1,721,175 research outputs found
Structural Monitoring System for proactive detection of corrosion and coating failure
No full textThe performance and availability of high priority structures can be greatly affected by corrosion damage. The application of protective coatings, frequent inspections and scheduled based maintenance activities result in huge direct and indirect financial loss to organisations. The expeditious detection of coating failure and corrosion damage can result in precise and cost-effective condition-based maintenance. Coating failure and corrosion phenomena are driven by complex multi-disciplinary parameters according to extensive research findings in the literature. State-of-the-art prognostic models proposed in recent years incorporate complex multi-disciplinary parameters, therefore a real-time prognostic monitoring system must acquire these complex parameters to allow accurate prediction. The work reported here covers the development of a real-time monitoring system using micro-sensors and includes the validation of the system through accelerated corrosion and coating failure testing. The system contains a remote terminal unit that includes a linear polarisation method for corrosion detection under the coating and a micro-strain gauge method for monitoring stress behaviour over the coating. The software at base station includes a graphical user interface and database to store parameters for further processing and failure prediction. The real-time monitoring system can be applied to remote, stationary and mobile assets to monitor the mechanical and chemical changes within coating-substrate systems
Rapid manufacture of integrated self-powered sensing systems using additive manufacturing for critical structure health monitoring
No full textIn this project, the feasibility of rapid manufacturing of integrated corrosion monitoring sensing systems within critical engineering structural components using advanced AM technologies has been demonstrated with an exemplar model structure of crevice corrosion monitoring with integrated carbon-based electrochemical sensors. Corrosion performance of all five different materials model crevice former structures built using different AM technologies have been investigated for the first time in a 3.5% NaCl test solution, and the tests results provide the guidelines for the selection of appropriate AM technologies for rapid manufacturing engineering structures in corrosive environment applications. The model crevice corrosion monitoring structure and the rapid manufacturing approaches achieved in this project also provide proof of the concept for design and rapid manufacturing of functionalised engineering components with self-powered embedded structural health monitoring devices
Dataset for "The effect of age on technique variability and outcome variability during a leg press"
Full text linkPower, velocity and lower-limb joint coordination variability dat
Challenges and developments of self-assembled monolayers and polymer brushes as a green lubrication solution for tribological applications
No full textSelf-assembled monolayers (SAMs), after originally being investigated due to their functions in changing surface wettability, have been significantly developed over the years. Many types of SAMs have been developed on a variety of substrates. However their formation mechanism, rate and quality are found to be influenced by many factors. A range of SAMs including single- and multi- component are included in this review with focus on the nano and macro tribological properties. More recently, surface initiated polymer brushes, i.e. macromolecular assemblies attached to a substrate, have emerged to be an alternative and promising method for surface modification. The ability to tether these macromolecules to tribological contacts is key to their resistance to shear under loaded contacts. This review also covers atom transfer radical polymerisation (ATRP) and the role of this technique in developing new lubrication solutions. Particular care has been taken to include the development of lubrication solutions for silicon nitride due to the importance of this material as an engineering ceramic. This paper reviews the state-of-the-art development of SAMs and polymer brushes especially the potential opportunities and challenges in applying them in tribological contacts as a lubrication solutio
Polymer brushes for silicon nitride-steel contacts: a colloidal force microscopy study
No full textA greener lubrication solution based on self-assembling methods for steel on silicon nitride hybrid contacts is investigated in this study. Surface initiated atom transfer radical polymerisation (ATRP) is employed to produce oleophilic polymer brushes based on methyl methacrylate (MMA). This paper presents the synthesis and characteristics of poly(MMA) brushes that have been designed to synergize with a PAO lubricant whilst forming a strong covalent bond with the silicon nitride surface. By utilising activators regenerated by electron transfer (ARGET) the amount of catalyst needed is reduced to ppm levels allowing polymerisations to take place in a limited amount of air. The initiators and the polymer brushes formed on silicon nitride surfaces are characterised using XPS, contact angle, gel permeation chromatography and atomic force microscopy. The lubricating effects of the polymer brushes under dry and swollen states are evaluated using lateral force microscopy with a steel colloid
Electrochemical behaviour of nickel–aluminium bronze in chloride media: influence of pH and benzotriazole
No full textThe corrosion properties of the nickel–aluminium bronze (NAB) in aqueous chloride media were investigated at different pHs by using linear potential sweep voltammetry and scanning electron microscopy. The NAB electrochemical behaviour was dependent on the solution pH, due to the different stabilities of the phases present within its microstructure. In particular, at solution pHs higher than 4.0 the NAB oxidation was driven by the dissolution of the copper-rich ?-phase, whereas at pH values lower than 4.0 its anodic behaviour was controlled by the oxidation of the iron-, nickel- and aluminium-rich ?I-, ?II- and ?IV-phases. Furthermore, a kinetic model for the NAB oxidation, in neutral chloride solutions, was developed on the basis of the observed behaviour, i.e., order of reactions of NAB with respect to protons and chloride. Finally, considering the high affinity of benzotriazole for copper, the corrosion performance of NAB was studied in the presence of the inhibitor in neutral (pH of 6.2) and acidic (pH of 3.5) chloride solutions, where NAB exhibited different anodic behaviours
Data set for 'Habitual physical activity levels do not predict leg strength and power in healthy, active older adults'
Full text linkThis dataset contains basic participant characteristics (age, height, weight, BMI, vastus lateralis msucle thickness), physical function characteristic (Short Physical Performance Battery scores, and velocity, force, and power variables of leg pressing performance), and habitual physical activity level provided as daily energy expenditure/basal metabolic rate and time spent in age determined physical activity thresholds, for healthy older versus younger adults. This dataset is to accompany the manuscript 'Habitual physical activity levels do not predict leg strength and power in healthy, active older adults' submitted for publication to the journal PLOS ONE
Electrochemical sensing and characterization of aerobic marine bacterial biofilms on gold electrode surfaces
Full text linkReliable and accurate in situ sensors capable of detecting and quantifying troublesome marine biofilms on metallic surfaces are increasingly necessary. A 0.2 mm diameter gold electrochemical sensor was fully characterised using cyclic voltammetry in abiotic and biotic artificial seawater media within a continuous culture flow cell to detect the growth and development of an aerobic Pseudoalteromonas sp. biofilm. Deconvolution of the abiotic and biotic responses enable the constituent extracellular electron transfer and biofilm responses to be resolved. Differentiation of enhanced oxygen reduction kinetics within the aerobic bacterial biofilm are linked to enzyme and redox mediator activitie
Monitoring Aerobic Marine Bacterial Biofilms on Gold Electrode Surfaces and the Influence of Nitric Oxide Attachment Control
Full text linkDetection of aerobic
marine bacterial biofilms using
electrochemical
impedance spectroscopy has been done to monitor the interfacial response
of Pseudoalteromonas sp. NCIMB 2021
attachment and growth in order to identify characteristic events on
a 0.2 mm diameter gold electrode surface. Uniquely, the applicability
of surface charge density has been proven to be valuable in determining
biofilm attachment and cell enumeration over a 72 h duration on a
gold surface within a modified continuous culture flow cell (a controlled
low laminar flow regime with Reynolds number ≈ 1). In addition,
biofilm dispersal has been evaluated using 500 nM sodium nitroprusside,
a nitric oxide donor (nitric oxide is important for the regulation
of several diverse biological processes). Ex situ confocal microscopy
studies have been performed to confirm biofilm coverage and morphology,
plus the determination and quantification of the nitric oxide biofilm
dispersal effects. Overall, the capability of the sensor to electrochemically
detect the presence of initial bacterial biofilm formation and extent
has been established and shown to have potential for real-time biofilm
monitoring
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