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Performance prediction of loop-type wind turbine

Résumé : An experimental and analytical method to evaluate the performance of a loop-type wind turbine generator is presented. The loop-type wind turbine is a horizontal axis wind turbine with a different shaped blade. A computational fluid dynamics analysis and experimental studies were conducted in this study to validate the performance of the computational fluid dynamics method, when compared with the experimental results obtained for a 1/15 scale model of a 3 kW wind turbine. Furthermore, the performance of a full sized wind turbine is predicted. The computational fluid dynamics analysis revealed a sufficiently large magnitude of external flow field, indicating that no factor influences the flow other than the turbine. However, the experimental results indicated that the wall surface of the wind tunnel significantly affects the flow, due to the limited cross-sectional size of the wind tunnel used in the tunnel test. The turbine power is overestimated when the blockage ratio is high; thus, the results must be corrected by defining the appropriate blockage factor (the factor that corrects the blockage ratio). The turbine performance was corrected using the Bahaj method. The simulation results showed good agreement with the experimental results. The performance of an actual 3 kW wind turbine was also predicted by computational fluid dynamics.
Domaine de référence : EMR
Auteur Jeon Wonyoung, Park Jeanho, Lee Seungro, Jung Youngguan, Kim Yeesock, Seo Youngjin
Année de parution : 2020.
Mots-clés : blade design, computational fluid dynamics, horizontal axis wind turbine, Loop-type wind turbine, wind energy.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

LARGE EDDY SIMULATION OF FLOW AROUND MARINE TURBINE

Résumé : Renewable energy usually refers to those natural resources of energy whose availability does not decrease with its usage. Various sources of renewable energy are there such as solar energy, wind energy, marine energy. The marine current turbine (MCT), is an exciting proposition for the extraction of tidal and marine current power. CFD simulation is being widely used in the research on marine current turbines. The present research also represents a step in this direction. Solution of incompressible unsteady Navier-Stokes (N-S) equations is required in the numerical simulation of flow around MCT. Large eddy simulation (LES) has been opted which fully resolves the energetic turbulent flow structures and models only the sub-grid scale turbulence. IB method has been used to enforce the boundary conditions on complex geometry. Due to computational limitations we have been able to perform only a coarse grid LES of the marine turbine for specific operating conditions. Nevertheless, the results provide insights into the flow structures around the marine turbine. Analysis shows that the effect of vorticity diminishes after 11R from the turbine rotor blade. However, the velocity deficit region remains until the end of the domain used in our simulations which is 10D distance downstream of the rotor blades.
Domaine de référence : EMR
Auteur Maity Ankita, Singh Krishna Mohan
Année de parution : 202.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Coupled three-dimensional dynamics model of multi-component mooring line for motion analysis of floating offshore structure

Résumé : A coupled dynamics model of multi-component mooring line is proposed to analyze the motion of a floating offshore structure. The model is developed by extending three-dimensional lumped mass method allowing the motion of segment connection points and including an anchor and clump weights. It offers analysis on simultaneous interlocking-segment line motions to solve three-dimensional dynamic responses of a multi-component mooring line. The model integrates hydrodynamic loads, line-seabed interaction, elasticity, current effect, and dragging anchor motions. It is then coupled with a ship-type floating offshore structure and validated by comparing with equivalent model based on a conventional numerical method. Comparison against two-dimensional model is also established. Finally, coupled motion analysis of the floating structure moored by multi-leg with multi-component mooring lines in realistic operations are conducted by considering actual environmental loads. The impact of the presented dynamics model on the evaluation of the response of the floating structure and mooring line tension are investigated. The results conclude that the model can successfully provide the realistic prediction of the motion of the floating structure. Farther, this paper found out that three-dimensional mooring line treatment needs to be considered since lateral mooring line motion has considerable impact on mooring line tension.
Domaine de référence : EMR
Auteur Hermawan Yuda Apri, Furukawa Yoshitaka
Année de parution : 2020.
Mots-clés : Coupled analysis, Mooring line dynamics, Multi-component mooring line, Three-dimensional dynamics model.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Review on Tidal Energy Technologies and Research Subjects

Résumé : Tidal current power is one of the promising and reliable renewable energies with the advantage of continuous and predictable resource. It can make stable electricity regardless of weather conditions or seasons all year around. The required technologies for tidal current power in the ocean have been developed for years and now recognized that it could be commercialized after intensive field tests and successful demonstrations. There are several tidal farm development projects in the world, such as the MeyGen project in UK with its commercialization at hand. However, various research subjects in the tidal current energy field are seeking improvements and industrialization of tidal current power in terms of economy and technical reliability. This paper introduces the resource assessment procedure of tidal energy that has been applied in Korea coastal regions. The key research subjects for tidal current power together with the interaction effect of multi-arrangement is described. Also, this paper is to introduce the research output of each subject such as turbine design, experimental validation, turbine interaction and wake, multi-array module, FSI (fluid-structure interaction), and duct application.
Domaine de référence : EMR
Auteur Jo Chul Hee, Hwang Su Jin
Année de parution : 2020.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Monitoring and modeling of environmental load considering dependence and its impact on the failure probability

Résumé : Extreme weather conditions put heavy environmental loads on systems and may cause catastrophic failure. Classification societies such as Lloyd's Register, DNV GL and the American Bureau of Shipping recommend methods for environmental load calculations. These methods do not consider dependencies among parameters when calculating environmental loads. This paper proposes a novel methodology to consider the copula-based bivariate failure function to evaluate the dependence structure of parameters and minimize uncertainty in load calculations. It also presents a robust operational failure assessment model that considers real-time environmental parameters along with their dependencies. The proposed methodology and models are tested on a semi-submersible mobile unit (SMU). The failure probability corresponding to the wind and wave loads imposed on the SMU is calculated using a physical reliability model and Bayesian network. The copula-based bivariate failure function defines the dependence using the parameters δ, which are estimated using maximum likelihood estimation. A detailed case study illustrates the advantage of the proposed methodology. The proposed method is of vital significance to developing a safe operating envelope for offshore assets likely to face extreme weather conditions.
Domaine de référence : EMR
Auteur Fu Jinjie, Khan Faisal
Année de parution : 2020.
Mots-clés : Copula function, Dependence, Environmental loads, Maximum likelihood estimation, Operational failure.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

An overview of maintenance management strategies for corroded steel structures in extreme marine environments

Résumé : Maintenance is playing an important role in integrity management of marine assets such as ship structures, offshore renewable energy platforms and subsea oil and gas facilities. The service life of marine assets is heavily influenced by the involvement of numerous material degradation processes (such as fatigue cracking, corrosion and pitting) as well as environmental stresses that vary with geographic locations and climatic factors. The composition of seawater constituents (e.g. dissolved oxygen, salinity, temperature content, etc.) is one of the major influencing factors in degradation of marine assets. Improving the efficiency and effectiveness of maintenance management strategies can have a significant impact on operational availability and reliability of marine assets. Many research studies have been conducted over the past few decades to predict the degradation behaviour of marine structures operating under different environmental conditions. The utilisation of structural degradation data – particularly on marine corrosion – can be very useful in developing a reliable, risk-free and cost-effective maintenance strategy. This paper presents an overview of the state-of-the-art and future trends in asset maintenance management strategies applied to corroded steel structures in extreme marine environments. The corrosion prediction models as well as industry best practices on maintenance of marine steel structures are extensively reviewed and analysed. Furthermore, some applications of advanced technologies such as computerized maintenance management system (CMMS), artificial intelligence (AI) and Bayesian network (BN) are discussed. Our review reveals that there are significant variations in corrosion behaviour of marine steel structures and their industrial maintenance practices from one climatic condition to another. This has been found to be largely attributed to variation in seawater composition/characteristics and their complex mutual relationships.
Domaine de référence : Biocorrosion , EMR
Auteur Abbas Muntazir, Shafiee Mahmood
Année de parution : 2020.
Mots-clés : Degradation, Extreme climatic conditions, Maintenance management, Marine corrosion, Steel structures.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Vibration and noise studies on wind turbine generator for reduction of vibrations and noise

Résumé : Purpose Wind power is the one of best natural resources to meet the demands of electricity in India. In this regard, one of engineering college in Visakhapatnam has procured wind turbine generators of 200 kWp and got these installed on the rooftop of the college buildings for research and power generation. After starting the mills, huge vibrations were experienced by the staff and students in the laboratories and classrooms. So, the purpose of this paper is to carry out vibration and noise studies on wind turbine generator to identify the problem for high vibrations and suggest a novel method for vibration reduction. Design/methodology/approach Experimental vibration and natural frequency investigations are carried when wind velocity around 6.0 m/s using frequency analyzer, impact hammer, condenser microphone and accelerometer. An attempt is made to reduce the vibration and noise level of wind turbine generator by inserting a steel coil spring of 300 mm length having 20 turns in series with turnbuckle D shackle assembly, which is used to connect the wind turbine generator to the hook mounted on slab. Findings A high vibration velocity of 9.9 mm/s was observed on at base frame of wind turbine generator. The natural frequencies of hook and slab are observed in between 15 to 20 Hz from the natural frequency test. A high noise of 94.67 dBA is observed at a distance of 1 m from the base of wind turbine generator along the rotational axis of rotor. After modification to the baseline, WTG the vibration and noise levels are reduced to 4.8 mm/sec and 77.76 dBA, respectively. Originality/value This is the first time to study the huge vibrations generated in wind turbine generators installed on the rooftop of the college. Developed a novel methodology to reduce the vibrations by inserting a steel coil springs in turnbuckle D shackle assembly of wind turbine generators. After modification, wind turbine generator are running successfully without any high vibrations.
Domaine de référence : EMR
Auteur Shinagam Ramakrishna, Ajay Guntaka, Patta Lokanadham, Gandam Anand Siva
Année de parution : 2020.
Mots-clés : Condenser microphone, Forced frequency analyzer, Impact hammer, Natural frequency analysis, Noise analysis, Steel coil spring, Vibration analysis, Wind turbine generators.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

The hydrodynamic performance of a tidal-stream turbine in shear flow

Résumé : Tidal-stream turbines spend most of time in a shear flow environment, which leads to non-uniformity effect in stream vertical profile. To better understanding of such effect on tidal-stream turbine performance, the hydrodynamic performance and comparison between a bare turbine and a diffuser-augmented turbine under shear flow condition were numerically investigated. To closer to the real working environment of tidal-stream turbine, three major factors influence on hydrodynamic performance including flow shear rates, yaw angle and arrangement rule in array were discussed in detail. It is found that the different shear rate of flow will result in power and axis thrust slightly amplitude comparing with the uniform flow, and a diffuser turbine will further amplify this effect comparing with a bare turbine. The greater the yaw angle is, the more power and axis thrust is reduced. Additionally, there are “Advantageous Interaction” and “Disadvantage Interaction” in the wake effect on the energy extraction performance in the turbine array. The output power for each case is relatively concentrated at lower tip speed ratio (TSR) and divergent at higher TSR. Furthermore, each turbine in array operating at near 2D flow distance and relative deviation angle of 45° reaches its maximum CP.
Domaine de référence : EMR
Auteur Ke Song, Wen-Quan Wang, Yan Yan
Année de parution : 2020.
Mots-clés : Computational fluid dynamic, Shear flow, Tidal-stream turbine, Turbine array, Yaw angle.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Fatigue of improved polyamide mooring ropes for floating wind turbines

Résumé : This paper describes a study of the fatigue characterization of polyamide mooring ropes for floating wind turbines. Under some conditions polyester ropes, which are favoured for offshore oil and gas platform station-keeping, are too stiff for wind turbine moorings, and polyamide may be a suitable alternative. While early studies on fatigue of braided nylon ropes showed very short lifetimes some recent results have indicated that it is possible to significantly enhance lifetime by modifying rope construction and improving fibre coatings. In this paper yarn-on-yarn abrasion testing is used first to evaluate a new yarn coating. Significant lifetime enhancement was noted, so fatigue testing of ropes was then performed. Results confirm that excellent fatigue lifetimes can be achieved, superior to those for steel chain. Finally, failed yarn and rope samples were examined by microscopy, in order to improve understanding of the fatigue mechanisms leading to failure.
Domaine de référence : EMR
Auteur Chevillotte Yoan, Marco Yann, Bles Guilhem, Devos Karel, Keryer Mathieu, Arhant Maël, Davies Peter
Année de parution : 2020.
Mots-clés : Fatigue, Floating wind turbine, Mooring, Nylon, Rope, Water.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Concept and performance of a novel wave energy converter : Variable Aperture Point-Absorber (VAPA)

Résumé : Ocean waves are a huge and largely untapped resource of green energy. In order to extract energy from waves, a novel wave energy converter (WEC) consisting of a floating, hollow cylinder capped by a roof with a variable aperture is presented in this paper. The power take-off (PTO) system is composed of a linear generator attached to the seabed, driven by the heave motion of the floating cylinder through a tether line. The air pressure within the cylinder can be modified by adjusting the roof aperture. The hydrodynamic characteristics of this WEC are investigated through an analytical model based on potential flow theory, in which the wave diffraction/radiation problems are coupled with the air pressure fluctuation and PTO system. Analytical expressions are derived for the maximum power absorbed by the WEC under different optimization principles, revolving around the PTO damping, roof aperture damping and non-negative mooring stiffness. We find that the best power absorption is obtained when the aperture is either completely open or entirely closed, depending on the wave conditions. Intermediate values of the aperture are useful to minimize the heave motion and thus ensure survivability under extreme sea states.
Domaine de référence : EMR
Auteur Zheng Siming, Zhang Yongliang, Iglesias Gregorio
Année de parution : 2020.
Mots-clés : Marine Renewable Energy, Ocean energy, Point-absorber, Wave energy converter, Wave power.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Maximum efficiency point tracking for an ocean thermal energy harvesting system

Résumé : Limited energy is the most critical factor that restricts the persistent presence of underwater vehicles in the oceans; thus, harvesting the ocean’s thermal energy that is stored in the water column between the sea surface and deep water is a particularly promising solution for the current power shortage. This paper has designed a new ocean thermal energy conversion system which using phase change material as energy storage medium, and proposed a novel maximum efficiency point tracking (MEPT) method for energy conversion. This new method, which is integrated with a radial basis function neural network (RBFNN), particle swarm optimization (PSO) and the proportion integration differentiation (PID) control method, could effectively improve the efficiency of energy conversion. Compared with the power generation system that does not use the MEPT method, experimental results show that the proposed method can improve the efficiency of the power generation from less than 19.05% to more than 34.3% and has higher stability (using this method: the efficiency changes from 34.3%-34.7%; without using this method: the efficiency changes from 13.56% -19.05%) when the load changes. This novel method can be used in many conditions, especially when the mathematical model of the generation system is unknown or researchers want to use fewer sensors for maximum efficiency point tracking.
Domaine de référence : EMR
Auteur Xia Qingchao, Chen Yanhu, Yang Canjun, Chen Bingzhe, Muhammad Gul, Ma Xiaoxia
Année de parution : 2020.
Mots-clés : artificial neural network, current control, fixed initial energy, hydraulic power generation system, maximum efficiency point tracking (MEPT), ocean thermal energy.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Analysis of a Gyroscopic-Stabilized Floating Offshore Hybrid Wind-Wave Platform

Résumé : Hybrid platforms are a promising architecture in innovative energy scenario for the minimization of the cost of offshore marine renewable installations and for reducing the variability of the power output. This article models and discusses the installation of a 5 MW wind turbine on a floating platform designed by Fincantieri and equipped with gyroscopic stabilization. Gyros will provide platform stabilization by damping the wave and wind induced motion on the floater and at the same time producing extra power. A reference site on the Shetland Island with particular harsh weather is chosen. Results show how the gyro can produce a considerable amount of power in moderate and medium climate conditions together with a considerable stabilization of the platform in terms of pitching angle and nacelle acceleration.
Domaine de référence : EMR
Auteur Attanasio Valentino, Bracco Giovanni, Bonfanti Mauro, Sirigu Sergej Antonello, Fontana Marco, Fenu Beatrice, Mattiazzo Giuliana
Année de parution : 2020.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Cooling a wind turbine generator

Résumé : Cooling a wind turbine generator It is described an arrangement (100, 200) for cooling a generator mounted in a nacelle of a wind turbine, the arrangement comprising: a cooling air inlet (105) at an outer wall (1β7) of the nacelle (103) for introducing cooling air (109) into a space region (111) inside the nacelle; an inlet fan (113) downstream the cooling air inlet (105) configured to pressurize the introduced cooling air within the space region (111); a filter system (115) downstream the inlet fan (113) and separating the space region (111) from another space region (117) inside the nacelle (103), the other space (117) region being in communication with generator portions (119) to be cooled; a duct system (129) adapted to guide a portion (130) of cooling air (132) heated by exchange of heat from the generator portions to the cooling air into the space region (111).
Domaine de référence : EMR
Auteur Soerensen Peter Hessellund
Année de parution : 2020.
Mots-clés : arrangement, cooling air, generator, nacelle, space region.
Type de document : Brevet.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Modelling Offshore Wind Farm Operation and Maintenance : The Benefits of Condition Monitoring

Résumé : A wind turbine is of course far more complicated than just a tower topped with a big fan, especially for the offshore ones. Wind energy as a green energy resource with zero fuel requirements, and thus no processing waste, has been assuming an increasingly important role in energy generation. Offshore wind farms with their steady output and low sensual impact have been gradually accepted by the public and authorities. Once built, the only cost for a wind farm is the operation and maintenance cost. Therefore, the question of how to reduce the failure rate and the operation and maintenance costs, and make offshore wind energy cheaper, is particularly pertinent, and is discussed in great detail here.This book details the various aspects of wind energy, and is accessible to the lay reader without any specialist knowledge. It explores the numerous concepts associated with offshore wind farm operation and maintenance with condition monitoring system, and vividly presents the the basics of wind energy, augmenting this with a large amount of valuable real wind farm case studies.
Domaine de référence : EMR
Auteur Yu Xi
Année de parution : 2020.
Mots-clés : Technology & Engineering / Power Resources / Alternative & Renewable, Technology & Engineering / Power Resources / General.
Type de document : Livre.
Source : Cambridge Scholars Publishing
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Experimental study of temperature erosion tests on bidirectional coated and uncoated composites materials

Résumé : In this research work, temperature erosion wear tests, on composites materials (carbon fiberand glass fiber), were carried out. The tests were made on uncoated and coated materials using a polyester resin (Gelcoat), which is used to protect the leading edge of wind turbine blades against the weather and UV rays and is of interest, in this study, to know the behaviour of this coating subjected to hard particles erosion. The tests were performed at 50°C, in order to simulate de extreme temperature in the coast of Oaxaca, Mexico, where some wind turbines are installed using blades made of fiberglass coated with gelcoat. Erosion tests were performed in a platform that was developed from the ASTM G76 standard. The rectangular samples had 25 x 18 mm and thickness of 4 mm. Sea sand from coast of Oaxaca was utilized as erosive particle. Three different impact angles were used 75°, 85° and 90°. The particle velocity was adjusted at 12 m/s. To determine the mass loss, the samples were weighed before the test and reweighed every 2 minutes to measure the amount of mass loss until complete the 6 minutes of the test. In order to identify the wear mechanisms, Scanning Electron Microscopy was used. The average roughness (Ra) and profiles of the samples tested were determined with a 3D optical profilometer. The results showed that Carbon fiber composite material had 3 times more resistance to erosive wear than fiberglass.
Domaine de référence : EMR
Auteur Mendoza Mendoza Jesus Cornelio, Vera Cardenas Edgar Ernesto, Pérez Armando Irvin Martínez, Ledesma Ledesma Saul, Vite Torres Manuel
Année de parution : 2020.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

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

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

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

Aerodynamic and Hydrodynamic Study of Offshore Wind Turbine Foundation

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

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

Domaine de référence : EMR
Auteur McShane Bill
Année de parution : 2019.
Type de document : Article de revue.
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Structural Design and Analysis of a 5MW Offshore Wind Turbine Blades Under Critical Aerodynamic Loads

Résumé : The rise in fuel prices and the depletion of fossil resources; due to the demand created by rapid industrial growth; have pushed states to resort to renewable energies, notably Offshore wind turbine (OWT). Our study aims to propose a structural design for the development of a composite blade of 48m length for an offshore wind turbine. The design loads were determined from various loading cases indicated in the international specifications for the wind energy conversion system. Parametric studies are performed with the ABAQUS finite element analysis software to determine and propose a particular structure configuration, which can effectively withstand extreme load conditions.
Domaine de référence : EMR
Auteur Boudounit H, Tarfaoui M, Saifaoui D
Année de parution : 2019.
Type de document : Article de revue.
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Editorial : Advanced research on offshore structures and foundation design : part 1

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

Impact of tidal turbine biofouling on turbulence and power generation

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

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

Tidal power systems : A review

Domaine de référence : EMR
Auteur Elyazid Amirouche, Kaci Ghedamsi, Djamal Aouzellag
Année de parution : 2019.
Type de document : Article de revue.
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Design Method of Jacket Foundation for Tidal Current Turbine

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


• Biocorrosion icone-flux-rss

Chemical and microbiological corrosion inhibitors used in the refinery and petrochemical industry

Résumé : For the construction of installations in refineries and petrochemical industry metal alloys are used among which steel is most popular. One of the most substantial problems of these materials is corrosion, which can cause huge financial losses, as well as causes threats to the environment and human life, therefore various methods of corrosion monitoring are used. There are many variations of corrosion that can be more or less dangerous but all are very undesirable. Corrosion can be caused by chemical compounds, but also by microorganisms such as fungi or bacteria. This type of corrosion is most commonly found in tanks with crude oil or petroleum products. The use of corrosion-resistant steel alloys is expensive, so other methods of corrosion protection are often used, the most important of which is application of protective coatings and the addition of compounds having corrosion-inhibiting properties. The use of corrosion inhibitors is a relatively cheap and effective method, which is why many compounds have been tested for corrosion inhibition, and many corrosion inhibition mechanisms have been found. Currently, very often tested and dynamically developed group of compounds are organic inhibitors, especially quaternary geminal ammonium salts. Many studies are also conducted on the use of polymer compounds as inhibitors. The goal of conducted research was to investigate the effect of compounds with corrosion inhibiting properties on the rate of both microbiological and chemical corrosion. To determine the aptitude of these compounds as corrosion inhibitor, a gravimetric method was used. In the case of study on the effect on microbiological corrosion, the added inhibitor did not show a significant effect on corrosion rate. It was different in the case of study on the effect on chemical corrosion, in which both tested inhibitors contributed to the slowdown of this process.
Domaine de référence : Biocorrosion
Auteur Banasiak Krzysztof
Année de parution : 2020.
Type de document : Thèse.
Source : Instytut Chemii
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Microbiological corrosion in the refining and petrochemical industry - preliminary laboratory tests

Résumé : Microbiological corrosion can be defined as an electrochemical process in which microorganisms facilitate the corrosion reaction of metals. This is a serious problem that can lead to damage to the installation, destruction of apparatus and reduction of process efficiency, which is associated with large economic losses. Microbiologically influenced corrosion is caused by microorganisms such as algae, lichen, fungi and bacteria. Fungus Hormoconis resinae is a huge problem of aviation fuel, sulfate-reducing bacteria form iron sulfides, which cause stress corrosion and cracking of structural materials. Iron-reducing bacteria form deposits of iron oxides and hydroxides that hide under their surface corrosion pits. Acid-producing bacteria form organic acids that are corrosive. Nitrogenous oxidizing bacteria conduct nitrification reaction that produces nitric acid. They oxidize nitrogen compounds, so they can deactivate inhibitors that have nitrogen in their structure. These microorganisms significantly contribute to corrosion. Many methods are used to prevent this form of corrosion. The most common of them are: washing the components of the installation, both physical and chemical, protective coatings, the usage of various biocides and corrosion inhibitors, e.g. quaternary ammonium compounds which field is now being dynamically developed. The purpose of the research conducted as part of the work was to check whether the inhibitor used would inhibit corrosion processes, or maybe just the opposite and would accelerate them. In order to determine the usability of corrosion inhibitor, gravimetric method was used. In the study of microbial corrosion, the added inhibitor significantly reduced the rate of this type of corrosion.
Domaine de référence : Biocorrosion
Auteur Gozdanek Marcin
Année de parution : 2020.
Type de document : Thèse.
Source : Instytut Chemii
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Two novel drugs as bio-functional inhibitors for copper performing excellent anticorrosion and antibacterial properties

Résumé : Two drugs (cefpirome, cefixime) as dual-action inhibitors could self-organize on copper surface forming bio-functional protective film, which effectively prevents copper corrosion in the picking process with an excellent performance on the resistance of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) results showed that studied drugs can self-organize on copper surface successfully forming adsorption film to protect copper. The results also indicated that N/S atoms with the lone pair electrons in the drugs donated electrons to the vacant orbital of Cu occupying the active sites of copper surface. Electrochemistry and surface morphology study revealed that the corrosion inhibition efficiency of cefixime was better than cefpirome. Furthermore, adsorption isotherm study suggested that the adsorption was spontaneous chemical and physical adsorption, obeying Langmuir adsorption.
Domaine de référence : Biocorrosion
Auteur Feng Li, Zhang Shengtao, Tao Bailong, Tan Bochuan, Xiang Bin, Tian Wei, Chen Shijin
Année de parution : 2020.
Mots-clés : Acid solution, Antibacterial, Copper, Corrosion, Microbiological corrosion.
Type de document : Article de revue.
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Microbial corrosion of initial perforation on abandoned pipelines in wet soil containing sulfate-reducing bacteria

Résumé : In this work, the microbial corrosion inside a perforation on an X52 pipeline steel was investigated in wet soil containing sulfate-reducing bacteria (SRB) by biotesting, electrochemical measurements, including open-circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization, and surface analysis techniques such as 3D topographic imaging, scanning electron microscopy and energy-dispersive x-ray spectrum. Results show that the further corrosion rate of the initial perforation on pipelines is not uniform along its depth direction, and the corrosion kinetics depends on the availability of microorganism such as SRB in the environment. In abiotic environments, the perforation close to the solution side corrodes more rapidly than that at the soil side. However, in SRB-containing environments, the corrosion kinetics is different, where the middle of perforation possesses the greatest corrosion rate, which is attributed to the microbially accelerated corrosion. There are generally more sessile SRB cell counts on the steel near the solution phase than that at the soil side. The corrosion of the perforation could be attributed to the high counts of sessile SRB cells and their starvation effect, making the SRB extract electrons directly from the steel.
Domaine de référence : Biocorrosion
Auteur Liu Hongwei, Cheng Y. Frank
Année de parution : 2020.
Mots-clés : Microbiologically influenced corrosion, Perforation, Pipelines, Soil solution, Sulfate-reducing bacteria, Wet soil.
Type de document : Article de revue.
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Microbiologically influenced corrosion of Cu by nitrate reducing marine bacterium Pseudomonas aeruginosa

Résumé : The microbiologically influenced corrosion (MIC) mechanisms of copper by Pseudomonas aeruginosa as a typical strain of nitrate reducing bacteria (NRB) was investigated in this lab study. Cu was immersed in deoxygenated LB-NO3 seawater inoculated with P. aeruginosa and incubated for 2 weeks. Results showed that this NRB caused pitting and uniform corrosion. The maximum pit depths after 7 d and 14 d in 125 mL anaerobic vials with 50 mL broth were 5.1 μm and 9.1 μm, accompanied by specific weight losses of 1.3 mg/cm2 (7 d) and 1.7 mg/cm2 (14 d), respectively. Electrochemical measurements corroborated weight loss and pit depth data trends. Experimental results indicated that extracellular electron transfer for nitrate reduction was the main MIC mechanism and ammonia secreted by P. aeruginosa could also play a role in the overall Cu corrosion process.
Domaine de référence : Biocorrosion
Auteur Pu Yanan, Dou Wenwen, Gu Tingyue, Tang Shiya, Han Xiaomei, Chen Shougang
Année de parution : 2020.
Mots-clés : Biofilm, Cu, Microbiologically influenced corrosion, Nitrate reducing bacteria, Pitting corrosion.
Type de document : Article de revue.
Exporter la référence : BibTeX | Zotero RDF | RIS (EndNote)

Studies on the Antibacterial Influence of Two Ionic Liquids and their Corrosion Inhibition Performance

Résumé : In this paper the anti-bacterial and the anti-corrosion effect of two different ionic liquids, namely 1-(2-hydroxyethyl)-3-methylimidazolinium chloride ([OH-EMIm]Cl) and 1-ethyl-3-methyleimidazolinium chloride ([EMIm]Cl) was demonstrated. The results revealed that the corrosion inhibition influence of the ionic liquid [OH-EMIm]Cl is higher than that of the ionic liquid [EMIm]Cl. Furthermore, the ionic liquid [OH-EMIm]Cl showed better biocidal influence compared with the ionic liquid [EMIm]Cl. This indicates the synergistic effect due to the incorporation of the hydroxyl group into the side chain of the imidazolium cation leading to enhanced antibacterial and anticorrosion effect.
Domaine de référence : Biocorrosion
Auteur Shehata Mohamed F., El-Shamy Ashraf M., Zohdy Khaled M., Sherif El-Sayed M., Zein El Abedin Sherif
Année de parution : 2020.
Mots-clés : biocide, corrosion, inhibition, ionic liquids, microbial corrosion.
Type de document : Article de revue.
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Biofilm Formation Plays a Crucial Rule in the Initial Step of Carbon Steel Corrosion in Air and Water Environments

Résumé : In this study, we examined the relationship between the effect of a zinc coating on protecting carbon steel against biofilm formation in both air and water environments. SS400 carbon steel coupons were covered with a zinc thermal spray coating or copper thermal spray coating. Coated coupons were exposed to either air or water conditions. Following exposure, the surface conditions of each coupon were observed using optical microscopy, and quantitatively analyzed using an x-ray fluorescence analyzer. Debris on the surface of the coupons was used for biofilm analysis including crystal violet staining for quantification, Raman spectroscopic analysis for qualification, and microbiome analysis. The results showed that the zinc thermal spray coating significantly inhibited iron corrosion as well as biofilm formation in both air and water environments. The copper thermal spray coating, however, accelerated iron corrosion in both air and water environments, but accelerated biofilm formation only in a water environment. microbially-influenced-corrosion-related bacteria were barely detected on any coupons, whereas biofilms were detected on all coupons. To summarize these results, electrochemical corrosion is dominant in an air environment and microbially influenced corrosion is strongly involved in water corrosion. Additionally, biofilm formation plays a crucial rule in carbon steel corrosion in both air and water, even though microbially-influenced-corrosion-related bacteria are barely involved in this corrosion.
Domaine de référence : Biocorrosion
Auteur Ogawa Akiko, Takakura Keito, Hirai Nobumitsu, Kanematsu Hideyuki, Kuroda Daisuke, Kougo Takeshi, Sano Katsuhiko, Terada Satoshi
Année de parution : 2020.
Mots-clés : copper, corrosion, steel, thermal spray, zinc.
Type de document : Article de revue.
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Extreme value modeling of localized internal corrosion in unpiggable pipelines

Résumé : Localized internal corrosion is one of the main failure mechanisms of energy pipelines. Microbiologically influenced corrosion (MIC) is a major contributor to internal corrosion in pipelines. Existing research uses extreme value analysis to fit extreme value distributions from data collected through either inspection or experiment to predict localized corrosion. The paper introduces an extreme value model to estimate the depth of localized internal corrosion considering MIC for unpiggable pipelines where inspection data is not available. The depth of material loss is estimated though a combination of corrosion analysis and extreme value modeling. A case study is provided to illustrate the proposed model. The application of a probabilistic approach supports risk-based inspection and maintenance planning for pipelines subject to internal corrosion.
Domaine de référence : Biocorrosion
Auteur Melo Carlos, Dann Markus, Hugo Ronald J., Janeta Alberto
Année de parution : 2020.
Mots-clés : Extreme value modeling, Integrity, Microbiologically influenced corrosion, Pitting corrosion, Risk, Unpiggable pipelines.
Type de document : Article de revue.
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e-book-Advances-and-Trends-in-Biotechnology-and-Genetics-Vol1.pdf

Domaine de référence : Biocorrosion
Année de parution : 0.
Type de document : Pièce jointe.
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Effect of Tidal Cycles on Bacterial Biofilm Formation and Biocorrosion of Stainless Steel AISI 316L

Résumé : The effects of tidal cycles associated with the water level on the biocorrosion of stainless steel AISI 316L were studied. Steel coupons were exposed to different conditions of immersion in mesocosms fed by fresh seawater either continuously or in accordance with the periodicity of natural tides. After 5 and 15 weeks, all coupons were found to have undergone ennoblement associated with the formation of a biofilm. Analysis of the composition of the bacterial community using denaturing gradient gel electrophoresis (DGGE) revealed differences in the biological succession. After 15 weeks, exposure to the simulated tidal conditions resulted in biofilms with lesser bacterial richness; the corresponding rate of corrosion, as determined by weight loss, was about 40 times lower compared to the case for the continuous exposure to seawater. Phylogenetic analysis of selected DGGE bands and the inspection of biofilm morphologies revealed that the faster rate of corrosion was associated with the presence of iron-oxidizing Zetaproteobacteria and eukaryotic photosynthetic microorganisms. On the other hand, intermittent exposure to seawater resulted in the succession of microorganisms resistant to the stress associated with sudden environmental changes, which was associated with a low rate of corrosion.
Domaine de référence : Biocorrosion
Auteur Daille Leslie K., Aguirre Javiera, Fischer Diego, Galarce Carlos, Armijo Francisco, Pizarro Gonzalo E., Walczak Magdalena, De la Iglesia Rodrigo, Vargas Ignacio T.
Année de parution : 2020.
Mots-clés : microbiological corrosion, polarization, SEM, stainless steel, weight loss.
Type de document : Article de revue.
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Searching for bacteria in sticky situations : Methods for investigating bacterial survival at solid-air interfaces involving Wyoming MX-80 bentonite

Résumé : Effective removal of prokaryotic cells from clay interfaces such as bentonite is essential for quantitative assessment of microbial communities, considering that strong bentonite clay-DNA and –RNA complexes challenge the use of molecular-based techniques. In this study, aerobic bacteria were isolated from Wyoming MX-80 bentonite and sequenced for identification (16S rRNA). A glass-bentonite substrate and sterile bentonite powder were inoculated with Arthrobacter sp. (isolated from bentonite) to test cell removal efficiency using sonication and vortexing. Manipulation of pH (pH 7 versus pH 9) did not affect cell removal efficiency, while changes in temperature within limits (15–37 °C) did affect cell removal efficiency. To evaluate microbial survival during desiccation, bacterial isolates were inoculated onto glass and bentonite-covered glass coverslip substrates, and particulate bentonite. Substrates were desiccated, and cells were removed by vortexing at different time points over 31 days. Abundance of viable cells followed a first-order rate of decrease. Vegetative desiccation-tolerant Arthrobacter sp. isolates from bentonite clay had lower loss of viable, culturable cells (0.07 d−1 to 0.89 d−1) than did a Bacillus sp. isolate (>1 d−1) or a Pseudomonas stutzeri isolate (0.79 to >1 d−1), suggesting Arthrobacter sp. may be more tolerant of these prolonged periods of desiccation on the bentonite-air interface. Tolerance to matric stress by microorganisms varies depending on the cellular adaptation of the target species, the physical and chemical properties of the given solid-air environment, as well as the employed population and community-based survival mechanisms.
Domaine de référence : Biocorrosion
Auteur Pashang Rosha, Laursen Andrew E.
Année de parution : 2020.
Mots-clés : Adhesion, Cell removal, Clay interface, Desiccation tolerance, Nuclear waste storage, Nutrient starvation, Vegetative cell survival.
Type de document : Article de revue.
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Surface conditions for microcosm development and proliferation of SRB on steel with cathodic corrosion protection

Résumé : Steel components used in civil infrastructure are susceptible to microbiologically influenced corrosion (MIC) in marine environments due to the interactions between the metal and its environment with varying water quality parameters (chemical and biological). Sulfate-reducing bacteria (SRB) has been associated with MIC by a cathodic depolarization mechanism due to the reaction of surface hydrogen. Recent findings at a Florida bridge showed severe localized corrosion associated with microbial activity and heavy marine fouling of the submerged steel piles. Cathodic protection can be applied to control the corrosion of steel; however, the mitigation may be impaired by the microbial activity and marine fouling. The objective of this work was to explore reduction reactions on cathodically polarized steel surfaces and evaluate the influence of cathodic polarization on sulfate reduction reaction. It was of interest to characterize the reduction reaction in crevices representative of different physical properties of the marine foulers where SRB can be supported. Field testing was conducted to differentiate the cathodic protection currents that develop in the presence of microorganisms under the layer of marine fouling in natural environments. Laboratory tests were conducted to elucidate the cathodic reactions by potentiostatic cathodic polarization of steel specimens in solutions inoculated with SRB. Field testing showed that proliferation of the bacteria was not inhibited in the presence of cathodic polarization at about −1000 mVCSE and corrosion continued in the localized regions under fouling encrustation. The larger cumulative charge relating to the apparent sulfate reduction by SRB corresponded to higher levels of cathodic polarization. Sulfate reduction by SRB can be a significant contributor to the electrochemical process for steel corrosion with cathodic polarization. For the porous crevice environments, large cathodic currents and high sulfate reduction coincided with the development of sustained SRB growth.
Domaine de référence : Biocorrosion
Auteur Permeh Samanbar, Lau Kingsley, Tansel Berrin, Duncan Matthew
Année de parution : 2020.
Mots-clés : Cathodic protection, Marine fouling, Microbiologically influenced corrosion, Potentiostatic polarization, Sulfate-reducing bacteria.
Type de document : Article de revue.
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Evaluation and Optimization of Corrosion Inhibitor System

Résumé : By combining two methods of weightlessness and electrochemistry, the corrosion inhibitors have been selected and optimized. The orthogonal experiment has been carried out to optimize the inhibitor’s performance. The range analysis results indicated that corrosion inhibition performance of optimized corrosion inhibitor (HZ-1) has been improved remarkably. The corrosion inhibition rate can reach 94.66% with lower corrosion current density. The optimum concentration of HZ-1 is 90 mg/L and working temperature is 80~100℃. Its site application shows that the inhibitor also has remarkable corrosion inhibition effect, the concentration of iron ions is decreases, and the period of pumping wells has been prolonged significantly.
Domaine de référence : Biocorrosion
Auteur Yun Liu, Qingzhen Du, Wei Xiong, Yanfang Gao, Fang Shang, Wei Zhang, Gangliang Li
Année de parution : 2020.
Type de document : Article de revue.
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Non-contact electrochemical evaluation of biofilms

Résumé : Here, we demonstrate a non-contact technique for electrochemical evaluation of biofilms on surfaces in relation to corrosion. Electrochemical impedance spectrometry was employed, incorporating flat patterned electrodes positioned over the surfaces of aluminum and glass with and without biofilms. Signal communication from the working electrode to the counter electrode followed electric field lines passing tangentially through the biofilms. Electrochemical impedance parameters that were evaluated included complex impedance, phase angle, imaginary (out of phase) conductivity and Cole–Cole plots with a corresponding equivalent circuit. Changes in the impedance properties due to the presence of biofilms were monitored and correlated through microbiological, chemical and electrochemical assays. Impedance parameters associated with microbial activity correlated with biofilms on aluminum and glass surfaces. This technical approach provides impedance information about the biofilm without the signal traveling through the underlying conductive media or disrupting the biofilm. In this way, biological contributions to surface fouling can be evaluated with minimal contribution from the inorganic surface under the biofilm. In addition, this technique can be used to monitor biofilms on electrochemically inert surfaces as well as electrically conductive surfaces.
Domaine de référence : Biocorrosion
Auteur Turick Charles E., Colon-Mercado Hector, Bagwell Christopher E., Greenway Scott D., Amoroso Jake W.
Année de parution : 2020.
Type de document : Article de revue.
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An induced corrosion inhibition of X80 steel by using marine bacterium Marinobacter salsuginis

Résumé : The corrosion behaviour of X80 pipeline steel was studied in a simulated marine environment inoculated with marine bacterium Marinobacter salsuginis. The electrochemical results showed that the increase in linear polarization resistance, charge transfer resistance, and the decrease in corrosion current density of the X80 pipeline steel immersed in the biotic medium indicated its high corrosion resistance compared to those in the abiotic medium. Surface morphological techniques including scanning electron microscopy, confocal laser scanning microscopy and live/dead cells staining were employed to observe the biofilm morphology and bacterial viability after different immersion times. X-ray photoelectron spectroscopy was used to analyse the oxides film formed on the steel surface. The obtained results indicated that the corrosion inhibition efficiency was obviously higher in the biotic medium compared to that in the abiotic medium. The high corrosion resistance of X80 steel in biotic medium was attributed to the formation of biofilm and the development of extracellular polymeric substances (EPS) layer on its surface.
Domaine de référence : Biocorrosion
Auteur Khan M. Saleem, Yang Chunguang, Zhao Ying, Pan Haobo, Zhao Jinlong, Shahzad M. Babar, Kolawole Sharafadeen Kunle, Ullah Ihsan, Yang Ke
Année de parution : 2020.
Mots-clés : Corrosion inhibition, Marine environment, X80 steel.
Type de document : Article de revue.
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Sulfide ions-induced release of biocides from a metal-phenolic supramolecular film fabricated on aluminum for inhibition of microbially influenced corrosion

Résumé : Herein, we fabricate a novel metal-phenolic supramolecular film on aluminium, which can control release of loaded biocides when S2− concentration is higher than 10 mM or in sulfate reducing bacteria (SRB) environment with a long incubation period. The protection effect of the film on microbially influenced corrosion (MIC) induced by SRB is analyzed with fluorescence microscopy and electrochemical measurement. A novel microbiological corrosion protection mechanism is proposed based on its effective roles to suppress SRB settlement and insulate corrosive medium. The intelligent film maintains a longtime antibacterial behavior owing to its S2--responsive character, which enhances the microbiological corrosion resistance.
Domaine de référence : Biocorrosion
Auteur Cai Haoyuan, Wang Peng, Chen Xiaotong, Wang Yu, Zhang Dun
Année de parution : 2020.
Mots-clés : Aluminum, Microbially influenced corrosion, Microbiological corrosion protection, S-responsive, Sulfate reducing bacteria.
Type de document : Article de revue.
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Measurement techniques for microbial corrosion assessment

Domaine de référence : Biocorrosion
Auteur Iannucci Leonardo
Année de parution : 2019.
Type de document : Article de revue.
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Corrosion of Carbon Steel in Anoxic Sulphide Solutions

Résumé : Pipeline coatings and cathodic protection of pipelines can fail leading to exposure of the underlying steel substrate to aggressive environmental conditions. In Canada, these conditions are typically slightly alkaline and can contain microbially-produced sulphide. This study investigates the acceleration of steel corrosion in the presence of sulphide including when the steel is already covered by oxides, oxyhydroxides and siderite. Electrochemical responses (corrosion potential and polarization resistance) were monitored for up to 120 days, while simultaneously monitoring the film composition and morphology by Raman spectroscopy and scanning electron microscopy, respectively. In the absence of a preformed oxide, the initially formed mackinawite underwent anoxic aging to yield greigite and pyrite. When conversion of a preformed oxide was involved only mackinawite was observed.
Domaine de référence : Biocorrosion
Auteur Goldman Maxwell, Noel James, Shoesmith David
Année de parution : 2020.
Type de document : Article de revue.
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An overview of maintenance management strategies for corroded steel structures in extreme marine environments

Résumé : Maintenance is playing an important role in integrity management of marine assets such as ship structures, offshore renewable energy platforms and subsea oil and gas facilities. The service life of marine assets is heavily influenced by the involvement of numerous material degradation processes (such as fatigue cracking, corrosion and pitting) as well as environmental stresses that vary with geographic locations and climatic factors. The composition of seawater constituents (e.g. dissolved oxygen, salinity, temperature content, etc.) is one of the major influencing factors in degradation of marine assets. Improving the efficiency and effectiveness of maintenance management strategies can have a significant impact on operational availability and reliability of marine assets. Many research studies have been conducted over the past few decades to predict the degradation behaviour of marine structures operating under different environmental conditions. The utilisation of structural degradation data – particularly on marine corrosion – can be very useful in developing a reliable, risk-free and cost-effective maintenance strategy. This paper presents an overview of the state-of-the-art and future trends in asset maintenance management strategies applied to corroded steel structures in extreme marine environments. The corrosion prediction models as well as industry best practices on maintenance of marine steel structures are extensively reviewed and analysed. Furthermore, some applications of advanced technologies such as computerized maintenance management system (CMMS), artificial intelligence (AI) and Bayesian network (BN) are discussed. Our review reveals that there are significant variations in corrosion behaviour of marine steel structures and their industrial maintenance practices from one climatic condition to another. This has been found to be largely attributed to variation in seawater composition/characteristics and their complex mutual relationships.
Domaine de référence : Biocorrosion , EMR
Auteur Abbas Muntazir, Shafiee Mahmood
Année de parution : 2020.
Mots-clés : Degradation, Extreme climatic conditions, Maintenance management, Marine corrosion, Steel structures.
Type de document : Article de revue.
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Biogenic corrosion inhibitor on mild steel protection in concentrated HCl medium

Résumé : Turbinaria ornata (TO) extract was tested as green corrosion inhibitor on mild steel (MS) coupons in conc. HCl medium with an efficiency of 100% at 25 g l−1 during 5 min exposure. Antibacterial efficacy performed against 16 S rDNA identified marine biofilming bacteria (MBB) and human pathogenic bacteria (HPB). Maximum inhibition growth was 16 mm on MBB observed in Bacillus megaterium (MBF14 - AB894827) and 20 mm on HPB in Escherichia coli (B5 - NCIM 2931). Similarly, minimum of 10 mm on MBB witnessed in Pseudomonas sp., (MBF9 - AB894829). Toxicity studies proved 50.0% LC50 at 500 μg ml−1 in 24 hrs, whereas Balanus amphitrite resulted in 100% mortality within 12 hrs. Results including weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy, FT-IR and GC-MS confirm 10-Octadecaonic acid as a major corrosion inhibitor from T. ornata and is discovered as a novel antifoulant. Anticorrosion formulation will become available soon.
Domaine de référence : Biocorrosion
Auteur Krishnan Muthukumar, Subramanian Harinee, Dahms Hans-Uwe, Sivanandham Vignesh, Seeni Palanichamy, Gopalan Subramanian, Mahalingam Ashok, Rathinam Arthur James
Année de parution : 2018.
Type de document : Article de revue.
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Corrosion in Reverse Osmosis Desalination Processes : Forms and Mitigation Practices

Résumé : Membrane-based desalination is dominated by the reverse osmosis (RO) technology since the late 1990s. This technology is progressing very fast to replace most of the thermal-based desalination technologies. Since this process is dealing with ambient seawater with intensive pretreatment, corrosion and materials integrity in RO plants has many common practices with oil and gas industry, particularly in offshore installations. In the present chapter, crevice and microbial corrosion are described as the main corrosion forms in RO systems based on practical desalination experience. The corrosion-resistant alloys (CRAs) used in RO plants, and major research efforts and case studies in this area are discussed. Material selection criteria and future trends and opportunities are highlighted.
Domaine de référence : Biocorrosion
Auteur Meroufel Abdelkader A., Saji Viswanathan S., Meroufel Abdelkader A., Sorour Ahmad A.
Année de parution : 2020.
Mots-clés : Biofilm, Crevice corrosion, Pitting, Reverse osmosis, Stainless steel.
Type de document : Chapitre de livre.
Source : Springer International Publishing
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Bacterial distribution in SRB biofilm affects MIC pitting of carbon steel studied using FIB-SEM

Résumé : The bacterial distribution in biofilm and the longitudinal element distribution of MIC pitting by an SRB consortium were investigated using focused ion beam-scanning electron microscope (FIB-SEM). Results show that bacteria were surrounded by shells, and the bacterial distribution in the biofilm varied depending on the corrosion morphology. At the pitting corrosion area, cells gathered at the bottom of biofilm, while at the general corrosion area, cells distributed at the outer side of biofilm. The membrane potential measurement result shows that the biofilm has an anion selectivity. MIC pitting mechanism was proposed considering the bacterial distribution and the biofilm ion selectivity.
Domaine de référence : Biocorrosion
Auteur Li Yingchao, Feng Siqiao, Liu Huamin, Tian Xiankai, Xia Yeyin, Li Mu, Xu Kai, Yu Haobo, Liu Qiaoping, Chen Changfeng
Année de parution : 2020.
Mots-clés : Bacterial distribution, FIB-SEM, Ion selectivity, MIC pitting, SRB consortium.
Type de document : Article de revue.
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Distinct Profiles in Microbial Diversity on Carbon Steel and Different Welds in Simulated Marine Microcosm

Résumé : The main studies on the corrosion of metals induced by microorganisms are directed only to the surface of the metal, without considering the presence of welds between these surfaces. For this reason, we evaluated the difference of microbial community grown in carbon steel coupons, and two different types of welds, E7018 and Tungsten electrodes, exposed under simulated microcosm. After 30 days, they were recovered, the biofilms scraped and the microbial communities analyzed by 16S rRNA gene sequencing. The results showed that there was a differentiated distribution among the three samples collected. Proteobacteria phylum composed most of the species described in all samples. At the class level, Gammaproteobacteria was the most detected, followed by Alphaproteobacteria and Flavobacteriia. The most prevalent order was Alteromonadales, which was present in Weld2, followed by Rhodobacteriales, which was more prevalent in Fe1020 and Weld1. The orders Cytophagales, Sphingomonadales, and Burkholderiales were described in higher number in Fe1020, whereas Oceanospirillales, Thiotrichales, Flavobacteriales, Rhodospirillales, and Kordiimonadales were higher in samples Weld1 and Weld2. The analyses between the three evaluated conditions show the presences of bacterial groups preferred by different types of metal, suggesting that approaches in the control of biocorrosion should take into account the chemical composition of the metal.
Domaine de référence : Biocorrosion
Auteur Garcia Maurício, Procópio Luciano
Année de parution : 2020.
Type de document : Article de revue.
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Trained to corrode : Cultivation in the presence of Fe(III) increases the electrochemical activity of iron reducing bacteria - An in situ electrochemical XANES study

Résumé : This paper reports results from in situ electrochemical X-ray absorption near-edge spectroscopy (XANES) studies of the corrosion processes on model thin iron films in the presence of iron reducing bacteria Shewanella putrefaciens. Here we investigate the electrochemical activity of two cultures grown in the presence and absence of Fe(III) citrate in the culture medium. The XANES spectra and the OCP data of the Fe sample incubated with the culture grown in absence of Fe(III) did not show any significant changes during twenty hours of monitoring. In the case of the culture grown in Fe(III) containing medium, an accelerated dissolution of the iron film was observed together with the formation of a mixed Fe(II)-Fe(III) hydroxide surface layer. The open circuit potential (OCP) steadily approached the free corrosion potential of iron in neutral chloride containing electrolytes, indicating a continuous dissolution process without passivation.
Domaine de référence : Biocorrosion
Auteur Wurzler Nina, Schutter Jan David, Wagner Ralph, Dimper Matthias, Lützenkirchen-Hecht Dirk, Ozcan Ozlem
Année de parution : 2020.
Mots-clés : CN32, In situ electrochemical XANES, Iron reducing bacteria, MIC, Microbiologically influenced corrosion, XANES.
Type de document : Article de revue.
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The contribution of nitrate-reducing bacterium Marinobacter YB03 to biological souring and microbiologically influenced corrosion of carbon steel

Résumé : We have previously studied the effect of nitrate addition on the souring caused by sulfate-reducing bacteria (SRB). It revealed that the nitrate addition could suppress the growth of SRB and stimulate the growth of nitrate-reducing bacteria (NRB). It is not quite clear, however, whether NRB could lead to souring in oil fields and Microbiologically Influenced Corrosion (MIC). In this study, we isolated NRB and investigated the effect of isolated NRB on souring and MIC. Based on 16S ribosomal RNA identification, isolated NRB belongs to the genus Marinobacter and was named Marinobacter YB03. This bacterium is identified as NRB with sulfate reducing ability. Severe pitting corrosion was found on the carbon steel coupon associated with YB03. Therefore, YB03 promotes souring and corrosion.
Domaine de référence : Biocorrosion
Auteur Yuk Sokunsreiroat, Kamarisima, Azam Aa Haeruman, Miyanaga Kazuhiko, Tanji Yasunori
Année de parution : 2020.
Mots-clés : Microbiologically influenced corrosion, Pitting, Souring, Sulfate reduction.
Type de document : Article de revue.
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Microbiologically influenced corrosion of 304 stainless steel by nitrate reducing Bacillus cereus in simulated Beijing soil solution

Résumé : In this work, microbiologically influenced corrosion (MIC) of 304 stainless steel (SS) caused by Bacillus cereus was investigated by electrochemical measurements and surface analyses in simulated Beijing soil solution under aerobic condition. The nitrate-reducing bacterium (NRB), B. cereus, was isolated from Beijing soil and identified using 16S rDNA. Confocal laser scanning microscopy (CLSM) images showed that the largest pit depths on 304 SS with and without B. cereus after 14 days of incubation were 7.17 and 4.59 μm, respectively, indicating that pitting corrosion was accelerated by B. cereus. X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometry (EDS) results revealed that B. cereus and its metabolic products were detrimental to the integrity of the passive film on 304 SS. The electrochemical results showed that B. cereus significantly reduced the corrosion resistance of 304 SS and accelerated the anodic dissolution reaction, thereby speeding up the corrosion process.
Domaine de référence : Biocorrosion
Auteur Yu Si, Lou Yuntian, Zhang Dawei, Zhou Enze, Li Zhong, Du Cuiwei, Qian Hongchang, Xu Dake, Gu Tingyue
Année de parution : 2020.
Mots-clés : Microbiologically influenced corrosion, Nitrate-reducing bacterium, Soil corrosion, Stainless steel.
Type de document : Article de revue.
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Enzymes Participating in Extracellular Electron Transfer and Utilization of Same

Résumé : It has been considered that metal corrosion arises since hydrogen sulfide produced by sulfate-reducing bacteria takes electrons from iron and thus converts iron into iron sulfide. However, it is known that corrosion proceeds even after the surface of iron has been coated with iron sulfide and thus iron no longer comes into contact with hydrogen sulfide. The cause of this phenomenon had been unknown. The present inventors examined the electron uptake mechanism by precisely analyzing cellular membranes of sulfate-reducing bacteria, which proliferate using iron as an electron source, from the viewpoints of bioinformatics, biochemistry, electrochemistry and microscopic approach. As a result, the present inventors newly found enzymes having different structures from membrane enzymes which have been known as participating in electron withdrawal. The present inventors confirmed that electrons are drawn from electrodes exclusively when these enzymes are expressed in a large amount, and clarified for the first time that iron corrosion is caused by electron withdrawal directly from iron by bacteria due to the action of these enzymes, thereby completing the present invention.
Domaine de référence : Biocorrosion
Auteur Okamoto Akihiro, Deng Xiao
Année de parution : 0.
Type de document : Brevet.
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Corrosion Inhibitors in the Oil and Gas Industry

Résumé : Provides comprehensive coverage of corrosion inhibitors in the oil and gas industries Considering the high importance of corrosion inhibitor development for the oil and gas sectors, this book provides a thorough overview of the most recent advancements in this field. It systematically addresses corrosion inhibitors for various applications in the oil and gas value chain, as well as the fundamentals of corrosion inhibition and interference of inhibitors with co-additives. Corrosion Inhibitors in the Oil and Gas Industries is presented in three parts. The first part on Fundamentals and Approaches focuses on principles and processes in the oil and gas industry, the types of corrosion encountered and their control methods, environmental factors affecting inhibition, material selection strategies, and economic aspects of corrosion. The second part on Choice of Inhibitors examines corrosion inhibitors for acidizing processes, inhibitors for sweet and sour corrosion, inhibitors in refinery operations, high-temperature corrosion inhibitors, inhibitors for challenging corrosive environments, inhibitors for microbiologically influenced corrosion, polymeric inhibitors, vapor phase inhibitors, and smart controlled release inhibitor systems. The last part on Interaction with Co-additives looks at industrial co-additives and their interference with corrosion inhibitors such as antiscalants, hydrate inhibitors, and sulfide scavengers. -Presents a well-structured and systematic overview of the fundamentals and factors affecting corrosion -Acts as a handy reference tool for scientists and engineers working with corrosion inhibitors for the oil and gas industries -Collectively presents all the information available on the development and application of corrosion inhibitors for the oil and gas industries -Offers a unique and specific focus on the oil and gas industries Corrosion Inhibitors in the Oil and Gas Industries is an excellent resource for scientists in industry as well as in academia working in the field of corrosion protection for the oil and gas sectors, and will appeal to materials scientists, electrochemists, chemists, and chemical engineers.
Domaine de référence : Biocorrosion
Auteur Saji Viswanathan S., Umoren Saviour A.
Année de parution : 2020.
Mots-clés : Science / Chemistry / General, Technology & Engineering / Power Resources / Fossil Fuels.
Type de document : Livre.
Source : John Wiley & Sons
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Nutrient level determines biofilm characteristics and the subsequent impact on microbial corrosion and biocide effectiveness

Résumé : The impact that nutrient level has on biofilm characteristics, biocide effectiveness and the associated risk of microbiologically influenced corrosion (MIC) was assessed using multispecies biofilms from two different oilfield consortia. A range of microbiological, microscopy and corrosion methods demonstrated that the continuous flow of nutrients for the microbial growth resulted in higher activity, thickness and robustness of the biofilms formed on carbon steel, which induced greater localised corrosion compared to biofilms formed under batch, nutrient-depleted conditions. Despite of the differences in biofilms characteristics, biofilms displayed comparable susceptibility to glutaraldehyde biocide with similar log10 reduction and percent reduction of microorganisms in both nutrient conditions. Nevertheless, nutrient replenishment impacted the effectiveness of the biocide in controlling microbial populations; a higher concentration of cells survived the biocide treatment in biofilms formed under a continuous flow of nutrients. Complementary DNA and RNA-based amplicon sequencing and bioinformatics analysis were used to discriminate the active within the total populations in biofilms established at the different nutrient conditions and allowed the identification of the microbial species that remained active despite nutrient depletion and biocide treatment. Detection of persistent active microorganisms after exposure to glutaraldehyde, regardless of biofilm structure, suggested the presence of microorganisms less susceptible to this biocide and highlighted the importance of monitoring active microbial species for the early detection of biocide resistance in oil production facilities. Importance Microbiologically influenced corrosion (MIC) is a complex process that generates economic losses to the industry every year. Corrosion must be managed to prevent a loss of containment of produced fluids to the external environment. MIC Management includes the identification of assets with higher MIC risk, which could be influenced by nutrient levels in the system. Assessing biofilms under different nutrient conditions is essential for understanding the impact of flow regime on microbial communities and the subsequent impact on microbial corrosion and on the effectiveness of biocide treatment. This investigation simulates closely oil production systems, which contain piping sections exposed to continuous flow and sections that remain stagnant for long periods. Therefore, results reported here are useful for MIC management and prevention. Moreover, the complementary methodological approach applied in this investigation highlighted the importance of implementing RNA-based methods for better identification of active microorganisms that survive stress conditions in oil systems.
Domaine de référence : Biocorrosion
Auteur Salgar-Chaparro Silvia J., Lepkova Katerina, Pojtanabuntoeng Thunyaluk, Darwin Adam, Machuca Laura L.
Année de parution : 2020.
Type de document : Article de revue.
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Corrosion Defect Modelling of Aged Pipelines with a Feed-Forward Multi-Layer Neural Network for Leak and Burst Failure Estimation

Résumé : Determination of the future Corrosion Defect Depth (CDD) growth of the oil and gas pipelines is vital for the management of the integrity and mitigation of failures that can affect health, safety, and the environment. To this end, this work uses the historical operating parameters for establishing the time-dependent CDD growth of corroded pipelines based on machine learning. This data-driven machine learning relies on feed-forward Subspace Clustered Neural Network (SSCN) and Particle Swarm Optimization (PSO) to estimate the CDDs of a single-SSCN by treating the first Subspace Cluster (SSC) as a regression model that comprises of the hidden and bias layers and the input variables. The multi-SSCN model is linked to the single-SSCN model through individual values decoupling, transformations and modifications of the hyperspace of the deeper layers in the SSCN model. The CDDs estimated with the SSCN models are used for a Weibull distribution dependent leak and burst failure probability estimation to compute the integrity of the pipelines at discrete sections. The results obtained demonstrate the potentials of this technique for the integrity management of corroded aged pipelines.
Domaine de référence : Biocorrosion
Auteur Ossai Chinedu I.
Année de parution : 2020.
Mots-clés : Burst and leak failure, corrosion defect-depth, feed-forward neural network, particle swarm optimization, pipeline integrity.
Type de document : Article de revue.
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Sulphate Reducing Bacteria and Methanogenic Archaea Driving Corrosion of Steel in Deep Anoxic Ground Water

Résumé : During the operation, maintenance and decommissioning of nuclear power plant radioactive contaminated waste is produced. This waste is stored in an underground repository 60-100 meters below the surface. The metallic portion of this waste comprises mostly carbon and stainless steel. A long-term field exposure showed high corrosion rates, general corrosion up to 29 μm a-1 and localized corrosion even higher. High corrosion rate is possible if microbes produce corrosive products, or alter the local microenvironment to favor corrosion. The bacterial and archaeal composition of biofilm formed on the surface of carbon steel was studied using 16S rRNA gene targeting sequencing, followed by phylogenetic analyses of the microbial community. The functional potential of the microbial communities in biofilm was studied by functional gene targeting quantitative PCR. The corrosion rate was calculated from weight loss measurements and the deposits on the surfaces were analyzed with SEM/EDS and XRD. Our results demonstrate that microbial diversity on the surface of carbon steel and their functionality is vast. Our results suggest that in these nutrient poor conditions the role of methanogenic archaea in corrosive biofilm, in addition to sulphate reducing bacteria, could be greater than previously suspected.
Domaine de référence : Biocorrosion
Auteur Rajala P., Raulio M., Carpén L.
Année de parution : 2019.
Type de document : Article de revue.
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Electrochemical Study of the Biocorrosion of Aluminum Alloy 7075

Résumé : A bacterial consortium collected from the fuel line of a military aircraft was investigated to evaluate the corrosion behavior of the aluminum alloy 7075 in sterile minimal salt medium (MSM). The isolation and characterization of the consortia by DNA sequencing showed that the consortium was mainly composed of seven bacteria. Electrochemical results revealed that the corrosion rate was not influenced in sterile and inoculated media. In particular, a corrosive behavior was determined in presence of a bacterium, which has a close affiliation to Pseudomonas Stuzeri strain. SEM examinations and EDX analysis of metallic samples exposure in inoculated media revealed local corrosion.
Domaine de référence : Biocorrosion
Auteur Vejar Nelson D, Alvarado Claudia, Aguilar Claudio, Sacre Juan, Pineda Fabiola, Sancy Mamie
Année de parution : 2016.
Type de document : Article de revue.
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Effect of Phenols on Biological Zinc Corrosion

Résumé : It has been shown that treating a zinc surface with phenols (phenol, 2,6-di-tert-butyl-4-methylphenol (ionol), hydroquinone, pyrocatechol, 3,5-di-tert-butyl-pyrocatechol) increased the corrosive damage of the metal caused by microorganisms. It has been suggested that corrosion stimulation was caused by radical processes involving phenols adsorbed on the metal surface and products of oxygen biotransformation by microorganisms.
Domaine de référence : Biocorrosion
Auteur Kalinina A. A., Temnova M. V., Sokolova T. N., Kuzina O. V., Razov E. N., Kartashov V. R.
Année de parution : 2020.
Mots-clés : activation of biocorrosion, biological corrosion, micromycetes, organotrophic bacteria, phenols, reactive oxygen species, zinc.
Type de document : Article de revue.
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Application of Essential Oils as Green Corrosion Inhibitors

Résumé : This review reports the application of essential oils (EOs) as a green corrosion/biocorrosion inhibitor. The topics discussed are: (i) sources and composition of EOs, (ii) adsorption mechanism, (iii) anticorrosion effects of EOs on metal surfaces, (iv) electrochemical investigations, (v) antimicrobial activity of EOs on corrosion-producing bacteria and algae, (vi) synergetic effects of EOs, and (vii) economical aspect and application of inhibitors. Various aspects of biofilms are discussed to identify microbiologically influenced corrosion (MIC) and the characterization of microorganisms causing MIC. The studies indicate that EOs have the potential as eco-friendly corrosion inhibitors in both aggressive chemicals and biofilm environments.
Domaine de référence : Biocorrosion
Auteur Hossain S. M. Z., Razzak S. A., Hossain M. M.
Année de parution : 2020.
Mots-clés : Corrosion, Essential oil, Metabolomics, Microbiologically influenced corrosion, Solid-phase microextraction.
Type de document : Article de revue.
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Influence of Phase Composition of Steel on a Damage Rate from Bio-Corrosion

Résumé : The complex research of influence of a structural condition of metal on resistance to corrosion destruction of the low-alloyed steel, operated in biocorrosion environments, is conducted. It is established that the ferritic component of a structure resists better in the environment modeling conditions of impact of biogenous gases on metal under the exfoliated anticorrosive covering. Ferrite – carbide mix, in the form of beynit, has a bigger resistance in the environment reproducing conditions of lack of biogenous factors. Existence in beynitny structure of a martensitic component leads to the largest resistance of biocorrosion in the environment modeling conditions of anaerobic corrosion with biogenous gases.
Domaine de référence : Biocorrosion
Auteur Volgina Natalya I., Saltykova Tatyana S., Hlamkova Svetlana S.
Année de parution : 2020.
Type de document : Page Web.
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Review on the microbiologically influenced corrosion and the function of biofilms

Résumé : The microbiologically/microbially influenced corrosion (MIC) is a special type of corrosion; in this case the microorganisms by their presence and aggressive metabolites alter the processes on solid surfaces via electrochemical and chemical reactions. When microorganisms are present in most cases the degradation of metals or alloys happens by microbes embedded in biofilms and by their excreted metabolites (e.g. acids), macromolecules (with complexing ability) and by other molecules that can form insoluble precipitates; all these reactions increase the deterioration. The paper summarizes the most important characteristics of the MIC, mainly the so-called biocorrosion of metals and alloys. Not only the chemical and electrochemical processes, but the roles of the corrosion relevant microorganisms in the deteriorating processes, as well as the information about the mechanisms of the MIC worked out in the past and in the very last period are discussed. The most important (aerobic, anaerobic, slime former, acid producer etc.) microorganisms, their nutrient requirements and the formation and role of biofilms are presented, characterized and discussed, as well as the influence of biofilms on the MIC is also demonstrated. The impact of metals on the MIC is also discussed. The history of the research on MIC from its discovery till the 21th century will demonstrate the enormous work that allowed the understanding of this special type of corrosion as well as its mechanism and the role of the biofilm in MIC. The paper will expose the reactions that go on between the slimy layer (that surrounds the microorganisms even in planktonic form) and the metal surface. The mostly used techniques to visualize what on the surface happens and to measure the change in the current density/corrosion potential and in the corrosion rate due to microbial action are also summarized and in all cases the advantages and disadvantages of all methods are discussed.
Domaine de référence : Biocorrosion
Auteur Telegdi J, Shaban A, Trif L
Année de parution : 2020.
Type de document : Article de revue.
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Corrosion behavior and interaction of mixed bacteria on carbon steel in reclaimed water

Résumé : At present, the researches on the corrosion of mixed microorganisms pay more attention to iron-oxidizing bacteria (IOB) and sulfate-reducing bacteria (SRB) in tap water or seawater. Pseudomonas fluorescens and Escherichia coli are two common microorganisms in reclaimed water, but there are few studies about their interaction on metal interface and about their influence on metal corrosion behavior. The corrosion behavior of carbon steel under mixed microorganisms of Escherichia coli and Pseudomonas fluorescens was studied by corrosion weight loss, electrochemistry, scanning electron microscopy (SEM) and X-ray diffraction (XRD) in this paper. The dominant bacteria under mixed bacteria conditions determined the final result of corrosion reaction in reclaimed water. On the first three days, the dominant strain was Escherichia coli, which produced acid on the surface of carbon steel and deteriorated corrosion. After the 3rd day, the dominant strain was Pseudomonas fluorescens, which inhibited the growth of Escherichia coli and slowed down corrosion. When the extracellular polymeric substances (EPS) concentration of Pseudomonas fluorescens reached 400 mg/L, it would inhibit the growth and reproduction of Escherichia coli. On the contrary, Escherichia coli EPS acted as a nutrient for Pseudomonas fluorescens, promoting the growth and reproduction of Pseudomonas fluorescens.
Domaine de référence : Biocorrosion
Auteur Chu Yajun, Xu Ping, Ou Yumin, Bai Pengkai, Wei Zhigang
Année de parution : 2020.
Mots-clés : Carbon steel, Corrosion behavior, Interaction.
Type de document : Article de revue.
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The effect of magnetic field pretreatment on the corrosion behavior of carbon steel in static seawater

Résumé : The corrosion behavior of carbon steel pretreated with a magnetic field before electrochemical testing was investigated in static seawater using electrochemical methods in the absence of an external magnetic field. The shift in corrosion potential was more significant with increasing pretreating magnetic field strength, and the corrosion current density also decreased. This implies that the carbon steel corrosion was inhibited. The main reason for this inhibition is that the magnetic field affects the formation of intermediate products on the carbon steel surface by both charge transfer and magnetic ion adsorption. The magnetic field pretreatment will likely offer a new approach for marine anti-corrosion technology
Domaine de référence : Biocorrosion
Auteur Zhao Shuanzhu, Wang Yaxin, Zhao Yunxiu, Sun Xiaotong, Zhang Huijuan, Piao Hong-Guang, Zhang Yujiao, Huang Yanliang
Année de parution : 2019.
Type de document : Article de revue.
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Microbiologically influenced corrosion of 304 stainless steel by halophilic archaea Natronorubrum tibetense

Résumé : The corrosion behavior of 304 stainless steel (SS) in the presence of aerobic halophilic archaea Natronorubrum tibetense was investigated. After 14 days of immersion, no obvious pitting pit was observed on the SS surface in the sterile medium. By contrast, the SS exhibited serious pitting corrosion with the largest pit depth of 5.0 μm in the inoculated medium after 14 days. The results of electrochemical tests showed that the barrier property of the passive film decreased faster in the inoculated medium. The X-ray photoelectron spectroscopy results indicated that the detrimental Fe2+ and Cr6+ increased in the passive film under the influence of archaea N. tibetense, which resulted in the accelerated deterioration of passive film and promoted the pitting corrosion. Combined with the energy starvation tests, the microbiologically influenced corrosion mechanism of 304 SS caused by halophilic archaea N. tibetense was discussed finally.
Domaine de référence : Biocorrosion
Auteur Qian Hongchang, Ma Lingwei, Zhang Dawei, Li Ziyu, Huang Luyao, Lou Yuntian, Du Cuiwei
Année de parution : 2020.
Mots-clés : Archaea, Microbiological influenced corrosion, Stainless, steel.
Type de document : Article de revue.
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Long term effect of strength and durability performance of concrete containing sulphate reduction bacteria under chloride condition

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


• Antifouling icone-flux-rss

Properties of Iron Bacteria Biofouling on Ni-P-rGO Coating under Flowing Conditions

Résumé : Biofouling on heat exchange devices can decrease heat transfer efficiency, corrode materials, and even lead safety accidents. Most heat exchange devices are made of carbon steel, which produces biofouling easily. In this paper, nickel-phosphorus-reduced graphene oxide (Ni-P-rGO) coating was prepared on carbon steel by electroless plating as a kind of advanced material to study the properties of iron bacteria biofouling under flowing conditions. The coating was analyzed via scanning electron microscopy and Raman spectroscopy. The properties of iron bacteria biofouling on carbon steel and Ni-P-rGO coating were then compared under flowing conditions. Compared with carbon steel, the asymptotic value of fouling resistance on the Ni-P-rGO coating significantly decreased. Additionally, the induction period and the time of reaching the asymptotic value greatly increased. The inhibition properties of biofouling of advanced materials Ni-P-rGO coating under different temperatures, flow velocities, and initial concentrations was also studied.
Domaine de référence : Antifouling
Auteur Sun Mingyang, Xu Zhiming, Liu Zuodong, Wang Bingbing, Di Huishuang
Année de parution : 2020.
Mots-clés : biofouling, fouling resistance., induction period, iron bacteria, nickel-phosphorus-reduced graphene oxide (Ni-P-rGO).
Type de document : Article de revue.
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Ocean acidification affects microbial community and invertebrate settlement on biofilms

Résumé : Increased atmospheric CO2 is driving ocean acidification (OA), and potential changes in marine ecosystems. Research shows that both planktonic and benthic communities are affected, but how these changes are linked remains unresolved. Here we show experimentally that decreasing seawater pH (from pH 8.1 to 7.8 and 7.4) leads to reduced biofilm formation and lower primary producer biomass within biofilms. These changes occurred concurrently with a re-arrangement of the biofilm microbial communities. Changes suggest a potential shift from autotrophic to heterotrophic dominated biofilms in response to reduced pH. In a complimentary experiment, biofilms reared under reduced pH resulted in altered larval settlement for a model species (Galeolaria hystrix). These findings show that there is a potential cascade of impacts arising from OA effects on biofilms that may drive important community shifts through altered settlement patterns of benthic species.
Domaine de référence : Antifouling
Auteur Nelson Katie S., Baltar Federico, Lamare Miles D., Morales Sergio E.
Année de parution : 2020.
Type de document : Article de revue.
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Practical Applications of Superhydrophobic Materials and Coatings : Problems and Perspectives

Résumé : Synthetic superhydrophobic (SH) surfaces were developed after 1990s and the number of publications in this field is around 13.500 at present. However, the industrial production of the SH coatings is very unsatisfying after the intensive research activity especially in the last two decades. The main reason is the loss of the water repellence properties when SH surfaces are exposed to outdoor conditions due to their weak mechanical properties and contamination from the medium which remove the initial SH properties. In this Feature Article, we focus on the scientific and technical reasons which prevent the application of the SH surfaces in our daily lives by highlighting some well-known, but mostly overlooked problems in this area (the synthesis methods of SH surfaces is not the subject of this article since they were reviewed previously in very good articles). The basic contact angle science and the issue of the cancellation of the Wenzel and Cassie & Baxter equations are reviewed in the first part. The issues of the expensive and small scale SH surface preparation problems, the difficulties to obtain a transparent SH surface, the troubles arising from the water vapor condensation on a SH surface, the lack of robustness and abrasion resistance of most of the SH surfaces, the drawbacks of the fabricated self-healing SH surfaces, the short useful service life of self-cleaning SH surfaces due to the surface contamination and the ineffective anti-icing SH coatings are reviewed in the following parts. Some important problems affecting the unsuccessful industrial applications of the SH surfaces are discussed critically in the conclusions and outlook section. Finally, some proposals are presented for the future directions on the synthesis and application of SH surfaces.
Domaine de référence : Antifouling
Auteur Erbil H. Yildirim
Année de parution : 2020.
Type de document : Article de revue.
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Effects of exogenous quorum quenching on microbial community dynamics and biofouling propensity of activated sludge in MBRs

Résumé : Recently, bacterial quorum quenching (QQ) has been proven as a novel approach for biofouling mitigation in membrane bioreactors (MBRs). The information about microbial community is vital for the development of QQ strategies. Also, the change of microbial community may affect the biofouling propensity of sludge. In this study, the effects of exogenous QQ on microbial community dynamics in MBRs were investigated, along with biofouling propensity of activated sludge. QQ MBR dosed with exogenous QQ bacteria exhibited a better anti-biofouling, whereas the wastewater treatment performance was almost no difference compared with control MBR. As for the microbial community, exogenous QQ had an impact on both the bacterial diversities and community composition, especially for the quorum sensing (QS) and QQ bacteria in situ. The addition of exogenous QQ could reduce the QQ ability of sludge itself in the short term, and enhance its biofouling propensity. These findings provided new insights for the development of QQ strategies.
Domaine de référence : Antifouling
Auteur Ouyang Yichen, Hu Yi, Huang Jinhui, Gu Yanling, Shi Yahui, Yi Kaixin, Yang Ying
Année de parution : 2020.
Mots-clés : Biofouling, Exogenous quorum quenching, Membrane bioreactor, Microbial community, Quorum sensing.
Type de document : Article de revue.
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Environmentally friendly marine antifouling coating based on a synergistic strategy

Résumé : Development of environmentally friendly and long-term marine antifouling coating remains a huge challenge in maritime industry. For this purpose, we developed a novel and efficient antifouling coating based on a synergistic strategy, incorporating contact inhibition, fouling-repelling and antifouling. Results demonstrated the coating could efficiently resist the adhesion of protein, bacteria, and Navicula diatoms. More importantly, marine field tests showed the coating could efficiently inhibit biofouling for at least 8 months. This approach paves a new way for the development of environmentally friendly and long-term antifouling coating.
Domaine de référence : Antifouling
Auteur Xie Changhai, Guo Hongshuang, Zhao Weiqiang, Zhang Lei
Année de parution : 2020.
Type de document : Article de revue.
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Impact of biofilm on the ship propulsion characteristics and the speed reduction

Résumé : Ship fuel consumption and the greenhouse gas emissions in the service are affected by various factors, including waves, wind, biofouling, corrosion, confined water. One of the operational measures for the reduction of the fuel consumption is the optimization of the maintenance schedule, but lack of information related to the potential benefits of the application of this measure represents an important barrier. Therefore, the prediction of the impact of biofouling on ship hydrodynamic characteristics is important. In this paper, a numerical model based on Reynolds Averaged Navier-Stokes (RANS) equations, which allows the prediction of the impact of biofilm on the ship propulsion characteristics is proposed. Roughness function models representing surface conditions of biofilm fouling were employed within the wall function of the CFD software. Thereafter, a detail analysis of the impact of biofilm on the propulsion characteristics and the flow around full-scale containership is presented. This study has demonstrated that the occurrence of biofilm should not be ignored and that the presence of biofilm can cause extremely detrimental effects on ship hydrodynamic characteristics. Thus, it is shown that the biofilm can cause a significant increase in delivered power and consequently an increase in fuel consumption or a decrease in ship speed, contradicting the often ignoring of the biofilm presence on the ship hull.
Domaine de référence : Antifouling
Auteur Farkas Andrea, Song Soonseok, Degiuli Nastia, Martić Ivana, Demirel Yigit Kemal
Année de parution : 2020.
Mots-clés : Biofilm, Biofouling, CFD, Container ship, Propulsion characteristics, Roughness effect, Speed reduction.
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 : 2020.
Mots-clés : biocide, mcs, microcapsule, microcapsules, shell.
Type de document : Brevet.
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Introduction of an antifouling photoelectrode : an effective strategy for a high-performance photoelectrochemical cytosensor

Résumé : As nonspecific adsorption or biofouling has obvious side effects on the selectivity, it is a great challenge for cytosensors to detect target cells in practical biological samples. In this study, we first propose the design and synthesis of an antifouling photoelectrode. The antifouling photoelectrode not only has the desired photocurrent response, but also possesses an unexpected antifouling capability of resisting nonspecific adsorption of biomolecules. Herein, the PEDOT-HPG/SnS/ZnO-NT antifouling photoelectrode was formed and a robust photoelectrochemical cytosensor with enhanced sensitivity and selectivity has been demonstrated.
Domaine de référence : Antifouling
Auteur Ma Linzheng, Zhao Huan, Fan Gao-Chao, Luo Xiliang, Zhu Jun-Jie
Année de parution : 2020.
Type de document : Article de revue.
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Technologies for Biofouling Control and Monitoring in Desalination

Résumé : In seawater desalination plants, a wide variety of marine biofouling organisms enter the intake and distribution system and settled and grow as it provides optimal conditions for the buildup of biofouling communities. This settlement results in an increased wall roughness of the material and reduces the pipe diameter resulting in the hydraulic head loss. To prevent biofouling settlement, generally, biocides are dosed at the seawater intake. Chlorination has shown to be a proven practice in the past decades to be efficient in avoiding biofouling in seawater intakes and culverts. However, the dosing strategy is often “standard” and not tailored to local requirements or potential adverse side effects. This chapter provides a detailed account of the fundamentals of biofouling and their impacts on seawater desalination. Both physical and chemical methods of biofouling control that are currently in use in industrial desalination plants are explained. An account of biofouling monitoring is also provided.
Domaine de référence : Antifouling
Auteur Polman H. J. G., Jenner H. A., Bruijs M. C. M., Saji Viswanathan S., Meroufel Abdelkader A., Sorour Ahmad A.
Année de parution : 2020.
Mots-clés : Biocides, Biofilm, Biofouling, Headloss, Seawater intake.
Type de document : Chapitre de livre.
Source : Springer International Publishing
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Environmentally Benign Marine Antifouling Coatings

Résumé : The formation of biofilms of marine organisms on the surfaces of ship hulls, rudders, and propellers, heat exchangers in cooling water systems, water treatment membranes, aquatic sensors, and other equipment in contact with the marine environment is a challenging problem, associated with not only increased operation and maintenance costs, but also damage and loss of functionality caused by microbially induced corrosion. Surface modification using coatings is an approach that has been widely used to control marine biofilm formation. Until recently, marine antifouling coatings incorporated biocides that killed the microorganisms, and consequently had an unfavorable effect on the marine ecosystem. Over the past two decades, however, several environmentally friendly nanostructured polymer coatings have been developed as promising alternatives to the biocidal paints. Beginning with a brief discussion of the environmental problems arising from the use of biocides, this chapter examines the macromolecular structural design and surface science strategies used in the development of environmentally friendly nontoxic coatings. Fouling release coatings of block copolymers with fluorinated liquid crystalline side chains, silicone coatings filled with nanoparticles, hydrophilic antifouling coatings, amphiphilic block copolymer coatings, and coatings with nanoscale surface heterogeneities are discussed, along with a detailed specification of their surface properties, probed using techniques such as surface wettability analysis, near‐edge X‐ray absorption spectroscopy, and atomic force microscopy. Some biomimetic approaches, such as the incorporation of microorganisms that produce fouling‐deterrent secondary metabolites, are also highlighted.
Domaine de référence : Antifouling
Auteur Sitaraman Krishnan
Année de parution : 2019.
Mots-clés : 100205 Environmental Marine Biotechnology, 30603 Colloid and Surface Chemistry, 90301 Biomaterials.
Type de document : Article de revue.
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Attachment of Marine Microorganisms to Surfaces

Résumé : The attachment mechanisms of the main groups of marine microorganisms are similar. These similarities are particularly shown by the nature of the adhesive mucilages they produce. Marine bacteria, cyanobacteria and diatoms produce acidic polysaccharide mucilages. Macroalgal spores attach by the production of glycoprotein adhesives. The spores of several marine Ascomycete fungi attach by means of mucilaginous, fibrillar appendages, although little is known about their composition. Certain marine bacteria possess cell-surface structures such as stalks with holdfasts, flagella and spinae which may play an attachment role. Cyanobacteria possess pili and spinae which may serve the same purpose. The formation of proteinaceous conditioning films on substrata promotes bacterial adhesion. Polymeric polysaccharide materials and bacterial films also precondition surfaces for algal attachment. Substratum properties such as wettability and surface free energy can affect, and in some cases decrease, levels of bacterial and algal attachment. Marine microbial adhesion is of importance in disease pathogenesis, biotic interactions, physical interactions and certain economic aspects. In disease pathogenesis, the attachment of Aeromonas salmonicida to fish cells by the 'A'-protein layer is important in the initiation of furunculosis. Some invertebrate diseases are also caused by attached microorganisms. The bacterium Leucothrix mucor, along with diatoms, cyanobacteria and protozoa can accumulate on the gills of shrimps, crabs and lobsters. This heavy infestation causes death by suffocation. Vibrio cholerae attaches to the oral region of planktonic copepods and the hindgut of the blue crab Callinectes sapidus. These observations may be important for the epidemiology of cholera in aqueous environments. Microbial attachment may also be important in the establishment of symbiotic relationships with certain marine invertebrates. Biotic interactions include the formation of primary microbial films on any new surface immersed in seawater. Extensive microbial epiphytic layers form on seaweeds and estuarine salt marsh grasses. Bacteria which attach to the heterocysts of the cyanobacterium Anabaena spp. in the freshwater environment could be involved in nitrogen fixation. The parasitic marine bacterium Bdellovibrio bacteriovorus attaches to host cell membranes by cell-surface fibres, which ultimately leads to cell lysis. Attached bacteria are responsible for the aggregation of particulate detritus, which eventually disaggregates due to protozoal activity. Bacteria utilize dissolved organic carbon for the formation of adhesive materials which cause detrital aggregation. The attachment of bacteria to certain phytoplankton, including diatoms, ultimately results in the formation of amorphous detrital aggregates. Physical interactions include microbial attachment to sediments. Microbial attachment and adhesive production is important in the formation of microbial mats. Marine bacteria, cyanobacteria and diatoms are abundant in these mats. Microbial extracellular polymer material is responsible for lamination of mat layers and the structural integrity of the mats. Gelatinous mats are often formed in sediments from microalgal adhesive secretions. These mats are of importance in sediment stabilization. The adhesive mucilages of certain diatoms also reduce the resuspension of sediment particles. Microbial extracellular materials may also be utilized as a food source by benthic invertebrates. One economic aspect of marine microfouling is metal corrosion. Corrosion can result from the formation of differential aeration cells under a non-uniform film of attached microorganisms. Sulphate-reducing bacteria, which are often present in biofilms under anaerobic conditions corrode metals by cathodic depolarization. This process allows the formation of corrosive hydrogen sulphide and iron sulphide from sulphates. Some diatoms, such as Amphora spp., may inhibit corrosion by forming a uniform layer of adhesive mucilage over a metal surface. A further economic aspect is the affect of microbial attachment on the development of antifouling techniques. Bacterial and diatom slime films are easily formed on cuprous oxide and organometallic antifouling paints. This makes them less effective. The effects of surface free energy and wettability of substrata on bacterial and algal adhesion could provide a further antifouling technique. Conditioning film formation can alter these substratum properties towards a biocompatible range where lower rates of microfouling occur. The incorporation of silicone elastomers in substrata also decreases bacterial and diatom attachment. The use of metabolic inhibitors or calcium chelating agents to remove bacterial and diatom films could be a further antifouling development.
Domaine de référence : Antifouling
Auteur Boney Andrew James Victor
Année de parution : 1991.
Type de document : Thèse.
Source : ProQuest Dissertations & Theses,
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Silicone-Based Fouling-Release Coatings for Marine Antifouling

Résumé : Marine biofouling profoundly influences marine industries and activities. It slows the speed and increases the fuel consumption of ships, corrodes the offshore platforms and blocks the seawater pipelines. The most effective and economic antifouling approach is using coatings. Fouling release coatings (FRCs) with low surface free energy and high elasticity weakly adhere to marine organisms so they can be readily removed by the water shear force. FRCs have received increasing interest because they are biocide-free and hence eco-friendly. Yet, traditional silicone based FRCs have weak adhesion to substrate, low mechanical strength and low fouling resistance, limiting their applications. In recent years, many attempts have been made to improve their mechanical properties and fouling resistance. The review deals with the progress in construction of high-performance silicone based fouling release surfaces.
Domaine de référence : Antifouling
Auteur Hu Peng, Xie Qingyi, Ma Chunfeng, Zhang Guangzhao
Année de parution : 2020.
Type de document : Article de revue.
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PhD Studentship - Control of Biofouling in Water Pipes Using Guided Waves at University of Southampton

Résumé : A major issue for the water industry in a number of countries, including the UK, is the attachment of large populations of mussels to the inside of pipe walls causing significant flow resistance. A novel and chemical-free solution to this problem might be to vibrate the pipe wall, either to overcome their adhesion to the surface or to discourage their attachment in the first place. The aim of this project is to explore the feasibility of disturbing mussels in an environmentally friendly manner by injecting ‘guided waves’ into the pipe wall. In particular, the wave energy will be focused at movable target positions to compensate for attenuation along the pipe due to energy losses which would otherwise limit an actuator’s range. The project will involve modelling of wave propagation in fluid-filled pipes using semi-analytical and numerical techniques, and both laboratory and field measurements. You will join the Institute of Sound and Vibration Research at the University of Southampton, a vibrant research community with an international reputation for innovative and impactful research spanning over 50 years. You will have a first or upper second class Bachelors’ or Masters’ degree in a mechanically based engineering subject, or in physical sciences. You will have a proven track record in computer modelling. Programming in any language is desirable. Prior knowledge of mechanical vibrations is advantageous, although taught modules will be available for those with some or no previous background.
Domaine de référence : Antifouling
Année de parution : 2020.
Type de document : Page Web.
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Chemistry and application of emerging ecofriendly antifouling paints : a review

Résumé : There has been a global concern about the use of tributyltin-based coatings in combating biofouling in the marine industry. Although there have been alternatives to tributyltin in preventing biofouling, the emphasis is now on the use of nontoxic and/or ecofriendly natural materials which do not negatively affect the environment upon application. Natural materials are ecofriendly, biodegradable, cost-effective, and can be employed as precursors in the synthesis and formulation of biodegradable antifouling coatings. Consequently, many researchers are investing time into the synthesis and formulation of natural, ecofriendly antifouling coatings, comprised of higher biofiber, which would perform analogous antifouling like other conventional coatings, thus minimizing the more toxic base polymer proportion. A safe environment is surely the signal of a bright future; hence, cost-effective, biodegradable raw materials result in a long-term attainment of sustainability of these products to replace the expensive conventional ones. This review presents an overview of ecologically friendly, cost-effective, and legally acceptable ways of preventing and mitigating the growth of algae and other marine organisms from settling on the hull of a ship and other static constructions in oilfields.
Domaine de référence : Antifouling
Auteur Kyei Sampson Kofi, Darko Godfred, Akaranta Onyewuchi
Année de parution : 2020.
Mots-clés : Biodegradable, Biofouling, Coatings, Ecofriendly, Natural materials, Sustainability.
Type de document : Article de revue.
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Strategies for Material Protection in Aquatic Environment

Résumé : Settlement of micro and macro and microorganisms over the submerged materials is called biofouling. If a material is immersed in aquatic environment it will experience an initial formation of biofilm. This is due to the adsorption of proteins, polysaccharides, macro and micro organic molecules over the surface. This complex nutrient rich surface attracts bacteria, fungi, diatoms and micro algae, and this layer is called biofilm [Avelelas et al 2017]. Organisms like barnacles, mussels, sponges, polychaetes, oysters etc attach over the biofilm and this results in degradation of materials or change the physico-chemical characteristics.
Domaine de référence : Antifouling
Auteur Ashraf P Muhamed
Année de parution : 2019.
Type de document : Article de revue.
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Mitigate marine macrofoul growth on underwater surface using the generated wall shear stress from confined radial outflow

Résumé : Ocean vessels experience heavy biofouling pressure when stationary for extended periods of time. Deploying a vessel without cleaning the hull results in a significant reduction in operational efficiency. A neutrally buoyant and contactless grooming device utilizes confined radial outflow at a constant flow rate to detach organisms using peak wall shear in addition to securely levitating parallel to the hull at some equilibrium gap height, where the overall force generated by the fluid field is zero. Changing the buoyancy to either increase the gap height will cause a suction force to pull the pad towards the surface or decrease the gap height to push the pad away from the surface in the attempt to maintain equilibrium. 3D Particle Tracking Velocimetry (PTV) with four ultra high speed cameras captured the complex fluid flow in the gap, with the wall shear stress derived from the velocity vectors of 100,000 images at 20 kHz. Using the same device geometry and size, a field test study was conducted with image analysis to determine the effectiveness of various grooming frequencies (3x, 2x, 1x, 0.5x a week) on two different surfaces (untreated and antifouling treated fiberglass reinforced resin) for a duration of seven weeks. Funded by the Office of Naval Research.
Domaine de référence : Antifouling
Auteur Kamensky Kristina, Hellum Aren, Mejia-Alvarez Ricardo, Mukherjee Ranjan
Année de parution : 2019.
Type de document : Article de revue.
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Bioinspired PDMS–Phosphor–Silicone Rubber Sandwich-Structure Coatings for Combating Biofouling

Résumé : Inspired by the antifouling strategies of fluorescent corals and Gulf parrotfish, a novel polydimethylsiloxane (PDMS)–phosphor–silicone rubber sandwich-structure coating is fabricated for combating biofouling. The coatings can emit weak light during night hours and have hydrophilic surfaces. The effectiveness of the coatings against various algae and bacteria, namely, Chlorella, Nitzschia closterium f. minutissima, gram-negative Paracoccus pantotrophus, and gram-positive Bacillus subtili is investigated. The results show that the PDMS–phosphor–silicone rubber sandwich-structure coatings have broad-spectrum antifouling performances. The results also demonstrate that surface hydrophilicity can effectively reduce adhesion of algae and bacteria, and that fluorescence inhibits only algae. In addition, the effect is revealed of the wavelength of different colored phosphor layers on antifouling capability to resist Chlorella and N. closterium f. minutissima. Blue (427 nm), yellow (663 nm), and red (731 nm) phosphor layers are conducive to combating Chlorella and N. closterium f. minutissima, whereas the green (512 nm) phosphor layer shows no distinct effect on resisting Chlorella and N. closterium f. minutissima. These findings can contribute to the development of new antifouling coatings. In addition, the antifouling capabilities of these coatings have potential for further improvement and development. The sandwich-structure materials fabricated in this study should prove very useful in practical applications.
Domaine de référence : Antifouling
Auteur Jin Huichao, Bing Wei, Jin E., Tian Limei, Jiang Yonggang
Année de parution : 2020.
Mots-clés : antifouling coatings, bioinspired coatings, hydrophilic surfaces, layered materials.
Type de document : Article de revue.
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Love at First Taste : Induction of Larval Settlement by Marine Microbes

Résumé : Marine biofilms are composed of many species of bacteria, unicellular algae, and protozoa. Biofilms can induce, inhibit, or have no effect on settlement of larvae and spores of algae. In this review, we focus on induction of larval settlement by marine bacteria and unicellular eukaryotes and review publications from 2010 to September 2019. This review provides insights from meta-analysis on what is known about the effect of marine biofilms on larval settlement. Of great interest is the impact of different components of marine biofilms, such as bacteria and diatoms, extracellular polymeric substances, quorum sensing signals, unique inductive compounds, exoenzymes, and structural protein degradation products on larval settlement and metamorphosis. Molecular aspects of larval settlement and impact of climate change are reviewed and, finally, potential areas of future investigations are provided.
Domaine de référence : Antifouling
Auteur Dobretsov Sergey, Rittschof Daniel
Année de parution : 2020.
Mots-clés : bacteria, biofilm, diatoms, larval settlement, protozoa, settlement pheromones.
Type de document : Article de revue.
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Chitin is a functional component of the larval adhesive of barnacles

Résumé : Nick Aldred et al. show that chitin provides stability in the cyprid adhesive of the barnacle Balanus amphitrite. They show that a single cement gland-specific protein associates with chitin, and that freshly attached cyprids can be removed from surfaces using chitinase.
Domaine de référence : Antifouling
Auteur Aldred Nick, Chan Vera Bin San, Emami Kaveh, Okano Keiju, Clare Anthony S., Mount Andrew S.
Année de parution : 2020.
Type de document : Article de revue.
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Prevention of biofouling on aquaculture nets with eco-friendly antifouling paint formulation

Résumé : Aquaculture, which is an important part of food supply, is usually carried out in cage nets made of textile materials. Fouling organisms settle on the cage nets over time, close the mesh openings, and cause unwanted weight gain. In order to prevent fouling, aquaculture nets are generally treated with antifouling paints. In this paper, warp knitted cage nets made from various raw materials were treated with three different antifouling paints. Econea was used as a biocide to prepare an eco-friendly antifouling paint formulation, and two copper-based commercial antifouling paints were supplied for comparison. Antifouling paint-treated and untreated net samples were immersed in a marine ecosystem next to an aquaculture zone for 6 months. Settlement of fouling organisms on nets was observed by taking underwater photographs at periodic intervals. Following the field study, changes in the structure of the nets and antifouling performance of the paints were evaluated considering the results of underwater photographs, biomass growth, variation in mass and strength tests. Colour fastness of the antifouling paints to sea water was also measured to learn about biocide release and surface hydrophobicity. The results show that copper-free eco-friendly antifouling paint is just as effective against the fouling mechanism for all types of nets as copper-based commercial antifouling paints. The novel eco-friendly formulation has promising results, which provides an alternative for producers when considering the selection of raw materials.
Domaine de référence : Antifouling
Auteur Sen Korhan, Erdogan Umit Halis, Cavas Levent
Année de parution : 2020.
Type de document : Article de revue.
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Antibiofouling potential of 1-alkyl-3-methylimidazolium ionic liquids : Studies against biofouling barnacle larvae

Résumé : Development of novel and environmental-friendly antifouling compounds is desirable due to the ban on use of tributyltin and concerns on copper and co-biocides. In the current study, antimacrofouling effects of alkylimidazolium ionic liquids on Amphibalanus (=Balanus) reticulatus, a dominant fouling barnacle were assessed. The effect of three alkylimidazolium ionic liquids ([CnMIM]+[X]−, n = 4, 12 and 16) on survival, metamorphosis and settlement of barnacle larvae (nauplii and cypris) was determined in laboratory bioassays. Among the tested ionic liquids, [C12MIM][I] exhibited superior antibiofouling activity with a cypris mortality (LC50) and settlement inhibition (EC50) concentrations of 0.35 μM and 0.39 nM, respectively. [C16MIM][Cl] showed moderate activity with LC50 and EC50 values of 0.63 μM and 1.56 nM, respectively. However, [C4MIM][Cl] exhibited lowest activity on survival and settlement with LC50 and EC50 values of 2.28 μM and 80.2 nM, respectively. The anion (Cl− or I−) did not contribute to the biological activity of ionic liquids. Antifouling activity of the tested ionic liquids on larvae decreased in the following order: [C12MIM][I] > [C16MIM][Cl] > [C4MIM][Cl]. Therapeutic ratios (TR = LC50/EC50) of the tested compounds at >28 to 900 were found to be much higher than the reference value (>15) qualifying them as promising non-toxic or environmentally benign antifoulants. Tested ionic liquids exhibited activity in the similar order ([C12MIM][I] > [C16MIM][Cl] > [C4MIM][Cl]) on survival and metamorphosis of nauplius larvae. EC50 and LC50 concentrations of all the three compounds had no lethal effect on non-target organism, Artemia salina. These data presents possibilities for designing effective and environmental friendly antifouling strategies.
Domaine de référence : Antifouling
Auteur Reddy G. Kiran Kumar, Rajitha K., Nancharaiah Y. V.
Année de parution : 2020.
Mots-clés : Biofouling, Larval settlement, Macrofouling control, Metamorphosis, Non-toxic antifoulants, Settlement inhibition.
Type de document : Article de revue.
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Antibiofilm activity in the culture supernatant of a marine Pseudomonas sp. bacterium

Résumé : In the marine environment, most solid surfaces are covered by microbial biofilms, mainly composed of bacteria and diatoms. The negative effects of biofilms on materials and equipment are numerous and pose a major problem for industry and human activities. Since marine micro-organisms are an important source of bioactive metabolites, it is possible that they synthesize natural ecofriendly molecules that inhibit the adhesion of organisms. In this work, the antibiofilm potential of marine bacteria was investigated using Flavobacterium sp. II2003 as a target. This strain is potentially a pioneer strain of bacteria that was previously selected from marine biofilms for its strong biofilm-forming ability. The culture supernatants of 86 marine heterotrophic bacteria were tested for their ability to inhibit Flavobacterium sp. II2003 biofilm formation and the Pseudomonas sp. IV2006 strain was identified as producing a strong antibiofilm activity. The Pseudomonas sp. IV2006 culture supernatant (SNIV2006) inhibited Flavobacterium sp. II2003 adhesion without killing the bacteria or inhibiting its growth. Moreover, SNIV2006 had no effect on the Flavobacterium sp. II2003 cell surface hydrophilic/hydrophobic and general Lewis acid–base characteristics, but modified the surface properties of glass, making it on the whole more hydrophilic and more alkaline and significantly reducing bacterial cell adhesion. The glass-coating molecules produced by Pseudomonas sp. IV2006 were found to probably be polysaccharides, whereas the antibiofilm molecules contained in SNIV2006 and acting during the 2 h adhesion step on glass and polystyrene surfaces would be proteinaceous. Finally, SNIV2006 exhibited a broad spectrum of antibiofilm activity on other marine bacteria such as Flavobacterium species that are pathogenic for fish, and human pathogens in both the medical environment, such as Staphylococcus aureus and Pseudomonas aeruginosa , and in the food industry, such as Yersinia enterocolitica . Thus, a wide range of applications could be envisaged for the SNIV2006 compounds, both in aquaculture and human health
Domaine de référence : Antifouling
Auteur Doghri Ibtissem, Brian-Jaisson Florence, Graber Marianne, Bazire Alexis, Dufour Alain, Bellon-Fontaine Marie-Noëlle, Herry Jean-Marie, Ferro Ana Caroline, Sopena Valérie, Lanneluc Isabelle, Sablé Sophie
Année de parution : 2020.
Type de document : Article de revue.
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Random array of inorganic nanoparticles on polymer surface for anti-biofouling property through cost-effective and high-performance dip-coating

Résumé : Anti-biofouling treatment is required in various fields such as biomedical application, construction, civil engineering, and so on. Currently available techniques such as lithography and replica methods have several limitations in application and accessibility. We introduced a simple, biocompatible, and cost-effective anti-biofouling dip-coating method with polyurethane-inorganic (anisotropic montmorillonite and spherical TiO2) hybrid coating agent. Layer thickness of coating was as thin as 5 μm. It was cross-confirmed with thickness gauge and cross-section scanning electron microscopy. Through atomic force microscopy, inorganic nanoparticles were observed to be randomly arrayed with particles partially embedded in the polyurethane network. The calculated surface roughness of inorganic-polyurethane hybrid coating was five times larger than the neat substrate film and three times larger than coating without inorganic nanoparticles. Surface energy of the inorganic-polyurethane film decreased with increasing surface roughness as random pattern of inorganic particle reduced van der Waals interaction. Biofouling efficacy was evaluated by mucin adsorption and consecutive alcian blue assay. Results showed that coated film decreased biofouling 81% compared to bare film.
Domaine de référence : Antifouling
Auteur Kim Hyoung-Jun, Jeung Do-Gak, Oh Jae-Min
Année de parution : 2020.
Mots-clés : Anti-biofouling, Dip-coating, Inorganic nanoparticles, Patterning.
Type de document : Article de revue.
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Reduction of Microalgae by Cupper Ion In Impressed Current Anti Fouling System for Biofouling Prevention in Saline Environment

Résumé : The biofouling cause coorosion in marine environment or it is called as biological corrosion. The biological corrosion occur in the metal material both on coastal buildings, offshore buildings, port buildings and shipboard. One method to prevent the biological corrosion is ICAF (Impressed Current...
Domaine de référence : Antifouling
Auteur Pratikno Herman, Titah Harmin Sulistiyaning, Handayanu Handayanu
Année de parution : 2020.
Type de document : Article de revue.
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Small-Scale Effects of Offshore Wind-Turbine Foundations on Macrobenthic Assemblages in Pinghai Bay, China

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Résumé : Several unicellular microorganisms use small signalling molecules to find out their local concentration. The processes involved in the production andrecognition of these signals are generally known as quorum sensing (QS). Unicellular microorganisms to manage their activities use this kind of cellto- cell communication, which allows them to work as multi-cellular systems. Newly, several groups have confirmed artificial intra species and inter-species communication through synthetic circuits, which incorporate components of bacterial QS systems
Domaine de référence : Antifouling
Auteur Aziz Malik Asif, Lone Shazia, Ah. Malik Mushtaq, Dar Zaffar Mahdi, Masood Amjad, Shafi Saima, Sidique Showkat
Année de parution : 2019.
Type de document : Article de revue.
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Ce projet est financé par le Fonds Européen de Développement Régional, la Région Normandie et le Conseil Départemental de la Manche.