Publications by Year: 2011

Lagoyannis A, Andrianis M, Axiotis M, Mertzimekis TJ, Ashley SF, Konstantinopoulos T, Provatas G, Huszank R, Harissopulos S. The installation of PAPAP at the Tandem Laboratory of the Institute of Nuclear Physics NCSR ``Demokritos''. In: HNPS2011. Hellenic Nuclear Physics Society; 2011.
Godelitsas A, Nastos P, Mertzimekis TJ, Toli K, Douvalis A, Simon R. Characterization of Saharan dust from red rain precipitated over Athens, Greece. In: Goldschmidt Conference, 11-14 August 2011, Prague, Chech Republic. Vol. 924. ; 2011. pp. 75.
for the Collaboration TMGANILJE513. The ground state g factor of $^{44}$Cl: a probe for the reduced gaps at Z=16 and N=28. In: Frontiers In Nuclear Structure and Astrophysics 3: 22-27 Aug 2010, Rodos, Greece. Vol. 1377. ; 2011. pp. 395.
Godelitsas A, Nastos P, Mertzimekis TJ, Toli K, Simon R, Göttlicher J. A microscopic and Synchrotron-based characterization of urban particulate matter (PM10–PM2.5 and PM2.5) from Athens atmosphere, Greece. Nucl. Instrum. Meth. Phys. Res. B. 2011;269:3077 – 3081.Abstract
Urban particulate matter (PM10–PM2.5 and PM2.5) from Athens (Greece) atmosphere, primarily investigated by SEM-EDS, was further studied in the \{FLUO\} and SUL-X beamlines of \{ANKA\} Synchrotron facility (KIT, Germany). The \{SR\} μ-XRF study showed both geological (e.g. CaTi, CaK and CaSrKRb) and anthropogenic particles exhibiting heavy metal combinations such as FeCo, FeCoCuV and ZnV. It was also revealed that very hazardous metalloids and heavy metals, namely As and Pb, are concentrated in isolated respirable (PM2.5) microparticles. It was attempted to investigate the oxidation state of As by means of μ-XANES. The As K-edge \{XANES\} spectrum of the sample shows a main peak at about 11.874 keV which matches adequately with the As(V) reference spectrum but part of the As seems to have a lower oxidation state (most probably As(III)). This is the first non-bulk study with regard to the partitioning and solid-state speciation of hazardous chemical elements in urban atmospheric microparticles from greater Athens area, rated as an alpha-world city with a population of ca. 4 million people.
Gamaletsos P, Godelitsas A, Mertzimekis TJ, Göttlicher J, Steininger R, Xanthos S, Berndt J, Klemme S, Kuzmin A, Bárdossy G. Thorium partitioning in Greek industrial bauxite investigated by synchrotron radiation and laser-ablation techniques. Nucl. Instrum. Meth. Phys. Res. B. 2011;269:3067 – 3073.Abstract
Typical red–brown (Fe-rich) and high-quality white–grey (Fe-depleted) bauxite samples from active mines of the Parnassos-Ghiona area, central Greece, were investigated. According to \{XRF\} and ICP-MS analyses their actinide content, and particularly of Th, is relatively increased. Fe-depleted samples contain up to 62.75 ppm Th corresponding to 220 Bq/kg due to 228Ac (232Th-series), whereas Fe-rich samples are less Th-radioactive (up to 58.25 ppm Th, 180 Bq/kg due to 228Ac). Powder-XRD patterns showed that Th-enriched (Fe-depleted) bauxite consists mostly of diaspore (AlOOH polymorph), anatase and rutile (TiO2 polymorphs). SEM-EDS indicated the presence of Ti–Fe–containing phases (e.g. ilmenite, FeTiO3), chromite (Cr-spinel) and besides LREE-minerals (mostly bastnäsite/parisite-group) and zircon (ZrSiO4) hosting a part of the bulk Th. The presence of Th in diaspore and in Ti-containing phases (not detected by SEM-EDS as in the case of REE-minerals and zircon) was investigated, into distinct pisoliths of Fe-depleted bauxite, using μ-XRF and μ-XAFS in the SUL-X beamline of the \{ANKA\} Synchrotron facility (KIT, Germany). \{XAFS\} spectra of Th salts and Th-containing reference materials were obtained as well. Accordingly it was revealed, for the first time in the literature, that Ti-phases, and particularly anatase, host significant amounts of Th. This novel conclusion was complementary supported by LA-ICP-MS analyses indicated an average of 73 ppm Th in anatase grains together with abundant Nb (3356 ppm), Ta (247 ppm) and U (33 ppm). The Th LIII-edge \{XAFS\} spectra as compared to reference materials, give also evidence that Th4+ may not replace Ti4+ in distorted [TiO6] fundamental octahedral units of anatase and ilmenite lattice (CN = 6). The occupation of either extraframework sites of higher coordination (CN = 6.9 or even CN = 7.4), according to \{EXAFS\} signals evaluation, or of defected/vacant (**) sites is more probable. This is likely explained by the difficulty of Th4+ to replace directly Ti4+ in [6]-coordinated (octahedral) sites due to the large difference in the relevant ionic radii (0.940 and 0.605 Å respectively).