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“LAMMA and electron-microprobe analysis of atmospheric aerosols”. Bruynseels F, Storms H, Van Grieken R, Journal de physique 45, 785 (1984). http://doi.org/10.1051/JPHYSCOL:19842180
Abstract: A laser microprobe mass analyser and a highly automated electron probe X-ray microanalysis unit have been used to study the elemental composition, inorganic speciation and morphology of atmospheric aerosols collected at various remote to polluted and marine to continental locations.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1051/JPHYSCOL:19842180
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“Synergistic exposure of return-sludge to anaerobic starvation, sulfide and free ammonia to suppress nitrite oxidizing bacteria”. Seuntjens D, Van Tendeloo M, Chatzigiannidou I, Carvajal-Arroyo JM, Vandendriessche S, Vlaeminck SE, Boon N, Environmental science and technology 52, 8725 (2018). http://doi.org/10.1021/ACS.EST.7B06591
Abstract: A key step toward energy-positive sewage treatment is the development of mainstream partial nitritation/anammox, a nitrogen removal technology where aerobic ammonium-oxidizing bacteria (AerAOB) are desired, while nitrite-oxidizing bacteria (NOB) are not. To suppress NOB, a novel return-sludge treatment was investigated. Single and combined effects of sulfide (0-600 mg S L-1), anaerobic starvation (0-8 days), and a free ammonia (FA) shock (30 mg FA-N L-1 for 1 h) were tested for immediate effects and long-term recovery. AerAOB and NOB were inhibited immediately and proportionally by sulfide, with AerAOB better coping with the inhibition, while the short FA shock and anaerobic starvation had minor effects. Combinatory effects inhibited AerAOB and NOB more strongly. A combined treatment of sulfide (150 mg S L-1), 2 days of anaerobic starvation, and FA shock (30 mg FA-N L-1) inhibited AerAOB 14% more strongly compared to sulfide addition alone, while the AerAOB/NOB activity ratio remained constant. Despite no positive change being observed in the immediate-stress response, AerAOB recovered much faster than NOB, with a nitrite accumulation ratio (effluent nitrite on nitrite + nitrate) peak of 50% after 12 days. Studying long-term recovery is therefore crucial for design of an optimal NOB-suppression treatment, while applying combined stressors regularly may lead toward practical implementation.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1021/ACS.EST.7B06591
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“Insights into the composition of ancient Egyptian red and black inks on papyri achieved by synchrotron-based microanalyses”. Christiansen T, Cotte M, de Nolf W, Mouro E, Reyes-Herrera J, De Meyer S, Vanmeert F, Salvado N, Gonzalez V, Lindelof PE, Mortensen K, Ryholt K, Janssens K, Larsen S, Proceedings Of The National Academy Of Sciences Of The United States Of America 117, 27825 (2020). http://doi.org/10.1073/PNAS.2004534117
Abstract: A hitherto unknown composition is highlighted in the red and black inks preserved on ancient Egyptian papyri from the Roman period (circa 100 to 200 CE). Synchrotron-based macro-X-ray fluo-rescence (XRF) mapping brings to light the presence of iron (Fe) and lead (Pb) compounds in the majority of the red inks inscribed on 12 papyrus fragments from the Tebtunis temple library. The iron-based compounds in the inks can be assigned to ocher, notably due to the colocalization of Fe with aluminum, and the detection of hematite (Fe2O3) by micro-X-ray diffraction. Using the same techniques together with micro-Fourier transform infrared spectroscopy, Pb is shown to be associated with fatty acid phosphate, sulfate, chloride, and carboxylate ions. Moreover, microXRF maps reveal a peculiar distribution and colocalization of Pb, phosphorus (P), and sulfur (S), which are present at the micrometric scale resembling diffused “coffee rings” surrounding the ocher particles imbedded in the red letters, and at the submicrometric scale concentrated in the papyrus cell walls. A similar Pb, P, and S composition was found in three black inks, suggesting that the same lead components were employed in the manufacture of carbon-based inks. Bearing in mind that pigments such as red lead (Pb3O4) and lead white (hydrocerussite [Pb-3(CO3)(2)(OH)(2)] and/or cerussite [PbCO3]) were not detected, the results presented here suggest that the lead compound in the ink was used as a drier rather than as a pigment. Accordingly, the study calls for a reassessment of the composition of lead-based components in ancient Mediterranean pigments.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 11.1
DOI: 10.1073/PNAS.2004534117
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“NanoMIPs-based electrochemical sensors for selective detection of amphetamine”. Truta F, Cruz AG, Tertis M, Zaleski C, Adamu G, Allcock NS, Suciu M, Stefan M-G, Kiss B, Piletska E, De Wael K, Piletsky SA, Cristea C, Microchemical journal 191, 108821 (2023). http://doi.org/10.1016/J.MICROC.2023.108821
Abstract: A highly sensitive and portable electrochemical sensor based on molecularly imprinted nanoparticles (nanoMIPs) was developed. NanoMIPs were computationally designed for specific recognition of amphetamine, and then synthetized using solid phase synthesis. NanoMIPs were immobilized onto screen-printed carbon electrodes using a composite film comprising chitosan, nanoMIPs, and graphene oxide.Ferrocenylmethyl methacrylate was incorporated in nanoMIPs allowing electrochemical detection. The signal recorded for the electrochemical oxidation of ferrocene has proven to be dependent on the presence of amphetamine interacting with nanMIPs. The sensor was tested successfully with street samples, with high sensitivity and satisfactory recoveries (from 100.9% to 107.6%). These results were validated with UPL-MS/MS. The present technology is suitable for forensic applications in selective determination of amphetamine in street samples.
Keywords: A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Impact Factor: 4.8
DOI: 10.1016/J.MICROC.2023.108821
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“A general Monte-Carlo simulation of energy-dispersive X-ray fluorescence spectrometers : 1 : unpolarized radiation, homogenious samples”. Vincze L, Janssens K, Adams F, Spectrochimica acta: part B : atomic spectroscopy 48, 553 (1993). http://doi.org/10.1016/0584-8547(93)80060-8
Abstract: A general Monte Carlo program for the simulation of X-ray fluorescence (XRF) spectrometers is presented. The global layout of the program is discussed and the way in which variance reduction techniques have been employed to improve the efficiency of the code is described. For the case of polychromatic excitation in a direct excitation energy-dispersive (ED) XRF instrument, experimentally collected ED-XRF spectra are compared with simulated spectral distributions. Applications of the software in the field of quantitative analysis and thickness estimation of samples of intermediate thickness illustrate the potential of the method.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0584-8547(93)80060-8
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“Performance optimization of the nano-sized pick-up loop of a dc-SQUID”. Hasnat A, Physica C-Superconductivity And Its Applications 583, 1353852 (2021). http://doi.org/10.1016/J.PHYSC.2021.1353852
Abstract: A flux transformer, consisting of a superconducting primary loop (pick-up loop) in series with a superconducting secondary loop on which measurement is done, is considered to optimize the approach and sensitivity of the Superconducting QUantum Interference Device (SQUID). Performance of such a pick-up loop placed above a magnetic particle is investigated using the numerical Ginzburg-Landau (GL) simulations. By solving 3D GL equations, static properties of the device such as the distribution of Cooper-pair density and the screening current in the secondary coil have been investigated as a function of the dimensions of the primary loop. Dynamic properties, such as current-voltage characteristics and flux-dependent critical current of the device have also been addressed, all leading to conclusion that smaller size pick-up loop is the first requirement for its optimal sensitivity.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
DOI: 10.1016/J.PHYSC.2021.1353852
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“Determination of total selenium content in cereals and bakery products by flow injection hydride generation graphite furnace atomic absorption spectrometry applying in-situ trapping on iridium-treated graphite platforms”. Ajtony Z, Szoboszlai N, Bella Z, Bolla S, Szakál P, Bencs L, Microchimica acta 150, 1 (2005). http://doi.org/10.1007/S00604-005-0330-Y
Abstract: A flow injection hydride generation graphite furnace atomic absorption spectrometric (FI-HG-GFAAS) method was applied to the determination of Se in Se-doped and undoped cereals and bakery products. For the purpose of doping, the soils used for the cultivation of the cereals were dosed with Se- doped foliar fertilizers. The samples were dissolved in a mixture of HNO(3) and H(2)O(2) solutions using micro-waveassisted digestion. The decomposition of H(2)Se generated from the sample solutions and the trapping of elemental Se were performed at a temperature of 300 degrees C on an Ir-pretreated integrated graphite platform of a transversally heated graphite atomizer(THGA). For release of the trapped Se within a fairly short atomization time (5s), an atomization temperature of 2200 degrees C was observed to be optimal. The overall efficiency of hydride generation, transport and trapping was similar to 86%. The upper limit of the linear dynamic range of calibration was 10 mu gL(-1), which corresponds to 0.5 mu g g(-1) for solid samples. Recovery of the samples spiked with Se(VI) solutions was found to be 93 +/- 6% on average. The relative standard deviation of the determinations was less than 8%. The limit of detection was found to be 0.06 mu gL(-1), corresponding to 3 ng g(-1) for solid samples. The accuracy of the method was verified with the use of IAEA-155 ( whey powder) certified reference material. End-capped THGA tubes resulted in an extension of the linear calibration range compared to that of standard THGAs. The Se content in bakery products made of undoped cereals ranged from 7.7 to 68 ng g(-1) ( wet weight) in 18 samples, whereas the Se content of the corresponding cereals was found to be below 100 ng g(-1) ( wet weight). The Se level of cereals grown on soils treated with Se- doped fertilizers ranged from 128 to 1046 ng g(-1) ( wet weight), and it depended linearly on the Se concentration of the corresponding foliar fertilizer.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S00604-005-0330-Y
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“Electric field gradient calculations in ZnO samples implanted with 111In(111Cd)”. Abreu Y, Cruz CM, van Espen P, Pérez C, Piñera I, Leyva A, Cabal AE, Solid state communications 152, 399 (2012). http://doi.org/10.1016/J.SSC.2011.12.001
Abstract: A first-principles study of the electric field gradient (EFG) calculated for ideal and In-111(Cd-111) implanted ZnO samples is reported in the present work. The study was made for ZnO ideal hexagonal structures and supercells were introduced in order to consider the possible implantation environments. The calculation was done using the “WIEN2k” code within the density functional theory, the exchange and correlation effects were determined by the GGA approximation. Three possible In-111(Cd-111) implantation configurations were studied, one substitutional incorporation at cation site and two interstitials. The obtained EFG values for the ideal structure and the substitutional site are in good agreement with the experimental reports measured by perturbed angular correlation (PAC) and high precision nuclear magnetic resonance (NMR). Thus, the ascription of substitutional incorporation of In-111(Cd-111) probe atom at the ZnO cation site after annealing was confirmed. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.SSC.2011.12.001
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“Simultaneous determination of silicon and phosphorus in cast iron by 14 MeV neutron activation analysis”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 6, 385 (1970). http://doi.org/10.1007/BF02513966
Abstract: A fast (10 min), non-destructive simultaneous determination of silicon and phosphorus in cast iron and steel by 14 MeV neutron activation was developed. The 1.78 MeV28Al activity (T=2.24 min) induced by the reaction28Si(n, p)28Al is counted on a NaI(Tl) detector. Two measurements are made to correct for the 1.81 MeV56Mn activity (T=2.58 hr) from the iron matrix. However,28Al is also produced via31P(n, α)28Al. By (n, 2n) reaction, phosphorus yields also30P (T=2.6 min), the 0.511 MeV annihilation radiation of which is counted by two opposite NaI(Tl) detectors in coincidence. Again, two successive coincidence measurements are carried out in order to take into account the53Fe activity (β+; T=8.9 min) from54Fe(n, 2n)53Fe. The28Al measurement is appropriately corrected via the computed phosphorus content. An oxygen flux monitor was used to normalize to the same flux. Nuclear interferences have been examined. Special attention has been paid to the presence of copper. The standard deviation for phosphorus being as high as ca. 0.09% P for a single determination, this technique can only be practical as an independent phosphorus analysis for high phosphorus cast irons. The precision on the28Al measurement is 5% relative for 0.2% Si and 2.5% above 1% Si.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02513966
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“The determination of copper in iron and steel by 14-Mev neutron activation analysis”. Van Grieken R, Speecke A, Hoste J, Analytica chimica acta 51, 151 (1970). http://doi.org/10.1016/S0003-2670(01)95703-4
Abstract: A fast (10 min) non-destructive determination of copper in. steel and cast iron by 14-MeV neutron activation analysis is described. The 0.511-MeV annihilation radiation of62Cu (T1/2=9.8 min), induced by the reaction63Cu(n,2n)62Cu, is counted by two opposing NaI(Tl) detectors operating in coincidence. An oxygen flux monitor is used to normalise the irradiations. For high phosphorus contents, two measurements are made and the 9-min activity contribution is calculated. As the iron content of the samples is known, the use of pure iron samples allows correction for53Fe activity from the reaction54Fe(n,2n)53Fe(T1/2= 8.9 min). When the phosphorus and silicon activities are low, the procedure of counting and computing can be greatly simplified. Nuclear interferences of most common alloying and impurity elements were investigated.The precision is 23% for steels containing above 1% Cu, andCa. 10% for 0.1%Cu.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0003-2670(01)95703-4
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“Analysis of indoor gaseous formic and acetic acid, using radial diffusive samplers”. Stranger M, Potgieter-Vermaak S, Sacco P, Quaglio F, Pagani D, Cocheo C, Godoi AFL, Van Grieken R, Environmental monitoring and assessment 149, 411 (2009). http://doi.org/10.1007/S10661-008-0217-6
Abstract: A diffusive sampling method for the determination of gaseous acetic and formic acids, using a radial symmetry diffusive sampler, has been optimised for a 7-day exposure time in this study. Sampling rate determinations were performed on data obtained from a dynamic exposure chamber, simulating the indoor conditions of an empty, closed, room, at room temperature and minimal wind speed. Analysis has been performed by means of ion chromatography. The sampling rates for formic acid concentrations of 128 ìg m−3 and 1248 ìg m−3 were determined to be 91.2 ± 3.9 ml min−1 and 111.6 ± 2.8 ml min−1, respectively. The acetic acid sampling rate was independent of the concentration in the range 160 ìg m−31564 ìg m−3, and amounted to 97.3 ± 3.1 ml min−1. Experimentally determined sampling rates showed deviations of 3% for acetic acid, and 321% for formic acid, in relation to theoretically derived values. The blank values were as low as 1.69 ± 0.07 ìg for formic acid and 1.21 ± 0.14 ìg for acetic acid, and detection limits lower than 0.5 ìg m−3 could be achieved, which is an improvement of 9899% compared to previously validated diffusive sampling methods. This study describes the first step of an extended validation program in which the applicability of these types of samplers for the measurement of organic acids will be validated and optimised for the environmental conditions typical for museum showcases.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/S10661-008-0217-6
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“Probing the electron beam-induced structural evolution of halide perovskite thin films by scanning transmission electron microscopy”. Zhou X-G, Yang C-Q, Sang X, Li W, Wang L, Yin Z-W, Han J-R, Li Y, Ke X, Hu Z-Y, Cheng Y-B, Van Tendeloo G, Journal Of Physical Chemistry C 125, 10786 (2021). http://doi.org/10.1021/ACS.JPCC.1C02156
Abstract: A deep understanding of the fine structure at the atomic scale of halide perovskite materials has been limited by their sensitivity to the electron beam that is widely used for structural characterization. The sensitivity of a gamma-CsPbIBr2 perovskite thin film under electron beam irradiation is revealed by scanning transmission electron microscopy (STEM) through a universal large-range electron dose measurement, which is based on discrete single-electron events in the STEM mode. Our research indicates that the gamma-CsPbIBr2 thin film undergoes structural changes with increasing electron overall dose (e(-).A(-2)) rather than dose rate (e(-).A(-2).s(-1)), which suggests that overall dose is the key operative parameter. The electron beam-induced structural evolution of gamma-CsPbIBr2 is monitored by fine control of the electron beam dose, together with the analysis of high-resolution (S)TEM, diffraction, and energy-dispersive X-ray spectroscopy. Our results show that the gamma-CsPbIBr2 phase first forms an intermediate phase [e.g., CsPb(1-x)(IBr)((3-y))] with a superstructure of ordered vacancies in the pristine unit cell, while a fraction of Pb2+ is reduced to Pb-0. As the electron dose increases, Pb nanoparticles precipitate, while the remaining framework forms the Cs2IBr phase, accompanied by some amorphization. This work provides guidelines to minimize electron beam irradiation artifacts for atomic-resolution imaging on CsPbIBr2 thin films.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
DOI: 10.1021/ACS.JPCC.1C02156
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“Identifying alternative ferroelectric materials beyond Hf(Zr)O-₂”. Guo J, Clima S, Pourtois G, Van Houdt J, Applied Physics Letters 117, 262903 (2020). http://doi.org/10.1063/5.0028611
Abstract: A database-driven approach combined with ab initio density functional theory (DFT) simulations is used to identify and simulate alternative ferroelectric materials beyond Hf(Zr)O-2. The database-driven screening method identifies a class of wurtzite ferroelectric materials. DFT simulations of wurtzite magnesium chalcogenides, including MgS, MgSe, and MgTe, show their potential to achieve improved ferroelectric (FE) stability, simple atomistic unit cell structure, and large FE polarization. Strain engineering can effectively modulate the FE switching barrier height for facilitating FE switching. The effect of the piezoelectric property on the FE switching barrier heights is also examined.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4
DOI: 10.1063/5.0028611
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“Ab initio calculations and a scratch test study of RF-magnetron sputter deposited hydroxyapatite and silicon-containing hydroxyapatite coatings”. Surmenev RA, Grubova IY, Neyts E, Teresov AD, Koval NN, Epple M, Tyurin AI, Pichugin VF, Chaikina MV, Surmeneva MA, Surfaces and interfaces 21 (2020). http://doi.org/10.1016/J.SURFIN.2020.100727
Abstract: A crucial property for implants is their biocompatibility. To ensure biocompatibility, thin coatings of hydroxyapatite (HA) are deposited on the actual implant. In this study, we investigate the effects of the addition of silicate anions to the structure of hydroxyapatite coatings on their adhesion strength via a scratch test and ab initio calculations. We find that both the grain size and adhesion strength decrease with the increase in the silicon content in the HA coating (SiHA). The increase in the silicon content to 1.2 % in the HA coating leads to a decrease in the average crystallite size from 28 to 21 nm, and in the case of 4.6 %, it leads to the formation of an amorphous or nanocrystalline film. The decreases in the grain and crystallite sizes lead to peeling and destruction of the coating from the titanium substrate at lower loads. Further, our ab initio simulations demonstrate an increased number of molecular bonds at the amorphous SiHA-TiO2 interface. However, the experimental results revealed that the structure and grain size have more pronounced effects on the adhesion strength of the coatings. In conclusion, based on the results of the ab initio simulations and the experimental results, we suggest that the presence of Si in the form of silicate ions in the HA coating has a significant impact on the structure, grain size, and number of molecular bonds at the interface and on the adhesion strength of the SiHA coating to the titanium substrate.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.2
DOI: 10.1016/J.SURFIN.2020.100727
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“Automated evaluation of photographically recorded spark-source mass spectra”. Vanderborght B, Van Grieken R, Analytica chimica acta 103, 223 (1978). http://doi.org/10.1016/S0003-2670(01)84041-1
Abstract: A computer routine was developed for qualitative and quantitative analysis of photographically recorded spark-source mass spectra. Particular attention is given to the case of a graphite matrix. The program starts from the line intensities (expressed as Seidel values) and isotope masses calculated from the densitometer readings by a commercially available routine. From the intensities in the different exposures (typically 15 stages), it computes the parameters for the linear parts of the density curves for each ion. Taking into account mutual interferences of multivalent ions, isotope or C-clusters, oxide, carbide and dicarbide ions, the program automatically identifies and then quantifies the elements present. The precision of the results is around 5%. Reading and complete processing of one photoplate is achieved within 23 h.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0003-2670(01)84041-1
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“Determination of barium, lanthanum, cerium and neodymium in lateritic materials by various energy-dispersive X-ray fluorescence techniques and neutron activation analysis”. Labrecque JJ, Beusen JM, Van Grieken RE, X-ray spectrometry 15, 13 (1986). http://doi.org/10.1002/XRS.1300150105
Abstract: A comparison of four methods for the determination of barium, lanthanum, cerium and neodymium in lateritic materials from Brazil is presented. Three of the methods were based on x-ray fluorescence (XRF) spectroscopy: two by radioisotope excitation (Co-57 and Am-241) and one by secondary target XRF (a molybdenum target with a tungsten anode). The other method was based on neutron activation analysis employing both a Ge(Li) coaxial detector and a high-purity germanium detector. The results from these four methods were similar for lanthanum, cerium and neodymium, but for barium at low concentrations (<500 ppm) the neutron activation and the secondary target XRF methods were not suitable. Data on the precision and accuracy of these methods using a series of standard reference rocks are given. The advantages and limitations of each of these methods with respect to the analysis of lateritic materials are discussed.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.1300150105
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“TMDlib2 and TMDplotter : a platform for 3D hadron structure studies”. Abdulov NA, Bacchetta A, Baranov S, Martinez AB, Bertone V, Bissolotti C, Candelise V, Banos LIE, Bury M, Connor PLS, Favart L, Guzman F, Hautmann F, Hentschinski M, Jung H, Keersmaekers L, Kotikov A, Kusina A, Kutak K, Lelek A, Lidrych J, Lipatov A, Lykasov G, Malyshev M, Mendizabal M, Prestel S, Barzani SS, Sapeta S, Schmitz M, Signori A, Sorrentino G, Monfared ST, van Hameren A, van Kampen AM, Vanden Bemden M, Vladimirov A, Wang Q, Yang H, European Physical Journal C 81, 752 (2021). http://doi.org/10.1140/EPJC/S10052-021-09508-8
Abstract: A common library, TMDlib2, for Transverse-Momentum-Dependent distributions (TMDs) and unintegrated parton distributions (uPDFs) is described, which allows for easy access of commonly used TMDs and uPDFs, providing a three-dimensional (3D) picture of the partonic structure of hadrons. The tool TMDplotter allows for web-based plotting of distributions implemented in TMDlib2, together with collinear pdfs as available in LHAPDF.
Keywords: A1 Journal article; Particle Physics Group; Condensed Matter Theory (CMT)
Impact Factor: 5.331
DOI: 10.1140/EPJC/S10052-021-09508-8
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“Synchrotron-based X-ray fluorescence imaging elucidates uranium toxicokinetics in Daphnia magna”. Byrnes I, Rossbach LM, Brede DA, Grolimund D, Sanchez DF, Nuyts G, Cuba V, Reinoso-Maset E, Salbu B, Janssens K, Oughton D, Scheibener S, Teien H-C, Lind OC, ACS nano 17, 5296 (2023). http://doi.org/10.1021/ACSNANO.2C06111
Abstract: A combination of synchrotron-based elemental anal-ysis and acute toxicity tests was used to investigate the biodistribution and adverse effects in Daphnia magna exposed to uranium nanoparticle (UNP, 3-5 nm) suspensions or to uranium reference (Uref) solutions. Speciation analysis revealed similar size distributions between exposures, and toxicity tests showed com-parable acute effects (UNP LC50: 402 mu g L-1 [336-484], Uref LC50: 268 mu g L-1 [229-315]). However, the uranium body burden was 3 -to 5-fold greater in UNP-exposed daphnids, and analysis of survival as a function of body burden revealed a similar to 5-fold higher specific toxicity from the Uref exposure. High-resolution X-ray fluorescence elemental maps of intact, whole daphnids from sublethal, acute exposures of both treatments revealed high uranium accumulation onto the gills (epipodites) as well as within the hepatic ceca and the intestinal lumen. Uranium uptake into the hemolymph circulatory system was inferred from signals observed in organs such as the heart and the maxillary gland. The substantial uptake in the maxillary gland and the associated nephridium suggests that these organs play a role in uranium removal from the hemolymph and subsequent excretion. Uranium was also observed associated with the embryos and the remnants of the chorion, suggesting uptake in the offspring. The identification of target organs and tissues is of major importance to the understanding of uranium and UNP toxicity and exposure characterization that should ultimately contribute to reducing uncertainties in related environmental impact and risk assessments.
Keywords: A1 Journal article; Engineering sciences. Technology; Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 17.1
DOI: 10.1021/ACSNANO.2C06111
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“Synchrotron XRF analysis identifies cerium accumulation colocalized with pharyngeal deformities in CeO₂, NP-exposed caenorhabditis elegans”. Rossbach LM, Brede DA, Nuyts G, Cagno S, Olsson RMS, Oughton DH, Falkenberg G, Janssens K, Lind OC, Environmental science and technology 56, 5081 (2022). http://doi.org/10.1021/ACS.EST.1C08509
Abstract: A combination of synchrotron radiation-based elementalimaging, in vivo redox status analysis, histology, and toxic responses was usedto investigate the uptake, biodistribution, and adverse effects of Cenanoparticles (CeO2NP; 10 nm; 0.5-34.96 mg Ce L-1) or Ce(NO3)3(2.3-26 mg Ce L-1)inCaenorhabditis elegans. Elemental mapping of theexposed nematodes revealed Ce uptake in the alimentary canal prior todepuration. Retention of CeO2NPs was low compared to that of Ce(NO3)3in depurated individuals. X-rayfluorescence (XRF) mapping showed that Cetranslocation was confined to the pharyngeal valve and foregut. Ce(NO3)3exposure significantly decreased growth, fertility, and reproduction, causedslightly reduced fecundity. XRF mapping and histological analysis revealedsevere tissue deformities colocalized with retained Ce surrounding thepharyngeal valve. Both forms of Ce activated the sod-1 antioxidant defense,particularly in the pharynx, whereas no significant effects on the cellular redox balance were identified. The CeO2NP-induceddeformities did not appear to impair the pharyngeal function or feeding ability as growth effects were restricted to Ce(NO3)3exposure. The results demonstrate the utility of integrated submicron-resolution SR-based XRF elemental mapping of tissue-specificdistribution and adverse effect analysis to obtain robust toxicological evaluations of metal-containing contaminants.
Keywords: A1 Journal article; Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 11.4
DOI: 10.1021/ACS.EST.1C08509
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“An integrated techno-sustainability assessment (TSA) framework for emerging technologies”. Van Schoubroeck S, Thomassen G, Van Passel S, Malina R, Springael J, Lizin S, Venditti RA, Yao Y, Van Dael M, Green Chemistry 23, 1700 (2021). http://doi.org/10.1039/D1GC00036E
Abstract: A better understanding of the drivers of the economic, environmental, and social sustainability of emerging (biobased) technologies and products in early development phases can help decision-makers to identify sustainability hurdles and opportunities. Furthermore, it guides additional research and development efforts and investment decisions, that will, ultimately, lead to more sustainable products and technologies entering a market. To this end, this study developed a novel techno-sustainability assessment (TSA) framework with a demonstration on a biobased chemical application. The integrated TSA compares the potential sustainability performance of different (technology) scenarios and helps to make better-informed decisions by evaluating and trading-off sustainability impacts in one holistic framework. The TSA combines methods for comprehensive indicator selection and integration of technological and country-specific data with environmental, economic, and social data. Multi-criteria decision analysis (MCDA) is used to address data uncertainty and to enable scenario comparison if indicators are expressed in different units. A hierarchical, stochastic outranking approach is followed that compares different weighting schemes and preference structures to check for the robustness of the results. The integrated TSA framework is demonstrated on an application for which the sustainability of a production and harvesting plant of microalgae-based food colorants is assessed. For a set of scenarios that vary with regard to the algae feedstock, production technology, and location, the sustainability performance is quantified and compared, and the underlying reasons for this performance are explored.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 9.125
DOI: 10.1039/D1GC00036E
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“DIY measurement of your personal HRTF at home : low-cost, fast and validated”. Reijniers J, Partoens B, Peremans H, , 1 (2017)
Abstract: <script type='text/javascript'>document.write(unpmarked('The breakthrough of 3D audio has been hampered by the lack of personalized head-related transfer functions (HRTF) required to create realistic 3D audio environments using headphones. In this paper we present a new method for the user to personalize his/her HRTF, similar to the measurement in an anechoic room, yet it is low-cost and can be carried out at home. We compare the resulting HRTFs with those measured in an anechoic room. Subjecting the participants to a virtual localization experiment, we show that they perform significantly better when using their personalized HRTF, compared to a generic HRTF. We believe this method has the potential of opening the way for large scale commercial use of 3D audio through headphones.'));
Keywords: P3 Proceeding; Engineering sciences. Technology; Engineering Management (ENM); Condensed Matter Theory (CMT)
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Van Alphen S (2023) Modelling plasma reactors for sustainable CO2 conversion and N2 fixation. 202 p
Abstract: 200 years ago, humanity started the industrial revolution by discovering fossil fuels, which lead to unprecedented technological advancements. However it has become alarmingly clear that the major environmental concerns associated with fossil fuels require a short-term transition from a carbon-based energy economy to a sustainable one based on green electricity. A key step concerning this transition exists in developing electricity-driven alternatives for chemical processes that rely on fossil fuels as a raw material. A technology that is gaining increasing interest to achieve this, is plasma technology. Using plasmas to induce chemical reactions by selectively heating electrons in a gas has already delivered promising results for gas conversion applications like CO2 conversion and N2 fixation, but plasma reactors still require optimization to be considered industrially competitive to existing fossil fuel-based processes and emerging other electricity-based technologies. In this thesis I develop computational models to describe plasma reactors and identify key mechanisms in three different plasma reactors for three different gas conversion applications, i.e. N2 fixation, combined CO2-CH4 conversion and CO2 splitting. I first developed models to describe a new rotating gliding arc (GA) reactor operating in two arc modes, which, as revealed by my model, are characterized by distinct plasma chemistry pathways. Subsequently, my colleague and I study the quenching effect of an effusion nozzle to this rotating GA reactor, reaching the best results to date for N2 fixation into NOx at atmospheric pressure, i.e., NOx concentrations up to 5.9%, at an energy cost down to 2.1 MJ/mol. Afterwards, I investigate the possible improvement of N2 admixtures in plasma-based CO2 and CH4 conversion, as significant amounts of N2 are often found in industrial CO2 waste streams, and gas separations are financially costly. Through combining my models with the experiment from a fellow PhD student, we reveal that moderate amounts of N2 (i.e. around 20%) increase both the electron density and the gas temperature to yield an overall energy cost reduction of 21%. Finally, I model quenching nozzles for plasma-based CO2 conversion in a microwave reactor, to explain the enhancements in CO2 conversion that were demonstrated in experiments. Through computational modelling I reveal that the nozzle introduces fast gas quenching resulting in the suppression of recombination reactions, which have more impact at low flow rates, where recombination is the most limiting factor in the conversion process.
Keywords: Doctoral thesis; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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“Plasmonic hybrid nanostructures in photocatalysis : structures, mechanisms, and applications”. Ninakanti R, Dingenen F, Borah R, Peeters H, Verbruggen SW, Topics in Current Chemistry 380, 40 (2022). http://doi.org/10.1007/S41061-022-00390-W
Abstract: (Sun)Light is an abundantly available sustainable source of energy that has been used in catalyzing chemical reactions for several decades now. In particular, studies related to the interaction of light with plasmonic nanostructures have been receiving increased attention. These structures display the unique property of localized surface plasmon resonance, which converts light of a specific wavelength range into hot charge carriers, along with strong local electromagnetic fields, and/or heat, which may all enhance the reaction efficiency in their own way. These unique properties of plasmonic nanoparticles can be conveniently tuned by varying the metal type, size, shape, and dielectric environment, thus prompting a research focus on rationally designed plasmonic hybrid nanostructures. In this review, the term “hybrid” implies nanomaterials that consist of multiple plasmonic or non-plasmonic materials, forming complex configurations in the geometry and/or at the atomic level. We discuss the synthetic techniques and evolution of such hybrid plasmonic nanostructures giving rise to a wide variety of material and geometric configurations. Bimetallic alloys, which result in a new set of opto-physical parameters, are compared with core–shell configurations. For the latter, the use of metal, semiconductor, and polymer shells is reviewed. Also, more complex structures such as Janus and antenna reactor composites are discussed. This review further summarizes the studies exploiting plasmonic hybrids to elucidate the plasmonic-photocatalytic mechanism. Finally, we review the implementation of these plasmonic hybrids in different photocatalytic application domains such as H2 generation, CO2 reduction, water purification, air purification, and disinfection.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1007/S41061-022-00390-W
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“Magnetic field oriented tetragonal zirconia with anisotropic toughness”. Zhang L, Vleugels J, Darchuk L, van der Biest O, Journal of the European Ceramic Society 31, 1405 (2011). http://doi.org/10.1016/J.JEURCERAMSOC.2011.02.002
Abstract: (0 0 1)-oriented 3 mol% yttria stabilized tetragonal zirconia (3Y-TZP) has been developed by reactive synthesis of undoped pure monoclinic zirconia and co-precipitated 8 mol% yttria-stabilized zirconia (8Y-ZrO2). The dispersed pure monoclinic ZrO2 powder, having magnetic anisotropy, was first aligned in a strong magnetic field and co-sintered in a randomly distributed cubic 8Y-ZrO2 fine matrix powder. The reactive sintering resulted in a 3Y-TZP ceramic with a (0 0 1) orientation. The (0 0 1)-oriented 3Y-TZP showed a substantial toughness anisotropy, i.e. the toughness along the [0 0 1] direction is 54% higher than that of its perpendicular direction. Moreover, the toughness along the [0 0 1] direction is 49% higher than that of a non-textured isotropic reactively synthesized 3Y-TZP and 110% higher than that of an isotropic co-precipitated powder based 3Y-TZP. The substantially enhanced toughness was interpreted in terms of the tetragonal to monoclinic martensitic phase transformability.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.JEURCERAMSOC.2011.02.002
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“2-D rotational invariant multi sub band Schrödinger-Poisson solver to model nanowire transistors”. Sels D, Sorée B, Groeseneken G, 14th International Workshop on Computational Electronics, 85 (2010)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
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“2D semiconductors at the Leuven pulsed field facility”. Bogaerts R, de Keyser A, van Bockstal L, van der Burgt M, van Esch A, Provoost R, Silverans R, Herlach F, Swinnen B, van de Stadt AFW, Koenraad PM, Wolter JH, Karavolas VC, Peeters FM, van de Graaf W, Borghs G, Physicalia magazine 19, 229 (1997)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“3D reconstruction of a Ni51Ti49 alloy with precipitates by FIB-SEM alice-and-view”. Cao S, Tirry W, Schryvers D, Materia Japan 46, 803 (2007)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
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“65th birthdays of W. Owen Saxton, David J. Smith and Dirk Van Dyck / PICO 2013 From multislice to big bang”. Lichte H, Dunin-Borkowski R, Tillmann K, Van Aert S, Van Tendeloo G Amsterdam (2013).
Keywords: ME3 Book as editor; Electron microscopy for materials research (EMAT)
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“An ab initio study of the C3+ cation using multireference methods”. Taylor PR, Martin JML, François JP, Gijbels R, The journal of chemical physics 95, 6530 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.952
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“Accurate measurements of atomic displacements in La0.9Sr0.1MnO3 thin films grown on a SrTiO3 substrate”. Geuens P, Lebedev OI, van Dyck D, Van Tendeloo G s.l., page 1133 (2000).
Keywords: H3 Book chapter; Electron microscopy for materials research (EMAT); Vision lab
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