“Mode Transition of Filaments in Packed-Bed Dielectric Barrier Discharges”. Gao M, Zhang Y, Wang H, Guo B, Zhang Q, Bogaerts A, Catalysts 8, 248 (2018). http://doi.org/10.3390/catal8060248
Abstract: We investigated the mode transition from volume to surface discharge in a packed bed dielectric barrier discharge reactor by a two-dimensional particle-in-cell/Monte Carlo collision method. The calculations are performed at atmospheric pressure for various driving voltages and for gas mixtures with different N2 and O2 compositions. Our results reveal that both a change of the driving voltage and gas mixture can induce mode transition. Upon increasing voltage, a mode transition from hybrid (volume+surface) discharge to pure surface discharge occurs, because the charged species can escape much more easily to the beads and charge the bead surface due to the strong electric field at high driving voltage. This significant surface charging will further enhance the tangential component of the electric field along the dielectric bead surface, yielding surface ionization waves (SIWs). The SIWs will give rise to a high concentration of reactive species on the surface, and thus possibly enhance the surface activity of the beads, which might be of interest for plasma catalysis. Indeed, electron impact excitation and ionization mainly take place near the bead surface. In addition, the propagation speed of SIWs becomes faster with increasing N2 content in the gas mixture, and slower with increasing O2 content, due to the loss of electrons by attachment to O2
molecules. Indeed, the negative O-2 ion density produced by electron impact attachment is much higher than the electron and positive O+2 ion density. The different ionization rates between N2 and O2 gases will create different amounts of electrons and ions on the dielectric bead surface, which might also have effects in plasma catalysis.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.082
Times cited: 7
DOI: 10.3390/catal8060248
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“Toward energy autarky : carbon redirection coupled with shortcut nitrogen processes”. De Clippeleir H, Vlaeminck SE, Courtens ENP, Jimenez J, Wadhawan T, Zhang Q page 129 (2015).
Keywords: H3 Book chapter; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Minimizing recalcitrant organics and maximizing nitrogen removal linked to advanced biosolids processing at Blue Plains WWTP”. Zhang Q, Higgins MJ, Vlaeminck SE, DeBarbadillo C, Suzuki R, Kharkar SM, Al-Omari A, Wett B, Chandran K, Murthy S, De Clippeleir H, , 12 p.
T2 (2017)
Keywords: P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Sidestream deammonification on thermal hydrolysis process digestate : strategies to overcome nitritation inhibition”. Zhang Q, De Clippeleir H, Al-Omari A, Wett B, Vlaeminck SE, Murthy S, , 11 p.
T2 (2015)
Keywords: P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Inhibition mechanisms affecting deammonification of dewatering filtrate from thermally hydrolyzed digested solid”. Zhang Q, De Clippeleir H, DeBarbadillo C, Su C, Al-Omari A, Wett B, Chandran K, Vlaeminck SE, Murthy S, , 9 p.
T2 (2016)
Keywords: P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Mechanistic understanding of microbial activity inhibition : case study on sidestream deammonification for digester supernatant pretreated by thermal hydrolysis”. Zhang Q, De Clippeleir H, Shaw A, DeBarbadillo C, Su C, Al-Omari A, Wett B, Chandran K, Vlaeminck SE, Murthy S, , 5 p.
T2 (2016)
Keywords: P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Startup strategies of deammonification reactors treating reject water from thermally hydrolyzed solids”. Zhang Q, Vlaeminck SE, DeBarbadillo C, Suzuki R, Kharkar SM, Al-Omari A, Wett B, Chandran K, Murthy S, De Clippeleir H, , 5 p.
T2 (2017)
Keywords: P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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“Burning questions of plasma catalysis: Answers by modeling”. Bogaerts A, Zhang Q-Z, Zhang Y-R, Van Laer K, Wang W, Catalysis today 337, 3 (2019). http://doi.org/10.1016/j.cattod.2019.04.077
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.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.636
Times cited: 7
DOI: 10.1016/j.cattod.2019.04.077
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“Ferroelectric engineering : enhanced thermoelectric performance by local structural heterogeneity”. Meng X, Chen S, Peng H, Bai H, Zhang S, Su X, Tan G, Van Tendeloo G, Sun Z, Zhang Q, Tang X, Wu J, Science China : materials (2022). http://doi.org/10.1007/S40843-021-1927-9
Abstract: Although traditional ferroelectric materials are usually dielectric and nonconductive, GeTe is a typical ferroelectric semiconductor, possessing both ferroelectric and semiconducting properties. GeTe is also a widely studied thermoelectric material, whose performance has been optimized by doping with various elements. However, the impact of the ferroelectric domains on the thermoelectric properties remains unclear due to the difficulty to directly observe the ferroelectric domains and their evolutions under actual working conditions where the material is exposed to high temperatures and electric currents. Herein, based on in-situ investigations of the ferroelectric domains and domain walls in both pure and Sb-doped GeTe crystals, we have been able to analyze the dynamic evolution of the ferroelectric domains and domain walls, exposed to an electric field and temperature. Local structural heterogeneities and nano-sized ferroelectric domains are generated due to the interplay of the Sb3+ dopant and the Ge-vacancies, leading to the increased number of charged domain walls and a much improved thermoelectric performance. This work reveals the fundamental mechanism of ferroelectric thermoelectrics and provides insights into the decoupling of previously interdependent properties such as thermo-power and electrical conductivity.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.1
DOI: 10.1007/S40843-021-1927-9
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