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Author |
Pauwels, D.; Geboes, B.; Hereijgers, J.; Choukroun, D.; De Wael, K.; Breugelmans, T. |
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Title |
The application of an electrochemical microflow reactor for the electrosynthetic aldol reaction of acetone to diacetone alcohol |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Chemical engineering research and design |
Abbreviated Journal |
Chem Eng Res Des |
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Volume |
128 |
Issue |
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Pages |
205-213 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
The design and application of an electrochemical micro-flow reactor for the aldol reaction of acetone to diacetone alcohol (DAA) is reported. The modular reactor could be readily disassembled and reassembled to change the electrodes, incorporate a membrane and remove possible obstructions. The productivity and efficiency was quantified. Using a platinum deposit as electrocatalyst or an inert glassy carbon electrode as working electrode, the maximum obtainable equilibrium concentration of ±15 m% was reached after a single pass up to a flow rate of 8 ml min−1, yielding 0.57 g min−1 DAA (3.46 mmol cm−3 min−1) at an efficiency of 0.33 g C−1 on platinum and 0.50 g min−1 (3.04 mmol cm−3 min−1) at 1.20 g C−1 on glassy carbon. Note that no optimisation studies have been made in the present paper. |
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Wos |
000424736500018 |
Publication Date |
2017-10-20 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0263-8762 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.538 |
Times cited |
2 |
Open Access |
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Notes |
; The authors would like to thank Bert De Mot for assisting with the measurements. Jonas Hereijgers greatly acknowledges the Research Foundation – Flanders (FWO) for support through a Post-Doctoral grant (12Q8817N). ; |
Approved |
Most recent IF: 2.538 |
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Call Number  |
UA @ admin @ c:irua:146943 |
Serial |
5871 |
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Author |
Minjauw, M.M.; Solano, E.; Sree, S.P.; Asapu, R.; Van Daele, M.; Ramachandran, R.K.; Heremans, G.; Verbruggen, S.W.; Lenaerts, S.; Martens, J.A.; Detavernier, C.; Dendooven, J. |
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Title |
Plasma-enhanced atomic layer deposition of silver using Ag(fod)(PEt3) and NH3-plasma |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
29 |
Issue |
17 |
Pages |
7114-7121 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
A plasma-enhanced atomic layer deposition (ALD) process using the Ag(fod)(PEt3) precursor [(triethylphosphine)(6,6,7,7,8,8,8-heptafluoro-2,2-dimethy1-3,5-octanedionate)silver(I)] in combination with NH3-plasma is reported. The steady growth rate of the reported process (0.24 +/- 0.03 nm/cycle) was found to be 6 times larger than that of the previously reported Ag ALD process based on the same precursor in combination with H-2-plasma (0.04 +/- 0.02 nm/cycle). The ALD characteristics of the H-2-plasma and NH3-plasma processes were verified. The deposited Ag films were polycrystalline face-centered cubic Ag for both processes. The film morphology was investigated by ex situ scanning electron microscopy and grazing-incidence small-angle X-ray scattering, and it was found that films grown with the NH3-plasma process exhibit a much higher particle areal density and smaller particle sizes on oxide substrates compared to those deposited using the H-2-plasma process. This control over morphology of the deposited Ag is important for applications in catalysis and plasmonics. While films grown with the H-2-plasma process had oxygen impurities (similar to 9 atom %) in the bulk, the main impurity for the NH3-plasma process was nitrogen (similar to 7 atom %). In situ Fourier transform infrared spectroscopy experiments suggest that these nitrogen impurities are derived from NH surface groups generated during the NH3-plasma, which interact with the precursor molecules during the precursor pulse. We propose that the reaction of these surface groups with the precursor leads to additional deposition of Ag atoms during the precursor pulse compared to the H-2-plasma process, which explains the enhanced growth rate of the NH3-plasma process. |
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Wos |
000410868600012 |
Publication Date |
2017-08-09 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
9 |
Open Access |
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Notes |
; M.M.M. and J.D. acknowledge the Fonds Wetenschappelijk Onderzoek Vlaanderen (FWO Vlaanderen) for financial support through a personal research grant. We also acknowledge FWO Vlaanderen for providing project funding for this work. We are grateful to the ESRF staff for smoothly running the synchrotron and beamline facilities. We also thank Olivier Janssens for performing the SEM measurements and Stefaan Broekaert for mechanical assistance. J.A.M. acknowledges the Flemish Government for long-term structural funding (Methusalem). ; |
Approved |
Most recent IF: 9.466 |
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Call Number |
UA @ admin @ c:irua:146757 |
Serial |
5983 |
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Author |
Bottari, F.; De Wael, K. |
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Title |
Electrodeposition of gold nanoparticles on boron doped diamond electrodes for the enhanced reduction of small organic molecules |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Journal of electroanalytical chemistry : an international journal devoted to all aspects of electrode kynetics, interfacial structure, properties of electrolytes, colloid and biological electrochemistry. |
Abbreviated Journal |
J Electroanal Chem |
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Volume |
801 |
Issue |
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Pages |
521-526 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The performance of gold nanoparticles electrodeposited on boron doped diamond (BDD) electrodes was investigated in respect to the reduction of chloramphenicol (CAP), an antibiotic of the phenicols family. The chosen deposition protocol, three nucleation-growing pulses, shows a remarkable surface coverage, with an even distribution of average-sized gold particles (~ 50 nm), and it was proven capable of generating a three-fold increase in the CAP reduction current. A calibration plot for CAP detection was obtained in the micromolar range (535 μM) with good correlation coefficient (0.9959) and an improved sensitivity of 0.053 μA μM− 1 mm− 2 compared to the electrochemistry of CAP at a bare BDD electrode. |
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Wos |
000411847500065 |
Publication Date |
2017-08-02 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1572-6657 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.012 |
Times cited |
4 |
Open Access |
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Notes |
; This work was financially supported by the University of Antwerp (BOF) and the Research Foundation Flanders (FWO) (project G037415N). ; |
Approved |
Most recent IF: 3.012 |
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Call Number |
UA @ admin @ c:irua:146372 |
Serial |
5600 |
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Author |
Cuypers, B.; Vermeylen, S.; Hammerschmid, D.; Trashin, S.; Rahemi, V.; Konijnenberg, A.; De Schutter, A.; Cheng, C.-H.C.; Giordano, D.; Verde, C.; De Wael, K.; Sobott, F.; Dewilde, S.; Van Doorslaer, S. |
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Title |
Antarctic fish versus human cytoglobins : the same but yet so different |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Journal of inorganic biochemistry |
Abbreviated Journal |
J Inorg Biochem |
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Volume |
173 |
Issue |
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Pages |
66-78 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The cytoglobins of the Antarctic fish Chaenocephalus aceratus and Dissostichus mawsoni have many features in common with human cytoglobin. These cytoglobins are heme proteins in which the ferric and ferrous forms have a characteristic hexacoordination of the heme iron, i.e. axial ligation of two endogenous histidine residues, as confirmed by electron paramagnetic resonance, resonance Raman and optical absorption spectroscopy. The combined spectroscopic analysis revealed only small variations in the heme-pocket structure, in line with the small variations observed for the redox potential. Nevertheless, some striking differences were also discovered. Resonance Raman spectroscopy showed that the stabilization of an exogenous heme ligand, such as CO, occurs differently in human cytoglobin in comparison with Antarctic fish cytoglobins. Furthermore, while it has been extensively reported that human cytoglobin is essentially monomeric and can form an intramolecular disulfide bridge that can influence the ligand binding kinetics, 3D modeling of the Antarctic fish cytoglobins indicates that the cysteine residues are too far apart to form such an intramolecular bridge. Moreover, gel filtration and mass spectrometry reveal the occurrence of non-covalent multimers (up to pentamers) in the Antarctic fish cytoglobins that are formed at low concentrations. Stabilization of these oligomers by disulfide-bridge formation is possible, but not essential. If intermolecular disulfide bridges are formed, they influence the heme-pocket structure, as is shown by EPR measurements. |
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Wos |
000405159600007 |
Publication Date |
2017-04-28 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0162-0134 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.348 |
Times cited |
7 |
Open Access |
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Notes |
; The authors acknowledge the support of the University of Antwerp GOA-BOF funding (28312), FWO funding (G.0687.13) and the Hercules foundation for funding of the Synapt G2 instrument. This study was carried out in the framework of the SCAR program “Antarctic Thresholds – Ecosystem Resilience and Adaptation” (AnT-ERA). It was financially supported by the Italian National Program for Antarctic Research (PNRA). Research of A. De Schutter is funded by a PhD grant of the Agency for Innovation by Science and Technology (121339) (IWT, Belgium). C-H C. Cheng acknowledges funding support from US National Science Foundation Polar Programs (ANT-1142158). ; |
Approved |
Most recent IF: 3.348 |
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Call Number |
UA @ admin @ c:irua:144826 |
Serial |
5474 |
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Author |
Ricciardi, P.; Legrand, S.; Bertolotti, G.; Janssens, K. |
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Title |
Macro X-ray fluorescence (MA-XRF) scanning of illuminated manuscript fragments: potentialities and challenges |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Microchemical journal
T2 – TECHNART Conference, APR 27-30, 2015, Catania, ITALY |
Abbreviated Journal |
Microchem J |
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Volume |
124 |
Issue |
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Pages |
785-791 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Macro X-ray fluorescence scanning (MA-XRF) is gradually becoming an established technique for the non-invasive analytical investigation of painted surfaces. This paper discusses some of the benefits and limitations of employing MA-XRF for the study of manuscript illuminations. Art historical research on this type of artefacts that is based on scientific measurements is often limited by the fact that usually no sampling can take place. Hence there is a need for non-invasive analytical tools that make it possible to conduct systematic investigations. As a representative example of this type of objects, a 15th century Italian manuscript fragment from the collection of the Fitzwilliam Museum in Cambridge (UK) is investigated. The aims of the study were to gain insight into the materials and techniques employed by Renaissance illuminators and to help answer specific questions regarding the fragment's authorship and geographic origin. The complementarity and advantages of MA-XRF mapping versus site-specific analyses are discussed. For this purpose, MA-XRF data are evaluated and compared with the results of other analytical techniques. The interpretation of the elemental maps is discussed along with the challenges faced during the analysis. (C) 2015 Elsevier B.V. All rights reserved. |
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Wos |
000367755600096 |
Publication Date |
2015-10-27 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
24 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:144767 |
Serial |
5698 |
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Author |
Loreto, S.; Cuypers, B.; Brokken, J.; Van Doorslaer, S.; De Wael, K.; Meynen, V. |
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Title |
The effect of the buffer solution on the adsorption and stability of horse heart myoglobin on commercial mesoporous titanium dioxide : a matter of the right choice |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
19 |
Issue |
21 |
Pages |
13503-13514 |
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Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Despite the numerous studies on the adsorption of different proteins onto mesoporous titanium dioxide and indications on the important role of buffer solutions in bioactivity, a systematic study on the impact of the buffer on the protein incorporation into porous substrates is still lacking. We here studied the interaction between a commercial mesoporous TiO2 and three of the most used buffers for protein incorporation, i.e. HEPES, Tris and phosphate buffer. In addition, this paper analyzes the adsorption of horse heart myoglobin (hhMb) onto commercial mesoporous TiO2 as a model system to test the influence of buffers on the protein incorporation behavior in mesoporous TiO2. N2 sorption analysis, FT-IR and TGA/DTG measurements were used to evaluate the interaction between the buffers and the TiO2 surface, and the effect of such an interaction on hhMb adsorption. Cyclic voltammetry (CV) and electron paramagnetic resonance (EPR) were used to detect changes in the microenvironment surrounding the heme. The three buffers show a completely different interaction with the TiO2 surface, which drastically affects the adsorption of myoglobin as well as its structure and electrochemical activity. Therefore, special attention is required while choosing the buffer medium to avoid misguided evaluation of protein adsorption on mesoporous TiO2. |
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Wos |
000402488300013 |
Publication Date |
2017-04-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
2 |
Open Access |
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Notes |
; We are grateful to Gert Nuyts for performing the XRF measurements, and Dr Stanislav Trashin for his assistance during the electrochemical experiments. This work is supported by the Research Foundation – Flanders (FWO) (grant G.0687.13) and the University of Antwerp (BOF project). ; |
Approved |
Most recent IF: 4.123 |
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Call Number |
UA @ admin @ c:irua:143514 |
Serial |
5582 |
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Author |
van der Snickt, G.; Dubois, H.; Sanyova, J.; Legrand, S.; Coudray, A.; Glaude, C.; Postec, M.; van Espen, P.; Janssens, K. |
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Title |
Large-area elemental imaging reveals Van Eyck's original paint layers on the Ghent altarpiece (1432), rescoping its conservation treatment |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
56 |
Issue |
17 |
Pages |
4797-4801 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
A combination of large-scale and micro-scale elemental imaging, yielding elemental distribution maps obtained by, respectively non-invasive macroscopic X-ray fluorescence (MA-XRF) and by secondary electron microscopy/energy dispersive X-ray analysis (SEM-EDX) and synchrotron radiation-based micro-XRF (SR m-XRF) imaging was employed to reorient and optimize the conservation strategy of van Eyck's renowned Ghent Altarpiece. By exploiting the penetrative properties of X-rays together with the elemental specificity offered by XRF, it was possible to visualize the original paint layers by van Eyck hidden below the overpainted surface and to simultaneously assess their condition. The distribution of the high-energy Pb-L and Hg-L emission lines revealed the exact location of hidden paint losses, while Fe-K maps demonstrated how and where these lacunae were filled-up using an iron-containing material. The chemical maps nourished the scholarly debate on the overpaint removal with objective, chemical arguments, leading to the decision to remove all skillfully applied overpaints, hitherto interpreted as work by van Eyck. MA-XRF was also employed for monitoring the removal of the overpaint during the treatment phase. To gather complementary information on the in-depth layer build-up, SEM-EDX and SR mu-XRF imaging was used on paint cross sections to record microscale elemental maps. |
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Corporate Author |
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Wos |
000398576000019 |
Publication Date |
2017-03-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1433-7851; 0570-0833 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
11 |
Open Access |
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Notes |
; This research was supported by the Baillet Latour fund, the Belgian Science Policy Office (Projects MO/39/011) and the Gieskes-Strijbis fund. The authors are also indebted to the BOF-GOA SOLAR Paint project of the University of Antwerp Research Council. The church wardens of the cathedral of St. Bavo and their chairman L. Collin are acknowledged for this agreeable collaboration. We also wish to thank conservators L. Depuydt, B. De Volder, F. Rosier, N. Laquiere and G. Steyaert as well as the members of the international committee. We are indebted to Prof. Em. A. Van Grevenstein-Kruse. ; |
Approved |
Most recent IF: 11.994 |
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Call Number |
UA @ admin @ c:irua:142376 |
Serial |
5688 |
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Author |
Verbruggen, S.W.; Van Hal, M.; Bosserez, T.; Rongé, J.; Hauchecorne, B.; Martens, J.A.; Lenaerts, S. |
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Title |
Harvesting hydrogen gas from air pollutants with an un-biased gas phase photo-electrochemical cell |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
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Volume |
10 |
Issue |
7 |
Pages |
1413-1418 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The concept of an all-gas-phase photo-electrochemical cell (PEC) producing hydrogen gas from volatile organic contaminated gas and light is presented. Without applying any external bias, organic contaminants are degraded and hydrogen gas is produced in separate electrode compartments. The system works most efficiently with organic pollutants in inert carrier gas. In the presence of oxygen gas, the cell performs less efficiently but still significant photocurrents are generated, showing the cell can be run on organic contaminated air. The purpose of this study is to demonstrate new application opportunities of PEC technology and to encourage further advancement toward photo-electrochemical remediation of air pollution with the attractive feature of simultaneous energy recovery and pollution abatement. |
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Place of Publication |
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Language |
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Wos |
000398838600017 |
Publication Date |
2017-02-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1864-5631 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.226 |
Times cited |
6 |
Open Access |
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Notes |
; S.W.V. and J.R. acknowledge the Research Foundation-Flanders (FWO) for a postdoctoral fellowship. T.B. and J.A.M. acknowledge the Flemish government for long-term structural funding (Methusalem). Nicolaas Schewyck is greatly thanked for his experimental work during his master thesis. ; |
Approved |
Most recent IF: 7.226 |
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Call Number |
UA @ admin @ c:irua:140922 |
Serial |
5955 |
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Author |
van Walsem, J.; Verbruggen, S.W.; Modde, B.; Lenaerts, S.; Denys, S. |
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Title |
CFD investigation of a multi-tube photocatalytic reactor in non-steady-state conditions |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
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Volume |
304 |
Issue |
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Pages |
808-816 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
A novel multi-tube photoreactor is presented with a high efficiency (over 90% conversion) toward the degradation of acetaldehyde in air under UV conditions with an incident intensity of 2.1 mW cm−2. A CFD model was developed to simulate the transient adsorption and photocatalytic degradation processes of acetaldehyde in this reactor design and to estimate the corresponding kinetic parameters through an optimization routine using the experimentally determined outlet concentration profiles. The CFD model takes into account the entire reactor geometry and all relevant flow parameters, in contrast to analytical methods that often oversimplify the physical and chemical process characteristics. Using CFD, we show that both adsorption and desorption rate constants increase by respectively one and two orders of magnitude when the UV light is switched on, which clearly affects the transient behavior. The agreement of the experimental and modelled concentration profiles is excellent as evidenced by a coefficient of determination of at least 0.965. To demonstrate the reliability and accuracy of all parameters obtained from the modelling approach, an ultimate validation test was performed using other conditions than the ones used for estimating the kinetic parameters. The model was able to accurately simulate simultaneous adsorption, desorption and photocatalytic degradation. |
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Place of Publication |
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Wos |
000384777200089 |
Publication Date |
2016-07-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1385-8947; 1873-3212 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.216 |
Times cited |
10 |
Open Access |
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Notes |
; J.V.W. acknowledges the Agentschap Innoveren & Ondernemen for a PhD fellowship. S.W.V. acknowledges the Research Foundation – Flanders (FWO) for a postdoctoral fellowship. ; |
Approved |
Most recent IF: 6.216 |
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| |
Call Number |
UA @ admin @ c:irua:139620 |
Serial |
5933 |
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| Permanent link to this record |
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| |
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Author |
Pilehvar, S.; Reinemann, C.; Bottari, F.; Vanderleyden, E.; Van Vlierberghe, S.; Blust, R.; Strehlitz, B.; De Wael, K. |
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| |
Title |
A joint action of aptamers and gold nanoparticles chemically trapped on a glassy carbon support for the electrochemical sensing of ofloxacin |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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| |
Volume |
240 |
Issue |
|
Pages |
1024-1035 |
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| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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| |
Abstract |
A joint action of ssDNA aptamers and electrochemistry is a key element in developing successful biosensing platforms, since aptamers are capable of binding various targets with high specificity, and electrochemistry is one of the most sensitive techniques for on-site detections. A continuous search for improved immobilization and sensing strategies of aptamers on transducer surfaces resulted in the strategy presented in this article. The strategy is based on the covalent attachment of gold nanoparticles on the surface of glassy carbon electrodes through sulfhydryl-terminated monolayer, acting as a glue to connect AuNPs on the electrode. The covalently attached gold nanoparticles modified glassy carbon electrodes have been applied for the efficient immobilization of thiolated ssDNA probes, with a surface coverage of about 8.54 × 1013 molecules cm−2 which was 7-fold higher than that on the electrochemically deposited gold nanoparticles. Consequently, improved sensitivity, good reproducibility and stability are achieved for electrochemical aptasensor. Combined with the high affinity and specificity of an aptamer, a simple, novel, rapid, sensitive and label-free electrochemical aptasensor was successfully fabricated for ofloxacin (OFL) detection. The linear dynamic range of the sensor varies between 5 × 10−8 to 2 × 10−5 M OFL with a detection limit of 1 × 10−9 M OFL. A potential application in environmental monitoring was demonstrated by using this sensing strategy for the determination of OFL in (experimentally spiked) real samples such as tap water and effluent of sewage treatment plant. The proposed nanoaptasensor combines the advantages of the covalent attachment of neatly arranged AuNPs (enlarged active surface area and strengthened electrochemical signal) and the elimination of labels for the amplified detection of OFL, with the covalent attachment of highly specific aptamers to the surface of the modified electrode. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000390622300123 |
Publication Date |
2016-09-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
5.401 |
Times cited |
21 |
Open Access |
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| |
Notes |
; This work was financially supported by the University of Antwerp (BOF), The Research Foundation – Flanders (FWO) and The Hercules Foundation. S. P. is thankful to UA for DOCPRO financial support. C.R. and B.S. acknowledge funding by the Federal Ministry of Education and Research (BMBF) under contract no. 03X0094B. ; |
Approved |
Most recent IF: 5.401 |
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| |
Call Number |
UA @ admin @ c:irua:135410 |
Serial |
5682 |
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| Permanent link to this record |
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Author |
Pauwels, D.; Pilehvar, S.; Geboes, B.; Hubin, A.; De Wael, K.; Breugelmans, T. |
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| |
Title |
A new multisine-based impedimetric aptasensing platform |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Electrochemistry communications |
Abbreviated Journal |
Electrochem Commun |
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| |
Volume |
71 |
Issue |
|
Pages |
23-27 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Applied Electrochemistry & Catalysis (ELCAT) |
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| |
Abstract |
In this work an aptamer-based biosensor is combined with a multisine electrochemical impedance spectroscopy sensing methodology into a novel and promising biosensing strategy. Employing a multisine instead of a traditional single sine measuring method allows the detection and quantification of parameters that provide information about the accuracy and reliability of the results, such as noise and distortions. This does not only lead to a shorter measurement time, but it also enables an easy and fast evaluation of the quality of the data and fitting, leading to more accurate results. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000383445000006 |
Publication Date |
2016-07-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1388-2481; 1873-1902 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.396 |
Times cited |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 4.396 |
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| |
Call Number |
UA @ admin @ c:irua:134765 |
Serial |
5746 |
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| Permanent link to this record |
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Author |
Trashin, S.; De Jong, M.; Luyckx, E.; Dewilde, S.; De Wael, K. |
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Title |
Electrochemical evidence for neuroglobin activity on NO at physiological concentrations |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of biological chemistry |
Abbreviated Journal |
J Biol Chem |
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| |
Volume |
291 |
Issue |
36 |
Pages |
18959-18966 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The true function of neuroglobin (Ngb) and, particularly, human Ngb (NGB) has been under debate since its discovery 15 years ago. It has been expected to play a role in oxygen binding/supply, but a variety of other functions have been put forward, including NO dioxygenase activity. However, in vitro studies that could unravel these potential roles have been hampered by the lack of an Ngb-specific reductase. In this work, we used electrochemical measurements to investigate the role of an intermittent internal disulfide bridge in determining NO oxidation kinetics at physiological NO concentrations. The use of a polarized electrode to efficiently interconvert the ferric (Fe3+) and ferrous (Fe2+) forms of an immobilized NGB showed that the disulfide bridge both defines the kinetics of NO dioxygenase activity and regulates appearance of the free ferrous deoxy-NGB, which is the redox active form of the protein in contrast to oxy-NGB. Our studies further identified a role for the distal histidine, interacting with the hexacoordinated iron atom of the heme, in oxidation kinetics. These findings may be relevant in vivo, for example in blocking apoptosis by reduction of ferric cytochrome c, and gentle tuning of NO concentration in the tissues. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000383242300031 |
Publication Date |
2016-07-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-9258; 1083-351x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.125 |
Times cited |
11 |
Open Access |
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Notes |
; This work was supported by Fonds Wetenschappelijk Onderzoek (FWO) Grant G.0687.13 and Universiteit Antwerpen GOA BOF 28312. The authors declare that they have no conflicts of interest with the contents of this article. ; |
Approved |
Most recent IF: 4.125 |
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| |
Call Number |
UA @ admin @ c:irua:134340 |
Serial |
5590 |
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| Permanent link to this record |
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Author |
Janssens, K.; van der Snickt, G.; Alfeld, M.; Noble, P.; van Loon, A.; Delaney, J.; Conover, D.; Zeibel, J.; Dik, J. |
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Title |
Rembrandt's 'Saul and David' (c. 1652) : use of multiple types of smalt evidenced by means of non-destructive imaging |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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| |
Volume |
126 |
Issue |
|
Pages |
515-523 |
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| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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| |
Abstract |
The painting Saul and David, considered to date from c. 1652 and previously attributed to Rembrandt van Rijn and/or his studio, is a complex work of art that has been recently subjected to intensive investigation and conservation treatment. The goal of the research was to give insight into the painting's physical construction and condition in preparation for conservation treatment. It was also anticipated that analysis would shed light on authenticity questions and Rembrandt's role in the creation of the painting. The painting depicts the Old Testament figures of King Saul and David. At left is Saul, seated, holding a spear and wiping a tear from his eye with a curtain. David kneels before him at the right playing his harp. In the past, the large sections with the life-size figures were cut apart and later reassembled. A third piece of canvas was added to replace a missing piece of canvas above the head of David. As part of the investigation into the authenticity of the curtain area, a number of paint micro samples were examined with LM and SEM-EDX. Given that the earth, smalt and lake pigments used in the painting could not be imaged with traditional imaging techniques, the entire painting was also examined with state of the art non-destructive imaging techniques. Special attention was devoted to the presence of cobalt-containing materials, specifically the blue glass pigment smalt considered characteristic for the late Rembrandt. A combination of quantitative electron microprobe analysis and macroscopic X-ray fluorescence scanning revealed that three types of cobalt-containing materials are present in the painting. The first type is a cobalt drier that was found in the overpaint used to cover up the canvas inset and the joins that were added in the 19th century. The other two Co-containing materials are part of the original paint used by Rembrandt and comprise two varieties of smalt, a K-rich glass pigment that derives its gray-blue color by doping with Co-ions. Smalt paint with a higher Ni content (NiO:CoO ratio of around 1:4) was used to depict the blue stripes in Saul's colorful turban, while smalt with a lower Ni content was employed (NiO:CoO ratio of around 1:5) for the broad expanses of Saul's garments. The presence of two types of smalt not only supports the recent re-attribution of the painting to Rembrandt, but also that the picture was painted in two phases. Saul's dark red garment is painted in a rough, “loose” manner and the now discolored smalt-rich layer was found to have been partially removed during a past restoration treatment/s. In contrast, the blue-green smalt in the turban is much better preserved and provides a colorful accent. While the use of different types of smalt in a Rembrandt painting has been previously identified using quantitative EDX analysis of paint cross-sections, to the best of our knowledge this is the first time such a distinction has been observed in a 17th-century painting using non-destructive imaging techniques. In addition to the XRF-based non-invasive elemental mapping, hyperspectral imaging in the visual to near-infrared (VNIR) region was also carried out. (C) 2016 Elsevier B.V. All rights reserved. |
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Place of Publication |
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Language |
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Wos |
000373647500063 |
Publication Date |
2016-01-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
18 |
Open Access |
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| |
Notes |
; This research is part of the ReVisualising late Rembrandt: Developing and Applying New Imaging Techniques research project, supported by the Science4Arts research program of the Netherlands Organisation for Scientific Research (NWO, The Hague, NL, ReVisRembrandt project) and the National Science Foundation (NSF, Washington DC, USA, award 1041827). We would like to thank colleagues of the Mauritshuis (The Hague, NL) and the Dutch Cultural Heritage Agency (RCE) in Rijswijk, NL for their support and assistance during the scanning of the Saul and David painting. The GOA project “SOLARPAINT” (University of Antwerp) and the Fund Baillet Latour (Brussels, B) are acknowledged for financial support to GvdS and KJ. We also like to acknowledge the help of Eliza Longhini and Stijn Legrand during some of the XRF scanning stages. ; |
Approved |
Most recent IF: 3.034 |
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| |
Call Number |
UA @ admin @ c:irua:133258 |
Serial |
5813 |
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| Permanent link to this record |
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Author |
Trashin, S.; De Jong, M.; Meynen, V.; Dewilde, S.; De Wael, K. |
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Title |
Attaching redox proteins onto electrode surfaces by bis-silane |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
ChemElectroChem |
Abbreviated Journal |
Chemelectrochem |
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Volume |
3 |
Issue |
7 |
Pages |
1035-1038 |
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Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Immobilization of redox proteins on electrode surfaces is of special interest for mechanistic studies and applications because of a well-controlled redox state of protein molecules by a polarized electrode and fast electron transfer kinetics, free from diffusion limitation. Here, bis-organosilane (1,2-bis(trimethoxysilyl)ethane) was applied as a fresh solution in a pH 7 phosphate buffer without use of any organic solvent, sol-gel or mesoporous bulk matrix. A short aging period of 30 minutes before deposition on the electrodes was optimal for the immobilization of proteins. Three redox proteins (cytochrome c, neuroglobin and GLB-12) were confined to the gold surface of electrodes with high coverages and stability, indicating that the suggested technique is simple, efficient and generic in nature. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000380043500001 |
Publication Date |
2016-03-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2196-0216 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.136 |
Times cited |
4 |
Open Access |
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Notes |
; The authors thank the Fund for Scientific Research-Flanders (FWO) (Grant G.0687.13) and the GOA-BOF UA 2013-2016 (project ID 28312) for funding. ; |
Approved |
Most recent IF: 4.136 |
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Call Number |
UA @ admin @ c:irua:132628 |
Serial |
5485 |
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| Permanent link to this record |
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Author |
Thirumalraj, alamurugan; Palanisamy, S.; Chen, S.-M.; De Wael, K. |
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Title |
A graphene/gelatin composite material for the entrapment of hemoglobin for bioelectrochemical sensing applications |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of the electrochemical society |
Abbreviated Journal |
J Electrochem Soc |
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Volume |
163 |
Issue |
7 |
Pages |
265-271 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In the present work, a novel graphene (GN) and gelatin (GTN) composite was prepared and used as an immobilization matrix for hemoglobin (Hb). Compared with Hb immobilized on a bare, GN or GTN modified glassy carbon electrode (GCE), a stable and pair of well-defined quasi redox couple was observed at an Hb modified GN/GTN composite GCE at a formal potential of −0.306 V versus Ag|AgCl. The direct electrochemical behavior of Hb was greatly enhanced by the presence of both GTN and GN. A heterogeneous electron transfer rate constant (Ks) was calculated as 3.82 s−1 for Hb immobilized at GN/GTN modified GCE, which indicates the fast direct electron transfer of Hb toward the electrode surface. The biosensor shows a stable and wide linear response for H2O2 in the linear response range from 0.1 μM to 786.6 μM with an analytical sensitivity and limit of detection of 0.48 μAμM−1 cm−2 and 0.04 μM, respectively. The fabricated biosensor holds its high selectivity in the presence of potentially active interfering species and metal ions. The biosensor shows its satisfactory practical ability in the commercial contact lens solution and human serum samples. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000377412900047 |
Publication Date |
2016-04-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0013-4651 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.259 |
Times cited |
9 |
Open Access |
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Notes |
; This project was supported by the Ministry of Science and Technology (project no. NSC1012113M027001MY3), Taiwan (Republic of China). The authors express their sincere thanks to Prof. Bih-Show Lou, Chemistry Division, Center for General Education, Chang Gung University, Tao-Yuan, Taiwan for providing the human serum samples. ; |
Approved |
Most recent IF: 3.259 |
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| |
Call Number |
UA @ admin @ c:irua:132627 |
Serial |
5635 |
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| Permanent link to this record |
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Author |
Monico, L.; Janssens, K.; Hendriks, E.; Vanmeert, F.; van der Snickt, G.; Cotte, M.; Falkenberg, G.; Brunetti, B.G.; Miliani, C. |
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Title |
Evidence for degradation of the chrome yellows in Van Gogh's sunflowers : a study using noninvasive in situ methods and synchrotron-radiation-based x-ray techniques |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
54 |
Issue |
47 |
Pages |
13923-13927 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron-radiation-based X-ray investigations of two microsamples, revealed the presence of different types of chrome yellow used by Van Gogh, including the lightfast PbCrO4 and the sulfur-rich PbCr1-xSxO4 (x approximate to 0.5) variety that is known for its high propensity to undergo photoinduced reduction. The products of this degradation process, i.e., Cr-III compounds, were found at the interface between the paint and the varnish. Selected locations of the painting with the highest risk of color modification by chemical deterioration of chrome yellow are identified, thus calling for careful monitoring in the future. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000367722500009 |
Publication Date |
2015-10-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1433-7851; 0570-0833 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
24 |
Open Access |
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Notes |
; We acknowledge financial support from the Italian MIUR project SICH-PRIN (2010329WPF_001) and BELSPO (Brussels) Project S2-ART (SD04A), GOA “SOLARPAINT” (Research Fund Antwerp University, BOF-2015), and FWO (Brussels) projects G.0C12.13, G.0704.08, G.01769.09. We thank ESRF (EC-1051, HG-26) and DESY (I-20120312 EC) for beamtime grants received. Noninvasive analysis of Sunflowers were supported by the EU FP7 programme CHARISMA (Grant 228330) and the Fund Inbev-Baillet Latour (Brussels). L.M. acknowledges financial support from the CNR Short Term Mobility Programme-2013. We thank Muriel Geldof, Luc Megens, Suzan de Groot (The Netherlands Cultural Heritage Agency, RCE), Chiara Grazia, David Buti (CNR-ISTM and SMAArt Centre), and the staff of the Van Gogh Museum for their collaboration. ; |
Approved |
Most recent IF: 11.994; 2015 IF: 11.261 |
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Call Number |
UA @ admin @ c:irua:131110 |
Serial |
5617 |
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Author |
van der Snickt, G.; Legrand, S.; Caen, J.; Vanmeert, F.; Alfeld, M.; Janssens, K. |
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Title |
Chemical imaging of stained-glass windows by means of macro X-ray fluorescence (MA-XRF) scanning |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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| |
Volume |
124 |
Issue |
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Pages |
615-622 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
Since the recent development of a mobile setup, MA-XRF scanning proved a valuable tool for the non-invasive, technical study of paintings. In this work, the applicability of MA-XRF scanning for investigating stained-glass windows inside a conservation studio is assessed by analysis of a high-profile, well-studied late-mediaeval panel. Although accurate quantification of components is not feasible with this analytical imaging technique, plotting the detected intensities of K versus Ca in a scatter plot allowed distinguishing glass fragments of different compositional types within the same panel. In particular, clusters in the Ca/K correlation plot revealed the presence of two subtypes of potash glass and three subtypes of high lime low alkali glass. MA-XRF results proved consistent with previous quantitative SEM-EDX analysis on two samples and analytical-based theories on glass production in the Low Countries formulated in literature. A bi-plot of the intensities of the more energetic Rb-K versus Sr-K emission lines yielded a similar glass type differentiation and is here presented as suitable alternative in case the Ca/K signal ratio is affected by superimposed weathering crusts. Apart from identification of the chromophores responsible for the green, blue and red glass colors, contrasting the associated elemental distribution maps obtained on the exterior and interior side of the glass permitted discriminating between colored pot metal glass and multi-layered flashed glass as well. Finally, the benefit of obtaining compositional information from the entire surface, as opposed to point analysis, was illustrated by the discovery of what appears to be a green cobalt glass a feature that was previously missed on this well-studied stained-glass window, both by connoisseurs and spectroscopic sample analysis. (C) 2015 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000367755600074 |
Publication Date |
2015-10-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
22 |
Open Access |
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Notes |
; The staff of the Museums of the City of Bruges, i.e. Director Till-Holger Borchert and Deputy Curator Kristel Van Audenaeren, are acknowledged for this pleasant collaboration and the authorization for the publication of the images in this article. This research was supported by the InBev-Baillet Latour fund. ; |
Approved |
Most recent IF: 3.034 |
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| |
Call Number |
UA @ admin @ c:irua:131100 |
Serial |
5514 |
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| Permanent link to this record |
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Author |
Monico, L.; Janssens, K.; Cotte, M.; Sorace, L.; Vanmeert, F.; Brunetti, B.G.; Miliani, C. |
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Title |
Chromium speciation methods and infrared spectroscopy for studying the chemical reactivity of lead chromate-based pigments in oil medium |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Microchemical journal
T2 – TECHNART Conference, APR 27-30, 2015, Catania, ITALY |
Abbreviated Journal |
Microchem J |
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Volume |
124 |
Issue |
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Pages |
272-282 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Environmental factors, such as light, humidity and temperature are triggering agents for the alteration of organic and/or inorganic constituents of oil paintings. The oxidation of the organic material is favored by increasing of relative humidity and temperature, whereas processes involving changes of the oxidation states of a number of inorganic pigments (e.g., vermilion, cadmium yellows, zinc yellows, chrome yellows) are mainly activated by light-exposure. In view of the optimization of the long-term conservation and restoration strategies of paintings it is of relevant interest to establish the consequences of thermal parameters (temperature and relative humidity) on the chemical/photochemical-reactivity and the nature of the alteration products of light sensitive-pigments in oil medium. To this aim here we propose a multi-method analytical approach based on the combination of diffuse reflectance UV-Vis, FTIR, synchrotron radiation (SR)-based micro X-ray fluorescence (mu-XRF)/micro-X-ray absorption neat edge structure ()CANES) and electron paramagnetic resonance (EPR) spectroscopies for studying the effects of different relative humidity conditions before and after light exposure on the reactivity of a series of lead chromate-based pigments [such as PbCrO4 center dot PbO (monoclinic), PbCrO4 (monoclinic) and PbCr0.2S0.8O4 (orthorhombic)] in an oil medium. The investigation of paint models was also compared to that of a late 19th century historical orthorhombic PbCr0.4S0.6O4 oil paint. Diffuse reflectance UV-Vis and FTIR spectroscopies were used to obtain information associated with chromatic changes and the formation of organo-metal degradation products at the paint surface. SR-based Cr K-edge mu-XANES/mu-XRF mapping analysis and EPR spectroscopy were employed in a complementary fashion to determine the amount, nature and distribution of Cr(III) and Cr(V)-based alteration compounds within the paints with micrometric spatial resolution. Under the employed thermal aging conditions, lead(II)-carboxylates and reduced Cr-compounds (in abundance of up to about 35% at the surface) have been identified in the lead chromate-based paints. The tendency of chromates to become reduced increased with increasing moisture levels and was favored for the orthorhombic PbCr0.2S0.8O4 compounds. The redox process gave rise to the formation of Cr(V)-species in relative amount much higher than that was formed in the equivalent paint which was exposed only to light. After light-exposure of the thermally aged paints, compounds ascribable to the oxidation of the organic binder were detected for all the types of pigments. Nevertheless, the previous thermal treatment increased the tendency toward photo-reduction of only the PbCr0.2S0.8O4 pigment. For this light-sensitive compound, the thickness variation of the reduced Cr-rich (ca. 70%) photo-alteration layer with moisture levels could be ascribed to a surface passivation phenomenon that had already occurred before photochemical aging. (C) 2015 Elsevier B.V. All rights reserved. |
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Place of Publication |
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Editor |
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Wos |
000367755600042 |
Publication Date |
2015-09-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
23 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:131099 |
Serial |
5519 |
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| Permanent link to this record |
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Author |
Verbruggen, S.W.; Keulemans, M.; van Walsem, J.; Tytgat, T.; Lenaerts, S.; Denys, S. |
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Title |
CFD modeling of transient adsorption/desorption behavior in a gas phase photocatalytic fiber reactor |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
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| |
Volume |
292 |
Issue |
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Pages |
42-50 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
We present the use of computational fluid dynamics (CFD) for accurately determining the adsorption parameters of acetaldehyde on photocatalytic fiber filter material, integrated in a continuous flow system. Unlike the traditional analytical analysis based on Langmuir adsorption, not only steady-state situations but also transient phenomena can be accounted for. Air displacement effects in the reactor and gas detection cell are investigated and inherently made part of the model. Incorporation of a surface aldol condensation reaction in the CFD analysis further improves the accuracy of the model which enables to extract precise, intrinsic adsorption parameters for situations in which analytical analysis would otherwise fail. |
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Place of Publication |
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Editor |
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Language |
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Wos |
000373648000005 |
Publication Date |
2016-02-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1385-8947; 1873-3212 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.216 |
Times cited |
12 |
Open Access |
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Notes |
; S.W.V. acknowledges the Research Foundation – Flanders (FWO) for a postdoctoral fellowship. M.K. acknowledges the IWT for a Ph.D. fellowship. Konstantina Kalafata and Ioanna Fasaki are greatly thanked for providing the NanoPhos suspension. Bioscience Engineering bachelor students M. Gerritsma, J. Helsen and Y. Riahi Drif are thanked for their assistance in performing the adsorption experiments. ; |
Approved |
Most recent IF: 6.216 |
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Call Number |
UA @ admin @ c:irua:130876 |
Serial |
5934 |
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| Permanent link to this record |
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Author |
De Jong, M.; Sleegers, N.; Kim, J.; Van Durme, F.; Samyn, N.; Wang, J.; De Wael, K. |
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Title |
Electrochemical fingerprint of street samples for fast on-site screening of cocaine in seized drug powders |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemical science |
Abbreviated Journal |
Chem Sci |
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Volume |
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Issue |
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Pages |
1-7 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
We report on a wearable fingertip sensor for on-the-spot identification of cocaine and its cutting agents in street samples. Traditionally, on-site screening is performed by means of colour tests which are difficult to interpret and lack selectivity. By presenting the distinct voltammetric response of cocaine, cutting agents, binary mixtures of cocaine and street samples in solution and powder street samples, we were able to elucidate the electrochemical fingerprint of all these compounds. The new electrochemical concept holds considerable promise as an on-site screening method. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000371021900094 |
Publication Date |
2016-01-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-6520 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.668 |
Times cited |
37 |
Open Access |
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Notes |
; The authors acknowledge BELSPO for funding the APTADRU project (BR/314/PI/ APTADRU). ; |
Approved |
Most recent IF: 8.668 |
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Call Number |
UA @ admin @ c:irua:130404 |
Serial |
5591 |
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| Permanent link to this record |
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Author |
Pauwels, D.; Hereijgers, J.; Verhulst, K.; De Wael, K.; Breugelmans, T. |
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Title |
Investigation of the electrosynthetic pathway of the aldol condensation of acetone |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
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Volume |
289 |
Issue |
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Pages |
554-561 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
The potential-controlled electrochemical aldol condensation of acetone to diacetone alcohol in a standard batch electrolysis set-up was studied in this work. It is confirmed that the reaction proceeds at the cathode and that, contrary to what is mentioned in earlier literature, water in the electrolyte has a disadvantageous effect on the reaction. Similar to the chemical reaction, the electrochemical reaction reaches a maximum yield when the equilibrium is reached. Separating the anode and cathode prevents cross-over and degradation of products, leading to a higher yield. Starting with pure acetone and support electrolyte, it was possible to obtain a diacetone alcohol concentration of 15 m% after two hours electrolysis in a divided set-up with a platinum electrode at -2.5 V. The concentration gradient throughout the electrolysis follows an exponential curve up to its equilibrium concentration. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Language |
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Wos |
000371559900061 |
Publication Date |
2016-01-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1385-8947; 1873-3212 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.216 |
Times cited |
6 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 6.216 |
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Call Number |
UA @ admin @ c:irua:130396 |
Serial |
5675 |
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| Permanent link to this record |
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Author |
Ayalew, E.; Janssens, K.; De Wael, K. |
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Title |
Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
88 |
Issue |
3 |
Pages |
1564-1569 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art in order to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment, that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. To demonstrate its photoactivity, an electrochemical setup with minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor which is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of the degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experi-mentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4 modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded since the PbO reacts further to form hydrocerussite. Therefore the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process. |
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Corporate Author |
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Place of Publication |
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Wos |
000369471100014 |
Publication Date |
2015-12-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
9 |
Open Access |
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Notes |
; The authors acknowledge Sanne Aerts from the Laboratory of Adsorption and Catalysis (LADCA) of the University of Antwerp for her help with the UV-vis-DR. Financial support from the SOLARPAINT BOF-GOA project (University of Antwerp Research Council) is acknowledged. The authors are also indebted to F. Vanmeert for performing the XRD measurements. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:129963 |
Serial |
5888 |
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Author |
Sóti, V.; Jacquet, N.; Apers, S.; Richel, A.; Lenaerts, S.; Cornet, I. |
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Title |
Monitoring the laccase reaction of vanillin and poplar hydrolysate |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Journal of chemical technology and biotechnology |
Abbreviated Journal |
J Chem Technol Biot |
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Volume |
91 |
Issue |
6 |
Pages |
1914-1922 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Biochemical Wastewater Valorization & Engineering (BioWaVE) |
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Abstract |
BACKGROUND Laccase is an intensively researched enzyme for industrial use. Except for decolorisation measurements, HPLC analysis is the conventional method for monitoring the phenolic removal during laccase enzyme reaction. This paper reports an investigation of the continuous UV absorbance follow-up of the laccase reaction with steam pretreated poplar hydrolysate. RESULTS Vanillin was used as a model substrate and lignocellulose xylose rich fraction (XRF) as a biologically complex substrate for laccase detoxification. The reaction was followed by HPLC-UV as well as by UV spectrometric measurements. Results suggest that the reaction can be successfully monitored by measuring the change of UV absorbance at 280 nm, without previous compound separation. In case of XRF experiments the spectrophotometric follow-up is especially useful, as HPLC analysis takes a long time and provides less information than in case of single substrates. The method seems to be suitable for optimization and process control. CONCLUSION The obtained results can help to construct a fast, easy and straightforward monitoring system for laccase-phenolic substrate reactions. |
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Place of Publication |
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Wos |
000375768300040 |
Publication Date |
2015-07-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0268-2575; 1097-4660 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.135 |
Times cited |
3 |
Open Access |
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Notes |
; This research is financed by the University of Antwerp (project number 15 FA100 002). ; |
Approved |
Most recent IF: 3.135 |
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Call Number |
UA @ admin @ c:irua:127694 |
Serial |
5972 |
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Author |
Qurashi, A.; Rather, J.A.; Yamazaki, T.; Sohail, M.; De Wael, K.; Merzougui, B.; Hakeem, A.S. |
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Title |
Swift electrochemical detection of paraben an endocrine disruptor by In2O3 nanobricks |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
221 |
Issue |
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Pages |
167-171 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Novel indium oxide (In2O3) nanobricks have been prepared by template-less and surfactant-free hydrothermal synthesis method and were characterized by X-ray diffraction (XRD), Raman spectroscopy, photoluminescence (PL) spectroscopy and field emission scanning electronic microscopy (FESEM). The synthesized In2O3 nanobricks were successfully immobilized on the surface of glassy carbon electrode for the detection of Parabens (butylparaben). Owing to the unique structure and intriguing properties of these In2O3 nanobricks, the nanostructured thin-film electrode has shown an obvious electrocatalytic activity for the detection of butylparaben (BP). The detection limit (LOD) was estimated as 3 s/m and the sensitivity (LOQ) was calculated as 10 s/m and were found to be 0.08 μM and 0.26 μA μM−1 cm−2 respectively. This sensor showed high sensitivity compared with the reported electrochemical sensors for the detection of BP. The fabricated sensor was successfully applied for the detection of butyl paraben in real cosmetic samples with good recovery ranging from 96.0 to 100.3%. |
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Place of Publication |
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Wos |
000362918100021 |
Publication Date |
2015-06-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
11 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 5.401; 2015 IF: 4.097 |
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Call Number |
UA @ admin @ c:irua:127463 |
Serial |
5859 |
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Author |
Ranjbari, E.; Hadjmohammadi, M.R.; Kiekens, F.; De Wael, K. |
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Title |
Mixed hemi/ad-micelle sodium dodecyl sulfate-coated magnetic iron oxide nanoparticles for the efficient removal and trace determination of rhodamine-B and rhodamine-6G |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
87 |
Issue |
15 |
Pages |
7894-7901 |
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Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Mixed hemi/ad-micelle sodium dodecyl sulfate (SDS)-coated magnetic iron oxide nanoparticles (MHAMS-MIONPs) were used as an efficient adsorbent for both removal and preconcentration of two important carcinogenic xanthine dyes named rhodamine-B (RB) and rhodamine-6G (RG). To gain insight in the configuration of SDS molecules on the surface of MIONPs, zeta potential measurements were performed in different [SDS]/[MIONP] ratios. Zeta potential data indicated that mixed hemi/ad-micelle MHAM was formed in [SDS]/[MIONP] ratios over the range of 1.1 to 7.3. Parameters affecting the adsorption of dyes were optimized as removal efficiency by one variable at-a-time and response surface methodology; the obtained removal efficiencies were ∼100%. Adsorption kinetic and equilibrium studies, under the optimum condition (pH = 2; amount of MIONPs = 87.15 mg; [SDS]/[MIONP] ratio = 2.9), showed that adsorption of both dyes are based on the pseudo-second-order and the Langmuir isotherm models, respectively. The maximum adsorption capacities for RB and RG were 385 and 323 mg g1, respectively. MHAMS-MIONPs were also applied for extraction of RB and RG. Under optimum conditions (pH = 2; amount of damped MHAMS-MIONPs = 90 mg; eluent solvent volume = 2.6 mL of 3% acetic acid in acetonitrile), extraction recoveries for 0.5 mg L1 of RB and RG were 98% and 99%, with preconcentration factors of 327 and 330, respectively. Limit of detection obtained for rhodamine dyes were <0.7 ng mL1. Finally, MHAMS-MIONPs were successfully applied for both removal and trace determination of RB and RG in environmental and wastewater samples. |
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Wos |
000359277900056 |
Publication Date |
2015-07-08 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
36 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 6.32; 2015 IF: 5.636 |
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Call Number |
UA @ admin @ c:irua:126583 |
Serial |
5730 |
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Author |
Bertrand, L.; Schoeeder, S.; Anglos, D.; Breese, M.B.H.; Janssens, K.; Moini, M.; Simon, A. |
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Title |
Mitigation strategies for radiation damage in the analysis of ancient materials |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Trends in analytical chemistry |
Abbreviated Journal |
Trac-Trend Anal Chem |
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Volume |
66 |
Issue |
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Pages |
128-145 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The study of materials in cultural heritage artifacts and micro-samples benefits from diagnostic techniques based on intense radiation sources, such as synchrotrons, ion-beam accelerators and lasers. While most of the corresponding techniques are classified as non-destructive, investigation with photons or charged particles entails a number of fundamental processes that may induce changes in materials. These changes depend on irradiation parameters, properties of materials and environmental factors. In some cases, radiation-induced damage may be detected by visual inspection. When it is not, irradiation may still lead to atomic and molecular changes resulting in immediate or delayed alteration and bias of future analyses. Here we review the effects of radiation reported on a variety of cultural heritage materials and describe the usual practice for assessing short-term and long-term effects. This review aims to raise awareness and encourage subsequent research activities to limit radiation side effects. |
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Wos |
000352248200020 |
Publication Date |
2014-12-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0165-9936 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.442 |
Times cited |
35 |
Open Access |
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Notes |
; We wish to acknowledge the support of this initiative by the International Atomic Energy Agency. We gratefully thank Professor Manfred Schreiner of the Institute of Natural Sciences and Technology in the Arts (Akademie den bildenden Kunst, Vienna, Austria) for helpful discussions and insights on this work. We thank all colleagues who accepted to have their work reproduced in this review. IPANEMA at Synchrotron SOLEIL, the Hungarian Academy of Science and IESL-FORTH were supported within the Research Infrastructure program CHARISMA of the 7th Framework Programme of the EU (Grant Agreement no. 228330). MM's contribution is based upon work supported by the National Science Foundation under Grant numbers CHE 1241672 and CHE 1440849. We thank Chris McGlinchey and Lauren Klein (Museum of Modern Art, New York, USA) for their critical rereading of the manuscript. ; |
Approved |
Most recent IF: 8.442; 2015 IF: 6.472 |
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Call Number |
UA @ admin @ c:irua:124627 |
Serial |
5729 |
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Author |
Vanmeert, F.; van der Snickt, G.; Janssens, K. |
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Title |
Plumbonacrite identified by X-ray powder diffraction tomography as a missing link during degradation of red lead in a Van Gogh painting |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
54 |
Issue |
12 |
Pages |
3607-3610 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Red lead, a semiconductor pigment used by artists since antiquity, is known to undergo several discoloration phenomena. These transformations are either described as darkening of the pigment caused by the formation of either plattnerite (β-PbO2) or galena (PbS) or as whitening by which red lead is converted into anglesite (PbSO4) or (hydro)cerussite (2 PbCO3⋅Pb(OH)2; PbCO3). X-ray powder diffraction tomography, a powerful analytical method that allows visualization of the internal distribution of different crystalline compounds in complex samples, was used to investigate a microscopic paint sample from a Van Gogh painting. A very rare lead mineral, plumbonacrite (3 PbCO3⋅ Pb(OH)2⋅PbO), was revealed to be present. This is the first reported occurrence of this compound in a painting dating from before the mid 20th century. It constitutes the missing link between on the one hand the photoinduced reduction of red lead and on the other hand (hydro)cerussite, and thus sheds new light on the whitening of red lead. |
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Wos |
000351178300008 |
Publication Date |
2015-02-20 |
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ISSN |
1433-7851; 0570-0833 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
24 |
Open Access |
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Notes |
; The authors acknowledge L. Van der Loeff and M. Leeuwestein (Kroller-Muller Museum) for providing the paint sample. We thank Dr. J. Jaroszewicz (WUT) for performing the CT measurements. This research was carried out at the light source PETRA III at DESY, a member of the Helmholtz Association (HGF). We thank Dr. G. Falkenberg and the members of his team for their assistance in using beam line P06. We acknowledge financial support from the University of Antwerp GOA projects “XANES meets EELS” and “SOLARPaint”, as well as from BELSPO (Brussels) Project S2-ART and FWO (Brussels) project “ESRF-Dubble”. ; |
Approved |
Most recent IF: 11.994; 2015 IF: 11.261 |
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Call Number |
UA @ admin @ c:irua:124620 |
Serial |
5774 |
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Author |
Monico, L.; Janssens, K.; Vanmeert, F.; Cotte, M.; Brunetti, B.G.; van der Snickt, G.; Leeuwestein, M.; Plisson, J.S.; Menu, M.; Miliani, C. |
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Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : part 5 : effects of nonoriginal surface coatings into the nature and distribution of chromium and sulfur species in chrome yellow paints |
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A1 Journal article |
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Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
86 |
Issue |
21 |
Pages |
10804-10811 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The darkening of lead chromate yellow pigments, caused by a reduction of the chromate ions to Cr(III) compounds, is known to affect the appearance of several paintings by Vincent van Gogh. In previous papers of this series, we demonstrated that the darkening is activated by light and depends on the chemical composition and crystalline structure of the pigments. In this work, the results of Part 2 are extended and complemented with a new study aimed at deepening the knowledge of the nature and distribution of Cr and S species at the interface between the chrome yellow paint and the nonoriginal coating layer. For this purpose, three microsamples from two varnished paintings by Van Gogh and a waxed low relief by Gauguin (all originally uncoated) have been examined. Because nonoriginal coatings are often present in artwork by Van Gogh and contemporaries, the understanding of whether or not their application has influenced the morphological and/or physicochemical properties of the chrome yellow paint underneath is relevant in view of the conservation of these masterpieces. In all the samples studied, microscopic X-ray fluorescence (mu-XRF) and X-ray absorption near edge structure (mu-XANES) investigations showed that Cr(III)-based alteration products are present in the form of grains inside the coating (generally enriched of S species) and also homogeneously widespread at the paint surface. The distribution of Cr(III) species may be explained by the mechanical friction caused by the coating application by brush that picked up and redistributed the superficial Cr compounds, likely already present in the reduced state as result of the photodegradation process. The analysis of the XANES profiles allowed us to obtain new insights into the nature of the Cr(III) alteration products, that were identified as sulfate-, oxide-, organo-metal-, and chloride-based compounds. Building upon the knowledge acquired through the examination of original paint samples and from the investigation of aged model paints in the last Part 4 paper, in this study we aim to characterize a possible relation between the chemical composition of the coating and the chrome yellow degradation pathways by studying photochemically aged model samples covered with a dammar varnish contaminated with sulfide and sulfate salts. Cr speciation results did not show any evidence of the active role of the varnish and added S species on the reduction process of chrome yellows. |
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Wos |
000344510200043 |
Publication Date |
2014-10-10 |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
25 |
Open Access |
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Notes |
; This research was supported by the Italian projects PRIN (SICH) and PON (ITACHA). The text also presents results from Interuniversity Attraction Poles Programme Belgian Science Policy (S2-ART project S4DA), GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. ESRF is acknowledged for the grants received (experiments EC-799 and EC-1051). L.M. acknowledges the CNR for the financial support received in the framework of the Short Term Mobility Programme 2013. Thanks are expressed to Ella Hendriks (Van Gogh Museum, Amsterdam) and Muriel Geldof (Cultural Heritage Agency of The Netherlands) for selecting and sharing the information on the cross-section taken from Bank of the Seine. All the staff of the Van Gogh Museum, the Kroller-Muller Museum, and the Musee d'Orsay are acknowledged for the agreeable cooperation. ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
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Call Number |
UA @ admin @ c:irua:122100 |
Serial |
5570 |
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Author |
Buczyńska, A.J.; Geypens, B.; Van Grieken, R.; De Wael, K. |
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Title |
Optimization of sample clean-up for the GC-C-IRMS and GC-IT-MS analysis of PAHs from air particulate matter |
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A1 Journal article |
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Year |
2015 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
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Volume |
119 |
Issue |
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83-92 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The optimization of sample clean-up for the analysis of air particulate matter PAHs stable carbon isotope ratio using Solid Phase Extraction (SPE) cartridges is described in this paper. Various adsorbents, such as silica gel, alumina, florisil, commercially available for sample purification were compared. Best performance for the clean-up of 24-h air particulate matter samples was obtained with activated silica-gel columns in terms of selectivity and reproducibility. One step clean-up was optimized for concentration determination and in case of co-elutions, a second step was additionally used for carbon isotope ratio analysis. The method was subsequently validated with standard reference material and was checked for carbon isotope fractionation artefacts. No significant differences in δ13C values were found for unprocessed solutions of PAHs and solution subjected to the extraction and purification procedure. The procedure was tested on air particulate matter samples collected in three different locations in Belgium. Statistically significant differences in carbon isotope ratio of PAHs between Borgerhout location and Zelzate or Gent were noticed, confirming the differences in distribution and diagnostic ratios found during the concentration analyses and different PAH sources in these locations. The results, therefore, seem very promising for the use of δ13C of PAHs as an additional information helpful in source identification of these pollutants |
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Wos |
000348957800013 |
Publication Date |
2014-11-01 |
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ISSN |
0026-265x; 0026-265x |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.034 |
Times cited |
7 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.034; 2015 IF: 2.746 |
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Call Number |
UA @ admin @ c:irua:120641 |
Serial |
5759 |
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Author |
Hamidi-Asl, E.; Daems, D.; De Wael, K.; Van Camp, G.; Nagels, L.J. |
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Title |
Concentration related response potentiometric titrations to study the interaction of small molecules with large biomolecules |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
86 |
Issue |
24 |
Pages |
12243-12249 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In the present article, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small molecule interactions is reported. This approach is fast, sensitive, reproducible and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed to a concentration related signal over the entire concentration interval, also at low concentrations, where the mV (y-axis) versus logcanalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, the Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anti-cocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis (4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using SPR. The potentiometric titration approach called Concentration related Response Potentiometry, is used to study molecular interaction for 7 macromolecular target molecules and 4 small molecule ligands. |
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Wos |
000346683900048 |
Publication Date |
2014-11-13 |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
10 |
Open Access |
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Notes |
; Financial support for this work was provided by the University of Antwerp by granting L.J.N., K.D.W, G.V.C., and Ronny Blust a POC interdisciplinary research project. ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
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Call Number |
UA @ admin @ c:irua:120164 |
Serial |
5548 |
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