Nano-CaF2, prepared by the co-precipitation method, was annealed under different annealing conditions to improve its thermoluminescence (TL) characteristics. Different annealing parameters, such as temperature (400-700°C), duration (1-4 h) and environment (vacuum and air), were explored. The effect on TL sensitivity, peak position (Tm) and full-width at half-maximum (FWHM) with respect to the different annealing conditions are discussed as they are the measure of crystallinity of the material. Annealing temperature of 500°C with annealing duration of two and a half hours in vacuum provided the highest luminescence response (i.e. maximum sensitivity, minimum peak temperature and FWHM). Wide detectable dose range (5 mGy to 2 kGy), absence of thermal quenching and sufficient activation energy (1.04 eV) of this phosphor make it suitable for dosimetric applications.
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http://dx.doi.org/10.1093/rpd/ncu333 | DOI Listing |
ChemSusChem
January 2025
Brandenburgische Technische Universitat Cottbus-Senftenberg, Angewandte Physik und Halbleiterspektroskopie, Konrad-Zuse-Str. 1, 03046, Cottbus, GERMANY.
Ultrathin atomic layer deposited ceria films (< 20 nm) are capable of H2 heterolytic activation at room temperature, undergoing a significant reduction regardless of the absolute pressure, as measured under in-situ conditions by near ambient pressure X-ray photoelectron spectroscopy. ALD-ceria can gradually reduce as a function of H2 concentration under H2/O2 environments, especially for diluted mixtures below 10%. At room temperature, this reduction is limited to the surface region, where the hydroxylation of the ceria surface induces a charge transfer towards the ceria matrix, reducing Ce4+ cations to Ce3+.
View Article and Find Full Text PDFNanoscale
January 2025
Center for Energy and Environmental Sciences, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland.
The strong influence of surface adsorbates on the morphology of a catalyst is exemplified by studying a silver surface with and without deposited zinc oxide nanoparticles upon exposure to reaction gases used for carbon dioxide hydrogenation. Ambient pressure X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements indicate accumulation of carbon deposits on the catalyst surface at 200 °C. While oxygen-free carbon species observed on pure silver show a strong interaction and decorate the atomic steps on the catalyst surface, this decoration is not observed for the oxygen-containing species observed on the silver surface with additional zinc oxide nanoparticles.
View Article and Find Full Text PDFFoods
December 2024
School of Public Health, Hebei Medical University, Shijiazhuang 050017, China.
Foodborne viruses are significant contributors to global food safety incidents, posing a serious burden on human health and food safety. In this study, a multiplex reverse transcription-droplet digital PCR (RT-ddPCR) assay based on the MS2 phage as a process control virus (PCV) was developed to achieve the simultaneous detection of hepatitis A virus (HAV) and hepatitis E virus (HEV) in bivalve shellfish. By optimizing the reaction system and procedures, the best reaction conditions were selected, and the specificity, sensitivity, and reproducibility of the method were assessed.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
E.T.S. de Ingeniería y Diseño Industrial, Universidad Politécnica de Madrid (España), 28040 Madrid, Spain.
Polymers are often insulators, but this not a universal intrinsic characteristic of all polymers. For this work, the adhesives used, epoxy and polyurethane, do demonstrate this insulating characteristic. However, there has been significant interest in the development of conductive polymers, specifically adhesives, because of the potential properties and ease of processing of these polymers.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Department of Materials, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Platinum (Pt)-based heterogeneous catalysts show excellent performance for the electrocatalytic hydrogen evolution reaction (HER); however, the high cost and earth paucity of Pt means that efforts are being directed to reducing Pt usage, whilst maximizing catalytic efficiency. In this work, a two-step laser annealing process was employed to synthesize Pt single-atom catalysts (SACs) on a MOF-derived carbon substrate. The laser irradiation of a metal-organic framework (MOF) film (ZIF67@ZIF8 composite) by rapid scanning of a ns pulsed infrared (IR; 1064 nm) laser across the freeze-dried MOF resulted in a metal-loaded graphitized film.
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