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Sun, J.-Y.; Wen, D.-Q.; Zhang, Q.-Z.; Liu, Y.-X.; Wang, Y.-N. |
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Title |
The effects of electron surface interactions in geometrically symmetric capacitive RF plasmas in the presence of different electrode surface materials |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physics of plasmas |
Abbreviated Journal |
Phys Plasmas |
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Volume |
26 |
Issue |
6 |
Pages |
063505 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract  |
Particle-in-cell/Monte Carlo collision (PIC/MCC) simulations are performed to investigate the asymmetric secondary electron emission (SEE) effects when electrons strike two different material electrodes in low pressure capacitively coupled plasmas (CCPs). To describe the electron-surface interactions, a realistic model, considering the primary electron impact energy and angle, as well as the corresponding surface property-dependent secondary electron yields, is employed in PIC/MCC simulations. In this model, three kinds of electrons emitted from the surface are considered: (i) elastically reflected electrons, (ii) inelastically backscattered electrons, and (iii) electron induced secondary electrons (SEs, i.e., delta-electrons). Here, we examined the effects of electron-surface interactions on the ionization dynamics and plasma characteristics of an argon discharge. The discharge is driven by a voltage source of 13.56MHz with amplitudes in the range of 200-2000V. The grounded electrode material is copper (Cu) for all cases, while the powered electrode material is either Cu or silicon dioxide (SiO2). The simulations reveal that the electron impact-induced SEE is an essential process at low pressures, especially at high voltages. Different electrode materials result in an asymmetric response of SEE. Depending on the instantaneous local sheath potential and the phase of the SEE, these SEs either are reflected by the opposite sheath or strike the electrode surface, where they can induce delta-electrons upon their residual energies. It is shown that highly energetic delta-electrons contribute significantly to the ionization rate and a self-bias forms when the powered electrode material is assumed to be made of SiO2. Complex dynamics is observed due to the multiple electron-surface interaction processes and asymmetric yields of SEs in CCPs. |
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Wos |
000474440600043 |
Publication Date |
2019-06-06 |
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Abbreviated Series Title |
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Edition |
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ISSN |
1070-664x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.115 |
Times cited |
1 |
Open Access |
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Approved |
Most recent IF: 2.115 |
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Call Number |
UA @ admin @ c:irua:161353 |
Serial |
6327 |
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Author |
Mefford, J.T.; Kurilovich, A.A.; Saunders, J.; Hardin, W.G.; Abakumov, A.M.; Forslund, R.P.; Bonnefont, A.; Dai, S.; Johnston, K.P.; Stevenson, K.J. |
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Title |
Decoupling the roles of carbon and metal oxides on the electrocatalytic reduction of oxygen on La1-xSrxCoO3-\delta perovskite composite electrodes |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
21 |
Issue |
6 |
Pages |
3327-3338 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Perovskite oxides are active room-temperature bifunctional oxygen electrocatalysts in alkaline media, capable of performing the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with lower combined overpotentials relative to their precious metal counterparts. However, their semiconducting nature necessitates the use of activated carbons as conductive supports to generate applicably relevant current densities. In efforts to advance the performance and theory of oxide electrocatalysts, the chemical and physical properties of the oxide material often take precedence over contributions from the conductive additive. In this work, we find that carbon plays an important synergistic role in improving the performance of La1-xSrxCoO3- (0 x 1) electrocatalysts through the activation of O-2 and spillover of radical oxygen intermediates, HO2- and O-2(-), which is further reduced through chemical decomposition of HO2- on the perovskite surface. Through a combination of thin-film rotating disk electrochemical characterization of the hydrogen peroxide intermediate reactions (hydrogen peroxide reduction reaction (HPRR), hydrogen peroxide oxidation reaction (HPOR)) and oxygen reduction reaction (ORR), surface chemical analysis, HR-TEM, and microkinetic modeling on La1-xSrxCoO3- (0 x 1)/carbon (with nitrogen and non-nitrogen doped carbons) composite electrocatalysts, we deconvolute the mechanistic aspects and contributions to reactivity of the oxide and carbon support. |
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Wos |
000459584900049 |
Publication Date |
2019-01-18 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
1463-9076; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
5 |
Open Access |
OpenAccess |
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Notes |
; Financial support for this work was provided by the R. A. Welch Foundation (grants F-1529 and F-1319). S. D. was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. ; |
Approved |
Most recent IF: 4.123 |
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Call Number |
UA @ admin @ c:irua:158625 |
Serial |
5244 |
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Author |
Retuerto, M.; Calle-Vallejo, F.; Pascual, L.; Lumbeeck, G.; Fernandez-Diaz, M.T.; Croft, M.; Gopalakrishnan, J.; Pena, M.A.; Hadermann, J.; Greenblatt, M.; Rojas, S. |
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Title |
La1.5Sr0.5NiMn0.5Ru0.5O6 double perovskite with enhanced ORR/OER bifunctional catalytic activity |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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Volume |
11 |
Issue |
24 |
Pages |
21454-21464 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Perovskites (ABO(3)) with transition metals in active B sites are considered alternative catalysts for the water oxidation to oxygen through the oxygen evolution reaction (OER) and for the oxygen reduction through the oxygen reduction reaction (ORR) back to water. We have synthesized a double perovskite (A(2)BB'O-6) with different cations in A, B, and B' sites, namely, ((La15Sr0.5)-Sr-.)(A)(Ni0.5Mn0.5)(B)(Ni0.5Ru0.5)(B)O-6 (LSNMR), which displays an outstanding OER/ORR bifunctional performance. The composition and structure of the oxide has been determined by powder X-ray diffraction, powder neutron diffraction, and transmission electron microscopy to be monoclinic with the space group P2(1)/n and with cationic ordering between the ions in the B and B' sites. X-ray absorption near-edge spectroscopy suggests that LSNMR presents a configuration of similar to Ni2+, similar to Mn4+, and similar to Ru5+. This bifunctional catalyst is endowed with high ORR and OER activities in alkaline media, with a remarkable bifunctional index value of similar to 0.83 V (the difference between the potentials measured at -1 mA cm(-2) for the ORR and +10 mA cm(-2) for the OER). The ORR onset potential (E-onset) of 0.94 V is among the best reported to date in alkaline media for ORR-active perovskites. The ORR mass activity of LSNMR is 1.1 A g(-1) at 0.9 V and 7.3 A g(-1) at 0.8 V. Furthermore, LSNMR is stable in a wide potential window down to 0.05 V. The OER potential to achieve a current density of 10 mA cm(-2) is 1.66 V. Density functional theory calculations demonstrate that the high ORR/OER activity of LSNMR is related to the presence of active Mn sites for the ORR- and Ru-active sites for the OER by virtue of the high symmetry of the respective reaction steps on those sites. In addition, the material is stable to ORR cycling and also considerably stable to OER cycling. |
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Wos |
000472683300019 |
Publication Date |
2019-05-30 |
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Abbreviated Series Title |
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Series Volume |
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Edition |
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ISSN |
1944-8244 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.504 |
Times cited |
12 |
Open Access |
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Notes |
; This work was supported by the ENE2016-77055-C3-3-R project from the Spanish Ministry of Economy and Competitiveness (MINECO) and PIE 201480E122 from CSIC. M.R. thanks MINECO's Juan de la Cierva program for a grant (FPDI-2013-17582). F.C.-V. thanks the Spanish MEC for a Ramon y Cajal research contract (RYC-2015-18996). M.G. acknowledges the support from NSF-DMR-1507252 grant, NJ, USA. ; |
Approved |
Most recent IF: 7.504 |
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Call Number |
UA @ admin @ c:irua:161320 |
Serial |
5400 |
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Author |
Wardenier, N.; Gorbanev, Y.; Van Moer, I.; Nikiforov, A.; Van Hulle, S.W.H.; Surmont, P.; Lynen, F.; Leys, C.; Bogaerts, A.; Vanraes, P. |
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Title |
Removal of alachlor in water by non-thermal plasma: Reactive species and pathways in batch and continuous process |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Water research |
Abbreviated Journal |
Water Res |
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Volume |
161 |
Issue |
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Pages |
549-559 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Pesticides are emerging contaminants frequently detected in the aquatic environment. In this work, a novel approach combining activated carbon adsorption, oxygen plasma treatment and ozonation was studied for the removal of the persistent chlorinated pesticide alachlor. A comparison was made between the removal efficiency and energy consumption for two different reactor operation modes: batchrecirculation and single-pass mode. The kinetics study revealed that the insufficient removal of alachlor by adsorption was significantly improved in terms of degradation efficiency and energy consumption when combined with the plasma treatment. The best efficiency (ca. 80% removal with an energy cost of 19.4 kWh mÀ3) was found for the single-pass operational mode of the reactor. In the batch-recirculating process, a complete elimination of alachlor by plasma treatment was observed after 30 min of treatment. Analysis of the reactive species induced by plasma in aqueous solutions showed that the decomposition of alachlor mainly occurred through a radical oxidation mechanism, with a minor contribution of long-living oxidants (O3, H2O2). Investigation of the alachlor oxidation pathways revealed six different oxidation mechanisms, including the loss of aromaticity which was never before reported for plasma-assisted degradation of aromatic pesticides. It was revealed that the removal rate and energy cost could be further improved with more than 50% by additional O3 gas bubbling in the solution reservoir. |
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Wos |
000475999400054 |
Publication Date |
2019-06-10 |
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Series Editor |
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Abbreviated Series Title |
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Edition |
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ISSN |
0043-1354 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.942 |
Times cited |
2 |
Open Access |
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Notes |
PlasmaTex project IWT, 1408/2 ; the European Marie Sklodowska-Curie Individual Fellowship within Horizon2020, 743151 ; Flemish Knowledge Centre Water; This work was financially supported by the PlasmaTex project IWT 1408/2 and the European Marie Sklodowska-Curie Individual Fellowship within Horizon2020 (‘LTPAM’, grant no. 743151). This research was initiated within the LED H2O project which is financially supported by the Flemish Knowledge Centre Water (Vlakwa). |
Approved |
Most recent IF: 6.942 |
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Call Number |
PLASMANT @ plasmant @c:irua:161173 |
Serial |
5288 |
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Author |
van Walsem, J. |
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Title |
Design and optimization of a photocatalytic reactor for air purification in ventilation systems |
Type |
Doctoral thesis |
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Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
158 p. |
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Keywords |
Doctoral thesis; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Photocatalysis has been labeled for decades as a promising technique for air purification. The principle seems straightforward and requires a photocatalyst that is immobilized on a substrate, and one or more UV sources to activate the photocatalyst. No waste products are produced, the reactions occur in mild conditions and the supplies are relatively cheap. Yet it seems that the commercialization of photocatalytic systems does not break through on the global market. The aim of this thesis is to identify and tackle the bottlenecks that impede commercialization from an application-oriented approach. The problem of indoor air pollution is enhanced by the fact that people spend more and more time indoors and that ventilation is kept to a minimum as an energy-saving measure. This inevitably leads to an accumulation of volatile organic compounds (VOCs) that are emitted by e.g. building materials, paint and furniture. Human exposure to VOCs is directly related to the sick building syndrome leading to complaints such as headache, fatigue, dizziness and lack of concentration. In addition, exposure to VOCs is related to serious long-term health effects such as cancer or respiratory diseases. Therefore, significant research efforts are focused on advanced indoor air purification methods. Integration or retrofitting of a photocatalytic (PCO) air purifying unit into heating, ventilation and air conditioning (HVAC) equipment has been chosen as an interesting approach. As a starting point of this thesis, the operational conditions of a ventilation system were mapped. These systems are characterized by high flow rates and the necessity of minimal pressure losses. Pressure losses increase the energy demand and can lead to failure of the ventilation fan and thereby undermine the proper functioning of the ventilation system. A suitable substrate must allow the contaminated air to pass through with a minimal pressure drop, allow sufficient contact time between VOC and photocatalyst, have a large surface area available for coating with excellent adhesion, and be transparent to UV light. Therefore, the permeability and the available exposed surface were selected as main selection criteria. After a thorough quantitative analysis of potential substrates, borosilicate glass tubes were selected. Glass tubes can easily be stacked to constitute a transparent monolithic multi-tube reactor, with their length parallel to the air flow in order to minimize the pressure drop. Moreover, borosilicate glass is relatively inexpensive and has excellent UV-A light transmitting properties. Based on a literature study, a sol-gel coating procedure was selected that is extremely suitable for coating glass substrates. The next step was to optimize the amount of P25 (commercial titanium dioxide) in the photocatalytic sol-gel coating for its application. More P25 in the sol-gel coating results in a higher adsorption capacity and consequently a higher photocatalytic activity, but greatly reduces the transparency of the coating. After an in-depth study, the concentration of 10 g L-1 P25 was selected as the most feasible for multi-tube reactors. Since the operation of photocatalytic reactors is based on a complex interaction of physical and chemical processes, mathematical models were developed, supported by experimental data, that include all these phenomena as a tool for reactor design and optimization. By making use of such models, time-consuming and expensive experimental research can be minimized. However, the experimental validation of models is of utmost importance to prove its reliability and accuracy. Intrinsic kinetic parameters provide the fundamentals for these models as they describe the photocatalytic reaction rate, independent of fluid dynamics, reactor geometry and radiation field. In this work they were estimated by means of a Computational Fluid Dynamics (CFD) study, based on FTIR (Fourier-transform infrared spectroscopy) experiments with a lab scale multi-tube reactor. The kinetic parameters were validated by an alternative analytic approach, emphasizing the accuracy and reliability of the simulations. Finally, the aforementioned CFD approach, based on the simultaneously modelling of airflow, mass transfer, UV light irradiation and photocatalytic reactions, was used to obtain insights for the light source configuration in upscaled multi-tube reactors. After taking all these insights and some practical implications into account, a final upscaled multi-tube reactor design was proposed and converted into a first built prototype. Subsequently, it was evaluated according the CEN-EN-16486-1 standard for VOC removal by the external scientific research center ‘CERTECH’. The scientific results, regarding the mineralization of the VOCs and photocatalytic efficiency of the reactor, demonstrated the feasibility for indoor air purification by the upscaled multi-tube reactor and the possible implementation in ventilation systems. |
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Times cited |
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no |
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Call Number |
UA @ admin @ c:irua:160205 |
Serial |
7763 |
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Author |
Privat-Maldonado, A.; Schmidt, A.; Lin, A.; Weltmann, K.-D.; Wende, K.; Bogaerts, A.; Bekeschus, S. |
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Title |
ROS from Physical Plasmas: Redox Chemistry for Biomedical Therapy |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Oxidative medicine and cellular longevity |
Abbreviated Journal |
Oxid Med Cell Longev |
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Volume |
2019 |
Issue |
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Pages |
1-29 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Physical plasmas generate unique mixes of reactive oxygen and nitrogen species (RONS or ROS). Only a bit more than a decade ago, these plasmas, operating at body temperature, started to be considered for medical therapy with considerably little mechanistic redox chemistry or biomedical research existing on that topic at that time. Today, a vast body of evidence is available on physical plasma-derived ROS, from their spatiotemporal resolution in the plasma gas phase to sophisticated chemical and biochemical analysis of these species once dissolved in liquids. Data from<italic>in silico</italic>analysis dissected potential reaction pathways of plasma-derived reactive species with biological membranes, and<italic>in vitro</italic>and<italic>in vivo</italic>experiments in cell and animal disease models identified molecular mechanisms and potential therapeutic benefits of physical plasmas. In 2013, the first medical plasma systems entered the European market as class IIa devices and have proven to be a valuable resource in dermatology, especially for supporting the healing of chronic wounds. The first results in cancer patients treated with plasma are promising, too. Due to the many potentials of this blooming new field ahead, there is a need to highlight the main concepts distilled from plasma research in chemistry and biology that serve as a mechanistic link between plasma physics (how and which plasma-derived ROS are produced) and therapy (what is the medical benefit). This inevitably puts cellular membranes in focus, as these are the natural interphase between ROS produced by plasmas and translation of their chemical reactivity into distinct biological responses. |
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Wos |
000493001000003 |
Publication Date |
2019-10-08 |
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Abbreviated Series Title |
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Edition |
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ISSN |
1942-0900 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.593 |
Times cited |
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Open Access |
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Notes |
KW and SB acknowledge funding by the German Federal Ministry of Education and Research (grant numbers 03Z22DN11 and 03Z22DN12). The work of SB is further supported by the European Social Fund (grant number ESF/14-BM-A55-0006). APM and AB acknowledge funding by the Methusalem Project. AL acknowledges funding from the Research Foundation Flanders (grant number 12S9218N). APM thanks Yury Gorbanev for his assistance with the preparation of this review. |
Approved |
Most recent IF: 4.593 |
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Call Number |
PLASMANT @ plasmant @c:irua:163476 |
Serial |
5373 |
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Author |
Uytdenhouwen, Y.; Bal, Km.; Michielsen, I.; Neyts, Ec.; Meynen, V.; Cool, P.; Bogaerts, A. |
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Title |
How process parameters and packing materials tune chemical equilibrium and kinetics in plasma-based CO2 conversion |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
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Volume |
372 |
Issue |
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Pages |
1253-1264 |
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Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma (catalysis) reactors are increasingly being used for gas-based chemical conversions, providing an alternative method of energy delivery to the molecules. In this work we explore whether classical concepts such as
equilibrium constants, (overall) rate coefficients, and catalysis exist under plasma conditions. We specifically
investigate the existence of a so-called partial chemical equilibrium (PCE), and how process parameters and
packing properties influence this equilibrium, as well as the overall apparent rate coefficient, for CO2 splitting in
a DBD plasma reactor. The results show that a PCE can be reached, and that the position of the equilibrium, in
combination with the rate coefficient, greatly depends on the reactor parameters and operating conditions (i.e.,
power, pressure, and gap size). A higher power, higher pressure, or smaller gap size enhance both the equilibrium constant and the rate coefficient, although they cannot be independently tuned. Inserting a packing
material (non-porous SiO2 and ZrO2 spheres) in the reactor reveals interesting gap/material effects, where the
type of material dictates the position of the equilibrium and the rate (inhibition) independently. As a result, no
apparent synergistic effect or plasma-catalytic behaviour was observed for the non-porous packing materials
studied in this reaction. Within the investigated parameters, equilibrium conversions were obtained between 23
and 71%, while the rate coefficient varied between 0.027 s−1 and 0.17 s−1. This method of analysis can provide
a more fundamental insight in the overall reaction kinetics of (catalytic) plasma-based gas conversion, in order
to be able to distinguish plasma effects from true catalytic enhancement. |
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Wos |
000471670400116 |
Publication Date |
2019-05-08 |
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Edition |
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ISSN |
1385-8947 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.216 |
Times cited |
3 |
Open Access |
Not_Open_Access: Available from 05.05.2021
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Notes |
European Fund for Regional Development; FWOFWO, G.0254.14N ; University of Antwerp; FWO-FlandersFWO-Flanders, 11V8915N ; The authors acknowledge financial support from the European Fund for Regional Development through the cross-border collaborative Interreg V program Flanders-the Netherlands (project EnOp), the Fund for Scientific Research (FWO; Grant Number: G.0254.14N), a TOP-BOF project and an IOF-SBO (SynCO2Chem) project from the University of Antwerp. K. M. B. was funded as a PhD fellow (aspirant) of the FWOFlanders (Fund for Scientific Research-Flanders), Grant 11V8915N. |
Approved |
Most recent IF: 6.216 |
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Call Number |
PLASMANT @ plasmant @UA @ admin @ c:irua:159979 |
Serial |
5171 |
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Author |
Bogaerts, A. |
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Title |
Editorial Catalysts: Special Issue on Plasma Catalysis |
Type |
Editorial |
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Year |
2019 |
Publication |
Catalysts |
Abbreviated Journal |
Catalysts |
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Volume |
9 |
Issue |
2 |
Pages |
196 |
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Keywords |
Editorial; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma catalysis is gaining increasing interest for various gas conversion applications, such as CO2 conversion into value-added chemicals and fuels, N2 fixation for the synthesis of NH3 or NOx, and CH4 conversion into higher hydrocarbons or oxygenates [...] |
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000460702200090 |
Publication Date |
2019-02-21 |
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ISSN |
2073-4344 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.082 |
Times cited |
1 |
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.082 |
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| |
Call Number |
PLASMANT @ plasmant @UA @ admin @ c:irua:159153 |
Serial |
5166 |
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| Permanent link to this record |
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Author |
Bogaerts, A.; Zhang, Q.-Z.; Zhang, Y.-R.; Van Laer, K.; Wang, W. |
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Title |
Burning questions of plasma catalysis: Answers by modeling |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Catalysis today |
Abbreviated Journal |
Catal Today |
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| |
Volume |
337 |
Issue |
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Pages |
3-14 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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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. |
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Place of Publication |
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Language |
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Wos |
000482179500002 |
Publication Date |
2019-04-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0920-5861 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.636 |
Times cited |
7 |
Open Access |
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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 |
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| |
Call Number |
PLASMANT @ plasmant @c:irua:161775 |
Serial |
5356 |
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| Permanent link to this record |
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Author |
Bogaerts, A.; Yusupov, M.; Razzokov, J.; Van der Paal, J. |
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Title |
Plasma for cancer treatment: How can RONS penetrate through the cell membrane? Answers from computer modeling |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Frontiers of Chemical Science and Engineering |
Abbreviated Journal |
Front Chem Sci Eng |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma is gaining increasing interest for cancer
treatment, but the underlying mechanisms are not yet fully
understood. Using computer simulations at the molecular
level, we try to gain better insight in how plasma-generated
reactive oxygen and nitrogen species (RONS) can
penetrate through the cell membrane. Specifically, we
compare the permeability of various (hydrophilic and
hydrophobic) RONS across both oxidized and nonoxidized cell membranes. We also study pore formation,
and how it is hampered by higher concentrations of
cholesterol in the cell membrane, and we illustrate the
much higher permeability of H2O2 through aquaporin
channels. Both mechanisms may explain the selective
cytotoxic effect of plasma towards cancer cells. Finally, we
also discuss the synergistic effect of plasma-induced
oxidation and electric fields towards pore formation.
Keywords plasma medicine, cancer treatment, computer
modelling, cell membrane, reactive oxygen and nitrogen
species |
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Place of Publication |
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Wos |
000468848400004 |
Publication Date |
2019-03-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2095-0179 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.712 |
Times cited |
5 |
Open Access |
Not_Open_Access: Available from 23.05.2020
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Notes |
We acknowledge financial support from the Research Foundation–Flanders (FWO; Grant Nos. 1200216N and 11U5416N). The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. We are also very thankful to R. Cordeiro for the very interesting discussions. |
Approved |
Most recent IF: 1.712 |
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Call Number |
PLASMANT @ plasmant @UA @ admin @ c:irua:159977 |
Serial |
5172 |
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| Permanent link to this record |
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Author |
Rezaei, F.; Vanraes, P.; Nikiforov, A.; Morent, R.; De Geyter, N. |
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Title |
Applications of plasma-liquid systems : a review |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Materials |
Abbreviated Journal |
Materials |
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Volume |
12 |
Issue |
17 |
Pages |
2751 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma-liquid systems have attracted increasing attention in recent years, owing to their high potential in material processing and nanoscience, environmental remediation, sterilization, biomedicine, and food applications. Due to the multidisciplinary character of this scientific field and due to its broad range of established and promising applications, an updated overview is required, addressing the various applications of plasma-liquid systems till now. In the present review, after a brief historical introduction on this important research field, the authors aimed to bring together a wide range of applications of plasma-liquid systems, including nanomaterial processing, water analytical chemistry, water purification, plasma sterilization, plasma medicine, food preservation and agricultural processing, power transformers for high voltage switching, and polymer solution treatment. Although the general understanding of plasma-liquid interactions and their applications has grown significantly in recent decades, it is aimed here to give an updated overview on the possible applications of plasma-liquid systems. This review can be used as a guide for researchers from different fields to gain insight in the history and state-of-the-art of plasma-liquid interactions and to obtain an overview on the acquired knowledge in this field up to now. |
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Corporate Author |
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Wos |
000488880300104 |
Publication Date |
2019-08-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1996-1944 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.654 |
Times cited |
4 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.654 |
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Call Number |
UA @ admin @ c:irua:163805 |
Serial |
6285 |
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| Permanent link to this record |
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Author |
Heirman, P.; Van Boxem, W.; Bogaerts, A. |
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Title |
Reactivity and stability of plasma-generated oxygen and nitrogen species in buffered water solution: a computational study |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
21 |
Issue |
24 |
Pages |
12881-12894 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma-treated liquids have great potential for biomedical applications. However, insight into the underlying mechanisms and the exact chemistry is still scarce. In this study, we present the combination of a 0D chemical kinetics and a 2D fluid dynamics model to investigate the plasma treatment of a buffered water solution with the kINPen (R) plasma jet. Using this model, we calculated the gas and liquid flow profiles and the transport and chemistry of all species in the gas and the liquid phase. Moreover, we evaluated the stability of the reactive oxygen and nitrogen species after plasma treatment. We found that of all species, only H2O2, HNO2/NO2-, and HNO3/NO3- are stable in the buffered solution after plasma treatment. This is because both their production and loss processes in the liquid phase are dependent on short-lived radicals (e.g. OH, NO, and NO2). Apart from some discrepancy in the absolute values of the concentrations, which can be explained by the model, all general trends and observations in our model are in qualitative agreement with experimental data and literature. |
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Corporate Author |
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Place of Publication |
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Wos |
000472214000012 |
Publication Date |
2019-05-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
7 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.123 |
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Call Number |
UA @ admin @ c:irua:161314 |
Serial |
6320 |
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Author |
Tan, X.; Stephens, P.W.; Hendrickx, M.; Hadermann, J.; Segre, C.U.; Croft, M.; Kang, C.-J.; Deng, Z.; Lapidus, S.H.; Kim, S.W.; Jin, C.; Kotliar, G.; Greenblatt, M. |
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Title |
Tetragonal Cs1.17In0.81Cl3 : a charge-ordered indium halide perovskite derivative |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
31 |
Issue |
6 |
Pages |
1981-1989 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Polycrystalline samples of Cs1.17In0.81Cl3 were prepared by annealing a mixture of CsCl, InCl, and InCl3, stoichiometric for the targeted CsInCl3. Synchrotron powder X-ray diffraction refinement and chemical analysis by energy dispersive X-ray indicated that Cs1.17In0.81Cl3, a tetragonal distorted perovskite derivative (I4/m), is the thermodynamically stable product. The refined unit cell parameters and space group were confirmed by electron diffraction. In the tetragonal structure, In+ and In3+ are located in four different crystallographic sites, consistent with their corresponding bond lengths. In1, In2, and In3 are octahedrally coordinated, whereas In4 is at the center of a pentagonal bipyramid of Cl because of the noncooperative octahedral tilting of In4Cl6. The charged-ordered In+ and In3+ were also confirmed by X-ray absorption and Raman spectroscopy. Cs1.17In0.81Cl3 is the first example of an inorganic halide double perovskite derivative with charged-ordered In+ and In3+. Band structure and optical conductivity calculations were carried out with both generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ) approach; the GGA calculations estimated the band gap and optical band gap to be 2.27 eV and 2.4 eV, respectively. The large and indirect band gap suggests that Cs1.17In0.81Cl3 is not a good candidate for photovoltaic application. |
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Corporate Author |
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Place of Publication |
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Wos |
000462950400017 |
Publication Date |
2019-02-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
6 |
Open Access |
OpenAccess |
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Notes |
; M.G. and X.T. were supported by the Center for Computational Design of Functional Strongly Correlated Materials and Theoretical Spectroscopy under DOE Grant No. DE-FOA-0001276. M.G. also acknowledges support of NSF-DMR-1507252 grant. G.K. and C.-J.K. were supported by the Air Force Office of Scientific Research. MRCAT operations are supported by the Department of Energy and the MRCAT member institutions. The use of the Advanced Photon Source at the Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The works at IOPCAS were supported by NSF & MOST of China through research projects. ; |
Approved |
Most recent IF: 9.466 |
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Call Number |
UA @ admin @ c:irua:159413 |
Serial |
5262 |
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Author |
Ma, R.; He, Y.; Feng, J.; Hu, Z.-Y.; Van Tendeloo, G.; Li, D. |
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Title |
A facile synthesis of Ag@PdAg core-shell architecture for efficient purification of ethene feedstock |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Journal of catalysis |
Abbreviated Journal |
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Volume |
369 |
Issue |
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Pages |
440-449 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Precise control of elemental configurations within multimetallic nanoparticles could enable access to functional nanomaterials with significant performance benefits. Here, we present a one-pot synthesis of supported Ag@PdAg core-shell catalyst with an ordered PdAg alloy shell and an Ag core. Both the relative reduction potential and ratio of metal precursors are essential for this synthesis strategy. The distinguished properties of Ag@PdAg, particularly the electronic structure, indicates the existence of electron modification not only between Pd and Ag on PdAg shell, but between Ag core and alloy shell. The Ag@PdAg catalyst displays 97% ethene yield in the partial hydrogenation of acetylene, which is 2.0 and 8.1 times that of over PdAg alloy and pure Pd catalysts, and this is the most selective catalyst reported to data under industrial evaluation conditions. Moreover, this core-shell structure exhibits preferable stability with comparison to PdAg alloy catalyst. The facile synthesis of core-shell architecture with alloy shell structure provides a new platform for efficient catalytic transfer of chemical resource. (C) 2018 Elsevier Inc. All rights reserved. |
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Wos |
000460711700045 |
Publication Date |
2018-12-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-9517 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:181261 |
Serial |
6848 |
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Author |
Mobaraki, A.; Sevik, C.; Yapicioglu, H.; Cakir, D.; Gulseren, O. |
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Title |
Temperature-dependent phonon spectrum of transition metal dichalcogenides calculated from the spectral energy density: Lattice thermal conductivity as an application |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
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Volume |
100 |
Issue |
3 |
Pages |
035402 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Predicting the mechanical and thermal properties of quasi-two-dimensional (2D) transition metal dichalco-genides (TMDs) is an essential task necessary for their implementation in device applications. Although rigorous density-functional-theory-based calculations are able to predict mechanical and electronic properties, mostly they are limited to zero temperature. Classical molecular dynamics facilitates the investigation of temperature-dependent properties, but its performance highly depends on the potential used for defining interactions between the atoms. In this study, we calculated temperature-dependent phonon properties of single-layer TMDs, namely, MoS2, MoSe2, WS2, and WSe2, by utilizing Stillinger-Weber-type potentials with optimized sets of parameters with respect to the first-principles results. The phonon lifetimes and contribution of each phonon mode in thermal conductivities in these monolayer crystals are systematically investigated by means of the spectralenergy-density method based on molecular dynamics simulations. The obtained results from this approach are in good agreement with previously available results from the Green-Kubo method. Moreover, detailed analysis of lattice thermal conductivity, including temperature-dependent mode decomposition through the entire Brillouin zone, shed more light on the thermal properties of these 2D crystals. The LA and TA acoustic branches contribute most to the lattice thermal conductivity, while ZA mode contribution is less because of the quadratic dispersion around the Brillouin zone center, particularly in MoSe2 due to the phonon anharmonicity, evident from the redshift, especially in optical modes, by increasing temperature. For all the considered 2D crystals, the phonon lifetime values are compelled by transition metal atoms, whereas the group velocity spectrum is dictated by chalcogen atoms. Overall, the lattice thermal conductivity is linearly proportional with inverse temperature. |
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Wos |
000473536400003 |
Publication Date |
2019-07-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:193764 |
Serial |
8645 |
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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. |
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Title |
Azimuthal and radial flow patterns of 1g-Geldart B-type particles in a gas-solid vortex reactor |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Powder technology |
Abbreviated Journal |
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Volume |
354 |
Issue |
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Pages |
410-422 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Wos |
000490625500041 |
Publication Date |
2019-06-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0032-5910 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:162120 |
Serial |
7543 |
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| Permanent link to this record |
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Author |
Ramachandran, R.K.; Filez, M.; Solano, E.; Poelman, H.; Minjauw, M.M.; Van Daele, M.; Feng, J.-Y.; La Porta, A.; Altantzis, T.; Fonda, E.; Coati, A.; Garreau, Y.; Bals, S.; Marin, G.B.; Detavernier, C.; Dendooven, J. |
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Title |
Chemical and Structural Configuration of Pt Doped Metal Oxide Thin Films Prepared by Atomic Layer Deposition |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
31 |
Issue |
31 |
Pages |
9673-9683 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
Pt doped semiconducting metal oxides and Pt metal clusters embedded in an oxide matrix are of interest for applications such as catalysis and gas sensing, energy storage and memory devices. Accurate tuning of the dopant level is crucial for adjusting the properties of these materials. Here, a novel atomic layer deposition (ALD) based method for doping Pt into In2O3 in specific, and metals in metal oxides in general, is demonstrated. This approach combines alternating exposures of Pt and In2O3 ALD processes in a single ‘supercycle’, followed by supercycle repetition leading to multilayered nanocomposites. The atomic level control of ALD and its conformal nature make the method suitable for accurate dopant control even on high surface area supports. Oxidation state, local structural environment and crystalline phase of the embedded Pt dopants were obtained by means of X-ray characterization methods and high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In addition, this approach allows characterization of the nucleation stages of metal ALD processes, by stacking those states multiple times in an oxide matrix. Regardless of experimental conditions, a few Pt ALD cycles leads to the formation of oxidized Pt species due to their highly dispersed nature, as proven by X-ray absorption spectroscopy (XAS). Grazing-incidence small-angle X-ray scattering (GISAXS) and highresolution scanning transmission electron microscopy, combined with energy dispersive X-ray spectroscopy (HR-STEM/EDXS) show that Pt is evenly distributed in the In2O3 metal oxide matrix without the formation of clusters. For a larger number of Pt ALD
cycles, typ. > 10, the oxidation state gradually evolves towards fully metallic, and metallic Pt clusters are obtained within the In2O3 metal oxide matrix. This work reveals how tuning of the ALD supercycle approach for Pt doping allows controlled engineering of the Pt compositional and structural configuration within a metal oxide matrix. |
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Place of Publication |
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Language |
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Wos |
000502418000010 |
Publication Date |
2019-11-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
6 |
Open Access |
OpenAccess |
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Notes |
This research was supported by the Flemish Research Foundation (FWO-Vlaanderen), the Flemish Government (Long term structural funding – Methusalem funding and Medium scale research infrastructure funding-Hercules funding), the Special Research Fund BOF of Ghent University (GOA 01G01513) and the CALIPSO Trans National Access Program funded by the European Commission in supplying financing of travel costs. We are grateful to the SIXS and SAMBA-SOLEIL staff for smoothly running the beamline facilities. J.D. and R.K.R. are postdoctoral fellows of the FWO. |
Approved |
Most recent IF: 9.466 |
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Call Number |
EMAT @ emat @c:irua:164056 |
Serial |
5380 |
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| Permanent link to this record |
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Author |
Altantzis, T.; Lobato, I.; De Backer, A.; Béché, A.; Zhang, Y.; Basak, S.; Porcu, M.; Xu, Q.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Van Tendeloo, G.; Van Aert, S.; Bals, S. |
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Title |
Three-Dimensional Quantification of the Facet Evolution of Pt Nanoparticles in a Variable Gaseous Environment |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
|
| |
Volume |
19 |
Issue |
19 |
Pages |
477-481 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Pt nanoparticles play an essential role in a wide variety of catalytic reactions. The activity of the particles strongly depends on their three-dimensional (3D) structure and exposed facets, as well as on the reactive environment. High-resolution electron microscopy has often been used to characterize nanoparticle catalysts but unfortunately most observations so far have been either performed in vacuum and/or using conventional (2D) in situ microscopy. The latter however does not provide direct 3D morphological information. We have implemented a quantitative methodology to measure variations of the 3D atomic structure of nanoparticles under the flow of a selected gas. We were thereby able to quantify refaceting of Pt nanoparticles with atomic resolution during various oxidation−reduction cycles. In a H2 environment, a more faceted surface morphology of the particles was observed with {100} and {111} planes being dominant. On the other hand, in O2 the percentage of {100} and {111} facets decreased and a significant increase of higher order facets was found, resulting in a more rounded morphology. This methodology opens up new opportunities toward in situ characterization of catalytic nanoparticles because for the first time it enables one to directly measure 3D morphology variations at the atomic scale in a specific gaseous reaction environment. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000455561300061 |
Publication Date |
2019-01-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.712 |
Times cited |
82 |
Open Access |
OpenAccess |
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Notes |
This work was supported by the European Research Council (Grant 335078 COLOURATOM to S.B. and Grant 770887 PICOMETRICS to S.V.A.). The authors acknowledge funding from the European Commission Grant (EUSMI 731019 to S.B., L.M.L.-M., and Q.X. and MUMMERING 765604 to S.B. and Q.X.). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0368.15N, G.0369.15N, and G.0267.18N), postdoctoral grants to T.A. and A.D.B, and an FWO [PEGASUS]2 Marie Sklodowska-Curie fellowship to Y.Z. (12U4917N). L.M.L.-M. acknowledges funding from the Spanish Ministerio de Economía y Competitividad (Grant MAT2017-86659-R). We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan X Pascal GPU used for this research. ecas_sara Realnano 815128; sygma |
Approved |
Most recent IF: 12.712 |
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| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:156390 |
Serial |
5150 |
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| Permanent link to this record |
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Author |
Tunca, B.; Lapauw, T.; Delville, R.; Neuville, D.R.; Hennet, L.; Thiaudiere, D.; Ouisse, T.; Hadermann, J.; Vleugels, J.; Lambrinou, K. |
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Title |
Synthesis and Characterization of Double Solid Solution (Zr,Ti)(2)(Al,Sn)C MAX Phase Ceramics |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
58 |
Issue |
10 |
Pages |
6669-6683 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Quasi phase-pure (>98 wt %) MAX phase solid solution ceramics with the (ZryTi)(2)(Al-0.5,Sn-0.5)C stoichiometry and variable Zr/Ti ratios were synthesized by both reactive hot pressing and pressureless sintering of ZrH2, TiH2, Al, Sn, and C powder mixtures. The influence of the different processing parameters, such as applied pressure and sintering atmosphere, on phase purity and microstructure of the produced ceramics was investigated. The addition of Sn to the (Zr,Ti)(2)AlC system was the key to achieve phase purity. Its effect on the crystal structure of a 211-type MAX phase was assessed by calculating the distortions of the octahedral M6C and trigonal M(6)A prisms due to steric effects. The M(6)A prismatic distortion values were found to be smaller in Sn-containing double solid solutions than in the (Zr,Ti)(2)AlC MAX phases. The coefficients of thermal expansion along the < a > and < c > directions were measured by means of Rietveld refinement of high-temperature synchrotron X-ray diffraction data of (Zr1-x,Ti-x)(2)(Al-0.5,Sn-0.5)C MAX phase solid solutions with x = 0, 0.3, 0.7, and 1. The thermal expansion coefficient data of the Ti-2(Al-0.5,Sn-0.5)C solid solution were compared with those of the Ti2AlC and Ti2SnC ternary compounds. The thermal expansion anisotropy increased in the (Zr,Ti)(2)(Al-0.5,Sn-0.5)C double solid solution MAX phases as compared to the Zr-2(Al-0.5,Sn-0.5)C and Ti-2(Al-0.5,Sn-0.5)C end-members. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000469304700014 |
Publication Date |
2019-05-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
3 |
Open Access |
Not_Open_Access |
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Notes |
; H. Roussel and D. Pinek are acknowledged for the Ti<INF>2</INF>SnC single-crystal production and high-temperature XRD measurements performed at Grenoble INP-LMGP-CMTC. This research was funded partly by the European Atomic Energy Community's (Euratom) Seventh Framework Programme FP7/2007-2013 under Grant Agreement No. 604862 (FP7MatISSE), and partly by the Euratom research and training programme 2014-2018 under Grant Agreement No. 740415 (H2020 IL TROVATORE). T.L. thanks the Agency for Innovation by Science and Technology (IWT), Flanders, Belgium, for Ph.D. Grant No. 131081. B.T. acknowledges the financial support of the SCK.CEN Academy for Nuclear Science and Technology. All authors gratefully acknowledge Synchrotron SOLEIL for the allocated time at the DIFFABS beamline in association with Project 20161410 entitled “Investigation of (Zr-Ti)-Al-C MAX phases with in-situ high-temperature XRD” and the Hercules Foundation for Project AKUL/1319 (CombiS(T)EM). ; |
Approved |
Most recent IF: 4.857 |
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| |
Call Number |
UA @ admin @ c:irua:160318 |
Serial |
5261 |
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| Permanent link to this record |
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Author |
Pennycook, T.J.; Martinez, G.T.; Nellist, P.D.; Meyer, J.C. |
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Title |
High dose efficiency atomic resolution imaging via electron ptychography |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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| |
Volume |
196 |
Issue |
196 |
Pages |
131-135 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Radiation damage places a fundamental limitation on the ability of microscopy to resolve many types of materials at high resolution. Here we evaluate the dose efficiency of phase contrast imaging with electron ptychography. The method is found to be far more resilient to temporal incoherence than conventional and spherical aberration optimized phase contrast imaging, resulting in significantly greater clarity at a given dose. This robustness is explained by the presence of achromatic lines in the four dimensional ptychographic dataset. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000451180800018 |
Publication Date |
2018-10-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.843 |
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Call Number |
UA @ admin @ c:irua:165939 |
Serial |
6301 |
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Author |
Sirotina, A.P.; Callaert, C.; Volykhov, A.A.; Frolov, A.S.; Sanchez-Barriga, J.; Knop-Gericke, A.; Hadermann, J.; Yashina, L.V. |
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Title |
Mechanistic studies of gas reactions with multicomponent solids : what can we learn by combining NAP XPS and atomic resolution STEM/EDX? |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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| |
Volume |
123 |
Issue |
43 |
Pages |
26201-26210 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Rapid development of experimental techniques has enabled real time studies of solid gas reactions at the level reaching the atomic scale. In the present paper, we focus on a combination of atomic resolution STEM/EDX, which visualizes the reaction zone, and near ambient pressure (NAP) XPS, which collects information for a surface layer of variable thickness under reaction conditions. We compare the behavior of two affined topological insulators, Bi2Te3 and Sb2Te3. We used a simple reaction with molecular oxygen occurring at 298 K, which is of practical importance to avoid material degradation. Despite certain limitations, a combination of in situ XPS and ex situ cross-sectional STEM/EDX allowed us to obtain a self-consistent picture of the solid gas reaction mechanism for oxidation of Sb2Te3 and Bi2Te3 crystals, which includes component redistribution between the oxide and the subsurface layer and Te segregation with formation of a thin ordered layer at the interface. The process is multistep in case of both compounds. At the very beginning of the oxidation process the reactivity is determined by the energy benefit of the corresponding element oxygen bond formation. Further in the oxidation process, the behavior of these two compounds becomes similar and features component redistribution between the oxide and the subsurface layer. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000493865700019 |
Publication Date |
2019-10-03 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:164664 |
Serial |
6310 |
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| Permanent link to this record |
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Author |
Jin, L.; Batuk, M.; Kirschner, F.K.K.; Lang, F.; Blundell, S.J.; Hadermann, J.; Hayward, M.A. |
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Title |
Exsolution of SrO during the Topochemical Conversion of LaSr3CoRuO8to the Oxyhydride LaSr3CoRuO4H4 |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
58 |
Issue |
21 |
Pages |
14863-14870 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Reaction of the n = 1 Ruddlesden-Popper oxide LaSr3CoRuO8 with CaH2 yields the oxyhydride phase LaSr3CoRuO4H4 via topochemical anion-exchange. Close inspection of X-ray and neutron powder diffraction data in combination with HAADF-STEM images reveals that nanoparticles of SrO are exsolved from the system during the reaction, with the change in cation stoichiometry accommodated by the inclusion of n > 1 (Co/Ru)nOn+1H2n ‘perovskite’ layers into the Ruddlesden-Popper stacking sequence. This novel pseudo-topochemical process offers a new route for the formation of n > 1 Ruddlesden-Popper structured materials. Magnetization data are consistent with a LaSr3Co1+Ru2+O4H4 (Co1+, d8, S = 1; Ru2+, d6, S = 0) oxidation/spin state combination. Neutron diffraction and μ+SR data show no evidence for long-range magnetic order down to 2 K, suggesting the diamagnetic Ru2+ centers impede the Co-Co magnetic exchange interactions. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000494894400062 |
Publication Date |
2019-11-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
1 |
Open Access |
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Notes |
We thank P. Manuel for assistance collecting the neutron powder diffraction data. We thank The Leverhulme Trust grant award RPG-2014-366 “Topochemical reduction of 4d and 5d transition metal oxides” for supporting this work. Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Investigation by TEM was supported through the FWO grant G035619N. |
Approved |
Most recent IF: 4.857 |
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| |
Call Number |
EMAT @ emat @c:irua:164625 |
Serial |
5434 |
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Author |
Khalili, M.; Daniels, L.; Lin, A.; Krebs, F.C.; Snook, A.E.; Bekeschus, S.; Bownel, W.B.; Miller, V. |
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Title |
Non-thermal plasma-induced immunogenic cell death in cancer |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
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Volume |
52 |
Issue |
42 |
Pages |
423001 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Recent advances in biomedical research in cancer immunotherapy have identified the use of an oxidative stress-based approach to treat cancers, which works by inducing immunogenic cell death (ICD) in cancer cells. Since the anti-cancer effects of non-thermal plasma (NTP) are largely attributed to the reactive oxygen and nitrogen species that are delivered to and generated inside the target cancer cells, it is reasonable to postulate that NTP would be an effective modality for ICD induction. NTP treatment of tumors has been shown to destroy cancer cells rapidly and, under specific treatment regimens, this leads to systemic tumorspecific immunity. The translational benefit of NTP for treatment of cancer relies on its ability to enhance the interactions between NTP-exposed minor cells and local immune cells which initiates subsequent protective immune responses. This review discusses results from recent investigations of NTP application to induce ICD in cancer cells. With further optimization of clinical devices and treatment protocols, NTP can become an essential part of the therapeutic armament against cancer. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000479103100001 |
Publication Date |
2019-07-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
0022-3727 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.588 |
Times cited |
6 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.588 |
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Call Number |
UA @ admin @ c:irua:161774 |
Serial |
6313 |
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Author |
Marteleur, M.; Idrissi, H.; Amin-Ahmadi, B.; Prima, F.; Schryvers, D.; Jacques, P.J. |
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Title |
On the nucleation mechanism of {112} < 111 > mechanical twins in as-quenched beta metastable Ti-12 wt.% Mo alloy |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Materialia |
Abbreviated Journal |
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Volume |
7 |
Issue |
|
Pages |
Unsp 100418 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Recently developed beta-metastable Ti grades take advantage of the simultaneous activation of TRIP and TWIP effects for enhancing their work hardening rate. However, the role of each plasticity mechanism on the macroscopic mechanical response is still unclear. In this work, the nucleation mechanism of the first activated plasticity mechanism, namely {112} < 111 > twinning, was investigated. Firstly, post-mortem TEM analysis showed that twins nucleate on pre-existing microstructural defects such as thermal jogs with the zonal dislocation mechanism. The precipitation of the omega phase on twin boundaries has been observed, as well as the emission of numerous dislocations from super-jogs present in these twin boundaries. It is also shown that {112} < 111 > twins act as effective dislocation sources for the subsequent plasticity mechanisms such as beta -> alpha '' martensitic transformation and {332} < 111 > twinning. Secondly, in situ TEM tensile testing of the investigated Ti grade highlighted the primary role of the initial defect configuration present in the microstructure. It is shown that twins cannot nucleate without the presence of specific defects allowing the triggering of the dislocation decomposition needed for the twinning mechanism highlighted in investigated bulk samples. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000537131000052 |
Publication Date |
2019-07-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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ISSN |
2589-1529 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
|
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:170326 |
Serial |
6875 |
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Author |
Fatermans, J.; Van Aert, S.; den Dekker, A.J. |
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Title |
The maximum a posteriori probability rule for atom column detection from HAADF STEM images |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
201 |
Issue |
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Pages |
81-91 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
Recently, the maximum a posteriori (MAP) probability rule has been proposed as an objective and quantitative method to detect atom columns and even single atoms from high-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images. The method combines statistical parameter estimation and model-order selection using a Bayesian framework and has been shown to be especially useful for the analysis of the structure of beam-sensitive nanomaterials. In order to avoid beam damage, images of such materials are usually acquired using a limited incoming electron dose resulting in a low contrast-to-noise ratio (CNR) which makes visual inspection unreliable. This creates a need for an objective and quantitative approach. The present paper describes the methodology of the MAP probability rule, gives its step-by-step derivation and discusses its algorithmic implementation for atom column detection. In addition, simulation results are presented showing that the performance of the MAP probability rule to detect the correct number of atomic columns from HAADF STEM images is superior to that of other model-order selection criteria, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Moreover, the MAP probability rule is used as a tool to evaluate the relation between STEM image quality measures and atom detectability resulting in the introduction of the so-called integrated CNR (ICNR) as a new image quality measure that better correlates with atom detectability than conventional measures such as signal-to-noise ratio (SNR) and CNR. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000466343800009 |
Publication Date |
2019-02-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
OpenAccess |
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| |
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (No. W.O.010.16N, No. G.0368.15N, No. G.0502.18N). This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant Agreement No. 770887). |
Approved |
Most recent IF: 2.843 |
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| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:157176 |
Serial |
5153 |
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| Permanent link to this record |
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Author |
Wang, J.; Shin, Y.; Gauquelin, N.; Yang, Y.; Lee, C.; Jannis, D.; Verbeeck, J.; Rondinelli, J.M.; May, S.J. |
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Title |
Physical properties of epitaxial SrMnO2.5−δFγoxyfluoride films |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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| |
Volume |
31 |
Issue |
36 |
Pages |
365602 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Recently, topotactic fluorination has become an alternative way of doping epitaxial perovskite oxides through anion substitution to engineer their electronic properties instead of the more commonly used cation substitution. In this work, epitaxial oxyfluoride SrMnO2.5−δ F γ films were synthesized via topotactic fluorination of SrMnO2.5 films using polytetrafluoroethylene as the fluorine source. Oxidized SrMnO3 films were also prepared for comparison with the fluorinated samples. The F content, probed by x-ray photoemission spectroscopy, was systematically controlled by adjusting fluorination conditions. Electronic transport measurements reveal that increased F content (up to γ = 0.14) systematically increases the electrical resistivity, despite the nominal electron-doping induced by F substitution for O in these films. In contrast, oxidized SrMnO3 exhibits a decreased resistivity and conduction activation energy. A blue-shift of optical absorption features occurs with increasing F content. Density functional theory calculations indicate that F acts as a scattering center for electronic transport, controls the observed weak ferromagnetic behavior of the films, and reduces the inter-band optical transitions in the manganite films. These results stand in contrast to bulk electron-doped La1−x Ce x MnO3, illustrating how aliovalent anionic substitutions can yield physical behavior distinct from A-site substituted perovskites with the same nominal B-site oxidation states. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000472232000002 |
Publication Date |
2019-09-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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| |
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.649 |
Times cited |
5 |
Open Access |
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Notes |
Work at Drexel was supported by the National Science Foundation (NSF), grant number CMMI-1562223. Thin film synthesis utilized deposition instrumentation acquired through an Army Research Office DURIP grant (W911NF-14-1-0493). Y.S and J.M.R. were supported by NSF (Grant No. DMR-1454688). Calculations were performed using the QUEST HPC Facility at Northwestern, the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by NSF Grant No. ACI-1053575, and the Center for Nanoscale Materials (Carbon Cluster). Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. J.V. and N. G. acknowledge funding from a GOA project “Solarpaint” of the University of Antwerp. D.J. acknowledges funding from FWO project G093417N from the Flemish fund for scientific research. |
Approved |
Most recent IF: 2.649 |
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Call Number |
EMAT @ emat @UA @ admin @ c:irua:161174 |
Serial |
5293 |
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| Permanent link to this record |
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Author |
Magnus, W.; Brosens, F. |
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Title |
Occupation numbers in a quantum canonical ensemble : a projection operator approach |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physica: A : theoretical and statistical physics |
Abbreviated Journal |
Physica A |
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| |
Volume |
518 |
Issue |
518 |
Pages |
253-264 |
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Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
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Abstract |
Recently, we have used a projection operator to fix the number of particles in a second quantization approach in order to deal with the canonical ensemble. Having been applied earlier to handle various problems in nuclear physics that involve fixed particle numbers, the projector formalism was extended to grant access as well to quantum-statistical averages in condensed matter physics, such as particle densities and correlation functions. In this light, the occupation numbers of the subsequent single-particle energy eigenstates are key quantities to be examined. The goal of this paper is (1) to provide a sound extension of the projector formalism directly addressing the occupation numbers as well as the chemical potential, and (2) to demonstrate how the emerging problems related to numerical instability for fermions can be resolved to obtain the canonical statistical quantities for both fermions and bosons. (C) 2018 Elsevier B.V. All rights reserved. |
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Wos |
000456359200021 |
Publication Date |
2018-11-28 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0378-4371 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.243 |
Times cited |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.243 |
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Call Number |
UA @ admin @ c:irua:157468 |
Serial |
5223 |
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| Permanent link to this record |
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Author |
Lozano, D.P.; Couet, S.; Petermann, C.; Hamoir, G.; Jochum, J.K.; Picot, T.; Menendez, E.; Houben, K.; Joly, V.; Antohe, V.A.; Hu, M.Y.; Leu, B.M.; Alatas, A.; Said, A.H.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Piraux, L.; Van de Vondel, J.; Vantomme, A.; Temst, K.; Van Bael, M.J. |
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Title |
Experimental observation of electron-phonon coupling enhancement in Sn nanowires caused by phonon confinement effects |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
99 |
Issue |
6 |
Pages |
064512 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Reducing the size of a superconductor below its characteristic length scales can either enhance or suppress its critical temperature (T-c). Depending on the bulk value of the electron-phonon coupling strength, electronic and phonon confinement effects will play different roles in the modification of T-c. Experimentally disentangling each contribution has remained a challenge. We have measured both the phonon density of states and T-c of Sn nanowires with diameters of 18, 35, and 100 nm in order to quantify the effects of phonon confinement on superconductivity. We observe a shift of the phonon frequency towards the low-energy region and an increase in the electron-phonon coupling constant that can account for the measured increase in T-c. |
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Wos |
000459322400005 |
Publication Date |
2019-02-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
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Notes |
; We would like to thanks Jeroen Scheerder and Wout Keijers for their help and assistance during the low-temperature measurements. This work was supported by the Research Foundation Flanders (FWO), the Concerted Research Action (GOA/14/ 007), the Federation Wallonie-Bruxelles (ARC 13/18-052, Supracryst) and the Fonds de la Recherche Scientifique -FNRS under Grant No. T.0006.16. The authors acknowledge Hercules Stichting (Project Nos. AKUL/13/19 and AKUL/13/25). D.P.L. thanks the FWO for financial support. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:158621 |
Serial |
5212 |
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Author |
Zhao, L.; Macias, J.G.S.; Ding, L.; Idrissi, H.; Simar, A. |
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Title |
Damage mechanisms in selective laser melted AlSi10Mg under as built and different post-treatment conditions |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Microstructure And Processing |
Abbreviated Journal |
Mat Sci Eng A-Struct |
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Volume |
764 |
Issue |
764 |
Pages |
138210 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Selective laser melting (SLM) manufactured AlSi10Mg alloys present a fine silicon-rich network and precipitates which grant high mechanical strength but low ductility. Post-treatments, aiming at eliminating inherent defects related to SLM such as residual stresses, porosity or inhomogeneity, result in significant changes in the microstructure and impact both the hardening and the damage mechanisms of the post-treated material. The present work is dedicated to the investigation of the fracture of SLM AlSi10Mg under as built and three post-treatment conditions, namely two stress relieve heat treatments and friction stir processing (FSP). It is found that the interconnected Si network fosters damage at low strain due to the brittleness of the Si phase. The onset of damage transfers load to the enclosed Al phase which then fractures quickly under high stress, thus leading to low material ductility. In contrast, when the Si network is globularized into Si particles, the ductility is highly increased even in the case where the porosity and inhomogeneity of the microstructure remain after the post-treatment. The ductility enhancement results from the delay in void nucleation on the Si particles as well as from the tolerance for void growth in the Al matrix. |
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Place of Publication |
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Wos |
000486360100029 |
Publication Date |
2019-07-27 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0921-5093 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.094 |
Times cited |
1 |
Open Access |
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Notes |
; This research work has been supported by the WALInnov LongLifeAM project, Convention n 1810016, funded by Service public de Wallonie Economic Emploi Recherche (SPW-EER). L. Ding and A. Simar acknowledge the financial support of the European Research Council (ERC) for the Starting Grant ALUFIX project (grant agreement n 716678). J. G. Santos Macias acknowledges the support of the Fonds de la recherche scientifique -FNRS (FRIA grant), Belgium. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSRFNRS). Any-Shape is acknowledged for material supply. We thank Prof. P. J. Jacques from UCLouvain for fruitful discussion and critical reading of the paper. ; |
Approved |
Most recent IF: 3.094 |
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Call Number |
UA @ admin @ c:irua:162800 |
Serial |
5386 |
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| Permanent link to this record |
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Author |
Wang, L.; Wen, D.-Q.; Zhang, Q.-Z.; Song, Y.-H.; Zhang, Y.-R.; Wang, Y.-N. |
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Title |
Disruption of self-organized striated structure induced by secondary electron emission in capacitive oxygen discharges |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
28 |
Issue |
5 |
Pages |
055007 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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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. |
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Place of Publication |
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Wos |
000467827800001 |
Publication Date |
2019-04-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0963-0252 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
2 |
Open Access |
Not_Open_Access: Available from 13.05.2020
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Notes |
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Approved |
Most recent IF: 3.302 |
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Call Number |
UA @ admin @ c:irua:160365 |
Serial |
5270 |
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| Permanent link to this record |
