11. IZVOZ VIN KLETI BRDA, Z. O. O., V ZADNJIH DVAJSETIH LETIHTereza Valentinčič, 2022, diplomsko delo Opis: Izvoz je postal zelo pomemben vir prihodkov in nič drugače ni tudi za vino. Slovenska vina so vedno bolj prepoznavna na vinskem zemljevidu in vedno več držav si želi uvažati slovenska vina, zato ni čudno, da so slovenski vinarji na tujih trgih vedno bolj uspešni. Največja izvoznica slovenskih vin je Klet Brda, z. o. o, ki izvaža v že kar 26 držav po svetu. V diplomskem delu se posvetimo izvozu Kleti Brda in izpostavimo tri največje države, v katere izvaža in so si med seboj različne. To so Združene države Amerike, Kitajska in Velika Britanija. Kaj je pomembno, da je izvoz uspešen in kakšna komunikacija je potrebna, da je prodaja uspešna? Skozi intervjuje, ki smo jih opravili z zaposlenimi v Kleti Brda, smo spoznali potek in delo, ki smo ga v diplomskem delu tudi opisali. Izpostavili smo razlike med državami in kakšne metode se uporabljajo, da je prodaja na določenem trgu uspešna. Skozi delo spoznamo, kako poteka izvoz v kleti in kako se je v zadnjih dvajsetih letih spreminjal.
Ključne besede: izvoz, Klet Brda, z. o. o, Združene države Amerike, Kitajska, Velika Britanija
Objavljeno v RUNG: 04.11.2022; Ogledov: 1311; Prenosov: 26
 Celotno besedilo (890,46 KB) |
12. Monitoring chemical processes in (photo)catalysts and energy storage materials by operando X-ray absorption spectroscopyIztok Arčon, 2022, objavljeni povzetek znanstvenega prispevka na konferenci (vabljeno predavanje) Opis: X-ray absorption spectroscopy (XAS) is a powerful tool for characterisation of local structure and chemical state of selected elements in different new functional materials and biological or environmental samples. The XAS spectroscopy is based on extremely bright synchrotron radiation X-rays sources, which allow precise characterisation of bulk, nanostructured or highly diluted samples. The rapid development of extremely bright synchrotron sources of X-ray and ultraviolet light in recent years has opened new possibilities for research of matter at the atomic or molecular level, indispensable in the development of new functional nanostructured materials with desired properties. The talk will present the possibilities offered by X-ray absorption spectroscopy with synchrotron light for ex-situ or operando characterization of various functional porous and other nanomaterials, before, after and during their operation [1,2,3,4]. New generation of synchrotron light sources also opened the possibility of combining X-ray absorption with high-resolution emission [5] and inelastic scattering spectroscopy [6], and microscopy with sub-micron resolution [7]. Examples of operando XANES and EXAFS analysis to track changes in the valence states and local structures of selected elements in different energy storage materials and in various (photo)catalysts, during chemical reactions under controlled reaction conditions, will be presented, which provided insight into the dynamic functional properties and reaction mechanisms of these materials. Access to SR facilities of Petra III (beamlines P65, P64 and P01), ESRF (beamlines BM23, ID21, ID26) and Elettra (beamlines XAFS, XRF), for the presented research is kindly acknowledged.
Ključne besede: X-ray absorption spectroscopy, operando XANES, EXAFS, catalysts, batteries
Objavljeno v RUNG: 07.10.2022; Ogledov: 1067; Prenosov: 0
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13. Photocatalytic sol-gel/P25 TiO [sub] 2 coatings for water treatment : degradation of 7 selected pharmaceuticals (CO3:IL02)Lev Matoh, Boštjan Žener, Marin Kovačić, Hrvoje Kušić, Iztok Arčon, Meta Levstek, Urška Lavrenčič Štangar, 2022, izvirni znanstveni članek Opis: The effect of different water matrices on the photocatalytic degradation of dissolved pharmaceuticals was
explored. The focus was on the degradation efficiencies in wastewater effluent from a bioreactor and water
effluent from a central wastewater treatment plant and comparing the results with degradation in deionized H2O.
The compounds tested included: oxytetracycline, marbofloxacin, ibuprofen, diclofenac, phenytoin, ciprofloxacin,
sulfamethoxazole. For the experiments performed in this study, a compact packed-bed photocatalytic reactor was
used in which the hybrid TiO2 photocatalyst (sol-gel/P25) was deposited on ~3 mm glass beads. As expected, the
reactions proceed more slowly in wastewater than in deionized water, yet it is shown that removal of the
compounds from the water is still possible even when other organic molecules are present. Total organic carbon
measurements have shown that complete mineralization takes place albeit at slower rates than the initial
degradation of parent compounds. The results show that an acidic pH can increase the reaction rates and the
adsorption on the photocatalyst surface. Analyses of the degradation intermediates were performed using tandem
liquid chromatography triple-quadrupole mass spectrometry system. Additionally, X-ray absorption spectroscopy
was applied to get insight into the local structure of the photocatalyst before and after use. Understanding the
effects that different wastewater compositions have on photocatalytic reactions will help to refine the potential
applications of the technology.
Ključne besede: titanium dioxide, sol-gel processes, functionla applications, water treatment
Objavljeno v RUNG: 30.09.2022; Ogledov: 1246; Prenosov: 0
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14. Correlation between FeCl2 electrolyte conductivity and electrolysis efficiencyUroš Luin, Matjaž Valant, Iztok Arčon, 2022, objavljeni povzetek znanstvenega prispevka na konferenci Opis: The electrolysis efficiency is an important aspect of the Power-to-Solid energy storage technology (EST) based
on the iron chloride electrochemical cycle [1]. This cycle employs an aqueous FeCl2 catholyte solution for the
electro-reduction of iron. The metal iron deposits on the cathode. The energy is stored as a difference in the
redox potential of iron species. Hydrogen, as an energy carrier, is released on demand over a fully controlled
hydrogen evolution reaction between metallic Fe0 and HCl (aq) [1]. Due to these characteristics, the cycle is
suitable for long-term high-capacity and high-power energy storage. In a previous work [2] we revealed that
the electrolyte conductivity linearly increases with temperature. Contrary, the correlation between the
electrolyte concentration and efficiency is not so straightforward. Unexpectedly small efficiency variations were
found between 1 and 2.5 mol dm-3 FeCl2 (aq) followed by an abrupt efficiency drop at higher concentrations.
To explain the behavior of the observed trends and elucidate the role of FeCl2 (aq) complex ionic species we
performed in situ X-ray absorption studies. We made a dedicated experimental setup, consisting of a tubular
oven and PMMA liquid absorption cell, and performed the measurements at the DESY synchrotron P65
beamline. The XAS investigation covered XANES and EXAFS analyses of FeCl2 (aq) at different
concentrations (1 - 4 molL-1) and temperatures (25 - 80 °C). We found that at low temperature and low FeCl2
concentration the octahedral first coordination sphere around Fe is occupied by one Cl ion at a distance of 2.33
(±0.02) Å and five water molecules at a distance of 2.095 (±0.005) Å [3]. The structure of the ionic complex
gradually changes with an increase in temperature and/or concentration. The apical water molecule is
substituted by a chlorine ion to yield a neutral Fe[Cl2(H2O)4]0. The transition from the single charged
Fe[Cl(H2O)5]+ to the neutral Fe[Cl2(H2O)4]0 causes a significant drop in the solution conductivity, which well
correlates with the existing conductivity models [3].
[1] M. Valant, “Procedure for electric energy storage in solid matter. United States Patent and
Trademark Office. Patent No. US20200308715,” Patent No. US20200308715, 2021.
[2] U. Luin and M. Valant, “Electrolysis energy efficiency of highly concentrated FeCl2 solutions
for power-to-solid energy storage technology,” J. Solid State Electrochem., vol. 26, no. 4, pp.
929–938, Apr. 2022, doi: 10.1007/S10008-022-05132-Y.
[3] U. Luin, I. Arčon, and M. Valant, “Structure and Population of Complex Ionic Species in
FeCl2 Aqueous Solution by X-ray Absorption Spectroscopy,” Molecules, vol. 27, no. 3, 2022,
doi: 10.3390/molecules27030642.
Ključne besede: Iron chloride electrochemical cycle, Power-to-Solid energy storage, XANES, EXAFS, electrical
conductivity, electrolyte complex ionic species structure and population
Objavljeno v RUNG: 26.09.2022; Ogledov: 1487; Prenosov: 0 (1 glas)
Gradivo ima več datotek! Več... |
15. 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, izvirni znanstveni članek Opis: 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
Ključne besede: surface carbonates, in situ characterization, Ni XANES, Ni EXAFS, spectator species, CeO2 nanoshapes, CO2 activation
Objavljeno v RUNG: 13.07.2022; Ogledov: 1411; Prenosov: 0
Gradivo ima več datotek! Več... |
16. Marketinški načrt za vinoteko (vinotoč in kafe bar) : diplomsko deloDomen Jogan, 2022, diplomsko delo Opis: V diplomskem delu je oblikovan marketinški načrt za Vinoteko Jogan. Pri
marketinškem načrtovanju smo izhajali iz osnovnih vrednot izbranosti in kakovosti, ki
predstavljata osnovo za vse marketinške vsebine in osnovno konkurenčno prednost, s
katero se gostinski lokal pozicionira na trgu ter ustvarja svoj želeni tržni delež. Iz
vrednot izbranosti in kakovosti sta izpeljana vizija in poslanstvo podjetja ter oblikovani
strateški in taktično-operativni cilji za dva segmenta porabnikov, in sicer za stalne
domače obiskovalce in naključne turistične obiskovalce. Med domačimi porabniki
računamo na porabnike, ki cenijo kakovostno gostinsko storitev in izbranost proizvoda,
v segmentu turističnih porabnikov pa predvsem na tiste, ki so za obisk motivirani zaradi
posebnosti okoliščin, da so na potovanju. Izbranost in kakovost proizvoda sta
eksplicirana v tržnem komuniciranju, ki zajema promocijske procese v obliki
oglaševanja in procesa ter okoliščine porabe proizvoda. Bistvenega pomena v
marketinškem spletu so zlasti fizični dokazi, ki morajo podpirati osnovno konkurenčno
prednost s posredovanjem ustreznih impulzov porabniku na ravni vseh njegovih čutov.
Ključne besede: diplomske naloge, gostinstvo, vinoteka, vinotoč, bari, marketinški načrt
Objavljeno v RUNG: 14.06.2022; Ogledov: 1525; Prenosov: 72
Celotno besedilo (839,58 KB) |
17. Monitoring chemical processes on the atomic scale in catalysts by operando X-ray absorption spectrometryIztok Arčon, 2022, objavljeni povzetek znanstvenega prispevka na konferenci (vabljeno predavanje) Opis: X-ray absorption spectroscopy (XAS) is a powerful tool for characterisation of local structure and chemical state of selected elements in different new functional materials and biological or environmental samples. The rapid development of extremely bright synchrotron sources of X-ray and ultraviolet light in recent years has opened new possibilities for research of matter at the atomic or molecular level, indispensable in the development of new functional nanostructured materials with desired properties. The lecture will present the possibilities offered by X-ray absorption spectroscopy with synchrotron light for ex-situ and in-situ or operando characterization of various catalyst materials before, after and during their operation. With the operando XANES and EXAFS methods it is possible to track changes in the valence states and local structures of selected elements in various (photo)catalysts, during chemical reactions under controlled reaction conditions, thus gaining insight into the dynamic functional properties and reaction mechanisms of these materials. New synchrotron light sources also opened the possibility of combining X-ray absorption or emission spectroscopy and microscopy with a resolution of up to a few tens of nanometres, allowing micro-XAS analysis with high spatial resolution.
Ključne besede: XAS, operando XANES, EXAFS, catalysts
Objavljeno v RUNG: 01.06.2022; Ogledov: 1368; Prenosov: 0
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18. Monitoring of chemical processes at the atomic level by X-ray absorption spectrometry using extremely bright synchrotron radiation sourcesIztok Arčon, predavanje na tuji univerzi Opis: X-ray absorption spectroscopy (XAS) is a powerful tool for characterisation of local structure and chemical state of selected elements in different new functional materials and biological or environmental samples. The XAS spectroscopy is based on extremely bright synchrotron radiation X-rays sources, which allow precise characterisation of bulk, nanostructured or highly diluted samples. The rapid development of extremely bright synchrotron sources of X-ray and ultraviolet light in recent years has opened new possibilities for research of matter at the atomic or molecular level, indispensable in the development of new functional nanostructured materials with desired properties. The lecture will present the possibilities offered by X-ray absorption spectroscopy with synchrotron light for ex-situ and in-situ or operando characterization of various functional porous and other nanomaterials before, after and during their operation.
Ključne besede: XAS, operando XANES, EXAFS, functional materials
Objavljeno v RUNG: 01.06.2022; Ogledov: 1303; Prenosov: 0
Gradivo ima več datotek! Več... |
19. Insight into the interdependence of Ni and Al in bifunctional Ni/ZSM-5 catalysts at the nanoscaleHue-Tong Vu, Iztok Arčon, Danilo Oliveira de Souza, Simone Pollastri, Goran Dražić, Janez Volavšek, Gregor Mali, Nataša Zabukovec Logar, Nataša Novak Tušar, 2022, izvirni znanstveni članek Opis: Catalyst design is crucial for improving catalytic activity and product selectivity. In a bifunctional Ni/ZSM-5
zeolite type catalyst, catalytic properties are usually tuned via varying Al and Ni contents. While changes in
acid properties associated with Al sites are usually closely investigated, Ni phases, however, receive
inadequate attention. Herein, we present a systematic structural study of Ni in the Ni/ZSM-5 materials by
using Ni K-edge XANES and EXAFS analyses, complemented by XRD and TEM, to resolve the changes in
the local environment of Ni species induced by the different Al contents of the parent ZSM-5 prepared
by a “green”, template free technique. Ni species in Ni/ZSM-5 exist as NiO crystals (3–50 nm) and as
charge compensating Ni2+ cations. The Ni K-edge XANES and EXAFS results enabled the quantification
of Ni-containing species. At a low Al to Si ratio (nAl/nSi # 0.04), the NiO nanoparticles predominate in
the samples and account for over 65% of Ni phases. However, NiO is outnumbered by Ni2+ cations
attached to the zeolite framework in ZSM-5 with a high Al to Si ratio (nAl/nSi ¼ 0.05) due to a higher
number of framework negative charges imparted by Al. The obtained results show that the number of
highly reducible and active NiO crystals is strongly correlated with the framework Al sites present in
ZSM-5 zeolites, which depend greatly on the synthesis conditions. Therefore, this kind of study is
beneficial for any further investigation of the catalytic activities of Ni/ZSM-5 and other metal-modified
bifunctional catalysts.
Ključne besede: Ni/ZSM-5 catalysts, zeolite, Ni XANES, EXAFS
Objavljeno v RUNG: 11.05.2022; Ogledov: 1565; Prenosov: 43
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