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“Oxidation states of uranium in DU particles from Kosovo”. Salbu B, Janssens K, Lind OC, Proost K, Danesi PR, Journal of environmental radioactivity 64, 167 (2003). http://doi.org/10.1016/S0265-931X(02)00047-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.31
DOI: 10.1016/S0265-931X(02)00047-4
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“Oxidation states of uranium in depleted uranium particles from Kuwait”. Salbu B, Janssens K, Lind OC, Proost K, Gijsels L, Danesi PR, Journal of environmental radioactivity 78, 125 (2004). http://doi.org/10.1016/J.JENVAD.2004.04.001
Abstract: The oxidation states of uranium in depleted uranium (DU) particles were determined by synchrotron radiation based mu-XANES, applied to individual particles isolated from selected samples collected at different sites in Kuwait. Based on scanning electron microscopy with X-ray microanalysis prior to mu-XANES, DU particles ranging from sub-microns to several hundred micrometers were observed. The.median particle size depended on sources and sampling sites; small-sized particles (median 13 mum) were identified in swipes taken from the inside of DU penetrators holes in tanks and in sandy soil collected below DU penetrators, while larger particles (median 44 mum) were associated with fire in a DU ammunition storage facility. Furthermore, the U-236/U-235 ratios obtained from accelerator mass spectrometry demonstrated that uranium in the DU particles originated from reprocessed fuel (about 10(-2) in DU from the ammunition facility, about 10(-3) for DU in swipes). Compared to well-defined standards, all investigated DU particles were oxidized. Uranium particles collected from swipes were characterized as UO2, U3O8 or a mixture of these oxidized forms, similar to that observed in DU affected areas in Kosovo. Uranium particles formed during fire in the DU ammunition facility were, however, present as oxidation state +5 and +6, with XANES spectra similar to solid uranyl standards. Environmental or health impact assessments for areas affected by DU munitions should therefore take into account the presence of respiratory UO2, U3O8 and even UO3 particles, their corresponding weathering rates and the subsequent mobilisation of U from oxidized DU particles. (C) 2004 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.31
DOI: 10.1016/J.JENVAD.2004.04.001
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“Characterization of uranium and plutonium containing particles originating from the nuclear weapons accident in Thule, Greenland, 1968”. Lind OC, Salbu B, Janssens K, Proost K, Dahlgaard H, Journal of environmental radioactivity 81, 21 (2005). http://doi.org/10.1016/J.JENVRAD.2004.10.013
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.31
Times cited: 37
DOI: 10.1016/J.JENVRAD.2004.10.013
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“Solid state speciation and potential bioavailability of depleted uranium particles from Kosovo and Kuwait”. Lind OC, Salbu B, Skipperud L, Janssens K, Jaroszewicz J, de Nolf W, Journal of environmental radioactivity 100, 301 (2009). http://doi.org/10.1016/J.JENVRAD.2008.12.018
Abstract: A combination of synchrotron radiation based X-ray microscopic techniques (ì-XRF, ì-XANES, ì-XRD) applied on single depleted uranium (DU) particles and semi-bulk leaching experiments has been employed to link the potential bioavailability of DU particles to site-specific particle characteristics. The oxidation states and crystallographic forms of U in DU particles have been determined for individual particles isolated from selected samples collected at different sites in Kosovo and Kuwait that were contaminated by DU ammunition during the 1999 Balkan conflict and the 1991 Gulf war. Furthermore, small soil or sand samples heavily contaminated with DU particles were subjected to simulated gastrointestinal fluid (0.16 M HCl) extractions. Characteristics of DU particles in Kosovo soils collected in 2000 and in Kuwait soils collected in 2002 varied significantly depending on the release scenario and to some extent on weathering conditions. Oxidized U (+6) was determined in large, fragile and bright yellow DU particles released during fire at a DU ammunition storage facility and crystalline phases such as schoepite (UO3·2.25H2O), dehydrated schoepite (UO3·0.75H2O) and metaschoepite (UO3·2.0H2O) were identified. As expected, these DU particles were rapidly dissolved in 0.16 M HCl (84 ± 3% extracted after 2 h) indicating a high degree of potential mobility and bioavailability. In contrast, the 2 h extraction of samples contaminated with DU particles originating either from corrosion of unspent DU penetrators or from impacted DU ammunition appeared to be much slower (2030%) as uranium was less oxidized (+4 to +6). Crystalline phases such as UO2, UC and metallic U or UTi alloy were determined in impacted DU particles from Kosovo and Kuwait, while the UO2,34 phase, only determined in particles from Kosovo, could reflect a more corrosive environment. Although the results are based on a limited number of DU particles, they indicate that the structure and extractability of DU particles released from similar sources (metallic U penetrators) will depend on the release scenarios (fire, impact) and to some extent environmental conditions. However, most of the DU particles (7396%) in all investigated samples were dissolved in 0.16 M HCl after one week indicating that a majority of the DU material is bioaccessible.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.31
Times cited: 49
DOI: 10.1016/J.JENVRAD.2008.12.018
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“Micro-analytical characterisation of radioactive heterogeneities in samples from Central Asian TENORM sites”. Lind OC, de Nolf W, Janssens K, Salbu B, Journal of environmental radioactivity 123, 63 (2013). http://doi.org/10.1016/J.JENVRAD.2012.02.012
Abstract: The present work focuses on the use of micro-analytical techniques to demonstrate the heterogeneous distribution of radionuclides and metals in soils collected at Former Soviet Union mining sites in Central Asia. Based on digital autoradiography, radionuclides were heterogeneously distributed in soil samples collected at the abandoned uranium mining sites Kurday, Kazakhstan, Kadji Sai, Kyrgyzstan and Taboshar, Tajikistan. Using electron microscopy interfaced with X-ray microanalysis submicron – mm-sized radioactive particles and rock fragments with U, As, Se and toxic metals on the surfaces were identified in Kurday and Kadji Sai samples. Employing scanning and tomographic (3D) synchrotron radiation based micro-X-ray fluorescence (mu-SRXRF) and synchrotron radiation based micro-X-ray diffraction (mu-SRXRD) allowed us to observe the inner structure of the particles without physical sectioning. The distribution of elements in virtual crosssections demonstrated that U and a series of toxic elements were rather heterogeneously distributed also within individual radioactive TENORM particles. Compared to archived data, U in Kadji Sai particles was present as uraninite (U4O9+y or UO2+x) or Na-zippeite aNa(4)(UO2)(6)[(OH)(10)(SO4)(3)]center dot 4H(2)O), i.e. U minerals with very low solubility. The results suggested that TENORM particles can carry substantial amount of radioactivity, which can be subject to re-suspension, atmospheric transport and water transport. Thus, the potential radioecological and radioanalytical impact of radioactive particles at NORM and TENORM sites worldwide should be taken into account. The present work also demonstrates that radioecological studies should benefit from the use of advanced methods such as synchrotron radiation based techniques. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.31
Times cited: 16
DOI: 10.1016/J.JENVRAD.2012.02.012
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“Micro-analytical characterization of thorium-rich aggregates from Norwegian NORM sites (Fen Complex, Telemark)”. Cagno S, Lind OC, Popic JM, Skipperud L, De Nolf W, Nuyts G, Vanmeert F, Jaroszewicz J, Janssens K, Salbu B, Journal Of Environmental Radioactivity 219, 106273 (2020). http://doi.org/10.1016/J.JENVRAD.2020.106273
Abstract: In this study we performed microscopic characterization of mineral particles that were collected in the thorium-rich Fen Complex in Norway and identified and isolated based on autoradiography in function of their radioactivity. For this we combined information obtained with X-ray absorption mu-CT, mu-XRF and mu-XRD, both in bi- and in three-dimensional (tomographic) mode. We demonstrate that radionuclides and metals are heterogeneously distributed both within soil samples and within individual Th-enriched aggregates, which are characterised as low-density mineral bulk particles with high density material inclusions, where Th as well as several metals are highly concentrated. For these sites, it is important to take into account how these inhomogeneous distributions could affect the overall environmental behaviour of Th and progeny upon weathering due to human or environmental factors. Moreover, the estimated size of the Th-containing inclusions as determined in this work represents information of importance for the characterization of radionuclides and toxic metals exposure, as well as for assessing the viability of mining for Th and rare-earth metals in the Fen Complex and the associated environmental impact.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.3
DOI: 10.1016/J.JENVRAD.2020.106273
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“The dark halo technique in the oeuvre of Michael Sweerts and other Flemish and Dutch baroque painters. A 17th c. empirical solution to mitigate the optical 'simultaneous contrast' effect?”.Derks K, van der Snickt G, Legrand S, van der Stighelen K, Janssens K, Heritage science 10, 5 (2022). http://doi.org/10.1186/S40494-021-00634-W
Abstract: Although the topic is rarely addressed in literature, a significant number of baroque paintings exhibit dark, halo-like shapes around the contours of the dramatis personae. Close examination of both finished and unfinished works suggests that this intriguing feature was a practical tool that helped the artist in the early painting stages. When applying the final brushwork, the halo lost its function, with some artists undertaking efforts to hide it. Although their visibility might not have been intended by the artists, today this dark paint beneath the surface is partially visible through the upper paint layers. Moreover, the disclosure of many halos using infrared photography (IRP), infrared reflectography (IRR) and macro X-ray fluorescence imaging (MA-XRF), additional to those that can be observed visually, suggests that this was a common and established element of 17th-century painting practice in Western Europe. Building on an existing hypothesis, we argue that halos can be considered as a solution to an optical problem that arose when baroque painters reversed the traditional, 15th- and 16th-century painting sequence of working from background to foreground. Instead, they started with the dominant parts of a composition, such as the face of a sitter. In that case, a temporary halo can provide the essential tonal reference to anticipate the chromatic impact of the final dark colored background on the adjacent delicate carnations. In particular, we attempt to clarify the prevalence of dark halos as a response to optical effects such as 'simultaneous contrast' and 'the crispening effect', described in literature only centuries later. As such, the recently termed 'ring condition' can be seen as the present-day equivalent of the 'halo solution' that was seemingly empirically or intuitively developed by 17th-century artists. Modern studies in visual perception proves that by laying a black ring around a target color, the optical impact of a surrounding color can be efficiently neutralized. Finally, by delving into works by Michael Sweerts, it becomes clear that resourceful artists might have adapted the halo technique and the underlying principles to their individual challenges, such as dealing with differently colored grounds.
Keywords: A1 Journal article; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 2.5
DOI: 10.1186/S40494-021-00634-W
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“Chemical composition and deterioration of glass excavated in the 15th-16th century fishermen town of Raversijde (Belgium)”. Schalm O, Caluwé, D, Wouters H, Janssens K, Verhaeghe F, Pieters M, Spectrochimica acta: part A: molecular and biomolecular spectroscopy 59, 1647 (2004). http://doi.org/10.1016/J.SAB.2004.07.012
Abstract: The chemical composition, as determined by electron probe X-ray microanalysis of a series of ca. 100 archaeological glass fragments, excavated at the Raversijde site (Belgium) is discussed. In the 15th-16th century, Raversijde was a flourishing fishermen town located on the shore of the North Sea, close to the city of Ostend. As a consequence of several battles that were fought in its vicinity, the site was abandoned in the 16th century and was not occupied since then. It is one of the rare archaeological sites in Europe that contains a significant amount of information on the daily life inside a small but affluent medieval community. A comparison of the chemical composition of fragments of vessels and window glass encountered in Raversijde to those found in urban centres in Belgium and to literature date on German and French archaeological finds shows that glass made with wood ash dominates. Usually, it concerns artifacts with a predominantly utilitarian use. A few objects made with sodic (i.e., Na-rich) glass were also encountered, likely to have been imported from Venice during the 15th century or in later periods from an urban centre such as Antwerp, where Facon-de-Venice glass manufacturing activities were established near the start of the 16th century. (C) 2004 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.536
Times cited: 26
DOI: 10.1016/J.SAB.2004.07.012
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“Confocal microscopic X-ray fluorescence at the HASYLAB microfocus beamline: characteristics and possibilities”. Janssens K, Proost K, Falkenberg G, Spectrochimica acta: part A: molecular and biomolecular spectroscopy 59, 1637 (2004). http://doi.org/10.1016/J.SAB.2004.07.025
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.536
Times cited: 102
DOI: 10.1016/J.SAB.2004.07.025
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“Editorial”. van Grieken R, Bogaerts A, Janssens K, Spectrochimica acta: part A: molecular spectroscopy 64, 1089 (2006). http://doi.org/10.1016/j.saa.2006.05.011
Keywords: Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.536
DOI: 10.1016/j.saa.2006.05.011
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“Spectroscopic investigation on the chemical forms of Cu during the synthesis of zeolite X at low temperature”. Terzano R, Spagnuolo M, Medici L, Tateo F, Vekemans B, Janssens K, Ruggiero P, Applied geochemistry 21, 993 (2006). http://doi.org/10.1016/J.APGEOCHEM.2006.03.004
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.581
Times cited: 15
DOI: 10.1016/J.APGEOCHEM.2006.03.004
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“LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia”. Cagno S, Hellemans K, Lind OC, Skipperud L, Janssens K, Salbu B, Environmental science : processes &, impacts 16, 306 (2014). http://doi.org/10.1039/C3EM00531C
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.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.592
Times cited: 10
DOI: 10.1039/C3EM00531C
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“Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art”. Al-Emam E, Soenen H, Caen J, Janssens K, Heritage science 8, 106 (2020). http://doi.org/10.1186/S40494-020-00447-3
Abstract: Since cleaning of artworks may cause undesirable physicochemical alterations and is a nonreversible procedure, it is mandatory to adopt the proper cleaning procedure. Such a procedure should remove undesired materials whilst preserving the original surface. In this regard, numerous gels have been developed and exploited for the cleaning of various artwork surfaces. Lately, agarose (AG) and polyvinyl alcohol-borax (PVA-B) hydrogels have been widely employed as cleaning tools by conservators. Both hydrogels show some limitations in specific cleaning practices. In this work, we investigated the influence of including increased levels of agarose into PVA-B systems. For this reason, we performed a detailed characterization on the double network (DN) hydrogel including the chemical structure, the liquid phase retention, the rheological behavior, and the self-healing behavior of various PVA-B/AG double network hydrogels. These new hydrogels revealed better properties than PVA-B hydrogels and obviated their limitations. The inclusion of AG into PVA-B systems enhanced the liquid retention capacity, shape-stability, and mechanical strength of the blend. Furthermore, AG minimized the expelling/syneresis issue that occurs when loading PVA-B systems with low polarity solvents or chelating agents. The resultant double network hydrogel exhibits relevant self-healing properties. The PVA-B/AG double network is a new and useful cleaning tool that can be added to the conservators' tool-kit. It is ideal for cleaning procedures dealing with porous and complex structured surfaces, vertical surfaces and for long time applications.
Keywords: A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
Impact Factor: 2.5
Times cited: 1
DOI: 10.1186/S40494-020-00447-3
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“Formation of zinc oxalate from zinc white in various oil binding media: the influence of atmospheric carbon dioxide by reaction with 13CO2”. Simonsen KP, Poulsen JN, Vanmeert F, Ryhl-Svendsen M, Bendix J, Sanyova J, Janssens K, Mederos-Henry F, Heritage science 8, 126 (2020). http://doi.org/10.1186/S40494-020-00467-Z
Abstract: The formation of metal oxalates in paintings has recently gained a great deal of interest within the field of heritage science as several types of oxalate compounds have been identified in oil paintings. The present work investigates the formation of metal oxalates in linseed oil in the presence of the artists' pigments zinc white, calcite, lead white, zinc yellow, chrome yellow, cadmium yellow, cobalt violet, and verdigris. The oil paint films were artificially photo-aged by exposure to UVA light at low and high relative humidity, and afterwards analysed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The results showed that, compared to the other pigments investigated, zinc white is especially prone to metal oxalate formation and that high humidity is a crucial factor in this process. Consequently, the reactivity and photo-aging of ZnO in various oil binding media was investigated further under simulated solar radiation and at high relative humidity levels. ATR-FTIR showed that zinc oxalate is formed in all oil binding media while X-ray powder diffraction (PXRD) revealed it was mainly present in an amorphous state. To examine whether atmospheric CO2(g) has any influence on the formation of zinc oxalate, experiments with isotopically enriched (CO2(g))-C-13 were performed. Based on ATR-FTIR measurements, neither (ZnC2O4)-C-13 nor (ZnCO3)-C-13 were formed which suggests that the carbon source for the oxalate formation is most likely the paint itself (and its oil component) and not the surrounding atmosphere.
Keywords: A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.5
DOI: 10.1186/S40494-020-00467-Z
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“The role of smalt in complex pigment mixtures in Rembrandt'sHomer1663: combining MA-XRF imaging, microanalysis, paint reconstructions and OCT”. van Loon A, Noble P, de Man D, Alfeld M, Callewaert T, van der Snickt G, Janssens K, Dik J, Heritage science 8, 90 (2020). http://doi.org/10.1186/S40494-020-00429-5
Abstract: As part of the NWO Science4ArtsREVISRembrandtproject (2012-2018), novel chemical imaging techniques were developed and applied to the study of Rembrandt's late experimental painting technique (1651-1669). One of the unique features in his late paintings is his abundant use of smalt: a blue cobalt glass pigment that he often combined with organic lake pigments, earth pigments and blacks. Since most of these smalt-containing paints have discolored over time, we wanted to find out more about how these paintings may have originally looked, and what the role of smalt was in his paint. This paper reports on the use of smalt in complex pigment mixtures in Rembrandt'sHomer(1663), Mauritshuis, The Hague. Macroscopic X-ray fluorescence imaging (MA-XRF) assisted by computational analysis, in combination with SEM-EDX analysis of paint cross-sections, provides new information about the distribution and composition of the smalt paints in the painting. Paint reconstructions were carried out to investigate the effect of different percentages of smalt on the overall color, the drying properties, translucency and texture of the paint. Results show that the influence of (the originally blue) smalt on the intended color of the paint of theHomeris minimal. However, in mixtures with high percentages of smalt, or when combined with more transparent pigments, it was concluded that the smalt did produce a cooler and darker paint. It was also found that the admixture of opaque pigments reduced the translucent character of the smalt. The drying tests show that the paints with (cobalt-containing) smalt dried five times faster compared to those with glass (without cobalt). Most significantly, the texture of the paint was strongly influenced by adding smalt, creating a more irregular surface topography with clearly pronounced brushstrokes. Optical coherence tomography (OCT) was used as an additional tool to reveal differences in translucency and texture between the different paint reconstructions. In conclusion, this study confirmed earlier assumptions that Rembrandt used substantial amounts of smalt in his late paintings, not for its blue color, but to give volume and texture to his paints, to deepen their colors and to make them dry faster.
Keywords: A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
Impact Factor: 2.5
DOI: 10.1186/S40494-020-00429-5
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“Towards a novel strategy for soot removal from water-soluble materials : the synergetic effect of hydrogels and cyclomethicone on gelatine emulsion-based photographs”. Ortega Saez N, Arno R, Marchetti A, Cauberghs S, Janssens K, Van der Snickt G, Al-Emam E, Heritage science 11, 78 (2023). http://doi.org/10.1186/S40494-023-00916-5
Abstract: Gels are a popular cleaning method for paper conservators and a lot of research has been done concerning gel cleaning of paper objects over the last 15 years. Despite the close interconnection between the conservation fields of paper and photographic material, research on using gels for cleaning photographs is very scarce. However, gels can provide an excellent cleaning method for photographic material. Cleaning silver gelatine prints with aqueous solvents is very complex due to the hydrophilic properties and fragility of the gelatine layer which makes mechanical cleaning difficult. The properties of gels ensure better control over the flow and evaporation of the solvent, facilitating the cleaning process. This study is the first insight into the viability of using gellan gum gel and polyvinyl acetate-borax (PVAc-borax) gel to clean contaminants from the surface of silver gelatine photographs. It is based on self-made samples that were artificially aged and contaminated with soot. Water, ethanol (EtOH), and Kodak Photo-flo were studied as solvents to remove the soot from the silver gelatine-based prints. These solvents were loaded into the aforementioned gels and applied to the samples in two different methods. These gel cleaning methods were subsequently compared with traditional cleaning methods. In addition, the usage of cyclomethicone D4 as a protective mask for the gelatine layer was studied. Measuring methods used to evaluate the cleaning were visual comparison, microscopic observation, and densitometry. ATR-FTIR measurements were also conducted to investigate potential side-effects of the cleaning methods on the prints, such as unwanted chemical transformations or the presence of gel residues after the treatments. Most of the gel cleaning methods within this study proved to be inadequate, with the exception of the gellan gum gel loaded with 30% EtOH. It was used as a granulated gel applied mechanically on a print saturated with cyclomethicone (octamethylcyclotetrasiloxane D4). Cyclomethicone proved to be a very effective protective barrier for the water-sensitive gelatine layer with minimal reduction in cleaning effectiveness.
Keywords: A1 Journal article; Engineering sciences. Technology; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 2.5
DOI: 10.1186/S40494-023-00916-5
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“Trace-level microanalysis of Roman glass from Khirbet Qumran, Israel”. Aerts A, Janssens K, Adams F, Journal of archaeological science 26, 883 (1999). http://doi.org/10.1006/JASC.1999.0397
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
DOI: 10.1006/JASC.1999.0397
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“Raw materials for medieval to post-medieval Tuscan glassmaking : new insight from LA-ICP-MS analyses”. Cagno S, Mendera M, Jeffries T, Janssens K, Journal of archaeological science 37, 3030 (2010). http://doi.org/10.1016/J.JAS.2010.06.030
Abstract: LA-ICP-MS analyses were performed on a set of Tuscan (post) medieval archaeological glass finds dated to the 1316th century in order to quantitatively determine the trace element contents. The results are used for defining and distinguishing several compositional groups. The trace element data are consistent with the distinctions obtained by considering the major element data determined via quantitative SEM-EDX, but allow to obtain new insights into the nature and quality of the silica sources employed and the presumed method of ash purification.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 38
DOI: 10.1016/J.JAS.2010.06.030
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“Optical spectroscopy as a rapid and low-cost tool for the first-line analysis of glass artefacts : a step-by-step plan for Roman green glass”. Meulebroeck W, Cosyns P, Baert K, Wouters H, Cagno S, Janssens K, Terryn H, Nys K, Thienpont H, Journal of archaeological science 38, 2387 (2011). http://doi.org/10.1016/J.JAS.2011.04.023
Abstract: Archaeometric research on glass artefacts is continuously evolving and is converging towards a multidisciplinary research domain where different types of techniques are applied depending on the questions asked and the circumstances involved. The technique described in this work is optical spectroscopy. The benefit of this technique being the possibility of building up a knowledge database for a large amount of material in a relatively short period of time and with a relatively limited budget. This is of particular interest for the investigation of extensive and/or unexplored glass collections where a first-line analysis of artefacts could facilitate the selection of material needing further and more detailed examination. This publication explores the extent to which optical spectroscopy can be used for a first-line analysis of green coloured glass artefacts from the Roman period. It is shown that the colour coordinates calculated from the measured transmission spectrum could reveal information about the fragment under study. In particular it is shown that 1) based on the position of the calculated colour values on the colour diagram (CIE1931) one could easily know whether the artefact was coloured using only iron or if copper oxides were also present. In the case of the artefact owing its colour solely to the presence of iron, the distance between the measured colour values and the colour diagrams white point can roughly indicate the iron concentration of the sample; 2) artefacts that were fabricated under similar furnace conditions can also be identified on the colour diagram; 3) samples with identical compositions and fabrication conditions but with different sample thickness, gave rise to a variation in the colour coordinates, thus allowing optical spectroscopy to help identify fragments which might belong to the same object.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 18
DOI: 10.1016/J.JAS.2011.04.023
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“Evidence of early medieval soda ash glass in the archaeological site of San Genesio (Tuscany)”. Cagno S, Favaretto L, Mendera M, Izmer A, Vanhaecke F, Janssens K, Journal of archaeological science 39, 1540 (2012). http://doi.org/10.1016/J.JAS.2011.12.031
Abstract: The early medieval period marks an important turning point in the history of glassmaking, since it comprises the transition period between the mineral-based silica-soda-lime glass of the Roman tradition and the plant ash-based glass. With the aim of expanding the knowledge on the glass recipes and technologies of this period, 37 glass samples were analyzed, originating from the archaeological excavations of San Genesio (Tuscany) and dated from the fourth to the eleventh century. The major and minor element concentrations were measured with SEM-EDX, while the trace elements were quantified with LA-ICP-MS. The results were compared with published compositions of glass samples of similar age in order to highlight differences and similarities. The results offer a very interesting view on the glass circulation in the religious/residential/manufacturing center of San Genesio in the early medieval period. Most of the glass has a typical late-Roman composition, but some glass fragments are identified as soda ash glass. These are among the earliest medieval ash-fluxed glasses ever found in the Italian peninsula. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 24
DOI: 10.1016/J.JAS.2011.12.031
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“Study of medieval glass fragments from Savona (Italy) and their relation with the glass produced in Altare”. Cagno S, Badano MB, Mathis F, Strivay D, Janssens K, Journal of archaeological science 39, 2191 (2012). http://doi.org/10.1016/J.JAS.2012.03.013
Abstract: Altare was in the medieval and post-medieval period an important glassmaking center in the Liguria region in Northern Italy. The first historical evidence of glassmaking in Altare is dated to the twelfth century. In spite of that, due to the continuity of glassmaking up to the present time and the contemporaneous intensive urbanization of the territory, no medieval glass from Altare or its immediate vicinity has been analyzed up to now. In this work, glass from archaeological excavations in the center of Savona, city with close ties with the glassmaking center, was studied. Glass fragments, dated from the tenth to the sixteenth century were selected from the collections of the Archaeological Museum in Savona and non-destructively analyzed with quantitative PIXE-PIGE. The resulting compositions, compared with known glass productions of the same time and evaluated on the basis of historical documents, offer an interesting panorama on the variety of glass circulation in Liguria. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 21
DOI: 10.1016/J.JAS.2012.03.013
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“Composition and state of alteration of 18th-century glass finds found at the Cistercian nunnery of Clairefontaine, Belgium”. Hellemans K, Vincke A, Cagno S, Herremans D, De Clercq W, Janssens K, Journal of archaeological science 47, 121 (2014). http://doi.org/10.1016/J.JAS.2014.03.039
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.
Keywords: A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 12
DOI: 10.1016/J.JAS.2014.03.039
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“Deeply colored and black-appearing Roman glass : a continued research”. Cagno S, Cosyns P, Izmer A, Vanhaecke F, Nys K, Janssens K, Journal of archaeological science 42, 128 (2014). http://doi.org/10.1016/J.JAS.2013.11.003
Abstract: In the context of archaeological and historical assessment of Roman black-appearing glass, the chemical and physical characterization of a large collection of samples originating from various areas of the Roman Empire has been gathered over the past years to (i) verify whether a minor segment of the overall Roman glass production can help in determining possible diachronic changes in Roman imperial glass production (1st century AD – 5th century AD) and (ii) reveal regional compositional differences. In this paper, the latest results on the chemical composition of an additional 44 black-appearing Roman glass samples are presented, together with general conclusions based upon the entire compositional dataset of over 400 analyzed black glass samples. The results show that the Roman black glass is obtained through several glass compositions with a specific chronological, geographical and typological distribution. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 18
DOI: 10.1016/J.JAS.2013.11.003
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“Recent advances in analysis of trace elements in environmental samples by X-ray based techniques (IUPAC Technical Report)”. Terzano R, Denecke MA, Falkenberg G, Miller B, Paterson D, Janssens K, Pure and applied chemistry 91, 1029 (2019). http://doi.org/10.1515/PAC-2018-0605
Abstract: Trace elements analysis is a fundamental challenge in environmental sciences. Scientists measure trace elements in environmental media in order to assess the quality and safety of ecosystems and to quantify the burden of anthropogenic pollution. Among the available analytical techniques, X-ray based methods are particularly powerful, as they can quantify trace elements in situ. Chemical extraction is not required, as is the case for many other analytical techniques. In the last few years, the potential for X-ray techniques to be applied in the environmental sciences has dramatically increased due to developments in laboratory instruments and synchrotron radiation facilities with improved sensitivity and spatial resolution. In this report, we summarize the principles of the X-ray based analytical techniques most frequently employed to study trace elements in environmental samples. We report on the most recent developments in laboratory and synchrotron techniques, as well as advances in instrumentation, with a special attention on X-ray sources, detectors, and optics. Lastly, we inform readers on recent applications of X-ray based analysis to different environmental matrices, such as soil, sediments, waters, wastes, living organisms, geological samples, and atmospheric particulate, and we report examples of sample preparation.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.626
Times cited: 3
DOI: 10.1515/PAC-2018-0605
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“Cluster analysis of IR thermography data for differentiating glass types in historical leaded-glass windows”. Hillen M, Legrand S, Dirkx Y, Janssens K, van der Snickt G, Caen J, Steenackers G, Applied Sciences-Basel 10, 4255 (2020). http://doi.org/10.3390/APP10124255
Abstract: Infrared thermography is a fast, non-destructive and contactless testing technique which is increasingly used in heritage science. The aim of this study was to assess the ability of infrared thermography, in combination with a data clustering approach, to differentiate between the different types of historical glass that were included in a colorless leaded-glass windows during previous restoration interventions. Inspection of the thermograms and the application of two data mining techniques on the thermal data, i.e., k-means clustering and hierarchical clustering, allowed identifying different groups of window panes that show a different thermal behavior. Both clustering approaches arrive at similar groupings of the glass with a clear separation of three types. However, the lead cames that hold the glass panes appear to have a substantial impact on the thermal behavior of the surrounding glass, thus preventing classification of the smallest glass panes. For the larger panes, this was not a critical issue as the center of the glass remained unaffected. Subtle visual color differences between panes, implying a variation in coloring metal ions, was not always distinguished by IRT. Nevertheless, data clustering assisted infrared thermography shows potential as an efficient and swift method for documenting the material intervention history of leaded-glass windows during or in preparation of conservation treatments.
Keywords: A1 Journal article; Engineering sciences. Technology; Antwerp Cultural Heritage Sciences (ARCHES); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.7
DOI: 10.3390/APP10124255
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“Qualitative Comparison of Lock-in Thermography (LIT) and Pulse Phase Thermography (PPT) in Mid-Wave and Long-Wave Infrared for the Inspection of Paintings”. Hillen M, Sels S, Ribbens B, Verspeek S, Janssens K, Van der Snickt G, Steenackers G, Applied Sciences 13, 1 (2023). http://doi.org/10.3390/APP13074094
Abstract: When studying paintings with active infrared thermography (IRT), minimizing the temperature fluctuations and thermal shock during a measurement becomes important. Under these conditions, it might be beneficial to use lock-in thermography instead of the conventionally used pulse thermography (PT). This study compared the observations made with lock-in thermography (LIT) and pulse phase thermography (PPT) with halogen light excitation. Three distinctly different paintings were examined. The LIT measurements caused smaller temperature fluctuations and, overall, the phase images appeared to have a higher contrast and less noise. However, in the PPT phase images, the upper paint layer was less visible, an aspect which is of particular interest when trying to observe subsurface defects or the structure of the support. The influence of the spectral range of the cameras on the results was also investigated. All measurements were taken with a mid-wave infrared (MWIR) and long wave infrared (LWIR) camera. The results show that there is a significant number of direct reflection artifacts, caused by the use of the halogen light sources when using the MWIR camera. Adding a long-pass filter to the MWIR camera eliminated most of these artifacts. All results are presented in a side-by-side comparison.
Keywords: A1 Journal article; Engineering sciences. Technology; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 2.7
DOI: 10.3390/APP13074094
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“In vitro validation of a mobile Raman-XRF micro-analytical instrument's capabilities on the diagnosis of Byzantine icons”. Andrikopoulos KS, Daniilia S, Roussel B, Janssens K, Journal of Raman spectroscopy 37, 1026 (2006). http://doi.org/10.1002/JRS.1612
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.969
Times cited: 53
DOI: 10.1002/JRS.1612
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“Micro-Raman analysis for the identification of pigments from 19th and 20th century paintings”. Aibéo CL, Goffin S, Schalm O, van der Snickt G, Laquière N, Eyskens P, Janssens K, Journal of Raman spectroscopy 39, 1091 (2008). http://doi.org/10.1002/JRS.1990
Abstract: In this article, results using confocal µ-Raman to analyse the cross-section of paint samples are presented. Results obtained with light microscopy, scanning electron microscopy (SEM) combined with an energy dispersive X-ray analysis (EDX) and micro-X-ray fluorescence (µ-XRF) are mentioned and compared to the ones obtained with confocal (MRS). In some cases, pigment identification was possible only by combining analytical results from different techniques. The samples were drawn from five paintings belonging to the Academy of Fine Arts of Antwerp, which are part of a collection of 34 paintings made by students from the Academy between 1819 and 1920. Since, on the one hand, the painting techniques and materials, especially pigments, used in this period are still not completely known, and on the other hand, this collection constitutes a very important and reliable resource of information, these paintings were chosen for a systematic investigation. They represent the evolution of painting in Belgium over approximately a century.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.969
Times cited: 28
DOI: 10.1002/JRS.1990
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“Raman study of different crystalline forms of PbCrO4 and PbCr1-xSxO4 solid solutions for the noninvasive identification of chrome yellows in paintings : a focus on works by Vincent van Gogh”. Monico L, Janssens K, Hendriks E, Brunetti BG, Miliani C, Journal of Raman spectroscopy 45, 1034 (2014). http://doi.org/10.1002/JRS.4548
Abstract: Chrome yellows, a class of pigments frequently used by painters of the Impressionism and Post-impressionism period, are known for their different chemical stability; the latter depends on the chemical composition (PbCrO4, PbCr1-xSxO4) and crystalline structure (monoclinic or orthorhombic) of the material. The possibility to distinguish among different forms of this pigment is therefore relevant in order to extend knowledge on the corresponding degradation process that is observed on several original paintings. For this purpose, three paintings conserved at the Van Gogh Museum (Amsterdam) were analyzed using noninvasive Raman spectroscopy, while equivalent investigations employing bench-top instrumentation were performed to obtain information from micro-samples originating from these works of art. In each painting, the chrome yellow was identified either as monoclinic PbCrO4 or in the form of monoclinic PbCr1-xSxO4 (x<0.25) or S-rich orthorhombic PbCr1-xSxO4 (x similar to 0.5). Our ability to make this fairly subtle distinction is based on a Raman study of several oil paint model samples made up of monoclinic and/or orthorhombic crystalline forms of PbCrO4 and PbCr1-xSxO4 (0.1x0.8). These paints were studied using several excitation wavelengths (namely 785.0, 532.0, 514.5, and 488nm). Because of the absence of the resonance Raman effect, which strongly enhances the chromate symmetric stretching band, and the absence of any laser-induced photodecomposition, it is advantageous to acquire data at 785.0nm. The band-shape and the position of the chromate bending modes proved to be more sensitive to the solid solution composition and crystalline structure than the stretching modes and can be used as distinctive spectral markers to discriminate among the different chrome yellow forms that are present. Copyright (c) 2014 John Wiley & Sons, Ltd.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.969
Times cited: 34
DOI: 10.1002/JRS.4548
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“Photon-based techniques for nondestructive subsurface analysis of painted cultural heritage artifacts”. Janssens K, Dik J, Cotte M, Susini J, Accounts of chemical research 43, 814 (2010). http://doi.org/10.1021/AR900248E
Abstract: Often, just micrometers below a paintings surface lies a wealth of information, both with Old Masters such as Peter Paul Rubens and Rembrandt van Rijn and with more recent artists of great renown such as Vincent Van Gogh and James Ensor. Subsurface layers may include underdrawing, underpainting, and alterations, and in a growing number of cases conservators have discovered abandoned compositions on paintings, illustrating artists practice of reusing a canvas or panel. The standard methods for studying the inner structure of cultural heritage (CH) artifacts are infrared reflectography and X-ray radiography, techniques that are optionally complemented with the microscopic analysis of cross-sectioned samples. These methods have limitations, but recently, a number of fundamentally new approaches for fully imaging the buildup of hidden paint layers and other complex three-dimensional (3D) substructures have been put into practice. In this Account, we discuss these developments and their recent practical application with CH artifacts. We begin with a tabular summary of 14 IR- and X-ray-based imaging methods and then continue with a discussion of each technique, illustrating CH applications with specific case studies. X-ray-based tomographic and laminographic techniques can be used to generate 3D renditions of artifacts of varying dimensions. These methods are proving invaluable for exploring inner structures, identifying the conservation state, and postulating the original manufacturing technology of metallic and other sculptures. In the analysis of paint layers, terahertz time-domain spectroscopy (THz-TDS) can highlight interfaces between layers in a stratigraphic buildup, whereas macrosopic scanning X-ray fluorescence (MA-XRF) has been employed to measure the distribution of pigments within these layers. This combination of innovative methods provides topographic and color information about the micrometer depth scale, allowing us to look into paintings in an entirely new manner. Over the past five years, several new variants of traditional IR- and X-ray-based imaging methods have been implemented by conservators and museums, and the first reports have begun to emerge in the primary research literature. Applying these state-of-the-art techniques in a complementary fashion affords a more comprehensive view of paintings and other artworks.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 20.268
Times cited: 78
DOI: 10.1021/AR900248E
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