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“Oxygen control and stressor treatments for complete and long-term suppression of nitrite-oxidizing bacteria in biofilm-based partial nitritation/anammox”. Van Tendeloo M, Xie Y, Van Beeck W, Zhu W, Lebeer S, Vlaeminck SE, Bioresource Technology 342, 125996 (2021). http://doi.org/10.1016/J.BIORTECH.2021.125996
Abstract: Mainstream nitrogen removal by partial nitritation/anammox (PN/A) can realize energy and cost savings for sewage treatment. Selective suppression of nitrite oxidizing bacteria (NOB) remains a key bottleneck for PN/A implementation. A rotating biological contactor was studied with an overhead cover and controlled air/N2 inflow to regulate oxygen availability at 20 °C. Biofilm exposure to dissolved oxygen concentrations < 0.51 ± 0.04 mg O2 L-1 when submerged in the water and < 1.41 ± 0.31 mg O2 L-1 when emerged in the headspace (estimated), resulted in complete and long-term NOB suppression with a low relative nitrate production ratio of 10 ± 4%. Additionally, weekly biofilm stressor treatments with free ammonia (FA) (29 ± 1 mg NH3-N L-1 for 3 h) could improve the NOB suppression while free nitrous acid treatments had insufficient effect. This study demonstrated the potential of managing NOB suppression in biofilm-based systems by oxygen control and recurrent FA exposure, opening opportunities for resource efficient nitrogen removal.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 5.651
DOI: 10.1016/J.BIORTECH.2021.125996
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“Up close: Center for Electron Microscopy of Materials Science at the University of Antwerp”. Van Tendeloo G, Schryvers D, van Dyck D, van Landuyt J, Amelinckx S, MRS bulletin , 57 (1994)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 5.667
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“Ensemble-Based Molecular Simulation of Chemical Reactions under Vibrational Nonequilibrium”. Bal KM, Bogaerts A, Neyts EC, Journal Of Physical Chemistry Letters 11, 401 (2020). http://doi.org/10.1021/acs.jpclett.9b03356
Abstract: We present an approach to incorporate the effect of vibrational nonequilibrium in molecular dynamics (MD) simulations. A perturbed canonical ensemble, in which selected modes are excited to higher temperature while all others remain equilibrated at low temperature, is simulated by applying a specifically tailored bias potential. Our method can be readily applied to any (classical or quantum mechanical) MD setup at virtually no additional computational cost and allows the study of reactions of vibrationally excited molecules in nonequilibrium environments such as plasmas. In combination with enhanced sampling methods, the vibrational efficacy and mode selectivity of vibrationally stimulated reactions can then be quantified in terms of chemically relevant observables, such as reaction rates and apparent free energy barriers. We first validate our method for the prototypical hydrogen exchange reaction and then show how it can capture the effect of vibrational excitation on a symmetric SN2 reaction and radical addition on CO2.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 5.7
DOI: 10.1021/acs.jpclett.9b03356
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“Formation of Hollow Gold Nanocrystals by Nanosecond Laser Irradiation”. González-Rubio G, Milagres de Oliveira T, Albrecht W, Díaz-Núñez P, Castro-Palacio JC, Prada A, González RI, Scarabelli L, Bañares L, Rivera A, Liz-Marzán LM, Peña-Rodríguez O, Bals S, Guerrero-Martínez A, Journal Of Physical Chemistry Letters 11, 670 (2020). http://doi.org/10.1021/acs.jpclett.9b03574
Abstract: The irradiation of spherical gold nanoparticles (AuNPs) with nanosecond laser pulses induces shape transformations yielding nanocrystals with an inner cavity. The concentration of the stabilizing surfactant, the use of moderate pulse fluences, and the size of the irradiated AuNPs determine the efficiency of the process and the nature of the void. Hollow nanocrystals are obtained when molecules from the surrounding medium (e.g., water and organic matter derived from the surfactant) are trapped during laser pulse irradiation. These experimental observations suggest the existence of a subtle balance between the heating and cooling processes experienced by the nanocrystals, which induce their expansion and subsequent recrystallization keeping exogenous matter inside. The described approach provides valuable insight into the mechanism of interaction of pulsed nanosecond laser with AuNPs, along with interesting prospects for the development of hollow plasmonic nanoparticles with potential applications related to gas and liquid storage at the nanoscale.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.7
Times cited: 15
DOI: 10.1021/acs.jpclett.9b03574
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“Storage, fertilization and cost properties highlight the potential of dried microbial biomass as organic fertilizer”. Spanoghe J, Grunert O, Wambacq E, Sakarika M, Papini G, Alloul A, Spiller M, Derycke V, Stragier L, Verstraete H, Fauconnier K, Verstraete W, Haesaert G, Vlaeminck SE, Microbial biotechnology , 1 (2020). http://doi.org/10.1111/1751-7915.13554
Abstract: The transition to sustainable agriculture and horticulture is a societal challenge of global importance. Fertilization with a minimum impact on the environment can facilitate this. Organic fertilizers can play an important role, given their typical release pattern and production through resource recovery. Microbial fertilizers (MFs) constitute an emerging class of organic fertilizers and consist of dried microbial biomass, for instance produced on effluents from the food and beverage industry. In this study, three groups of organisms were tested as MFs: a high-rate consortium aerobic bacteria (CAB), the microalga Arthrospira platensis (‘Spirulina’) and a purple non-sulfur bacterium (PNSB) Rhodobacter sp. During storage as dry products, the MFs showed light hygroscopic activity, but the mineral and organic fractions remained stable over a storage period of 91 days. For biological tests, a reference organic fertilizer (ROF) was used as positive control, and a commercial organic growing medium (GM) as substrate. The mineralization patterns without and with plants were similar for all MFs and ROF, with more than 70% of the organic nitrogen mineralized in 77 days. In a first fertilization trial with parsley, all MFs showed equal performance compared to ROF, and the plant fresh weight was even higher with CAB fertilization. CAB was subsequently used in a follow-up trial with petunia and resulted in elevated plant height, comparable chlorophyll content and a higher amount of flowers compared to ROF. Finally, a cost estimation for packed GM with supplemented fertilizer indicated that CAB and a blend of CAB/PNSB (85%/15%) were most cost competitive, with an increase of 6% and 7% in cost compared to ROF. In conclusion, as biobased fertilizers, MFs have the potential to contribute to sustainable plant nutrition, performing as good as a commercially available organic fertilizer, and to a circular economy.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 5.7
DOI: 10.1111/1751-7915.13554
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“Insights into water permeation through hBN nanocapillaries by ab initio machine learning molecular dynamics simulations”. Ghorbanfekr H, Behler J, Peeters FM, Journal Of Physical Chemistry Letters 11, 7363 (2020). http://doi.org/10.1021/ACS.JPCLETT.0C01739
Abstract: Water permeation between stacked layers of hBN sheets forming 2D nanochannels is investigated using large-scale ab initio-quality molecular dynamics simulations. A high-dimensional neural network potential trained on density-functional theory calculations is employed. We simulate water in van der Waals nanocapillaries and study the impact of nanometric confinement on the structure and dynamics of water using both equilibrium and nonequilibrium methods. At an interlayer distance of 10.2 A confinement induces a first-order phase transition resulting in a well-defined AA-stacked bilayer of hexagonal ice. In contrast, for h < 9 A, the 2D water monolayer consists of a mixture of different locally ordered patterns of squares, pentagons, and hexagons. We found a significant change in the transport properties of confined water, particularly for monolayer water where the water-solid friction coefficient decreases to half and the diffusion coefficient increases by a factor of 4 as compared to bulk water. Accordingly, the slip-velocity is found to increase under confinement and we found that the overall permeation is dominated by monolayer water adjacent to the hBN membranes at extreme confinements. We conclude that monolayer water in addition to bilayer ice has a major contribution to water transport through 2D nanochannels.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 5.7
Times cited: 35
DOI: 10.1021/ACS.JPCLETT.0C01739
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“Purple non-sulphur bacteria and plant production: benefits for fertilization, stress resistance and the environment”. Sakarika M, Spanoghe J, Sui Y, Wambacq E, Grunert O, Haesaert G, Spiller M, Vlaeminck SE, Microbial biotechnology 13, 1336 (2020). http://doi.org/10.1111/1751-7915.13474
Abstract: Purple non-sulphur bacteria (PNSB) are phototrophic microorganisms, which increasingly gain attention in plant production due to their ability to produce and accumulate high-value compounds that are beneficial for plant growth. Remarkable features of PNSB include the accumulation of polyphosphate, the production of pigments and vitamins and the production of plant growth-promoting substances (PGPSs). Scattered case studies on the application of PNSB for plant cultivation have been reported for decades, yet a comprehensive overview is lacking. This review highlights the potential of using PNSB in plant production, with emphasis on three key performance indicators (KPIs): fertilization, resistance to stress (biotic and abiotic) and environmental benefits. PNSB have the potential to enhance plant growth performance, increase the yield and quality of edible plant biomass, boost the resistance to environmental stresses, bioremediate heavy metals and mitigate greenhouse gas emissions. Here, the mechanisms responsible for these attributes are discussed. A distinction is made between the use of living and dead PNSB cells, where critical interpretation of existing literature revealed the better performance of living cells. Finally, this review presents research gaps that remain yet to be elucidated and proposes a roadmap for future research and implementation paving the way for a more sustainable crop production.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 5.7
Times cited: 10
DOI: 10.1111/1751-7915.13474
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“Near-Edge Ligand Stripping and Robust Radiative Exciton Recombination in CdSe/CdS Core/Crown Nanoplatelets”. Leemans J, Singh S, Li C, Ten Brinck S, Bals S, Infante I, Moreels I, Hens Z, Journal Of Physical Chemistry Letters 11, 3339 (2020). http://doi.org/10.1021/acs.jpclett.0c00870
Abstract: We address the relation between surface chemistry and optoelectronic properties in semiconductor nanocrystals using core/crown CdSe/CdS nanoplatelets passivated by cadmium oleate (Cd(Ol)2) as model systems. We show that addition of butylamine to a nanoplatelet (NPL) dispersion maximally displaces ∼40% of the original Cd(Ol)2 capping. On the basis of density functional theory simulations, we argue that this behavior reflects the preferential displacement of Cd(Ol)2 from (near)-edge surface sites. Opposite from CdSe core NPLs, core/crown NPL dispersions can retain 45% of their initial photoluminescence efficiency after ligand displacement, while radiative exciton recombination keeps dominating the luminescent decay. Using electron microscopy observations, we assign this robust photoluminescence to NPLs with a complete CdS crown, which prevents charge carrier trapping in the near-edge surface sites created by ligand displacement. We conclude that Z-type ligands such as cadmium carboxylates can provide full electronic passivation of (100) facets yet are prone to displacement from (near)-edge surface sites.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.7
Times cited: 24
DOI: 10.1021/acs.jpclett.0c00870
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“Clogging and unclogging of hydrocarbon-contaminated nanochannels”. Javdani Z, Hassani N, Faraji F, Zhou R, Sun C, Radha B, Neyts E, Peeters FM, Neek-Amal M, The journal of physical chemistry letters 13, 11454 (2022). http://doi.org/10.1021/ACS.JPCLETT.2C03016
Abstract: The recent advantages of the fabrication of artificial nanochannels enabled new research on the molecular transport, permeance, and selectivity of various gases and molecules. However, the physisorption/chemisorption of the unwanted molecules (usually hydrocarbons) inside nanochannels results in the alteration of the functionality of the nanochannels. We investigated contamination due to hydrocarbon molecules, nanochannels made of graphene, hexagonal boron nitride, BC2N, and molybdenum disulfide using molecular dynamics simulations. We found that for a certain size of nanochannel (i.e., h = 0.7 nm), as a result of the anomalous hydrophilic nature of nanochannels made of graphene, the hydrocarbons are fully adsorbed in the nanochannel, giving rise to full uptake. An increasing temperature plays an important role in unclogging, while pressure does not have a significant role. The results of our pioneering work contribute to a better understanding and highlight the important factors in alleviating the contamination and unclogging of nanochannels, which are in good agreement with the results of recent experiments.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 5.7
DOI: 10.1021/ACS.JPCLETT.2C03016
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“Metal-polymer heterojunction in colloidal-phase plasmonic catalysis”. Rogolino A, Claes N, Cizaurre J, Marauri A, Jumbo-Nogales A, Lawera Z, Kruse J, Sanroman-Iglesias M, Zarketa I, Calvo U, Jimenez-Izal E, Rakovich YP, Bals S, Matxain JM, Grzelczak M, The journal of physical chemistry letters 13, 2264 (2022). http://doi.org/10.1021/ACS.JPCLETT.1C04242
Abstract: Plasmonic catalysis in the colloidal phase requires robust surface ligands that prevent particles from aggregation in adverse chemical environments and allow carrier flow from reagents to nanoparticles. This work describes the use of a water-soluble conjugated polymer comprising a thiophene moiety as a surface ligand for gold nanoparticles to create a hybrid system that, under the action of visible light, drives the conversion of the biorelevant NAD+ to its highly energetic reduced form NADH. A combination of advanced microscopy techniques and numerical simulations revealed that the robust metal-polymer heterojunction, rich in sulfonate functional groups, directs the interaction of electron-donor molecules with the plasmonic photocatalyst. The tight binding of polymer to the gold surface precludes the need for conventional transition-metal surface cocatalysts, which were previously shown to be essential for photocatalytic NAD(+) reduction but are known to hinder the optical properties of plasmonic nanocrystals. Moreover, computational studies indicated that the coating polymer fosters a closer interaction between the sacrificial electron-donor triethanolamine and the nanoparticles, thus enhancing the reactivity.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.7
Times cited: 1
DOI: 10.1021/ACS.JPCLETT.1C04242
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“Unlocking the genomic potential of aerobes and phototrophs for the production of nutritious and palatable microbial food without arable land or fossil fuels”. Alloul A, Spanoghe J, Machado D, Vlaeminck SE, Microbial biotechnology 15, 6 (2022). http://doi.org/10.1111/1751-7915.13747
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.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 5.7
DOI: 10.1111/1751-7915.13747
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“Enrichment and aggregation of purple non-sulfur bacteria in a mixed-culture sequencing-batch photobioreactor for biological nutrient removal from wastewater”. Cerruti M, Stevens B, Ebrahimi S, Alloul A, Vlaeminck SE, Weissbrodt DG, Frontiers in Bioengineering and Biotechnology 8, 557234 (2020). http://doi.org/10.3389/FBIOE.2020.557234
Abstract: Mixed-culture biotechnologies are widely used to capture nutrients from wastewater. Purple non-sulfur bacteria (PNSB), a guild of anoxygenic photomixotrophic organisms, rise interest for their ability to directly assimilate nutrients in the biomass. One challenge targets the aggregation and accumulation of PNSB biomass to separate it from the treated water. Our aim was to enrich and produce a concentrated, fast-settling PNSB biomass with high nutrient removal capacity in a 1.5-L, stirred-tank, anaerobic sequencing-batch photobioreactor (SBR). PNSB were rapidly enriched after inoculation with activated sludge at 0.1 gVSS L–1 in a first batch of 24 h under continuous irradiance of infrared (IR) light (>700 nm) at 375 W m–2, with Rhodobacter reaching 54% of amplicon sequencing read counts. SBR operations with decreasing hydraulic retention times (48 to 16 h, i.e., 1–3 cycles d–1) and increasing volumetric organic loading rates (0.2–1.3 kg COD d–1 m–3) stimulated biomass aggregation, settling, and accumulation in the system, reaching as high as 3.8 g VSS L–1. The sludge retention time (SRT) increased freely from 2.5 to 11 days. Acetate, ammonium, and orthophosphate were removed up to 96% at a rate of 1.1 kg COD d–1 m–3, 77% at 113 g N d–1 m–3, and 73% at 15 g P d–1 m–3, respectively, with COD:N:P assimilation ratio of 100:6.7:0.9 m/m/m. SBR regime shifts sequentially selected for Rhodobacter (90%) under shorter SRT and non-limiting concentration of acetate during reaction phases, for Rhodopseudomonas (70%) under longer SRT and acetate limitation during reaction, and Blastochloris (10%) under higher biomass concentrations, underlying competition for substrate and photons in the PNSB guild. With SBR operations we produced a fast-settling biomass, highly (>90%) enriched in PNSB. A high nutrient removal was achieved by biomass assimilation, reaching the European nutrient discharge limits. We opened further insights on the microbial ecology of PNSB-based processes for water resource recovery.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 5.7
DOI: 10.3389/FBIOE.2020.557234
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“Unveiling the electronic structure of pseudotetragonal WO₃, thin films”. Mazzola F, Hassani H, Amoroso D, Chaluvadi SK, Fujii J, Polewczyk V, Rajak P, Koegler M, Ciancio R, Partoens B, Rossi G, Vobornik I, Ghosez P, Orgiani P, The journal of physical chemistry letters 14, 7208 (2023). http://doi.org/10.1021/ACS.JPCLETT.3C01546
Abstract: WO3 isa 5d compound that undergoes severalstructuraltransitions in its bulk form. Its versatility is well-documented,with a wide range of applications, such as flexopiezoelectricity,electrochromism, gating-induced phase transitions, and its abilityto improve the performance of Li-based batteries. The synthesis ofWO(3) thin films holds promise in stabilizing electronicphases for practical applications. However, despite its potential,the electronic structure of this material remains experimentally unexplored.Furthermore, its thermal instability limits its use in certain technologicaldevices. Here, we employ tensile strain to stabilize WO3 thin films, which we call the pseudotetragonal phase, and investigateits electronic structure using a combination of photoelectron spectroscopyand density functional theory calculations. This study reveals theFermiology of the system, notably identifying significant energy splittingsbetween different orbital manifolds arising from atomic distortions.These splittings, along with the system's thermal stability,offer a potential avenue for controlling inter- and intraband scatteringfor electronic applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 5.7
DOI: 10.1021/ACS.JPCLETT.3C01546
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“Accurate Reaction Probabilities for Translational Energies on Both Sides of the Barrier of Dissociative Chemisorption on Metal Surfaces”. Gerrits N, Jackson B, Bogaerts A, The Journal of Physical Chemistry Letters 15, 2566 (2024). http://doi.org/10.1021/acs.jpclett.3c03408
Abstract: Molecular dynamics simulations are essential for a better understanding of dissociative chemisorption on metal surfaces, which is often the rate-controlling step in heterogeneous and plasma catalysis. The workhorse quasi-classical trajectory approach ubiquitous in molecular dynamics is able to accurately predict reactivity only for high translational and low vibrational energies. In contrast, catalytically relevant conditions generally involve low translational and elevated vibrational energies. Existing quantum dynamics approaches are intractable or approximate as a result of the large number of degrees of freedom present in molecule−metal surface reactions. Here, we extend a ring polymer molecular dynamics approach to fully include, for the first time, the degrees of freedom of a moving metal surface. With this approach, experimental sticking probabilities for the dissociative chemisorption of methane on Pt(111) are reproduced for a large range of translational and vibrational energies by including nuclear quantum effects and employing full-dimensional simulations.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 5.7
DOI: 10.1021/acs.jpclett.3c03408
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“Advanced TEM investigation of the plasticity mechanisms in nanocrystalline freestanding palladium films with nanoscale twins”. Wang B, Idrissi H, Galceran M, Colla MS, Turner S, Hui S, Raskin JP, Pardoen T, Godet S, Schryvers D, International journal of plasticity 37, 140 (2012). http://doi.org/10.1016/j.ijplas.2012.04.003
Abstract: Nanocrystalline palladium thin films deposited by electron-beam evaporation and deformed by on-chip tensile testing reveal a surprisingly large strain hardening capacity when considering the small similar to 25 nm grain size. The as-grown films contain several coherent single and multifold twin boundaries. The coherency of the twin boundaries considerably decreases with deformation due to dislocation/twin boundary interactions. These reactions are described based on a detailed analysis of the number and the type of dislocations located at the twin boundaries using high-resolution TEM, including aberration corrected microscopy. Sessile Frank dislocations were observed at the twin/matrix interfaces, explaining the loss of the TB coherency due to the Burgers vector pointing out of the twinning plane. Grain boundary mediated processes were excluded as a mechanism dominating the plastic deformation based on the investigation of the grain size distribution as well as the crystallographic texture using Automated Crystallographic Orientation Indexation TEM. Other factors influencing the plastic deformation such as impurities and the presence of a native passivation oxide layer at the surface of the films were investigated using analytical TEM. The twin boundaries observed in the present work partly explain the high strain hardening capacity by providing both increasing resistance to dislocation motion with deformation and a source for dislocation multiplication. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.702
Times cited: 44
DOI: 10.1016/j.ijplas.2012.04.003
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“Transmission electron microscopy investigation of dislocation slip during superelastic cycling of NiTi wires”. Delville R, Malard B, Pilch J, Sittner P, Schryvers D, International journal of plasticity 27, 282 (2011). http://doi.org/10.1016/j.ijplas.2010.05.005
Abstract: Superelastic deformation of thin NiTi wires containing various nanograined microstructures was investigated by tensile cyclic loading with in situ evaluation of electric resistivity. Defects created by the superelastic cycling in these wires were analyzed by transmission electron microscopy. The role of dislocation slip in superelastic deformation is discussed. NiTi wires having finest microstructures (grain diameter <100 nm) are highly resistant against dislocation slip, while those with fully recrystallized microstructure and grain size exceeding 200 nm are prone to dislocation slip. The density of the observed dislocation defects increases significantly with increasing grain size. The upper plateau stress of the superelastic stressstrain curves is largely grain size independent from 10 up to 1000 nm. It is hence claimed that the HallPetch relationship fails for the stress-induced martensitic transformation in this grain size range. It is proposed that dislocation slip taking place during superelastic cycling is responsible for the accumulated irreversible strains, cyclic instability and degradation of functional properties. No residual martensite phase was found in the microstructures of superelastically cycled wires by TEM and results of the in situ electric resistance measurements during straining also indirectly suggest that none or very little martensite phase remains in the studied cycled superelastic wires after unloading. The accumulation of dislocation defects, however, does not prevent the superelasticity. It only affects the shape of the stressstrain response, makes it unstable upon cycling and changes the deformation mode from localized to homogeneous. The activity of dislocation slip during superelastic deformation of NiTi increases with increasing test temperature and ultimately destroys the superelasticity as the plateau stress approaches the yield stress for slip. Deformation twins in the austenite phase ({1 1 4} compound twins) were frequently found in cycled wires having largest grain size. It is proposed that they formed in the highly deformed B19′ martensite phase during forward loading and are retained in austenite after unloading. Such twinning would represent an additional deformation mechanism of NiTi yielding residual irrecoverable strains.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.702
Times cited: 157
DOI: 10.1016/j.ijplas.2010.05.005
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“Single layer graphene controlled surface and bulk indentation plasticity in copper”. Bahrami F, Hammad M, Fivel M, Huet B, D'Haese C, Ding L, Nysten B, Idrissi H, Raskin JP, Pardoen T, International Journal Of Plasticity 138, 102936 (2021). http://doi.org/10.1016/J.IJPLAS.2021.102936
Abstract: The impact of graphene reinforcement on the mechanical properties of metals has been a subject of intense investigation over the last decade in surface applications to mitigate the impact of tribological loadings or for strengthening purposes when dispersed into a bulk material. Here, the effect on the plastic indentation response of a single graphene layer grown on copper is analyzed for two configurations: one with graphene at the surface, the other with graphene sandwiched under a 100 nm thick copper cap layer. Nanoindentation under both displacement and load control conditions show both earlier and shorter pop-in excursions compared to systems without graphene. Atomic force microscopy reveals much smoother pile-ups with no slip traces in the presence of a surface graphene layer. The configuration with the intercalated graphene layer appears as an ideal elementary system to address bulk hardening mechanisms by indentation testing. Transmission electron microscopy (TEM) cross-sections below indents show more diffuse and homogeneous dislocation activity in the presence of graphene. 3D dislocation dynamics simulations allow unraveling of the origin of these 3D complex phenomena and prove that the collective dislocation mechanisms are dominantly controlled by the strong back stress caused by the graphene barrier. These results provide a quantitative understanding of the impact of graphene on dislocation mechanisms for both surface and bulk applications, but with an impact that is not as large as anticipated from other studies or general literature claims.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.702
DOI: 10.1016/J.IJPLAS.2021.102936
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“Valorization of thermal treatment residues in enhanced landfill mining : environmental and economic evaluation”. Danthurebandara M, Van Passel S, Machiels L, Van Acker K, Journal Of Cleaner Production 99, 275 (2015). http://doi.org/10.1016/J.JCLEPRO.2015.03.021
Abstract: Enhanced Landfill Mining is an innovative concept which allows the recovery of land, re-introduction of materials to the material cycles and recovery of energy from a considerably large stock of resources held in landfills. Plasma gasification is a viable candidate for combined energy and material valorization in the framework of Enhanced landfill Mining. Besides energy production, plasma gasification also delivers an environmentally stable vitrified residue called plasmastone, which can be converted into building materials. This paper presents an environmental and economic evaluation of the valorization of thermal treatment residues (plasmastone) in the context of Enhanced Landfill Mining. The most common valorization route, that is, the treatment of plasmastone via production of aggregates, is compared with two other possible, higher added value applications, which are inorganic polymer production and blended cement production. The evaluation is based on life cycle assessment and life cycle costing. The study suggests that the environmental and economic performances of the valorization routes depend mainly on the quality and quantity of the final products produced from a certain amount of plasmastone. The materials with the greatest contribution to potential global warming and to the net present value of the valorization scenarios are the process input materials of sodium silicate, sodium hydroxide and cement. The study concludes that the plasmastone valorization via inorganic polymer production yields higher environmental benefits, while the blended cement production provides higher economic profits. Plasmastone valorization via aggregates production does not yield economic or environmental benefits. Given the trade-off between environmental and economic performances, we conclude that the decisions regarding the selection of appropriate valorization routes should be made cautiously to obtain optimal environmental benefits and economic profits. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 5.715
Times cited: 17
DOI: 10.1016/J.JCLEPRO.2015.03.021
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“The economics of enhanced landfill mining : private and societal performance drivers”. Van Passel S, Dubois M, Eyckmans J, de Gheldere S, Ang F, Jones PT, Van Acker K, Journal Of Cleaner Production 55, 92 (2013). http://doi.org/10.1016/J.JCLEPRO.2012.03.024
Abstract: This paper addresses the economics of Enhanced Landfill Mining (ELFM) both from a private point of view as well as from a society perspective. The private potential is assessed using a case study for which an investment model is developed to identify the impact of a broad range of parameters on the profitability of ELFM. We found that especially variations in Waste-to-Energy (WtE efficiency, electricity price, CO2-price, WtE investment and operational costs) and ELFM support explain the variation in economic profitability measured by the Internal Rate of Return. To overcome site-specific parameters we also evaluated the regional ELFM potential for the densely populated and industrial region of Flanders (north of Belgium). The total number of potential ELFM sites was estimated using a 5-step procedure and a simulation tool was developed to trade-off private costs and benefits. The analysis shows that there is a substantial economic potential for ELFM projects on the wider regional level. Furthermore, this paper also reviews the costs and benefits from a broader perspective. The carbon footprint of the case study was mapped in order to assess the project's net impact in terms of greenhouse gas emissions. Also the impacts of nature restoration, soil remediation, resource scarcity and reduced import dependence were valued so that they can be used in future social cost-benefit analysis. Given the complex trade-off between economic, social and environmental issues of ELFM projects, we conclude that further refinement of the methodological framework and the development of the integrated decision tools supporting private and public actors, are necessary. (c) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 5.715
Times cited: 65
DOI: 10.1016/J.JCLEPRO.2012.03.024
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“Techno-economic assessment of fast pyrolysis for the valorization of short rotation coppice cultivated for phytoextraction”. Kuppens T, Van Dael M, Vanreppelen K, Thewys T, Yperman J, Carleer R, Schreurs S, Van Passel S, Journal Of Cleaner Production 88, 336 (2015). http://doi.org/10.1016/J.JCLEPRO.2014.07.023
Abstract: The main barrier in the commercialization of phytoextraction as a sustainable alternative for remediating metal contaminated soils is its long time period, which can be countered by biomass valorization. From an environmental point of view, fast pyrolysis of the biomass is promising because its lower process temperature prevents metal volatilization. The remaining question is whether fast pyrolysis is also preferred from an economic point of view. Therefore, a techno-economic assessment of fast pyrolysis has been performed for a case study in the Campine region in Belgium. For this region, willow trees cultivated in short rotation have the right characteristics to serve as a phytoextracting crop. A techno-economic assessment requires by definition a multidisciplinary approach. The problem statement urges for a focus on the economic profitability from the viewpoint of an investor, including economic risk analysis. Fast pyrolysis seems more profitable than gasification. The profit is dependent on the scale of operation, the policy support (subsidies) and the oil yield. The economic risk can be reduced by increasing the scale of operation by means of complementing feedstocks, and by valorization of the char byproduct by subsequent processing to activated carbon. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering Management (ENM)
Impact Factor: 5.715
Times cited: 36
DOI: 10.1016/J.JCLEPRO.2014.07.023
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“'On tomorrow's grounds' : Flemish agriculture in 2030: a case of participatory translation of sustainability principles into a vision for the future”. Nevens F, Dessein J, Meul M, Rogge E, Verbruggen I, Mulier A, Van Passel S, Lepoutre J, Hongenaert M, Journal Of Cleaner Production 16, 1062 (2008). http://doi.org/10.1016/J.JCLEPRO.2007.06.007
Abstract: In Flanders (Belgium) there is an obvious lack of clear long-term vision on sustainable development, for society as a whole as well as for the individual sectors of (economic) activity. In this paper we present the first results of a process of vision development for Flemish agriculture, called On tomorrow's grounds. The initiative, taken by Stedula (the Flemish Policy Research Centre for Sustainable Agriculture), shows that discovering core values, stating a concise mission, establishing guiding core principles and working with vivid descriptions of envisaged future systems seem indispensable elements to develop a vision that inspires and mobilizes people and that, eventually, stands a chance of being anchored in the sector's or organisation's culture. The principal method of working of the project was a multi-stakeholder process (MSP) focussed on dialogue. During five extensive stakeholder meetings, representatives of farmers, service industries, food distribution, education, government, research, consumers and NGO's participated in a constructive dialogue on values and mission, principles and two vivid descriptions of envisioned future farms. The concept of the project was welcomed and supported by the Flemish Minister-President and by the Belgian federal state secretary for sustainable development.
Keywords: A1 Journal article; Economics
Impact Factor: 5.715
Times cited: 13
DOI: 10.1016/J.JCLEPRO.2007.06.007
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“Environmental assessment of waste feedstock mono-dimensional and bio-refinery systems : combining manure co-digestion and municipal waste anaerobic digestion”. Moretti M, Van Dael M, Malina R, Van Passel S, Journal Of Cleaner Production 171, 954 (2018). http://doi.org/10.1016/J.JCLEPRO.2017.10.097
Abstract: Organic municipal solid waste (OMSW) as a feedstock for energy recovery and material recycling offers the potential to reduce environmental impacts from energy production while displacing emission intensive waste management strategies such as landfills. This paper quantifies the environmental impact of anaerobic digestion of local, residual biomass. A life-cycle assessment was jointly performed for two scenarios for the biological treatment of local organic municipal solid waste and pig manure in the Netherlands. Scenario 1 was a separate treatment using anaerobic digestion, and Scenario 2 was a bio-refinery system that integrates anaerobic digestion of organic, municipal solid waste, and co digestion of pig manure and other organic co-substrates \. For both scenarios, electricity and heat are generated using a combined heat and power engine. The bio-refinery system (Scenario 2) contribution to climate change resulted in 0.16 Mt CO2 eq./yr, which is lower than the 0.17 Mt CO2 eq./yr of Scenario 1. Both scenarios are found to be beneficial with regard to resource depletion and human toxicity. The integration of organic waste and manure anaerobic digestion has no effect on acidification and terrestrial eutrophication impact categories, resulting in 43.59 AE eq. and 86.33 AE eq. for Scenario 1 and 43.58 AE eq. and 86.30 AE eq. for Scenario 2. Moreover, Scenario 2 yields 18% lower emissions than those from natural gas derived electricity in the Netherlands. The biorefinery system represents an opportunity to improve organic waste-management strategies, at the same time as reducing the environmental impact from energy production and the costs for surplus manure disposal by producing high-quality commodities that can be traded on the market. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 5.715
Times cited: 12
DOI: 10.1016/J.JCLEPRO.2017.10.097
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“Enhanced landfill mining in view of multiple resource recovery : a critical review”. Jones PT, Geysen D, Tielemans Y, Van Passel S, Pontikes Y, Blanpain B, Quaghebeur M, Hoekstra N, Journal Of Cleaner Production 55, 45 (2013). http://doi.org/10.1016/J.JCLEPRO.2012.05.021
Abstract: In a circular economy material loops are closed by recycling of pre-consumer manufacturing scrap/residues, urban mining of End-of-Life products and landfill mining of historic (and future) urban waste streams. However, in the past landfill mining was not performed with a focus on resource recovery. This paper addresses this gap by introducing the concept of Enhanced Landfill Mining, defined as the safe conditioning, excavation and integrated valorization of landfilled waste streams as both materials and energy, using innovative transformation technologies and respecting the most stringent social and ecological criteria. The feasibility of ELFM is studied by synthesizing the research on the Closing the Circle project, the first ELFM project targeting the 18 million metric ton landfill in Houthalen-Helchteren in the East of Belgium. It is argued that Environmental Impact Assessments of ELFM projects should be wide in scope and time. Embedded in a broad resource management perspective, the worldwide potential of ELFM is highlighted, in terms of climate gains, materials and energy utilization, job creation and land reclamation. The potential is quantified for the EU-27 with its 150,000-500,000 landfills. However, for ELFM to reach its full potential, strategic policy decisions and tailored support systems, including combined incentives for material recycling, energy utilization and nature restoration, are required. (c) 2012 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 5.715
Times cited: 144
DOI: 10.1016/J.JCLEPRO.2012.05.021
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“Assessment of the sustainability guidelines of EU Renewable Energy Directive : the case of biorefineries”. Maes D, Van Dael M, Vanheusden B, Goovaerts L, Reumerman P, Luzardo NM, Van Passel S, Journal Of Cleaner Production 88, 61 (2015). http://doi.org/10.1016/J.JCLEPRO.2014.04.051
Abstract: Sustainability guidelines can help to safeguard the sustainable use of biological materials. When these guidelines are legally prescribed, their influence on the economic viability of bioenergy, biofuel and bioliquid projects is increased substantially, through their impact on national subsidy regimes and international trade. One of the key examples is the European directive 2009/28/EC, or the Renewable Energy Directive (RED), and the related COM/2010/11 that integrate guidelines for calculating greenhouse gas impact for various bioenergy pathways. This paper looks further into the sustainability results when influenced by principal decisions that are legally open for debate. Therefore, a concise review is conducted of the legal state-of-the-art on whether a product is waste or not. The review pinpoints uncertainty, leading to four potential legal scenarios. The sustainability of a complex biorefinery is analysed for each scenario. The results show (i) a high sensitivity to the principal decisions on the nature of waste materials in the scenarios, and (ii) to the definition of boundaries between the processes. More detailed rules for the application of the RED guidelines are needed, and should be complemented with methods specifically targeting all relevant sustainability aspects, thereby enhancing the overall understanding of the sustainability of the process. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Economics; Engineering Management (ENM)
Impact Factor: 5.715
Times cited: 25
DOI: 10.1016/J.JCLEPRO.2014.04.051
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“The conceptualization of societal impacts of landfill mining : a system dynamics approach”. Einhäupl P, Van Acker K, Peremans H, Van Passel S, Journal Of Cleaner Production 296, 126351 (2021). http://doi.org/10.1016/J.JCLEPRO.2021.126351
Abstract: Landfill mining (LFM) refers to the excavation and processing of formerly buried waste streams. It offers significant environmental and societal benefits through the mitigation of greenhouse gas emissions or the reduction of long-term waste management costs. LFM’s profitability, however, is still in question and public investment support might be necessary to fully exploit its potential. To enable decision-makers to identify the best solutions for a landfill site, societal impacts of LFM still have to be investigated. Throughout relevant literature, societal impacts of LFM projects have only selectively been studied and it remains unclear if and which benefits justify policy interventions. This paper firstly provides a comprehensive conceptualization of the societal impact of an LFM project and dives into the underlying societal context of this emerging industry. It disentangles formerly identified burdens and benefits by applying a system dynamics approach to LFM research. Based on this approach, four causal loop diagrams are presented showing how LFM is embedded into its societal context, analyzing the composition of the net societal impact of an LFM project, the mechanisms influencing LFM’s public acceptance, and the dynamics of the market acceptance of LFM products. Key variables and leverage points have been identified, such as (i) technology choices influencing avoided impacts from the mitigations of primary resource consumption, since many societal impacts are closely related to environmental impacts, (ii) a timely and broad stakeholder involvement to prevent project opposition, and (iii) the after-use of the mined landfill, generating a major part of the local and regional societal benefits but also creating potential conflicts between stakeholder interests. Key intradimensional trade-offs and potential conflicts were identified in (i) spatial and (ii) temporal risk distribution, (iii) conflicting societal goals of the after-use such as job creations and recreation, as well as (iv) material and energy recuperation. These findings provide important insights for LFM decision-makers and can help to implement this emerging industry in a sustainable way.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 5.715
DOI: 10.1016/J.JCLEPRO.2021.126351
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“Ex-ante LCA of emerging carbon steel slag treatment technologies : fast forwarding lab observations to industrial-scale production”. Buyle M, Maes B, Van Passel S, Boonen K, Vercalsteren A, Audenaert A, Journal Of Cleaner Production 313, 127921 (2021). http://doi.org/10.1016/J.JCLEPRO.2021.127921
Abstract: The valuable properties of carbon steel slag are currently underexploited. To date, research mainly focusses on valorising a single property of the slag. In this study an ex-ante life cycle assessment (LCA) was applied to evaluate the environmental profile of a novel technological pathway aimed at the extraction of chromium from carbon steel slag in combination with high quality valorisation of the residual matrix material. A comparison with current practice was made, not only by calculating the environmental impact of the lab scale observations, but more importantly by estimating the impact on an industrial scale. Practical guidance on ex-ante LCA is limited, so this study contributes by incorporating simulations on thermodynamic behaviour, complemented with empirical calculation rules and including information derived from similar technologies to perform the upscaling. These principles of ex-ante LCA were applied to the lab results of two consecutive research iterations. Substantial improvements of the environmental profile were observed: ex-ante results turned out to be a factor 20 lower compared to the results from the lab observations after the first iteration and had decreased by a factor 2 compared to the small pilot scale of the second iteration. All upscaled results are better than those from the worst case reference scenario (landfill). Based on the experience gained after this iterative research cycle, a practical recommendation is that at a low technology readiness level using more simple calculation rules in combination with a flowsheet based on elementary design principles for processes at an industrial scale is a more efficient way of modelling compared to a fully-fledged process design from the start.
Keywords: A1 Journal article; Engineering sciences. Technology; Energy and Materials in Infrastructure and Buildings (EMIB)
Impact Factor: 5.715
DOI: 10.1016/J.JCLEPRO.2021.127921
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“Rethinking resilient agriculture : from Climate-Smart Agriculture to Vulnerable-Smart Agriculture”. Azadi H, Moghaddam SM, Burkart S, Mahmoudi H, Van Passel S, Kurban A, Lopez-Carr D, Journal Of Cleaner Production 319, 128602 (2021). http://doi.org/10.1016/J.JCLEPRO.2021.128602
Abstract: Climate-Smart Agriculture (CSA) is seeking to overcome the food security problem and develop rural livelihoods while minimizing negative impacts on the environment. However, when such synergies exist, the situation of small-scale farmers is often overlooked, and they are unable to implement new practices and technologies. Therefore, the main aim of this study is to improve CSA by adding the neglected but very important element “small-scale farmer”, and introduce Vulnerable-Smart Agriculture (VSA) as a complete version of CSA. VSA indicates, based on the results of this study, that none of the decisions made by policymakers can be realistic and functional as long as the voice of the farmers influenced by their decisions is not heard. Therefore, to identify different levels for possible interventions and develop VSA monitoring indicators, a new conceptual framework needs to be developed. This study proposed such a framework consisting of five elements: prediction of critical incidents by farmers, measuring the consequences of incidents, identifying farmers' coping strategies, assessing farmers' livelihood capital when facing an incident, and adapting to climate incidents. The primary focus of this study is on farmers' learning and operational preparation to deal with tension and disasters at farm level. Understanding the implications of threats from climate change and the recognizing of coping mechanisms will contribute to an increase in understanding sustainable management.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 5.715
DOI: 10.1016/J.JCLEPRO.2021.128602
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“VEGF-targeted magnetic nanoparticles for MRI visualization of brain tumor”. Abakumov MA, Nukolova NV, Sokolsky-Papkov M, Shein SA, Sandalova TO, Vishwasrao HM, Grinenko NF, Gubsky IL, Abakumov AM, Kabanov AV, Chekhonin VP;, Nanomedicine: nanotechnology, biology and medicine 11, 825 (2015). http://doi.org/10.1016/j.nano.2014.12.011
Abstract: This work is focused on synthesis and characterization of targeted magnetic nanoparticles as magnetic resonance imaging (MRI) agents for in vivo visualization of gliomas. Ferric oxide (Fe3O4) cores were synthesized by thermal decomposition and coated with bovine serum albumin (BSA) to form nanoparticles with D-eff of 53 +/- 9 nm. The BSA was further cross-linked to improve colloidal stability. Monoclonal antibodies against vascular endothelial growth factor (mAbVEGF) were covalently conjugated to BSA through a polyethyleneglycol linker. Here we demonstrate that 1) BSA coated nanoparticles are stable and non-toxic to different cells at concentration up to 2.5 mg/mL; 2) conjugation of monoclonal antibodies to nanoparticles promotes their binding to VEGF-positive glioma C6 cells in vitro; 3) targeted nanoparticles are effective in MRI visualization of the intracranial glioma. Thus, mAbVEGF-targeted BSA-coated magnetic nanoparticles are promising MRI contrast agents for glioma visualization. (C) 2015 Elsevier Inc. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.72
Times cited: 62
DOI: 10.1016/j.nano.2014.12.011
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“An accurate parameterization for scattering factors, electron densities and electrostatic potentials for neutral atoms that obey all physical constraints”. Lobato Hoyos IP, van Dyck D, Acta crystallographica: section A: foundations of crystallography 70, 636 (2014). http://doi.org/10.1107/S205327331401643X
Abstract: An efficient procedure and computer program are outlined for fitting numerical X-ray and electron scattering factors with the correct inclusion of all physical constraints. The numerical electron scattering factors have been parameterized using five analytic non-relativistic hydrogen electron scattering factors as basis functions for 103 neutral atoms of the periodic table. The inclusion of the correct physical constraints in the electron scattering factor and its derived quantities allows the use of the new parameterization in different fields. In terms of quality of the fit, the proposed parameterization of the electron scattering factor is one order of magnitude better than the previous analytic fittings.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 5.725
Times cited: 19
DOI: 10.1107/S205327331401643X
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“Computation and parametrization of the temperature dependence of Debye-Waller factors for group IV, III-V and II-VI semiconductors”. Schowalter M, Rosenauer A, Titantah JT, Lamoen D, Acta crystallographica: section A: foundations of crystallography 65, 5 (2009). http://doi.org/10.1107/S0108767308031437
Abstract: We calculated the temperature dependence of the Debye-Waller factors for a variety of group IV, III-V and II-VI semiconductors from 0.1 to 1000 K. The approach used to fit the temperature dependence is described and resulting fit parameters are tabulated for each material. The Debye-Waller factors are deduced from generalized phonon densities of states which were derived from first principles using the WIEN2k and the ABINIT codes.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.725
Times cited: 51
DOI: 10.1107/S0108767308031437
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