1,721,352 research outputs found
A study of the piezoresistive effect in thick-film resistors and its application to load transduction
No full textInexpensive, accurate, robust transducers have been sought for a long time, particularly for load sensing applications. Most attempts to produce such a device have suffered from significant trade offs, especially between cost and accuracy. The two main factors which contribute to the relatively high cost of loadcells are the cost of the primary sensor and the cost of machining the billet to reduce effects due to the eccentricity of loading. A new type of strain sensor based on the piezoresistive properties of thick-film resistors is described. Characterisation of the sensing element has revealed that the gauge factor is significantly higher than that of a metal foil strain gauge and the temperature coefficients are lower than those found for a semiconductor strain gauge. Results show how the gauge factor can be optimised by varying the production parameters. A loadcell based on thick-film strain gauges is also described. The design is such that the problems of eccentric loading are virtually eliminated. The technology also allows the associated electronics to be incorporated into the sensor housing.</p
Design and testing of a thick-film dual-modality sensor for composition measurements in heterogeneous mixtures
No full textThe current paper focuses on design and laboratory evaluation of a dual-modality sensor, developed for the needs of oil and gas extraction industry to measure the composition of heterogeneous mixtures in harsh conditions. The sensor combines ultrasonic and electrical measurement techniques, which are non-destructive, rapid and can potentially provide an on-line industrial measurement. Such a ‘dual-modality’ measurement could potentially be reliable in a wider range of process conditions. A distinct feature of the sensors presented here is their construction, which makes use of the thick-film technology, enabling the construction of multi-layered structures of both conductive and non-conductive layers, some of which may exhibit piezoelectric properties for ultrasonic measurement purposes. These are later fired on a ceramic substrate to provide rugged sensors, capable of working in aggressive industrial environments. Laboratory experiments to investigate the feasibility of the dual-modality sensors were conducted and some comparisons with the theoretical predictions are presented
Energy harvesting: an overview of techniques for use within the transport industry
Full text linkThis article introduces the various energy harvesting mechanisms that can be used to energize sensing systems and associated wireless communication channels. It outlines energy scavenging techniques, along with an assessment of useful materials for each mode of harvesting
MEMS for automotive and aerospace applications
No full textMEMS for automotive and aerospace applications reviews the use of Micro-Electro-Mechanical-Systems (MEMS) in developing solutions to the unique challenges presented by the automotive and aerospace industries.Part one explores MEMS for a variety of automotive applications. The role of MEMS in passenger safety and comfort, sensors for automotive vehicle stability control applications and automotive tire pressure monitoring systems are considered, along with pressure and flow sensors for engine management, and RF MEMS for automotive radar sensors. Part two then goes on to explore MEMS fo
Implementation of the Straightening Algorithm of Classical Invariant Theory
No full textWhite, Neil. (1988). Implementation of the Straightening Algorithm of Classical Invariant Theory. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/4875
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