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Author Wang, L.; Wen, D.-Q.; Zhang, Q.-Z.; Song, Y.-H.; Zhang, Y.-R.; Wang, Y.-N. pdf  url
doi  openurl
  Title (down) Disruption of self-organized striated structure induced by secondary electron emission in capacitive oxygen discharges Type A1 Journal article
  Year 2019 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T  
  Volume 28 Issue 5 Pages 055007  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Self-organized striated structure has been observed experimentally and numerically in CF4 plasmas in radio-frequency capacitively coupled plasmas recently (Liu et al 2016 Phys. Rev. Lett. 116 255002). In this work, the striated structure is investigated in a capacitively coupled oxygen discharge with the introduction of the effect from the secondary electron emission, based on a particle-in-cell/Monte Carlo collision model. As we know, the transport of positive and negative ions plays a key role in the formation of striations in electronegative gases, for which, the electronegativity needs to be large enough. As the secondary electron emission increases, electrons in the sheaths gradually contribute more ionization to the discharge. Meanwhile, the increase of the electron density, especially in the plasma bulk, leads to an increased electrical conductivity and a reduced bulk electric field, which would shield the ions' mobility. These changes result in enlarged striation gaps. And then, with more emitted electrons, obvious disruption of the striations is observed accompanied with a transition of electron heating mode. Due to the weakened field, the impact ionization in the plasma bulk is attenuated, compared with the enhanced ionization caused by secondary electrons. This would lead to the electron heating mode transition from striated (STR) mode to gamma-mode. Besides, our investigation further reveals that gamma-mode is more likely to dominate the discharge under high gas pressures or driving voltages.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000467827800001 Publication Date 2019-04-09  
  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 2 Open Access Not_Open_Access: Available from 13.05.2020  
  Notes Approved Most recent IF: 3.302  
  Call Number UA @ admin @ c:irua:160365 Serial 5270  
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Author Cui, W.; Lin, W.; Lu, W.; Liu, C.; Gao, Z.; Ma, H.; Zhao, W.; Van Tendeloo, G.; Zhao, W.; Zhang, Q.; Sang, X. url  doi
openurl 
  Title (down) Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps Type A1 Journal article
  Year 2023 Publication Nature communications Abbreviated Journal  
  Volume 14 Issue 1 Pages 554-10  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Weak interlayer van der Waals (vdW) bonding has significant impact on the surface/interface structure, electronic properties, and transport properties of vdW layered materials. Unraveling the complex atomistic dynamics and structural evolution at vdW surfaces is therefore critical for the design and synthesis of the next-generation vdW layered materials. Here, we show that Ge/Bi cation diffusion along the vdW gap in layered GeBi2Te4 (GBT) can be directly observed using in situ heating scanning transmission electron microscopy (STEM). The cation concentration variation during diffusion was correlated with the local Te-6 octahedron distortion based on a quantitative analysis of the atomic column intensity and position in time-elapsed STEM images. The in-plane cation diffusion leads to out-of-plane surface etching through complex structural evolutions involving the formation and propagation of a non-centrosymmetric GeTe2 triple layer surface reconstruction on fresh vdW surfaces, and GBT subsurface reconstruction from a septuple layer to a quintuple layer. Our results provide atomistic insight into the cation diffusion and surface reconstruction in vdW layered materials. Weak interlayer van der Waals (vdW) bonding has significant impact on the structure and properties of vdW layered materials. Here authors use in-situ aberration-corrected ADF-STEM for an atomistic insight into the cation diffusion in the vdW gaps and the etching of vdW surfaces at high temperatures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001076227200001 Publication Date 2023-02-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 16.6 Times cited Open Access  
  Notes Approved Most recent IF: 16.6; 2023 IF: 12.124  
  Call Number UA @ admin @ c:irua:201342 Serial 9021  
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Author Zhang, Q.; De Clippeleir, H.; Su, C.; Al-Omari, A.; Wett, B.; Vlaeminck, S.E.; Murthy, S. pdf  doi
openurl 
  Title (down) Deammonification for digester supernatant pretreated with thermal hydrolysis : overcoming inhibition through process optimization Type A1 Journal article
  Year 2016 Publication Applied microbiology and biotechnology Abbreviated Journal  
  Volume 100 Issue 12 Pages 5595-5606  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract The thermal hydrolysis process (THP) has been proven to be an excellent pretreatment step for an anaerobic digester (AD), increasing biogas yield and decreasing sludge disposal. The goal of this work was to optimize deammonification for efficient nitrogen removal despite the inhibition effects caused by the organics present in the THP-AD sludge filtrate (digestate). Two sequencing batch reactors were studied treating conventional digestate and THP-AD digestate, respectively. Improved process control based on higher dissolved oxygen set-point (1 mg O-2/L) and longer aeration times could achieve successful treatment of THP-AD digestate. This increased set-point could overcome the inhibition effect on aerobic ammonium-oxidizing bacteria (AerAOB), potentially caused by particulate and colloidal organics. Moreover, based on the mass balance, anoxic ammonium-oxidizing bacteria (AnAOB) contribution to the total nitrogen removal decreased from 97 +/- A 1 % for conventional to 72 +/- A 5 % for THP-AD digestate treatment, but remained stable by selective AnAOB retention using a vibrating screen. Overall, similar total nitrogen removal rates of 520 +/- A 28 mg N/L/day at a loading rate of 600 mg N/L/day were achieved in the THP-AD reactor compared to the conventional digestate treatment operating at low dissolved oxygen (DO) (0.38 +/- A 0.10 mg O-2/L).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000376456700033 Publication Date 2016-02-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0175-7598; 1432-0614 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:134166 Serial 7755  
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Author Zhang, Y.; Jiang, W.; Zhang, Q.Z.; Bogaerts, A. pdf  doi
openurl 
  Title (down) Computational study of plasma sustainability in radio frequency micro-discharges Type A1 Journal article
  Year 2014 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 115 Issue 19 Pages 193301-193311  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract We apply an implicit particle-in-cell Monte-Carlo (PIC-MC) method to study a radio-frequency argon microdischarge at steady state in the glow discharge limit, in which the microdischarge is sustained by secondary electron emission from the electrodes. The plasma density, electron energy distribution function (EEDF), and electron temperature are calculated in a wide range of operating conditions, including driving voltage, microdischarge gap, and pressure. Also, the effect of gap size scaling (in the range of 50-1000 μm) on the plasma sustaining voltage and peak electron density at atmospheric pressure is examined, which has not been explored before. In our simulations, three different EEDFs, i.e., a so-called three temperature hybrid mode, a two temperature α mode, and a two temperature γ mode distribution, are identified at different gaps and voltages. The maximum sustaining voltage to avoid a transition from the glow mode to an arc is predicted, as well as the minimum sustaining voltage for a steady glow discharge. Our calculations elucidate that secondary electrons play an essential role in sustaining the discharge, and as a result the relationship between breakdown voltage and gap spacing is far away from the Paschen law at atmospheric pressure.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000336920200010 Publication Date 2014-05-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979;1089-7550; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 11 Open Access  
  Notes Approved Most recent IF: 2.068; 2014 IF: 2.183  
  Call Number UA @ lucian @ c:irua:116948 Serial 458  
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Author Zhang, Q.-Z.; Bogaerts, A. pdf  url
doi  openurl
  Title (down) Capacitive electrical asymmetry effect in an inductively coupled plasma reactor Type A1 Journal Article
  Year 2018 Publication Plasma Sources Science & Technology Abbreviated Journal Plasma Sources Sci T  
  Volume 27 Issue 10 Pages 105019  
  Keywords A1 Journal Article; electrical asymmetry effect, inductively coupled plasma, self-bias, independent control of the ion fluxes and ion energy; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;  
  Abstract The electrical asymmetry effect is realized by applying multiple frequency power sources

(13.56 MHz and 27.12 MHz) to a capacitively biased substrate electrode in a specific inductively

coupled plasma reactor. On the one hand, by adjusting the phase angle θ between the multiple

frequency power sources, an almost linear self-bias develops on the substrate electrode, and

consequently the ion energy can be well modulated, while the ion flux stays constant within a

large range of θ. On the other hand, the plasma density and ion flux can be significantly

modulated by tuning the inductive power supply, while only inducing a small change in the self-

bias. Independent control of self-bias/ion energy and ion flux can thus be realized in this specific

inductively coupled plasma reactor.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000448434100001 Publication Date 2018-10-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1361-6595 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.302 Times cited 1 Open Access Not_Open_Access  
  Notes We acknowledge financial support from the European Marie Skłodowska-Curie Individual Fellowship within H2020 (Grant Agreement 702604). This work was carried out in part 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) and the University of Antwerp. Approved Most recent IF: 3.302  
  Call Number PLASMANT @ plasmant @c:irua:155506 Serial 5069  
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Author Bogaerts, A.; Zhang, Q.-Z.; Zhang, Y.-R.; Van Laer, K.; Wang, W. pdf  url
doi  openurl
  Title (down) Burning questions of plasma catalysis: Answers by modeling Type A1 Journal article
  Year 2019 Publication Catalysis today Abbreviated Journal Catal Today  
  Volume 337 Issue Pages 3-14  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Plasma catalysis is promising for various environmental, energy and chemical synthesis applications, but the underlying mechanisms are far from understood. Modeling can help to obtain a better insight in these mechanisms. Some burning questions relate to the plasma behavior inside packed bed reactors and whether plasma can penetrate into catalyst pores. In this paper, we try to provide answers to these questions, by means of both fluid modeling and particle-in-cell/Monte Carlo collision simulations. We present a short overview of recent findings obtained in our group by means of modeling, i.e., the enhanced electric field near the contact points and the streamer propagation through the packing in packed bed reactors, as well as the plasma behavior in catalyst pores, to determine the minimum pore size in which plasma streamers can penetrate.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000482179500002 Publication Date 2019-04-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0920-5861 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.636 Times cited 7 Open Access  
  Notes University of Antwerp, the European Marie Skłodowska-Curie Individual Fellowships “GlidArc”; “CryoEtch” within Horizon2020, 657304 702604 ;We would like to thank H.-H. Kim for performing experiments to validate the modeling of streamer propagation in packed bed reactors. We acknowledge financial support from the TOP-BOF project of the University of Antwerp, the European Marie Skłodowska-Curie Individual Fellowships “GlidArc” and “CryoEtch” within Horizon2020 (Grant Nos. 657304 and 702604). Approved Most recent IF: 4.636  
  Call Number PLASMANT @ plasmant @c:irua:161775 Serial 5356  
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Author Sun, C.; Street, M.; Zhang, C.; Van Tendeloo, G.; Zhao, W.; Zhang, Q. pdf  url
doi  openurl
  Title (down) Boron structure evolution in magnetic Cr₂O₃ thin films Type A1 Journal article
  Year 2022 Publication Materials Today Physics Abbreviated Journal  
  Volume 27 Issue Pages 100753-100757  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract B substituting O in antiferromagnetic Cr2O3 is known to increase the Ne ' el temperature, whereas the actual B dopant site and the corresponding functionality remains unclear due to the complicated local structure. Herein, A combination of electron energy loss spectroscopy and first-principles calculations were used to unveil B local structures in B doped Cr2O3 thin films. B was found to form either magnetic active BCr4 tetrahedra or various inactive BO3 triangles in the Cr2O3 lattice, with a* and z* bonds exhibiting unique spectral features. Identification of BO3 triangles was achieved by changing the electron momentum transfer to manipulate the differential cross section for the 1s-z* and 1s-a* transitions. Modeling the experimental spectra as a linear combination of simulated B K edges reproduces the experimental z* / a* ratios for 15-42% of the B occupying the active BCr4 structure. This result is further supported by first-principles based thermodynamic calculations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000827323200003 Publication Date 2022-06-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2542-5293 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 11.5 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 11.5  
  Call Number UA @ admin @ c:irua:189660 Serial 7078  
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Author Wei, P.; Ke, B.; Xing, L.; Li, C.; Ma, S.; Nie, X.; Zhu, W.; Sang, X.; Zhang, Q.; Van Tendeloo, G.; Zhao, W. pdf  doi
openurl 
  Title (down) Atomic-resolution interfacial structures and diffusion kinetics in Gd/Bi0.5Sb1.5Te3 magnetocaloric/thermoelectric composites Type A1 Journal article
  Year 2020 Publication Materials Characterization Abbreviated Journal Mater Charact  
  Volume 163 Issue Pages 110240-110248  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract The demand of a full solid-state cooling technology based on magnetocaloric and thermoelectric effects has led to a growing interest in screening candidate materials with high-efficiency cooling performance, which also stimulates the exploration of magnetocaloric/thermoelectric hybrid cooling materials. A series of Gd/Bi0.5Sb1.5Te3 composites was fabricated in order to develop the hybrid cooling technology. The chemical composition, phase structure and diffusion kinetics across the reaction layers in Gd/Bi0.5Sb1.5Te3 composites were analyzed at different reaction temperatures. Micro-area elemental analysis indicates that the formation of interfacial phases is dominated by the diffusion of Gd and Te while the diffusion of Bi and Sb is impeded. The interfacial phases, including GdTe2, GdTe3, and intermediate phases GdTex, are identified by atomic-resolution electron microscopy. The concentration modulation of Gd and Te is adapted by altering the stacking of the Te square-net sheets and the corrugated GdTe sheets. Boltzmann-Marano analysis was applied to reveal the diffusion kinetics of Gd and Te in the interfacial layers. The diffusion coefficients of Te in GdTe2 and GdTe3 are much higher than that of Gd while in GdTe the situation is reversed. This study provides a clear picture to understand the interfacial phase structures down to an atomic scale as well as the interfacial diffusion kinetics in Gd/Bi0.5Sb1.5Te3 hybrid cooling materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000551341700045 Publication Date 2020-03-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.7 Times cited 1 Open Access Not_Open_Access  
  Notes ; This work was supported by National Natural Science Foundation of China (Nos. 91963122, 11834012, 51620105014, 51521001, 51902237), National Key Research and Development Program of China (No. 2018YFB0703603), the Fundamental Research Funds for the Central Universities (WUT: 2019III012GX, 183101006). XRD and EPMA experiments were performed at the Center for Materials Research and Testing of Wuhan University of Technology. ; Approved Most recent IF: 4.7; 2020 IF: 2.714  
  Call Number UA @ admin @ c:irua:171317 Serial 6456  
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Author Chen, C.; Sang, X.; Cui, W.; Xing, L.; Nie, X.; Zhu, W.; Wei, P.; Hu, Z.-Y.; Zhang, Q.; Van Tendeloo, G.; Zhao, W. pdf  doi
openurl 
  Title (down) Atomic-resolution fine structure and chemical reaction mechanism of Gd/YbAl₃ thermoelectric-magnetocaloric heterointerface Type A1 Journal article
  Year 2020 Publication Journal Of Alloys And Compounds Abbreviated Journal J Alloy Compd  
  Volume 831 Issue Pages 154722-154728  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Thermoelectric materials and magnetocaloric materials are promising candidates for solid-state refrigeration applications. The combination of thermoelectric and magnetocaloric effects could potentially lead to more efficient refrigeration techniques. We designed and successfully synthesized Gd/YbAl3 composites using a YbAl3 matrix with good low-temperature thermoelectric performance and Gd microspheres with a high magnetocaloric performance, using a sintering condition of 750 degrees C and 50 MPa. Using aberration-corrected scanning transmission electron microscopy (STEM), it was discovered that the heterointerface between Gd and YbAl 3 is composed of five sequential interfacial layers: GdAl3, GdAl2, GdAl, Gd3Al2, and Gd3Al. The diffusion of Al atoms plays a crucial role in the formation of these interfacial layers, while Yb or Gd do not participate in the interlayer diffusion. This work provides the essential structural information for further optimizing and designing high-performance composites for thermoelectric-magnetocaloric hybrid refrigeration applications. (C) 2020 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000531727900005 Publication Date 2020-03-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-8388 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.2 Times cited 1 Open Access Not_Open_Access  
  Notes ; This work was supported by National Natural Science Foundation of China (Nos. 11834012, 51620105014, 91963207, 91963122, 51902237) and National Key R&D Program of China (No. 2018YFB0703603, 2019YFA0704903, SQ2018YFE010905). EPMA experiments were performed at the Center for Materials Research and Testing of Wuhan University of Technology. The S/TEM work was performed at the Nanostructure Research Center (NRC), which is supported by the Fundamental Research Funds for the Central Universities (WUT: 2019III012GX). ; Approved Most recent IF: 6.2; 2020 IF: 3.133  
  Call Number UA @ admin @ c:irua:169447 Serial 6455  
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