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Author (down) Almohammadi, G.; O'Modhrain, C.; Kelly, S.; Sullivan, J.A.
Title Ti-doped SBA-15 catalysts used in phenol oxidation reactions Type A1 Journal article
Year 2020 Publication ACS Omega Abbreviated Journal
Volume 5 Issue 1 Pages 791-798
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Two Ti-SBA-15 catalysts are synthesized using techniques that should either deposit Ti atoms specifically at the SBA-15 surface or allow Ti-containing species to exist at both the surface and within the bulk of SBA-15. The materials have been characterized by Fourier transform infrared (FTIR), Raman and UV visible spectroscopies, transmission electron microscopy, scanning electron microscopy/energy-dispersive X-ray spectrometry microscopies, and N-2 physisorption experiments. They have been applied in the total oxidation of phenol under catalytic wet air oxidation (CWAO) conditions and using photo- and plasma promotion. The materials retain the structure of SBA-15 following the doping in both cases and Ti incorporation is confirmed. The nature of the incorporated Ti remains unclear-with evidence for anatase TiO2 (from Raman and UV vis analysis) and evidence for atomically dispersed Ti from FTIR. In terms of reactivity, the presence of Ti in the in situ-prepared catalyst improves reactivity in the photopromoted reaction (increasing conversion from 28 to 60%), while both Ti catalysts improve reactivity in the CWAO reaction (by 7% over the in situ catalyst and by 25% over the grafted material). The presence of Ti has no beneficial effect on conversion in the plasma-promoted reaction. Here, however, Ti does affect the nature of the oxidized intermediates formed during the total phenol oxidation.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000507578300086 Publication Date 2019-12-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-1343 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.1 Times cited Open Access
Notes ; The KSA Ministry of Higher Education is acknowledged for providing G.A.'s studentship, and IRC funded the plasma work under grant ref: GOIPD/2017/1000. ; Approved Most recent IF: 4.1; 2020 IF: NA
Call Number UA @ admin @ c:irua:166578 Serial 6629
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Author (down) Almabadi, M.H.; Truta, F.M.; Adamu, G.; Cowen, T.; Tertis, M.; Alanazi, K.D.M.; Stefan, M.-G.; Piletska, E.; Kiss, B.; Cristea, C.; De Wael, K.; Piletsky, S.A.; Cruz, A.G.
Title Integration of smart nanomaterials for highly selective disposable sensors and their forensic applications in amphetamine determination Type A1 Journal article
Year 2023 Publication Electrochimica acta Abbreviated Journal
Volume 446 Issue Pages 142009-142010
Keywords A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract Screening drugs on the street and biological samples pose a challenge to law enforcement agencies due to existing detection methods and instrument limitations. Herein we present a graphene-assisted molecularly imprinted polymer nanoparticle-based sensor for amphetamine. These nanoparticles are electroactive by incorporating ferrocene in their structure. These particles act as specific actuators in electrochemical sensors, and the presence of a ferrocene redox probe embedded in the structure allows the detection of non-electroactive amphetamine. In a control approach, nanoparticles were covalently immobilised onto electrochemical sensors by drop-casting using silanes. Alternatively, nanoparticles were immobilised employing 3D printing and a graphene ink composite. The electrochemical performance of both approaches was evaluated. As a result, 3D printed nanoMIPs/graphene sensors displayed the highest selectivity in spiked human plasma, with sensitivity at 73 nA nM-1, LOD of 68 nM (RSD 2.4%) when compared to the silane drop cast electrodes. The main advantage of the optimised 3D printing technology is that it allows quantitative determination of amphetamine, a nonelectroactive drug, challenging to detect with conventional electrochemical sensors. In addition, the costefficient 3D printing method makes these sensors easy to manufacture, leading to robust, highly selective and sensitive sensors. As proof of concept, sensors were evaluated on the street specimens and clinically relevant samples and successfully validated using UPLC-MS.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000953087600001 Publication Date 2023-02-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-4686 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.6 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.6; 2023 IF: 4.798
Call Number UA @ admin @ c:irua:196145 Serial 8888
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Author (down) Alloul, A.; Wuyts, S.; Lebeer, S.; Vlaeminck, S.E.
Title Volatile fatty acids impacting phototrophic growth kinetics of purple bacteria : paving the way for protein production on fermented wastewater Type A1 Journal article
Year 2019 Publication Water research Abbreviated Journal
Volume 152 Issue Pages 138-147
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Nutrient losses in our food chain severely surpass our planetary boundaries. Resource recovery can contribute to mitigation, for instance through converting wastewater resources to microbial protein for animal feed. Wastewater typically holds a complex mixture of organics, posing a challenge to selectively produce heterotrophic biomass. Ensuring the product's quality could be achieved by anaerobic generation of volatile fatty acids (VFAs) followed by photoheterotrophic production of purple non-sulfur bacteria (PNSB) with infrared light. This study aimed to determine the most suitable PNSB culture for VFA conversion and map the effect of acetate, propionate, butyrate and a VFA mixture on growth and biomass yield. Six cultures were screened in batch: (i) Rhodopseudomonas palustris, (ii) Rhodobacter sphaeroides, (iii) Rhodospirillum rubrum, (iv) a 3-species synthetic community (i+ii+iii), (v) a community enriched on VFA holding Rb. capsulatus, and (vi) Rb. capsulatus (isolate v). The VFA mixture elevated growth rates with a factor 1.32.5 compared to individual VFA. Rb. capsulatus showed the highest growth rates: 1.82.2 d−1 (enriched) and 2.33.8 d−1 (isolated). In a photobioreactor (PBR) inoculated with the Rb. capsulatus enrichment, decreasing sludge retention time (SRT) yielded lower biomass concentrations, yet increased productivities, reaching 1.7 g dry weight (DW) L−1 d−1, the highest phototrophic rate reported thus far, and a growth rate of up to 5 d−1. PNSB represented 2657% of the community and the diversity index was low (37), with a dominance of Rhodopseudomonas at long SRT and Rhodobacter at short SRT. The biomass yield for all cultures, in batch and reactor cultivation, approached 1 g CODBiomass g−1 CODRemoved. An economic estimation for a two-stage approach on brewery wastewater (load 2427 kg COD d−1) showed that 0.5 d SRT allowed for the lowest production cost ( 10 kg−1 DW; equal shares for capex and opex). The findings strengthen the potential for a novel two-stage approach for resource recovery from industrial wastewater, enabling high-rate PNSB production.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000458223900013 Publication Date 2018-12-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0043-1354; 1879-2448 ISBN 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:156462 Serial 8739
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Author (down) Alloul, A.; Wille, M.; Lucenti, P.; Bossier, P.; Van Stappen, G.; Vlaeminck, S.E.
Title Purple bacteria as added-value protein ingredient in shrimp feed : Penaeus vannamei growth performance, and tolerance against Vibrio and ammonia stress Type A1 Journal article
Year 2021 Publication Aquaculture Abbreviated Journal Aquaculture
Volume 530 Issue Pages 735788
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Aquafeeds contain protein ingredients such as fishmeal and soybean meal, yet their production puts pressure on the environment. Finding novel protein sources such as dried microbial biomass produced on recovered or renewable resources, so-called single-cell protein or microbial protein, can contribute to a more sustainable aquaculture industry. New microbial protein sources are emerging with photoheterotrophic grown purple non‑sulfur bacteria (PNSB) showing high potential, yet research of PNSB as added-value protein ingredient is limited. This research studied their use as a protein source for the white leg shrimp (Penaeus vannamei) and investigated the shrimp's tolerance against Vibrio and ammonia stress. A 28-day shrimp feeding trial was performed with a commercial formulation without PNSB as experimental control (diet i), two pure PNSB species, namely Rhodopseudomonas palustris (diets ii-iii), Rhodobacter capsulatus (diets iv-v) at two protein inclusion levels of 5 and 11 g PNSBprotein 100 g−1 feedprotein and a PNSB enriched culture at a protein inclusion level of 11 g PNSBprotein 100 g−1 feedprotein (diet vi). For the shrimp fed with Rb. capsulatus, 5–25% higher individual weights (p < .05) and better feed conversion ratios were observed relative to the commercial diet (1.3–1.4 vs. control 1.7 g feed g−1 biomass; p < .05). The diet containing Rps. palustris at 5 g PNSBprotein 100 g−1 feedprotein inclusion also showed higher individual weights (26%, p < .05) and a better feed conversion ratio compared to the commercial feed (1.3 vs. control 1.7 g feed g−1 biomass; p < .05). The challenge test subsequent to the feeding trial showed a higher tolerance against ammonia (3 mg N L−1) for shrimp fed with Rps. palustris (survival 63–75% vs. 8% commercial diet; p < .05). For a post-feeding challenge test with Vibrio parahaemolyticus TW01, mortality rates were equal among all treatments. Yet, in vitro tests in 96-Well plates and agar spot assays showed that the PNSB species (i) Rps. palustris, (ii) Rb. capsulatus, (iii) Rb. sphaeroides, (iv) Rhodospirillum rubrum and (v) Afifella marina suppressed the pathogens V. parahaemolyticus TW01 and V. campbellii LMG 21363. Overall, this study demonstrated the potential of PNSB as an added-value protein ingredient in shrimp nursery feed. This can contribute to a circular economy, as PNSB can be cultivated on recovered or renewable resources (e.g. wastewater).
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000582169700073 Publication Date 2020-08-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0044-8486 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.57 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.57
Call Number UA @ admin @ c:irua:170549 Serial 8429
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Author (down) Alloul, A.; Vlaeminck, S.E.
Title Towards upgrading of wastewater resources to microbial protein : volatile fatty acids impacting growth kinetics and yield of purple bacteria Type P3 Proceeding
Year 2017 Publication Abbreviated Journal
Volume Issue Pages 2 p. T2 - 5th IWA Benelux Young Water Professional
Keywords P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
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:151115 Serial 8683
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Author (down) Alloul, A.; Van Kampen, W.; Cerruti, M.; Wittouck, S.; Pabst, M.; Weissbrodt, D.G.
Title Exploring the role of antimicrobials in the selective growth of purple phototrophic bacteria through genome mining and agar spot assays Type A1 Journal article
Year 2022 Publication Letters in applied microbiology Abbreviated Journal Lett Appl Microbiol
Volume 75 Issue 5 Pages 1275-1285
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Purple non-sulphur bacteria (PNSB) are an emerging group of microbes attractive for applied microbiology applications such as wastewater treatment, plant biostimulants, microbial protein, polyhydroxyalkanoates and H-2 production. These photoorganoheterotrophic microbes have the unique ability to grow selectively on organic carbon in anaerobic photobioreactors. This so-called selectivity implies that the microbial community will have a low diversity and a high abundance of a particular PNSB species. Recently, it has been shown that certain PNSB strains can produce antimicrobials, yet it remains unclear whether these contribute to competitive inhibition. This research aimed to understand which type of antimicrobial PNSB produce and identify whether these compounds contribute to their selective growth. Mining 166 publicly-available PNSB genomes using the computational tool BAGEL showed that 59% contained antimicrobial encoding regions, more specifically biosynthetic clusters of bacteriocins and non-ribosomal peptide synthetases. Inter- and intra-species inhibition was observed in agar spot assays for Rhodobacter blasticus EBR2 and Rhodopseudomonas palustris EBE1 with inhibition zones of, respectively, 5.1 and 1.5-5.7 mm. Peptidomic analysis detected a peptide fragment in the supernatant (SVLQLLR) that had a 100% percentage identity match with a known non-ribosomal peptide synthetase with antimicrobial activity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000837055500001 Publication Date 2022-07-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0266-8254 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.4 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.4
Call Number UA @ admin @ c:irua:189519 Serial 7162
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Author (down) Alloul, A.; Spanoghe, J.; Machado, D.; Vlaeminck, S.E.
Title Unlocking the genomic potential of aerobes and phototrophs for the production of nutritious and palatable microbial food without arable land or fossil fuels Type A1 Journal article
Year 2022 Publication Microbial biotechnology Abbreviated Journal
Volume 15 Issue 1 Pages 6-12
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The increasing world population and living standards urgently necessitate the transition towards a sustainable food system. One solution is microbial protein, i.e. using microbial biomass as alternative protein source for human nutrition, particularly based on renewable electron and carbon sources that do not require arable land. Upcoming green electrification and carbon capture initiatives enable this, yielding new routes to H2, CO2 and CO2-derived compounds like methane, methanol, formic- and acetic acid. Aerobic hydrogenotrophs, methylotrophs, acetotrophs and microalgae are the usual suspects for nutritious and palatable biomass production on these compounds. Interestingly, these compounds are largely un(der)explored for purple non-sulfur bacteria, even though these microbes may be suitable for growing aerobically and phototrophically on these substrates. Currently, selecting the best strains, metabolisms and cultivation conditions for nutritious and palatable microbial food mainly starts from empirical growth experiments, and mostly does not stretch beyond bulk protein. We propose a more target-driven and efficient approach starting from the genome-embedded potential to tuning towards, for instance, essential amino- and fatty acids, vitamins, taste,... Genome-scale metabolic models combined with flux balance analysis will facilitate this, narrowing down experimental variations and enabling to get the most out of the 'best' combinations of strain and electron and carbon sources.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000613868600001 Publication Date 2021-02-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1751-7915 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 5.7
Call Number UA @ admin @ c:irua:176174 Serial 7225
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Author (down) Alloul, A.; Muys, M.; Hertoghs, N.; Kerckhof, F.-M.; Vlaeminck, S.E.
Title Cocultivating aerobic heterotrophs and purple bacteria for microbial protein in sequential photo- and chemotrophic reactors Type A1 Journal article
Year 2021 Publication Bioresource Technology Abbreviated Journal Bioresource Technol
Volume 319 Issue Pages 124192
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Aerobic heterotrophic bacteria (AHB) and purple non-sulfur bacteria (PNSB) are typically explored as two separate types of microbial protein, yet their properties as respectively a bulk and added-value feed ingredient make them appealing for combined use. The feasibility of cocultivation in a sequential photo- and chemotrophic approach was investigated. First, mapping the chemotrophic growth kinetics for four Rhodobacter, Rhodopseudomonas and Rhodospirillum species on different carbon sources showed a preference for fructose (µmax 2.4–3.9 d−1 28 °C; protein 36–59%DW). Secondly, a continuous photobioreactor inoculated with Rhodobacter capsulatus (VFA as C-source) delivered the starter culture for an aerobic batch reactor (fructose as C-source). This two-stage system showed an improved nutritional quality compared to AHB production: higher protein content (45–71%DW), more attractive amino/fatty acid profile and contained up to 10% PNSB. The findings strengthen protein production with cocultures and might enable the implementation of the technology for resource recovery on streams such as wastewater.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000613136600013 Publication Date 2020-09-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-8524 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.651 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 5.651
Call Number UA @ admin @ c:irua:171766 Serial 7677
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Author (down) Alloul, A.; Moradvandi, A.; Puyol, D.; Molina, R.; Gardella, G.; Vlaeminck, S.E.; De Schutter, B.; Abraham, E.; Lindeboom, R.E.F.; Weissbrodt, D.G.
Title A novel mechanistic modelling approach for microbial selection dynamics : towards improved design and control of raceway reactors for purple bacteria Type A1 Journal article
Year 2023 Publication Bioresource technology Abbreviated Journal
Volume 390 Issue Pages 129844-129849
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Purple phototrophic bacteria (PPB) show an underexplored potential for resource recovery from wastewater. Raceway reactors offer a more affordable full-scale solution on wastewater and enable useful additional aerobic processes. Current mathematical models of PPB systems provide useful mechanistic insights, but do not represent the full metabolic versatility of PPB and thus require further advancement to simulate the process for technology development and control. In this study, a new modelling approach for PPB that integrates the photoheterotrophic, and both anaerobic and aerobic chemoheterotrophic metabolic pathways through an empirical parallel metabolic growth constant was proposed. It aimed the modelling of microbial selection dynamics in competition with aerobic and anaerobic microbial community under different operational scenarios. A sensitivity analysis was carried out to identify the most influential parameters within the model and calibrate them based on experimental data. Process perturbation scenarios were simulated, which showed a good performance of the model.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001094606700001 Publication Date 2023-10-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-8524 ISBN Additional Links UA library record; WoS full record
Impact Factor 11.4 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 11.4; 2023 IF: 5.651
Call Number UA @ admin @ c:irua:200035 Serial 8905
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Author (down) Alloul, A.; Ganigue, R.; Spiller, M.; Meerburg, F.; Cagnetta, C.; Rabaey, K.; Vlaeminck, S.E.
Title Capture-ferment-upgrade : a three-step approach for the valorization of sewage organics as commodities Type A1 Journal article
Year 2018 Publication Environmental science and technology Abbreviated Journal
Volume 52 Issue 12 Pages 6729-6742
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract This critical review outlines a roadmap for the conversion of chemical oxygen demand (COD) contained in sewage to commodities based on three-steps: capture COD as sludge, ferment it to volatile fatty acids (VFA), and upgrade VFA to products. The article analyzes the state-of-the-art of this three step approach and discusses the bottlenecks and challenges. The potential of this approach is illustrated for the European Union's 28 member states (EU-28) through Monte Carlo simulations. High-rate contact stabilization captures the highest amount of COD (66-86 g COD person equivalent(-1) day(-1) in 60% of the iterations). Combined with thermal hydrolysis, this would lead to a VFA-yield of 23-44 g COD person equivalent(-1) day(-1). Upgrading VFA generated by the EU-28 would allow, in 60% of the simulations, for a yearly production of 0.2-2.0 megatonnes of esters, 0.7-1.4 megatonnes of polyhydroxyalkanoates or 0.6-2.2 megatonnes of microbial protein substituting, respectively, 20-273%, 70-140% or 21-72% of their global counterparts (i.e., petrochemical-based esters, bioplastics or fishmeal). From these flows, we conclude that sewage has a strong potential as biorefinery feedstock, although research is needed to enhance capture, fermentation and upgrading efficiencies. These developments need to be supported by economic/environmental analyses and policies that incentivize a more sustainable management of our resources.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000436018900004 Publication Date 2018-05-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-936x; 1520-5851 ISBN 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:151968 Serial 7574
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Author (down) Alloul, A.; Cerruti, M.; Adamczyk, D.; Weissbrodt, D.G.; Vlaeminck, S.E.
Title Operational strategies to selectively produce purple bacteria for microbial protein in raceway reactors Type A1 Journal article
Year 2021 Publication Environmental Science & Technology Abbreviated Journal Environ Sci Technol
Volume 55 Issue 12 Pages 8278-8286
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Purple non-sulfur bacteria (PNSB) show potential for microbial protein production on wastewater as animal feed. They offer good selectivity (i.e., low microbial diversity and high abundance of one species) when grown anaerobically in the light. However, the cost of closed anaerobic photobioreactors is prohibitive for protein production. Although open raceway reactors are cheaper, their feasibility to selectively grow PNSB is thus far unexplored. This study developed operational strategies to boost PNSB abundance in the biomass of a raceway reactor fed with volatile fatty acids. For a flask reactor run at a 2 day sludge retention time (SRT), matching the chemical oxygen demand (COD) loading rate to the removal rate in the light period prevented substrate availability during the dark period and increased the PNSB abundance from 50-67 to 88-94%. A raceway reactor run at a 2 day SRT showed an increased PNSB abundance from 14 to 56% when oxygen supply was reduced (no stirring at night). The best performance was achieved at the highest surface-to-volume ratio (10 m(2) m(-3) increased light availability) showing productivities up to 0.2 g protein L-1 day(-1) and a PNSB abundance of 78%. This study pioneered in PNSB-based microbial protein production in raceway reactors, yielding high selectivity while avoiding the combined availability of oxygen, COD, and darkness.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000663939900051 Publication Date 2021-06-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-936x; 1520-5851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.198 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.198
Call Number UA @ admin @ c:irua:179768 Serial 8334
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Author (down) Alloul, A.; Blansaer, N.; Cabecas Segura, P.; Wattiez, R.; Vlaeminck, S.E.; Leroy, B.
Title Dehazing redox homeostasis to foster purple bacteria biotechnology Type A1 Journal article
Year 2023 Publication Trends in biotechnology : regular edition Abbreviated Journal
Volume 41 Issue 1 Pages 106-119
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Purple non-sulfur bacteria (PNSB) show great potential for environmental and industrial biotechnology, producing microbial protein, biohydrogen, polyhydroxyalkanoates (PHAs), pigments, etc. When grown photoheterotrophically, the carbon source is typically more reduced than the PNSB biomass, which leads to a redox imbalance. To mitigate the excess of electrons, PNSB can exhibit several ‘electron sinking’ strategies, such as CO2 fixation, N2 fixation, and H2 and PHA production. The lack of a comprehensive (over)view of these redox strategies is hindering the implementation of PNSB for biotechnology applications. This review aims to present the state of the art of redox homeostasis in phototrophically grown PNSB, presenting known and theoretically expected strategies, and discussing them from stoichiometric, thermodynamic, metabolic, and economic points of view.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000923198400001 Publication Date 2022-07-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1879-3096;0167-7799 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 17.3 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 17.3; 2023 IF: 11.126
Call Number UA @ admin @ c:irua:192944 Serial 7294
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Author (down) Alloul, A.
Title Purple bacteria as microbial protein source : technology development, community control, economic optimization and biomass valorization Type Doctoral thesis
Year 2019 Publication Abbreviated Journal
Volume Issue Pages 212 p.
Keywords Doctoral thesis; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract ​Food production is a cornerstone in contemporary industrial societies. Its production requires land, water and enormous amounts of fertilizers. These precious fertilizers enter the linear food chain and suffer from a cascade of inefficiencies, resulting in detrimental effects to the environment. A radical transforming of the current food production chain is, therefore, essential to guarantee a sustainable future for humanity. ​This thesis has studied the production of microbial protein (i.e. single-cell protein), which is the use of microorganisms such as yeast, fungi, algae and bacteria as protein ingredient for animal feed. The type of microorganisms targeted in this thesis were purple non-sulfur bacteria (PNSB). These bacteria are an extremely heterogenic group that contain photosynthetic pigments and are able to perform anoxygenic photosynthesis. The core focus of the thesis was technology development for the production of PNSB as a source of microbial protein on wastewater and fresh fertilizers. In the final stage of this research, it was the objective to explore the potential of PNSB as a nutritious feed ingredient for shrimp. ​Overall, this work has provided the building blocks to transform the conventional food production chain. The findings show that PNSB production and biomass valorization is within reach. Further pilot implementation and cost reduction will facilitate the introduction of PNSB production in future’s wastewater treatment plants and the valorization of the biomass as nutritious animal feed ingredient.​
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-90-5728-636-0 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:164820 Serial 8430
Permanent link to this record
 

 
Author (down) Allegretta, I.; Legrand, S.; Alfeld, M.; Gattullo, C.E.; Porfido, C.; Spagnuolo, M.; Janssens, K.; Terzano, R.
Title SEM-EDX hyperspectral data analysis for the study of soil aggregates Type A1 Journal article
Year 2022 Publication Geoderma: an international journal of soil science Abbreviated Journal Geoderma
Volume 406 Issue Pages
Keywords A1 Journal article; Antwerp X-ray Imaging and Spectroscopy (AXIS)
Abstract Scanning electron microscopy coupled with microanalysis (SEM-EDX) is an important analytical tool for the morphological and chemical characterization of different types of materials. In many applications, SEM-EDX elemental maps are usually used and processed as images, thus flattening and reducing the spectroscopic information contained in EDX hyperspectral data cubes. The exploitation of the full hyperspectral dataset could be indeed very useful for the study of complex matrices like soil. In order to maximize the information attainable by SEM-EDX data cubes analysis, the software package “Datamuncher Gamma” was implemented and applied to study soil aggregates. By using this approach, different phases (silicates, aluminosilicates, Ca-carbonates, Ca-phosphates, organic matter, iron oxides) inside soil aggregates were successfully identified and segmented. The advantages of this method over the common ROI imaging approach are presented. Finally, this method was used to compare different aggregates in a Cr-polluted soil and understand their possible pedological history. The present method can be used for the analysis of every type of SEM-EDX data cubes, allowing its application to different types of samples and fields of study.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000708893700026 Publication Date 2021-10-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0016-7061 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.1 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.1
Call Number UA @ admin @ c:irua:182493 Serial 7207
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Author (down) Alihosseini, M.; Ghasemi, S.; Ahmadkhani, S.; Alidoosti, M.; Esfahani, D.N.; Peeters, F.M.; Neek-Amal, M.
Title Electronic properties of oxidized graphene : effects of strain and an electric field on flat bands and the energy gap Type A1 Journal article
Year 2021 Publication The journal of physical chemistry letters Abbreviated Journal J Phys Chem Lett
Volume Issue Pages
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract A multiscale modeling and simulation approach, including first-principles calculations, ab initio molecular dynamics simulations, and a tight binding approach, is employed to study band flattening of the electronic band structure of oxidized monolayer graphene. The width offlat bands can be tuned by strain, the external electric field, and the density of functional groups and their distribution. A transition to a conducting state is found for monolayer graphene with impurities when it is subjected to an electric field of similar to 1.0 V/angstrom. Several parallel impurity-induced flat bands appear in the low-energy spectrum of monolayer graphene when the number of epoxy groups is changed. The width of the flat band decreases with an increase in tensile strain but is independent of the electric field strength. Here an alternative and easy route for obtaining band flattening in thermodynamically stable functionalized monolayer graphene is introduced. Our work discloses a new avenue for research on band flattening in monolayer graphene.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000737988100001 Publication Date 2021-12-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1948-7185 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.353 Times cited 7 Open Access Not_Open_Access
Notes Approved Most recent IF: 9.353
Call Number UA @ admin @ c:irua:184725 Serial 6987
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Author (down) Ali, S.; Myasnichenko, V.S.; Neyts, E.C.
Title Size-dependent strain and surface energies of gold nanoclusters Type A1 Journal article
Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 18 Issue 18 Pages 792-800
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Gold nanocluster properties exhibit unique size-dependence. In this contribution, we employ reactive molecular dynamics simulations to calculate the size- and temperature-dependent surface energies, strain energies and atomic displacements for icosahedral, cuboctahedral, truncated octahedral and decahedral Au-nanoclusters. The calculations demonstrate that the surface energy decreases with increasing cluster size at 0 K but increases with size at higher temperatures. The calculated melting curves as a function of cluster size demonstrate the Gibbs-Thomson effect. Atomic displacements and strain are found to strongly depend on the cluster size and both are found to increase with increasing cluster size. These results are of importance for understanding the size-and temperature-dependent surface processes on gold nanoclusters.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000369480600017 Publication Date 2015-11-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 37 Open Access
Notes Approved Most recent IF: 4.123
Call Number UA @ lucian @ c:irua:131626 Serial 4243
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Author (down) Alföldy, B.; Lööv, J.B.; Lagler, F.; Bencs, L.; Horemans, B.; Van Grieken, R.; et al.
Title Measurements of air pollution emission factors for marine transportation in SECA Type A1 Journal article
Year 2013 Publication Atmospheric measurement techniques Abbreviated Journal
Volume 6 Issue 7 Pages 1777-1791
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg−1 fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg−1 fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 × 1015 (kg fuel)−1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000322546800014 Publication Date 2013-07-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1867-1381; 1867-8548 ISBN 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:109265 Serial 8211
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Author (down) Alfeld, M.W.
Title Development of scanning macr-XRF for the investigation of historical paintings Type Doctoral thesis
Year 2013 Publication Abbreviated Journal
Volume Issue Pages 264 p.
Keywords Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
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:111339 Serial 7803
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Author (down) Alfeld, M.; Wahabzada, M.; Bauckhage, C.; Kersting, K.; van der Snickt, G.; Noble, P.; Janssens, K.; Wellenreuther, G.; Falkenberg, G.
Title Simplex Volume Maximization (SiVM): a matrix factorization algorithm with non-negative constrains and low computing demands for the interpretation of full spectral X-ray fluorescence imaging data Type A1 Journal article
Year 2017 Publication Microchemical journal Abbreviated Journal Microchem J
Volume 132 Issue Pages 179-184
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Technological progress allows for an ever-faster acquisition of hyperspectral data, challenging the users to keep up with interpreting the recorded data. Matrix factorization, the representation of data sets by bases (or loads) and coefficient (or score) images is long used to support the interpretation of complex data sets. We propose in this publication Simplex Volume Maximization (SiVM) for the analysis of X-ray fluorescence (XRF) imaging data sets. SiVM selects archetypical data points that represents the data set and thus provides easily understandable bases, preserves the non-negative character of XRF data sets and has low demands concerning computing resources. We apply SiVM on an XRF data set of Hans Memling's Portrait of a man from the Lespinette family from the collection of the Mauritshuis (The Hague, NL) and discuss capabilities and shortcomings of SiVM. (C) 2017 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000399845700026 Publication Date 2017-02-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-265x; 0026-265x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.034 Times cited 8 Open Access
Notes ; The German Federal Ministry of Education and Research (BMBF) is acknowledged for the financial support (Verbundprojekt 05K2012 POISSON: Fortschrittliche Faktorenanalyse ffir Poisson-verteilte Daten). ; Approved Most recent IF: 3.034
Call Number UA @ admin @ c:irua:152647 Serial 5830
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Author (down) Alfeld, M.; Vekemans, B.; Janssens, K.; Falkenberg, G.; Broekaert, J.A.C.; Gao, N.; Gibson, D.
Title Depth profiling of multilayered systems by means of confocal μ-XRF in the laboratory an at HASYLAB BL L: a comparison Type H3 Book chapter
Year 2007 Publication Abbreviated Journal
Volume Issue Pages
Keywords H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:64598 Serial 5572
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Author (down) Alfeld, M.; van der Snickt, G.; Vanmeert, F.; Janssens, K.; Dik, J.; Appel, K.; van der Loeff, L.; Chavannes, M.; Meedendorp, T.; Hendriks, E.
Title Scanning XRF investigation of a Flower Still Life and its underlying composition from the collection of the Kröller-Muller Museum Type A1 Journal article
Year 2013 Publication Applied physics A : materials science & processing Abbreviated Journal Appl Phys A-Mater
Volume 111 Issue 1 Pages 165-175
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000316075700020 Publication Date 2013-01-29
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 35 Open Access
Notes ; This research was supported by the SSD program of BELSPO, Brussels (project S2-ART). Results are also presented here from Gemeenschappelijke Onderzoeksactie (GOA) 'XANES meets ELNES' (Research Fund, University of Antwerp, Belgium) and from Fonds voor Wetenschappelijk Onderzoek (FWO) (Brussels, Belgium) project Nos. G.0704.08 and G.01769.09. The research leading to these results was funded by the European Community's Seventh Framework Program (FP7/2007-2013) under grant agreement No. 226716 and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) under the VIDI project “Looking Over the Painter's Shoulder” (grant No. 700.10.426). M. Alfeld is the recipient of a Ph.D. fellowship of the Research Foundation-Flanders (FWO). ; Approved Most recent IF: 1.455; 2013 IF: 1.694
Call Number UA @ admin @ c:irua:108264 Serial 5826
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Author (down) Alfeld, M.; Siddons, D.P.; Janssens, K.; Dik, J.; Woll, A.; Kirkham, R.; van de Wetering, E.
Title Visualizing the 17th century underpainting in Portrait of an Old Man by Rembrandt van Rijn using synchrotron-based scanning macro-XRF Type A1 Journal article
Year 2013 Publication Applied physics A : materials science & processing Abbreviated Journal Appl Phys A-Mater
Volume 111 Issue 1 Pages 157-164
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In 17th century Old Master Paintings, the underpainting generally refers to the first sketch of a composition. The underpainting is applied to a prepared ground using a monochrome, brown oil paint to roughly indicate light, shade and contours. So far, methods to visualize the underpainting-other than in localized cross-sections-have been very limited. Neither infrared reflectography nor neutron induced autoradiography have proven to be practical, adequate visualization tools. Thus, although of fundamental interest in the understanding of a painting's genesis, the underpainting has virtually escaped all imaging efforts. In this contribution we will show that 17th century underpainting may consist of a highly heterogeneous mixture of pigments, including copper pigments. We suggest that this brown pigment mixture is actually the recycled left-over of a palette scraping. With copper as the heaviest exclusive elemental component, we will hence show in a case study on a Portrait of an Old Man attributed to Rembrandt van Rijn how scanning macro-XRF can be used to efficiently visualize the underpainting below the surface painting and how this information can contribute to the discussion of the painting's authenticity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000316075700019 Publication Date 2012-12-14
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 26 Open Access
Notes ; This research was supported by the SSD programme of BELSPO, Brussels (project S2-ART). The text also presents results of GOA 'XANES meets ELNES' (Research Fund, University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects nos. G.0704.08 and G.01769.09. Further, the research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 226716. M. Alfeld receives a Ph.D. fellowship of the Research Foundation-Flanders (FWO). Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886. We acknowledge the assistance of C. Ryan, CSIRO Australia, in the preparation of the elemental maps using GeoPIXE and Rene Gerritsen (http://www.renegerritsen.nl) in providing photographs, XRR and IRR of the painting. We thank Sullivan Entertainment for documenting part of this project in their TV documentary 'Out of the shadows'. ; Approved Most recent IF: 1.455; 2013 IF: 1.694
Call Number UA @ admin @ c:irua:108263 Serial 5908
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Author (down) Alfeld, M.; Pedroso, J.V.; van Hommes, M.E.; van der Snickt, G.; Tauber, G.; Blaas, J.; Haschke, M.; Erler, K.; Dik, J.; Janssens, K.
Title A mobile instrument for in situ scanning macro-XRF investigation of historical paintings Type A1 Journal article
Year 2013 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 28 Issue 5 Pages 760-767
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Scanning macro-X-ray fluorescence analysis (MA-XRF) is rapidly being established as a technique for the investigation of historical paintings. The elemental distribution images acquired by this method allow for the visualization of hidden paint layers and thus provide insight into the artist's creative process and the painting's conservation history. Due to the lack of a dedicated, commercially available instrument the application of the technique was limited to a few groups that constructed their own instruments. We present the first commercially available XRF scanner for paintings, consisting of an X-ray tube mounted with a Silicon-Drift (SD) detector on a motorized stage to be moved in front of a painting. The scanner is capable of imaging the distribution of the main constituents of surface and sub-surface paint layers in an area of 80 by 60 square centimeters with dwell times below 10 ms and a lateral resolution below 100 mu m. The scanner features for a broad range of elements between Ti (Z = 22) and Mo (Z = 42) a count rate of more than 1000 counts per second (cps)?mass percent and detection limits of 100 ppm for measurements of 1 s duration. Next to a presentation of spectrometric figures of merit, the value of the technique is illustrated through a case study of a painting by Rembrandt's student Govert Flinck (1615-1660).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000317674200019 Publication Date 2013-03-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 106 Open Access
Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents the 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. M. Alfeld receives a Ph. D. fellowship of the Research Foundation-Flanders (FWO). We thank J. Langerock for allowing us to examine the portable altar triptych shown in Fig. 5. ; Approved Most recent IF: 3.379; 2013 IF: 3.396
Call Number UA @ admin @ c:irua:108517 Serial 5453
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Author (down) Alfeld, M.; Laurenze-Landsberg, C.; Denker, A.; Janssens, K.; Noble, P.
Title Neutron activation autoradiography and scanning macro-XRF of Rembrandt van Rijn's Susanna and the Elders (Gemaldegalerie Berlin) : a comparison of two methods for imaging of historical paintings with elemental contrast Type A1 Journal article
Year 2015 Publication Applied physics A : materials science & processing Abbreviated Journal Appl Phys A-Mater
Volume 119 Issue 3 Pages 795-805
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Imaging methods with elemental contrast are of great value for the investigation of historical paintings, as they allow for study of sub-surface layers that provide insight into a painting's creation process. Two of the most important methods are neutron activation autoradiography (NAAR) and scanning macro-XRF (MA-XRF). Given the differences between these methods in the fundamental physical phenomena exploited, a theoretical comparison of their capabilities is difficult and until now a critical comparison of their use on the same painting is missing. In this paper, we present a study of Rembrandt van Rijn's painting Susanna and the Elders from the Gemaldegalerie in Berlin employing both techniques. The painting features a considerable number of overpainted features and a wide range of pigments with different elemental tracers, including earth pigments (Mn/Fe), Azurite (Cu), lead white (Pb), vermilion (Hg) and smalt (Co, As). MA-XRF can detect all elements above Si (Z = 14), suffers from few spectral overlaps and can be performed in a few tens of hours in situ, i.e. in a museum. NAAR requires the stay of the painting at a research facility for several weeks, and inter-element interferences can be difficult to resolve. Also, only a limited number of elements contribute to the acquired autoradiographs, most notably Mn, Cu, As, Co, Hg and P. However, NAAR provides a higher lateral resolution and is less hindered by absorption in covering layers, which makes it the only method capable of visualizing P in lower paint layers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000354189200001 Publication Date 2015-04-13
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 11 Open Access
Notes ; This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents the 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. M. Alfeld received from 2009 to 2013 a PhD fellowship of the Research Foundation-Flanders (FWO). ; Approved Most recent IF: 1.455; 2015 IF: 1.704
Call Number UA @ admin @ c:irua:126034 Serial 5745
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Author (down) Alfeld, M.; Janssens, K.; Sasov, A.; Liu, X.; Kostenko, A.; Rickers-Appel, K.; Falkenberg, G.
Title The use of full-field XRF for simultaneous elemental mapping Type P1 Proceeding
Year 2010 Publication Abbreviated Journal
Volume Issue Pages 111-118
Keywords P1 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The characteristics of a Full-Field X-ray Fluorescence (FF-XRF) set-up for element-specific imaging, installed at the HASYLAB synchrotron radiation source, were determined. A lateral resolution of 10 μm and limits of detection in the percentage range were found. Further potential developments in CCDs available for FF-XRF are discussed and the use of polycapillary lenses as image transfer optics is illustrated in some explorative experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278534600020 Publication Date 2010-04-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-0-7354-0764-0 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 8 Open Access
Notes ; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16) and by GOA XANES meets EELS (Research Fund University of Antwerp, Belgium). M. Alfeld is supported by the Research Foundation – Flanders (FWO). The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/ 2007-2013) under grant agreement no 226716. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:82179 Serial 5891
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Author (down) Alfeld, M.; Janssens, K.; Dik, J.; de Nolf, W.; van der Snickt, G.
Title Optimization of mobile scanning macro-XRF systems for the in situ investigation of historical paintings Type A1 Journal article
Year 2011 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 26 Issue 5 Pages 899-909
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Elemental distribution maps are of great interest in the study of historical paintings, as they allow to investigate the pigment use of the artist, to image changes made in the painting during or after its creation and in some cases to reveal discarded paintings that were later over painted. Yet a method that allows to record such maps of a broad range of elements in a fast, non-destructive and in situ manner is not yet commonly available; a dedicated mobile scanning XRF instrument might fill this gap. In this paper we present three self-built scanning macro-XRF instruments, each based on the experience gained with its precursor. These instruments are compared in terms of sensitivity and limits of detection, which includes a discussion of the use of polycapillary optics and pinhole collimators as beam defining devices. Furthermore, the imaging capabilities of the instruments are demonstrated in three exemplary cases: (parts of) historical paintings from the 15th to the 19th century are examined. These cases illustrate the value of element specific distribution maps in the study of historical paintings and allow in the case of Vincent van Gogh's Patch of Grass a direct comparison between in situ and synchrotron based scanning macro-XRF.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000289731900004 Publication Date 2011-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 107 Open Access
Notes ; The investigation of the “Triptych of the Seven Sacraments'' was done in collaboration with Griet Steyaert, independent restorer, and Lizet Klaassen, Royal Museum of Fine Arts (Antwerp, Belgium). The investigation of ”Patch of Grass'' was realized in collaboration with Luuk van der Loeff, Kroller-Muller-Museum (Otterlo, The Netherlands). M. Alfeld is a PhD fellowship of the Research Foundation-Flanders (FWO). This research was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16) NACHO. The text also presents results of GOA "XANES meets ELNES'' (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0103.04, G.0689.06 and G.0704.08. Further, the work presented was sponsored by the Innovational Research Incentives Scheme of the Netherlands Organization for Scientific Research, NWO (proj. no. 016.118.303). ; Approved Most recent IF: 3.379; 2011 IF: 3.220
Call Number UA @ admin @ c:irua:89919 Serial 5758
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Author (down) Alfeld, M.; Janssens, K.
Title Strategies for processing mega-pixel X-ray fluorescence hyperspectral data: a case study on a version of Caravaggio's painting Supper at Emmaus Type A1 Journal article
Year 2015 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 30 Issue 3 Pages 777-789
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Technical progress in the fields of X-ray sources, optics and detectors is constantly enhancing the pace of data acquisition in XRF imaging. This enlarges the size of the hyperspectral datasets and the number of their sub-parts. This paper describes the challenges in processing large XRF datasets featuring several million pixels/spectra and the strategies developed to overcome them. During the investigation of historical paintings by scanning macro-XRF the main challenges are the correct identification of all spectral features in a dataset and its timely processing. For the identification of spectral features different approaches are discussed, i.e. the use of sum spectra, maximum pixel spectra and of chi(2)(r) maps. For the time-efficient, artefact-free evaluation of XRF imaging data, different software packages are evaluated and intercompared (AXIL, PyMCA, GeoPIXE and the in-house written datamuncher). The process of data evaluation is illustrated on a large dataset (3.4 MPixels) acquired during the investigation of a version of Caravaggio's Supper at Emmaus (143 x 199.5 cm(2)). This 17th century painting is currently the largest object entirely scanned with macroscopic XRF.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000350650800026 Publication Date 2015-02-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 67 Open Access
Notes ; The authors would like to thank W. de Nolf, A. Rothkirch, C. Ryan, A. Sole, B. Vekemans, P. van Espen and L. Vincze for their fruitful discussions over the years. Furthermore, the authors thank D. Swetzoff for his support. M. Alfeld was from 2009 to 2013 the recipient of a Ph.D. fellowship of the Research Foundation-Flanders (FWO, Brussels). ; Approved Most recent IF: 3.379; 2015 IF: 3.466
Call Number UA @ admin @ c:irua:125477 Serial 5848
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Author (down) Alfeld, M.; de Nolf, W.; Cagno, S.; Janssens, K.; et al.
Title Revealing hidden paint layers in oil paintings by means of scanning macro-XRF : a mock-up study based on Rembrandt's “An old man in military costume” Type A1 Journal article
Year 2013 Publication Journal of analytical atomic spectrometry Abbreviated Journal J Anal Atom Spectrom
Volume 28 Issue 1 Pages 40-51
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Over the past several decades the oeuvre of Rembrandt has been the subject of extensive art historical and scientific investigations. One of the most striking features to emerge is his frequent re-use of canvases and panels. The painting An Old Man in Military Costume (78.PB.246), in the collection of the J. Paul Getty Museum, is an example of such a re-used panel. Conventional imaging techniques revealed the presence of a second portrait under the surface portrait, but the details of this hidden portrait have not yet been revealed. Vermilion (HgS) has been identified to have been used nearly exclusively in the flesh tones of the lower painting, suggesting that element-specific XRF imaging might successfully image the hidden portrait. To test this hypothesis, a full-scale mock-up of the painting was created, including a “free impression” of the hidden portrait, reproducing as closely as possible the pigments and paint stratigraphy of the original painting. XRF imaging of the mock-up painting was conducted using three different XRF imaging systems: a mobile X-ray tube based system and two synchrotron-based setups (one equipped with multiple SDDs and one equipped with a Maia detector). The sensitivity, limits of detection and imaging capabilities of each system under the chosen experimental conditions are evaluated and compared. The results indicate that an investigation of the original painting by this method would have an excellent chance of success.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000314903400003 Publication Date 2012-11-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0267-9477 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.379 Times cited 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. Further, the research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 226716. M. Alfeld receives a Ph.D. fellowship of the Research Foundation – Flanders (FWO). The authors gratefully acknowledge Yvonne Szafran and the staff of the Paintings Conservation Department of the J. Paul Getty Museum for making available their infrared reflectography (IRR) and X-radiographic images of the painting, and also the neutron activation analysis (NAA) images acquired in 1996 at NIST by Dr Henry Prask in collaboration with Mark Leonard, former head of the J. Paul Getty Museum Paintings Conservation Department. We are also grateful to Peter Reischig, a graduate intern at the Getty Conservation Institute and a Ph.D. candidate at Delft University of Technology for his assistance. ; Approved Most recent IF: 3.379; 2013 IF: 3.396
Call Number UA @ admin @ c:irua:107704 Serial 5818
Permanent link to this record
 

 
Author (down) Alfeld, M.; Broekaert, J.A.C.
Title Mobile depth profiling and sub-surface imaging techniques for historical paintings : a review Type A1 Journal article
Year 2013 Publication Spectrochimica acta: part B : atomic spectroscopy Abbreviated Journal
Volume 88 Issue Pages 211-230
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. (C) 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000325838900028 Publication Date 2013-07-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0584-8547; 1873-3565 ISBN 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:112232 Serial 8256
Permanent link to this record
 

 
Author (down) Alexiades, V.; Autrique, D.
Title Enthalpy model for heating, melting, and vaporization in laser ablation Type A1 Journal article
Year 2010 Publication Electronic journal of differential equations Abbreviated Journal
Volume Issue Pages 1-13
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Laser ablation is used in a growing number of applications in various areas including medicine, archaeology, chemistry, environmental and materials sciences. In this work the heat transfer and phase change phenomena during nanosecond laser ablation of a copper (Cu) target in a helium (He) background gas at atmospheric pressure are presented. An enthalpy model is outlined, which accounts for heating, melting, and vaporization of the target. As far as we know, this is the first model that connects the thermodynamics and underlying kinetics of this challenging phase change problem in a selfconsistent way.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000455668500001 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1072-6691 ISBN 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:190550 Serial 7925
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