Search results for "EPMA"
showing 4 items of 4 documents
Pamatdatu pārvaldīšana lielapjoma datu sistēmās bāzētās Oracle Hyperion platformā
2017
Maģistra darba pētījumam ir izvēlēta kādas Zviedrijas bankas Hyperion Planning lietotne, kura tiek izmantota darījumu mērķu uzstādīšanai. Autores galvenais mērķis bija uzlabot bankas datu kvalitāti un pamatdatu pārvaldīšanas procesus, lai izvairītos no problēmām saistītām ar datu migrāciju starp lietotnēm, kļūdainām datu kalkulācijām un neprecīzām atskaitēm. Galvenais risinājums tika izstrādāts, izmantojot Oracle DRM pamatdatu pārvaldīšanas rīku, ar kura palīdzību pamatdatu apstrāde tika automatizēta, tādējādi samazinot cilvēciskā faktora risku. Rezultātā risinājums tika ieviests bankas sistēmā, kas tai deva ievērojamus uzlabojumus: tika nodrošināta papildus kvalitātes kontrole un versijpār…
High spatial resolution analysis of the iron oxidation state in silicate glasses using the electron probe
2018
The iron oxidation state in silicate melts is important for understanding their physical properties, although it is most often used to estimate the oxygen fugacity of magmatic systems. Often high spatial resolution analyses are required, yet the available techniques, such as μrXANES and μMössbauer, require synchrotron access. The flank method is an electron probe technique with the potential to measure Fe oxidation state at high spatial resolution but requires careful method development to reduce errors related to sample damage, especially for hydrous glasses. The intensity ratios derived from measurements on the flanks of FeLα and FeLβ X-rays (FeLβf/FeLαf) over a time interval (time-depend…
Chlorine as a Discriminant Element to Establish the Provenance of Central Mediterranean Obsidians
2020
Abstract Chlorine is a minor element present in obsidians in quantities greater than in average igneous rocks. The chlorine concentration in obsidians is generally low, of the order of tenths of wt %, but it exhibits an appreciable differentiation among geological sources. Despite these characteristics, chlorine has rarely been taken into consideration as a possible indicator of obsidian provenance and it does not appear in the chemical analytical tables accompanying the geochemical characterisation of obsidian samples. In this work, after an overview of chlorine geochemistry and cycle, we present thirty-one new electron microprobe (EPMA) analyses, including Cl, of geologic obsidians sample…
Diagenetic stability of non-traditional stable isotope systems (Ca, Sr, Mg, Zn) in teeth – An in-vitro alteration experiment of biogenic apatite in i…
2021
Stable isotope ratios and trace element concentrations of fossil bones and teeth are important geochemical proxies for the reconstruction of diet and past environment in archaeology and palaeontology. However, since diagenesis can significantly alter primary diet-related isotope signatures and elemental compositions, it is important to understand and quantify alteration processes. Here, we present the results of in-vitro alteration experiments of dental tissues from a modern African elephant molar reacted in aqueous solutions at 30 °C and 90 °C for 4 to 63 days. Dental cubes with ≈ 3 mm edge length, comprising both enamel and dentin, were placed into 2 mL of acidic aqueous sol…