1. Speakers' errors in the use of the 'count form' in Bulgarian numeral phrases : possible sources of the distance effectPenka Stateva, Julie Franck, Arthur Stepanov, 2023, original scientific article Abstract: In Bulgarian, numerals such as pet ('five') assign a special 'count form' feature to the noun: this assignment takes place across any number of intervening modifier phrases, thus forming a long-distance syntactic dependency. In colloquial speech, speakers often erroneously substitute the count form for regular plurals. Previous corpus and psycholinguistic research established that the ratio of such errors correlates with the distance between numeral and the noun in terms of the number of intervening items. In this note we briefly review this line of inquiry and outline two possible explanations for the distance effect: (i) the cost of maintaining and/or retrieving the numeral in the working memory, and (ii) cumulative activation of the plural markings on the intervening adjectivals. Keywords: numeral, syntactic dependency, language processing, working memory, activation, Bulgarian Published in RUNG: 12.02.2024; Views: 1429; Downloads: 5 Link to file This document has many files! More... |
2. CO[sub]2 activation over nanoshaped CeO[sub]2 decorated with nickel for low-temperature methane dry reformingKristijan Lorber, Janez Zavašnik, Iztok Arčon, Matej Huš, Janvit Teržan, Blaž Likozar, Petar Djinović, original scientific article Abstract: Dry reforming of methane (DRM) is a promising way to
convert methane and carbon dioxide into H2 and CO (syngas). CeO2
nanorods, nanocubes, and nanospheres were decorated with 1−4 wt % Ni.
The materials were structurally characterized using TEM and in situ
XANES/EXAFS. The CO2 activation was analyzed by DFT and
temperature-programmed techniques combined with MS-DRIFTS. Synthesized CeO2 morphologies expose {111} and {100} terminating facets,
varying the strength of the CO2 interaction and redox properties, which
influence the CO2 activation. Temperature-programmed CO2 DRIFTS
analysis revealed that under hydrogen-lean conditions mono- and bidentate
carbonates are hydrogenated to formate intermediates, which decompose
to H2O and CO. In excess hydrogen, methane is the preferred reaction
product. The CeO2 cubes favor the formation of a polydentate carbonate
species, which is an inert spectator during DRM at 500 °C. Polydentate covers a considerable fraction of ceria’s surface, resulting in
less-abundant surface sites for CO2 dissociation Keywords: surface carbonates, in situ characterization, Ni XANES, Ni EXAFS, spectator species, CeO2 nanoshapes, CO2 activation Published in RUNG: 13.07.2022; Views: 2549; Downloads: 0 This document has many files! More... |
3. Effect of Na, Cs and Ca on propylene epoxidation selectivity over CuOx/SiO2 catalysts studied by catalytic tests, in-situ XAS and DFTJanvit Teržan, Matej Huš, Iztok Arčon, Blaž Likozar, Petar Djinović, 2020, original scientific article Abstract: This research focuses on epoxidation of propylene over pristine, Na, Ca and Cs modified
CuOx/SiO2 catalysts using O2. The selectivity of the reaction is analyzed using a combination
of catalytic tests, in-situ XAS and DFT calculations. The initially present subnanometer CuO
clusters are present in all catalysts which re-disperse/flatten during reaction. During catalytic
reaction, the Cu1+ becomes the predominant oxidation state. There is no correlation between
propylene oxide (PO) selectivity and copper oxidation state. DFT analysis of the propylene
reaction pathway revealed that Na, Cs, and Ca addition decreases the bonding strength of
propylene to CuO and decreases the O2 activation barrier, while simultaneously increase the
exothermicity of O2 dissociation. The Na induced Cu-O bond modification decreases the
activation barrier from 0.87 to 0.71 eV for the oxametallacycle (OMC) ring closure (first step
in the reaction pathway favoring selectivity towards PO) compared to pristine 5Cu catalyst.
At the same time, we observed an increase (from 0.45 to 0.72 eV) of the barrier for the
abstraction of allylic hydrogen. The opposite effect is achieved by Ca addition: the activation
barrier for OMC ring closure increases to 1.08 eV and that for allylic hydrogen stripping
decreases to 0.16 eV. Keywords: Alkali modification, propylene epoxidation, reaction mechanism, copper oxide, activation barrier. Published in RUNG: 05.06.2020; Views: 3711; Downloads: 0 This document has many files! More... |
4. The mechanism of Li2S activation in lithium-sulfur batteries: Can we avoid the polysulfide formation?Alen Vižintin, Laurent Chabanne, Elena Tchernychova, Iztok Arčon, Lorenzo Stievano, Giuliana Aquilanti, Markus Antonietti, Tim-Patric Fellinger, Robert Dominko, 2017, original scientific article Abstract: Electrochemical reactions in the LieS batteries are considered as a multistep reaction process with at least
2e3 equilibrium states. Here we report a possibility of having a conversion of Li2S into sulfur without
detectible formation of polysulfides. That was confirmed by using a novel material system consisting of
carbon coated Li2S particles prepared by carbothermal reduction of Li2SO4. Two independent in operando
measurements showed direct oxidation of Li2S into sulfur for this system, with almost negligible formation
of polysulfides at potentials above 2.5 V vs. Li/Liþ. Our results link the diversity of first charge profiles in the
literature to the Li2S oxidation mechanism and show the importance of ionic wiring within the material.
Furthermore, we demonstrate that the Li2S oxidation mechanism depends on the relative amount of
soluble sulfur in the electrolyte. By controlling the type and the amount of electrolyte within the encapsulating
carbon shell, it is thereby possible to control the reaction mechanism of Li2S activation. Keywords: Lithium-sulfur batteries
Li2S active material
XAS
UV/Vis spectroscopy
Li2S activation Published in RUNG: 03.03.2017; Views: 6252; Downloads: 0 This document has many files! More... |