61. Saturation magnetisation as an indicator of the disintegration of barium hexaferrite nanoplatelets during the surface functionalisationDarja Lisjak, Iztok Arčon, Matic Poberžnik, Gabriela Herrero‑Saboya, Ali Tufani, Andraž Mavrič, Matjaž Valant, Patricija Hribar, Alenka Mertelj, Darko Makovec, Layla Martin‑Samos, 2023, original scientific article Published in DiRROS: 02.02.2023; Views: 667; Downloads: 349
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62. Stanje slovenskih gozdov : poročilo o rezultatih nacionalne gozdne inventure 2021Mitja Skudnik, Jernej Jevšenak, Luka Krajnc, Gal Kušar, Anže Martin Pintar, 2023, treatise, preliminary study, study Keywords: monitoring, nacionalna gozdna inventura, odmrla lesna biomasa, temeljnica, površina gozda, lesna zaloga, vzorčne ploskve, poročila
Published in DiRROS: 17.01.2023; Views: 473; Downloads: 0 |
63. Pridobivanje podatkov o spremembah zalog ogljika v živi in odmrli biomasi v gozdovih : vmesno poročilo (Mejnik 3) za: Javno naročilo: 430-204/2021/19Mitja Skudnik, Polona Hafner, Andrej Grah, Jernej Jevšenak, Gal Kušar, Luka Krajnc, Tom Levanič, Boštjan Mali, Anže Martin Pintar, Janez Zafran, 2022, treatise, preliminary study, study Keywords: odmrla lesna biomasa, temeljnica, površina gozda, lesna zaloga, vzorčne ploskve, starost gozdov, kakovost stoječih dreves
Published in DiRROS: 17.01.2023; Views: 526; Downloads: 0 |
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65. Characterization of fresh PM deposits on calcareous stone surfaces : seasonality, source apportionment and soiling potentialMonika Ogrizek, Asta Gregorič, Matic Ivančič, Daniele Contini, Urša Skube, Kristijan Vidović, Marjan Bele, Martin Šala, Marta Klanjšek Gunde, Martin Rigler, Eva Menart, Ana Kroflič, 2023, original scientific article Published in DiRROS: 24.11.2022; Views: 588; Downloads: 408
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68. Preliminary chemical and mineralogical characterization of tailings from base metal sulfide deposits in Serbia and North MacedoniaTimotheus Martin Christoph Steiner, Viktor Bertrandsson Erlandsson, Robert Šajn, Frank Melcher, 2022, original scientific article Abstract: Tailings of old mines often contain metals, which were not of economic interest or could not be recovered with the existing technology at the time of active mining. This is especially true for metals that often occur as by-products in Cu-Pb-Zn-(Ag-Au) ores as Sb, Mo, Ge, and In. A fundamental characterization of some tailings is presented in terms of their mineralogy and content of valuable metals which could be extracted to finance a possible remediation and improve the supply of the EU with critical metals. Tailings from active and abandoned mines in Serbia (Bor, porphyry Cu/Au; Krivelj, porphyry Cu/Au; Blagodat, hydrothermal Pb-Zn; Lece, epithermal Au; Rudnik, hydrothermal/skarn Pb-Zn) and North Macedonia (Sasa, Pb-Zn; Probištip, Pb-Zn; Bučim, porphyry Cu; Lojane, fault-bound vein-type low-temperature As, Sb, Cr at the contact of rhyolite and serpentinite) were studied. Analysis for major and trace elements used a multi-method approach (lithium borate fusion and ICP-MS/OES analysis, gravimetric analysis, instrumental neutron activation analysis, total digestion ICP-OES, infrared spectroscopy) with mineral identification by scanning electron microscopy. Concentrations of the major commodity elements (Cu, Pb, Zn, Au, Ag) varies within several orders of magnitude depending on mineralogy and ore type. Critical metals (Co, Ga, Ge, Sb) contents are low with some exceptions. Some tailings contain moderate to elevated potentially toxic element levels (As, Cd, Pb, Tl). For the sample from Probištip which yielded the highest valuable metal concentrations (>5000 ppm Pb, 4020 ppm Zn), a heavy mineral concentrate of the sand size fraction (0.06 mm to 0.5 mm) was produced and analyzed by SEM and LA-ICP-MS for additional rare phases and trace elements. In all tailings studied, additional milling would be needed to separate ore from gangue minerals. Increasing metal prices might facilitate feasibility studies for some of the localities in the future, despite the limited quantitative information about the characterized tailings.
Keywords: rudniški odpadki, kemija, mineralogija, rudna nahajališča, sulfidi
Published in DiRROS: 22.11.2022; Views: 534; Downloads: 157
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69. Controlled growth of ZnO nanoparticles using ethanolic root extract of Japanese knotweed : photocatalytic and antimicrobial propertiesMiha Ravbar, Ajda Kunčič, Lev Matoh, Sonja Smole Možina, Martin Šala, Andraž Šuligoj, 2022, original scientific article Abstract: Synthesis of zinc oxide (ZnO) nanoparticles (NPs) was mediated by plant extracts to assist in the reduction of zinc atoms during the synthesis and act as a capping agent during annealing.The preparation used ethanolic extracts from the roots of Japanese knotweed (Fallopia japonica). Two major outcomes could be made. (i)A synergistic effect of multiple polyphenolic components in the extract is needed to achieve the capping effect of crystallite growth during thermal annealing at 450 °C characterized by an exponential growth factor (n) of 4.4 compared to n = 3 for bare ZnO. (ii) Synergism between the ZnO NPs and plant extracts resulted in superior antimicrobial activity against both Gram-positive bacteria, e.g., Staphylococcus aureus, and Gram-negative bacteria, e.g., Escherichia coli and Campylobacter jejuni. The materials were also tested for their antimicrobial activity against S. aureus under ultraviolet (UV) illumination. Also here, the photocatalyst prepared with plant extracts was found to be superior. The residues of the plant extract molecules on the surface of the catalyst were identified as the main cause of the observed differences, as proved by thermal gravimetry. Such a preparation using ethanolic extract of Fallopia japonica could serve as a more controlled synthesis of ZnO and potentially other metal oxides, with low environmental impact and high abundance in nature.
Published in DiRROS: 21.11.2022; Views: 412; Downloads: 195
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70. Characterization of atmospheric deposition as the only mineral matter input to ombrotrophic bogValentina Pezdir, Martin Gaberšek, Mateja Gosar, 2022, original scientific article Abstract: Ombrotrophic peatlands contain a very small percentage of mineral matter that they receive exclusively from atmospheric deposition. Mineral matter deposited on the Šijec bog was characterized using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). We collected solid atmospheric deposition from snow, rainwater, and using passive samplers. Samples were collected at average atmospheric conditions and after two dust events. Size, morphology, and chemical composition of individual particles were determined. We distinguished four main particle groups: silicates, carbonates, organic particles, and Fe-oxyhydroxides. Silicate particles are further divided into quartz and aluminosilicates. Proportions of these groups vary between samples and between sample types. In all samples, silicate particles predominate. Samples affected by dust events are richer in solid particles. This is well observed in passive deposition samples. Carbonates and organic particles represent smaller fractions and are probably of local origin. Iron-oxyhydroxides make up a smaller, but significant part of particles and are, according to their shape and chemical composition, of both geogenic and anthropogenic origin. Estimated quantity and percentage of main groups vary throughout the year and are highly dependent on weather conditions. Dust events represent periods of increased deposition and contribute significantly to mineral matter input to peatlands.
Keywords: atmospheric deposition, SEM/EDS, mineral matter, peatland
Published in DiRROS: 08.09.2022; Views: 542; Downloads: 250
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