This paper describes a novel quartz crystal sensor for measurement of the density-viscosity product of Newtonian liquids. The sensor element consists of two piano-convex AT-cut quartz crystals vibrating in a thickness-shear mode with the liquid sample in between. This special set-up allows suppression of disturbing resonances in the liquid layer. Such resonances are generated in the common single-plate arrangements due to compressional waves caused by spurious out-of-plane displacements of the shear vibrating finite plate. The primary measurands of the sensor are the fundamental resonance frequency and the associated resonance Q-value, which are influenced by the viscously entrained liquid contacting the quartz surface. The sensor allows the measurement of samples with viscosities from almost zero (air!) up to 200 cP with a sample volume of 130 microl.
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http://dx.doi.org/10.1109/58.726459 | DOI Listing |
Micromachines (Basel)
January 2025
Department of Mechanical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal.
Magnetic field-assisted control of magnetite location is a promising strategy for developing flexible, electrically conductive sensors with enhanced performance and adjustable properties. This study investigates the effect of static magnetic fields applied on thermoplastic elastomer (TPE) composites with magnetite and multi-walled carbon nanotubes (MWCNT). The composites were prepared by compression moulding and the magnetic field was applied on the mould cavity during processing.
View Article and Find Full Text PDFChem Asian J
January 2025
Birla Institute of Technology & Science Pilani - Hyderabad Campus, Chemistry, Jawaharnagar, Shamirpet Mandal, 500078, Hyderabad, INDIA.
Despite significant advancements in the structural flexibility and functional diversity of fluorescent molecular sensors, the chromophores often require complex synthetic processes and are typically designed to perform only a specific function. Herein, we have demonstrated the unique features of fluorophores based on a fused coumarin-indole scaffold, which are synthetically available via a one-step reaction. Four fluorophores (ICH, ICEst, ICOMe, and ICNMe2) with varying substituents were synthesized and characterized.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Bristol Composites Institute, School of Civil, Aerospace, and Design Engineering, University of Bristol, University Walk, Bristol BS8 1TR, UK. Electronic address:
Cellulose nanocrystals (CNCs) have emerged as promising, sustainable materials, with applications in sensors, coatings, pharmaceuticals, and composites. Their modification with block copolymers such as PEO-PPO-PEO triblock copolymers of the Pluronic family has been attempted many times in the literature, with claims that such modification would happen by an anchor(PEO)-buoy(PPO)-anchor(PEO) mechanism. However, there is much disagreement in the literature on this.
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December 2024
Institute of Fundamental Technological Research, Polish Academy of Sciences, ul. Pawińskiego 5B, 02-106 Warsaw, Poland.
In this paper, we demonstrate that torsional surface elastic waves can propagate along the curved surface of a metamaterial elastic rod (cylinder) embedded in a conventional elastic medium. The crucial parameter of the metamaterial rod is its elastic compliance s44(1)ω, which varies as a function of frequency ω analogously to the dielectric function εω in Drude's model of metals. As a consequence, the elastic compliance s44(1)ω can take negative values s44(1)ω<0 as a function of frequency ω.
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December 2024
Research Department of Imaging Physics and Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, London WC2R 2LS, UK.
MR elastography is a non-invasive imaging technique that provides quantitative maps of tissue biomechanical properties, i.e., elasticity and viscosity.
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