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2. Characterization of electrochemical processes in metal-organic batteries by X-ray Raman spectroscopyAva Rajh, Iztok Arčon, Klemen Bučar, Matjaž Žitnik, Marko Petric, Alen Vižintin, Jan Bitenc, Urban Košir, Robert Dominko, Hlynur Gretarsson, Martin Sundermann, Matjaž Kavčič, 2022, izvirni znanstveni članek Opis: X-ray Raman spectroscopy (XRS) is an emerging
spectroscopic technique that utilizes inelastic scattering of hard Xrays
to study X-ray absorption edges of low Z elements in bulk
material. It was used to identify and quantify the amount of
carbonyl bonds in a cathode sample, in order to track the redox
reaction inside metal−organic batteries during the charge/
discharge cycle. XRS was used to record the oxygen K-edge
absorption spectra of organic polymer cathodes from different
multivalent metal−organic batteries. The amount of carbonyl bond
in each sample was determined by modeling the oxygen K-edge
XRS spectra with the linear combination of two reference compounds that mimicked the fully charged and the fully discharged
phases of the battery. To interpret experimental XRS spectra, theoretical calculations of oxygen K-edge absorption spectra based on
density functional theory were performed. Overall, a good agreement between the amount of carbonyl bond present during different
stages of battery cycle, calculated from linear combination of standards, and the amount obtained from electrochemical
characterization based on measured capacity was achieved. The electrochemical mechanism in all studied batteries was confirmed to
be a reduction of double carbonyl bond and the intermediate anion was identified with the help of theoretical calculations. X-ray
Raman spectroscopy of the oxygen K-edge was shown to be a viable characterization technique for accurate tracking of the redox
reaction inside metal−organic batteries. Ključne besede: X-ray Raman spectroscopy, meta-organic batteries, oxygen K-edge XANES, electrochemical processes Objavljeno v RUNG: 24.03.2022; Ogledov: 1747; Prenosov: 20 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
3. Barve v filmuAlen Dolšak, 2021, diplomsko delo Opis: V pričujočem diplomskem delu sem predstavil potek celotnega postopka barvne obdelave filma, orodja, ki jih uporabljamo pri tem postopku, ter osnovno znanje, ki ga potrebujemo za barvno obdelavo filma.
Poleg tega sem se dotaknil teorije barve ter razumevanja, kako barve delujejo kot pripovedovalno sredstvo na podzavestno (čustveno) raven.
Opis procesov je razdeljen na dva dela, in sicer na opis procesa, ki izvaja večina študentov, ter opis procesa, ki sem ga sam uporabljal zaradi posebnih ciljev, ki sem si jih zadal za svoj praktični del diplomske naloge.
V zadnjem delu diplomske naloge sem opisal cilje svojega praktičnega dela, filma z naslovom Preden odideš, kako sem jih dosegel ter težave, na katere sem naletel med montažo filma. Ključne besede: barvna korekcija, barvni prostor, LUT, logaritmični zapis, HDR, video montaža Objavljeno v RUNG: 20.12.2021; Ogledov: 2168; Prenosov: 83 Celotno besedilo (1,58 MB) Gradivo ima več datotek! Več... |
4. The influence of selected indigenous yeasts on Pinot Noir wine colour propertiesJelena Topić, Lorena Butinar, Guillaume Antalick, Melita Sternad Lemut, Mitja Martelanc, Alen Albreht, Dorota Korte, Branka Mozetič Vodopivec, 2021, izvirni znanstveni članek Ključne besede: Pinot Noir, wine colour, yeasts, non-Saccharomyces, sensory Objavljeno v RUNG: 07.07.2021; Ogledov: 2162; Prenosov: 0 Gradivo ima več datotek! Več... |
5. Spectroscopic insights into the electrochemical mechanism of rechargeable calcium/sulfur batteriesAntonio Scafuri, Romain Berthelot, Klemen Pirnat, Alen Vižintin, Jan Bitenc, Giuliana Aquilanti, Dominique Foix, Rémi Dedryvère, Iztok Arčon, Robert Dominko, Lorenzo Stievano, 13, izvirni znanstveni članek Opis: Calcium batteries represent a promising alternative to lithium metal systems. The combination of the low redox potential and low cost and the energy-dense calcium anode (2073 mAh/cm3, similar to 2044 mAh/cm3 for Li) with appropriate low-cost cathode materials such as sulfur could produce a game-changing technology in several fields of applications. In this work, we present the reversible activity of a proof-of-concept Ca/S battery at room temperature, characterized by a surprising medium-term cycling stability with low polarization, promoted by the use of a simple positive electrode made of sulfur supported on an activated carbon cloth scaffold, and a state-of-the-art fluorinated alkoxyborate-based electrolyte. Insights into the electrochemical mechanism governing the chemistry of the Ca/S system were obtained for the first time by combining X-ray photoelectron spectroscopy and X-ray absorption spectroscopy. The mechanism implies the formation of different types of soluble polysulfide species during both charge and discharge at room temperature, and the formation of solid CaS at the end of discharge. The reversible electrochemical activity is proven by the reformation of elemental sulfur at the end of the following charge. These promising results open the way to the comprehension of emerging Ca/S systems, which may represent a valid alternative to Mg/S and Li/S batteries. Ključne besede: Calcium/Sulfur Batteries
EXAFS, XANES Objavljeno v RUNG: 17.10.2020; Ogledov: 2942; Prenosov: 0 Gradivo ima več datotek! Več... |
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7. Synthesis of pyranoanthocyanins from Pinot Noir grape skin extract using fermentation with high pyranoanthocyanin producing yeasts and model wine storage as potential approaches in the production of stable natural food colorantsJelena Topić, Natka Ćurko, Karin Kovačević Ganić, Lorena Butinar, Alen Albreht, Irena Vovk, Dorota Korte, Branka Mozetič Vodopivec, 2020, izvirni znanstveni članek Ključne besede: Pyranoanthocyanins, Anthocyanins, Food colorants, Yeasts, Fermentation Objavljeno v RUNG: 03.04.2020; Ogledov: 3859; Prenosov: 0 Gradivo ima več datotek! Več... |
8. ANALIZA STANJA NAPRAV ZA NANAŠANJE FITOFARMACEVTSKIH SREDSTEV V OBČINAH BRDA IN NOVA GORICAAlen Maligoj, 2020, diplomsko delo Opis: V letu 2018 smo na področju občin Brda in Nova Gorica opravili redni pregled naprav za nanos FFS. Na pršilnikih smo v skladu z zakonodajo preverili tehnično brezhibnost celotne naprave in njenih posameznih sestavnih sklopov. Podatke smo primerjali s podatki iz rednega pregleda naprav za nanos fitofarmacevtskih sredstev na istem področju iz leta 2014 ter s podatki iz literature in ankete, opravljene na terenu. V letu 2018 smo analizirali 992 pršilnikov, leta 2014 pa 263 pršilnikov. Povprečna starost pršilnikov v Brdih je 27 let, v Novi Gorici pa so eno leto mlajši. Ugotovili smo, da se je delež neustreznih pršilnikov na področju obeh občin v letu 2018 zmanjšal. V Brdih je na prvem mestu napak zamašena šoba s 23,7 % deležem; sledi poškodovan ali neustrezen manometer z 20,3 % deležem. V Novi Gorici je na prvem mestu napak poškodovan ali neustrezen manometer s 26,7 % deležem in za njim zamašena šoba z 19,8 % deležem. Po vsakem škropljenju očisti pršilnike v Brdih 60,26 % od vseh anketirancev, na področju Nove Gorice pa 52,05 %. Analiza stanja pršilnikov je pokazala, da sta poglavitna vzroka tehničnih napak nečistoča in neustrezno vzdrževanje naprav. Ključne besede: pršilniki, redni pregled, tehnične napake, vzdrževanje. Objavljeno v RUNG: 02.02.2020; Ogledov: 3715; Prenosov: 116 Celotno besedilo (1,25 MB) |
9. The impact of Saccharomyces and non-Saccharomyces yeasts on wine colour: a laboratory study of vinylphenolic pyranoanthocyanin formation and anthocyanin cell wall adsorptionJelena Topić, Lorena Butinar, Alen Albreht, Irena Vovk, Dorota Korte, Branka Mozetič Vodopivec, 2020, izvirni znanstveni članek Ključne besede: Non-Saccharomyces yeast, Hydroxycinnamate decarboxylase activity, Sequential fermentation, Vinylphenolic pyranoanthocyanins, Anthocyanin adsorption Objavljeno v RUNG: 23.01.2020; Ogledov: 3208; Prenosov: 0 Gradivo ima več datotek! Več... |
10. Role of Cu current collector on electrochemical mechanism of Mg–S batteryAna Robba, Maja Mežnar, Alen Vižintin, Jan Bitenc, Jernej Bobnar, Iztok Arčon, Anna Randon-Vitanova, Robert Dominko, 2020, izvirni znanstveni članek Opis: Development of magnesium sulfur battery is accompanied with all known difficulties present in Li–S batteries,
however with even more limited choice of electrolytes. In the present work, the influence of current collector on
electrochemical mechanism was investigated in light of different reports where improved behavior was ascribed
to electrolyte. Notable differences in cycling behavior are reported when Al current collector is replaced by Cu
current collector independent of electrolyte. The initial reduction of sulfur follows similar reaction path no mater
of current collector, but formation of MgS can be in competition with formation of CuS in the presence of Cu
cations. With the subsequent cycling cells prepared from cathodes deposited on Cu current collector show
decrease in the voltage and formation of single plateau during cycling. The change corresponds to the
involvement of Cu into the reaction and formation of redox couple Mg/CuS as determined by Cu K-edge XANES
measurements. Corrosion of Cu foil is identified by SEM and serves as a source of Cu cations for the chemical
reaction between Cu and polysulfides. Mg/CuS redox couple shows improved cycling stability, but theoretical
energy density is severely reduced due to substitution of S with CuS as cathode active material. Ključne besede: Magnesium
Sulfur
Rechargeable batteries
Current collector
Copper
Corrosion Objavljeno v RUNG: 16.01.2020; Ogledov: 3032; Prenosov: 0 Gradivo ima več datotek! Več... |