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Records |
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Author |
De Meyer, S.; Vanmeert, F.; Vertongen, R.; van Loon, A.; Gonzalez, V.; van der Snickt, G.; Vandivere, A.; Janssens, K. |
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Title |
Imaging secondary reaction products at the surface of Vermeer's Girl with the Pearl Earring by means of macroscopic X-ray powder diffraction scanning |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Heritage science |
Abbreviated Journal |
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| |
Volume |
7 |
Issue |
1 |
Pages |
67 |
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| |
Keywords |
A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract  |
The use of non-invasive macroscopic imaging techniques is becoming more prevalent in the field of cultural heritage, especially to avoid invasive procedures that damage valuable artworks. For this purpose, an X-ray powder diffraction scanner (MA-XRPD) capable of visualising crystalline compounds in a highly specific manner was recently developed. Many inorganic pigments present in paintings fall into this category of materials. In this study, the 17th century oil painting Girl with a Pearl Earring (c. 1665) by Johannes Vermeer was analysed with a combination of transmission and reflection mode MA-XRPD. By employing this scanner in reflection mode, the relative sensitivity for compounds that are present at the paint surface could be increased, establishing it as a highly relevant technique for investigating the degradation processes that are ongoing at paint surfaces. Many of the original pigments employed by Vermeer could be identified, along with four secondary alteration products: gypsum (CaSO4 center dot 2H(2)O), anglesite (PbSO4), palmierite (K2Pb(SO4)(2)) and weddellite (CaC2O4 center dot 2H(2)O). The formation of gypsum was linked to the presence of chalk in the upper glaze layer while the formation of palmierite and weddellite is driven by the presence of lake pigments (and their substrates). In this manner, MA-XRPD can also be used to pinpoint locations relevant for sampling and synchrotron mu-XRPD analysis, which provides information on the microscopic make-up of the paint. A paint cross-section taken from an area rich in palmierite was analysed with synchrotron mu-XRPD, which confirmed the presence of this secondary compound at the interface of the upper paint layer with the ground layer as well as the presence of anglesite in the ground layer. The capacity of MA-XRPD to identify and chart secondary alteration products in a non-invasive manner has only very recently been demonstrated and makes it a highly relevant technique for the assessment of the chemical condition of works of art. |
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Editor |
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Wos |
000484938100001 |
Publication Date |
2019-09-08 |
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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 |
2050-7445 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
5 |
Open Access |
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Notes |
; The authors would like to thank Interreg Vlaanderen-Nederland for funding to help develop the MA-rXRPD scanner. This project was made possible with support from the Johan Maurits Compagnie Foundation. This study was supported by Interreg and CALIPSOplus (Grant 730872). ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:162801 |
Serial |
5653 |
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| Permanent link to this record |
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Author |
Vandersteen, G.; Schneidewind, U.; Anibas, C.; Schmidt, C.; Seuntjens, P.; Batelaan, O. |
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Title |
Determining groundwater-surface water exchange from temperature-time series : combining a local polynomial method with a maximum likelihood estimator |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Water resources research |
Abbreviated Journal |
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| |
Volume |
51 |
Issue |
2 |
Pages |
922-939 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The use of temperature-time series measured in streambed sediments as input to coupled water flow and heat transport models has become standard when quantifying vertical groundwater-surface water exchange fluxes. We develop a novel methodology, called LPML, to estimate the parameters for 1-D water flow and heat transport by combining a local polynomial (LP) signal processing technique with a maximum likelihood (ML) estimator. The LP method is used to estimate the frequency response functions (FRFs) and their uncertainties between the streambed top and several locations within the streambed from measured temperature-time series data. Additionally, we obtain the analytical expression of the FRFs assuming a pure sinusoidal input. The estimated and analytical FRFs are used in an ML estimator to deduce vertical groundwater-surface water exchange flux and its uncertainty as well as information regarding model quality. The LPML method is tested and verified with the heat transport models STRIVE and VFLUX. We demonstrate that the LPML method can correctly reproduce a priori known fluxes and thermal conductivities and also show that the LPML method can estimate averaged and time-variable fluxes from periodic and nonperiodic temperature records. The LPML method allows for a fast computation of exchange fluxes as well as model and parameter uncertainties from many temperature sensors. Moreover, it can utilize a broad frequency spectrum beyond the diel signal commonly used for flux calculations. |
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Wos |
000351401200009 |
Publication Date |
2014-12-31 |
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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 |
0043-1397; 0043-137x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:125492 |
Serial |
7797 |
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Author |
Jain, R.; Rather, J.A.; Dwivedi, A.; Vikas |
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Title |
Highly sensitive and selective voltammetric sensor fullerene modified glassy carbon electrode for determination of cefitizoxime in solubilized system |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Electroanalysis |
Abbreviated Journal |
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| |
Volume |
22 |
Issue |
21 |
Pages |
2600-2606 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The usefulness of fullerene modified glassy carbon electrode in mediating the reduction of cefitizoxime in solubilized system has been demonstrated. Due to the unique structure and extraordinary properties, fullerene shows higher catalytic efficiency towards cefitizoxime reduction. The kinetic parameters, electron transfer coefficient (α) and rate constant (K0) across the modified electrode are 0.37 and 0.1081/s respectively. The proposed square-wave voltammetric method is linear over the concentration range 1.210.3 µg/mL. The limit of detection (LOD) is found 0.27 ng/mL. High sensitivity and selectivity together with low detection limit of the electrode response make it suitable for the determination of cefitizoxime. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000284052900015 |
Publication Date |
2010-10-04 |
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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 |
1040-0397 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:98690 |
Serial |
8042 |
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| Permanent link to this record |
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Author |
Nguyen, H.L.; Braun, M.; Szaloki, I.; Baeyens, W.; Van Grieken, R.; Leermakers, M. |
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Title |
Tracing the metal pollution history of the Tisza River through the analysis of a sediment depth profile |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Water, air and soil pollution |
Abbreviated Journal |
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| |
Volume |
200 |
Issue |
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Pages |
119-132 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The vertical profiles of 20 major and trace metals were investigated along a 180-cm-long sediment core, which was sampled at Kiss-Janosne-Holt Tisza, an oxbow lake located in the upper part of the Tisza River in Hungary. The vertical profiles showed sharp peaks at different depths, reflecting historical pollution events and unusual changes of river water characteristics. Five different groups of metals, containing metals which were strongly correlated and showing a similar behaviour, could be distinguished by factor analysis. Six areas, with variable degrees and types of contamination, were classified in the sediment core with cluster analysis. The most polluted sections were found in the upper 50-cm part (significantly contaminated by Cu, Zn, Pb, Cd and Hg) and the deeper 100120-cm part (characterised by high concentrations of metals associated with mining activities, such as Fe and Mn, as well as Cu, Zn and Pb). In recent years, important pollution events, such as the one which took place in March of 2000, were the reason for pollution of the upper sediment layers, whereas mining activities during the last century were responsible for the pollution of the deeper core sections. |
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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 |
000266487700012 |
Publication Date |
2008-10-29 |
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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 |
0049-6979; 1573-2932 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:77257 |
Serial |
8695 |
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| Permanent link to this record |
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Author |
Sebhatu, K.T.; Taheri, F.; Berhanu, T.; Maertens, M.; Van Passel, S.; D'Haese, M. |
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Title |
Beyond focus : exploring variability of service provision of agricultural cooperatives |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Annals of public and cooperative economics |
Abbreviated Journal |
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Volume |
92 |
Issue |
2 |
Pages |
207-231 |
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Keywords |
A1 Journal article; Economics; Engineering Management (ENM) |
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Abstract |
The wide array of services provided by agricultural cooperatives for their members is often not considered in academic studies. Addressing this gap in the literature, our paper explores the wide array of services provided by agricultural cooperatives and how these extend beyond those they were initially intended to provide. We study the extent and characteristics of service portfolios from 511 agricultural cooperatives in the Tigray region of Ethiopia. Results from two-limit Tobit models confirm that government and NGO-initiated cooperatives have a wide service portfolio compared to member-initiated cooperatives. In many of the studied cooperatives, the services they provide and their portfolios are more diverse than expected. Cooperatives seem to go beyond their focal areas of intervention. Also, those cooperatives that are more outward-oriented and where the chair has contact with other cooperatives or businesses, have a wider service portfolio. These results may help to explain the mixed findings on the impact of cooperative membership. |
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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 |
000583855500001 |
Publication Date |
2020-10-27 |
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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 |
1370-4788; 1467-8292 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:173574 |
Serial |
6916 |
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| Permanent link to this record |
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Author |
Horemans, B.; Schalm, O.; De Wael, K.; Cardell, C.; Van Grieken, R. |
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Title |
Atmospheric composition and micro-climate in the Alhambra monument, Granada (Spain), in the context of preventive conservation |
Type |
P1 Proceeding |
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Year |
2012 |
Publication |
IOP conference series : materials science and engineering |
Abbreviated Journal |
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Volume |
37 |
Issue |
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Pages |
012002-12008 |
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Keywords |
P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The world famous Alhambra monument in Granada, Southern Spain, listed as UNESCO world cultural heritage since 1984, represents probably the most beautiful example of Islamic art and architecture from the Middle Ages in Europe. It is visited by ca. 2 million people annually. Granada is situated in a natural basin, surrounded by mountains with altitudes up to 3500 m. Due to this topography and the prevailing low wind speeds, pollution-derived and especially traffic-derived particulate matter often accumulates in the urban air. In order to evaluate the potential conservation risks from the surrounding air, the atmospheric composition in the Alhambra monument was evaluated. Indoor temperature and relative humidity fluctuations were evaluated for their potential degenerative effects. Furthermore, the atmospheric composition in the Alhambra was analyzed in terms of inorganic gases (NO2, SO2, O3, and NH3) and black carbon. It was found that the open architecture protected the indoor environments from developing a potentially harmful microclimate, such as the build-up of humidity resulting from the huge number of daily tourists. On the downside, the strong ventilation made the indoor air hardly different from outdoor air, as characterized by strong diurnal temperature and relative humidity gradients and high traffic-derived pollutant levels. |
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Wos |
000307662000002 |
Publication Date |
2012-07-16 |
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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 |
1757-8981; 1757-899x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:100112 |
Serial |
5484 |
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Author |
Van Grieken, R.E.; Johansson, T.B.; Winchester, J.W.; Odom, L. |
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Title |
Micro-determination of zirconium-hafnium ratios in zircons by proton induced X-ray emission |
Type |
A3 Journal article |
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Year |
1975 |
Publication |
Fresenius' Zeitschrift für analytische Chemie |
Abbreviated Journal |
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Volume |
275 |
Issue |
5 |
Pages |
343-348 |
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Keywords |
A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The zirconium/hafnium ratios of zircons are determined using proton induced X-ray emission. Submilligram samples, imbedded in a starch layer and deposited on a 50 μg/cm2 polystyrene carrier, are irradiated for 1020 min with a 5 nA beam of 3.7 MeV protons, while the Hf-Lβ and Zr-Kα X-rays are counted with a Si(Li) detector. The standard deviation per analysis is in the 36 % range. Only few interferences are possible. To eliminate errors due to absorption effects the zircon layer thickness should be above 40 μm or reproducibly thin samples should be employed. Measuring the Hf-Lβ/Hf-Lα ratio for samples and standards might provide a practical check for the absence of absorption errors. The sensitivity is so favourable that, in practice, the minimal sample size is only limited by the minimal amount that can be handled properly. |
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Place of Publication |
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Language |
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Wos |
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Publication Date |
2004-11-11 |
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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 |
0016-1152 |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:116636 |
Serial |
8231 |
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Author |
Callebaut, D.K.; Makarovska, Y. |
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Title |
On the relationship between current and magnetic field in ring-filaments |
Type |
P1 Proceeding |
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Year |
1998 |
Publication |
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Abbreviated Journal |
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Volume |
150 |
Issue |
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Pages |
111-114
T2 - IAU Colloquium 167 on New Perspective |
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Keywords |
P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
There is a type of filament that forms dosed contours encircling regions of one polarity of magnetic field, while the surrounding region has the opposite polarity One distribution of ring-filaments has sizes 2R = 40,000 to 160,000 km with the maximum around 100,000 km; the other distribution (with filaments and filament channels) has bigger sizes, with a maximum around 300,000 km. At low and mid latitudes the radial component B-rs (radial for the Sun) in the region outlined by filaments varies from 50 to 100 gauss, while the longitudinal component B-phi varies from 10 to 30 gauss. The total current inside the filament is 10(10) – 10(11) A, the ratio R/a approximate to 5 to 10, the magnetic flux crossing the surface is approximate to 10(21) – 10(22) MX; th, magnetic energy is approximate to 10(29) – 10(31) erg. Polar ring-filaments at latitudes 60 degrees-80 degrees are related to the polar magnetic field reversal and the quasi-flare processes at the poles during the field reversal. Correlation between B-rs and B-phi for the polar filament bands cannot be satisfactorily explained. A theoretical model using the conservation laws is used to study the relations between the various fields, currents, etc, of shrinking polar ring-filaments and their evolution. According to this theory ring-filaments should rise higher above the photosphere when shrinking. However, observations show that the height lowers. Presumably the discrepancy is due to the lack of dissipation in the model. |
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Wos |
000076565100020 |
Publication Date |
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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 |
1-886733-70-8 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:95844 |
Serial |
8333 |
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Author |
Moro, G.; Foumthuim, C.J.D.; Spinaci, M.; Martini, E.; Cimino, D.; Balliana, E.; Lieberzeit, P.; Romano, F.; Giacometti, A.; Campos, R.; De Wael, K.; Moretto, L.M. |
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Title |
How perfluoroalkyl substances modify fluorinated self-assembled monolayer architectures : an electrochemical and computational study |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Analytica chimica acta |
Abbreviated Journal |
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Volume |
1204 |
Issue |
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Pages |
339740-12 |
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Keywords |
A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
There is an urgent need for sensing strategies to screen perfluoroalkyl substances (PFAS) in aqueous matrices. These strategies must be applicable in large-scale monitoring plans to face the ubiquitous use of PFAS, their wide global spread, and their fast evolution towards short-chain, branched molecules. To this aim, the changes in fluorinated self-assembled monolayers (SAM) with different architectures (pinholes/defects-free and with randomized pinholes/defects) were studied upon exposure to both long and short-chain PFAS. The applicability of fluorinated SAM in PFAS sensing was evaluated. Changes in the SAM structures were characterised combining electrochemical impedance spectroscopy and voltam-metric techniques. The experimental data interpretation was supported by molecular dynamics simu-lations to gain a more in-depth understanding of the interaction mechanisms involved. Pinhole/defect-free fluorinated SAM were found to be applicable to long-chain PFAS screening within switch-on sensing strategy, while a switch-off sensing strategy was reported for screening of both short/long-chain PFAS. These strategies confirmed the possibility to play on fluorophilic interactions when designing PFAS screening methods.(c) 2022 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Place of Publication |
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Wos |
000789493000010 |
Publication Date |
2022-03-17 |
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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 |
0003-2670; 1873-4324 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:188658 |
Serial |
8880 |
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Author |
Verstraete, W.; Clauwaert, P.; Vlaeminck, S.E. |
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Title |
Used water and nutrients : recovery perspectives in a 'panta rhei' context |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Bioresource technology |
Abbreviated Journal |
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Volume |
215 |
Issue |
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Pages |
199-208 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
There is an urgent need to secure global supplies in safe water and proteinaceous food in an eco-sustainable manner, as manifested from tensions in the nexus Nutrients-Energy-Water-Environment-Land. This paper is concept based and provides solutions based on resource recovery from municipal and industrial wastewater and from manure. A set of decisive factors is reviewed facilitating an attractive business case. Our key message is that a robust barrier must clear the recovered product from its original status. Besides refined inorganic fertilizers, a central role for five types of microbial protein is proposed. A resource cycling solution for the extremely confined environment of space habitation should serve as an incentive to assimilate a new user mindset. To achieve the ambitious goal of sustainable food security, the solutions suggested here need a broad implementation, hand in hand with minimizing losses along the entire fertilizer-feed-food-fork chain. (C) 2016 Elsevier Ltd. All rights reserved. |
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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 |
000377935100022 |
Publication Date |
2016-04-29 |
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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 |
0960-8524 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:134591 |
Serial |
8726 |
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| Permanent link to this record |
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Author |
Huang, W.; Su, X.; Ratkowsky, D.A.; Niklas, K.J.; Gielis, J.; Shi, P. |
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Title |
The scaling relationships of leaf biomass vs. leaf surface area of 12 bamboo species |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Global ecology and conservation |
Abbreviated Journal |
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Volume |
20 |
Issue |
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Pages |
e00793 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
There is convincing evidence for a scaling relationship between leaf dry weight (DW) and leaf surface area (A) for broad-leaved plants, and most estimates of the scaling exponent of DW vs. A are greater than unity. However, the scaling relationship of leaf fresh weight (FW) vs. A has been largely neglected. In the present study, we examined whether there is a statistically strong scaling relationship between FW and A and compared the goodness of fit to that of DW vs. A. Between 250 and 520 leaves from each of 12 bamboo species within 2 genera (Phyllostachys and Pleioblastus) were investigated. The reduced major axis regression protocols were used to determine scaling relationships. The fit for the linearized scaling relationship of FW vs. A was compared with that of DW vs. A using the coefficient of determination (i.e., r2). A stronger scaling relationship between FW and A than that between DW and A was observed for each of the 12 bamboo species investigated. Among the 12 species examined, five had significantly smaller scaling exponents of FW vs. A compared to those of DW vs. A; only one species had a scaling exponent of FW vs. A greater than that of DW vs. A. No significant difference between the two scaling exponents was observed for the remaining 6 species. Researchers conducting future studies might be well advised to consider the influence of leaf fresh weight when exploring the scaling relationships of foliar biomass allocation patterns. |
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Wos |
000498226800095 |
Publication Date |
2019-09-19 |
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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 |
2351-9894; 2351-9894 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:162954 |
Serial |
8497 |
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| Permanent link to this record |
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Author |
De Keyser, N.; van der Snickt, G.; Van Loon, A.; Legrand, S.; Wallert, A.; Janssens, K. |
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Title |
Jan Davidsz. de Heem (1606-1684): a technical examination of fruit and flower still lifes combining MA-XRF scanning, cross-section analysis and technical historical sources |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Heritage science |
Abbreviated Journal |
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Volume |
5 |
Issue |
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Pages |
38 |
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Keywords |
A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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| |
Abstract |
This article discusses the technical examination of five flower and fruit still life paintings by the seventeenth century artist Jan Davidsz. de Heem (1606-1684). The painter is known for his meticulously composed and finely detailed still life paintings and is a master in imitating the surface textures of various fruits, flowers, and objects. Macro X-ray fluorescence (MA-XRF) scanning experiments were supplemented with a study of paint cross-sections and contemporary art technical sources with the aim of reconstructing the complex build-up of the overall lay-in of the composition and individual subjects. MA-XRF provided information on the distribution of key chemical elements present in painting materials and made it possible to recapture evidence of the different phases in the artist's working methods: from the application of the ground layers, to De Heem's characteristic oval-shaped underpaintings, and finally, the superposition of multiple paint layers in the working up of the paintings. SEM-EDX analysis of a limited number of paint cross-sections complemented the chemical images with local and layer-specific information on the microscale, providing more accuracy on the layer sequence and enabling the study of elements with a low atomic number for which the non-invasive technique is less sensitive. The results from this technical examination were in addition compared with recipes and paint instructions, to obtain a better understanding of the relation between the general practice and actual painting technique of Jan Davidsz. de Heem. Ultimately, this combined approach uncovered new information on De Heem's artistic practice and demonstrated the complementarity of the methods. |
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Wos |
000410414000001 |
Publication Date |
2017-08-14 |
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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 |
2050-7445 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
5 |
Open Access |
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Notes |
; This work is an extension of the Master thesis in Conservation-restoration (University of Antwerp, 2015-2016) of Nouchka De Keyser. Thesis supervisors were Dr. Geert Van der Snickt (Cultural heritage scientist, AXES, UA) and Dr. Olivier Schalm (Research scientist, UA). This research was supported by the Baillet Latour fund. The authors gratefully acknowledge the involved institutes (Rijksmuseum, the Mauritshuis and KMSKA) for the opportunity to examine the still life paintings of Jan Davidsz. de Heem. A great thanks is therefore due to Petria Noble, Pieter Roelofs, Anna Krekeler, Susan Smelt, Robert Erdmann, Abbie Vandivere, Edwin Buijsen and Masayuki Hinoue. SEM-EDX measurements were performed by Katrien Keune, scientific researcher at the Rijksmuseum. ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:145628 |
Serial |
5681 |
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| Permanent link to this record |
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Author |
Marguí, E.; Van Grieken, R.; Fontàs, C.; Hidalgo, M.; Queralt, I. |
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Title |
Preconcentration methods for the analysis of liquid samples by X-ray fluorescence techniques |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Applied spectroscopy reviews |
Abbreviated Journal |
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Volume |
45 |
Issue |
3 |
Pages |
179-205 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
This article gives an overview of the state-of-the-art of multi-element and single-element preconcentration procedures prior to X-ray fluorescence (XRF) analysis of liquid samples. Many of these preconcentration methods were developed long ago and the purpose of this review is to present some new efficient variations of these methods and new techniques extending the possibilities of XRF for liquid solutions analysis. In addition, trends and future perspectives in this domain are also commented on and discussed in the last section of the review. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000277705800002 |
Publication Date |
2010-01-28 |
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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 |
0066-5541 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:82557 |
Serial |
8400 |
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| Permanent link to this record |
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Author |
Robberecht, H.; Van Grieken, R. |
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Title |
Selenium in environmental waters : determination, speciation and concentration levels |
Type |
A1 Journal article |
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Year |
1982 |
Publication |
Talanta : the international journal of pure and applied analytical chemistry |
Abbreviated Journal |
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Volume |
29 |
Issue |
10 |
Pages |
823-844 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
This article reviews the different methods used for the determination of selenium species in all types of environmental waters. Basic difficulties are discussed and the efficiency of the methods is explained in view of the sub-μg/1. concentration levels. Special attention is paid to preconcentration steps. Published data on speciation and concentration levels in various water samples are critically reviewed. |
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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 |
A1982PK22900004 |
Publication Date |
2002-07-25 |
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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 |
0039-9140; 1873-3573 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:113627 |
Serial |
8509 |
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| Permanent link to this record |
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Author |
Geldof, M.; Monico, L.; Johnson, D.H.; Miliani, C.; Romani, A.; Grazia, C.; Buti, D.; Brunetti, B.G.; Janssens, K.; Van der Snickt, G.; Vanmeert, F. |
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Title |
Methods and materials of the Amsterdam sunflowers |
Type |
H1 Book chapter |
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Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
85-123
T2 - Van Gogh’s Sunflowers illuminated – ar |
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Keywords |
H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
This chapter explains the materials and techniques employed in the Amsterdam Sunflowers, enabling a comparison with the London version described in chapter 3. Building upon the 2016 article published in the National Gallery Technical Bulletin, it incorporates the latest findings gained by computer-assisted methods used to characterize the canvas support, as well as in-situ campaigns of non-invasive investigation together with further analysis of microscopic paint samples. The chapter sequence follows the steps in Van Gogh's working practice. Starting with the canvas, automated analysis of the weave enables the provenance of the canvas to be traced back to a particular roll of linen ordered by Van Gogh. Combining technical evidence with knowledge of historical manufacturing techniques further allows us to reconstruct the way in which Van Gogh divided his canvas roll into pieces used for Sunflowers and other paintings. We go on to consider how, with the original painting at hand, he used charcoal to transfer the motif of the London Sunflowers onto his blank canvas. Despite careful planning of the composition, an adjustment was required late in the working process, when Van Gogh added a painted wooden strip to extend the background above the flower at the top edge of the canvas. The artist's process of working up the composition in paint is described, paying special attention to his use of colour. The pigments and pigment mixtures used in the Amsterdam Sunflowers have been comprehensively mapped and are compared with the London picture, with discussion of some similarities and differences that account for the distinctive colour scheme of each painting. This understanding of colour application in the Amsterdam Sunflowers lays the foundation for subsequent chapters that will go on to consider the impact of light-induced colour changes that have taken place over time, and the related need to define appropriate lighting guidelines for the future safe preservation of this painting and others made with similar materials (chapters 5 and 7). |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
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Publication Date |
2020-11-25 |
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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 |
|
ISBN |
978-94-6372-532-3 |
Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:190781 |
Serial |
8223 |
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| Permanent link to this record |
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Author |
Hendriks, E.; Geldof, M.; van den Berg, K.J.; Monico, L.; Miliani, C.; Moretti, P.; Iwanicka, M.; Targowski, P.; Megens, L.; de Groot, S.; van Keulen, H.; Janssens, K.; Vanmeert, F.; van der Snickt, G. |
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Title |
Conservation of the Amsterdam sunflowers : from past to future |
Type |
H1 Book chapter |
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Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
175-205
T2 - Van Gogh’s Sunflowers illuminated – a |
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Keywords |
H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
This chapter lays out a conservation timeline, from past to future, for the Amsterdam version of Van Gogh's Sunflowers. It starts by considering the restoration history of the painting in order to assess its current physical state, and looks ahead to formulate an appropriate strategy for future conservation treatment and display. Due attention is paid to the two recorded episodes of restoration performed in 1927 and 1961 by the Dutch restorer, Jan Cornelis Traas. Based on physical and chemical investigation of Sunflowers we attempt to reconstruct what these former treatments (which are barely documented) entailed and consider the repercussions for the present condition of the painting. The former interventions by Traas also serve as a benchmark to reflect on current choices made, highlighting the extent to which ideas and methodologies have continued to evolve over the past century as conservation has moved further away from being a singularly craft-based activity to become an established historical and scientific discipline underpinned by ethical guidelines. Jan Cornelis Traas (1898–1984) As mentioned, the two main recorded interventions to the Amsterdam Sunflowers may be associated with the Dutch restorer, Jan Cornelis Traas, who treated the picture in 1927, close to the start of his career, and again in 1961, shortly before he retired. Traas was the first restorer to be appointed at the Mauritshuis in The Hague where he worked from 1931 to 1962 and treated hundreds of paintings, including iconic masterpieces such as Girl with a Pearl Earring by Johannes Vermeer. Yet despite the magnitude and importance of his restoration oeuvre, J.C. Traas (as he is usually referred to in surviving documents), has remained somewhat obscure. He is shown here in the only known surviving photograph of him at work, shortly before he retired (fig. 7.1). Unlike his illustrious contemporaries, A. Martin de Wild (1899–1969) and Helmut Ruhemann (1891–1973), for example, Traas did not publish anything, he appears to have kept no records of his work and no personal archive is known. However, the study of some newly discovered historical documents, combined with physical examination of Sunflowers and a large number of other works he treated, allows us to recover an idea of his working practices and approaches viewed within the context of his day. |
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Wos |
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Publication Date |
2020-11-25 |
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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 |
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ISBN |
978-94-6372-532-3 |
Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:190780 |
Serial |
7727 |
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| Permanent link to this record |
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Author |
Monico, L.; Hendriks, E.; Geldof, M.; Miliani, C.; Janssens, K.; Brunetti, B.G.; Cotte, M.; Vanmeert, F.; Chieli, A.; Van der Snickt, G.; Romani, A.; Melo, M.J. |
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Title |
Chemical alteration and colour changes in the Amsterdam sunflowers |
Type |
H1 Book chapter |
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Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
125-158
T2 - Van Gogh’s Sunflowers illuminated – a |
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Keywords |
H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
This chapter provides a description of colour changes in the Amsterdam Sunflowers due to chemical alteration of pigments, with a focus on geranium lakes and chrome yellows. The brilliant and forceful colours of these and other late nineteenth-century synthetic materials offered artists such as Vincent van Gogh new means of artistic expression that exploited a range of contrasting hues and tints. However, geranium lakes have a strong tendency to fade and chrome yellows to darken under the influence of light. Van Gogh, like other artists of his day, was aware of this drawback, yet he continued to favour the use of both pigments up until his death in July 1890 due to the unparalleled effects they gave. In April 1888, Vincent wrote to his brother Theo: Van Gogh's use of unstable colours opens a series of questions regarding the extent to which colour change affects the way his paintings look today, as discussed here in relation to the Amsterdam Sunflowers. Furthermore, given the frequency with which geranium lakes and chrome yellows occur in Van Gogh's paintings of the period 1888–90 and the predominance of chrome yellows in Sunflowers, it becomes important to understand the factors that can drive these processes of deterioration in order to develop appropriate strategies for conserving the artist's works. |
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Wos |
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Publication Date |
2020-11-25 |
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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 |
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ISBN |
978-94-6372-532-3 |
Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:190779 |
Serial |
7640 |
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| Permanent link to this record |
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Author |
Stranger, M.; Potgieter-Vermaak, S.S.; Van Grieken, R. |
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Title |
Particulate matter and gaseous pollutants in residences in Antwerp, Belgium |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
The science of the total environment |
Abbreviated Journal |
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Volume |
407 |
Issue |
3 |
Pages |
1182-1192 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
This comprehensive study, a first in Flanders, Belgium, aimed at characterizing the residential indoor air quality of subgroups that took part in the European Community Respiratory Health Survey (ECRHS I1991 and ECHRS II1996) questionnaire-based asthma and related illnesses studies. This pilot study aimed at the evaluation of particulate matter and various inorganic gaseous compounds in residences in Antwerp. In addition personal exposure to the gaseous compounds of one individual per residence was assessed. The main objective was to obtain some base-line pollutant levels and compare these with studies performed in other cities, to estimate the indoor air quality in residences in Antwerp. Correlations between the various pollutant levels, indoor:outdoor ratios and the micro-environments of each residence were investigated. This paper presents results on indoor and ambient PM1, PM2.5 and PM10 mass concentrations, its elemental composition in terms of K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb, Al, Si, S and Cl and the water-soluble ionic concentrations in terms of SO42−, NO32−, Cl−, NH4+ K+, Ca2+. In addition, indoor, ambient and personal exposure levels of the gases NO2, SO2, and O3 were determined. Elevated indoor:outdoor ratios were found for NO2 in residences containing gas stoves. In smoker's houses increased PM concentrations of 58 and 43% were found for the fine and coarse fractions respectively. Contrary to the fact that all I/O ratios of the registered elements in each individual house were significantly correlated to each other, no correlation could be established between the I/O ratios of the different houses, thus indicating a unique micro-environment for each residence. Linear relationships between the particulate matter elemental composition, SO2 and O3 levels indoors and outdoors could be established. No linear relationships between indoor and outdoor NO2 and particulate mass concentrations were found. |
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Wos |
000262660800020 |
Publication Date |
2008-11-15 |
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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 |
0048-9697; 1879-1026 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:76002 |
Serial |
8361 |
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| Permanent link to this record |
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Author |
Alloul, A.; Ganigue, R.; Spiller, M.; Meerburg, F.; Cagnetta, C.; Rabaey, K.; Vlaeminck, S.E. |
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Title |
Capture-ferment-upgrade : a three-step approach for the valorization of sewage organics as commodities |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Environmental science and technology |
Abbreviated Journal |
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Volume |
52 |
Issue |
12 |
Pages |
6729-6742 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
This critical review outlines a roadmap for the conversion of chemical oxygen demand (COD) contained in sewage to commodities based on three-steps: capture COD as sludge, ferment it to volatile fatty acids (VFA), and upgrade VFA to products. The article analyzes the state-of-the-art of this three step approach and discusses the bottlenecks and challenges. The potential of this approach is illustrated for the European Union's 28 member states (EU-28) through Monte Carlo simulations. High-rate contact stabilization captures the highest amount of COD (66-86 g COD person equivalent(-1) day(-1) in 60% of the iterations). Combined with thermal hydrolysis, this would lead to a VFA-yield of 23-44 g COD person equivalent(-1) day(-1). Upgrading VFA generated by the EU-28 would allow, in 60% of the simulations, for a yearly production of 0.2-2.0 megatonnes of esters, 0.7-1.4 megatonnes of polyhydroxyalkanoates or 0.6-2.2 megatonnes of microbial protein substituting, respectively, 20-273%, 70-140% or 21-72% of their global counterparts (i.e., petrochemical-based esters, bioplastics or fishmeal). From these flows, we conclude that sewage has a strong potential as biorefinery feedstock, although research is needed to enhance capture, fermentation and upgrading efficiencies. These developments need to be supported by economic/environmental analyses and policies that incentivize a more sustainable management of our resources. |
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Place of Publication |
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Wos |
000436018900004 |
Publication Date |
2018-05-17 |
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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 |
0013-936x; 1520-5851 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:151968 |
Serial |
7574 |
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| Permanent link to this record |
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Author |
Cautaerts, N.; Lamm, S.; Stergar, E.; Pakarinen, J.; Yang, Y.; Hofer, C.; Schnitzer, R.; Felfer, P.; Verwerft, M.; Delville, R.; Schryvers, D. |
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Title |
Atom probe tomography data collection from DIN 1.4970 (15-15Ti) austenitic stainless steel irradiated with Fe ions |
Type |
Dataset |
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Year |
2020 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Dataset; Electron microscopy for materials research (EMAT) |
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Abstract |
This dataset comprises a large collection of atom probe tomography datasets collected from DIN 1.4970 alloy that was irradiated with Fe ions at different conditions. The DIN 1.4970 alloy is an austenitic stainless steel with 15 wt% Cr, 15 wt% Ni, a small addition of Ti. The full composition and characterization of our material can be found published elsewhere [1,2]. Some of our material was subjected to ageing heat treatments at different temperatures for different times. Small samples of our original material and aged material was irradiated at the Michigan Ion Beam Laboratory in 2017 with 4.5 MeV Fe ions up to 40 dpa at an average dose rate of 2×10−4 dpa/s. This was done at three different temperatures: 300, 450, and 600 ºC. Atom probe samples were made of the irradiated layers (approximately 1.5 micron deep) with focused ion beam and mounted on Microtip coupons. APT measurements took place on three CAMECA LEAP-HR systems located at CAES in Idaho Falls, USA (files beginning with R33), at Montanuniversität Leoben in Leoben, Austria (R21) and at Friedrich–Alexander University in Erlangen, Germany (R56). |
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; ; |
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Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:169127 |
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6454 |
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Skorikov, A.; Heyvaert, W.; Albrecht, W.; Pelt, D.M.; Bals, S. |
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Title |
EMAT Simulated 3D Nanoparticle Structures Dataset |
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2021 |
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Dataset; Electron microscopy for materials research (EMAT) |
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This dataset contains 1000 simulated nanoparticle-like 3D structures and noisy EDX-like elemental maps based on them. These data are intended to be used for quantitative analysis of data processing methods in (EDX) tomography of nanoparticles and training the data-driven approaches for these tasks. The dataset is structured as follows: voxel_data/clean 3D voxel grid representation of the simulated nanoparticles. Voxel intensities are adjusted so that the total intensity equals 103. All 3D structures have unique identifiers in 0..999 range. The data derived from a 3D structure preserves this unique identifier. sinograms/clean Tilt series of projection images obtained from the corresponding 3D structures over an angular range of -75..75 degrees with a tilt step of 10 degrees to simulate a typical tilt series used in EDX tomography. Total intensity in each projection image equals 103. sinograms/noisy Tilt series of projection images corrupted with Poisson noise and an additional spatially uniform background noise. projections/clean Projection images extracted from the clean tilt series at 0 degrees tilt angle. projections/noisy Projection images extracted from the noisy tilt series at 0 degrees tilt angle. images/clean Visualizations of the clean projections as PNG images with the intensity range adjusted to 0..255 images/noisy Visualizations of the noisy projections as PNG images with the intensity range adjusted to 0..255 |
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Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:180615 |
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6838 |
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Author |
Jannis, D.; Müller-Caspary, K.; Béché, A.; Oelsner, A.; Verbeeck, J. |
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Title |
Spectrocopic coincidence experiment in transmission electron microscopy |
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2019 |
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Dataset; Electron microscopy for materials research (EMAT) |
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This dataset contains individual EEL and EDX events where for every event (electron or X-ray), their energy and time of arrival is stored. The experiment was performed in a transmission electron microscope (Tecnai Osiris) at 200 keV. The material investigated is an Al-Mg-Si-Cu alloy. The 'full_dataset.mat' contains the full dataset and the 'subset.mat' has the first five frames of the full dataset. The attached 'EELS-EDX.ipynb' is a jupyter notebook file. This file describes the data processing in order to observe the temporal correlation between the electrons and X-rays. |
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no |
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Call Number |
UA @ admin @ c:irua:169112 |
Serial |
6888 |
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Author |
Derks, K. |
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Title |
Scanning Michael Sweerts and Michaelina Wautier : uncovering the working methods of 17th-century Brussels artists by means of MA-XRF examination |
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Doctoral thesis |
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2023 |
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634 p. |
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Doctoral thesis; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS) |
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This dissertation focuses on the materials and techniques used by the Brussels artists Michael Sweerts (1618-1664) and Michaelina Wautier (1614-1689). It tries to answer the following research questions: 1.Did 17th-century Brussels-based artists use idiosyncratic painting materials and techniques, and can their work be distinguished from paintings created in other artistic centers based on these materials and techniques? 2.How did Sweerts and Wautier influence each other’s work? In order to answer the research questions, a selection of relevant and representative paintings from Sweerts’ and Wautier’s oeuvre has been studied with MA-XRF scanning and microscopic examination. The results are discussed in volume 2 of this dissertation, and form the basis upon which the chapters in volume 1 are built. MA-XRF scanning is a non-destructive imaging technique based on the technique of X-ray fluorescence (XRF). The technique allows for the collection of elemental information about the materials present in a work of art. The work presented in this dissertation has shed more light on the working methods of Sweerts and Wautier. It has shown they both showed an openness and willingness to continue learning and developing as an artist. Wautier did not feel constrained to work only in one genre and apparently carried on developing her skills throughout her career, as evidenced by Flower Garland with Butterfly. She might have trained with a specialized artist to master their idiosyncratic working methods and this diverse genre. This suggests that Wautier had an interest in art education. Sweerts too had a passion for art education: he was involved in the drawing academy of Camillo Pamphilj in Rome, and later established his own academy for life drawing in Brussels. Sweerts’ work clearly shows the influence of his Italian contemporaries. Whilst living in Rome, he adapted his working methods to local customs such as working on brightly colored grounds. Wautier’s oeuvre shows that she was open to explore different genres and that she took inspiration from her contemporaries, including Theodoor van Loon and Daniël Seghers. In doing so, she furthered the development of different genres as she added original elements to her compositions. It is the conclusion of this dissertation that Michaelina Wautier can thus be considered one of the innovative artists of mid-17th-century Flemish painting, who inspired other artists in the Low Countries, including Michael Sweerts. |
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Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:197182 |
Serial |
8927 |
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Srivastava, A.; Van Passel, S.; Laes, E. |
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Title |
Assessing the success of electricity demand response programs : a meta-analysis |
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A1 Journal article |
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2018 |
Publication |
Energy Research and Social Science |
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40 |
Issue |
40 |
Pages |
110-117 |
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A1 Journal article; Economics; Engineering Management (ENM) |
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This paper conducts a meta-analysis of 32 electricity demand response programs in the residential sector to understand whether their success is dependent on specific characteristics. The paper analyses several regression models using various combinations of variables that capture the designs of the programs and the socio-economic conditions in which the programs are implemented. The analysis reveals that demand response programs are more likely to succeed in highly urbanized areas, in areas where economic growth rates are high, and in areas where the renewable energy policy is favorable. These findings provide useful guidance in determining where and how to implement future demand response programs. |
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000430737800014 |
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2017-12-28 |
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ISSN |
2214-6296 |
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Additional Links |
UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles |
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Times cited |
18 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:149027 |
Serial |
6154 |
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Author |
Górka, M.; Jedrysek, M.O.; Maj, J.; Worobiec, A.; Buczyńska, A.; Stefaniak, E.; Krata, A.; Van Grieken, R.; Zwozdziak, A.; Sówka, I.; Zwozdziak, J.; Lewicka-Szczebak, D. |
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Title |
Comparative assessment of air quality in two health resorts using carbon isotopes and palynological analyses |
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A1 Journal article |
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2009 |
Publication |
Atmospheric environment |
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43 |
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3 |
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682-688 |
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A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP) |
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This paper describes results of applying the palynological and carbon isotopic analysis of the organic fraction of Total Suspended Particles (TSP) to discriminate distinct pollution sources and assess the anthropogenic impact for the investigated areas. The samples of atmospheric particles were collected in Czerniawa and Cieplice (two health resorts in Lower Silesia, SW Poland) twice a year in summer and winter season (from July 2006 to February 2008). The palynological spectra represent in the vast majority local plant communities without a noticeable contribution of long-transported plant particles. Palynological analysis revealed also differences in the specificity of the two sampling areas, i.e. the higher contribution of identified organic material in Czerniawa stands for more natural character of this site, but is also responsible for the higher allergic pressure when compared to Cieplice. The carbon isotopic composition of TSP varied seasonally (ä13C value from −27.09 in summer to −25.47 in winter). The increased ä13C value in winter (heating period) is most probably caused by uncontrolled contribution of coal soot. On the basis of isotopic mass balance the calculated contribution of anthropogenic organic particles in the atmosphere reached in winter season 72% in Czerniawa and 79% in Cieplice. |
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000262737900024 |
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2008-10-15 |
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1352-2310 |
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UA library record; WoS full record; WoS citing articles |
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no |
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UA @ admin @ c:irua:72492 |
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7686 |
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Roegiers, J.; van Walsem, J.; Denys, S. |
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CFD- and radiation field modeling of a gas phase photocatalytic multi-tube reactor |
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A1 Journal article |
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2018 |
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Chemical engineering journal |
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338 |
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287-299 |
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A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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This paper focusses on the development of a Multiphysics model as a tool for assessing the performance of a multi-tube photoreactor. The model predicts the transient behavior of acetaldehyde concentration, as a model compound for the organic fraction of the indoor air pollutants, under varying sets of conditions. A 3D-model couples radiation field modeling with reaction kinetics and fluid dynamics in order to simulate the transport of the pollutant as it progresses through the reactor. A model-based approach is proposed to determine the layer thickness and refractive index of different P25-powder modified solgel coatings, using an optimization procedure to estimate these parameters based on UV-irradiance measurements. The radiation field model was able to accurately predict the irradiance on the catalytic surface within the reactor. Consequently, the radiation field model was used to define an irradiance dependent reaction rate constant in a coupled Multiphysics model. An optimization routine was deployed to estimate the adsorption, desorption- and photocatalytic reaction rate constants on the TiO2-surface, using experimentally determined, transient outlet concentrations of acetaldehyde. Additionally, a validation test was performed in an air-tight climate chamber at much higher flow rates, higher irradiance and realistic indoor pollutant concentrations to emphasize the reliability and accuracy of the parameters for adsorption, desorption and photocatalytic reaction. The developed model makes it possible to optimize the reactor design and scale-up for commercial applications. |
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000427618400031 |
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2018-01-08 |
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ISSN |
1385-8947; 1873-3212 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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no |
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Call Number |
UA @ admin @ c:irua:149115 |
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7589 |
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Bottari, F.; Moretto, L.M.; Ugo, P. |
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Impedimetric sensing of the immuno-enzymatic reaction of gliadin with a collagen-modified electrode |
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A1 Journal article |
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2018 |
Publication |
Electrochemistry communications |
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97 |
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51-55 |
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A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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This paper presents a previously unexplored biosensing strategy for detecting gliadin which exploits the crosslinking of gliadin with collagen, catalyzed by transglutaminase at the interfacial electron transfer rate, on a modified electrode. The process is monitored by electrochemical impedance spectroscopy using a glassy carbon electrode coated with a collagen layer. To validate the specificity of the response as well as to eliminate possible interferences from other proteins, such as soy protein or casein, the captured gliadin is further reacted with a specific anti-gliadin antibody. Changes in charge transfer resistance, measured from the Nyquist plots, scale linearly with the gliadin concentration in the range 5-20 mg/L, a range suitable for testing the gliadin concentration in gluten-free food commodities. |
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000451326800011 |
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2018-10-10 |
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1388-2481; 1873-1902 |
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UA library record; WoS full record; WoS citing articles |
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no |
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Call Number |
UA @ admin @ c:irua:156285 |
Serial |
8067 |
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van Loon, A.; Noble, P.; Krekeler, A.; van der Snickt, G.; Janssens, K.; Abe, Y.; Nakai, I.; Dik, J. |
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Title |
Artificial orpiment, a new pigment in Rembrandt's palette |
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A1 Journal article |
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2017 |
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Heritage science |
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5 |
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26 |
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A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
This paper reports on how the application of macro X-ray fluorescence (MA-XRF) imaging, in combination with the re-examination of existing paint cross-sections, has led to the discovery of a new pigment in Rembrandt's palette: artificial orpiment. In the NWO Science4Arts 'ReVisRembrandt' project, novel chemical imaging techniques are being developed and applied to the study of Rembrandt's late paintings in order to help resolve outstanding questions and to gain a better understanding of his late enigmatic painting technique. One of the selected case studies is the Portrait of a Couple as Isaac and Rebecca, known as 'The Jewish Bride', dated c. 1665 and on view in the Rijksmuseum. During the re-installation of the Rijksmuseum in 2013, the picture was scanned using the Bruker M6 Jetstream MAXRF scanner. The resulting elemental distribution maps made it possible to distinguish many features in the painting, such as bone black remains of the original hat (P, Ca maps), and the now discolored smalt-rich background (Co, Ni, As, K maps). The arsenic (As) map also revealed areas of high-intensity in Isaac's sleeve and Rebecca's dress where it could be established that it was not related with the pigment smalt that also contains arsenic. This pointed to the presence of a yellow or orange arsenic-containing pigment, such as realgar or orpiment that is not associated with the artist's palette. Subsequent examination of existing paint cross-sections from these locations taken by Karin Groen in the 1990s identified isolated, almost perfectly round particles of arsenic sulfide. The round shape corresponds with published findings on a purified form of artificial orpiment glass obtained by dry processing, a sublimation reaction. In bright field, the particles characteristically exhibit a dark cross in the middle caused by internal light reflections. The results of additional non-invasive techniques (portable XRD and portable Raman) are discussed, as well as the implications of this finding and how it fits with Rembrandt's late experimental painting technique. |
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000404916400001 |
Publication Date |
2017-06-02 |
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Abbreviated Series Title |
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ISSN |
2050-7445 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Times cited |
6 |
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Notes |
; This research is part of the Science4Arts Program, funded by the Netherlands Organization for Scientific Research (NWO) (Grant No. SFA-11-12). GVdS is supported by the Baillet Latour Fund. The authors would like to thank Lisette Vos, Rijksmuseum Amsterdam, for assisting with the MA-XRF scanning; Arisa Izumi and Airi Hirayama, students of the Tokyo University of Science, and Frederik Vanmeert, University of Antwerp, for assisting with the pXRD and pRaman measurements. We are also grateful to Rob Erdmann, Rijksmuseum Amsterdam, who made the curtain viewer to facilitate comparison of the visible image with the elemental distribution maps of the painting. ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:144864 |
Serial |
5479 |
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Van Loon, J.; De Jong, M.; De Wael, K.; Du Bois, E. |
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Title |
Transposing testing from lab to on-site environment : a case of cocaine powder sampling |
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P3 Proceeding |
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2020 |
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P3 Proceeding; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Product development |
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Abstract |
This paper reports on the transition process to convert a specific lab technique to the on-site, real-life environment. Bringing a lab test to an on-site environment involves many difficulties regarding to the context, people skills and environmental support. Within this project, a case about sampling for an electrochemical measurement, was investigated as a basis to reason upon some general conclusions related to the process of transposing lab-tests to an on-site environment. The current lab test was analysed and compared with a focus group discussion with future users. Based on the findings, assumptions for the new sampling technique in the specific case were formulated. New low-tech methods to achieve the sampling were extensively tested and verified. Starting from this chosen case an argumentation was set up to generalise the conclusions, by reasoning on other cases of products that already passed this transition to the field. Based on a comparison, we could discuss that the selected parameters related to impact of the context environment, of the people that should handle the tests, related to the reasons for transposing the technology, and related to the technology that will be transposed to the on-site environment, were of importance of almost all cases and can therefore be considered as context-independent and related to the transfer to on-site testing. |
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978-94-6384-131-3 |
Additional Links |
UA library record |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:169896 |
Serial |
6637 |
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Author |
Magalhães Cunha, S. |
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Title |
Wave-packet dynamics and electronic transport properties in 2D materials |
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Doctoral thesis |
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2022 |
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219 p. |
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Doctoral thesis; Condensed Matter Theory (CMT) |
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Abstract |
This piece of work is twofold. First, the time evolution of wave-packets in 2D systems is analyzed by the Split-Operator technique in three different scenarios: in multilayer phosphorene, the transient oscillations in the time-dependent average of position and momentum were observed due to the zitterbewegung effect, and the wave packet propagates non-uniformly along the space deforming itself into an elliptical shape. These results were corroborated by the Green’s function formalism except for large values of the wave-vector and long times; in 2D semiconductor quantum wires (QWs) with anisotropic effective masses and different angle orientations with respect to the anisotropic axis. We have shown that the greater this angle, the smaller is the energy levels spacing implying in an increase of the accessible electronic states. Additionally, for non-null magnetic field, the quantum Hall edge states are significantly affected by the edge orientation. In the anisotropic case damped oscillations in the average values of velocity in both x and y directions where obtained. Theses oscillations are originated by the QW geometry but also from subwavepackets with different momentum orientations, whereas for isotropic QWs the wavepacket disperses without splitting; in the third scenario the split-operator technique was used to study the Landau levels, the wave packet trajectories and velocities of electrons in graphene at low-energy regime described by a modified Dirac equation where the momentum-operator is written in a generalized form as result of applying the position-dependent translation operator formalism (PDTO). In the second part of this thesis, the electronic and tunneling properties of α − T3 lattices were studied. Electrons in these lattices behave analogous to integer-spin Dirac Fermions. The presence of a third atomic site in the unit cell leads to a flat band in the energy spectrum, providing unique electronic and tunneling properties. The presence of a super-periodic potential and the inclusion of symmetry-breaking terms results in deviations of the atomic equivalence between the atomic sites affecting the Dirac points and the band-gap. Small deviations in the equivalence between the atomic sites and the number of barriers change the transmission properties in these lattices. Additionally, new tunneling regions are possible by adjusting the symmetry between the atomic sites and affect the omnidirectional total transmission called super-Klein tunneling observed in these lattices. We compare those results to the tunneling probabilities through regions where the energy spectrum changes from linear with a middle flat band to a hyperbolic dispersion. |
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UA library record |
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UA @ admin @ c:irua:189191 |
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7227 |
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