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Author | Bahnamiri, O.S.; Verheyen, C.; Snyders, R.; Bogaerts, A.; Britun, N. | ||||
Title | Nitrogen fixation in pulsed microwave discharge studied by infrared absorption combined with modelling | Type | A1 Journal Article;nitrogen fixation | ||
Year | 2021 | Publication | Plasma Sources Science & Technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 30 | Issue | 6 | Pages | 065007 |
Keywords | A1 Journal Article;nitrogen fixation; pulsed microwave discharge; FTIR spectroscopy; discharge modelling; vibrational excitation; NO yield; energy cost; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | A pulsed microwave surfaguide discharge operating at 2.45 GHz was used for the conversion of molecular nitrogen into valuable compounds in several gas mixtures: N2 :O2 , N2 :O2 :CO2 and N2 :CO2 . The ro-vibrational absorption bands of the molecular species were monitored by a Fourier transform infrared apparatus in the post-discharge region in order to evaluate the relative number density of species, specifically NO production. The effects of specific energy input, pulse frequency, gas flow fraction, gas admixture and gas flow rate were studied for better understanding and optimization of the NO production yield and the corresponding energy cost (EC). By both the experiment and modelling, a highest NO yield is obtained at N2 :O2 (1:1) gas ratio in N2 :O2 mixture. The NO yield reveals a small growth followed by saturation when pulse repetition frequency increases. The energy efficiency start decreasing after the energy input reaches about 5 eV/molec, whereas the NO yield rises steadily at the same time. The lowest EC of about 8 MJ mol−1 corresponding to the yield and the energy efficiency of about 7% and 1% are found, respectively, in an optimum discharge condition in our case. | ||||
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Language | Wos | 000659671000001 | Publication Date | 2021-06-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0963-0252 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.302 | Times cited | Open Access | OpenAccess | |
Notes | Fonds De La Recherche Scientifique—FNRS, EOS O005118F ; The research is supported by the FNRS-FWO project ‘NITROPLASM’, EOS O005118F. O Samadi also acknowledges PhD student F Manaigo for cooperation in doing the additional measurements. | Approved | Most recent IF: 3.302 | ||
Call Number | PLASMANT @ plasmant @c:irua:179170 | Serial | 6798 | ||
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Author | Skorikov, A.; Heyvaert, W.; Albecht, W.; Pelt, D.M.; Bals, S. | ||||
Title | Deep learning-based denoising for improved dose efficiency in EDX tomography of nanoparticles | Type | A1 Journal article | ||
Year | 2021 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 13 | Issue | Pages | 12242-12249 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | The combination of energy-dispersive X-ray spectroscopy (EDX) and electron tomography is a powerful approach to retrieve the 3D elemental distribution in nanomaterials, providing an unprecedented level of information for complex, multi-component systems, such as semiconductor devices, as well as catalytic and plasmonic nanoparticles. Unfortunately, the applicability of EDX tomography is severely limited because of extremely long acquisition times and high electron irradiation doses required to obtain 3D EDX reconstructions with an adequate signal-to-noise ratio. One possibility to address this limitation is intelligent denoising of experimental data using prior expectations about the objects of interest. Herein, this approach is followed using the deep learning methodology, which currently demonstrates state-of-the-art performance for an increasing number of data processing problems. Design choices for the denoising approach and training data are discussed with a focus on nanoparticle-like objects and extremely noisy signals typical for EDX experiments. Quantitative analysis of the proposed method demonstrates its significantly enhanced performance in comparison to classical denoising approaches. This allows for improving the tradeoff between the reconstruction quality, acquisition time and radiation dose for EDX tomography. The proposed method is therefore especially beneficial for the 3D EDX investigation of electron beam-sensitive materials and studies of nanoparticle transformations. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000671395800001 | Publication Date | 2021-07-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 11 | Open Access | OpenAccess |
Notes | Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 016.Veni.192.235 ; H2020 European Research Council, 815128 ; H2020 Marie Skłodowska-Curie Actions, 797153 ; H2020 Research Infrastructures, 731019; realnano; sygmaSB | Approved | Most recent IF: 7.367 | ||
Call Number | EMAT @ emat @c:irua:179756 | Serial | 6799 | ||
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Author | Shaw, P.; Kumar, N.; Mumtaz, S.; Lim, J.S.; Jang, J.H.; Kim, D.; Sahu, B.D.; Bogaerts, A.; Choi, E.H. | ||||
Title | Evaluation of non-thermal effect of microwave radiation and its mode of action in bacterial cell inactivation | Type | A1 Journal Article | ||
Year | 2021 | Publication | Scientific Reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 11 | Issue | 1 | Pages | 14003 |
Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | A growing body of literature has recognized the non-thermal effect of pulsed microwave radiation (PMR) on bacterial systems. However, its mode of action in deactivating bacteria has not yet been extensively investigated. Nevertheless, it is highly important to advance the applications of PMR from simple to complex biological systems. In this study, we first optimized the conditions of the PMR device and we assessed the results by simulations, using ANSYS HFSS (High Frequency Structure Simulator) and a 3D particle-in-cell code for the electron behavior, to provide a better overview of the bacterial cell exposure to microwave radiation. To determine the sensitivity of PMR,<italic>Escherichia coli</italic> and<italic>Staphylococcus aureus</italic>cultures were exposed to PMR (pulse duration: 60 ns, peak frequency: 3.5 GHz) with power density of 17 kW/cm<sup>2</sup>at the free space of sample position, which would induce electric field of 8.0 kV/cm inside the PBS solution of falcon tube in this experiment at 25 °C. At various discharges (D) of microwaves, the colony forming unit curves were analyzed. The highest ratios of viable count reductions were observed when the doses were increased from 20D to 80D, which resulted in an approximate 6 log reduction in <italic>E. coli</italic>and 4 log reduction in<italic>S. aureus.</italic>Moreover, scanning electron microscopy also revealed surface damage in both bacterial strains after PMR exposure. The bacterial inactivation was attributed to the deactivation of oxidation-regulating genes and DNA damage. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000674547300011 | Publication Date | 2021-07-07 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | Open Access | OpenAccess | |
Notes | Department of Biotechnology, Ministry of Science and Technology, India, D.O.NO.BT/HRD/35/02/2006 ; National Research Foundation of Korea, NRF-2016K1A4A3914113 ; This research was supported by the National Research Foundation (NRF) of Korea, funded by the Korean government (MSIT) under the Grant Number NRF-2016K1A4A3914113, and in part by Kwangwoon University, Seoul, Korea, 2021. We also gratefully acknowledge the financial support obtained from Department of Biotechnology (DBT) Ramalingaswami Re-entry Fellowship, India, Grant Number D.O.NO.BT/HRD/35/02/2006. | Approved | Most recent IF: 4.259 | ||
Call Number | PLASMANT @ plasmant @c:irua:179844 | Serial | 6800 | ||
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Author | Leinders, G.; Baldinozzi, G.; Ritter, C.; Saniz, R.; Arts, I.; Lamoen, D.; Verwerft, M. | ||||
Title | Charge Localization and Magnetic Correlations in the Refined Structure of U3O7 | Type | A1 Journal article | ||
Year | 2021 | Publication | Inorganic Chemistry | Abbreviated Journal | Inorg Chem |
Volume | 60 | Issue | 14 | Pages | 10550-10564 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Atomic arrangements in the mixed-valence oxide U3O7 are refined from high-resolution neutron scattering data. The crystallographic model describes a long-range structural order in a U60O140 primitive cell (space group P42/n) containing distorted cuboctahedral oxygen clusters. By combining experimental data and electronic structure calculations accounting for spin–orbit interactions, we provide robust evidence of an interplay between charge localization and the magnetic moments carried by the uranium atoms. The calculations predict U3O7 to be a semiconducting solid with a band gap of close to 0.32 eV, and a more pronounced charge-transfer insulator behavior as compared to the well-known Mott insulator UO2. Most uranium ions (56 out of 60) occur in 9-fold and 10-fold coordinated environments, surrounding the oxygen clusters, and have a tetravalent (24 out of 60) or pentavalent (32 out of 60) state. The remaining uranium ions (4 out of 60) are not contiguous to the oxygen cuboctahedra and have a very compact, 8-fold coordinated environment with two short (2 × 1.93(3) Å) “oxo-type” bonds. The higher Hirshfeld charge and the diamagnetic character point to a hexavalent state for these four uranium ions. Hence, the valence state distribution corresponds to 24/60 × U(IV) + 32/60 U(V) + 4/60 U(VI). The tetravalent and pentavalent uranium ions are predicted to carry noncollinear magnetic moments (with amplitudes of 1.6 and 0.8 μB, respectively), resulting in canted ferromagnetic order in characteristic layers within the overall fluorite-related structure. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000675430900049 | Publication Date | 2021-07-19 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | Open Access | OpenAccess | |
Notes | Financial support for this research was partly provided by the Energy Transition Fund of the Belgian FPS Economy (Project SF-CORMOD – Spent Fuel CORrosion MODeling). This work was performed in part using HPC resources from GENCI-IDRIS (Grants 2020-101450 and 2020-101601), and in part by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government-department EWI. GL thanks E. Suard and C. Schreinemachers for assistance during the neutron scattering experiments at the ILL. GB acknowledges V. Petříček for suggestions on using JANA2006. | Approved | Most recent IF: 4.857 | ||
Call Number | EMAT @ emat @c:irua:179907 | Serial | 6801 | ||
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Author | Arenas-Vivo, A.; Rojas, S.; Ocaña, I.; Torres, A.; Liras, M.; Salles, F.; Arenas-Esteban, D.; Bals, S.; Ávila, D.; Horcajada, P. | ||||
Title | Ultrafast reproducible synthesis of a Ag-nanocluster@MOF composite and its superior visible-photocatalytic activity in batch and in continuous flow | Type | A1 Journal article | ||
Year | 2021 | Publication | Journal Of Materials Chemistry A | Abbreviated Journal | J Mater Chem A |
Volume | 9 | Issue | 28 | Pages | 15704-15713 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | The (photo)catalytic properties of metal–organic frameworks (MOFs) can be enhanced by post-synthetic inclusion of metallic species in their porosity. Due to their extraordinarily high surface area and well defined porous structure, MOFs can be used for the stabilization of metal nanoparticles with adjustable size within their porosity. Originally, we present here an optimized ultrafast photoreduction protocol for the<italic>in situ</italic>synthesis of tiny and monodisperse silver nanoclusters (AgNCs) homogeneously supported on a photoactive porous titanium carboxylate MIL-125-NH<sub>2</sub>MOF. The strong metal–framework interaction between –NH<sub>2</sub>and Ag atoms influences the AgNC growth, leading to the surfactant-free efficient catalyst AgNC@MIL-125-NH<sub>2</sub>with improved visible light absorption. The potential use of AgNC@MIL-125-NH<sub>2</sub>was further tested in challenging applications: (i) the photodegradation of the emerging organic contaminants (EOCs) methylene blue (MB-dye) and sulfamethazine (SMT-antibiotic) in water treatment, and (ii) the catalytic hydrogenation of<italic>p</italic>-nitroaniline (4-NA) to<italic>p</italic>-phenylenediamine (PPD) with industrial interest. It is noteworthy that compared with the pristine MIL-125-NH<sub>2</sub>, the composite presents an improved catalytic activity and stability, being able to photodegrade 92% of MB in 60 min and 96% of SMT in 30 min, and transform 100% of 4-NA to PPD in 30 min. Aside from these very good results, this study describes for the first time the use of a MOF in a visible light continuous flow reactor for wastewater treatment. With only 10 mg of AgNC@MIL-125-NH<sub>2</sub>, high SMT removal efficiency over 70% is maintained after >2 h under water flow conditions found in real wastewater treatment plants, signaling a future real application of MOFs in water remediation. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000671839200001 | Publication Date | 2021-06-21 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2050-7488 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.867 | Times cited | 18 | Open Access | OpenAccess |
Notes | Comunidad de Madrid, CAM PEJD-2016/IND-2828 Talento Modality 2, 2017-T2/IND-5149 ; Secretaría de Estado de Investigación, Desarrollo e Innovación, Raphuel project (ENE2016-79608-C2-1-R) Retos Project MAT2017-84385-R ; Ministerio de Ciencia e Innovación, Juan de la Cierva Incorporación Fellowship (grant agreement no. IJC2019-038894-I) MOFSEIDON project (PID2019-104228RB-I00) Ramón y Cajal, Grant Agreements 2014-15039 and 2015-18677 ; Fundación BBVA, IN[17]CBBQUI_0197 ; H2020 European Research Council, ERC Consolidator Grant REALNANO 815128 Grant Agreement no. 731019 (EUSMI) ; sygmaSB; | Approved | Most recent IF: 8.867 | ||
Call Number | EMAT @ emat @c:irua:179791 | Serial | 6802 | ||
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Author | Boschker, H.T.S.; Cook, P.L.M.; Polerecky, L.; Eachambadi, R.T.; Lozano, H.; Hidalgo-Martinez, S.; Khalenkow, D.; Spampinato, V.; Claes, N.; Kundu, P.; Wang, D.; Bals, S.; Sand, K.K.; Cavezza, F.; Hauffman, T.; Bjerg, J.T.; Skirtach, A.G.; Kochan, K.; McKee, M.; Wood, B.; Bedolla, D.; Gianoncelli, A.; Geerlings, N.M.J.; Van Gerven, N.; Remaut, H.; Geelhoed, J.S.; Millan-Solsona, R.; Fumagalli, L.; Nielsen, L.P.; Franquet, A.; Manca, J.V.; Gomila, G.; Meysman, F.J.R. | ||||
Title | Efficient long-range conduction in cable bacteria through nickel protein wires | Type | A1 Journal article | ||
Year | 2021 | Publication | Nature Communications | Abbreviated Journal | Nat Commun |
Volume | 12 | Issue | 1 | Pages | 3996 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Filamentous cable bacteria display long-range electron transport, generating electrical currents over centimeter distances through a highly ordered network of fibers embedded in their cell envelope. The conductivity of these periplasmic wires is exceptionally high for a biological material, but their chemical structure and underlying electron transport mechanism remain unresolved. Here, we combine high-resolution microscopy, spectroscopy, and chemical imaging on individual cable bacterium filaments to demonstrate that the periplasmic wires consist of a conductive protein core surrounded by an insulating protein shell layer. The core proteins contain a sulfur-ligated nickel cofactor, and conductivity decreases when nickel is oxidized or selectively removed. The involvement of nickel as the active metal in biological conduction is remarkable, and suggests a hitherto unknown form of electron transport that enables efficient conduction in centimeter-long protein structures. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000669944900006 | Publication Date | 2021-06-28 | |
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ISSN | 2041-1723 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.124 | Times cited | 23 | Open Access | OpenAccess |
Notes | The authors thank Marlies Neiemeisland for assistance with Raman microscopy, Michiel Kienhuis for assistance with NanoSIMS analysis, Peter Hildebrandt and Diego Millo for helping with the interpretation of the Raman spectra, IONTOF for the Orbitrap Hybrid- SIMS analysis, and Rene Fabregas for helping with finite-element numerical modeling for SDM. H.T.S.B. and F.J.R.M. were financially supported by the Netherlands Organization for Scientific Research (VICI grant 016.VICI.170.072). Research Foundation Flanders supported F.J.R.M., J.V.M., and R.T.E. through FWO grant G031416N, and F.J.R.M. and J.S.G. through FWO grant G038819N. N.M.J.G. is the recipient of a Ph.D. scholarship for teachers from NWO in the Netherlands (grant 023.005.049). The NanoSIMS facility at Utrecht University was financed through a large infrastructure grant by the Netherlands Organization for Scientific Research (NWO, grant no. 175.010.2009.011) and through a Research Infrastructure Fund by the Utrecht University Board. A.G.S. is supported by the Special Research Fund (BOF) of Ghent University (BOF14/IOP/003, BAS094-18, 01IO3618) and FWO (G043219). The ToF-SIMS was funded by FWO Hercules grant (ZW/13/07) to J.V.M. and A.F. H.L., R.M.S., and G.G. were funded by the European Union H2020 Framework Programme (MSCA-ITN-2016) under grant agreement n 721874.EU, the Spanish Agencia Estatal de Investigación and EU FEDER under grant agreements TEC2016-79156-P and TEC2015-72751-EXP, the Generalitat de Catalunya through 2017-SGR1079 grant and CERCA Program. G.G. was recipient of an ICREA Academia Award, and H.L. of a FPI fellowship (BES-2015-074799) from the Agencia Estatal de Investigación/Fondo Social Europeo. L.F. received funding from the European Research Council (grant agreement No. 819417) under the European Union’s Horizon 2020 research and innovation programme. | Approved | Most recent IF: 12.124 | ||
Call Number | EMAT @ emat @c:irua:179813 | Serial | 6803 | ||
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Author | Mychinko, M.; Skorikov, A.; Albrecht, W.; Sánchez‐Iglesias, A.; Zhuo, X.; Kumar, V.; Liz‐Marzán, L.M.; Bals, S. | ||||
Title | The Influence of Size, Shape, and Twin Boundaries on Heat‐Induced Alloying in Individual Au@Ag Core–Shell Nanoparticles | Type | A1 Journal article | ||
Year | 2021 | Publication | Small | Abbreviated Journal | Small |
Volume | Issue | Pages | 2102348 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Environmental conditions during real-world application of bimetallic core–shell nanoparticles (NPs) often include the use of elevated temperatures, which are known to cause elemental redistribution, in turn significantly altering the properties of these nanomaterials. Therefore, a thorough understanding of such processes is of great importance. The recently developed combination of fast electron tomography with in situ heating holders is a powerful approach to investigate heat-induced processes at the single NP level, with high spatial resolution in 3D. In combination with 3D finite-difference diffusion simulations, this method can be used to disclose the influence of various NP parameters on the diffusion dynamics in Au@Ag core–shell systems. A detailed study of the influence of heating on atomic diffusion and alloying for Au@Ag NPs with varying core morphology and crystallographic details is carried out. Whereas the core shape and aspect ratio of the NPs play a minor role, twin boundaries are found to have a strong influence on the elemental diffusion. | ||||
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Language | Wos | 000673326600001 | Publication Date | 2021-07-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1613-6810 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.643 | Times cited | 8 | Open Access | OpenAccess |
Notes | The funding for this project was provided by European Research Council (ERC Consolidator Grant 815128, REALNANO) and European Commission (grant 731019, EUSMI and grant 26019, ESTEEM). This work was performed under the Maria de Maeztu Units of Excellence Programme-Grant No. MDM-2017-0720, Ministry of Science and Innovation.; sygmaSB | Approved | Most recent IF: 8.643 | ||
Call Number | EMAT @ emat @c:irua:179856 | Serial | 6804 | ||
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Author | Albrecht, W.; Arslan Irmak, E.; Altantzis, T.; Pedrazo‐Tardajos, A.; Skorikov, A.; Deng, T.‐S.; van der Hoeven, J.E.S.; van Blaaderen, A.; Van Aert, S.; Bals, S. | ||||
Title | 3D Atomic‐Scale Dynamics of Laser‐Light‐Induced Restructuring of Nanoparticles Unraveled by Electron Tomography | Type | A1 Journal article | ||
Year | 2021 | Publication | Advanced Materials | Abbreviated Journal | Adv Mater |
Volume | Issue | Pages | 2100972 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Understanding light–matter interactions in nanomaterials is crucial for optoelectronic, photonic, and plasmonic applications. Specifically, metal nanoparticles (NPs) strongly interact with light and can undergo shape transformations, fragmentation and ablation upon (pulsed) laser excitation. Despite being vital for technological applications, experimental insight into the underlying atomistic processes is still lacking due to the complexity of such measurements. Herein, atomic resolution electron tomography is performed on the same mesoporous-silica-coated gold nanorod, before and after femtosecond laser irradiation, to assess the missing information. Combined with molecular dynamics (MD) simulations based on the experimentally determined 3D atomic-scale morphology, the complex atomistic rearrangements, causing shape deformations and defect generation, are unraveled. These rearrangements are simultaneously driven by surface diffusion, facet restructuring, and strain formation, and are influenced by subtleties in the atomic distribution at the surface. |
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Language | Wos | 000671662000001 | Publication Date | 2021-07-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0935-9648 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 19.791 | Times cited | 8 | Open Access | OpenAccess |
Notes | W.A. and E.A.I. contributed equally to this work. The authors acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128 – REALNANO and No. 770887 – PICOMETRICS), the European Union’s Seventh Framework Programme (ERC Advanced Grant No. 291667 – HierarSACol), and the European Commission (EUSMI). W.A. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in the Horizon2020 program (Grant 797153, SOPMEN). T.-S.D. acknowledges financial support from the National Science Foundation of China (NSFC, Grant No. 61905056). The authors also acknowledge financial support by the Research Foundation Flanders (FWO Grant G.0267.18N).; sygmaSB | Approved | Most recent IF: 19.791 | ||
Call Number | EMAT @ emat @c:irua:179781 | Serial | 6805 | ||
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Author | Oliveira, M.C.; Yusupov, M.; Cordeiro, R.M.; Bogaerts, A. | ||||
Title | Unraveling the permeation of reactive species across nitrated membranes by computer simulations | Type | A1 Journal Article;Reactive oxygen and nitrogen species | ||
Year | 2021 | Publication | Computers In Biology And Medicine | Abbreviated Journal | Comput Biol Med |
Volume | 136 | Issue | Pages | 104768 | |
Keywords | A1 Journal Article;Reactive oxygen and nitrogen species; Nitro-oxidative stress; Molecular dynamics simulations; Nitrated membranes; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | Reactive oxygen and nitrogen species (RONS) are involved in many biochemical processes, including nitrooxidative stress that causes cancer cell death, observed in cancer therapies such as photodynamic therapy and cold atmospheric plasma. However, their mechanisms of action and selectivity still remain elusive due to the complexity of biological cells. For example, it is not well known how RONS generated by cancer therapies permeate the cell membrane to cause nitro-oxidative damage. There are many studies dedicated to the permeation of RONS across native and oxidized membranes, but not across nitrated membranes, another lipid product also generated during nitro-oxidative stress. Herein, we performed molecular dynamics (MD) simulations to calculate the free energy barrier of RONS permeation across nitrated membranes. Our results show that hydrophilic RONS, such as hydroperoxyl radical (HO2) and peroxynitrous acid (ONOOH), have relatively low barriers compared to hydrogen peroxide (H2O2) and hydroxyl radical (HO), and are more prone to permeate the membrane than for the native or peroxidized membranes, and similar to aldehyde-oxidized membranes. Hydrophobic RONS like molecular oxygen (O2), nitrogen dioxide (NO2) and nitric oxide (NO) even have insignificant barriers for permeation. Compared to native and peroxidized membranes, nitrated membranes are more permeable, suggesting that we must not only consider oxidized membranes during nitro-oxidative stress, but also nitrated membranes, and their role in cancer therapies. | ||||
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Language | Wos | 000696938800003 | Publication Date | 2021-08-17 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0010-4825 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.836 | Times cited | Open Access | OpenAccess | |
Notes | We thank University of Antwerp and Coordination of Superior Level Staff Improvement (CAPES, Brazil) for the scholarship granted and for providing the computational resources needed for completion of this work. M. Yusupov acknowledges the Flanders Research Foundation (grant 1200219N) for financial support. | Approved | Most recent IF: 1.836 | ||
Call Number | PLASMANT @ plasmant @c:irua:181082 | Serial | 6807 | ||
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Author | Bal, K.M.; Neyts, E.C. | ||||
Title | Quantifying the impact of vibrational nonequilibrium in plasma catalysis: insights from a molecular dynamics model of dissociative chemisorption | Type | A1 Journal Article;plasma catalysis | ||
Year | 2021 | Publication | Journal Of Physics D-Applied Physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 54 | Issue | 39 | Pages | 394004 |
Keywords | A1 Journal Article;plasma catalysis; vibrational nonequilibrium; dissociative chemisorption; free energy barriers; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | The rate, selectivity and efficiency of plasma-based conversion processes is strongly affected by nonequilibrium phenomena. High concentrations of vibrationally excited molecules are such a plasma-induced effect. It is frequently assumed that vibrationally excited molecules are important in plasma catalysis because their presence lowers the apparent activation energy of dissociative chemisorption reactions and thus increases the conversion rate. A detailed atomic-level understanding of vibrationally stimulated catalytic reactions in the context of plasma catalysis is however lacking. Here, we couple a recently developed statistical model of a plasma-induced vibrational nonequilibrium to molecular dynamics simulations, enhanced sampling methods, and machine learning techniques. We quantify the impact of a vibrational nonequilibrium on the dissociative chemisorption barrier of H2 and CH4 on nickel catalysts over a wide range of vibrational temperatures. We investigate the effect of surface structure and compare the role of different vibrational modes of methane in the dissociation process. For low vibrational temperatures, very high vibrational efficacies are found, and energy in bend vibrations appears to dominate the dissociation of methane. The relative impact of vibrational nonequilibrium is much higher on terrace sites than on surface steps. We then show how our simulations can help to interpret recent experimental results, and suggest new paths to a better understanding of plasma catalysis. | ||||
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Language | Wos | 000674464100001 | Publication Date | 2021-09-30 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0022-3727 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.588 | Times cited | Open Access | OpenAccess | |
Notes | Fonds Wetenschappelijk Onderzoek, 12ZI420N ; K M B was funded as a junior postdoctoral fellow of the FWO (Research Foundation—Flanders), Grant 12ZI420N. The computational resources and services used in this work were provided by the HPC core facility CalcUA of the Universiteit Antwerpen, and VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government. HLDA calculations were performed with a script provided by G Piccini. | Approved | Most recent IF: 2.588 | ||
Call Number | PLASMANT @ plasmant @c:irua:179830 | Serial | 6808 | ||
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Author | Pietanza, L.D.; Guaitella, O.; Aquilanti, V.; Armenise, I.; Bogaerts, A.; Capitelli, M.; Colonna, G.; Guerra, V.; Engeln, R.; Kustova, E.; Lombardi, A.; Palazzetti, F.; Silva, T. | ||||
Title | Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review | Type | A1 Journal Article | ||
Year | 2021 | Publication | European Physical Journal D | Abbreviated Journal | Eur Phys J D |
Volume | 75 | Issue | 9 | Pages | 237 |
Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | Numerous applications have required the study of CO2 plasmas since the 1960s, from CO2 lasers to spacecraft heat shields. However, in recent years, intense research activities on the subject have restarted because of environmental problems associated with CO2 emissions. The present review provides a synthesis of the current state of knowledge on the physical chemistry of cold CO2 plasmas. In particular, the different modeling approaches implemented to address specific aspects of CO2 plasmas are presented. Throughout the paper, the importance of conducting joint experimental, theoretical and modeling studies to elucidate the complex couplings at play in CO2 plasmas is emphasized. Therefore, the experimental data that are likely to bring relevant constraints to the different modeling approaches are first reviewed. Second, the calculation of some key elementary processes obtained with semi-empirical, classical and quantum methods is presented. In order to describe the electron kinetics, the latest coherent sets of cross section satisfying the constraints of “electron swarm” analyses are introduced, and the need for self-consistent calculations for determining accurate electron energy distribution function (EEDF) is evidenced. The main findings of the latest zero-dimensional (0D) global models about the complex chemistry of CO2 and its dissociation products in different plasma discharges are then given, and full state-to-state (STS) models of only the vibrational-dissociation kinetics developed for studies of spacecraft shields are described. Finally, two important points for all applications using CO2 containing plasma are discussed: the role of surfaces in contact with the plasma, and the need for 2D/3D models to capture the main features of complex reactor geometries including effects induced by fluid dynamics on the plasma properties. In addition to bringing together the latest advances in the description of CO2 non-equilibrium plasmas, the results presented here also highlight the fundamental data that are still missing and the possible routes that still need to be investigated. | ||||
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Language | Wos | 000692394800001 | Publication Date | 2021-09-01 | |
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ISSN | 1434-6060 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.288 | Times cited | Open Access | OpenAccess | |
Notes | Russian Science Foundation, project 19-11-00041 ; Marie Skłodowska-Curie Actions, grant agreement 813393 grant agreement 813393 ; H2020 Marie Skłodowska-Curie Actions, grant agreement 813393 grant agreement 813393 ; Fundação para a Ciência e a Tecnologia, UIDB/50010/2020 and UIDP/50010/2020 UIDB/50010/2020 and UIDP/50010/2020 ; Università degli Studi di Perugia, AMIS project (Dipartimenti di Eccellenza-2018-2022) Dipartimento di Chimica, Biologia e Biotecnologie (Fondo Ricerca di Base 2019 program)) ; agenzia spaziale italiana, ASI N. 2019-3-U.0 ; The work of Kustova is supported by the Russian Science Foundation, project 19-11-00041. The work of Guerra, Bogaerts, Engeln and Guaitella has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie SklodowskaCurie grant agreement No 813393, Guerra and Silva were partially funded by the Portuguese FCT – Fundação para | Approved | Most recent IF: 1.288 | ||
Call Number | PLASMANT @ plasmant @c:irua:181081 | Serial | 6809 | ||
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Author | De wael, A.; De Backer, A.; Lobato, I.; Van Aert, S. | ||||
Title | Modelling ADF STEM images using elliptical Gaussian peaks and its effects on the quantification of structure parameters in the presence of sample tilt | Type | A1 Journal article | ||
Year | 2021 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | Issue | Pages | 113391 | ||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A small sample tilt away from a main zone axis orientation results in an elongation of the atomic columns in ADF STEM images. An often posed research question is therefore whether the ADF STEM image intensities of tilted nanomaterials should be quantified using a parametric imaging model consisting of elliptical rather than the currently used symmetrical peaks. To this purpose, simulated ADF STEM images corresponding to different amounts of sample tilt are studied using a parametric imaging model that consists of superimposed 2D elliptical Gaussian peaks on the one hand and symmetrical Gaussian peaks on the other hand. We investigate the quantification of structural parameters such as atomic column positions and scattering cross sections using both parametric imaging models. In this manner, we quantitatively study what can be gained from this elliptical model for quantitative ADF STEM, despite the increased parameter space and computational effort. Although a qualitative improvement can be achieved, no significant quantitative improvement in the estimated structure parameters is achieved by the elliptical model as compared to the symmetrical model. The decrease in scattering cross sections with increasing sample tilt is even identical for both types of parametric imaging models. This impedes direct comparison with zone axis image simulations. Nonetheless, we demonstrate how reliable atom-counting can still be achieved in the presence of small sample tilt. | ||||
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Language | Wos | 000704334200001 | Publication Date | 2021-09-24 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.843 | Times cited | Open Access | OpenAccess | |
Notes | This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp.; esteem3JRA; esteem3reported | Approved | Most recent IF: 2.843 | ||
Call Number | EMAT @ emat @c:irua:181462 | Serial | 6810 | ||
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Author | Engelmann, Y.; van ’t Veer, K.; Gorbanev, Y.; Neyts, E.C.; Schneider, W.F.; Bogaerts, A. | ||||
Title | Plasma Catalysis for Ammonia Synthesis: A Microkinetic Modeling Study on the Contributions of Eley–Rideal Reactions | Type | A1 Journal Article;Plasma catalysis | ||
Year | 2021 | Publication | Acs Sustainable Chemistry & Engineering | Abbreviated Journal | Acs Sustain Chem Eng |
Volume | 9 | Issue | 39 | Pages | 13151-13163 |
Keywords | A1 Journal Article;Plasma catalysis; Eley−Rideal reactions; Volcano plots; Vibrational excitation; Radical reactions; Dielectric barrier discharge; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | Plasma catalysis is an emerging new technology for the electrification and downscaling of NH3 synthesis. Increasing attention is being paid to the optimization of plasma catalysis with respect to the plasma conditions, the catalyst material, and their mutual interaction. In this work we use microkinetic models to study how the total conversion process is impacted by the combination of different plasma conditions and transition metal catalysts. We study how plasma-generated radicals and vibrationally excited N2 (present in a dielectric barrier discharge plasma) interact with the catalyst and impact the NH3 turnover frequencies (TOFs). Both filamentary and uniform plasmas are studied, based on plasma chemistry models that provided plasma phase speciation and vibrational distribution functions. The Langmuir−Hinshelwood reaction rate coefficients (i.e., adsorption reactions and subsequent reactions among adsorbates) are determined using conventional scaling relations. An additional set of Eley−Rideal reactions (i.e., direct reactions of plasma radicals with adsorbates) was added and a sensitivity analysis on the assumed reaction rate coefficients was performed. We first show the impact of different vibrational distribution functions on the catalytic dissociation of N2 and subsequent production of NH3, and we gradually include more radical reactions, to illustrate the contribution of these species and their corresponding reaction pathways. Analysis over a large range of catalysts indicates that different transition metals (metals such as Rh, Ni, Pt, and Pd) optimize the NH3TOFs depending on the population of the vibrational levels of N2. At higher concentrations of plasma-generated radicals, the NH3 TOFs become less dependent on the catalyst material, due to radical adsorptions on the more noble catalysts and Eley−Rideal reactions on the less noble catalysts. | ||||
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Language | Wos | 000705367800004 | Publication Date | 2021-10-04 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 2168-0485 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 5.951 | Times cited | Open Access | OpenAccess | |
Notes | Basic Energy Sciences, DE-SC0021107 ; Vlaamse regering, HBC.2019.0108 ; H2020 European Research Council, 810182 ; Methusalem project – University of Antwerp; Excellence of science FWO-FNRS, GoF9618n ; TOP-BOF – University of Antwerp; DOCPRO3 – University of Antwerp; We acknowledge the financial support from the DOC-PRO3, the TOP-BOF, and the Methusalem project of the University of Antwerp, as well as from the European Research Council (ERC) (grant agreement No, 810182−SCOPE ERC Synergy project), under the European Union’s Horizon 2020 research and innovation programme, the Flemish Government through the Moonshot cSBO project P2C (HBC.2019.0108), and the Excellence of Science FWO-FNRS project (FWO grant ID GoF9618n, EOS ID 30505023). Calculations were carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (Department EWI), 13162 | Approved | Most recent IF: 5.951 | ||
Call Number | PLASMANT @ plasmant @c:irua:182482 | Serial | 6811 | ||
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Author | Dingenen, F.; Blommaerts, N.; Van Hal, M.; Borah, R.; Arenas-Esteban, D.; Lenaerts, S.; Bals, S.; Verbruggen, S.W. | ||||
Title | Layer-by-Layer-Stabilized Plasmonic Gold-Silver Nanoparticles on TiO2: Towards Stable Solar Active Photocatalysts | Type | A1 Journal article | ||
Year | 2021 | Publication | Nanomaterials | Abbreviated Journal | Nanomaterials-Basel |
Volume | 11 | Issue | 10 | Pages | 2624 |
Keywords | A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) | ||||
Abstract | To broaden the activity window of TiO2, a broadband plasmonic photocatalyst has been designed and optimized. This plasmonic ‘rainbow’ photocatalyst consists of TiO2 modified with gold–silver composite nanoparticles of various sizes and compositions, thus inducing a broadband interaction with polychromatic solar light. However, these nanoparticles are inherently unstable, especially due to the use of silver. Hence, in this study the application of the layer-by-layer technique is introduced to create a protective polymer shell around the metal cores with a very high degree of control. Various TiO2 species (pure anatase, PC500, and P25) were loaded with different plasmonic metal loadings (0–2 wt %) in order to identify the most solar active composite materials. The prepared plasmonic photocatalysts were tested towards stearic acid degradation under simulated sunlight. From all materials tested, P25 + 2 wt % of plasmonic ‘rainbow’ nanoparticles proved to be the most promising (56% more efficient compared to pristine P25) and was also identified as the most cost-effective. Further, 2 wt % of layer-by-layer-stabilized ‘rainbow’ nanoparticles were loaded on P25. These layer-by-layer-stabilized metals showed superior stability under a heated oxidative atmosphere, as well as in a salt solution. Finally, the activity of the composite was almost completely retained after 1 month of aging, while the nonstabilized equivalent lost 34% of its initial activity. This work shows for the first time the synergetic application of a plasmonic ‘rainbow’ concept and the layer-by-layer stabilization technique, resulting in a promising solar active, and long-term stable photocatalyst. | ||||
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Language | Wos | 000712759800001 | Publication Date | 2021-10-06 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 2079-4991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.553 | Times cited | 7 | Open Access | OpenAccess |
Notes | Research was funded by Research Foundation—Flanders (FWO), FN 700300001— Aspirant F. Dingenen. | Approved | Most recent IF: 3.553 | ||
Call Number | EMAT @ emat @c:irua:183281 | Serial | 6812 | ||
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Author | Esteban, D.A.; Vanrompay, H.; Skorikov, A.; Béché, A.; Verbeeck, J.; Freitag, B.; Bals, S. | ||||
Title | Fast electron low dose tomography for beam sensitive materials | Type | A1 Journal article | ||
Year | 2021 | Publication | Microscopy And Microanalysis | Abbreviated Journal | Microsc Microanal |
Volume | 27 | Issue | S1 | Pages | 2116-2118 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | Publication Date | 2021-07-30 | ||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1431-9276 | ISBN | Additional Links | UA library record | |
Impact Factor | 1.891 | Times cited | Open Access | OpenAccess | |
Notes | Approved | Most recent IF: 1.891 | |||
Call Number | EMAT @ emat @c:irua:183278 | Serial | 6813 | ||
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Author | Vanraes, P.; Parayil Venugopalan, S.; Bogaerts, A. | ||||
Title | Multiscale modeling of plasma–surface interaction—General picture and a case study of Si and SiO2etching by fluorocarbon-based plasmas | Type | A1 Journal Article | ||
Year | 2021 | Publication | Applied Physics Reviews | Abbreviated Journal | Appl Phys Rev |
Volume | 8 | Issue | 4 | Pages | 041305 |
Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | The physics and chemistry of plasma–surface interaction is a broad domain relevant to various applications and several natural processes, including plasma etching for microelectronics fabrication, plasma deposition, surface functionalization, nanomaterial synthesis, fusion reactors, and some astrophysical and meteorological phenomena. Due to their complex nature, each of these processes is generally investigated in separate subdomains, which are considered to have their own theoretical, modeling, and experimental challenges. In this review, however, we want to emphasize the overarching nature of plasma–surface interaction physics and chemistry, by focusing on the general strategy for its computational simulation. In the first half of the review, we provide a menu card with standard and less standardized computational methods to be used for the multiscale modeling of the underlying processes. In the second half, we illustrate the benefits and potential of the multiscale modeling strategy with a case study of Si and SiO2 etching by fluorocarbon plasmas and identify the gaps in knowledge still present on this intensely investigated plasma–material combination, both on a qualitative and quantitative level. Remarkably, the dominant etching mechanisms remain the least understood. The resulting new insights are of general relevance, for all plasmas and materials, including their various applications. We therefore hope to motivate computational and experimental scientists and engineers to collaborate more intensely on filling the existing gaps in knowledge. In this way, we expect that research will overcome a bottleneck stage in the development and optimization of multiscale models, and thus the fundamental understanding of plasma–surface interaction. | ||||
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Language | Wos | 000754799700001 | Publication Date | 2021-10-07 | |
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ISSN | 1931-9401 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 13.667 | Times cited | Open Access | OpenAccess | |
Notes | Asml; P. Vanraes acknowledges funding by ASML for the project “Computational simulation of plasma etching of trench structures.” P. Vanraes wishes to thank Violeta Georgieva and Stefan Tinck for the fruitful discussions on the HPEM code, Yu-Ru Zhang for an example of the CCP reactor code, and Karel Venken for his technical help with the server maintenance and use. P. Vanraes and A. Bogaerts want to express their gratitude to Mark J. Kushner (University of Michigan) for the sharing of the HPEM and MCFPM codes and for the interesting exchange of views. S. P. Venugopalan wishes to thank Sander Wuister, Coen Verschuren, Michael Kubis, Mohammad Kamali, | Approved | Most recent IF: 13.667 | ||
Call Number | PLASMANT @ plasmant @c:irua:183287 | Serial | 6814 | ||
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Author | Gorbanev, Y.; Engelmann, Y.; van’t Veer, K.; Vlasov, E.; Ndayirinde, C.; Yi, Y.; Bals, S.; Bogaerts, A. | ||||
Title | Al2O3-Supported Transition Metals for Plasma-Catalytic NH3 Synthesis in a DBD Plasma: Metal Activity and Insights into Mechanisms | Type | A1 Journal article | ||
Year | 2021 | Publication | Catalysts | Abbreviated Journal | Catalysts |
Volume | 11 | Issue | 10 | Pages | 1230 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Movement Antwerp (MOVANT) | ||||
Abstract | N2 fixation into NH3 is one of the main processes in the chemical industry. Plasma catalysis is among the environmentally friendly alternatives to the industrial energy-intensive Haber-Bosch process. However, many questions remain open, such as the applicability of the conventional catalytic knowledge to plasma. In this work, we studied the performance of Al2O3-supported Fe, Ru, Co and Cu catalysts in plasma-catalytic NH3 synthesis in a DBD reactor. We investigated the effects of different active metals, and different ratios of the feed gas components, on the concentration and production rate of NH3, and the energy consumption of the plasma system. The results show that the trend of the metal activity (common for thermal catalysis) does not appear in the case of plasma catalysis: here, all metals exhibited similar performance. These findings are in good agreement with our recently published microkinetic model. This highlights the virtual independence of NH3 production on the metal catalyst material, thus validating the model and indicating the potential contribution of radical adsorption and Eley-Rideal reactions to the plasma-catalytic mechanism of NH3 synthesis. | ||||
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Language | Wos | 000715656300001 | Publication Date | 2021-10-13 | |
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ISSN | 2073-4344 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.082 | Times cited | 19 | Open Access | OpenAccess |
Notes | Catalisti, Moonshot P2C ; Research Foundation – Flanders, GoF9618n ; European Research Council, 810182 SCOPE 815128 REALNANO ; sygmaSB | Approved | Most recent IF: 3.082 | ||
Call Number | EMAT @ emat @c:irua:183279 | Serial | 6815 | ||
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Author | Prabhakara, V.; Nuytten, T.; Bender, H.; Vandervorst, W.; Bals, S.; Verbeeck, J. | ||||
Title | Linearized radially polarized light for improved precision in strain measurements using micro-Raman spectroscopy | Type | A1 Journal article | ||
Year | 2021 | Publication | Optics Express | Abbreviated Journal | Opt Express |
Volume | 29 | Issue | 21 | Pages | 34531 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Strain engineering in semiconductor transistor devices has become vital in the semiconductor industry due to the ever-increasing need for performance enhancement at the nanoscale. Raman spectroscopy is a non-invasive measurement technique with high sensitivity to mechanical stress that does not require any special sample preparation procedures in comparison to characterization involving transmission electron microscopy (TEM), making it suitable for inline strain measurement in the semiconductor industry. Indeed, at present, strain measurements using Raman spectroscopy are already routinely carried out in semiconductor devices as it is cost effective, fast and non-destructive. In this paper we explore the usage of linearized radially polarized light as an excitation source, which does provide significantly enhanced accuracy and precision as compared to linearly polarized light for this application. Numerical simulations are done to quantitatively evaluate the electric field intensities that contribute to this enhanced sensitivity. We benchmark the experimental results against TEM diffraction-based techniques like nano-beam diffraction and Bessel diffraction. Differences between both approaches are assigned to strain relaxation due to sample thinning required in TEM setups, demonstrating the benefit of Raman for nondestructive inline testing. | ||||
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Language | Wos | 000708940500144 | Publication Date | 2021-10-11 | |
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ISSN | 1094-4087 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.307 | Times cited | 2 | Open Access | OpenAccess |
Notes | Horizon 2020 Framework Programme, 823717 – ESTEEM3 ; GOA project, “Solarpaint” ; Herculesstichting;; esteem3jra; esteem3reported; | Approved | Most recent IF: 3.307 | ||
Call Number | EMAT @ emat @c:irua:182472 | Serial | 6816 | ||
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Author | Hudry, D.; De Backer, A.; Popescu, R.; Busko, D.; Howard, I.A.; Bals, S.; Zhang, Y.; Pedrazo‐Tardajos, A.; Van Aert, S.; Gerthsen, D.; Altantzis, T.; Richards, B.S. | ||||
Title | Interface Pattern Engineering in Core‐Shell Upconverting Nanocrystals: Shedding Light on Critical Parameters and Consequences for the Photoluminescence Properties | Type | A1 Journal article | ||
Year | 2021 | Publication | Small | Abbreviated Journal | Small |
Volume | Issue | Pages | 2104441 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Advances in controlling energy migration pathways in core-shell lanthanide (Ln)-based hetero-nanocrystals (HNCs) have relied heavily on assumptions about how optically active centers are distributed within individual HNCs. In this article, it is demonstrated that different types of interface patterns can be formed depending on shell growth conditions. Such interface patterns are not only identified but also characterized with spatial resolution ranging from the nanometer- to the atomic-scale. In the most favorable cases, atomic-scale resolved maps of individual particles are obtained. It is also demonstrated that, for the same type of core-shell architecture, the interface pattern can be engineered with thicknesses of just 1 nm up to several tens of nanometers. Total alloying between the core and shell domains is also possible when using ultra-small particles as seeds. Finally, with different types of interface patterns (same architecture and chemical composition of the core and shell domains) it is possible to modify the output color (yellow, red, and green-yellow) or change (improvement or degradation) the absolute upconversion quantum yield. The results presented in this article introduce an important paradigm shift and pave the way toward the emergence of a new generation of core-shell Ln-based HNCs with better control over their atomic-scale organization. | ||||
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Language | Wos | 000710758000001 | Publication Date | 2021-10-25 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 1613-6810 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.643 | Times cited | 17 | Open Access | OpenAccess |
Notes | The authors would like to acknowledge the financial support provided by the Helmholtz Recruitment Initiative Fellowship (B.S.R.) and the Helmholtz Association's Research Field Energy (Materials and Technologies for the Energy Transition program, Topic 1 Photovoltaics and Wind Energy). The authors would like to thank the Karlsruhe Nano Micro Facility (KNMF) for STEM access. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (Grant agreement no. 770887 PICOMETRICS to S.V.A. and Grant agreement no. 815128 REALNANO to S.B.). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Projects no. G.0502.18N, G.0267.18N, and a postdoctoral grant to A.D.B. T.A. acknowledges funding from the University of Antwerp Research fund (BOF). This project had received funding (EUSMI proposal #E181100205) from the European Union's Horizon 2020 Research and Innovation Programme under Grant agreement no 731019 (EUSMI). D.H. would like to thank “CGFigures” for helpful tutorials on 3D graphics with Blender.; sygmaSB | Approved | Most recent IF: 8.643 | ||
Call Number | EMAT @ emat @c:irua:183285 | Serial | 6817 | ||
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Author | Velazco, A.; Béché, A.; Jannis, D.; Verbeeck, J. | ||||
Title | Reducing electron beam damage through alternative STEM scanning strategies, Part I: Experimental findings | Type | A1 Journal article | ||
Year | 2022 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 232 | Issue | Pages | 113398 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The highly energetic electrons in a transmission electron microscope (TEM) can alter or even completely destroy the structure of samples before sufficient information can be obtained. This is especially problematic in the case of zeolites, organic and biological materials. As this effect depends on both the electron beam and the sample and can involve multiple damage pathways, its study remained difficult and is plagued with irreproducibility issues, circumstantial evidence, rumors, and a general lack of solid data. Here we take on the experimental challenge to investigate the role of the STEM scan pattern on the damage behavior of a commercially available zeolite sample with the clear aim to make our observations as reproducible as possible. We make use of a freely programmable scan engine that gives full control over the tempospatial distribution of the electron probe on the sample and we use its flexibility to obtain multiple repeated experiments under identical conditions comparing the difference in beam damage between a conventional raster scan pattern and a newly proposed interleaved scan pattern that provides exactly the same dose and dose rate and visits exactly the same scan points. We observe a significant difference in beam damage for both patterns with up to 11 % reduction in damage (measured from mass loss). These observations demonstrate without doubt that electron dose, dose rate and acceleration voltage are not the only parameters affecting beam damage in (S)TEM experiments and invite the community to rethink beam damage as an unavoidable consequence of applied electron dose. | ||||
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Language | Wos | 000714819200002 | Publication Date | 2021-10-02 | |
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ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.2 | Times cited | 18 | Open Access | OpenAccess |
Notes | A.V., D.J., A.B. and J.V. acknowledge funding from FWO project G093417N (’Compressed sensing enabling low dose imaging in transmission electron microscopy’) and G042920N (’Coincident event detection for advanced spectroscopy in transmission electron microscopy’). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 ESTEEM3. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. J.V. acknowledges funding from GOA project “Solarpaint” of the University of Antwerp.; JRA; reported | Approved | Most recent IF: 2.2 | ||
Call Number | EMAT @ emat @c:irua:183282 | Serial | 6818 | ||
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Author | Arslan Irmak, E.; Liu, P.; Bals, S.; Van Aert, S. | ||||
Title | 3D Atomic Structure of Supported Metallic Nanoparticles Estimated from 2D ADF STEM Images: A Combination of Atom – Counting and a Local Minima Search Algorithm | Type | A1 Journal article | ||
Year | 2021 | Publication | Small methods | Abbreviated Journal | Small Methods |
Volume | Issue | Pages | 2101150 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Determining the three-dimensional (3D) atomic structure of nanoparticles (NPs) is critical to understand their structure-dependent properties. It is hereby important to perform such analyses under conditions relevant for the envisioned application. Here, we investigate the 3D structure of supported Au NPs at high temperature, which is of importance to understand their behavior during catalytic reactions. To overcome limitations related to conventional high-resolution electron tomography at high temperature, 3D characterization of NPs with atomic resolution has been performed by applying atom-counting using atomic resolution annular darkfield scanning transmission electron microscopy (ADF STEM) images followed by structural relaxation. However, at high temperatures, thermal displacements, which affect the ADF STEM intensities, should be taken into account. Moreover, it is very likely that the structure of a NP investigated at elevated temperature deviates from a ground state configuration, which is difficult to determine using purely computational energy minimization approaches. In this paper, we therefore propose an optimized approach using an iterative local minima search algorithm followed by molecular dynamics (MD) structural relaxation of candidate structures associated with each local minimum. In this manner, it becomes possible to investigate the 3D atomic structure of supported NPs, which may deviate from their ground state configuration. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000716511600001 | Publication Date | 2021-11-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2366-9608 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 12 | Open Access | OpenAccess | |
Notes | This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0267.18N, G.0502.18N, G.0346.21N).; sygmaSB; esteem3jra; esteem3reported | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @c:irua:183289 | Serial | 6820 | ||
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Author | Jannis, D.; Müller-Caspary, K.; Béché, A.; Verbeeck, J. | ||||
Title | Coincidence Detection of EELS and EDX Spectral Events in the Electron Microscope | Type | A1 Journal article | ||
Year | 2021 | Publication | Applied Sciences-Basel | Abbreviated Journal | Appl Sci-Basel |
Volume | 11 | Issue | 19 | Pages | 9058 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Recent advances in the development of electron and X-ray detectors have opened up the possibility to detect single events from which its time of arrival can be determined with nanosecond resolution. This allows observing time correlations between electrons and X-rays in the transmission electron microscope. In this work, a novel setup is described which measures individual events using a silicon drift detector and digital pulse processor for the X-rays and a Timepix3 detector for the electrons. This setup enables recording time correlation between both event streams while at the same time preserving the complete conventional electron energy loss (EELS) and energy dispersive X-ray (EDX) signal. We show that the added coincidence information improves the sensitivity for detecting trace elements in a matrix as compared to conventional EELS and EDX. Furthermore, the method allows the determination of the collection efficiencies without the use of a reference sample and can subtract the background signal for EELS and EDX without any prior knowledge of the background shape and without pre-edge fitting region. We discuss limitations in time resolution arising due to specificities of the silicon drift detector and discuss ways to further improve this aspect. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000710160300001 | Publication Date | 2021-09-28 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2076-3417 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.679 | Times cited | 9 | Open Access | OpenAccess |
Notes | Fonds Wetenschappelijk Onderzoek, G042920 ; Horizon 2020 Framework Programme, 101017720 ; Helmholtz-Fonds, VH-NG-1317 ; | Approved | Most recent IF: 1.679 | ||
Call Number | EMAT @ emat @c:irua:183336 | Serial | 6821 | ||
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Author | Lebedev, N.; Stehno, M.; Rana, A.; Reith, P.; Gauquelin, N.; Verbeeck, J.; Hilgenkamp, H.; Brinkman, A.; Aarts, J. | ||||
Title | Gate-tuned anomalous Hall effect driven by Rashba splitting in intermixed LaAlO3/GdTiO3/SrTiO3 | Type | A1 Journal article | ||
Year | 2021 | Publication | Scientific Reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 11 | Issue | 1 | Pages | 10726 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | The Anomalous Hall Effect (AHE) is an important quantity in determining the properties and understanding the behaviour of the two-dimensional electron system forming at the interface of SrTiO<sub>3</sub>-based oxide heterostructures. The occurrence of AHE is often interpreted as a signature of ferromagnetism, but it is becoming more and more clear that also paramagnets may contribute to AHE. We studied the influence of magnetic ions by measuring intermixed LaAlO<sub>3</sub>/GdTiO<sub>3</sub>/SrTiO<sub>3</sub>at temperatures below 10 K. We find that, as function of gate voltage, the system undergoes a Lifshitz transition while at the same time an onset of AHE is observed. However, we do not observe clear signs of ferromagnetism. We argue the AHE to be due to the change in Rashba spin-orbit coupling at the Lifshitz transition and conclude that also paramagnetic moments which are easily polarizable at low temperatures and high magnetic fields lead to the presence of AHE, which needs to be taken into account when extracting carrier densities and mobilities. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000658820100014 | Publication Date | 2021-05-21 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 5 | Open Access | OpenAccess |
Notes | J.V. and N.G. acknowledge funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp and the European Union’s horizon 2020 research and innovation programme ESTEEM3 under grant agreement 823717. The Qu-Ant-EM microscope used in this study was partly funded by the Hercules fund from the Flemish Government.; esteem3TA; esteem3reported | Approved | Most recent IF: 4.259 | ||
Call Number | EMAT @ emat @c:irua:179608 | Serial | 6822 | ||
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Author | Herzog, M.J.; Gauquelin, N.; Esken, D.; Verbeeck, J.; Janek, J. | ||||
Title | Increased Performance Improvement of Lithium-Ion Batteries by Dry Powder Coating of High-Nickel NMC with Nanostructured Fumed Ternary Lithium Metal Oxides | Type | A1 Journal article | ||
Year | 2021 | Publication | ACS applied energy materials | Abbreviated Journal | ACS Appl. Energy Mater. |
Volume | 4 | Issue | 9 | Pages | 8832-8848 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Dry powder coating is an effective approach to protect the surfaces of layered cathode active materials (CAMs) in lithium-ion batteries. Previous investigations indicate an incorporation of lithium ions in fumed Al2O3, ZrO2, and TiO2 coatings on LiNi0.7Mn0.15Co0.15O2 during cycling, improving the cycling performance. Here, this coating approach is transferred for the first time to fumed ternary LiAlO2, Li4Zr3O8, and Li4Ti5O12 and directly compared with their lithium-free equivalents. All materials could be processed equally and their nanostructured small aggregates accumulate on the CAM surfaces to quite homogeneous coating layers with a certain porosity. The LiNixMnyCozO2 (NMC) coated with lithium-containing materials shows an enhanced improvement in overall capacity, capacity retention, rate performance, and polarization behavior during cycling, compared to their lithium-free analogues. The highest rate performance was achieved with the fumed ZrO2 coating, while the best long-term cycling stability with the highest absolute capacity was obtained for the fumed LiAlO2-coated NMC. The optimal coating agent for NMC to achieve a balanced system is fumed Li4Ti5O12, providing a good compromise between high rate capability and good capacity retention. The coating agents prevent CAM particle cracking and degradation in the order LiAlO2 ≈ Al2O3 > Li4Ti5O12 > Li4Zr3O8 > ZrO2 > TiO2. A schematic model for the protection and electrochemical performance enhancement of high-nickel NMC with fumed metal oxide coatings is sketched. It becomes apparent that physical and chemical characteristics of the coating significantly influence the performance of NMC. A high degree of coating-layer porosity is favorable for the rate capability, while a high coverage of the surface, especially in vulnerable grain boundaries, enhances the long-term cycling stability and improves the cracking behavior of NMCs. While zirconium-containing coatings possess the best chemical properties for high rate performances, aluminum-containing coatings feature a superior chemical nature to protect high-nickel NMCs. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000703338600018 | Publication Date | 2021-09-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2574-0962 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 15 | Open Access | OpenAccess | |
Notes | For his support in scanning electron microscopy analysis, the authors thank Erik Peldszus. N. G. and J. V. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and from the Flemish Research Fund (FWO) project G0F1320N. The Qu-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @c:irua:183949 | Serial | 6823 | ||
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Author | van Thiel, T. c.; Brzezicki, W.; Autieri, C.; Hortensius, J. r.; Afanasiev, D.; Gauquelin, N.; Jannis, D.; Janssen, N.; Groenendijk, D. j.; Fatermans, J.; Van Aert, S.; Verbeeck, J.; Cuoco, M.; Caviglia, A. d. | ||||
Title | Coupling Charge and Topological Reconstructions at Polar Oxide Interfaces | Type | A1 Journal article | ||
Year | 2021 | Publication | Physical Review Letters | Abbreviated Journal | Phys Rev Lett |
Volume | 127 | Issue | 12 | Pages | 127202 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In oxide heterostructures, different materials are integrated into a single artificial crystal, resulting in a breaking of inversion symmetry across the heterointerfaces. A notable example is the interface between polar and nonpolar materials, where valence discontinuities lead to otherwise inaccessible charge and spin states. This approach paved the way for the discovery of numerous unconventional properties absent in the bulk constituents. However, control of the geometric structure of the electronic wave functions in correlated oxides remains an open challenge. Here, we create heterostructures consisting of ultrathin SrRuO3, an itinerant ferromagnet hosting momentum-space sources of Berry curvature, and LaAlO3, a polar wide-band-gap insulator. Transmission electron microscopy reveals an atomically sharp LaO/RuO2/SrO interface configuration, leading to excess charge being pinned near the LaAlO3/SrRuO3 interface. We demonstrate through magneto-optical characterization, theoretical calculations and transport measurements that the real-space charge reconstruction drives a reorganization of the topological charges in the band structure, thereby modifying the momentum-space Berry curvature in SrRuO3. Our results illustrate how the topological and magnetic features of oxides can be manipulated by engineering charge discontinuities at oxide interfaces. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000704665000010 | Publication Date | 2021-09-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 17 | Open Access | OpenAccess |
Notes | The authors thank E. Lesne, M. Lee, H. Barakov, M. Matthiesen and U. Filippozzi for discussions. The authors are grateful to E.J.S. van Thiel for producing the illustration in Fig. 4a. This work was supported by the European Research Council under the European Unions Horizon 2020 programme/ERC Grant agreements No. [677458], [770887] and No. [731473] (Quantox of QuantERA ERA-NET Cofund in Quantum Technologies) and by the Netherlands Organisation for Scientific Research (NWO/OCW) as part of the Frontiers of Nanoscience (NanoFront) and VIDI program. The authors acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. [823717] – ESTEEM3. N. G., J. V., and S. V. A. acknowledge funding from the University of Antwerp through the Concerted Research Actions (GOA) project Solarpaint and the TOP project. C. A. and W. B. are supported by the Foundation for Polish Science through the International Research Agendas program co-financed by the European Union within the Smart Growth Operational Programme. C. A. acknowledges access to the computing facilities of the Interdisciplinary Center of Modeling at the University of Warsaw, Grant No. G73-23 and G75-10. W.B. acknowledges support from the Narodowe Centrum Nauk (NCN, National Science Centre, Poland) Project No. 2019/34/E/ST3/00404'; esteem3TA; esteem3reported | Approved | Most recent IF: 8.462 | ||
Call Number | EMAT @ emat @c:irua:182595 | Serial | 6824 | ||
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Author | Koo, J.; Dahl, A.B.; Bærentzen, J.A.; Chen, Q.; Bals, S.; Dahl, V.A. | ||||
Title | Shape from projections via differentiable forward projector for computed tomography | Type | A1 Journal article | ||
Year | 2021 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 224 | Issue | Pages | 113239 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | In computed tomography, the reconstruction is typically obtained on a voxel grid. In this work, however, we propose a mesh-based reconstruction method. For tomographic problems, 3D meshes have mostly been studied to simulate data acquisition, but not for reconstruction, for which a 3D mesh means the inverse process of estimating shapes from projections. In this paper, we propose a differentiable forward model for 3D meshes that bridge the gap between the forward model for 3D surfaces and optimization. We view the forward projection as a rendering process, and make it differentiable by extending recent work in differentiable rendering. We use the proposed forward model to reconstruct 3D shapes directly from projections. Experimental results for single-object problems show that the proposed method outperforms traditional voxel-based methods on noisy simulated data. We also apply the proposed method on electron tomography images of nanoparticles to demonstrate the applicability of the method on real data. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000744576800008 | Publication Date | 2021-03-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.843 | Times cited | 3 | Open Access | OpenAccess |
Notes | EU Horizon 2020 MSCA Innovative Training Network MUMMERING Grant Number 765604. | Approved | Most recent IF: 2.843 | ||
Call Number | EMAT @ emat @c:irua:183267 | Serial | 6825 | ||
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Author | Van Loenhout, J.; Freire Boullosa, L.; Quatannens, D.; De Waele, J.; Merlin, C.; Lambrechts, H.; Lau, H.W.; Hermans, C.; Lin, A.; Lardon, F.; Peeters, M.; Bogaerts, A.; Smits, E.; Deben, C. | ||||
Title | Auranofin and Cold Atmospheric Plasma Synergize to Trigger Distinct Cell Death Mechanisms and Immunogenic Responses in Glioblastoma | Type | A1 Journal Article;oxidative stress | ||
Year | 2021 | Publication | Cells | Abbreviated Journal | Cells |
Volume | 10 | Issue | 11 | Pages | 2936 |
Keywords | A1 Journal Article;oxidative stress; auranofin; cold atmospheric plasma; glioblastoma; cancer cell death; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | Targeting the redox balance of malignant cells via the delivery of high oxidative stress unlocks a potential therapeutic strategy against glioblastoma (GBM). We investigated a novel reactive oxygen species (ROS)-inducing combination treatment strategy, by increasing exogenous ROS via cold atmospheric plasma and inhibiting the endogenous protective antioxidant system via auranofin (AF), a thioredoxin reductase 1 (TrxR) inhibitor. The sequential combination treatment of AF and cold atmospheric plasma-treated PBS (pPBS), or AF and direct plasma application, resulted in a synergistic response in 2D and 3D GBM cell cultures, respectively. Differences in the baseline protein levels related to the antioxidant systems explained the cell-line-dependent sensitivity towards the combination treatment. The highest decrease of TrxR activity and GSH levels was observed after combination treatment of AF and pPBS when compared to AF and pPBS monotherapies. This combination also led to the highest accumulation of intracellular ROS. We confirmed a ROS-mediated response to the combination of AF and pPBS, which was able to induce distinct cell death mechanisms. On the one hand, an increase in caspase-3/7 activity, with an increase in the proportion of annexin V positive cells, indicates the induction of apoptosis in the GBM cells. On the other hand, lipid peroxidation and inhibition of cell death through an iron chelator suggest the involvement of ferroptosis in the GBM cell lines. Both cell death mechanisms induced by the combination of AF and pPBS resulted in a significant increase in danger signals (ecto-calreticulin, ATP and HMGB1) and dendritic cell maturation, indicating a potential increase in immunogenicity, although the phagocytotic capacity of dendritic cells was inhibited by AF. In vivo, sequential combination treatment of AF and cold atmospheric plasma both reduced tumor growth kinetics and prolonged survival in GBM-bearing mice. Thus, our study provides a novel therapeutic strategy for GBM to enhance the efficacy of oxidative stress-inducing therapy through a combination of AF and cold atmospheric plasma. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000807134000001 | Publication Date | 2021-10-28 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2073-4409 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | OpenAccess | ||
Notes | Olivia Hendrickx Research Fund, 21OCL06 ; University of Antwerp, FFB160231 ; The authors would express their gratitude to Hans de Reu for technical assistance with flow cytometry. | Approved | Most recent IF: NA | ||
Call Number | PLASMANT @ plasmant @c:irua:182915 | Serial | 6826 | ||
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Author | Van Alphen, S.; Slaets, J.; Ceulemans, S.; Aghaei, M.; Snyders, R.; Bogaerts, A. | ||||
Title | Effect of N2 on CO2-CH4 conversion in a gliding arc plasmatron: Can this major component in industrial emissions improve the energy efficiency? | Type | A1 Journal Article;Plasma-based CO2-CH4 conversion | ||
Year | 2021 | Publication | Journal Of Co2 Utilization | Abbreviated Journal | J Co2 Util |
Volume | 54 | Issue | Pages | 101767 | |
Keywords | A1 Journal Article;Plasma-based CO2-CH4 conversion; Effect of N2; Plasma chemistry; Computational modelling; Gliding arc plasmatron; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | Plasma-based CO2 and CH4 conversion is gaining increasing interest, and a great portion of research is dedicated to adapting the process to actual industrial conditions. In an industrial context, the process needs to be able to process N2 admixtures, since most industrial gas emissions contain significant amounts of N2, and gas separations are financially costly. In this paper we therefore investigate the effect of N2 on the CO2 and CH4 conversion in a gliding arc plasmatron reactor. The addition of 20 % N2 reduces the energy cost of the conversion process by 21 % compared to a pure CO2/CH4 mixture, from 2.9 down to 2.2 eV/molec (or from 11.5 to 8.7 kJ/L), yielding a CO2 and CH4 (absolute) conversion of 28.6 and 35.9 % and an energy efficiency of 58 %. These results are among the best reported in literature for plasma-based DRM, demonstrating the benefits of N2 present in the mix. Compared to DRM results in different plasma reactor types, a low energy cost was achieved. To understand the underlying mechanisms of N2 addition, we developed a combination of four different computational models, which reveal that the beneficial effect of N2 addition is attributed to (i) a rise in the electron density (increasing the plasma conductivity, and therefore reducing the plasma power needed to sustain the plasma, which reduces the energy cost), as well as (ii) a rise in the gas temperature, which accelerates the CO2 and CH4 conversion reactions. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000715057300005 | Publication Date | 2021-10-28 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2212-9820 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.292 | Times cited | Open Access | OpenAccess | |
Notes | This research was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innova tion programme (grant agreement No 810182 – SCOPE ERC Synergy project), the Excellence of Science FWO-FNRS project (FWO grant ID GoF9618n, EOS ID 30505023), and through long-term structural funding (Methusalem). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. | Approved | Most recent IF: 4.292 | ||
Call Number | PLASMANT @ plasmant @c:irua:184044 | Serial | 6827 | ||
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Author | Jannis, D.; Hofer, C.; Gao, C.; Xie, X.; Béché, A.; Pennycook, Tj.; Verbeeck, J. | ||||
Title | Event driven 4D STEM acquisition with a Timepix3 detector: Microsecond dwell time and faster scans for high precision and low dose applications | Type | A1 Journal article | ||
Year | 2022 | Publication | Ultramicroscopy | Abbreviated Journal | Ultramicroscopy |
Volume | 233 | Issue | Pages | 113423 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Four dimensional scanning transmission electron microscopy (4D STEM) records the scattering of electrons in a material in great detail. The benefits offered by 4D STEM are substantial, with the wealth of data it provides facilitating for instance high precision, high electron dose efficiency phase imaging via centre of mass or ptychography based analysis. However the requirement for a 2D image of the scattering to be recorded at each probe position has long placed a severe bottleneck on the speed at which 4D STEM can be performed. Recent advances in camera technology have greatly reduced this bottleneck, with the detection efficiency of direct electron detectors being especially well suited to the technique. However even the fastest frame driven pixelated detectors still significantly limit the scan speed which can be used in 4D STEM, making the resulting data susceptible to drift and hampering its use for low dose beam sensitive applications. Here we report the development of the use of an event driven Timepix3 direct electron camera that allows us to overcome this bottleneck and achieve 4D STEM dwell times down to 100 ns; orders of magnitude faster than what has been possible with frame based readout. We characterize the detector for different acceleration voltages and show that the method is especially well suited for low dose imaging and promises rich datasets without compromising dwell time when compared to conventional STEM imaging. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000734396800003 | Publication Date | 2021-11-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0304-3991 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.2 | Times cited | 31 | Open Access | OpenAccess |
Notes | This project has received funding from the Euro- pean Union’s Horizon 2020 Research Infrastructure – Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3. J.V. and A.B. acknowledge funding from FWO project G093417N (‘Compressed sensing enabling low dose imaging in transmission electron microscopy’). J.V. and D.J. ac- knowledge funding from FWO project G042920N ‘Co- incident event detection for advanced spectroscopy in transmission electron microscopy’. We acknowledge funding under the European Union’s Horizon 2020 re- search and innovation programme (J.V. and D.J un- der grant agreement No 101017720, FET-Proactive EBEAM, and C.H., C.G., X.X. and T.J.P. from the Eu- ropean Research Council (ERC) Grant agreement No. 802123-HDEM).; esteem3JRA; esteem3reported | Approved | Most recent IF: 2.2 | ||
Call Number | EMAT @ emat @c:irua:183948 | Serial | 6828 | ||
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Author | Walters, A.A.; Santacana-Font, G.; Li, J.; Routabi, N.; Qin, Y.; Claes, N.; Bals, S.; Tzu-Wen Wang, J.; Al-Jamal, K.T. | ||||
Title | Nanoparticle-MediatedIn SituMolecular Reprogramming of Immune Checkpoint Interactions for Cancer Immunotherapy | Type | A1 Journal article | ||
Year | 2021 | Publication | Acs Nano | Abbreviated Journal | Acs Nano |
Volume | 15 | Issue | 11 | Pages | 17549-17564 |
Keywords | A1 Journal article; Pharmacology. Therapy; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Immune checkpoint blockade involves targeting immune regulatory molecules with antibodies. Preclinically, complex multiantibody regimes of both inhibitory and stimulatory targets are a promising candidate for the next generation of immunotherapy. However, in this setting, the antibody platform may be limited due to excessive toxicity caused by off target effects as a result of systemic administration. RNA can be used as an alternate to antibodies as it can both downregulate immunosuppressive checkpoints (siRNA) or induce expression of immunostimulatory checkpoints (mRNA). In this study, we demonstrate that the combination of both siRNA and mRNA in a single formulation can simultaneously knockdown and induce expression of immune checkpoint targets, thereby reprogramming the tumor microenvironment from immunosuppressive to immunostimulatory phenotype. To achieve this, RNA constructs were synthesized and formulated into stable nucleic acid lipid nanoparticles (SNALPs); the SNALPs produced were 140−150 nm in size with >80% loading efficiency. SNALPs could transfect macrophages and B16F10 cells in vitro resulting in 75% knockdown of inhibitory checkpoint (PDL1) expression and simultaneously express high levels of stimulatory checkpoint (OX40L) with minimal toxicity. Intratumoral treatment with the proposed formulation resulted in statistically reduced tumor growth, a greater density of CD4+ and CD8+ infiltrates in the tumor, and immune activation within tumor-draining lymph nodes. These data suggest that a single RNA-based formulation can successfully reprogram multiple immune checkpoint interactions on a cellular level. Such a candidate may be able to replace future immune checkpoint therapeutic regimes composed of both stimulatory- and inhibitory-receptor-targeting antibodies. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000747115200039 | Publication Date | 2021-11-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1936-0851 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 13.942 | Times cited | 11 | Open Access | OpenAccess |
Notes | A.A.W. is the grateful recipient of a Maplethorpe Fellowship. K.A.J. acknowledges funding from the British Council (Newton Fund, 337313), Wellcome Trust (WT103913), and the Cancer Research UK King’s Health Partners Centre at King’s College London. Financial support is acknowledged from the European Commission under the Horizon 2020 Programme, by means of Grant Agreement No. 731019 (EUSMI). Images were drawn on BioRender.com. | Approved | Most recent IF: 13.942 | ||
Call Number | EMAT @ emat @c:irua:183950 | Serial | 6829 | ||
Permanent link to this record |