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1.
The fate of ecotoxic hexavalent chromium in the environment
Liviana Leita, Alja Margon, Arnold Pastrello, Iztok Arčon, Marco Contin, Davide Mosetti, Alojz Kodre, 2009, other component parts

Found in: ključnih besedah
Summary of found: ...rentgenska absorpcijska spektroskopija, XANES, ekotoksičnost, okolje, ...
Keywords: rentgenska absorpcijska spektroskopija, XANES, ekotoksičnost, okolje
Published: 15.10.2013; Views: 3118; Downloads: 9
URL Fulltext (0,00 KB)

2.
Structural and magnetic properties of Fe-doped BaTiO [sub] 3 ceramics
I. Mikulska, 2014, doctoral dissertation

Found in: ključnih besedah
Summary of found: ...titanat, kisikova vrzel, Fe rob K EXAFS, XANES, disertacije, ...
Keywords: barijev titanat, kisikova vrzel, Fe rob K EXAFS, XANES, disertacije
Published: 22.01.2015; Views: 2990; Downloads: 229
URL Fulltext (0,00 KB)
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3.
X-ray absorption spectroscopy and related techniques
Iztok Arčon, Alojz Kodre, Jana Padežnik Gomilšek, 2004, original scientific article

Abstract: In the extensive field of X-ray diagnostic techniques, nowadays mostly implemented on synchrotron X-ray sources, the X-ray absorption methods offer a relatively simple tool for structural analysis of materials. The advantage of the methods is the sensitivity to chemical species and the insensitivity to the long-range order. An overview of various detection techniques is given together with the discussion of accuracy of the method with regard to the spatial resolution and the possible contamination by intra-atomic contributions, the multielectron photoexcitations.
Found in: ključnih besedah
Summary of found: ...X-žarki, absorpcija, EXAFS, XANES, ...
Keywords: X-žarki, absorpcija, EXAFS, XANES
Published: 10.07.2015; Views: 2264; Downloads: 14
URL Fulltext (0,00 KB)

4.
Development and characterization of improved materials for antifouling applications
Urška Lavrenčič Štangar, Iztok Arčon, Tihana Čižmar, 2015, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ...sol-gel method, photocatalysis, hybrid materials, Cu K-edge XANES, photocatalytic activity...
Keywords: sol-gel method, photocatalysis, hybrid materials, Cu K-edge XANES, photocatalytic activity
Published: 15.02.2016; Views: 2091; Downloads: 0
.pdf Fulltext (131,22 KB)

5.
X-ray absorption spectroscopy analysis: in situ, operando, in vivo
Iztok Arčon, 2020, published scientific conference contribution abstract (invited lecture)

Abstract: 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. With its two methods (XANES and EXAFS) it enables monitoring changes in valence states and local structures of constituent elements during chemical reactions under controlled reaction conditions, and it offers a possibility of a combination of X-ray spectroscopy and microscopy with sub-micron lateral resolution, crucial for analysis of biological samples on sub-cellular level. In this talk some typical examples of advanced XAS analysis will be presented.
Found in: ključnih besedah
Summary of found: ...highly diluted samples. With its two methods ( XANES and EXAFS) it enables monitoring changes in...
Keywords: X-ray absorption spectroscopy, EXAFS, XANES, in-situ, operando
Published: 17.10.2020; Views: 123; Downloads: 0
.pdf Fulltext (68,21 KB)

6.
Spectroscopic insights into the electrochemical mechanism of rechargeable calcium/sulfur batteries
Giuliana Aquilanti, Jan Bitenc, Romain Berthelot, Antonio Scafuri, Alen Vižintin, Klemen Pirnat, Lorenzo Stievano, Robert Dominko, Iztok Arčon, Rémi Dedryvère, Dominique Foix, 13, original scientific article

Abstract: 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.
Found in: ključnih besedah
Keywords: Calcium/Sulfur Batteries EXAFS, XANES
Published: 17.10.2020; Views: 131; Downloads: 0
.pdf Fulltext (3,74 MB)

7.
Operando (micro) XAFS analysis
Katarina Vogel-Mikuš, Robert Dominko, Iztok Arčon, 2016, published scientific conference contribution abstract (invited lecture)

Abstract: In the talk the principles of XAS methods were presented with practical examples which illustrate the possibilities and advanced approaches for their use in structural analysis of different types of materials. The emphasis will be on to the use of XAS spectroscopy in operando mode and in combination with X-ray microscopy.
Found in: ključnih besedah
Summary of found: ...X-ray absorption spectroscopy, X-ray microscopy, EXAFS, XANES, opearndo mode...
Keywords: X-ray absorption spectroscopy, X-ray microscopy, EXAFS, XANES, opearndo mode
Published: 25.03.2016; Views: 2714; Downloads: 53
.pdf Fulltext (18,40 MB)

8.
Removal of manganese in batch and fluidized bed systems using beads of zeolite a as adsorbent
Bojana Obradovic, Nataša Novak Tušar, Iztok Arčon, Janez Kovač, Mina Jovanovic, Nevenka Rajić, 2016, original scientific article

Abstract: In this study the uptake capacity of Mn(II) ions by zeolite A beads was investigated for different initial Mn concentration (100e400 mg Mn dm^-3) in batch mode at 25e55 C. The obtained adsorption capacity varying from 30 to 50 mg Mn g^-1 demonstrated a high affinity of zeolite A towards Mn(II) present in solutions. Kinetic studies indicated the intra-particle diffusion as the rate limiting step up to 45 C with apparent diffusivities in the range (1.2e2.0) x 10^-13 m2 s^-1 and the activation energy of 21.9 kJ mol^-1, which implies strong interactions between the zeolite A and Mn ions. At 55 C ion-exchange became the rate limiting step. The adsorption isotherms were studied at 25 C showing that the Mn adsorption is the best described by the Langmuir model suggesting a homogenous zeolite surface. XPS analysis of the Mnloaded beads showed that there is no surface accumulation of Mn but an almost uniform Mn distribution inside zeolite A, whereas XANES and EXAFS suggested that the adsorption of Mn(II) was followed by the Mn(II) oxidation and oxide formation. Regeneration of the spent zeolite was examined in 8 adsorption/desorption cycles by a chelating Na2EDTA in a fluidized column. It has been found that zeolite A beads could be reused for at least 4 cycles with satisfactory Mn(II) adsorption efficiencies of about 70%.
Found in: ključnih besedah
Summary of found: ...uniform Mn distribution inside zeolite A, whereas XANES and EXAFS suggested that the adsorption of...
Keywords: Zeolite A Manganese Adsorption kinetics EXAFS/XANES XPS
Published: 01.04.2016; Views: 2355; Downloads: 0
.pdf Fulltext (1,27 MB)

9.
The first example of a mixed valence ternary compound of silver with random distribution of Ag(I) and Ag(II) cations
Iztok Arčon, Zvonko Jagličić, Wojciech Grochala, Zoran Mazej, Evgeny A. Goreshnik, Tomasz Michałowski, Jadwiga Szydłowska, 2015, original scientific article

Found in: ključnih besedah
Summary of found: ...srebrov fluorid, mešana valenca, srebro, XANES, ...
Keywords: srebrov fluorid, mešana valenca, srebro, XANES
Published: 16.06.2016; Views: 1797; Downloads: 94
URL Fulltext (0,00 KB)

10.
XAS and micro-XRF analysis of mono and bi-metallic exopolysaccharide (FePd-EPS) bio-generated by K. oxytoca
Franco Baldi, Katarina Vogel-Mikuš, Michele Gallo, Oreste Piccolo, Stefano Paganelli, Iztok Arčon, 2016, published scientific conference contribution abstract

Abstract: Bacteria Klebsiella oxytoca (DSM 29614) secret a specific exopolysaccharide (EPS) in the presence of Fe(III)-citrate, as sole carbon and energy source, and produces after 7 days an iron gel precipitate (Fe-EPS) [1]. In the presence of palladium or other metal species, the culture of K. oxytoca can produce other mono or bimetal species (Pd-EPS, FePd-EPS) [2]. These bio-materials may be used as green biogenerated catalysts or for other biotechnological purposes. In this work we present the analysis of the morphology and the chemical state of the metals in mono and bi-metallic (Fe-EPS, Pd-EPS, FePd-EPS) complexes, by a combination of micro X-ray fluorescence, X-ray absorption spectroscopy methods (XANES and EXAFS), and transmission electron microscopy. The results show that iron in monometallic Fe-EPS and bimetalic FePd-EPS is in the mineralized form of iron oxides/hydroxides, predominantly in the form of Fe3+, with a small amount of Fe2+ in the structure, as a mixture of different nano-crystalline iron oxides and hydroxides. Palladium on the other hand is found as Pd(0) in the form of metallic nanoparticles with fcc structure in both, bi-metallic (FePd-EPS) and mono-metallic (Pd-EPS) species. In bi-metallic species Pd and Fe nanoparticles agglomerate in larger clusters, but they remain spatially separated. Access to the SR facilities at ESRF (beamline ID21, project LS-2225), DESY (beamline C) Hamburg (project I-20110511 EC) and ELETTRA (beamline XAFS, project 20115112) is acknowledged.
Found in: ključnih besedah
Summary of found: ...micro X-ray fluorescence, X-ray absorption spectroscopy methods ( XANES and EXAFS), and transmission electron microscopy. The...
Keywords: Klebsiella oxytoca, Fe, Pd, XANES, EXAFS, exopolysaccharide, FePd-EPS
Published: 28.06.2016; Views: 2876; Downloads: 0
.pdf Fulltext (388,27 KB)

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