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Author Hellemans, K.; Cagno, S.; Bogana, L.; Janssens, K.; Mendera, M. pdf  doi
openurl 
  Title LA-ICP-MS labels early medieval Tuscan finds from Siena and Donoratico as late natron glass Type A1 Journal article
  Year (down) 2019 Publication Journal of Archaeological Science: Reports Abbreviated Journal  
  Volume 23 Issue 23 Pages 844-853  
  Keywords A1 Journal article; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The late antique/early medieval age in Central Italy is a well-suited context to verify the implications of the end of the natron glass supplies, and to explore the beginnings of the new plant-ash glass technology. We present the results of a LA-ICP-MS analysis campaign conducted on archaeological glass finds excavated at the Santa Maria della Scala hospital site in Siena and in Donoratico. This provided us with major, minor and trace element quantitative data for 49 glass samples belonging to drinking vessels and lamps, dated mainly between the 5th and the 8th century. On the basis of these data, we have sought to identify the working processes and possible glassware trade that are reflected in the glass composition. Major and minor element contents revealed that most samples, also at the later boundary of the explored timeframe, fit well within known late Roman glass classifications (e.g. HIMT, Levantine). Trace element analysis provided further information on the raw materials that were used in the glassmaking process, indicating the use of coastal sands as a silica source and allowing us to formulate different hypotheses on the materials used for the colouring process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000462119900071 Publication Date 2018-12-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2352-409x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 3 Open Access  
  Notes ; This research was supported by the Hercules Foundation (Brussels, Belgium) under grant AUHA09004, FWO (Brussels, Belgium) project nos. G.0C12.13 and G.01769.09. We would also like to thank our referees for their valuable input during the review process. ; Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:159450 Serial 5685  
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Author Hellemans, K. url  openurl
  Title Laser ablation ICP-MS as a tool for surface analysis in comparison to other elemental analysis methods Type Doctoral thesis
  Year (down) 2019 Publication Abbreviated Journal  
  Volume Issue Pages 229 p.  
  Keywords Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Dit onderzoek presenteert een overzicht van de mogelijkheden van LA-ICP-MS als een techniek voor kwantitatieve analyse, bepalen van isotoopverhoudingen en elementaire beeldvorming. Hiervoor wordt de techniek zelf voorgesteld en worden de belangrijkste parameters die een invloed hebben op de kwaliteit van een LA-ICP-MS meting beschreven. Voor kwantitieve analyse worden de huidige calibratiestrategieën voor LA-ICP-MS toegelicht, zowel op het vlak van selectie en bereiding van standaarden als op het vlak van dataverwerking. Daarnaast werd een nieuwe calibratiestrategie voorgesteld, gebaseerd op een lineaire combinatie van standaarden. Een case study met de traditionele calibratiestrategie uit de literatuur werd uitgevoerd en vergeleken met data van SEM-EDX om een referentiekader te schetsen voor de performantie van de techniek. In een tweede case study werd onze nieuwe calibratiestrategie toegepast en werd er uitsluitend gebruik gemaakt van LA-ICP-MS, wat uitstekende resultaten opleverde. Met het oog op het bepalen van isotoopverhoudingen, werd er onderzocht wat de limieten zijn van het gebruik van een lage resolutie quadrupool massaspectrometer voor deze bepaling. Dit stelde ons in staat om de te verwachten accuraatheid en precisie in te schatten. De performantie bleek goed genoeg te zijn om weapon-grade plutonium te onderscheiden van global fall-out, zoals het werd aangetoond in de case study omtrent dit onderwerp. Uiteindelijk hebben we ook LA-ICP-MS geëvalueerd als een techniek voor elementaire beeldvorming, waarbij we tevens de meest courante multivariate data analyse hebben beschreven. Om de techniek te plaatsen tegenover andere elementaire technieken, werd een historisch verffragment geanalyseerd dat in het verleden reeds geanalyseerd was met SEM-EDX and μ-XRD. Op die manier konden we de resultaten accuraat vergelijken met de andere technieken.  
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  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:160063 Serial 8152  
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Author Hellemans, K.; Vincke, A.; Cagno, S.; Herremans, D.; De Clercq, W.; Janssens, K. pdf  doi
openurl 
  Title Composition and state of alteration of 18th-century glass finds found at the Cistercian nunnery of Clairefontaine, Belgium Type A1 Journal article
  Year (down) 2014 Publication Journal of archaeological science Abbreviated Journal J Archaeol Sci  
  Volume 47 Issue Pages 121-133  
  Keywords A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract A hundred 18th-century glass fragments were recovered at the Clairefontaine monastery in the Belgian province of Luxembourg. They were analysed by a combination of SEM-EDX and LA-ICP-MS in order to determine their major composition as well as their trace element signature. Multivariate statistical methods such as hierarchical clustering and principal component analysis were used to divide the glass fragments into four main groups: potassium-rich glass, sodium-rich glass, potassium/lime-rich glass and high-lime-low-alkali glass. Within every group, not only a similarity in composition is observed, but also in colour, morphology and deterioration patterns. Potash glass fragments are the most abundant and show extensive deterioration; two classes of potash glass were identified: one similar to certain Central European glass compositions, while the other one, characterised by large variations in potash: lime ratio, may be attributed to local (regional) glass production. (C) 2014 Elsevier Ltd. All rights reserved.  
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  Language Wos 000339037300012 Publication Date 2014-04-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0305-4403 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.602 Times cited 12 Open Access  
  Notes ; Archaeological fieldwork at Clairefontaine was directed by Prof. Dr. J. De Meulemeester (dagger) and financed by the Walloon Government. Post-excavation research is carried out within the framework of the PhD-project (FNR Luxembourg BFR06-80): “The material culture of Clairefontaine abbey”. This investigation was supported by the Interuniversity Attraction Poles Programme (Belgian Science Policy – IUAP VI/16) and by the HERCULES foundation. This work was partly supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/F50. ; Approved Most recent IF: 2.602; 2014 IF: 2.196  
  Call Number UA @ admin @ c:irua:118711 Serial 5536  
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Author Cagno, S.; Hellemans, K.; Lind, O.C.; Skipperud, L.; Janssens, K.; Salbu, B. doi  openurl
  Title LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia Type A1 Journal article
  Year (down) 2014 Publication Environmental science : processes & impacts Abbreviated Journal Environ Sci-Proc Imp  
  Volume 16 Issue 2 Pages 306-312  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Information on Pu in environmental samples is traditionally based on the determination of the 240+239PU activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total 239+240PU activity, determination of the Pu-240/Pu-239 ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of Pu-239/Pu-240 ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the Pu-240/Pu-239 ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples.  
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  Language Wos 000331504100015 Publication Date 2013-12-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7887; 2050-7895 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.592 Times cited 10 Open Access  
  Notes ; This work was supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/F50, and the Hercules fund, Brussels (grant A11/0387). ; Approved Most recent IF: 2.592; 2014 IF: 2.171  
  Call Number UA @ admin @ c:irua:115791 Serial 5684  
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Author Nuyts, G.; Cagno, S.; Hellemans, K.; Veronesi, G.; Cotte, M.; Janssens, K. url  doi
openurl 
  Title Study of the early stages of Mn intrusion in corroded glass by means of combined SR FTIR/\muXRF imaging and XANES spectroscopy Type P1 Proceeding
  Year (down) 2013 Publication Procedia Chemistry T2 – Youth in Conservation of Cultural Heritage Conference (YOCOCU), June 18-20, 2012, University of Antwerp, Antwerp, Belgium Abbreviated Journal  
  Volume Issue Pages 239-247  
  Keywords P1 Proceeding; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Historical glass, especially medieval glass, can undergo weathering under the influence of time and environmental conditions. The aim of this investigation was to better understand the processes involved in this natural degradation process by studying artificially altered glass samples prepared for the use of evaluation of conservation methods. Non-durable glass sensors produced by the Fraunhofer Institute (type M1.0) were used as a starting material for artificial alteration. These were immersed in acidic (pH = 0, 2, 4) and neutral solutions (1 h – 8 h). In a second stage the glass samples were immersed in a 0.5 M MnCl2 solution (24 h, 48 h and 72 h), allowing intrusion of Mn from the solution into the gel layer. The samples were characterized at different stages with reflectance FTIR spectroscopy, mu XRF mapping and mu XANES. All measurements were carried out at ESRF, beamline ID21. Reflectance FTIR spectroscopy measurements were performed in the 800 4000 cm(-1) range. Cluster analysis of the resulting maps evidenced the rapid growth of the gel layer in strong acidic conditions. The average spectra for each cluster feature show for the original glass a strong Si-O- stretching band between 900 and 1000 cm(-1), whereas the gel layer could be identified by the increasing Si-O-Si bands around 1100 and 1250 cm(-1). mu XRF maps were recorded at different stages of the experiment at energies around the Mn-K edge (6.539 keV) and with a step size of 2 by 2 m. These confirm the leaching of K+ and Ca+2 from the glass and the intrusion of Mn from the solution. Mn was found throughout the entire gel layer, but with a concentration gradient peaking at the surface. XANES point measurements were recorded at various points where Mn was present. No spatial variation was found, but linear combination fitting of the spectra with various Mn reference compounds indicated that Mn2+Mn23+O4 is the main Mn compound in the gel layer, as was hypothesised by Watkinson et al. The standard corroded glass samples studied here can be used for the evaluation of conservation treatments in follow-up experiments. (C) 2013 The Authors. Published by Elsevier B.V. Selection and peer-review under responsibility of the IA-CS (Italian Association of Conservation Scientists) and University of Antwerp  
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  Language Wos 000321673900030 Publication Date 2013-04-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 8 Series Issue Edition  
  ISSN 1876-6196 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 4 Open Access  
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA XANES “meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. We gratefully acknowledge ESRF for granting beamtime (experiment EC873). ; Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:109871 Serial 5851  
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Author Mudronja, D.; Vanmeert, F.; Hellemans, K.; Fazinic, S.; Janssens, K.; Tibljas, D.; Rogosic, M.; Jakovljevic, S. pdf  doi
openurl 
  Title Efficiency of applying ammonium oxalate for protection of monumental limestone by poultice, immersion and brushing methods Type A1 Journal article
  Year (down) 2013 Publication Applied physics A : materials science & processing Abbreviated Journal Appl Phys A-Mater  
  Volume 111 Issue 1 Pages 109-119  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Samples of cretaceous limestone have been treated with three application methods (poultice, immersion and brushing) using different concentrations of ammonium oxalate solution (AmOx) and varying treatment time in order to test the efficiency of surface and in-depth formation of a protective layer of calcium oxalate (CaOx). Synchrotron-based microanalytical techniques (SR-mu XRD with 12.5 mu mx7.5 mu m (HxV) probe size, SR-mu FTIR with 10 mu mx10 mu m and 8 mu mx20 mu m probe sizes) and laboratory mu FTIR, XRD and SEM have been employed for analysis of the treated samples. Synchrotron-based techniques showed variations in the CaOx distribution along the surface on a micrometer scale. All treatments resulted in the development of a CaOx layer with a maximum thickness of approximately 40 mu m. Application by the brushing method with 10 1-min applications with 5-min breaks during one hour showed a development of the calcium oxalate layer equivalent to the poultice treatment taking 10 h. This treatment could be preferred for large marble or limestone surfaces where poultice usage is economically not feasible.  
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  Language Wos 000316075700014 Publication Date 2012-10-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0947-8396 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.455 Times cited 13 Open Access  
  Notes ; This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA 'XANES meets ELNES' (Research Fund, University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0704.08 and G.01769.09. The research leading to these results has received financial support by the Access to Research Infrastructures activity in the 7th Framework Programme of the EU (CHARISMA Grant Agreement No. 228330). ; Approved Most recent IF: 1.455; 2013 IF: 1.694  
  Call Number UA @ admin @ c:irua:108262 Serial 5584  
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Author Rouchon, V.; Duranton, M.; Burgaud, C.; Pellizzi, E.; Lavédrine, B.; Janssens, K.; de Nolf, W.; Nuyts, G.; Vanmeert, F.; Hellemans, K. doi  openurl
  Title Room-temperature study of iron gall ink impregnated paper degradation under various oxygen and humidity conditions : time-dependent monitoring by viscosity and X-ray absorption near-edge spectrometry measurements Type A1 Journal article
  Year (down) 2011 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 83 Issue 7 Pages 2589-2597  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Many western manuscripts were written using iron gall inks. These inks can damage the paper via two major mechanisms: (a) acid hydrolysis, enhanced by humidity, and (b) oxidative depolymerization provoked by the presence of oxygen and free iron(II) ions. The degradation of unsized Whatman paper impregnated with different combinations of iron sulfate, gallic acid, and gum arabic was studied at room temperature in order to assess the relative importance of each mechanism. The samples were stored in various environments including a dry and/or an oxygen-free atmosphere. The cellulose depolymerization was monitored by viscometry and related to changes in the oxidation state of iron, determined by X-ray absorption near-edge spectrometry. The results indicate that residual amounts of oxygen (less than 0.1%) promote cellulose depolymerization, whereas the level of relative humidity has no impact. The cellulose depolymerization also appears closely correlated to oxidative mechanisms. Regarding the oxidation of iron, it only occurs in the simultaneous presence of oxygen and moisture, suggesting the occurrence of rustlike oxidative mechanisms. Finally, the presence of gallic acid has a strong influence, which is only partially explained by its capacity to reduce iron(III) to iron(II).  
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  Language Wos 000288887700028 Publication Date 2011-03-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 28 Open Access  
  Notes ; This research was supported by the French Ministry of Culture within the National Program of Research (“La conservation des manuscrits: etude du vieillissement naturel de papiers impregnes d'encres ferrogalliques”). It was funded by grants from HASYLAB (experiments I-20090280 EC and II-20060245 EC) and SOLEIL (proposals 20060396 and 20080761) and was supported by the Interuniversity Attraction Poles Programme Belgian Science Policy (1UAP V1/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects nos. G.0689.06, G.0704.08 and G017909N. We are thankful to Dr. Dominique Thaudiere, Dr. Solenn Reguer, Dr. Andrea Somogyi, Dr. Karen Appel, Dr. Manuela Borchert, and Dr. Gerald Falkenberg for their assistance and help during the experiments performed at SOLEIL beamline “DIFFABS” and at HASYLAB Beam line “L” respectively. ; Approved Most recent IF: 6.32; 2011 IF: 5.856  
  Call Number UA @ admin @ c:irua:89593 Serial 5822  
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