345 research outputs found

    CMOS current attenuator for electrochemical sensing applications

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    Understanding the Impact of Technology: Learner and School Level Factors

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    The first part of this report focuses on the factors impacting on learner performance in national tests at primary and secondary level. This was the central research question of this research. The second section focuses on teacher and learner perceptions of their own responses to learning and the learning environment. This was centred on, but not confined to, their school. The institutional structures record the level of development of the schools sampled here and investigate the use of two key technologies – interactive whiteboards and learning platform

    Spatiotemporal Electrochemical Sensing in a Smart Contact Lens

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    An electrochemical smart contact lens (ESCL) capable of real-speed spatiotemporal electrochemical sensing across the surface of the eye is demonstrated. Four microelectrode arrays, each comprising 33 gold microdiscs of 30 ÎŒm diameter, and a distributed common gold counter electrode, are integrated into a soft smart contact lens platform based on polyimide and thermoplastic polyurethane. Using a novel fast-switching chronoamperometric method, an electrochemical ‘video’ of concentration variation in a model eye under ïŹ‚ow conditions is produced, in which the introduction, progress, mixing and drainage of ïŹ‚uid of varying concentration can be observed. The device builds on previous work towards a platform suitable for clinical use and has proven to be robust under expected use conditions, with sensing performance remaining unchanged after thermoforming and repeated mechanical deformation. This work represents a signiïŹcant step forward in ESCL design, and constitutes sig- niïŹcant progress towards a technology with real clinical utility

    A Novel Contactless Technique to Measure Water Waves Using a Single Photon Avalanche Diode Detector Array

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    Commonly deployed measurement systems for water waves are intrusive and measure a limited number of parameters. This results in difficulties in inferring detailed sea state information while additionally subjecting the system to environmental loading. Optical techniques offer a non-intrusive alternative, yet documented systems suffer a range of problems related to usability and performance. Here, we present experimental data obtained from a 256 × 256 Single Photon Avalanche Diode (SPAD) detector array used to measure water waves in a laboratory facility. 12 regular wave conditions are used to assess performance. Picosecond resolution time-of-flight measurements are obtained, without the use of dye, over an area of the water surface and processed to provide surface elevation data. The SPAD detector array is installed 0.487 m above the water surface and synchronized with a pulsed laser source with a wavelength of 532 nm and mean power <1 mW. Through analysis of the experimental results, and with the aid of an optical model, we demonstrate good performance up to a limiting steepness value, ka, of 0.11. Through this preliminary proof-of-concept study, we highlight the capability for SPAD-based systems to measure water waves within a given field-of-view simultaneously, while raising potential solutions for improving performance
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