1691. Thresholds to the "Great Unread" : titling practices in eleven ELTeC collectionsRoxana Patraş, Carolin Odebrecht, Ioana Galleron, Rosario Arias, J. Berenike Herrmann, Cvetana Krstev, Katja Mihurko, Dmytro Yesypenko, 2021, original scientific article Keywords: digital humanities, electronic collection, titles
Published in RUNG: 29.10.2021; Views: 1826; Downloads: 67
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1693. Evropska noč raziskovalcev 2021 (ENR2021): ZnAnosT za vsE (ZATE) : Doktorski študij – priložnost na začetku karierne potiAna Toroš, other performed works Abstract: Okrogla miza, organiziran kot spletni dogodek preko videokonferenčnega sistema, je namenjena širokemu krogu mladih, ki jih zanima znanost in bi se radi na svoji karierni poti aktivno vključili v znanstveno raziskovalno delo na različnih področjih znanosti od naravoslovja in tehnike do humanistike ali na izrazito interdisciplinarnih področjih, kot so znanost o okolju, trajnostni razvoj grajenega okolja ali krasoslovje. Na okrogli mizi bodo sodelovali direktorji in direktorice doktorskih programov Fakultete za podiplomski študij(FPŠ) in dekan FPŠ. Na okrogli mizi želimo spodbuditi mlade na začetku svoje karierne poti, da se odločijo za pridobitev raziskovanih izkušenj, ki jih pozneje v poklicni karieri lahko izkoristijo tako v akademskem okolju kot v drugih poklicnih usmeritvah v gospodarstvu ali negospodarskih dejavnostih. Sodelujoči na okrogli mizi bodo predstavili kakšne kompetence, ne le strokovne ampak tudi generične, lahko študentje pridobijo v okviru doktorskega študija in kakšne možnosti se jim s tem odprejo na bodoči karierni poti in pri osebnostnem razvoju. Poslušalci bodo imeli možnost aktivnega vključevanja v razgovor z raziskovalci s postavljanjem vprašanj, na katera bodo člani okrogle mize neposredno odgovarjali.
Keywords: doktorski študij, zaposlitev, humanistika
Published in RUNG: 27.10.2021; Views: 1528; Downloads: 0
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1694. Resolving the dilemma of Fe-N-C catalysts by the selective synthesis of tetrapyrrolic active sites via an imprinting strategyDavide Menga, Jian Liang Low, Yan-Sheng Li, Iztok Arčon, Burak Koyutürk, Friedrich Wagner, Francisco Ruiz-Zepeda, Miran Gaberšček, Beate Paulus, Tim-Patrick Fellinger, 2021, original scientific article Abstract: Combining the abundance and inexpensiveness of
their constituent elements with their atomic dispersion, atomically
dispersed Fe−N−C catalysts represent the most promising
alternative to precious-metal-based materials in proton exchange
membrane (PEM) fuel cells. Due to the high temperatures
involved in their synthesis and the sensitivity of Fe ions toward
carbothermal reduction, current synthetic methods are intrinsically
limited in type and amount of the desired, catalytically active Fe−
N4 sites, and high active site densities have been out of reach
(dilemma of Fe−N−C catalysts). We herein identify a paradigm
change in the synthesis of Fe−N−C catalysts arising from the
developments of other M−N−C single-atom catalysts. Supported
by DFT calculations we propose fundamental principles for the synthesis of M−N−C materials. We further exploit the proposed
principles in a novel synthetic strategy to surpass the dilemma of Fe−N−C catalysts. The selective formation of tetrapyrrolic Zn−N4
sites in a tailor-made Zn−N−C material is utilized as an active-site imprint for the preparation of a corresponding Fe−N−C catalyst.
By successive low- and high-temperature ion exchange reactions, we obtain a phase-pure Fe−N−C catalyst, with a high loading of
atomically dispersed Fe (>3 wt %). Moreover, the catalyst is entirely composed of tetrapyrrolic Fe−N4 sites. The density of
tetrapyrrolic Fe−N4 sites is more than six times as high as for previously reported tetrapyrrolic single-site Fe−N−C fuel cell catalysts
Keywords: Fe-N-C catalysts, selective synthesis, tetrapyrrolic active sites, EXAFS, XANES, single atom, DFT
Published in RUNG: 25.10.2021; Views: 1999; Downloads: 54
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1695. Gravity wave instability structures and turbulence from more than 1.5 years of OH[ast] airglow imager observations in SloveniaRené Sedlak, Patrick Hannawald, Carsten Schmidt, Sabine Wüst, Michael Bittner, Samo Stanič, 2021, original scientific article Abstract: We analyzed 286 nights of data from the OH* airglow imager FAIM 3 (Fast Airglow IMager) acquired at Otlica Observatory, Slovenia, between 26 October 2017 and 6 June 2019. Measurements were performed with a spatial resolution of 24 m per pixel and a temporal resolution of 2.8 s. Multiple turbulence episodes were observed and the energy dissipation rate in the upper mesosphere/lower thermosphere region was estimated from image sequences in 25 cases. Values range around 0.08 and 9.03 W/kg and would lead to an approximated localized maximum heating of 0.03–3.02 K per turbulence event.
Keywords: upper mesosphere, lower thermosphere, remote sensing, gravity waves, turbulence, Bora episodes
Published in RUNG: 25.10.2021; Views: 1877; Downloads: 0
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1699. Orbital selective dynamics in Fe-pnictides triggered by polarized pump pulse excitationsGanesh Adhikary, Tanusree Saha, Primož Rebernik Ribič, Matija Stupar, Barbara Ressel, Jurij Urbančič, Giovanni De Ninno, A. Thamizhavel, Kalobaran Maiti, 2021, original scientific article Abstract: Quantum materials display exotic behaviours related to the interplay between temperature-driven phase transitions. Here, we study the electron dynamics in one such material, CaFe$_2$As$_2$, a parent Fe-based superconductor, employing time and angle-resolved photoemission spectroscopy. CaFe$_2$As$_2$ exhibits concomitant transition to spin density wave state and tetragonal to orthorhombic structure below 170 K. The Fermi surface of this material consists of three hole pockets ($\alpha$, $\beta$ and $\gamma$) around $\Gamma$-point and two electron pockets around $X$-point. The hole pockets have $d_{xy}$, $d_{yz}$ and $d_{zx}$ orbital symmetries. The $\beta$ band constituted by $d_{xz}$/$d_{yz}$ orbitals exhibit a gap across the magnetic phase transition. We discover that polarized pump pulses can induce excitations of electrons of a selected symmetry. More specifically, while $s$-polarized light (polarization vector perpendicular to the $xz$-plane) excites electrons corresponding to all the three hole bands, $p$-polarized light excites electrons essentially from ($\alpha$,$\beta$) bands which are responsible for magnetic order. Interestingly, within the magnetically ordered phase, the excitation due to the $p$-polarized pump pulses occur at a time scale of 50 fs, which is significantly faster than the excitation induced by $s$-polarized light ($\sim$ 200 fs). These results suggest that the relaxation of different ordered phases occurs at different time scales and this method can be used to achieve selective excitations to disentangle complexity in the study of quantum materials.
Keywords: Electronic structure, Pnictides and chalcogenides, Time-resolved spectroscopy
Published in RUNG: 13.10.2021; Views: 1950; Downloads: 6
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