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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"Fibre optic sensors"”.
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Interrogation of fibre optic sensors
… thesis was to investigate the interrogation of fibre optic sensors using "off the shelf optical components and equipment developed mainly for the telecommunications industry. This provides a cost effective way of bringing fibre optic sensor systems to within the price range of their …
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Modified Hydrogel Matrices in Fibre Optic Sensors
… device. The latter, also applying to chemical sensors, is possibly due to a lack of understanding of polymer support or membrane properties and hence failure to optimise membranes chosen for specific sensor applications. Hydrogels can be described as polymers which swell in water. In addition …
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Characterisation of cross-linking and moisture ingress detection in an epoxy/amine resin using fibre-optic sensors
… increasingly as matrix materials in advanced fibre-reinforced composites. It is well known that the processing conditions used to manufacture the composite can have a major influence on its mechanical integrity in service. In addition, the processing parameters can also affect the ingress of …
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Studies of measurement techniques for indirect chemical sensing based on fluorescence spectroscopy and applications for fibre-optic sensors
… was 500±25pW).<br/>A novel combination of ruby optical temperature sensor insert and oxygen sensing layer was demonstrated as a simultaneous temperature and oxygen sensor.<br/>A new fluorescence calibration standard consisting of thermally stabilised titanium-doped sapphire sample was …
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Fibre Optic Sensors for Tumour Therapy Monitoring. Applications of Optical Fibre Sensing Technologies to Thermal and Radiotherapy Treatments of Neoplasms
L'abstract è presente nell'allegato / the abstract is in the attachment
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Distributed Fibre Optic Sensing to Assess Support Reactions and Behaviour of Composite Steel Bridges
… in this investigation involves using distributed fibre optic sensing (DFOS) strain measurements to estimate support reactions in beams through an experimental investigation that involved beam, model bridge, and field load tests. Five steel beams were instrumented with fibre optic sensors and …
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Evaluation of the Flexural Response of Steel Reinforced UHP-FRC Beams Using Distributed Sensing
The interaction between ultra-high-performance fibre-reinforced concrete (UHP-FRC) and steel reinforcement significantly affects the displacement ductility of UHP-FRC beams in flexure, leading to a brittle failure mechanism due to crack localization. Previous studies faced limitations in fully …
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Design and characterisation of long period grating (LPG) - based optical fibre sensors for acoustic wave detection
Fibre optic sensors have demonstrated a broad range of commercial potential due to their intrinsic characteristics such as low loss, very small size, light weight and immunity to electromagnetic interference. Representing one type of optical fibre sensors, long period gratings (LPGs) have shown a …
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Fibre optic pressure sensor for downhole monitoring in the oil industry
… be 35% on average for North Sea oil-wells.<br/>Fibre-optic sensors have the potential to measure many downhole parameters. However, high-temperature, high-pressure (HTHP) fluids are shown to have adverse effects on fibre pressure-sensors and cables. All unprotected, silica-fibre, pressure …
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Fibre optic sensing techniques for the detection of lead (II) ions
… of two lead-sensitive reagents in different fibre optic sensing configurations. The reagents were carefully selected for their response towards lead. A probe was built for each reagent and a sensor system designed, constructed and tested with each probe followed by analysis of the …
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Distributed Sensing for Monitoring Cast Iron Pipe Behaviour
… of 2.2 m, were instrumented with distributed fibre optic sensors (three circumferential fibres around midspan and five longitudinal fibres along the crown, springlines, and invert) and tested in four-point bending to identify the circumferential and longitudinal strain distributions before …
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Distributed feedback fibre laser strain and temperature sensors
… types of polarimetric distributed feedback (DFB) fibre laser sensors for simultaneous strain and temperature measurements. These fibre Bragg grating (FBG) based sensors offer strain and temperature measurement accuracies of ±0.3 - ±15 µ.epsilon and ±0.04 - ±0.2°C which are suitable for many …
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Distributed Sensing to Assess the Shear Behaviour of Reinforced Concrete Beams
… and the effects of deterioration. Distributed fibre optic sensors (FOS) based on measuring Rayleigh backscatter provide strain measurements along the full length of the fibre up to 70 m. Digital image correlation (DIC) can show crack formation over the surface of a structure and assist with the …
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Application of acoustic emission sensing for the non-destructive evaluation of advanced composite materials
… material (CFRP) is achieved using an all-fibre Mach-Zehnder interferometric sensor. The basic Mach-Zehnder configuration was modified to achieve the sensitivity needed to detect the low amplitude signals associated with AE. An active homo dyne feedback loop was employed to maintain …
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Cross sensitivity analysis of optical fibre-based sensing for high pressure, high temperature measurement in oil and gas applications.
… wells could reach beyond 300 °C and 20000 kPa. Fibre optic sensor developments have created new interest in oil and gas production monitoring and control. Fibre optic sensors currently deployed in the oil and gas industry can only operate up to 150 °C and even the most robust sensors are limited …
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Shear Behaviour in Slender Reinforced Concrete Beams with and without Transverse Reinforcement
… transverse steel. Comparisons with DIC and fibre optic sensors (FOS), experimental strain measurements are used to inform the selection of representative values. The RC beams without transverse steel utilise the average concrete strain within the web from the simplified modified compression …
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Experimental and theoretical analysis of polarization-maintaining fibre for sensing applications
Fibre optic sensors have been developed extensively over the past several decades, showing their potential and suitability for real-time measurement and thus meeting various industrial challenges. This has been achieved through the continuous innovation both in the fibre structural design and in …
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Investigations on the development of a novel hybrid sensor for environmental monitoring applications.
… in-situ, rapid, highly sensitive and selective sensors to monitor the very low concentration levels. Various approaches for improving sensitivity and selectivity have been investigated over the years involving multiple detection techniques. In general, optical approaches provide higher …
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Investigations towards the development of a novel multimodal fibre optic sensor for oil and gas applications.
… at longer distances. Traditional electrical sensors operate less effectively under these extreme environmental conditions and are susceptible to electromagnetic interference (EMI). Compared to electrical sensors, fibre optic sensors offer several advantages like immunity to EMI, electrical …
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Dynamic Strain Measurement Using Brillouin Optical Time-Domain Reflectometry
… the Brillouin scattering based distributed fibre optic sensors have attracted significant attentions in recent decades. These sensors can quantitatively measure the distributed strain and temperature information along the optic fibre. The Brillouin optical time-domain reflectometry (BOTDR) …
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