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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: 2537; Downloads: 5
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: 2405; Downloads: 180
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: 1830; Downloads: 9
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: 1622; Downloads: 0
.pdf Fulltext (131,22 KB)

5.
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: 2163; Downloads: 25
.pdf Fulltext (18,40 MB)

6.
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: 1785; Downloads: 0
.pdf Fulltext (1,27 MB)

7.
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: 1332; Downloads: 70
URL Fulltext (0,00 KB)

8.
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: 2292; Downloads: 0
.pdf Fulltext (388,27 KB)

9.
Study of Li-S batteries by S K-edge RIXS spectroscopy
Robert Dominko, Iztok Arčon, Marko Petrič, Klemen Bučar, Matjaž Žitnik, Matjaž Kavčič, Alen Vižintin, 2016, published scientific conference contribution abstract

Abstract: Li-S batteries are considered as one of the most promising candidates for future batteries in applications where high energy density is required [1]. Despite that the general principle of operation is known for a long time [2], the lack of detailed understanding of relevant operation mechanisms has so far prevented their extensive use. A Li-S battery is composed of a lithium metal anode and a sulfur based cathode, separated by a porous separator wetted with electrolyte. During the battery cycle the reduction and oxidation of S to Li2S and back proceeds through a complicated equilibrium mixture of compounds that are typically dissolved in the electrolyte in the form of long and short chain polysulfides. In order to improve our understanding of polysulfide formation and its interactions within electrode, which are essential to achieve the long term cycling stability, development and application of new analytical tools is required. In this work sulfur K-edge resonant X-ray emission (RXES) measurements were performed on the Li-S battery in operando mode. The experiment was performed at the ID26 beamline at ESRF using the Johansson type tender x-ray emission spectrometer [3]. Full K-L RIXS maps were recorded on a set of chemically prepared Li2Sx sample standards characterized by different Li:S stoichiometric ratio, followed by the operando measurements on Li-S battery. Using the spectra recorded on Li2Sx standards two excitation energies were chosen and RXES spectra from the back of the battery cathode were sequentially acquired during one discharge cycle (C20). The relative amounts of each sulfur compound in the cathode during the discharge cycle were determined from the linear combination fit using measured reference standard spectra. Because of resonant excitation conditions the sensitivity for the polysulfide detection was significantly enhanced. Our work sets up S K-edge RIXS spectroscopy as an important analytical tool to study the mechanism of Li-polysulfide formation in the cathode and their interaction with the host matrix and electrolyte.
Found in: ključnih besedah
Summary of found: ...RIXS, RXES, Li-S battery, operando, Sulphur K-edge XANES, Lithium polysulphides, Li2S...
Keywords: RIXS, RXES, Li-S battery, operando, Sulphur K-edge XANES, Lithium polysulphides, Li2S
Published: 28.06.2016; Views: 2316; Downloads: 0
.pdf Fulltext (60,50 KB)

10.
Correlations between photocatalytic activity and chemical structure in copper doped TiO2-SiO2 with surface/incorporated Cu2+ sites
Tihana Čižmar, Iztok Arčon, Urška Lavrenčič Štangar, 2016, published scientific conference contribution abstract

Abstract: Sol−gel method was used to synthesize copper doped TiO2-SiO2 with varied dopant concentrations using tetraisopropoxide (TTIP) and copper acetlyacetonate (CuAcAc) as titania and copper sources. Structural information of Cu cation incorporation and its chemical state in the coatings are determined with Cu K-edge EXAFS and XANES analysis. The correlations between chemical state of the Cu dopant and the photocatalytic properties of the new active coatings are discussed.
Found in: ključnih besedah
Summary of found: ...are determined with Cu K-edge EXAFS and XANES analysis. The correlations between chemical state of...
Keywords: dip-coating, titanium dioxide, metal doping, Cu K-edge XANES, photocatalytic activity
Published: 07.07.2016; Views: 1933; Downloads: 0

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