Search results for " tomography"
showing 7 items of 1487 documents
X-ray tomographic method for measuring three-dimensional deformation and water content distribution in swelling clays
2015
A non-invasive method for simultaneous measurement of the 3D displacement field and the water content distribution of a wetted solid material is developed. The method is based on comparison of X-ray tomographic images of a material sample in the reference state and in the wetted and deformed state. The deformation and water content analyses were successfully compared with numerical results for a cylindrical rubber test sample under axial compression, and with gravimetric results from axially wetted and sliced cylindrical bentonite samples, respectively. The methods were applied in a 4D study (three spatial dimensions and time) of wetting and deformation of purified swelling bentonite doped …
Composition and corrosion phases of Etruscan Bronzes from Villanovan Age
2008
A neutron diffraction (ND) and neutron tomography (NT) study of laminated ancient bronzes was performed at the ISIS (Rutherford Appleton Laboratory, UK) neutron source and at the BENSC reactor (Hahn-Meitner Institut, Germany). The samples are part of an 8th century BC Etruscan collection discovered in the necropolises of Osteria-Poggio Mengarelli and Cavalupo in the Vulci area (Viterbo, Italy). The study allowed us to derive-in a totally non-destructive manner-information related to the main composition of the objects, possible presence of alterations and their nature, crusts and inclusions, as well as structure of the bulk. The presence of some components is linked to a variety of question…
Pore and mineral structure of rock using nano-tomographic imaging
2015
ABSTRACTIn order to better understand the micrometer-scale structure of rock and its transport properties which arise from it, seven monomineral samples from two sites (Olkiluoto and Sievi, Finland) were studied with micro- and nanotomography and scanning electron microscopy. From the veined gneiss of Olkiluoto we studied biotite, potassium feldspar, plagioclase (composition of oligoclase) and cordierite, and from Sievi tonalite biotite and two grains of plagioclase (albite). These minerals were the main minerals of these samples. Samples were carefully separated and selected using heavy liquid separation and stereomicroscopy, their three dimensional structure was imaged using X-ray tomogra…
3D virtual Histopathology of Cardiac Tissue from Covid-19 Patients based on Phase-Contrast X-ray Tomography
2021
X-ray phase-contrast tomography datasets of formalin fixed paraffin embedded unstained cardiac tissue from Covid-19 patients as well as from control tissue. For each group one overview scan of the entire biopsy (3.5mm cross section) from binning and stitching different tomograms (PB bin2, voxel size: 1.3µm) as well as the respective laboratory data (LJ, voxel size: 2µm, tissue masked) and a cone-beam zoom tomogram recorded with waveguide illumination (WG, voxel size: 159 nm) is uploaded. Further datasets can be provided on request. The data has been recorded at the institute for X-ray physics (Göttingen, Germany) and DESY at the GINIX instrument, beamline P10 of the PETRAII…
X-ray tomographic method for measuring 3D deformation and liquid content in swelling materials
2015
A non-invasive method for measuring the three-dimensional displacement field and liquid content distribution in a wetting and swelling material using X-ray tomographic imaging is introduced. The method is demonstrated here in monitoring the evolution of 3D deformation and water content distributions in cylindrical samples of swelling clay material wetted in a constant total volume. The measurements were carried out using a high-resolution microtomographic device (SkyScan 1172) and image voxel size 24 µm. The results obtained are repeatable and appear qualitatively correct and plausible. They are useful e.g. in validating models involving transport of water and the resulting deformation of s…
Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry
2021
Radiation-sensitive gels are among the most recent and promising developments for radiation therapy (RT) dosimetry. RT dosimetry has the twofold goal of ensuring the quality of the treatment and the radiation protection of the patient. Benchmark dosimetry for acceptance testing and commissioning of RT systems is still based on ionization chambers. However, even the smallest chambers cannot resolve the steep dose gradients of up to 30–50% per mm generated with the most advanced techniques. While a multitude of systems based, e.g., on luminescence, silicon diodes and radiochromic materials have been developed, they do not allow the truly continuous 3D dose measurements offered by radiation-se…
Datortomogrāfijas vēdera dobuma izmeklējuma parametru pielāgošana pacientiem atkarībā no ķermeņa konstitūcijas
2015
Bakalaura darba tēma – vēdera dobuma DT izmeklējumu parametru pielāgošanas pacientiem pēc pacientu ķermeņa konstitūcijas. Tēmas aktualitāte ir liekā svara un adipozitātes gadījumu biežums Latvijas iedzīvotāju vidū. Kā liecina statistika: 2012. gadā 32% (vecumā no 15 līdz 64 g.) konstatēta adipozitāte, savukārt 18% iedzīvotāju – liekais svars (1). Darba mērķis ir: izvērtēt izmeklējumu parametru pielāgošanas iespējas pacientiem pie vēdera dobuma datortomogrāfijas izmeklējuma pēc pacientu ķermeņa konstitūcijas. Pētniecības uzdevumi ir: veikt literatūras analīzi par vēdera dobuma anatomiju, konstitūcijas tipiem, analizēt literatūru par DT darbības principiem, veikt pētījumu par ķermeņa konstitū…