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Author Gonzalez-Quiroga, A.; Kulkarni, S.R.; Vandewalle, L.; Perreault, P.; Goel, C.; Heynderickx, G.J.; van Geem, K.M.; Marin, G.B.
Title (down) Azimuthal and radial flow patterns of 1g-Geldart B-type particles in a gas-solid vortex reactor Type A1 Journal article
Year 2019 Publication Powder technology Abbreviated Journal
Volume 354 Issue Pages 410-422
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Processes requiring intensive interfacial momentum, mass and heat exchange between gases and particulate solids can be greatly enhanced by operating in a centrifugal field. This is realized in the Gas-Solid Vortex Reactor (GSVR) with centrifugal accelerations up to two orders of magnitude higher than the Earth's gravitational acceleration. Here, the flow patterns of two 1g-Geldart B-type particles are experimentally assessed, over the gas inlet velocity range 82–126 m s−1, in an 80 mm diameter and 15 mm height GSVR. The particles are monosized aluminum spheres of 0.5 mm diameter, and walnut shell in the sieve fraction 0.50–0.56 mm and aspect ratio 1.3 ± 0.2. Two dimensional Particle Image Velocimetry combined with Digital Image Analysis and pressure measurements revealed that periodic fluctuations in solids azimuthal and radial velocity between gas inlet slots are strongly related to the average solids azimuthal velocity and bed uniformity. Aluminum particles feature steeper changes in azimuthal velocity and more attenuated changes in radial velocity than walnut shell particles. Within the assessed gas inlet velocity range the solids bed of aluminum exhibits average azimuthal velocities and bed voidages 40–50% and ≈10% lower than those of walnut shell. The aerodynamic response time of the particles, i.e. ρsdp2/18μg, emerged as an important parameter to assess the influence of the carrier gas jet on the radial deflection of the particles and the interaction solids bed-outer wall. Too low aerodynamic response time relates to nonuniformity in bed voidage due to solids radial velocity fluctuations. Excessive aerodynamic response time indicates low solids azimuthal velocities due to solids bed-outer wall friction.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000490625500041 Publication Date 2019-06-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0032-5910 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:162120 Serial 7543
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Author Kulkarni, S.; Gonzalez-Quiroga, A.; Nuñez, M.; Schuerewegen, C.; Perreault, P.; Goel, C.; Heynderickx, G.J.; Van Geem, K.M.; Marin, G.B.
Title (down) An experimental and numerical study of the suppression of jets, counterflow, and backflow in vortex units Type A1 Journal article
Year 2019 Publication AIChE journal Abbreviated Journal
Volume 65 Issue 8 Pages e16614-13
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Vortex units are commonly considered for various single and multiphase applications due to their process intensification capabilities. The transition from gas‐only flow to gas–solid flow remains largely unexplored nonetheless. During this transition, primary flow phenomenon, jets, and secondary flow phenomena, counterflow and backflow, are substantially reduced, before a rotating solids bed is established. This transitional flow regime is referred to as the vortex suppression regime. In the present work, this flow transition is identified and validated through experimental and computational studies in two vortex units with a scale differing by a factor of 2, using spherical aluminum and alumina particles. This experimental data supports the proposed theoretical particle monolayer solids loading that allows estimation of vortex suppression regime solids capacity for any vortex unit. It is shown that the vortex suppression regime is established at a solids loading theoretically corresponding to a monolayer being formed in the unit for 1g‐Geldart D‐ and 1g‐Geldart B‐type particles. The model closely agrees with experimental vortex suppression range for both aluminum and alumina particles. The model, as well as the experimental data, shows that the flow suppression regime depends on unit dimensions, particle diameter, and particle density but is independent of gas flow rate. This combined study, based on experimental and computational data and on a theoretical model, reveals the vortex suppression to be one of the basic operational parameters to study flow in a vortex unit and that a simple monolayer model allows to estimate the needed solids loading for any vortex device to induce this flow transition.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000474620800026 Publication Date 2019-04-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0001-1541 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:162121 Serial 7945
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Author Kante, M.V.; Weber, M.L.; Ni, S.; van den Bosch, I.C.G.; van der Minne, E.; Heymann, L.; Falling, L.J.; Gauquelin, N.; Tsvetanova, M.; Cunha, D.M.; Koster, G.; Gunkel, F.; Nemsak, S.; Hahn, H.; Estrada, L.V.; Baeumer, C.
Title (down) A high-entropy oxide as high-activity electrocatalyst for water oxidation Type A1 Journal article
Year 2023 Publication ACS nano Abbreviated Journal
Volume 17 Issue 6 Pages 5329-5339
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract High-entropy materials are an emerging pathway in the development of high-activity (electro)catalysts because of the inherent tunability and coexistence of multiple potential active sites, which may lead to earth-abundant catalyst materials for energy-efficient electrochemical energy storage. In this report, we identify how the multication composition in high-entropy perovskite oxides (HEO) contributes to high catalytic activity for the oxygen evolution reaction (OER), i.e., the key kinetically limiting half-reaction in several electrochemical energy conversion technologies, including green hydrogen generation. We compare the activity of the (001) facet of LaCr0.2Mn0.2Fe0.2Co0.2Ni0.2O3-delta with the parent compounds (single B-site in the ABO3 perovskite). While the single B-site perovskites roughly follow the expected volcano-type activity trends, the HEO clearly outperforms all of its parent compounds with 17 to 680 times higher currents at a fixed overpotential. As all samples were grown as an epitaxial layer, our results indicate an intrinsic composition-function relationship, avoiding the effects of complex geometries or unknown surface composition. In-depth X-ray photoemission studies reveal a synergistic effect of simultaneous oxidation and reduction of different transition metal cations during the adsorption of reaction intermediates. The surprisingly high OER activity demonstrates that HEOs are a highly attractive, earth-abundant material class for high-activity OER electrocatalysts, possibly allowing the activity to be fine-tuned beyond the scaling limits of mono-or bimetallic oxides.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000953440900001 Publication Date 2023-03-13
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 17.1 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 17.1; 2023 IF: 13.942
Call Number UA @ admin @ c:irua:196097 Serial 7390
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Author Thiruvottriyur Shanmugam, S.; Steijlen, A.; Laurijssen, D.; Campos, R.; Steckel, J.; Daems, W.; Bassini, S.; Daems, E.; De Wael, K.
Title (down) A 96-well LED array for multiplexed photoelectrochemical detection of nucleic acids Type A1 Journal article
Year 2024 Publication Analytical chemistry Abbreviated Journal
Volume 96 Issue 38 Pages 15091-15096
Keywords A1 Journal article; Co-Design of Cyber-Physical Systems (Cosys-Lab); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab); Antwerp engineering, PhotoElectroChemistry & Sensing (A-PECS)
Abstract Photoelectrochemical detection of nucleic acid-based cancer biomarkers offers opportunities for highly sensitive, selective, and fast quantitative detection using low-cost measurement instruments. In order to establish itself as a standard method for identifying and quantifying nucleic acids, we have developed a multiplexing strategy using LED technology for photoelectrochemical detection in 96 samples simultaneously. A dedicated setup based on the 96-well plate configuration with a custom-made 96-well LED array was developed. Subsequently, a proof-of-concept study was performed for three miRNAs that are associated with prostate cancer, i.e., miRNA-141, miRNA-145, and miRNA-375. First, measurements with photosensitizer chlorin e6 and redox reporter hydroquinone free in solution proved the proper functioning of the multiplexed detection. Second, the photoelectrochemical detection of the three miRNAs at 24 nM levels was successfully demonstrated. Thereafter, linear calibration curves (R2 > 0.9 for all analytes) were made with plasma spiked with 8–500 pM miRNA. This work presents the first system for multiplexed high-throughput photoelectrochemical detection, allowing it potentially to become a cost-effective and faster alternative to RT-qPCR and gene sequencing techniques in the future.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record
Impact Factor 7.4 Times cited Open Access
Notes Approved Most recent IF: 7.4; 2024 IF: 6.32
Call Number UA @ admin @ c:irua:208164 Serial 9275
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