In this article, it is shown that focused ion beam (FIB) systems can be used to study the inner structure of flax fibers, the use of which as a reinforcing material in polymer composites still draws much interest from multiple disciplines. This technique requires none of the specific preparations necessary for scanning electron microscopy or transmission electron microscopy studies. Irradiation experiments performed on FIB prepared cross sections with very low Ga+ ion beam currents revealed the softer material components of fibers. Thus, it confirmed the presence of pectin-rich layers at the interfaces between the fibers of a bundle, but also allowed the precise localization of such layers within the secondary cell wall. Furthermore, it suggested new insights on the transition modes between the sublayers of the secondary cell wall.
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http://dx.doi.org/10.1017/S1431927609991292 | DOI Listing |
Appl Radiat Isot
January 2025
Johannes-Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany.
Precise measurements of fundamental decay data such as energies and transition probabilities of radioactive isotopes are important for the development of corresponding nuclear modelling, activity determination and various applications in science and technology. The EMPIR project PrimA-LTD -"Towards new Primary Activity standardisation methods based on Low-Temperature Detectors" - aims to measure the electron-capture decay of Fe very precisely using Metallic Microcalorimeters (MMCs) with outstandingly high energy resolution. Using a high-statistics measurement, electron-capture probabilities shall be precisely determined and higher-order effects such as electron shake-up and shake-off shall be examined with unprecedented precision.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Institute for Physical Chemistry, University of Göttingen, 37077 Göttingen, Germany.
Surface science instruments require excellent vacuum to ensure surface cleanliness; they also require control of sample temperature, both to clean the surface of contaminants and to control reaction rates at the surface, for example, for molecular beam epitaxy and studies of heterogeneous catalysis. Standard approaches to sample heating within high vacuum chambers involve passing current through filaments of refractory metals, which then heat the sample by convective, radiative, or electron bombardment induced heat transfer. Such hot filament methods lead to outgassing of molecules from neighboring materials that are inadvertently heated; they also produce electrons and ions that may interfere with other aspects of the surface science experiment.
View Article and Find Full Text PDFHeliyon
January 2025
Division of Polymer Chemistry, Department of Chemistry, Atomic Energy Commission, P.O. Box: 6091, Damascus, Syrian Arab Republic.
The degree of sulfonation (DS) is a key property of sulfonated polymers, as it significantly influences their swelling behaviour, conductivity and mechanical properties. Accurately determining the DS is essential for optimizing these materials for various applications. In this work, the DS of sulfonated poly (ether ether ketone) (SPEEK) was evaluated using a combination of analytical techniques, including titration, back titration, Fourier Transform Infrared (FTIR), Ultra-Violet (UV) and proton nuclear magnetic resonance (H NMR) spectroscopies, Thermogravimetric analysis (TGA), Rutherford backscattering (RBS) and particle induced X-ray emission (PIXE) analysis.
View Article and Find Full Text PDFRadiat Oncol
January 2025
ISTCT UMR 6030-CNRS, Université de Caen-Normandie, Caen, France.
Background: Radiotherapy as a complement or an alternative to neurosurgery has a central role in the treatment of skull base grade I-II meningiomas. Radiotherapy techniques have improved considerably over the last two decades, becoming more effective and sparing more and more the healthy tissue surrounding the tumour. Currently, hypo-fractionated stereotactic radiotherapy (SRT) for small tumours and normo-fractionated intensity-modulated radiotherapy (IMRT) or proton-therapy (PT) for larger tumours are the most widely used techniques.
View Article and Find Full Text PDFSci Rep
January 2025
Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Orgánica, IMEYMAT, Universidad de Cádiz, Campus Río San Pedro, 11510, Puerto Real, Cádiz, Spain.
Polymer blending is an interesting strategy to broaden the combination of properties available for a variety of applications. To understand the behaviour of the new materials obtained as well as the influence of the fabrication parameters used, methods to analyse the distribution of polymers in the blend with resolution below the micrometer are required. In this work, we demonstrate the capability of focused ion beam (FIB) tomography to provide 3D information of the polymer distribution in objects obtained by blending acrylonitrile-styrene-acrylate (ASA) with polycarbonate (PC) (50 wt%), fabricated by Fused Filament Fabrication (FFF) and by Injection Moulding (IM).
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