| Records |
| Author |
Vekemans, B.; Janssens, K.; Vincze, L.; Adams, F.; van Espen, P. |
| Title |
Analysis of X-ray spectra by iterative least squares (AXIL): new developments |
Type |
A1 Journal article |
| Year |
1994 |
Publication |
X-ray spectrometry |
Abbreviated Journal |
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| Volume |
23 |
Issue |
|
Pages |
278-285 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
A1994QF68500008 |
Publication Date |
2005-05-28 |
| 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 |
0049-8246 |
ISBN |
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Additional Links  |
UA library record; WoS full record; WoS citing articles |
| 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 |
| Call Number |
UA @ admin @ c:irua:8933 |
Serial |
5471 |
| Permanent link to this record |
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| Author |
Schalm, O.; Cabal, A.; van Espen, P.; Laquière, N.; Storme, P. |
| Title |
Improved radiographic methods for the investigation of paintings using laboratory and synchrotron X-ray sources |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
|
| Volume |
26 |
Issue |
5 |
Pages |
1068-1077 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
It is generally known that radiographic inspection of 1517th century paintings can easily be done with a polychromatic X-ray source using a voltage between 20 kV and 40 kV in combination with classic X-ray films. Unfortunately, the spatial structure of numerous 19th and early 20th century paintings cannot be visualized with conventional radiography due to several reasons such as the use of lead white grounds or low absorbing pigments. Radiographic images are blurred or worse, they do not contain the picture of the painting. During the last decades, many technological innovations have been introduced in the field of radiography but their possibilities in cultural heritage have not been explored in full detail. In our investigation we used phosphor imaging plates, energy dispersive detectors and CCD-cameras in combination with synchrotron radiation and conventional X-ray tubes in order to improve the quality of radiographic images. Several promising techniques that could improve the quality of radiographs of paintings were identified. |
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Thesis |
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Place of Publication |
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Editor |
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Wos |
000289731900023 |
Publication Date |
2011-04-11 |
| 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 |
0267-9477 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| 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 |
| Call Number |
UA @ admin @ c:irua:89928 |
Serial |
8070 |
| Permanent link to this record |
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| |
| Author |
Serneels, S.; Faber, K.; Verdonck, T.; van Espen, P.J. |
| Title |
Case specific prediction intervals for tri-PLS1 : the full local linearisation |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Chemometrics and intelligent laboratory systems |
Abbreviated Journal |
|
| Volume |
108 |
Issue |
2 |
Pages |
93-99 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A new method to estimate case specific prediction uncertainty for univariate trilinear partial least squares (tri-PLS1) regression is introduced. This method is, from a theoretical point of view, the most exact finite sample approximation to true prediction uncertainty that has been reported up till now. Using the new method, different error sources can be propagated, which is an advantage that cannot be offered by data driven approaches such as the bootstrap. In a concise example, it is illustrated how the method can be applied. In the Appendix, efficient algorithms are presented to compute the estimates required. |
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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 |
000295310000002 |
Publication Date |
2011-05-12 |
| 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 |
0169-7439; 1873-3239 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| 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 |
| Call Number |
UA @ admin @ c:irua:92788 |
Serial |
7580 |
| Permanent link to this record |
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| Author |
Alejo, ellys; Morales, M.C.; Nuñez, V.; Bencs, L.; Van Grieken, R.; van Espen, P. |
| Title |
Monitoring of tropospheric ozone in the ambient air with passive samplers |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Microchemical journal |
Abbreviated Journal |
|
| Volume |
99 |
Issue |
2 |
Pages |
383-387 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Two sampling campaigns in suburban places in the north zone of Santa Clara city, Cuba, have been carried out on a weekly base with the use of Radiello passive diffusion tubes in order to monitor the tropospheric ozone (O3) levels in 2010. The first campaign was scheduled from February to April (cold season) and the second one in August and October (warm season), both of them at two sampling sites, i.e., Farm and School of Art Instructors. After aqueous extraction, the samples were analyzed by UVVIS spectrophotometry. A seasonal trend was observed with the maximum O3 concentrations in the cold season and the minimum levels in the warm season. Samples collected during the cold season showed the highest O3 levels. Higher levels were reached at the Farm site with average values of about 58 ± 12 μg/m3, which exceeded the limit of the Cuban Standard 99:1999. In the warm season, the O3 concentrations were similar for both sites, but lower than those observed in the cold season. The overall, seasonal average value was found to be 24 μg/m3. Despite the higher weekly average temperatures in August, the O3 concentrations during this month showed the lowest values of the whole sampling period, which finding is in agreement with that reported by the Meteorological Institute of Cuba. Mathematical models, based on the Cochrane-Orcutt algorithm, were fitted to the acquired data set to explain the change in the tropospheric ozone concentrations under various meteorological conditions during the two campaigns. The correlation coefficients for both the cold and the warm seasons demonstrated a strong correlation, i.e., 0.779 and 0.951, respectively. The high correlation of wind speed in the model from the first sampling campaign explains the sharp decrease in O3 concentrations at the SAI sampling site from the sixth week of sampling. |
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Thesis |
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Place of Publication |
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Editor |
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Wos |
000295770700034 |
Publication Date |
2011-06-26 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| 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 |
| Call Number |
UA @ admin @ c:irua:93294 |
Serial |
8277 |
| Permanent link to this record |
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| Author |
Buydens, L.; van Espen, P.; Rutan, S. |
| Title |
CAC-2010 : Twelfth international conference on chemometrics in analytical chemistry |
Type |
Editorial |
| Year |
2011 |
Publication |
Analytica chimica acta |
Abbreviated Journal |
|
| Volume |
705 |
Issue |
1/2 |
Pages |
1 |
| Keywords |
Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
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| Address |
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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 |
000295993900001 |
Publication Date |
2011-08-14 |
| 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 |
| 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 |
| Call Number |
UA @ admin @ c:irua:93573 |
Serial |
7570 |
| Permanent link to this record |
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| |
| Author |
Kindratenko, V.V.; van Espen, P.J.M.; Treiger, B.A.; Van Grieken, R.E. |
| Title |
Fractal dimensional classification of aerosol particles by computer-controlled scanning electron microscopy |
Type |
A1 Journal article |
| Year |
1994 |
Publication |
Environmental science and technology |
Abbreviated Journal |
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| Volume |
28 |
Issue |
|
Pages |
2197-2202 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
A1994PP82900033 |
Publication Date |
2007-05-30 |
| 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 |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:9497 |
Serial |
7983 |
| Permanent link to this record |
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| Author |
Treiger, B.; Injuk, J.; Bondarenko, I.; van Espen, P.; Van Grieken, R.; Breitenbach, L.; Wätjen, U. |
| Title |
Non-linear mapping of microbeam proton-induced X-ray emission data for source identification of North Sea aerosols |
Type |
A1 Journal article |
| Year |
1994 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
|
| Volume |
49 |
Issue |
4 |
Pages |
345-353 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
A1994NM41200004 |
Publication Date |
2003-04-25 |
| 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 |
0584-8547; 1873-3565 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| 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 |
| Call Number |
UA @ admin @ c:irua:9500 |
Serial |
8314 |
| Permanent link to this record |
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| |
| Author |
Janssens, K.; Vekemans, B.; Adams, F.; van Espen, P.; Mutsaers, P. |
| Title |
Accurate evaluation of \mu-PIXE and \mu-XRF spectral data through iterative least squares fitting |
Type |
A1 Journal article |
| Year |
1996 |
Publication |
Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms
T2 – 7th International Conference on Particle Induced X-ray Emission and Its Analytical Applications, MAY 26-30, 1995, Abano Terme, Italy |
Abbreviated Journal |
7th International Conference on Particle Induced X-ray Emission and Its Analytical Applications, MAY |
| Volume |
109 |
Issue |
|
Pages |
179-185 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3) |
| Abstract |
The integration of the nonlinear least squares X-ray spectrum evaluation progam AXIL. into a mu-PIXE and a mu-XRF setup is discussed. The use of the software when procesing data sets derived from biological and geological samples is described. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
A1996UV44400035 |
Publication Date |
2002-07-25 |
| 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 |
0168-583x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:95887 |
Serial |
5457 |
| Permanent link to this record |
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| Author |
Cabal Rodríguez, A.E.; Leyva Pernia, D.; Schalm, O.; van Espen, P.J.M. |
| Title |
Possibilities of energy-resolved X-ray radiography for the investigation of paintings |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Analytical and bioanalytical chemistry |
Abbreviated Journal |
|
| Volume |
402 |
Issue |
4 |
Pages |
1471-1480 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
X-ray radiographic images of paintings often show little or no contrast. In order to increase the contrast in radiographic images we measured the X-ray spectrum of a low power X-ray tube, after passing through the painting, with a high energy-resolution SDD detector. To obtain images, the detector is collimated with a 400 mu m diameter pinhole and the painting was moved through the beam in the x and y-direction using a dwell time of a few seconds per pixel. The data obtained consists of a data cube of, typically, 200 x 200 pixels and a 512-channel X-ray spectrum for each pixel, spanning the energy range from 0 to 40 keV. Having the absorbance spectrum available for each pixel, we are able, a posteriori, to produce images by edge subtraction for any given element. In this way high contrast, element-specific, images can be obtained. Because of the high energy-resolution a much simpler edge subtraction algorithm can be applied. We also used principal-component imaging to obtain, in a more automated way, images with high contrast. Some of these images can easily be attributed to specific elements. It turns out that preprocessing of the spectral data is crucial for the success of the multivariate image processing. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000299842000008 |
Publication Date |
2011-07-14 |
| 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 |
1618-2642; 1618-2650 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| 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 |
| Call Number |
UA @ admin @ c:irua:96200 |
Serial |
8394 |
| Permanent link to this record |
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| Author |
Piñera, I.; Cruz, C.M.; van Espen, P.; Abreu, Y.; Leyva, A. |
| Title |
Study of dpa distributions in electron irradiated YBCO slabs through MCCM algorithm |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms |
Abbreviated Journal |
|
| Volume |
274 |
Issue |
|
Pages |
191-194 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The Monte Carlo assisted Classical Method (MCCM) consists on a calculation procedure for determining the displacements per atom (dpa) distribution in solid materials. This algorithm allows studying the gamma and electron irradiation damage in different materials. It is based on the electrons elastic scattering classic theories and the use of Monte Carlo simulation for the physical processes involved. The present study deals with the Monte Carlo simulation of electron irradiation effects on YBa2Cu3O7-x (YBCO) slabs using the MCNPX code system. Displacements per atom distributions are obtained through the MCCM for electron irradiation up to 10 MeV. In-depth dpa profiles for electrons and positrons are obtained and analysed. Also, dpa contributions from each atomic specie in the material are calculated. It was found that the dpa distribution is more homogeneous in the material volume when increasing energy of incident electrons. Also, the dpa produced by positrons has no relevance when irradiating with electrons, in contrast with previous similar gamma irradiation studies. All the results are presented and discussed in this contribution. (C) 2011 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000301611900031 |
Publication Date |
2011-12-05 |
| 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 |
0168-583x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:97819 |
Serial |
8595 |
| Permanent link to this record |
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| |
| Author |
Abreu, Y.; Cruz, C.M.; van Espen, P.; Pérez, C.; Piñera, I.; Leyva, A.; Cabal, A.E. |
| Title |
Electric field gradient calculations in ZnO samples implanted with 111In(111Cd) |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Solid state communications |
Abbreviated Journal |
|
| Volume |
152 |
Issue |
5 |
Pages |
399-402 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A first-principles study of the electric field gradient (EFG) calculated for ideal and In-111(Cd-111) implanted ZnO samples is reported in the present work. The study was made for ZnO ideal hexagonal structures and supercells were introduced in order to consider the possible implantation environments. The calculation was done using the “WIEN2k” code within the density functional theory, the exchange and correlation effects were determined by the GGA approximation. Three possible In-111(Cd-111) implantation configurations were studied, one substitutional incorporation at cation site and two interstitials. The obtained EFG values for the ideal structure and the substitutional site are in good agreement with the experimental reports measured by perturbed angular correlation (PAC) and high precision nuclear magnetic resonance (NMR). Thus, the ascription of substitutional incorporation of In-111(Cd-111) probe atom at the ZnO cation site after annealing was confirmed. (C) 2011 Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000301329200016 |
Publication Date |
2011-12-09 |
| 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 |
|
Edition |
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| ISSN |
0038-1098 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:97821 |
Serial |
7857 |
| Permanent link to this record |
