue.
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Offshore Mechanics : Structural and Fluid Dynamics for Recent Applications

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

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

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

Résumé : Over the past few decades, wind energy has emerged as an alternative to conventional power generation that is economical, environmentally friendly and, importantly, renewable. Specifically, offshore wind energy is being considered by a number of countries to harness the stronger and more consistent wind resource compared to that over land. To meet the projected “20% energy from wind by 2030” scenario that was announced in 2006, 54 GW of added wind energy capacity need to come from offshore according to a National Renewable Energy Laboratory (NREL) study. In this study, we discuss the development of a semi-submersible floating offshore platform with a catenary mooring system to support a very large 13.2-MW wind turbine with 100-m blades. An iterative design process is applied to baseline models with Froude scaling in order to achieve preliminary static stability. Structural dynamic analyses are performed to investigate the performance of the new model using a finite element method approach for the tower and a boundary integral equation (panel) method for the platform. The steady-state response of the system under uniform wind and regular waves is first studied to evaluate the performance of the integrated system. Response amplitude operators (RAOs) are computed in the time domain using white-noise wave excitation; this serves to highlight nonlinear, as well as dynamic characteristics of the system. Finally, selected design load cases (DLCs) and the stochastic dynamic response of the system are studied to assess the global performance for sea states defined by wind fields with turbulence and long-crested irregular waves.
Domaine de référence : EMR
Auteur Liu Jinsong, Thomas Edwin, Manuel Lance, Griffith D. Todd, Ruehl Kelley M., Barone Matthew
Année de parution : 2018.
Mots-clés : design load, offshore wind turbine, response amplitude operator (RAO), stochastic dynamics.
Type de document : Article de revue.
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Assessment of Energy Use and Elimination of Co2 Emissions in the Life Cycle of an Offshore Wind Power Plant Farm

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

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

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

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

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

Résumé : An underwater frame supporting a plurality of tidal turbines. The frame is tethered to a seabed fixing such that the frame and tidal turbines are positioned downstream of tidal flow. The frame is steerable so as to increase energy capture from said turbines by exposing them to undisturbed tidal flow.
Domaine de référence : EMR
Auteur ARMSTRONG John Richard Carew, TODMAN Michael Torr
Année de parution : 2017.
Type de document : Brevet.
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Plus de références EMR


• Biocorrosion icone-flux-rss

Sulphate-reducing bacteria (SRB) in the Yangtze Estuary sediments : Abundance, distribution and implications for the bioavailibility of metals

Résumé : Ubiquitous in the aquatic environment, sulphate-reducing bacteria (SRB) are considered one of the dominant microorganisms involved in the degradation of sulphate. This study focused on the spatial and temporal distributions of SRB in the Scirpus triquter rhizosphere sediments with a comparison to non-rhizosphere sediments and evaluated the implication of SRB to the bioavailability of metals in the Yangtze Estuary. The results showed that taking dsrB as the target gene, SRB abundances in rhizosphere sediments were significantly higher than those in non-rhizosphere sediments (P<0.01). SRB abundances were relatively higher in April and January than other seasons. Moreover, redundancy discriminate analysis (RDA) results indicated that sulphate, pH and TOC were the major environmental factors affecting the SRB abundance in rhizosphere sediments. The concentrations of most metals were significantly related to SRB abundance, and sulphide concentrations showed a significantly positive correlation to metal concentrations, indicating metal sulphide/metal associated sulphide could be regulated by SRB. Furthermore, electron microscope analysis found that nano-sized metal sulphide particles were ubiquitous in rhizosphere sediments and could be further taken up by plants. This study provides new insights into the immobilization and removal of heavy metals and the ecological value of the sulphate-reducing bacteria in the Yangtze Estuary.
Domaine de référence : Biocorrosion
Auteur Niu Zuo-shun, Pan Hui, Guo Xing-pan, Lu Da-pei, Feng Jing-nan, Chen Yu-ru, Tou Fei-yun, Liu Min, Yang Yi
Année de parution : 2018.
Mots-clés : Metal, Nanoparticle, Rhizosphere sediment, Sulphate-reducing bacteria (SRB), Sulphide.
Type de document : Article de revue.
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Corrosion of Q235 carbon steel influenced by the introduction of aerogenic and aerobic bacteria

Résumé : Corrosion of carbon steel is investigated in the presence of Synechococcus sp. (S. sp., an aerogenic strain) with or without the coexistence of Pseudoalteromonas sp. (P. sp., an aerobic strain). Results of electrochemical and weight loss measurements suggest that the corrosion of carbon steel is continuous in S. sp. containing media while it is inhibited initially and accelerated finally in the coexistence of S. sp. and P. sp. This variation in corrosion rate is believed to be closely related to the difference in the growth and metabolism of two strains in different media. In media containing S. sp. alone, the slow reproduction of S. sp. leads to the relatively stable dissolved oxygen (DO) concentration and the continuous corrosion. In the case of S. sp. + P. sp., P. sp. consume DO and form protective biofilm at the initial stage, and then the death of P. sp. and the rapid reproduction of S. sp. cause the increase of DO concentration and the formation of porous corrosion products, leading to the change of corrosion rate.
Domaine de référence : Biocorrosion
Auteur Tan Faqi, Wu Jiajia, Zhang Dun, Li Ee, Sun Yan, Gao Jieyan
Année de parution : 0.
Mots-clés : carbon steel, microbiologically influenced corrosion, Pseudoalteromonas sp, Synechococcus sp.
Type de document : Article de revue.
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Organic Corrosion Inhibitors | IntechOpen

Résumé : null
Domaine de référence : Biocorrosion
Année de parution : 0.
Type de document : Page Web.
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Progress on Influence of Cathodic Polarization on Sulfate-reducing Bacteria Induced Corrosion, Progress on Influence of Cathodic Polarization on Sulfate-reducing Bacteria Induced Corrosion

Domaine de référence : Biocorrosion
Auteur Guan Fang, Zhai Xiaofan, Duan Jizhou, Hou Baorong, Guan Fang, Zhai Xiaofan, Duan Jizhou, Hou Baorong
Année de parution : 2018.
Type de document : Article de revue.
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Biocorrosion of mild steel and copper used in cooling tower water and its control

Résumé : The present study describes the biocorrosion of mild steel (MS1010) and pure copper (Cu) in cooling water environments (both field and lab study). Electrochemical and surface analyses of both metals were carried out to confirm the corrosion susceptibility in the presence of bacteria and inhibitor. Surface analysis of the MS and Cu coupons revealed that biofilm was developed with increasing exposure time in the field study. In the lab study, accumulation of extracellular polymeric substance over the metal surface was noticed and led to the severe pitting type of corrosion on both metal surfaces. Besides, the anti-corrosive study was carried out using the combinations of commercial corrosion inhibitor (S7653—10 ppm) with biocide (F5100—5 ppm), and the results reveal that the corrosion rate of MS and Cu was highly reduced to 0.0281 and 0.0021 mm/year (inhibitor system) than 0.1589 and 0.0177 mm/year (control system). Inhibition efficiency for both metals in the presence of inhibitor with biocide was found as 82 and 88% for MS and Cu, respectively. The present study concluded that MS was very susceptible to biocorrosion, compared to copper metal in cooling water environment. Further, the combination of the both inhibitor and biocide was effectively inhibiting the biocorrosion which was due to its antibacterial and anti-corrosive properties.
Domaine de référence : Biocorrosion
Auteur Li Xiao Lei, Narenkumar Jayaraman, Rajasekar Aruliah, Ting Yen-Peng
Année de parution : 2018.
Type de document : Article de revue.
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Method for monitoring microbiologically induced corrosion on metal surfaces

Résumé : A method for monitoring microbiologically induced corrosion on metal surfaces in contact with a fluid. The method comprises adding to the fluid a silanol compound or silanol compound precursor having a group detectible by ultraviolet spectrophotometry or fluorescence spectroscopy, or which is isotopically enriched.
Domaine de référence : Biocorrosion
Année de parution : 2016.
Type de document : Brevet.
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Uniform and pitting corrosion of carbon steel by Shewanella oneidensis MR-1 under nitrate-reducing conditions.

Résumé : Despite observations of steel corrosion in nitrate-reducing environments, processes of nitrate-dependent microbially influenced corrosion (MIC) remain poorly understood and difficult to identify. We evaluated carbon steel corrosion by Shewanella oneidensis MR-1 under nitrate-reducing conditions using a split-chamber/zero resistance ammetry (ZRA) technique. This approach entails deployment of two metal (carbon steel 1018 in this case) electrodes into separate chambers of an electrochemical split-chamber unit, where the microbiology or chemistry of the chambers can be manipulated. This approach mimics the conditions of heterogeneous metal coverage that can lead to uniform and pitting corrosion. Current between working electrodes WE1 and WE2 can be used to determine rates, mechanisms, and we now show, extents of corrosion. When S. oneidensis was incubated in the WE1 chamber with lactate under nitrate-reducing conditions, nitrite transiently accumulated, and electron transfer occurred from WE2 to WE1 as long as nitrite was present. Nitrite in the WE1 chamber (without S. oneidensis) induced electron transfer in the same direction, indicating that nitrite cathodically protected WE1 and accelerated corrosion of WE2. When S. oneidensis was incubated in the WE1 chamber without electron donor, nitrate reduction proceeded and electron transfer from WE2 to WE1 also occurred, indicating that the microorganism could use the carbon steel electrode as an electron donor for nitrate reduction. Our results indicate that under nitrate-reducing conditions, uniform and pitting carbon steel corrosion can occur due to nitrite accumulation and use of steel-Fe(0) as an electron donor, but conditions of sustained nitrite accumulation can lead to more aggressive corrosive conditions. IMPORTANCE Microbially influenced corrosion (MIC) causes damage to metals and metal alloys that is estimated to cost over $100 million/year in the US to prevent, mitigate, and repair. While MIC occurs in a variety of settings and by a variety of organisms, the mechanisms by which microorganisms cause this damage remain unclear. Steel pipe and equipment may be exposed to nitrate, especially in oil and gas production, where that compound is used for corrosion and “souring” control. In this paper, we show uniform and pitting MIC under nitrate-reducing conditions, and that a major mechanism by which it occurs is via heterogeneous cathodic protection of metal surfaces by nitrite, as well as by microbial oxidation of steel-Fe(0).
Domaine de référence : Biocorrosion
Auteur Miller Robert B., Lawson Kenton, Sadek Anwar, Monty Chelsea N., Senko John M.
Année de parution : 2018.
Type de document : Article de revue.
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Anaerobic microbiologically influenced corrosion mechanisms interpreted using bioenergetics and bioelectrochemistry : A review

Résumé : Microbiologically influenced corrosion (MIC) is a major cause of corrosion damages, facility failures, and financial losses, making MIC an important research topic. Due to complex microbiological activities and a lack of deep understanding of the interactions between biofilms and metal surfaces, MIC occurrences and mechanisms are difficult to predict and interpret. Many theories and mechanisms have been proposed to explain MIC. In this review, the mechanisms of MIC are discussed using bioenergetics, microbial respiration types, and biofilm extracellular electron transfer (EET). Two main MIC types, namely EET-MIC and metabolite MIC (M-MIC), are discussed. This brief review provides a state of the art insight into MIC mechanisms and it helps the diagnosis and prediction of occurrences of MIC under anaerobic conditions in the oil and gas industry.
Domaine de référence : Biocorrosion
Auteur Li Yingchao, Xu Dake, Chen Changfeng, Li Xiaogang, Jia Ru, Zhang Dawei, Sand Wolfgang, Wang Fuhui, Gu Tingyue
Année de parution : 2018.
Mots-clés : Bioelectrochemistry, Bioenergetics, Biofilm, Extracellular electron transfer (EET), MIC classification, Microbiologically influenced corrosion.
Type de document : Article de revue.
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Self-healing and Bacteria Resistant Coating Materials for Various Substrates

Résumé : The present invention provides a coating composition and a method of imparting self-healing, anti-microbial and anti-fouling properties onto a substrate at ambient temperature without external intervention. The coating composition comprises a product of an in-situ polymerization mixture comprising diisocyanate, polyol and saccharide. The polyol is a polyester or a polyether.
Domaine de référence : Biocorrosion
Auteur Tao Hong, LI Siyue, NG Yin Ming, Jin Qiu
Année de parution : 2018.
Mots-clés : coating, composition, invention, present, self.
Type de document : Brevet.
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Corrosion behavior of the chitosan‑zinc composite films in sulfate-reducing bacteria

Résumé : Sulfate-reducing bacteria (SRB) are one of the chief inducers of microbiologically influenced corrosion in marine environment. In our previous work, a novel chitosan‑zinc film was electrodeposited and found to be effectively antibacterial, so research on the corrosion behavior of chitosan‑zinc films in SRB medium is highly significant for estimating the films to be applied in real-sea environment. In this paper, detection of SRB metabolism, electrochemical methods and surface analyses were performed to clarify the corrosion behavior. During 6 d exposure in SRB, obvious inhibition on SRB growth and metabolism were found by monitoring the environment corrosive factors. By calculating the corrosion rate and analyzing surface morphologies, chitosan‑zinc films showed relatively high corrosion resistance. After exposure, biofilm together with corrosion products formed on zinc film, while corrosion product layer with little bacteria attached on chitosan‑zinc composite film. Further electrochemical results showed that the addition of chitosan did not change the anodic and cathodic behavior of the films, but enhanced the corrosion resistance by reducing the corrosive ability SRB medium, inhibiting bacteria attachment and raising the films' electric conductibility to a certain extent.
Domaine de référence : Biocorrosion
Auteur Zhai Xiaofan, Li Ke, Guan Fang, Sun Congtao, Duan Jizhou, Hou Baorong
Année de parution : 2018.
Mots-clés : Antibacterial, Chitosan‑zinc composite films, Corrosion resistance, Electrochemical analysis, Sulfate-reducing bacteria.
Type de document : Article de revue.
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Study of corrosion behavior of copper in 3.5 wt.% NaCl solution containing extracellular polymeric substances of an aerotolerant sulphate-reducing bacteria

Résumé : Extracellular polymeric substances (EPS) of an aerotolerant sulphate-reducing bacteria were extracted, and they contained mainly polysaccharides and proteins. Effects of EPS on corrosion behavior of copper were investigated through electrochemical methods and surface analysis techniques in 3.5 wt.% NaCl solution under aerobic condition. Results indicated that after a short-period immersion, EPS inhibit copper corrosion, and their inhibition effect decreases with increasing EPS concentration. For long-term immersion, copper corrosion is promoted due to the destruction of the protective Cu2O film by EPS.
Domaine de référence : Biocorrosion
Auteur Chen Shiqiang, Zhang Dun
Année de parution : 2018.
Mots-clés : A. Copper, B. EIS, B. FT-IR spectroscopy, B. SEM, C. Microbiologically influenced corrosion.
Type de document : Article de revue.
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Deployment of Pre-Industrial Autonomous Microbe Sensor in Saudi Arabia’s Injection Seawater System

Résumé : Microbial growth in water injection systems can lead to many problems, including biofouling, water quality deterioration, injectivity loss, microbial corrosion, and reservoir formation damage. Monitoring of microbial activities is required in any mitigation strategy, enabling operators to apply and adjust countermeasures properly and in due time. In this study, the pre-industrial autonomous microbe sensor (AMS) was constructed with technical improvements from the prototype for increased sensitivity, durability, robustness, and maintainability. The pre-industrial AMS was lab validated, field proven, and deployed at critical locations of seawater injection network for automated detection of microorganisms under the Saudi Arabia’s harsh environment. An excellent correlation between AMS measurement data (fluorescence count) and actual count of microbial cell number under microscope was established (coefficient of determination, R2 > 0.99) for converting AMS fluorescence count to cell numbers (cell mL-1) in the injection seawater. The pre-industrial AMS only required monthly maintenance with solutions refill, and was able to cope with hot summer months even without protection in an air-conditioned shelter. The study team recommended wider deployment of the online AMS for real-time monitoring of bacteria numbers in the various strategic locations in Saudi Aramco’s complex seawater injection network, as an integral component of pipeline corrosion and leak mitigation program.
Domaine de référence : Biocorrosion
Auteur Al-Moniee Mohammed A., Zhu Xiangyang, Markfoged Rikke, Al-Wadei Aabdullah H., Pedersen Poul L., Tuxen Anders K., Al-Nuwaiser Fuad I., Tang Lone, Roesen Tinna Staghøj, Lundgaard Thomas
Année de parution : 2018.
Type de document : Article de revue.
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Confined Flow : Consequences and Implications for Bacteria and Biofilms

Résumé : Bacteria overwhelmingly live in geometrically confined habitats that feature small pores or cavities, narrow channels, or nearby interfaces. Fluid flows through these confined habitats are ubiquitous in both natural and artificial environments colonized by bacteria. Moreover, these flows occur on timeand length scales comparable to those associated with motility of bacteria and with the formation and growth of biofilms, which are surface-associated communities that house the vast majority of bacteria and protect them from host and environmental stresses. This review describes the emerging understanding of how flow near surfaces and within channels and pores alters physical processes that control how bacteria disperse, attach to surfaces, and form biofilms. This understanding will inform the development and deployment of technologies for drug delivery, water treatment, and antifouling coatings and guide the structuring of bacterial consortia for production of chemicals and pharmaceuticals. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering Volume 9 is June 7, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Domaine de référence : Biocorrosion
Auteur Conrad Jacinta C., Poling-Skutvik Ryan
Année de parution : 2018.
Type de document : Article de revue.
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Failure Analysis of Pitted Copper Pipes Used in Underground Water and Preventive Measures

Résumé : This study performed an experiment on the causes of pitting corrosion in a copper tubing used for a sprinkler system. Corrosion products of a copper tubing that sustained pitting corrosion were collected and cultured in Culture medium [Luria–Bertani, Brain heart infusion, Tryptic soy broth (TSB), R2A]. Four types of bacteria were found through identification: Micrococcus luteus sp (species)., Staphylococcus sp., Sphingomonas sp., and Bacillus sp. The copper toxicity test was performed for each microorganism. Among the four microorganisms, Micrococcus luteus sp. showed good growth in the environment containing copper ions. On the immersion test, changes in pH and Optical density were measured; On the inductively coupled plasma optical emission spectrometry test, the copper concentration of each culture medium was measured. The surface of each copper sample was observed using a scanning electron microscope. The corrosion potential of a copper sample, after 48 h exposure of the TSB medium containing Micrococcus luteus sp., was measured using a potentiodynamic polarization experiment. The next experiment was conducted to prevent microbial corrosion by suppressing the growth of microorganisms. Six 30 ml TSB culture media with controlled pH value of 4, 5, 6, 7, 8, and 9 through HCl and NaOH were manufactured. Then the microorganisms were cultured in 37 °C 133 rpm, of which the growth status was checked every 24 h for 3 days. It was found that microorganisms did not grow on culture media with the pH value of 6 and lower. The same experiment conducted on culture media controlled with acetic acid, nitric acid, and sulfuric acid, also showed no growth of microorganisms on media with pH value of 6 and lower. Six 5 ml TSB culture media each containing 0.5, 0.25, 0.125, 0.0625, 0.0312%, and 0.0156% NaOCl and NaOBr as germicides were manufactured. 0.01 μl of microorganisms were inoculated on the media and cultured in 37 °C for 48 h. It was found that microorganisms did not grow in media with NaOCl and NaOBr concentration of 0.0625% and higher. Therefore, it can be suggested that in environments with pH value of 6 or lower, or NaOCl and NaOBr concentration of higher than 0.0625% suppresses microbial growth, thereby preventing microbial corrosion.
Domaine de référence : Biocorrosion
Auteur Nam Gi-ho, Lee Jong-kwon, Kim Kyung-ja
Année de parution : 2018.
Type de document : Article de revue.
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Copper corrosion monitoring by electrical resistance probes in anoxic groundwater environment in the presence and absence of sulfate reducing bacteria

Résumé : In this study the results from corrosion monitoring of copper in anoxic simulated ground water in the presence and absence of sulfate-reducing bacteria (SRB) enriched from the planned disposal site of high level nuclear waste are presented. Copper electric resistance (ER) probes were applied as a physical tool for monitoring corrosion of copper disposal canister. The results are compared to those obtained by linear polarization resistance (LPR) measurements, conducted for parallel OFP-Cu specimens during the experiments, and by weight loss measurements. ER probe method was the most sensitive to corrosion and gave the most conservative estimation of the lifetime of copper. Independently whether the environment was abiotic or biotic, ER probe data showed relatively similar trends to the results from LPR and weight loss measurements. Difference in sensitivity of the methods arises from different ability to detect pitting corrosion and microbial activities on specimen surfaces in the two environments.
Domaine de référence : Biocorrosion
Auteur Marja-aho Maija, Rajala Pauliina, Huttunen-Saarivirta Elina, Legat Andraž, Kranjc Andrej, Kosec Tadeja, Carpén Leena
Année de parution : 2018.
Mots-clés : Copper, Corrosion monitoring, Groundwater, Microbiologically influenced corrosion, Nuclear waste disposal.
Type de document : Article de revue.
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Oilfield Microbiology : Molecular Microbiology Techniques Used During a Biocide Evaluation

Résumé : Biocide chemicals are an essential control in the oil and gas industry. From drinking water to hydrocarbon production streams, it is necessary to use the correct chemical, at the correct dose to prevent uncontrolled microbiological activity. The objective of this review is to discuss an example of a biocide evaluation that tested seven (7) different biocide chemicals (from the same chemical vendor) against planktonic and sessile microbial populations by both traditional and molecular microbiological monitoring techniques. The methods used in the biocide evaluation were in accordance to internationally recognised standards; NACE TM0194-2014 ‘Field Monitoring of Bacterial Growth in Oil and Gas Systems’ and NACE TM0212-2012 ‘Detection, Testing, and Evaluation of Microbiologically Influenced Corrosion on Internal Surfaces of Pipelines’. The procedure stated that 7 biocides at 2 concentrations (500ppm and 1000ppm of product) were to be tested against bacterial populations (planktonic and sessile), in relation to appropriate water chemistry and microbial consortia. The microbiological techniques used to determine the biocide efficacy were; traditional Most Probable Number (MPN) bacterial enumeration of; Sulphate Reducing Bacteria (SRB), General Heterotrophic Bacteria (GHB) and Acid-Producing General Heterotrophic Bacteria (APGHB), Quantitative Polymerase Chain Reaction (qPCR) with pre-selected primers for SRB, Sulphate Reducing Archaea (SRA), and lastly, Next Generation Sequencing (NGS). The results from the microbiological techniques allowed for an evaluation by ranking each biocide chemical in comparison to the total test group of chemicals, against untreated controls. Performance was based on the reduction of microbiological populations from the untreated control populations and greater microbiological community detail was achieved through interpretation of the molecular techniques data. The inclusion of molecular microbiological monitoring techniques to biocide evaluations is a novel approach to understanding the direct impact of biocide chemicals in greater detail. In turn, this approach will provide knowledge and valuable information for chemical addition optimisation and cost saving.
Domaine de référence : Biocorrosion
Auteur Bennet Douglas, Hoffmann Heike
Année de parution : 2018.
Type de document : Article de colloque.
Source : Offshore Technology Conference
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Antimicrobial Cu-bearing 2205 duplex stainless steel against MIC by nitrate reducing Pseudomonas aeruginosa biofilm

Résumé : In industrial and clinical settings, microbiologically influenced corrosion (MIC), also known as biocorrosion, is a major problem associated with materials degradation and infection. To mitigate biofilms, a Cu-bearing 2205 duplex stainless steel (2205-Cu DSS) was created by researchers to utilize the antimicrobial ability of copper. In this study, nitrate reducing Pseudomonas aeruginosa biofilm was grown as a nitrate reducing bacterium to investigate the antimicrobial efficacy and the MIC inhibition efficacy of 2205-Cu DSS under anaerobic condition. The results showed that both biofilm sessile cell count and electrochemically-measured corrosion rate were reduced compared with the 2205 duplex stainless steel (2205 DSS) control.
Domaine de référence : Biocorrosion
Auteur Liu Jialin, Jia Ru, Zhou Enze, Zhao Ying, Dou Wenwen, Xu Dake, Yang Ke, Gu Tingyue
Année de parution : 2018.
Mots-clés : 2205-Cu duplex stainless steel, Antimicrobial, Biofilm, Microbiologically influenced corrosion.
Type de document : Article de revue.
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Biocorrosion of mild steel and copper used in cooling tower water and its control

Résumé : The present study describes the biocorrosion of mild steel (MS1010) and pure copper (Cu) in cooling water environments (both field and lab study). Electrochemical and surface analyses of both metals were carried out to confirm the corrosion susceptibility in the presence of bacteria and inhibitor. Surface analysis of the MS and Cu coupons revealed that biofilm was developed with increasing exposure time in the field study. In the lab study, accumulation of extracellular polymeric substance over the metal surface was noticed and led to the severe pitting type of corrosion on both metal surfaces. Besides, the anti-corrosive study was carried out using the combinations of commercial corrosion inhibitor (S7653—10 ppm) with biocide (F5100—5 ppm), and the results reveal that the corrosion rate of MS and Cu was highly reduced to 0.0281 and 0.0021 mm/year (inhibitor system) than 0.1589 and 0.0177 mm/year (control system). Inhibition efficiency for both metals in the presence of inhibitor with biocide was found as 82 and 88% for MS and Cu, respectively. The present study concluded that MS was very susceptible to biocorrosion, compared to copper metal in cooling water environment. Further, the combination of the both inhibitor and biocide was effectively inhibiting the biocorrosion which was due to its antibacterial and anti-corrosive properties.
Domaine de référence : Biocorrosion
Auteur Li Xiao Lei, Narenkumar Jayaraman, Rajasekar Aruliah, Ting Yen-Peng
Année de parution : 2018.
Type de document : Article de revue.
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Developing an ecofriendly approach to reduce the use of biocides for preventing Microbial Induced Corrosion

Résumé : Sulfate Reducing Bacteria (SRB) cause significant damage to marine oil pipelines necessitating the use of biocides for reducing the Microbial Induced Corrosion (MIC) and potential for great environmental harm. Currently, oil companies pump frequent batches of biocides to these under water pipelines without proper quantification of the bacterial population. This is primarily because the existing method for quantifying the bacterial population in a sample is not very effecient, as it can take up to 2 weeks to obtain the results. Our team has focused on developing an eco-friendly approach to limit the use of these biocides, which are used for targeting the SRB. SRB require high salt and low oxygen so first we genetically engineered a strain of bacteria that would report the osmolarity in oil pipelines, thus act as a biosensor for salt concentrations. The ratio of salinity in the seawater flowing in versus the seawater flowing out of the well will be used to estimate SRB populations in the pipelines, thus limiting the amount of biocides added in times of high Microbial counts.
Domaine de référence : Biocorrosion
Auteur Rasool Saad
Année de parution : 2018.
Type de document : Article de revue.
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Chitosanbased nanocomposite for the inhibition of sulfate reducing bacteria : Towards “green” biocides for microbial influenced corrosion

Résumé : Microbial Influenced Corrosion (MIC) is a process influenced by various microorganisms especially by sulfate reducing bacteria (SRB) which affects the kinetics of corrosion procedure under anaerobic conditions. About 20% of the annual corrosion damages of metals may be produced by microbial activities especially due to anaerobic corrosion influenced by SRB. MIC is the main contributor of corrosion problems and a leading cause of pipeline failure in oil and gas industries. SRBs are main microorganisms that can anaerobically generate sulfide species causing biocorrosion in the injection networks. Moreover, the produced H2S gas is toxic, corrosive, and responsible for a variety of environmental problems. Additionally, the presence of SRB can result in health and safety risks to workers due to sulfide production. In order to prevent this, oil-producing companies use high concentrations of biocides to disinfect the water and inhibit excessive biofilm formation caused mainly by (SRB). However, traditional biocides may be harmful to environment by forming harmful disinfection byproducts. Also the biocide treatment having other disadvantages like low efficiency against biofilms, release of disinfection byproducts and its high cost. Theses disadvantages can be solved by the use of green biocides including nanomaterials which has very low toxicity, environmental acceptability, safety and ease of use etc. Several nanomaterials have been utilized to inhibit the growth of different microorganisms and can be a possible alternative for controlling SRB biofilm and its corrosion. Here, we introduced an environmentally benign approach to use a green biocide; chitosan-ZnO nanocomposite against SRB induced MIC towards carbon steel. The nanoparticles of chitosan and ZnO were prepared independently and treated together to form the chitosan-ZnO nanocomposite. The nanocomposite was synthesized with different percentage of ZnO initial content and characterized by SEM, TEM, FTIR, TGA etc. The average size of chitosan nanoparticles were in between 40-60 nm and it clearly shows the distribution of ZnO NPs in the chitosan nanoparticles matrix. The particles in chitosan-ZnO nanocomposite were found with almost spherical morphology. The electrodes were made of carbon steel S150 was used for all the experiments. S150 carbon steel electrode of exposed area of 8 mm diameter used for the corrosion experiments after hot mounting process followed by polishing and grinding process. The electrodes were incubated with SRB containing media with and without nanocomposites and kept in a shaking incubator at 37° under inert atmosphere. The effect of the chitosan-ZnO nanocomposite on corrosion inhibition was studied by varying the concentrations of nanocomposites under optimized bacterial concentration and experimental conditions. The surface features and the elemental analysis of the biofilm and corrosion product were evaluated by SEM as well as XPS in different time intervals and compared with the control samples. The surface features of the corroded electrodes was investigated by SEM and profilometry after removing the corrosion product by using a simple chemical treatment procedure. The effect of chitosan-ZnO nanocomposite on corrosion behavior of carbon steel against SRB was investigated by electrochemical impedance spectroscopy, corrosion potential, polarization resistance and polarization curve measurements at different time intervals. It was found that the chitosan-ZnO nanocomposite inhibits the SRB biofilm formation and corrosion. The results of the electrochemical analysis showed that the chitosan-ZnO nanocomposite (10% ZnO content) at 250 ppm concentration having highest corrosion inhibition and can be used an effective corrosion inhibition agent against SRB induced MIC. References Wang, H. F., et al. Materials Chemistry and Physics 124, 791-794, (2010).Vanaei, H. R., et al. International Journal of Pressure Vessels and Piping 149, 43-54, (2017). Xu, D. et al. Engineering Failure Analysis 28, 149-159, (2013).
Domaine de référence : Biocorrosion
Auteur Pathath Abdul Rasheed, Jabbar Khadeeja Abdul, Mahmoud Dr Khaled
Année de parution : 2018.
Type de document : Article de revue.
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Efficient Inhibition of SulfateReducing Bacteria in Inject Sea Water by “Green” Chitosan/ZnO nanocomposite

Résumé : Oil producing companies utilize water injection as a common oil recovery method for decades, especially for offshore fields, where seawater is typically used as inject water. Due to the size and complexity of the injection system and the high salinity of the water (∼55,000 mg/L); several challenges are faced during this process including microbial growth, fouling and corrosion in the pipeline. Biofilms accelerate corrosion in a biologically conditioned metal–solution interface. Oil producing companies including those in Qatar use biocides to disinfect the water and inhibit biofilm formation caused mainly by sulfate reducing bacteria (SRB). However, traditional biocides may induce bacterial resistance and/or be detrimental to environment. In this study we synthesized chitosan/ZnO nanocomposite (CZNCs) and evaluated its antimicrobial activity against SRB biofilm in inject seawater. CZNCs showed stable behavior when exposed to higher salt concentrations of inject water. The inhibition of SRB activity was concentration-dependent and more than 73% and 43% inhibition of sulfate reduction and TOC removal, respectively, was observed at 250 μg/mL CZNCs at 10% initial ZnO loading. Scanning electron microscopy (SEM) coupled with lactate dehydrogenase (LDH) release assay indicated obvious damages to the cellular membrane which resulted in release of cytoplasmic materials from the bacterial cells. Significant decrease in concentration of EPS extracts was obtained. This work has demonstrated that the exposure of synthesized CZNCs could cause significant SRB anti-biofouling properties. This is the first ever study of antimicrobial potential of chitosan based biocides for SRB inhibition. We are confident that this work will make the scientific as well as the industrial communities to appreciate the application of nanomaterials based biocides. This is the first ever study of antimicrobial potential of any ENM generally, and chitosan based biocides, particularly, for SRB enriched biofilm inhibition. Taking into account tremendous interest to nanomaterials as antimicrobial agents, we anticipate a major impact from a much better material reported in his paper.
Domaine de référence : Biocorrosion
Auteur Rasool Kashif
Année de parution : 2018.
Type de document : Article de revue.
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Variations regularity of microorganisms and corrosion of cast iron in water distribution system

Résumé : Corrosion, one of the most common problems of metal pipe for water supply, generally leads to poor water quality, bacteria proliferation, water capacity decrease and other problems. As microorganisms affect corrosion by changing the characteristics of metal surface, the mechanism of microbial corrosion still remains unclear. The corrosion behavior of ductile cast iron is implemented in the dynamic flow and static conditions, in which variations of water quality and microbial community are analyzed in details. The results show that if the corrosion rate of ductile cast iron decreases, the corrosion of cast iron will result in a lower DO and a higher total iron in bulk water. The number of microorganisms is not a decisive factor of corrosion, even though the counts of bacteria had a close relationship with DO. On the basis of the detection of the 10 kinds of nitrate-reducing bacteria by Miseq sequencing, NRB of the biofilm biomass accounts for 18.3% on the 30th day and 20.5% on the 55th day. Even though aerobic NRBs go into the biofilm later than the facultative anaerobic NRBs, the growth of the anaerobic NRBs is not affected.
Domaine de référence : Biocorrosion
Auteur Qiu Wei, Li Weiyu, He Junguo, Zhao Hongyu, Liu Xiuming, Yuan Yixing
Année de parution : 2018.
Mots-clés : Ductile cast iron pipe, Miseq sequencing, Water distribution system.
Type de document : Article de revue.
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Corrosion behavior of X65 steel in seawater containing sulfate reducing bacteria under aerobic conditions

Résumé : The corrosion behavior of X65 steel was investigated in the seawater inoculated with sulfate reducing bacteria (SRB) under the aerobic environment by electrochemical impedance techniques and immersion tests. The corroded morphologies and the composition of the corrosion products were investigated. The variation of the solution parameters including the bacterium number, the pH value and the soluble iron concentration were also investigated. The results indicated that in the SRB-containing system, the impedance responses presented a depressed semi-circle in the initial period, which then turned into the blocked electrode characteristic during the later immersion. The biofilm, mainly composed of extracellular polymeric substances, Fe(OH)3, γ-FeOOH and α-Fe2O3, formed and degraded with the SRB growth. The soluble iron concentration initially increased, then rapidly decreased and later slowly increased. In the SRB-containing seawater under the aerobic environment, the X65 steel was corroded in the initial immersion. The corrosion became inhibited with the forming of the biofilm during the subsequent immersion. The inhibition efficiency rapidly increased in the logarithmic phase, remained stable in the stationary phase and then decreased in the declination phase. In the corrosion process, the biofilm metabolized by SRB played a key role in the corrosion inhibition of X65 steel.
Domaine de référence : Biocorrosion
Auteur Li Qiushi, Wang Jihui, Xing Xuteng, Hu Wenbin
Année de parution : 2018.
Mots-clés : Aerobic environment, Microbiologically influenced corrosion, Sulfate reducing bacteria, X65 steel.
Type de document : Article de revue.
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Methods to assess monitor and control bacterial biofilms

Résumé : The present disclosure describes methods for detecting, monitoring, and modulating (e.g., promoting, enhancing, sustaining, maintaining, reducing, mitigating or eliminating of) biofilm formation, as well as mitigating or eliminating Microbial Influenced Corrosion (MIC) of a metal surface. The method of monitoring includes: providing a test sample; detecting at least one of a prophage gene, a prophage gene expression, a prophage gene transcript, a prophage protein, a prophage metabolite, a prophage intermediate, or a combination thereof, wherein the existence, amount or level of prophage gene expression, a prophage gene transcript, a prophage protein, a prophage metabolite, a prophage intermediate, or a combination thereof relative to a control is indicative of biofilm presence, formation or the state of the biofilm in a sample. The present disclosure also describes a composition for modulating biofilm formation, maintenance, mitigation, reduction, and elimination.
Domaine de référence : Biocorrosion
Auteur Pilloni Giovanni, CHATTERJEE Mohor, He Kuang
Année de parution : 2018.
Mots-clés : bacteria, biofilm, gene, prophage, repressor.
Type de document : Brevet.
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Microbiologically influenced corrosion of 316L stainless steel in the presence of Chlorella vulgaris

Résumé : Chlorella vulgaris is a commonly found alga in the marine environment and has been widely associated with steel corrosion and biofouling. In this study, the corrosion of 316L stainless steel (SS) in the presence of C. vulgaris was monitored using electrochemical measurements like open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves. Surface and corrosion product analysis was conducted using scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and X-ray photoelectron spectroscopy (XPS). SEM images showed the tendency of C. vulgaris cells to cluster together by their exuded extracellular polymeric substances (EPS) and easily adhere to the SS surface, subsequently causing microbiologically influenced corrosion (MIC). The pitting corrosion was observed in the presence of C. vulgaris cells with pit depth of 20 μm formed on the SS surface after 21 days of incubation, indicating that C. vulgaris accelerated the localized corrosion of 316L SS. XPS and EDS analysis indicated that there were more organic C, O and P in the biofilm in the presence of C. vulgaris, suggesting the better growth of C. vulgaris on the 316L SS surface. In the daytime, C. vulgaris was more active and corrosive as it could produce oxygen through photosynthesis, resulting in increase of the dissolved oxygen (DO) concentration in the bulk solution and biofilm. These results indicated that the change of DO was closely related to the corrosion process.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Sharma Mohita, Wang Junlei, Cheng Y. Frank, Liu Hongfang
Année de parution : 2018.
Mots-clés : 316L stainless steel, Biofilm, Chlorella vulgaris, Microbiologically influenced corrosion, XPS.
Type de document : Article de revue.
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Microbiologically-enhanced galvanic corrosion of the steel beneath a deposit in simulated oilfield-produced water containing Desulfotomaculum nigrificans

Résumé : In this work, microbiologically-enhanced galvanic corrosion between the carbon steel beneath a deposit and bare steel was investigated in simulated oilfield-produced water containing sulfate-reducing bacteria (SRB), in this case Desulfotomaculum nigrificans. The results show that the SRB enhance the generation of a galvanic coupling effect between bare steel and the steel under the deposit, due to their different electrochemical potentials, resulting in accelerated corrosion of the steel under the deposit. In this galvanic couple the bare steel serves as the cathode and the steel under the deposit as the anode. As time increases, the bare steel also suffers from SRB-induced microbiologically influenced corrosion. The galvanic effect is reduced after a long period of incubation due to decreasing SRB activity. Moreover, in the presence of SRB the localized corrosion initiated on the steel under the deposit is greater than that occurring on bare steel.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Zhong Xiankang, Liu Hongfang, Frank Cheng Y.
Année de parution : 2018.
Mots-clés : Galvanic corrosion, Microbiologically influenced corrosion, Sulfate-reducing bacteria, Under deposit corrosion.
Type de document : Article de revue.
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Study of Corrosion Behavior of Oil Gathering Facilities with Co2 Flooding In Low-Permeability Oilfields | SpringerLink

Domaine de référence : Biocorrosion
Année de parution : 2018.
Type de document : Page Web.
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Effect of strain rate on stress corrosion cracking of X100 pipeline steel in environments with sulfate-reducing bacteria

Résumé : Pipelines installed in the seabed for long periods suffer from high stress levels, and the sea mud environment is complex because it contains various microorganisms that make pipelines prone to stress corrosion cracking (SCC). In this study, a self-designed stress electrochemical corrosion test device was adopted to ensure the normal growth and metabolism of sulfate-reducing bacteria (SRB). The effects of strain rate on the SCC behavior of X100 pipeline steel with SRB in a simulation solution of sea mud from the South China Sea were studied using the slow strain rate test, electrochemical impedance spectroscopy, and scanning electron microscopy fractography. Results show that SRB can promote the stress corrosion susceptibility of X100 pipeline steel. As strain rate increases, the stress corrosion susceptibility decreases in general. When the strain rate is 5 × 10−7 × s−1, the stress corrosion susceptibility is largest and SCC occurs. Under the impact of SRB and strain rate, the stress corrosion fracture mechanism is hydrogen embrittlement mechanism. With the increase in strain rate, the effect of SRB becomes weak and the stress corrosion susceptibility shows a decreasing trend in general. Consequently, SCC does not occur in the specimen and the fracture is dominated by mechanical factors.
Domaine de référence : Biocorrosion
Auteur Wu Ming, Gong Ke, Xie Fei, Wang Dan, Liu Guangxin
Année de parution : 2018.
Type de document : Article de revue.
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Corrosion of X80 pipeline steel under sulfate-reducing bacterium biofilms in simulated CO2-saturated oilfield produced water with carbon source starvation

Résumé : Corrosion of X80 pipeline steel under sulfate-reducing bacterium (SRB) biofilms, which formed in a culture medium at different times, in a simulated CO2-saturated oilfield produced water was investigated. Both planktonic and sessile SRB cells survived after 21 days of immersion in the water under carbon source starvation. The biofilms pre-cultured with a longer time increased the corrosion rate of the steel. At 37 °C, it took about 4 days for SRB to grow and then participate in the steel corrosion. The SRB also facilitated localized corrosion. The SRB biofilm, once deactivated, would no longer affect the steel corrosion.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Gu Tingyue, Zhang Guoan, Liu Hongfang, Cheng Y. Frank
Année de parution : 2018.
Mots-clés : A. Carbon steel, B. SEM, B. XPS, C. Microbiological corrosion.
Type de document : Article de revue.
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Steel resistant to SRB (sulfate-reducing bacteria) corrosion as well as application and preparation method of steel

Résumé : The invention discloses steel resistant to SRB (sulfate-reducing bacteria) corrosion as well as an application and a preparation method of the steel. The steel is prepared from main chemical components in percentage by weight as follows: smaller than or equal to 0.04% of C, 0.1%-0.5% of Si, smaller than or equal to 0.5% of Mn, 16%-24% of Cr, 0.15%-1.5% of Cu, 1.5%-3.5% of Al, 0.01%-0.1% of Ce and the balance of Fe and inevitable impurities. The preparation method of the steel resistant to SRB corrosion comprises steps as follows: the raw materials are mixed and subjected to smelting and casting, and a final product component is formed; the final product component is subjected to high-temperature annealing heat treatment, the heating temperature is 1150-1250 DEG C, and the heat preservation time is 60-120 min. The prepared steel can effectively resist corrosion of SRB from the external environment, the yield strength is higher than 380 MPa, requirements of J55 steel grade are met, and the problem of premature failure of pipes for oil recovery in a water injection well due to SRB corrosion can be solved very well.
Domaine de référence : Biocorrosion
Auteur 田青超, 任忠鸣
Année de parution : 2017.
Type de document : Brevet.
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Polymers for Combating Biocorrosion

Résumé : Biocorrosion has been considered as big trouble in many industries and marine environments due to causing great economic loss. The main disadvantages of present approaches to prevent corrosion include being limited by environmental factors, being expensive, inapplicable to field, and sometimes inefficient. Studies show that polymer coatings with anti-corrosion and anti-microbial properties have been widely accepted as a novel and effective approach to preventbiocorrosion. The main purpose of this review is to summarize up the progressive status of polymer coatings used for combating microbially-induced corrosion. Polymers used to synthesize protective coatings are generally divided into three categories: i) traditional polymers incorporated with biocides, ii) antibacterial polymers containing quaternary ammonium compounds, and iii) conductive polymers. The strategies to synthesize polymer coatings resort mainly to grafting anti-bacterial polymers from the metal substrate surface using novel surface-functionalization approaches, such as free radical polymerization, chemically oxidative polymerization and surface-initiated atom transfer radical polymerization, as opposed to the traditional approaches of dip coating or spin coating.
Domaine de référence : Biocorrosion
Auteur Guo Jing, Yuan Shaojun, Jiang Wei, Lv Li, Liang Bin, Pehkonen Simo O.
Année de parution : 2018.
Mots-clés : Antibacterial, biocides, biocorrosion, Conductive polymers, Polymeric coatings, Quaternary Ammonium Compounds.
Type de document : Article de revue.
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Metal Biocorrosion of a Water Well : A Case Study

Domaine de référence : Biocorrosion
Auteur Calbo Vicente, Furlong Octavio Javier, Julián Silvia Viviana
Année de parution : 2018.
Type de document : Article de revue.
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Bio-Reduction of Graphene Oxide Using Sulfate-Reducing Bacteria and Its Implication on Anti-Biocorrosion

Résumé : In this paper, we developed an environmental friendly, cost effective, simple and green approach to reduce graphene oxide (GO) by a sulfate-reducing bacterium Desulfovibrio desulfuricans. The D. desulfuricans reduces exfoliated GO to reduced graphene oxide (rGO) at 25 °C in an aqueous solution without any toxic and environmentally harmful reducing agents. The rGO was characterized with X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscope, X-ray Photoelectron Spectroscopy and Raman Spectroscopy. The analysis results showed that rGO had excellent properties and multi-layer graphene sheets structure. Furthermore, we demonstrated that D. desulfuricans, one of the primary bacteria responsible for the biocorrosion of various metals, might reduce GO to rGO on the surface of copper and prevented the corrosion of copper, which confirmed that electrophoretic deposition of GO on the surface of metals had great potential on the anti-biocorrosion applications.
Domaine de référence : Biocorrosion
Auteur Song Tian-Shun, Tan Wei-Min, Xie Jingjing
Année de parution : 2018.
Mots-clés : Anti-Biocorrosion, Desulfovibrio desulfuricans, Graphene Oxide, Green Synthesis, Reduced Graphene Oxide.
Type de document : Article de revue.
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Interactions of Desulfovibrio desulfuricans biofilm with 2205 duplex stainless steel – the role of microstructure

Résumé : The paper presents the results on sulfate‐reducing bacteria (SRB) induced corrosion of 2205 duplex stainless steel (DSS) in as‐received and thermally aged conditions. Biofilm formation and damage process...
Domaine de référence : Biocorrosion
Auteur Michalska Joanna, Chmiela Bartosz, Simka Wojciech
Année de parution : 2018.
Type de document : Article de revue.
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Damage to offshore production facilities by corrosive microbial biofilms

Résumé : In offshore production facilities, large amounts of deaerated seawater are continuously injected to maintain pressure in oil reservoirs and equivalent volumes of fluids, composed of an oil/gas, and water mixture are produced. This process, brewing billions of liters of biphasic fluids particularly rich in microorganisms, goes through complex steel pipeline networks that are particularly prone to biofilm formation. Consequently, offshore facilities are frequently victims of severe microbiologically influenced corrosion. Understanding of microbiologically influenced corrosion is constantly growing. In the laboratory, the inventory of potentially corrosive microorganisms is increasing and microbial biochemical and bioelectrical processes are now recognized to be involved in corrosion. However, understanding of corrosive multispecies biofilms and the complex metabolic processes associated with corrosion remains a considerable challenge as simple laboratory biofilms comprising pure or defined mixed cultures poorly represent the complexity of in situ biofilms. Complementary, antagonistic, and parallel microbial pathways occur within the complex microbial and inorganic matrix of the biofilms which can lead to high corrosion rates. This mini-review explores models of microbiologically influenced corrosion and places them in the context of the multispecies biofilms observed in situ. Consequences of mitigation strategies on biofilm corrosiveness and dispersal are also discussed.
Domaine de référence : Biocorrosion
Auteur Vigneron Adrien, Head Ian M., Tsesmetzis Nicolas
Année de parution : 2018.
Type de document : Article de revue.
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Method for monitoring microbiologically induced corrosion on metal surfaces

Résumé : A method for monitoring microbiologically induced corrosion on metal surfaces in contact with a fluid. The method comprises adding to the fluid a silanol compound or silanol compound precursor having a group detectible by ultraviolet spectrophotometry or fluorescence spectroscopy, or which is isotopically enriched.
Domaine de référence : Biocorrosion
Année de parution : 2016.
Type de document : Brevet.
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Advances in concrete materials for sewer systems affected by microbial induced concrete corrosion : A review

Résumé : Microbial induced concrete corrosion (MICC) is recognized as one of the main degradation mechanisms of subsurface infrastructure worldwide, raising the demand for sustainable construction materials in corrosive environments. This review aims to summarize the key research progress acquired during the last decade regarding the understanding of MICC reaction mechanisms and the development of durable materials from an interdisciplinary perspective. Special focus was laid on aspects governing concrete - micoorganisms interaction since being the central process steering biogenic acid corrosion. The insufficient knowledge regarding the latter is proposed as a central reason for insufficient progress in tailored material development for aggressive wastewater systems. To date no cement-based material exists, suitable to withstand the aggressive conditions related to MICC over its entire service life. Research is in particular needed on the impact of physiochemical material parameters on microbial community structure, growth characteristics and limitations within individual concrete speciation. Herein an interdisciplinary approach is presented by combining results from material sciences, microbiology, mineralogy and hydrochemistry to stimulate the development of novel and sustainable materials and mitigation strategies for MICC. For instance, the application of antibacteriostatic agents is introduced as an effective instrument to limit microbial growth on concrete surfaces in aggressive sewer environments. Additionally, geopolymer concretes are introduced as highly resistent in acid environments, thus representing a possible green alternative to conventional cement-based construction materials.
Domaine de référence : Biocorrosion
Auteur Grengg Cyrill, Mittermayr Florian, Ukrainczyk Neven, Koraimann Günther, Kienesberger Sabine, Dietzel Martin
Année de parution : 2018.
Mots-clés : Acid corrosion, Antimicrobial agents, Concrete, Geopolymers, Microbiological corrosion, Microorganism interactions, Sustainable construction.
Type de document : Article de revue.
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Simulation of the marine environment using bioreactor for investigation of 2507 duplex stainless steel corrosion in the presence of marine isolated Bacillus Vietnamensis bacterium

Résumé : The effect of marine B. vietnamensis, isolated from East Sea, China, on the corrosion behavior of SAF 2507 duplex stainless steel (DSS) was studied. A flat plate bioreactor was used to simulate the marine environment. And the environmental parameters such as temperature, pH, flow rate and oxygen content were controlled in bioreactor which operated aerobically for 30 days with either inoculated or sterile artificial seawater. Electrochemical studies demonstrated a noticeable decrease in open circuit potential and an increase in current density in solutions containing B. vietnamensis compared to the sterile artificial seawater which confirmed the enhancement of corrosion rate of 2507 DSS in the presence of bacterium. FESEM images showed the presence of porous and heterogeneous biofilm and oxide layer on the 2507 DSS surface in the presence of bacterium. The heterogeneity of biofilm and different thicknesses of biofilm made the oxygen concentration cells on the 2507 DSS surface and induced localized corrosion at longer exposure times. The biofilm composition also identified by FTIR.
Domaine de référence : Biocorrosion
Auteur Sun Zhaohui, Moradi Masoumeh, Chen Yanxia, Bagheri Robabeh, Guo Pushan, Yang Lijing, Song Zhenlun, Xu Cheng
Année de parution : 2018.
Mots-clés : Bioreactor, EIS, FESEM, FTIR, Microbiologically influenced corrosion.
Type de document : Article de revue.
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Effect of sulfate-reducing bacteria and cathodic potential on stress corrosion cracking of X70 steel in sea-mud simulated solution

Résumé : The submarine oil and gas pipelines steel buried in sea mud are always influenced by microorganisms and cathodic protection potential. In this paper, the single and combined effect of sulfate-reducing bacteria (SRB) and cathodic potential on stress corrosion cracking (SCC) behavior of X70 pipeline steel in sea-mud simulated solution was investigated by slow strain rate tests and fractographic observation. Whether in sterile or SRB-inoculated solution, the SCC susceptibility at −850 mVSCE showed a decline compared with that at open circuit potential. The reason is that the lower number of corrosion pits and the slighter hydrogen evolution at −850 mVSCE inhibited both of the cracks nucleation and propagation. The SCC susceptibility of X70 steel increased drastically as the cathodic potential shifted from −850 mVSCE to −1200 mVSCE in sterile or SRB-inoculated solution. SRB assisted pitting corrosion and the promotion effect on hydrogen permeation make SRB plays a positive role in promoting SCC susceptibility. The SCC susceptibility can be elevated in the co-existence of SRB and cathodic potential but the combined action between them became limited as the potential shifted negatively, which was attributed to the fact that alkalization of solution caused by cathodic potential restricts the growth of SRB.
Domaine de référence : Biocorrosion
Auteur Sun Dongxu, Wu Ming, Xie Fei
Année de parution : 2018.
Mots-clés : Cathodic potential, Pipeline steel, Sea-mud simulated solution, Stress corrosion cracking, Sulfate-reducing bacteria.
Type de document : Article de revue.
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The presence of nitrate- and sulfate-reducing bacteria contributes to ineffectiveness souring control by nitrate injection

Résumé : Nitrate injection has been widely used to minimize the production of biological hydrogen sulfide in oil and gas field industry, by controlling the growth of sulfate-reducing bacteria (SRB) chemically and biologically. This study aimed to investigate the changes in the bacterial community in response to nitrate addition used to control biological souring. Specifically, we examined the effect of nitrate addition in an artificial souring experiment, using diluted crude oil as substrate and electron donor. Desulfotignum sp. was the predominant SRB under all conditions tested. Addition of nitrate at the beginning (N0) repressed the growth of SRB, as revealed by chemical and bacterial community analysis, concomitant with significant growth of the nitrate-reducing bacteria (NRB) Thalassospira sp. Nitrate addition after SRB growth (at day 28, N28) successfully remediated the sulfide produced by SRB, but no significant reduction in sulfate was observed subsequently; moreover, the bacterial communities before and after nitrate addition remained identical. Isolation of Desulfotignum YB01 (D. YB01) proved the resistance of this predominant SRB in high nitrate environment. Simultaneous reduction of sulfate and nitrate by D. YB01 was also observed in this study. Therefore, the phenomenon in the N28 experiment might be the result of the role of Arcobacter sp. which are nitrate-reducing sulfide-oxidizing bacteria, and/or the ability of Desulfotignum sp. to reduce nitrate and/or nitrite as a stress response. Thus, SRB might persist after nitrate addition, potentially causing subsequent SRB outbreaks.
Domaine de référence : Biocorrosion
Auteur Kamarisima, Hidaka Kohei, Miyanaga Kazuhiko, Tanji Yasunori
Année de parution : 2018.
Mots-clés : Nitrate injection, Nitrate-reducing bacteria, Secondary recovery, Souring, Sulfate-reducing bacteria.
Type de document : Article de revue.
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Plus de références Biocorrosion


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Experimental study of fouling process and antifouling effect in convective heat transfer under ultrasonic treatment

Résumé : An experimental study was carried out by a dynamic fouling monitor system to investigate the fouling process in convective heat transfer by ultrasonic treatment. During the experiment, the cooling water in heat exchanger was used as working fluid with the inlet temperature of 22.5 °C and 44 °C and the initial hardness of 300 mg/L and 500 mg/L, respectively. For all cases the inlet temperature of hot water was kept at 70°C, and the flowrates of cooling water and hot water were set at 0.77 m3/h and 0.81 m3/h, respectively. In this experimental setup, a double-tube heat exchanger was served as a test section of heat transfer, in which hot water flows inside the inner copper tube and cooling water flows in the annular gap between the two tubes, thus forming a counter-flow situation. Further, an ultrasonic device was installed for water treatment with a frequency of 20.7 kHz and power ranging from 0 to 75 W. The results showed that the fouling resistance for hard water increased evidently with increasing of water temperature and hardness. With the ultrasonic treatment, the fouling resistance decreased remarkably compared with the untreated case, and the asymptotic fouling resistance decreased monotonously with increasing of the ultrasonic power. Subsequently, the crystal morphology of calcium carbonate was observed in microscopic view and the transform of crystal from the vaterite to aragonite and calcite was analyzed based on the theory of the formation energy. It was confirmed that the ultrasonic treatment may have significant effect on the crystal shape, and more aragonites appeared with increasing powers of ultrasound.
Domaine de référence : Antifouling
Auteur Hou Tengfei, Chen Yongchang, Wang Zepeng, Ma Chongfang
Année de parution : 2018.
Mots-clés : convective heat transfer, crystal morphology, fouling resistance, ultrasonic treatment.
Type de document : Article de revue.
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Antifouling materials

Résumé : The invention provided herein presents a novel family of antifouling agents based on hydroxylated and fluorinated compounds.
Domaine de référence : Antifouling
Année de parution : 2017.
Type de document : Brevet.
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Antifouling, fouling release and antimicrobial materials for surface modification of reverse osmosis and nanofiltration membranes

Résumé : Membrane fouling, which arises from the nonspecific interaction between the membrane surface and foulants, significantly impedes the efficient application of membrane technology. Antifouling and antimicrobial materials are important classes of functional materials for the surface modification of reverse osmosis and nanofiltration membranes. Applications of various organic and inorganic materials having different characteristics such as size, surface charge, hydrophilicity, functionality and biocidal activity, provide protective/sacrificial layers to the membrane surface against different foulants and microorganisms. This review summarizes the properties and applications of organic and inorganic materials, antifouling mechanisms, and surface modification of pre-formed membranes. Materials such as zwitterionic polymers, neutral polymers, polyelectrolytes, amphiphilic polymers, quaternary ammonium polymers, biopolymers, hydrophilic polymers, polydopamine, inorganic salts, and nanomaterials have shown great potential in reducing foulant adhesion and/or proliferative microbial growth on membrane surfaces.
Domaine de référence : Antifouling
Auteur Choudhury Rikarani R., Gohil Jaydevsinh M., Mohanty Smita, Nayak Sanjay K.
Année de parution : 2018.
Type de document : Article de revue.
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Anti-biofouling superhydrophobic surface fabricated by picosecond laser texturing of stainless steel

Résumé : Anti-biofouling technology is based on specifically designed materials and coatings. This is an enduring goal in the maritime industries, such as shipping, offshore oil exploration, and aquaculture. Recently, research of the relationship between wettability and antifouling effectiveness has attracted considerable attention, due to the anti-biofouling properties of the lotus leaf and shark skin. In this study, super-hydrophobic surfaces (SHSs) with controllable periodic structures were fabricated on AISI304 stainless steel by a picosecond laser, and their anti-biofouling performance were investigated by seawater immersion for five weeks in summertime. The results showed that the specimens with SHS demonstrate significant anti-biofouling effect as compared with the bare stainless steel plate. We observed that nearly 50% decrease of the average microbe attachment area ratio (Avg. MAAR) could be obtained. The micro-groove SHS with more abundant hierarchical micro-nano structures showed better anti-biofouling performance than the micro-pit SHS.
Domaine de référence : Antifouling
Auteur Sun Ke, Yang Huan, Xue Wei, He An, Zhu Dehua, Liu Wenwen, Adeyemi Kenneth, Cao Yu
Année de parution : 2018.
Mots-clés : Anti-biofouling, Laser ablation, Laser induced surface hierarchical micro-nano structures, Stainless steel, Superhydrophobic surface.
Type de document : Article de revue.
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Biocidal Microcapsules for Biofouling Control

Résumé : The present invention is directed to bioactive microcapsules and to the process for their production. More in particular, the present invention relates to the production of bioactive microcapsules, or porous microspheres by a water-in-oil (W/O) microemulsion method combined with interfacial polymerization, involving the full or partial covalent immobilization of biocides and/or modified biocides within the microcapsules shell, or porous microspheres. In addition, the present invention further relates to the use of said bioactive microcapsules/microspheres for controlled release of biocides in antifouling application and their incorporation in matrices such as marine coatings.
Domaine de référence : Antifouling
Auteur MARQUES Ana Clara Lopes, GERALDES Elisabete Ribeiro Silva, BORDADO Joao Carlos Moura
Année de parution : 2018.
Type de document : Brevet.
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Hydrophobicity and Superhydrophobicity in Fouling Prevention in Sea Environment

Résumé : Abstract This chapter contains sections titled: Introduction Antifouling Options Problem Statement Coatings with Special Wettability and Performance Against Biofouling General Discussion Summary
Domaine de référence : Antifouling
Auteur Ferrari Michele, Cirisano Francesca
Année de parution : 2018.
Mots-clés : coatings, fouling control, marine environment, seawater, Superhydrophobic surface, wetting.
Type de document : Article de revue.
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Biodegradable Polymer with Hydrolysis-Induced Zwitterions for Antibiofouling

Résumé : Persistent protein resistance is critical for marine antibiofouling. We have prepared copolymer of 2-methylene-1,3-dioxepane (MDO), tertiary carboxybetaine ester (TCB), and 7-methacryloyloxy-4-methylcoumarin (MAMC) via radical ring-opening polymerization, where MDO, TCB, and MAMC make the polymer degradable, protein resistible, and photo-cross-linkable, respectively. Our study shows that the polymer can well adhere to the substrate with controlled degradation and water adsorption rate in artificial seawater (ASW). Particularly, the polymer film can generate zwitterions via surface hydrolysis in ASW. Quartz crystal microbalance with dissipation measurements reveal that such hydrolysis-induced zwitterionic surface can effectively resist nonspecific protein adsorption. Moreover, the surface can inhibit the adhesion of marine bacteria Pseudomonas sp. and Vibrio alginolyticus as well as clinical bacterium Escherichia coli.
Domaine de référence : Antifouling
Auteur Xie Qingyi, Xie Qianni, Pan Jiansen, Ma Chunfeng, Zhang Guangzhao
Année de parution : 2018.
Type de document : Article de revue.
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Hydrophilic Self-Replenishing Coatings with Long-Term Water Stability for Anti-Fouling Applications

Résumé : Hydrophilic coatings have recently emerged as a new approach to avoid the adhesion of (bio)organisms on surfaces immersed in water. In these coatings the hydrophilic character is crucial for the anti-fouling (AF) performance. However, this property can be rapidly lost due to the inevitable damages which occur at the surface, reducing the long-term effectiveness of the AF functionality. We report hydrophilic polycarbonate-mPEG polyurethane coatings with tunable hydrophilic properties as well as an excellent and long-term stability in water. The coatings exhibit low protein adhesion values and are able to self-replenish their hydrophilicity after damage, due to the existence of a reservoir of hydrophilic dangling chains incorporated in the bulk. The combination of low Tg and sufficient mobility of the mPEG dangling chains (enabled by chains with higher molecular weight) proved to be crucial to ensure autonomous surface hydrophilicity recovery when the coatings were immersed in water. This coatings and design approach offer new possibilities towards high performance AF coatings with an extended service life-time which can be used in several major applications areas, such as marine and biomedical coatings, with major economic and environmental benefits.
Domaine de référence : Antifouling
Auteur Jiménez-Pardo Isabel, Ven Leendert G. J. van der, Benthem Rolf A. T. M. van, With Gijsbertus de, Esteves A. Catarina C.
Année de parution : 2018.
Type de document : Article de revue.
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Bioinspired fish-scale-like stainless steel surfaces with robust underwater anti-crude-oil-fouling and self-cleaning properties

Résumé : Stainless steel (SS) have been widely used in marine structures and food industry due to its high corrosion resistance and excellent mechanical strength. Marine structures such as ships, ocean engineering and offshore rigs, are easily attacked by crude oil generated by oil spills and SS vessels applied in food industry are fouled by the organic matters in the fluid. Here, fish-scale-like SS surfaces with superhydrophilic and underwater superoleophobic property, including 316 L SS mesh and 304 SS plate, are designed by a facile chemical-based oxidation method. The obtained SS surfaces show excellent underwater anti-crude-oil-fouling property and thermal stability. Furthermore, the obtained 316 L SS mesh can effectively separate crude oil/water mixture solely driven by gravity. Significantly, the as-prepared SS surfaces possess robust antifouling and self-cleaning property during multiple cycles with the aid of Fenton-like catalytic reaction between Fe (III) and H2O2 or calcination at high temperature. Therefore, the fish-scale-like SS surfaces show great potential in a wide range of fields, such as marine antifouling, oil-water separation and food industry.
Domaine de référence : Antifouling
Auteur Peng Yubing, Wen Gang, Gou Xuelian, Guo Zhiguang
Année de parution : 2018.
Mots-clés : crude oil-water separation, marine anti-fouling, self-cleaning, stainless steel, superhydrophilic/underwater superoleophobic.
Type de document : Article de revue.
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A combined criterion of surface free energy and roughness to predict the wettability of non-ideal low-energy surfaces

Résumé : The significance of wettability between solid and liquid substances in different fields encourages scientists to develop accurate models to estimate the resultant apparent contact angles. Surface free energy (SFE), which is principally defined for ideal (flat) surfaces, is not applicable to predict the wettability of real (rough) surfaces. This paper introduces a new parameter, namely normalized surface free energy (NSFE) as a combination of SFE and roughness, to predict the contact angle of liquids on non-ideal low-energy surfaces. The remarkable consistency of the predicted and measured contact angles of liquids on some rough surfaces also confirm the validity of the approach.
Domaine de référence : Antifouling
Auteur Shaker Majid, Salahinejad Erfan
Année de parution : 2018.
Mots-clés : Roughness, Surface free energy, Wettability.
Type de document : Article de revue.
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Bacterial attachment and biofilm formation on stainless steel surface and their in vitro inhibition by marine fungal extracts

Résumé : This study evaluates anti-biofilm activity of four extracts from marine fungi; Penicillium citrinum PR1T4, Sarocladium strictum PP2L4, Aspergillus sydowii PR3T13, and Aspergillus spp. PR5T4 against Staphylococcus aureus, Listeria monocytogenes (ATCC 19115), Escherichia coli, and Salmonella typhi (ATCC 14028). The ability of bacterial cells to adhere, detach, and form biofilm on stainless steel surface were examined and ethyl acetate extract of the fungal culture (15 mg/ml) were tested for anti-biofilm activity for 3, 6, 9, 12, and 15 days. E. coli showed the highest ability to adhere (>8 log CFU/cm2) and lowest detachment (<4 log CFU/cm2) after 24, 48, and 72 hr. Extract PP2L4 had the highest anti-biofilm activity against S. typhi (1.70 ± 0.04 log CFU/cm2). Fungal extracts, bacteria, and incubation period were significant factors and their interactions were significant. The results showed that marine fungal extracts are important natural sources for anti-biofilm agents that have high potential as food-contact surface sanitizers. Practical applications Biofilm removal from food contact surfaces has been one of the greatest challenges for food industry. There have been efforts to explore natural agents with anti-biofilm properties. This study showed that marine-derived fungal extracts significantly reduced the number of attached cell on stainless steel discs and, therefore, is potential candidates for anti-biofilm agents. Special attention would be given to the fungal isolate (S. strictum PP2L4) that presented a promising activity against the gram-negative S. typhi. As the active fungal extracts were unable to completely remove the adhered bacterial cells, optimization is recommended to increase probability of isolating active compounds capable for complete biofilm removal. The active compounds could be used in sanitizer formulation and applied on various food-contact surfaces (e.g., stainless steel and plastic) at food related industries such as in institutional food service kitchens as well as home kitchens.
Domaine de référence : Antifouling
Auteur Mahyudin Nor Ainy, Mat Daud Noor Ifatul Hanim, Ab Rashid Nor-Khaizura Mahmud, Muhialdin Belal J., Saari Nazamid, Noordin Wan Norhana
Année de parution : 2018.
Type de document : Article de revue.
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Synthesis, antibacterial activity, and application in the antifouling marine coatings of novel acylamino compounds containing gramine groups

Résumé : Basing on the previous syntheses of ester compounds containing gramine functional groups, the researchers synthesized two novel acylamino compounds containing gramine groups and the structures of target compound were established using 1HNMR, 13CNMR, IR spectra, and elemental analysis. The antibacterial activity of the synthesized compounds against Escherichia coli and Staphylococcus aureus, as well as their antifouling activity were studied. The results showed that these compounds possessed high antibacterial activity and a minimal inhibitory concentration value of 0.03 mg/mL against bacteria. Moreover, their antifouling properties are superior to cuprous oxide and chlorothalonil, which are widely used as antifoulants. Furthermore, quantitative structure activity relationship studies with antibacterial activity of the nine gramine compounds were established. These provide theoretical and technical bases for preparing environment-friendly antifouling coatings with the compounds as antifouling agents.
Domaine de référence : Antifouling
Auteur Feng Kang, Li Xia, Yu Liangmin
Année de parution : 2018.
Mots-clés : Acylamino compounds, Antibacterial activity, Antifouling property, Gramine, Quantitative structure activity relationship.
Type de document : Article de revue.
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Anti-biofouling superhydrophobic surface fabricated by picosecond laser texturing of stainless steel

Résumé : Anti-biofouling technology is based on specifically designed materials and coatings. This is an enduring goal in the maritime industries, such as shipping, offshore oil exploration, and aquaculture. Recently, research of the relationship between wettability and antifouling effectiveness has attracted considerable attention, due to the anti-biofouling properties of the lotus leaf and shark skin. In this study, super-hydrophobic surfaces (SHSs) with controllable periodic structures were fabricated on AISI304 stainless steel by a picosecond laser, and their anti-biofouling performance were investigated by seawater immersion for five weeks in summertime. The results showed that the specimens with SHS demonstrate significant anti-biofouling effect as compared with the bare stainless steel plate. We observed that nearly 50% decrease of the average microbe attachment area ratio (Avg. MAAR) could be obtained. The micro-groove SHS with more abundant hierarchical micro-nano structures showed better anti-biofouling performance than the micro-pit SHS.
Domaine de référence : Antifouling
Auteur Sun Ke, Yang Huan, Xue Wei, He An, Zhu Dehua, Liu Wenwen, Adeyemi Kenneth, Cao Yu
Année de parution : 2018.
Mots-clés : Anti-biofouling, Laser ablation, Laser induced surface hierarchical micro-nano structures, Stainless steel, Superhydrophobic surface.
Type de document : Article de revue.
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Research progress of nano self - cleaning anti-fouling coatings

Résumé : There are many methods of evaluating the performance of nano self-cleaning anti-fouling coatings, such as carbon blacking method, coating reflection coefficient method, glass microbead method, film method, contact angle and rolling angle method, organic degradation method, and the application of performance evaluation method in self-cleaning antifouling coating. For the more, the types of nano self-cleaning anti-fouling coatings based on aqueous media was described, such as photocatalytic self-cleaning coatings, silicone coatings, organic fluorine coatings, fluorosilicone coatings, fluorocarbon coatings, polysilazane self-cleaning coatings. The research and application of different kinds of nano self-cleaning antifouling coatings are anlysised, and the latest research results are summed.
Domaine de référence : Antifouling
Auteur Liu Y., Zhao Y. J., Teng J. L., Wang J. H., Wu L. S., Zheng Y. L.
Année de parution : 2017.
Type de document : Article de revue.
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Novel composite graphene oxide/chitosan nanoplates incorporated into PES based nanofiltration membrane : Chromium removal and antifouling enhancement

Résumé : In this work, novel nanofiltration membranes with outstanding performance and antifouling properties were fabricated by incorporating composite graphene oxide/chitosan (GOC) nanoplates into the membrane structure. GOC composite nanoplates were prepared by surface modification of GO with chitosan. The GOC nanoplates were then introduced as additives in a polymeric phase in different concentrations (up to 1%) in view of membrane synthesis. these membranes were thoroughly characterized and assessed for their Na2SO4 and CrSO4 rejection and water flux. Furthermore, the antifouling performance of GO and GOC filled membranes in high concentration (1wt%) was investigated. Modified membranes with addition of GOCs showed a higher hydrophilicity, pure water flux and rejection, and a smoother surface compared to a bare PES and a GO incorporated membrane. SEM surface images indicated a more uniformed distribution of GOCs at a high loading rate (1wt%) compared to GO. Due to the uniform dispersion of GOCs, a better antifouling performance was observed than for GO filled membranes. The results indicate that surface modification of GO with chitosan can enhance the membrane performance and properties, due to availability of sites with higher activity.
Domaine de référence : Antifouling
Auteur Bagheripour E., Moghadassi A. R., Hosseini S. M., Van der Bruggen B., Parvizian F.
Année de parution : 2018.
Mots-clés : Composite graphene oxide/chitosan nanoplates, Nanofiltration, Rejection/antifouling characteristic, Surface property.
Type de document : Article de revue.
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A multi-step approach for testing non-toxic amphiphilic antifouling coatings against marine microfouling at different levels of biological complexity

Résumé : Marine biofouling on artificial surfaces such as ship hulls or fish farming nets causes enormous economic damage. The time for the developmental process of antifouling coatings can be shortened by reliable laboratory assays. For designing such test systems, it is important that toxic effects can be excluded, that multiple parameters can be addressed simultaneously and that mechanistic aspects can be included. In this study, a multi-step approach for testing antifouling coatings was established employing photoautotrophic biofilm formation of marine microorganisms in micro- and mesoscoms. Degree and pattern of biofilm formation was determined by quantification of chlorophyll fluorescence. For the microcosms, co-cultures of diatoms and a heterotrophic bacterium were exposed to fouling-release coatings. For the mesocosms, a novel device was developed that permits parallel quantification of a multitude of coatings under defined conditions with varying degrees of shear stress. Additionally, the antifouling coatings were tested for leaching of potential compounds and finally tested in sea trials. This multistep-approach revealed that the individual steps led to consistent results regarding antifouling activity of the coatings. Furthermore, the novel mesocosm system can be employed for advanced antifouling analysis including metagenomic approaches for determination of microbial diversity attaching to different coatings under changing shear forces.
Domaine de référence : Antifouling
Auteur Zecher Karsten, Aitha Vishwa Prasad, Heuer Kirsten, Ahlers Herbert, Roland Katrin, Fiedel Michael, Philipp Bodo
Année de parution : 2018.
Mots-clés : Antifouling, Bacteria diatom interaction, Biofilm, Biofouling, Fouling release, Mesocosm, Microfouling, Shear stress.
Type de document : Article de revue.
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Enhancement of graft density and chain length of hydrophilic polymer brush for effective marine antifouling

Résumé : 2-Hydroxyethyl methacrylate polymer brushes with various grafting densities and chain lengths were prepared through surface-initiated atom transfer radical polymerization. X-ray photoelectron spectra, ellipsometry measurement, contact angle measurement, and atom force microscope were used to characterize the prepared polymer brush. The biofouling assays of polymer brush were investigated by adhesion of Dunaliella tertiolecta, Navcular sp., and Bovine Serum Albumin protein and by static marine immersion field test. Besides, hydroxyl and sulfonate-terminated self-assembled monolayers, anionic charged 3-sulfopropyl methacrylate potassium salt polymer brush were prepared for comparison. Results suggest that the settlement of microorganisms can be largely reduced by polymer with enough polymer chain length and grafting density. More importantly, static immersion field tests indicate that hydrophilic polymer film with enough hydration layer thickness is necessary for long-term marine antifouling application. This comprehensive investigation is of great importance to understanding their influence on the adhesion of marine microorganism. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46232.
Domaine de référence : Antifouling
Auteur Yang Wufang, Zhang Ran, Wu Yang, Pei Xiaowei, Liu Yupeng, Zhou Feng
Année de parution : 2018.
Mots-clés : biomaterials, coatings, grafting, proteins, self-assembly.
Type de document : Article de revue.
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The antifouling effects of copper-oxide filler incorporated into paint-based protective films applied to steam surface condenser tubes

Résumé : Paint-based protective films (PPFs) are used to protect condenser tubes from corrosion and erosion but have been shown to be susceptible to biofouling. Here the biocidal properties of copper-oxide fillers incorporated into PPFs are explored in this paper. Specifically two PPFs filled with 20% and 50% filler (by weight) are tested in parallel with a non-biocidal ordinary epoxy PPF, and bare stainless steel tube. Using double-pipe co-current flow heat exchangers installed at a thermal power plant, actual cooling water exiting the condenser is evenly distributed between the test tubes. Heat transfer in the condenser is simulated by heated water flowing through each annulus of the double-pipe heat exchangers, thereby maintaining repeatable outer convection conditions. An exposure test of 125 days shows that the 50% biocide filled PPF has the lowest fouling factor of all the tubes. The non-biocidal epoxy has the highest fouling factor and the 20% filled PPF behaves similarly. Both of these are greater than the bare stainless steel control tube. The 50 % filled PPF is compared to the fouling of an existing admiralty brass tube and the shape of the fouling curves are similar. This evidence suggests that provided the filler concentration is sufficiently high, there is the potential for the copper-oxide filler to reduce the asymptotic composite fouling factor by virtue of its antibacterial properties.
Domaine de référence : Antifouling
Auteur Reuter Hanno C., Owen Michael, Goodenough John
Année de parution : 2018.
Type de document : Article de revue.
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Ecological responses to ocean acidification by developing marine fouling communities

Résumé : Increasing levels of CO₂ in the atmosphere are rapidly affecting ocean chemistry, leading to increased acidification (i.e., decreased pH) and reductions in calcium carbonate saturation state. This phenomenon, known as ocean acidification, poses a serious imminent threat to marine species, especially those that use calcium carbonate. In this dissertation, I use a variety of methods (field-based experiments, surveys, meta-analysis) to understand how marine communities respond to both natural and experimental CO₂ enrichment and how responses could be shaped by species interactions or food availability. I found that ocean acidification influenced community assembly, recruitment, and succession to create homogenized, low diversity communities. I found broadly that soft-bodied, weedy taxa (e.g., algae and ascidians) had an advantage in acidified conditions and outcompeted heavily calcified taxa (e.g., mussels, serpulids) that were more vulnerable to the effects of acidification, although calcified bryozoans and barnacles exhibited mixed responses. Next, I examined an important hypothesis of context dependency in ocean acidification research: that negative responses by calcifiers to high CO₂ could be reduced by higher energy input. I found little support for this hypothesis for species growth and abundance, and in fact found that, for some species, additional food supply exacerbated or brought out the negative effects of CO₂. Further, I found that acidification stress can tip the balance of community composition towards invasion, under resource conditions that enabled the native community to resist invasions. Overall, it is clear that acidification is a strong driving force in marine communities but understanding the underlying energetic and competitive context is essential to predicting climate change responses.
Domaine de référence : Antifouling
Auteur Brown Norah Elizabeth Maclean
Année de parution : 2018.
Type de document : Thèse.
Source : University of British Columbia
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Quantitative analysis of the complete larval settlement process confirms Crisp’s model of surface selectivity by barnacles

Résumé : For barnacle cypris larvae at the point of settlement, selection of an appropriate surface is critical. Since post-settlement relocation is usually impossible, barnacles have evolved finely tuned surface-sensing capabilities to identify suitable substrata, and a temporary adhesion system for extensive surface exploration. The pattern of exploratory behaviour appears complex and may last for several hours, imposing significant barriers to quantitative measurement. Here, we employ a novel tracking system that enables simultaneous analysis of the larval body movement of multiple individuals over their entire planktonic phase. For the first time, to our knowledge, we describe quantitatively the complete settlement process of cyprids as they explore and select surfaces for attachment. We confirm the ‘classic’ behaviours of wide searching, close searching and inspection that comprise a model originally proposed by Prof. Dennis Crisp FRS. Moreover, a short-term assay of cyprid body movement has identified inspection behaviour as the best indicator of propensity to settle, with more inspection-related movements occurring in conditions that also promote higher settlement. More than half a century after the model was first proposed by Crisp, there exists a precise method for quantifying cyprid settlement behaviour in wide-ranging investigations of barnacle ecology and applied studies of fouling management.
Domaine de référence : Antifouling
Auteur Aldred Nick, Alsaab Ahmad, Clare Anthony S.
Année de parution : 2018.
Type de document : Article de revue.
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Investigating the effect of biofouling on propeller characteristics using CFD

Résumé : Increasing pressure is being placed on the marine industry to address ship emissions, regulations to govern the efficient operation of ships in the form of the Energy Efficiency Design Index (EEDI) and Energy Efficiency Operation Index (EEOI) have recently come into force. All aspects of ship design and operation that impact the energy efficiency of ships are subject to revaluation. This paper investigates the detrimental effects of biofouling on the performance of Potsdam Propeller Test Case (PPTC) propeller using Computational Fluid Dynamics (CFD). A previously-developed CFD approach for approximating the surface roughness due to biofouling has been applied in order to predict the effects on propeller characteristics. The roughness effects of a typical coating and different fouling conditions on the propeller performance were predicted for various advance coefficients. The effect proved to be drastic with the most severe fouling condition resulting in a 11.94% efficiency loss at J=0.6 ranging to an alarming 30.33% loss at J=1.2 compared to the smooth condition. The study acts as a proof of concept for the proposed CFD assessment method which can be used as a very practical approach to predicting the impact of realistic fouling conditions on propeller characteristics and energy efficiency.
Domaine de référence : Antifouling
Auteur Owen David, Demirel Yigit Kemal, Oguz Elif, Tezdogan Tahsin, Incecik Atilla
Année de parution : 2018.
Type de document : Article de revue.
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Dextran- and Chitosan-Based Antifouling, Antimicrobial Adhesion, and Self-Polishing Multilayer Coatings from pH-Responsive Linkages-Enabled Layer-by-Layer Assembly

Résumé : To meet the demand for more environmentally friendly antifouling coatings and to improve fouling-resistant coatings with both “offense” and “defense” functionalities, polysaccharides (PSa)-based self-polishing multilayer coatings were developed for combating biofouling. Dextran aldehyde (Dex-CHO) and carboxymethyl chitosan (CMCS) were synthesized and alternatively incorporated via imine linkage into the multilayer coating in layer-by-layer (LbL) deposition. Surface plasmon resonance (SPR) technique was utilized to monitor the LbL assembly process. With increasing number of assembled bilayers, the antifouling performances against bovine serum albumin (BSA) adsorption, bacterial (S. aureus and E. coli) adhesion, and alga (Amphora coffeaeformis) attachment improved steadily. The self-polishing ability of the multilayer coatings was achieved via cleavage of pH-responsive imine linkage under acidic environments. As such, dense bacterial adhesion induced detachment of the outmost layer of the coatings. The efficacies of antifouling and antimicrobial adhesion were thus enhanced by the self-polishing ability of the multilayer coatings. Therefore, the LbL-deposited self-polishing dextran/chitosan multilayer coatings offer an environmentally friendly and sustainable alternative for combating biofouling in aquatic environments.
Domaine de référence : Antifouling
Auteur Xu Gang, Liu Peng, Pranantyo Dicky, Neoh Koon-Gee, Kang En-Tang
Année de parution : 2018.
Type de document : Article de revue.
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Eco-friendly design of superhydrophobic nano-magnetite/silicone composites for marine foul-release paints

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Résumé : Bioinspired Aryldiazonium Carbohydrate Coatings: Reduced Adhesion of Foulants at Polymer and Stainless Steel Surfaces in a Marine Environment
Domaine de référence : Antifouling
Année de parution : 2017.
Type de document : Page Web.
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Ce projet est financé par le Fonds Européen de Développement Régional, la Région Normandie et le Conseil Départemental de la Manche.