Search results for "alkuaineanalyysi"
showing 5 items of 5 documents
Optimization of spodumene identification by statistical approach for laser-induced breakdown spectroscopy data of lithium pegmatite ores
2021
Mapping with laser-induced breakdown spectroscopy (LIBS) can offer more than just the spatial distribution of elements: the rich spectral information also enables mineral recognition. In the present study, statistical approaches were used for the recognition of the spodumene from lithium pegmatite ores. A broad spectral range (280–820 nm) with multiple lines was first used to establish the methods based on vertex component analysis (VCA) and K-means and DBSCAN clusterings. However, with a view to potential on-site applications, the dimensions of the datasets must be reduced in order to accomplish fast analysis. Therefore, the capability of the methods in mineral identification was tested wi…
Laser-induced time-resolved luminescence in analysis of rare earth elements in apatite and calcite
2021
Laser-induced time-resolved luminescence was used to study rare earth element (REE) containing natural apatite and calcite minerals. The luminescence from 400 nm to 700 nm in the minerals was analyzed with excitation ranges 210–340 nm and 405–535 nm. As an outcome, several useful excitation wavelengths to detect one or more REE from apatite and calcite are reported. The feasibility of selected excitations in e.g. avoiding the disturbance of intense Mn2+ luminescence band, results was demonstrated with a non-gated detector. peerReviewed
A new beamline for energy-dispersive high-resolution PIXE analysis using polycapillary optics
2019
Abstract A new beamline for high energy resolution PIXE measurements is presented. This new setup includes options for both in-air and vacuum measurements. For the high energy resolution transition-edge sensor array, a polycapillary lens is used for detecting low-energy X-rays down to 0.5 keV and to increase the effective solid angle. X-ray transmission of the polycapillary lens was characterized using two calibration standards. The gain obtained by adding a polycapillary lens was 1.6–2.3 at energies between 2.1 keV and 4.5 keV. From 1.04 to 1.74 keV the gain is increased to 2.1–3.0, and at energies 4.9–8.0 keV the gain is between 1.6 and 0.65. The measured gain agreed well with theoretical…
Hiilen taustavaikutukset muovien lisäaineille induktiivisesti kytketyssä plasmassa
2017
Tässä tutkielmassa tarkasteltiin hiilen matriisivaikutuksia induktiivisesti kytkettyä plasmaa (ICP) hyödyntävissä analyysimenetelmissä. Kirjallisessa osassa on tarkasteltu erilaisia kiinteiden näytteiden esikäsittelymenetelmiä kiinnittäen huomiota jäännöshiilimääriin. Lisäksi läpi käydään ICP-tekniikoiden teoriaa, laitteistoa ja häiriöitä, painotuksen ollessa hiilen aiheuttamissa ongelmatekijöissä. Kokeellisessa osassa tutkittiin onko hiilellä merkittäviä vaikutuksia muovien hivenaineille (As, Cd, Cr, Pb, Sb, Sn, Zn, S) sellaisissa pitoisuuksissa, joita jäännöshiilipitoisuudelta voidaan odottaa kiinteiden näytteiden esikäsittelyn jälkeen. Jäljitellen sertifioituja muovimateriaaleja valmiste…
High-quality superconducting titanium nitride thin film growth using infra-red pulsed laser deposition
2018
Superconducting titanium nitride (TiN) thin films were deposited on magnesium oxide, sapphire and silicon nitride substrates at 700 °C, using a pulsed laser deposition (PLD) technique, where infrared (1064 nm) pulses from a solid-state laser were used for the ablation from a titanium target in a nitrogen atmosphere. Structural studies performed with x-ray diffraction showed the best epitaxial crystallinity for films deposited on MgO. In the best films, superconducting transition temperatures, T C, as high as 4.8 K were observed, higher than in most previous superconducting TiN thin films deposited with reactive sputtering. A room temperature resistivity down to ~17 μΩ cm and residual resist…