| Records |
| Author |
Zhao, Z.X.; Ma, X.; Cao, S.; Li, Y.Y.; Zeng, C.Y.; Wang, D.X.; Yao, X.; Deng, Z.J.; Zhang, X.P. |
| Title |
Identification of nano-width variants in a fully monoclinic martensitic Ni50Ti50 alloy by scanning electron microscope-based transmission Kikuchi diffraction and improved groupoid structure approach |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Materials Letters |
Abbreviated Journal |
Mater Lett |
| Volume |
281 |
Issue |
|
Pages |
128624 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Nano-width martensite plates in a fully martensitic Ni50Ti50 alloy are indexed successfully by using the off-axis transmission Kikuchi diffraction in scanning electron microscope (i.e., SEM-based TKD). The data obtained by SEM-TKD are effectively interpreted using an improved approach based on the framework of the theoretical groupoid structure method, where the equivalent variants transformed from the monoclinic variants are introduced to calculate all theoretical axis/angle pairs of rotation, and to formulate a complete list of source martensite to target martensite pairs. Consequently, B19' monoclinic martensite variants in NiTi alloys are identified unambiguously, by using numerical comparison between the experimental and theoretical rotation components, without the reference of retained parent phase. (C) 2020 Elsevier B.V. All rights reserved. |
| 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 |
000581134200033 |
Publication Date |
2020-09-07 |
| 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 |
0167-577x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor  |
3 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
; This work was supported by National Natural Science Foundation of China under Grant Nos. 51571092 and 51401081, and Guangdong Provincial Natural Science Foundation under Grant Nos. 2018B0303110012 and 2017A030313323. ; |
Approved |
Most recent IF: 3; 2020 IF: 2.572 |
| Call Number |
UA @ admin @ c:irua:173509 |
Serial |
6540 |
| Permanent link to this record |
| |
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| |
| Author |
Bafekry, A.; Stampfl, C.; Shayesteh, S.F. |
| Title |
A first-principles study of C3N nanostructures : control and engineering of the electronic and magnetic properties of nanosheets, tubes and ribbons |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Chemphyschem |
Abbreviated Journal |
Chemphyschem |
| Volume |
21 |
Issue |
2 |
Pages |
164-174 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using first-principles calculations we systematically investigate the atomic, electronic and magnetic properties of novel two-dimensional materials (2DM) with a stoichiometry C3N which has recently been synthesized. We investigate how the number of layers affect the electronic properties by considering monolayer, bilayer and trilayer structures, with different stacking of the layers. We find that a transition from semiconducting to metallic character occurs which could offer potential applications in future nanoelectronic devices. We also study the affect of width of C3N nanoribbons, as well as the radius and length of C3N nanotubes, on the atomic, electronic and magnetic properties. Our results show that these properties can be modified depending on these dimensions, and depend markedly on the nature of the edge states. Functionalization of the nanostructures by the adsorption of H adatoms is found induce metallic, half-metallic, semiconducting and ferromagnetic behavior, which offers an approach to tailor the properties, as can the application of strain. Our calculations give insight into this new family of C3N nanostructures, which reveal unusual electronic and magnetic properties, and may have great potential in applications such as sensors, electronics and optoelectronic at the nanoscale. |
| 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 |
000503453100001 |
Publication Date |
2019-11-09 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1439-4235 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.9 |
Times cited |
27 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 2.9; 2020 IF: 3.075 |
| Call Number |
UA @ admin @ c:irua:165045 |
Serial |
6282 |
| Permanent link to this record |
| |
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| |
| Author |
Pacquets, L.; Irtem, E.; Neukermans, S.; Daems, N.; Bals, S.; Breugelmans, T. |
| Title |
Size-controlled electrodeposition of Cu nanoparticles on gas diffusion electrodes in methanesulfonic acid solution |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Applied Electrochemistry |
Abbreviated Journal |
J Appl Electrochem |
| Volume |
51 |
Issue |
2 |
Pages |
|
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
| Abstract |
In this paper electrodeposition is used to obtain Cu nanoparticles, as it allows good control over particle size and distribution. These Cu particles were deposited onto a gas diffusion electrode which increased the resulting surface area. Prior to deposition, the surface was pre-treated with NaOH, HNO3, MQ and TX100 to investigate the influence on the electrodeposition of Cu on the gas diffusion electrode (GDE). When using HNO3, the smallest particles with the most homogeneous distribution and high particle roughness were obtained. Once the optimal substrate was determined, we further demonstrated that by altering the electrodeposition parameters, the particle size and density could be tuned. On the one hand, increasing the nucleation potential led to a higher particle density resulting in smaller particles because of an increased competition between particles. Finally, the Cu particle size increased when applying a greater growth charge and growth potential. This fundamental study thus opens up a path towards the synthesis of supported Cu materials with increased surface areas, which is interesting from a catalytic point of view. Larger surface areas are generally correlated with a better catalyst performance and thus higher product yields. This research can contributed in obtaining new insides into the deposition of metallic nanoparticles on rough surfaces. [GRAPHICS] . |
| 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 |
000568651000001 |
Publication Date |
2020-09-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-891x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.9 |
Times cited |
3 |
Open Access |
OpenAccess |
| Notes |
; L. Pacquets was supported through a PhD fellowship strategic basic research (1S56918N) of the Research Foundation-Flanders (FWO). N. Daems was supported through a postdoctoral fellowship (12Y3919N-ND) of the Research Foundation-Flanders (FWO). S. Neukermans was supported through an FWO project grant (G093317N). This research was financed by the research counsel of the university of Antwerp (BOF-GOA 33928). The authors recognize the contribution of Thomas Kenis for analytical validation and methodology. ; |
Approved |
Most recent IF: 2.9; 2020 IF: 2.235 |
| Call Number |
UA @ admin @ c:irua:171588 |
Serial |
6603 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, J.; Nguyen, M.D.; Gauquelin, N.; Verbeeck, J.; Do, M.T.; Koster, G.; Rijnders, G.; Houwman, E. |
| Title |
On the importance of the work function and electron carrier density of oxide electrodes for the functional properties of ferroelectric capacitors |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physica Status Solidi-Rapid Research Letters |
Abbreviated Journal |
Phys Status Solidi-R |
| Volume |
14 |
Issue |
14 |
Pages |
1900520 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
It is important to understand the effect of the interfaces between the oxide electrode layers and the ferroelectric layer on the polarization response for optimizing the device performance of all-oxide ferroelectric devices. Herein, the effects of the oxide La0.07Ba0.93SnO3 (LBSO) as an electrode material in an PbZr0.52Ti0.48O3 (PZT) ferroelectric capacitor are compared with those of the more commonly used SrRuO3 (SRO) electrode. SRO (top)/PZT/SRO (bottom), SRO/PZT/LBSO, and SRO/PZT/2 nm SRO/LBSO devices are fabricated. Only marginal differences in crystalline properties, determined by X-ray diffraction and scanning transmission electron microscopy, are found. High-quality polarization loops are obtained, but with a much larger coercive field for the SRO/PZT/LBSO device. In contrast to the SRO/PZT/SRO device, the polarization decreases strongly with increasing field cycling. This fatigue problem can be remedied by inserting a 2 nm SRO layer between PZT and LBSO. It is argued that strongly increased charge injection into the PZT occurs at the bottom interface, because of the low PZT/LBSO interfacial barrier and the much lower carrier density in LBSO, as compared with that in SRO, causing a low dielectric constant, depleted layer in LBSO. The charge injection creates a trapped space charge in the PZT, causing the difference in fatigue behavior. |
| 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 |
000506195600001 |
Publication Date |
2019-12-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1862-6254 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.8 |
Times cited |
6 |
Open Access |
OpenAccess |
| Notes |
; This work was supported by Nederlandse Organisatie voor Wetenschappelijk Onderzoek through grant no.13HTSM01. ; |
Approved |
Most recent IF: 2.8; 2020 IF: 3.032 |
| Call Number |
UA @ admin @ c:irua:165681 |
Serial |
6316 |
| Permanent link to this record |
| |
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| |
| Author |
Nord, M.; Webster, R.W.H.; Paton, K.A.; McVitie, S.; McGrouther, D.; MacLaren, I.; Paterson, G.W. |
| Title |
Fast pixelated detectors in scanning transmission electron microscopy. Part I: data acquisition, live processing, and storage |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Microscopy And Microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
26 |
Issue |
4 |
Pages |
Pii S1431927620001713-666 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The use of fast pixelated detectors and direct electron detection technology is revolutionizing many aspects of scanning transmission electron microscopy (STEM). The widespread adoption of these new technologies is impeded by the technical challenges associated with them. These include issues related to hardware control, and the acquisition, real-time processing and visualization, and storage of data from such detectors. We discuss these problems and present software solutions for them, with a view to making the benefits of new detectors in the context of STEM more accessible. Throughout, we provide examples of the application of the technologies presented, using data from a Medipix3 direct electron detector. Most of our software are available under an open source licence, permitting transparency of the implemented algorithms, and allowing the community to freely use and further improve upon them. |
| 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 |
000555537900004 |
Publication Date |
2020-07-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1431-9276 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.8 |
Times cited |
4 |
Open Access |
OpenAccess |
| Notes |
; The performance of this work was mainly supported by the Engineering and Physical Sciences Research Council (EPSRC) of the UK via the project “Fast Pixel Detectors: a paradigm shift in STEM imaging” (grant no. EP/M009963/1). G.W.P. received additional support from the EPSRC under grant no. EP/M024423/1. M.N. received additional support for this work from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 838001. The studentship of R.W.H.W. was supported by the EPSRC Doctoral Training Partnership grant no. EP/N509668/1. S.McV. was supported by EPSRC grant no. EP/M024423/1. I.M. was supported by EPSRC grant no. EP/M009963/1. The studentship of K.A.P. was funded entirely by the UK Science and Technology Facilities Council (STFC) Industrial CASE studentship “Next2 TEM Detection” (no. ST/P002471/1) with Quantum Detectors Ltd. as the industrial partner. D.McG. was also supported by EPSRC grant no. EP/M009963/1. As an inventor of intellectual property related to the MERLIN detector hardware, he is a beneficiary of the license agreement between the University of Glasgow and Quantum Detectors Ltd. The development of the integration of TopSpin with the Merlin readout of the Medipix3 camera has been performed with the aid of financial assistance from the EPSRC under grant no. EP/R511705/1 and through direct collaboration between NanoMEGAS and Quantum Detectors Ltd. ; |
Approved |
Most recent IF: 2.8; 2020 IF: 1.891 |
| Call Number |
UA @ admin @ c:irua:171185 |
Serial |
6518 |
| Permanent link to this record |
| |
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| |
| Author |
Paterson, G.W.; Webster, R.W.H.; Ross, A.; Paton, K.A.; Macgregor, T.A.; McGrouther, D.; MacLaren, I.; Nord, M. |
| Title |
Fast pixelated detectors in scanning transmission electron microscopy. part II : post-acquisition data processing, visualization, and structural characterization |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Microscopy And Microanalysis |
Abbreviated Journal |
Microsc Microanal |
| Volume |
26 |
Issue |
5 |
Pages |
944-963 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Fast pixelated detectors incorporating direct electron detection (DED) technology are increasingly being regarded as universal detectors for scanning transmission electron microscopy (STEM), capable of imaging under multiple modes of operation. However, several issues remain around the post-acquisition processing and visualization of the often very large multidimensional STEM datasets produced by them. We discuss these issues and present open source software libraries to enable efficient processing and visualization of such datasets. Throughout, we provide examples of the analysis methodologies presented, utilizing data from a 256 x 256 pixel Medipix3 hybrid DED detector, with a particular focus on the STEM characterization of the structural properties of materials. These include the techniques of virtual detector imaging; higher-order Laue zone analysis; nanobeam electron diffraction; and scanning precession electron diffraction. In the latter, we demonstrate a nanoscale lattice parameter mapping with a fractional precision <= 6 x 10(-4) (0.06%). |
| 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 |
000576859800011 |
Publication Date |
2020-09-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
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| ISSN |
1431-9276 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.8 |
Times cited |
3 |
Open Access |
OpenAccess |
| Notes |
; G.W.P. and M.N. were the principal authors of the fpd and pixStem libraries reported herein (details of all contributions are documented in the repositories) and have made all of these available under open source licence GPLv3 for the benefit of the community. R.W.H.W., A.R., and K.A.P. have also made contributions to the source codes in these libraries. G.W.P and M.N. have led the data acquisition and analysis, and the drafting of this manuscript. The performance of this work was mainly supported by Engineering and Physical Sciences Research Council (EPSRC) of the UK via the project “Fast Pixel Detectors: a paradigm shift in STEM imaging” (Grant No. EP/M009963/1). G.W.P. received additional support from the EPSRC under Grant No. EP/M024423/1. M.N. received additional support for this work from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 838001. R.W.H.W., A.R., K.A.P., T.A.M., D.McG., and I.M. have all contributed either through acquisition and analysis of data or through participation in the revision of the manuscript. The studentships of R.W.H.W. and T.A.M. were supported by the EPSRC Doctoral Training Partnership Grant No. EP/N509668/1. I.M. and D.McG. were supported by EPSRC Grant No. EP/M009963/1. The studentship of K.A.P. was funded entirely by the UK Science and Technology Facilities Council (STFC) Industrial CASE studentship “Next2 TEM Detection” (No. ST/ P002471/1) with Quantum Detectors Ltd. as the industrial partner. As an inventor of intellectual property related to the MERLIN detector hardware, D.McG. is a beneficiary of the license agreement between the University of Glasgow and Quantum Detectors Ltd. We thank Diamond Quantum Detectors Ltd. for Medipix3 detector support; Dr. Bruno Humbel from Okinawa Institute of Science and Technology; and Dr. Caroline Kizilyaprak from the University of Lausanne for providing the liver sample; Dr. Ingrid Hallsteinsen and Prof. Thomas Tybell from the Norwegian University of Science and Technology (NTNU) for providing the La0.7Sr0.3MnO3/LaFeO3/SrTiO3 sample shown in Figure 4; and NanoMEGAS for the loan of the DigiSTAR precession system and TopSpin acquisition software. The development of the integration of TopSpin with the Merlin readout of the Medipix3 camera has been performed with the aid of financial assistance from the EPSRC under Grant No. EP/R511705/1 and through direct collaboration between NanoMEGAS and Quantum Detectors Ltd. ; |
Approved |
Most recent IF: 2.8; 2020 IF: 1.891 |
| Call Number |
UA @ admin @ c:irua:172695 |
Serial |
6519 |
| Permanent link to this record |
| |
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| |
| Author |
Clima, S.; Garbin, D.; Opsomer, K.; Avasarala, N.S.; Devulder, W.; Shlyakhov, I.; Keukelier, J.; Donadio, G.L.; Witters, T.; Kundu, S.; Govoreanu, B.; Goux, L.; Detavernier, C.; Afanas'ev, V.; Kar, G.S.; Pourtois, G. |
| Title |
Ovonic threshold-switching GexSey chalcogenide materials : stoichiometry, trap nature, and material relaxation from first principles |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physica Status Solidi-Rapid Research Letters |
Abbreviated Journal |
Phys Status Solidi-R |
| Volume |
|
Issue |
|
Pages |
1900672 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Density functional theory simulations are used to identify the structural factors that define the material properties of ovonic threshold switches (OTS). They show that the nature of mobility-gap trap states in amorphous Ge-rich Ge50Se50 is related to Ge-Ge bonds, whereas in Se-rich Ge30Se70 the Ge valence-alternating-pairs and Se lone-pairs dominate. To obtain a faithful description of the electronic structure and delocalization of states, it is required to combine hybrid exchange-correlation functionals with large unit-cell models. The extent of localization of electronic states depends on the applied external electric field. Hence, OTS materials undergo structural changes during electrical cycling of the device, with a decrease in the population of less exothermic Ge-Ge bonds in favor of more exothermic Ge-Se. This reduces the amount of charge traps, which translates into coordination changes, an increase in mobility-gap, and subsequently changes in the selector-device electrical parameters. The threshold voltage drift process can be explained by natural evolution of the nonpreferred Ge-Ge bonds (or “chains”/clusters thereof) in Ge-rich GexSe1-x. The effect of extrinsic doping is shown for Si and N, which introduce strong covalent bonds into the system, increase both mobility-gap and crystallization temperature, and decrease the leakage current. |
| 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 |
000512431100001 |
Publication Date |
2020-01-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1862-6254 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.8 |
Times cited |
3 |
Open Access |
|
| Notes |
; This work was carried out in the framework of the imec Core CMOS-Emerging Memory Program. Financial support from EU H2020-NMBPTO-IND-2018 project “INTERSECT” (Grant No. 814487) is acknowledged. ; |
Approved |
Most recent IF: 2.8; 2020 IF: 3.032 |
| Call Number |
UA @ admin @ c:irua:166492 |
Serial |
6575 |
| Permanent link to this record |
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| |
| Author |
Ozcan, M.; Ozen, S.; Yagmurcukardes, M.; Sahin, H. |
| Title |
Structural, electronic and vibrational properties of ultra-thin octahedrally coordinated structure of EuO2 |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Magnetism And Magnetic Materials |
Abbreviated Journal |
J Magn Magn Mater |
| Volume |
493 |
Issue |
493 |
Pages |
165668 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Novel stable ultra-thin phases of europium oxide are investigated by means of state-of-the-art first principles calculations. Total energy calculations show that single layers of EuO2 and Eu(OH)(2) can be stabilized in an octahedrally coordinated (1T) atomic structure. However, phonon calculations reveal that although both structures are energetically feasible, only the 1T-EuO2 phase has dynamical stability. The phonon spectrum of 1T-EuO2 displays three Raman active modes; a non-degenerate out-of-plane A(1g) mode at 353.5 cm(-1) and two doubly-degenerate in-plane E-g modes at 304.3 cm(-1). Furthermore, magnetic ground state and electronic band dispersion calculations show that the single layer EuO2 is a metal with net magnetic moment of 5(mu B) per unitcell resulting in a half-metallic ferrimagnetic behavior. Moreover, robustness of the half-metallic ferrimagnetic characteristics of EuO2 is confirmed by the application of electric field and charging. Single layer 1T-EuO2, with its stable ultra-thin structure and half-metallic ferrimagnetic feature, is a promising novel material for nanoscale electronic and spintronic applications. |
| 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 |
000486397800003 |
Publication Date |
2019-08-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-8853 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
1 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS acknowledges financial support from the TUBITAK under the project number 117F095. MY is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship. ; |
Approved |
Most recent IF: 2.7; 2020 IF: 2.63 |
| Call Number |
UA @ admin @ c:irua:162755 |
Serial |
6323 |
| Permanent link to this record |
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| |
| Author |
Gonzalez-Garcia, A.; Lopez-Perez, W.; Gonzalez-Hernandez, R.; Rivera-Julio, J.; Espejo, C.; Milošević, M.V.; Peeters, F.M. |
| Title |
Two-dimensional hydrogenated buckled gallium arsenide: an ab initio study |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
32 |
Issue |
14 |
Pages |
145502 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
First-principles calculations have been carried out to investigate the stability, structural and electronic properties of two-dimensional (2D) hydrogenated GaAs with three possible geometries: chair, zigzag-line and boat configurations. The effect of van der Waals interactions on 2D H-GaAs systems has also been studied. These configurations were found to be energetic and dynamic stable, as well as having a semiconducting character. Although 2D GaAs adsorbed with H tends to form a zigzag-line configuration, the energy differences between chair, zigzag-line and boat are very small which implies the metastability of the system. Chair and boat configurations display a – direct bandgap nature, while pristine 2D-GaAs and zigzag-line are indirect semiconductors. The bandgap sizes of all configurations are also hydrogen dependent, and wider than that of pristine 2D-GaAs with both PBE and HSE functionals. Even though DFT-vdW interactions increase the adsorption energies and reduce the equilibrium distances of H-GaAs systems, it presents, qualitatively, the same physical results on the stability and electronic properties of our studied systems with PBE functional. According to our results, 2D buckled gallium arsenide is a good candidate to be synthesized by hydrogen surface passivation as its group III-V partners 2D buckled gallium nitride and boron nitride. The hydrogenation of 2D-GaAs tunes the bandgap of pristine 2D-GaAs, which makes it a potential candidate for optoelectronic applications in the blue and violet ranges of the visible electromagnetic spectrum. |
| 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 |
000507894400001 |
Publication Date |
2019-12-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
2.7 |
Times cited |
2 |
Open Access |
|
| Notes |
; This work has been carried out by the financial support of Universidad del Norte and Colciencias (Administrative Department of Science, Technology and Research of Colombia) under Convocatoria 712-Convocatoria para proyectos de investigacion en Ciencias Basicas, ano 2015, Cod: 121571250192, Contrato 110-216. The authors gratefully acknowledge the support from the High Performance Computing core facility CalcUA and the TOPBOF project at the University of Antwerp, Belgium; and the computing time granted on the supercomputer Mogon at Johannes Gutenberg University Mainz (hpc.uni-mainz.de). ; |
Approved |
Most recent IF: 2.7; 2020 IF: 2.649 |
| Call Number |
UA @ admin @ c:irua:165644 |
Serial |
6330 |
| Permanent link to this record |
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| Author |
Vanrompay, H.; Buurlage, J.‐W.; Pelt, D.M.; Kumar, V.; Zhuo, X.; Liz‐Marzán, L.M.; Bals, S.; Batenburg, K.J. |
| Title |
Real‐Time Reconstruction of Arbitrary Slices for Quantitative and In Situ 3D Characterization of Nanoparticles |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Particle & Particle Systems Characterization |
Abbreviated Journal |
Part Part Syst Char |
| Volume |
37 |
Issue |
37 |
Pages |
2000073 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
A detailed 3D investigation of nanoparticles at a local scale is of great importance to connect their structure and composition to their properties. Electron tomography has therefore become an important tool for the 3D characterization of nanomaterials. 3D investigations typically comprise multiple steps, including acquisition, reconstruction, and analysis/quantification. Usually, the latter two steps are performed offline, at a dedicated workstation. This sequential workflow prevents on-the-fly control of experimental parameters to improve the quality of the 3D reconstruction, to select a relevant nanoparticle for further characterization or to steer an in-situ tomography experiment. Here, we present an efficient approach to overcome these limitations, based on the real-time reconstruction of arbitrary 2D reconstructed slices through a 3D object. Implementation of this method may lead to generalized implementation of electron tomography for routine nanoparticle characterization in 3D. |
| 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 |
000536357100001 |
Publication Date |
2020-05-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
10 |
Open Access |
OpenAccess |
| Notes |
Fonds Wetenschappelijk Onderzoek, 1S32617N ; Fonds Wetenschappelijk Onderzoek, G026718N ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 639.073.506 016.Veni.192.235 ; H.V. acknowledges financial support by the Research Foundation Flanders (FWO grant 1S32617N). S.B acknowledges financial support by the Research Foundation Flanders (FWO grant G026718N). Financial support was provided by The Netherlands Organization for Scientific Research (NWO), project numbers 639.073.506 and 016.Veni.192.235. This project received funding as well from the European Union’s Horizon 2020 research and innovation program under grant agreement No 731019 (EUSMI) and No 815128 (REALNANO). H.V. and J.-W.B contributed equally to this work.; sygma |
Approved |
Most recent IF: 2.7; 2020 IF: 4.474 |
| Call Number |
EMAT @ emat @c:irua:169704 |
Serial |
6371 |
| Permanent link to this record |
| |
|
| |
| Author |
Kahraman, Z.; Yagmurcukardes, M.; Sahin, H. |
| Title |
Functionalization of single-layer TaS₂ and formation of ultrathin Janus structures |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Materials Research |
Abbreviated Journal |
J Mater Res |
| Volume |
35 |
Issue |
11 |
Pages |
1397-1406 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Ab initio calculations are performed to investigate the structural, vibrational, electronic, and piezoelectric properties of functionalized single layers of TaS2. We find that single-layer TaS2 is a suitable host material for functionalization via fluorination and hydrogenation. The one-side fluorinated (FTaS2) and hydrogenated (HTaS2) single layers display indirect gap semiconducting behavior in contrast to bare metallic TaS2. On the other hand, it is shown that as both surfaces of TaS2 are saturated anti-symmetrically, the formed Janus structure is a dynamically stable metallic single layer. In addition, it is revealed that out-of-plane piezoelectricity is created in all anti-symmetric structures. Furthermore, the Janus-type single-layer has the highest specific heat capacity to which longitudinal and transverse acoustical phonon modes have contribution at low temperatures. Our findings indicate that single-layer TaS2 is suitable for functionalization via H and F atoms that the formed, anti-symmetric structures display distinctive electronic, vibrational, and piezoelectric properties. |
| 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 |
000540764300005 |
Publication Date |
2020-04-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0884-2914 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
1 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. Acknowledges financial support from the TUBITAK under the project number 117F095. H.S. acknowledges support from Turkish Academy of Sciences under the GEBIP program. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (M.Y.). ; |
Approved |
Most recent IF: 2.7; 2020 IF: 1.673 |
| Call Number |
UA @ admin @ c:irua:170185 |
Serial |
6525 |
| Permanent link to this record |
| |
|
| |
| Author |
Shi, P.; Ratkowsky, D.A.; Gielis, J. |
| Title |
The generalized Gielis geometric equation and its application |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
| Volume |
12 |
Issue |
4 |
Pages |
645-10 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Many natural shapes exhibit surprising symmetry and can be described by the Gielis equation, which has several classical geometric equations (for example, the circle, ellipse and superellipse) as special cases. However, the original Gielis equation cannot reflect some diverse shapes due to limitations of its power-law hypothesis. In the present study, we propose a generalized version by introducing a link function. Thus, the original Gielis equation can be deemed to be a special case of the generalized Gielis equation (GGE) with a power-law link function. The link function can be based on the morphological features of different objects so that the GGE is more flexible in fitting the data of the shape than its original version. The GGE is shown to be valid in depicting the shapes of some starfish and plant leaves. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000540222200156 |
Publication Date |
2020-04-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2073-8994 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
4 |
Open Access |
|
| Notes |
; This research was funded by the Jiangsu Government Scholarship for Overseas Studies (grant number: JS-2018-038). ; |
Approved |
Most recent IF: 2.7; 2020 IF: 1.457 |
| Call Number |
UA @ admin @ c:irua:168141 |
Serial |
6526 |
| Permanent link to this record |
| |
|
| |
| Author |
Lebedev, N.; Stehno, M.; Rana, A.; Gauquelin, N.; Verbeeck, J.; Brinkman, A.; Aarts, J. |
| Title |
Inhomogeneous superconductivity and quasilinear magnetoresistance at amorphous LaTiO₃/SrTiO₃ interfaces |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
33 |
Issue |
5 |
Pages |
055001 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We have studied the transport properties of LaTiO3/SrTiO3 (LTO/STO) heterostructures. In spite of 2D growth observed in reflection high energy electron diffraction, transmission electron microscopy images revealed that the samples tend to amorphize. Still, we observe that the structures are conducting, and some of them exhibit high conductance and/or superconductivity. We established that conductivity arises mainly on the STO side of the interface, and shows all the signs of the two-dimensional electron gas usually observed at interfaces between STO and LTO or LaAlO3, including the presence of two electron bands and tunability with a gate voltage. Analysis of magnetoresistance (MR) and superconductivity indicates the presence of spatial fluctuations of the electronic properties in our samples. That can explain the observed quasilinear out-of-plane MR, as well as various features of the in-plane MR and the observed superconductivity. |
| 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 |
|
Wos |
000588209300001 |
Publication Date |
2020-10-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
1 |
Open Access |
OpenAccess |
| Notes |
; NL and JA gratefully acknowledge the financial support of the research program DESCO, which is financed by the Netherlands Organisation for Scientific Research (NWO). The authors thank J Jobst, S Smink, K Lahabi and G Koster for useful discussion. ; |
Approved |
Most recent IF: 2.7; 2020 IF: 2.649 |
| Call Number |
UA @ admin @ c:irua:173679 |
Serial |
6545 |
| Permanent link to this record |
| |
|
| |
| Author |
Lavor, I.R.; da Costa, D.R.; Chaves, A.; Farias, G.A.; Macedo, R.; Peeters, F.M. |
| Title |
Magnetic field induced vortices in graphene quantum dots |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
32 |
Issue |
15 |
Pages |
155501 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The energy spectrum and local current patterns in graphene quantum dots (QD) are investigated for different geometries in the presence of an external perpendicular magnetic field. Our results demonstrate that, for specific geometries and edge configurations, the QD exhibits vortex and anti-vortex patterns in the local current density, in close analogy to the vortex patterns observed in the probability density current of semiconductor QD, as well as in the order parameter of mesoscopic superconductors. |
| 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 |
000520149200001 |
Publication Date |
2019-12-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
5 |
Open Access |
|
| Notes |
; This work was financially supported by the CAPES foundation and CNPq (Science Without Borders, PQ and FUNCAP/PRONEX programs). ; |
Approved |
Most recent IF: 2.7; 2020 IF: 2.649 |
| Call Number |
UA @ admin @ c:irua:167670 |
Serial |
6558 |
| Permanent link to this record |
| |
|
| |
| Author |
Bafekry, A.; Akgenc, B.; Ghergherehchi, M.; Peeters, F.M. |
| Title |
Strain and electric field tuning of semi-metallic character WCrCO₂ MXenes with dual narrow band gap |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
32 |
Issue |
35 |
Pages |
355504-355508 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Motivated by the recent successful synthesis of double-M carbides, we investigate structural and electronic properties of WCrC and WCrCO2 monolayers and the effects of biaxial and out-of-plane strain and electric field using density functional theory. WCrC and WCrCO2 monolayers are found to be dynamically stable. WCrC is metallic and WCrCO2 display semi-metallic character with narrow band gap, which can be controlled by strain engineering and electric field. WCrCO2 monolayer exhibits a dual band gap which is preserved in the presence of an electric field. The band gap of WCrCO2 monolayer increases under uniaxial strain while it becomes metallic under tensile strain, resulting in an exotic 2D double semi-metallic behavior. Our results demonstrate that WCrCO2 is a new platform for the study of novel physical properties in two-dimensional Dirac materials and which may provide new opportunities to realize high-speed low-dissipation devices. |
| 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 |
|
Wos |
000539375800001 |
Publication Date |
2020-04-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
45 |
Open Access |
|
| Notes |
; This work was supported by the National Research Foundation of Korea(NRF) Grant funded by the Korea government(MSIT)(NRF-2017R1A2B2011989). In addition, this work was supported by the Flemish Science Foundation (FW0-Vl). ; |
Approved |
Most recent IF: 2.7; 2020 IF: 2.649 |
| Call Number |
UA @ admin @ c:irua:169756 |
Serial |
6616 |
| Permanent link to this record |
| |
|
| |
| Author |
Hillen, M.; Legrand, S.; Dirkx, Y.; Janssens, K.; van der Snickt, G.; Caen, J.; Steenackers, G. |
| Title |
Cluster analysis of IR thermography data for differentiating glass types in historical leaded-glass windows |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Applied Sciences-Basel |
Abbreviated Journal |
Appl Sci-Basel |
| Volume |
10 |
Issue |
12 |
Pages |
4255-13 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Antwerp Cultural Heritage Sciences (ARCHES); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Infrared thermography is a fast, non-destructive and contactless testing technique which is increasingly used in heritage science. The aim of this study was to assess the ability of infrared thermography, in combination with a data clustering approach, to differentiate between the different types of historical glass that were included in a colorless leaded-glass windows during previous restoration interventions. Inspection of the thermograms and the application of two data mining techniques on the thermal data, i.e., k-means clustering and hierarchical clustering, allowed identifying different groups of window panes that show a different thermal behavior. Both clustering approaches arrive at similar groupings of the glass with a clear separation of three types. However, the lead cames that hold the glass panes appear to have a substantial impact on the thermal behavior of the surrounding glass, thus preventing classification of the smallest glass panes. For the larger panes, this was not a critical issue as the center of the glass remained unaffected. Subtle visual color differences between panes, implying a variation in coloring metal ions, was not always distinguished by IRT. Nevertheless, data clustering assisted infrared thermography shows potential as an efficient and swift method for documenting the material intervention history of leaded-glass windows during or in preparation of conservation treatments. |
| 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 |
000549351800001 |
Publication Date |
2020-06-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2076-3417 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.7; 2020 IF: 1.679 |
| Call Number |
UA @ admin @ c:irua:170012 |
Serial |
7674 |
| Permanent link to this record |
| |
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| |
| Author |
Silva, F.C.O.; Menezes, R.M.; Cabral, L.R.E.; de Souza Silva, C.C. |
| Title |
Formation and stability of conformal spirals in confined 2D crystals |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
32 |
Issue |
50 |
Pages |
505401 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the ground-state and dynamical properties of nonuniform two-dimensional (2D) clusters of long-range interacting particles. We demonstrate that, when the confining external potential is designed to produce an approximate 1/ r 2 density profile, the particles crystallize into highly ordered structures featuring spiral crystalline lines. Despite the strong inhomogeneity of the observed configurations, most of them are characterized by small density of topological defects, typical of conformal crystals, and the net topological charge induced by the simply-connected geometry of the system is concentrated near the cluster center. These crystals are shown to be robust with respect to thermal fluctuations up to a certain threshold temperature, above which the net charge is progressively redistributed from the center to the rest of the system and the topological order is lost. The crystals are also resilient to the shear stress produced by a small nonuniform azimuthal force field, rotating as a rigid body (RB). For larger forces, topological defects proliferate and the RB rotation gives place to plastic flow. |
| 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 |
|
Wos |
|
Publication Date |
2020-08-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
2.7 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.7; 2020 IF: 2.649 |
| Call Number |
UA @ admin @ c:irua:191093 |
Serial |
7978 |
| Permanent link to this record |
| |
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| |
| Author |
Huang, W.; Li, Y.; Niklas, K.J.; Gielis, J.; Ding, Y.; Cao, L.; Shi, P. |
| Title |
A superellipse with deformation and its application in describing the cross-sectional shapes of a square bamboo |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
| Volume |
12 |
Issue |
12 |
Pages |
2073 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Many cross-sectional shapes of plants have been found to approximate a superellipse rather than an ellipse. Square bamboos, belonging to the genus Chimonobambusa (Poaceae), are a group of plants with round-edged square-like culm cross sections. The initial application of superellipses to model these culm cross sections has focused on Chimonobambusa quadrangularis (Franceschi) Makino. However, there is a need for large scale empirical data to confirm this hypothesis. In this study, approximately 750 cross sections from 30 culms of C. utilis were scanned to obtain cross-sectional boundary coordinates. A superellipse exhibits a centrosymmetry, but in nature the cross sections of culms usually deviate from a standard circle, ellipse, or superellipse because of the influences of the environment and terrain, resulting in different bending and torsion forces during growth. Thus, more natural cross-sectional shapes appear to have the form of a deformed superellipse. The superellipse equation with a deformation parameter (SEDP) was used to fit boundary data. We find that the cross-sectional shapes (including outer and inner rings) of C. utilis can be well described by SEDP. The adjusted root-mean-square error of SEDP is smaller than that of the superellipse equation without a deformation parameter. A major finding is that the cross-sectional shapes can be divided into two types of superellipse curves: hyperellipses and hypoellipses, even for cross sections from the same culm. There are two proportional relationships between ring area and the product of ring length and width for both the outer and inner rings. The proportionality coefficients are significantly different, as a consequence of the two different superellipse types (i.e., hyperellipses and hypoellipses). The difference in the proportionality coefficients between hyperellipses and hypoellipses for outer rings is greater than that for inner rings. This work informs our understanding and quantifying of the longitudinal deformation of plant stems for future studies to assess the influences of the environment on stem development. This work is also informative for understanding the deviation of natural shapes from a strict rotational symmetry. |
| 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 |
000602546300001 |
Publication Date |
2020-12-15 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2073-8994 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.7; 2020 IF: 1.457 |
| Call Number |
UA @ admin @ c:irua:174472 |
Serial |
8622 |
| Permanent link to this record |
| |
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| |
| Author |
Kummamuru, N.B.; Eimer, D.A.; Idris, Z. |
| Title |
Viscosity measurement and correlation of unloaded and CO₂-loaded aqueous solutions of N-methyldiethanolamine + 2-amino-2-methyl-1-propanol |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Chemical And Engineering Data |
Abbreviated Journal |
J Chem Eng Data |
| Volume |
65 |
Issue |
6 |
Pages |
3072-3078 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
This work contributes to new and complementary experimental viscosity data for blended amine mixtures of aqueous N-methyldiethanolamine + 2-amino-2-methyl-1-propanol (MDEA + AMP) solutions with and without CO2 at different temperatures and mass fractions. For the unloaded MDEA + AMP solutions, measurements were conducted with total amine mass fractions ranging from 0.30 to 0.60. In the case of CO2-loaded aqueous MDEA + AMP solutions, experiments were performed at CO2 loadings ranging from 0.11 to 0.80. Proposed correlations were used to represent viscosity at the unloaded and CO2-loaded solutions within experimental uncertainty. |
| 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 |
000541740100016 |
Publication Date |
2020-05-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-9568; 1520-5134 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.6 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.6; 2020 IF: 2.323 |
| Call Number |
UA @ admin @ c:irua:180363 |
Serial |
8737 |
| Permanent link to this record |
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| |
| Author |
Al-Emam, E.; Soenen, H.; Caen, J.; Janssens, K. |
| Title |
Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Heritage science |
Abbreviated Journal |
|
| Volume |
8 |
Issue |
1 |
Pages |
106 |
| Keywords |
A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
| Abstract |
Since cleaning of artworks may cause undesirable physicochemical alterations and is a nonreversible procedure, it is mandatory to adopt the proper cleaning procedure. Such a procedure should remove undesired materials whilst preserving the original surface. In this regard, numerous gels have been developed and exploited for the cleaning of various artwork surfaces. Lately, agarose (AG) and polyvinyl alcohol-borax (PVA-B) hydrogels have been widely employed as cleaning tools by conservators. Both hydrogels show some limitations in specific cleaning practices. In this work, we investigated the influence of including increased levels of agarose into PVA-B systems. For this reason, we performed a detailed characterization on the double network (DN) hydrogel including the chemical structure, the liquid phase retention, the rheological behavior, and the self-healing behavior of various PVA-B/AG double network hydrogels. These new hydrogels revealed better properties than PVA-B hydrogels and obviated their limitations. The inclusion of AG into PVA-B systems enhanced the liquid retention capacity, shape-stability, and mechanical strength of the blend. Furthermore, AG minimized the expelling/syneresis issue that occurs when loading PVA-B systems with low polarity solvents or chelating agents. The resultant double network hydrogel exhibits relevant self-healing properties. The PVA-B/AG double network is a new and useful cleaning tool that can be added to the conservators' tool-kit. It is ideal for cleaning procedures dealing with porous and complex structured surfaces, vertical surfaces and for long time applications. |
| 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 |
000580572500001 |
Publication Date |
2020-10-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2050-7445 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.5 |
Times cited |
1 |
Open Access |
|
| Notes |
; Ehab Al-Emam thanks the Egyptian Ministry of Higher Education for funding his Ph.D. scholarship in addition to being grateful to University of Antwerp for additional funding. ; |
Approved |
Most recent IF: 2.5; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:173594 |
Serial |
6466 |
| Permanent link to this record |
| |
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| |
| Author |
Pourbabak, S.; Orekhov, A.; Schryvers, D. |
| Title |
Twin-jet electropolishing for damage-free transmission electron microscopy specimen preparation of metallic microwires |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Microscopy Research And Technique |
Abbreviated Journal |
Microsc Res Techniq |
| Volume |
|
Issue |
|
Pages |
1-7 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A method to prepare TEM specimens from metallic microwires and based on conventional twin-jet electropolishing is introduced. The wire is embedded in an opaque epoxy resin medium and the hardened resin is mechanically polished to reveal the wire on both sides. The resin containing wire is then cut into discs of the appropriate size. The obtained embedded wire is electropolished in a conventional twin-jet electropolishing machine until electron transparency in large areas without radiation damage is achieved. |
| Address |
|
| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000567944200001 |
Publication Date |
2020-09-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1059-910x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.5 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
; Fonds Wetenschappelijk Onderzoek, Grant/Award Number: G.0366.15N ; |
Approved |
Most recent IF: 2.5; 2020 IF: 1.147 |
| Call Number |
UA @ admin @ c:irua:171969 |
Serial |
6642 |
| Permanent link to this record |
| |
|
| |
| Author |
Eliaerts, J.; Meert, N.; Dardenne, P.; Baeten, V.; Pierna, J.-A.F.; Van Durme, F.; De Wael, K.; Samyn, N. |
| Title |
Comparison of spectroscopic techniques combined with chemometrics for cocaine powder analysis |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Analytical Toxicology |
Abbreviated Journal |
J Anal Toxicol |
| Volume |
44 |
Issue |
8 |
Pages |
851-860 |
| Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Spectroscopic techniques combined with chemometrics are a promising tool for analysis of seized drug powders. In this study, the performance of three spectroscopic techniques [Mid-InfraRed (MIR), Raman and Near-InfraRed (NIR)] was compared. In total, 364 seized powders were analyzed and consisted of 276 cocaine powders (with concentrations ranging from 4 to 99 w%) and 88 powders without cocaine. A classification model (using Support Vector Machines [SVM] discriminant analysis) and a quantification model (using SVM regression) were constructed with each spectral dataset in order to discriminate cocaine powders from other powders and quantify cocaine in powders classified as cocaine positive. The performances of the models were compared with gas chromatography coupled with mass spectrometry (GC-MS) and gas chromatography with flame-ionization detection (GC-FID). Different evaluation criteria were used: number of false negatives (FNs), number of false positives (FPs), accuracy, root mean square error of cross-validation (RMSECV) and determination coefficients (R-2). Ten colored powders were excluded from the classification data set due to fluorescence background observed in Raman spectra. For the classification, the best accuracy (99.7%) was obtained with MIR spectra. With Raman and NIR spectra, the accuracy was 99.5% and 98.9%, respectively. For the quantification, the best results were obtained with NIR spectra. The cocaine content was determined with a RMSECV of 3.79% and a R-2 of 0.97. The performance of MIR and Raman to predict cocaine concentrations was lower than NIR, with RMSECV of 6.76% and 6.79%, respectively and both with a R-2 of 0.90. The three spectroscopic techniques can be applied for both classification and quantification of cocaine, but some differences in performance were detected. The best classification was obtained with MIR spectra. For quantification, however, the RMSECV of MIR and Raman was twice as high in comparison with NIR. Spectroscopic techniques combined with chemometrics can reduce the workload for confirmation analysis (e.g., chromatography based) and therefore save time and resources. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000606735000011 |
Publication Date |
2020-08-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0146-4760; 1945-2403 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.5 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.5; 2020 IF: 2.409 |
| Call Number |
UA @ admin @ c:irua:175117 |
Serial |
7697 |
| Permanent link to this record |
| |
|
| |
| Author |
Simonsen, K.P.; Poulsen, J.N.; Vanmeert, F.; Ryhl-Svendsen, M.; Bendix, J.; Sanyova, J.; Janssens, K.; Mederos-Henry, F. |
| Title |
Formation of zinc oxalate from zinc white in various oil binding media: the influence of atmospheric carbon dioxide by reaction with 13CO2 |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Heritage science |
Abbreviated Journal |
|
| Volume |
8 |
Issue |
1 |
Pages |
126 |
| Keywords |
A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The formation of metal oxalates in paintings has recently gained a great deal of interest within the field of heritage science as several types of oxalate compounds have been identified in oil paintings. The present work investigates the formation of metal oxalates in linseed oil in the presence of the artists' pigments zinc white, calcite, lead white, zinc yellow, chrome yellow, cadmium yellow, cobalt violet, and verdigris. The oil paint films were artificially photo-aged by exposure to UVA light at low and high relative humidity, and afterwards analysed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The results showed that, compared to the other pigments investigated, zinc white is especially prone to metal oxalate formation and that high humidity is a crucial factor in this process. Consequently, the reactivity and photo-aging of ZnO in various oil binding media was investigated further under simulated solar radiation and at high relative humidity levels. ATR-FTIR showed that zinc oxalate is formed in all oil binding media while X-ray powder diffraction (PXRD) revealed it was mainly present in an amorphous state. To examine whether atmospheric CO2(g) has any influence on the formation of zinc oxalate, experiments with isotopically enriched (CO2(g))-C-13 were performed. Based on ATR-FTIR measurements, neither (ZnC2O4)-C-13 nor (ZnCO3)-C-13 were formed which suggests that the carbon source for the oxalate formation is most likely the paint itself (and its oil component) and not the surrounding atmosphere. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000596527000001 |
Publication Date |
2020-12-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2050-7445 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.5 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.5; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:174381 |
Serial |
7979 |
| Permanent link to this record |
| |
|
| |
| Author |
Alvarez-Martin, A.; George, J.; Kaplan, E.; Osmond, L.; Bright, L.; Newsome, G.A.; Kaczkowski, R.; Vanmeert, F.; Kavich, G.; Heald, S. |
| Title |
Identifying VOCs in exhibition cases and efflorescence on museum objects exhibited at Smithsonian’s National Museum of the American Indian-New York |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Heritage science |
Abbreviated Journal |
|
| Volume |
8 |
Issue |
1 |
Pages |
115 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Two mass spectrometry (MS) methods, solid-phase microextraction gas chromatography (SPME–GC–MS) and direct analysis in real time (DART-MS), have been explored to investigate widespread efflorescence observed on exhibited objects at the Smithsonian’s National Museum of the American Indian in New York (NMAI-NY). Both methods show great potential, in terms of speed of analysis and level of information, for identifying the organic component of the efflorescence as 2,2,6,6-tetramethyl-4-piperidinol (TMP-ol) emitted by the structural adhesive (Terostat MS 937) used for exhibit case construction. The utility of DART-MS was proven by detecting the presence of TMP-ol in construction materials in a fraction of the time and effort required for SPME–GC–MS analysis. In parallel, an unobtrusive SPME sampling strategy was used to detect volatile organic compounds (VOCs) accumulated in the exhibition cases. This sampling technique can be performed by collections and conservation staff at the museum and shipped to an off-site laboratory for analysis. This broadens the accessibility of MS techniques to museums without access to instrumentation or in-house analysis capabilities. |
| Address |
|
| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000589423700001 |
Publication Date |
2020-11-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2050-7445 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.5 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.5; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:181925 |
Serial |
8056 |
| Permanent link to this record |
| |
|
| |
| Author |
van Loon, A.; Noble, P.; de Man, D.; Alfeld, M.; Callewaert, T.; van der Snickt, G.; Janssens, K.; Dik, J. |
| Title |
The role of smalt in complex pigment mixtures in Rembrandt'sHomer1663: combining MA-XRF imaging, microanalysis, paint reconstructions and OCT |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Heritage science |
Abbreviated Journal |
|
| Volume |
8 |
Issue |
1 |
Pages |
90-19 |
| Keywords |
A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
| Abstract |
As part of the NWO Science4ArtsREVISRembrandtproject (2012-2018), novel chemical imaging techniques were developed and applied to the study of Rembrandt's late experimental painting technique (1651-1669). One of the unique features in his late paintings is his abundant use of smalt: a blue cobalt glass pigment that he often combined with organic lake pigments, earth pigments and blacks. Since most of these smalt-containing paints have discolored over time, we wanted to find out more about how these paintings may have originally looked, and what the role of smalt was in his paint. This paper reports on the use of smalt in complex pigment mixtures in Rembrandt'sHomer(1663), Mauritshuis, The Hague. Macroscopic X-ray fluorescence imaging (MA-XRF) assisted by computational analysis, in combination with SEM-EDX analysis of paint cross-sections, provides new information about the distribution and composition of the smalt paints in the painting. Paint reconstructions were carried out to investigate the effect of different percentages of smalt on the overall color, the drying properties, translucency and texture of the paint. Results show that the influence of (the originally blue) smalt on the intended color of the paint of theHomeris minimal. However, in mixtures with high percentages of smalt, or when combined with more transparent pigments, it was concluded that the smalt did produce a cooler and darker paint. It was also found that the admixture of opaque pigments reduced the translucent character of the smalt. The drying tests show that the paints with (cobalt-containing) smalt dried five times faster compared to those with glass (without cobalt). Most significantly, the texture of the paint was strongly influenced by adding smalt, creating a more irregular surface topography with clearly pronounced brushstrokes. Optical coherence tomography (OCT) was used as an additional tool to reveal differences in translucency and texture between the different paint reconstructions. In conclusion, this study confirmed earlier assumptions that Rembrandt used substantial amounts of smalt in his late paintings, not for its blue color, but to give volume and texture to his paints, to deepen their colors and to make them dry faster. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000565893700001 |
Publication Date |
2020-09-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2050-7445 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.5 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.5; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:171995 |
Serial |
8659 |
| Permanent link to this record |
| |
|
| |
| Author |
McNaughton, B.; Milošević, M.V.; Perali, A.; Pilati, S. |
| Title |
Boosting Monte Carlo simulations of spin glasses using autoregressive neural networks |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review E |
Abbreviated Journal |
Phys Rev E |
| Volume |
101 |
Issue |
5 |
Pages |
053312 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The autoregressive neural networks are emerging as a powerful computational tool to solve relevant problems in classical and quantum mechanics. One of their appealing functionalities is that, after they have learned a probability distribution from a dataset, they allow exact and efficient sampling of typical system configurations. Here we employ a neural autoregressive distribution estimator (NADE) to boost Markov chain Monte Carlo (MCMC) simulations of a paradigmatic classical model of spin-glass theory, namely, the two-dimensional Edwards-Anderson Hamiltonian. We show that a NADE can be trained to accurately mimic the Boltzmann distribution using unsupervised learning from system configurations generated using standard MCMC algorithms. The trained NADE is then employed as smart proposal distribution for the Metropolis-Hastings algorithm. This allows us to perform efficient MCMC simulations, which provide unbiased results even if the expectation value corresponding to the probability distribution learned by the NADE is not exact. Notably, we implement a sequential tempering procedure, whereby a NADE trained at a higher temperature is iteratively employed as proposal distribution in a MCMC simulation run at a slightly lower temperature. This allows one to efficiently simulate the spin-glass model even in the low-temperature regime, avoiding the divergent correlation times that plague MCMC simulations driven by local-update algorithms. Furthermore, we show that the NADE-driven simulations quickly sample ground-state configurations, paving the way to their future utilization to tackle binary optimization problems. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000535862000014 |
Publication Date |
2020-05-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1539-3755; 1550-2376 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.366 |
Times cited |
15 |
Open Access |
|
| Notes |
; The authors thank I. Murray, G. Carleo, and F. RicciTersenghi for useful discussions. Financial support from the FAR2018 project titled “Supervised machine learning for quantum matter and computational docking” of the University of Camerino and from the Italian MIUR under Project No. PRIN2017 CEnTraL 20172H2SC4 is gratefully acknowledged. S.P. also acknowledges the CINECA award under the ISCRA initiative, for the availability of high performance computing resources and support. M.V.M. gratefully acknowledges the Visiting Professorship program at the University of Camerino that facilitated the collaboration in this work. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:170244 |
Serial |
6463 |
| Permanent link to this record |
| |
|
| |
| Author |
Jalali, H.; Ghorbanfekr, H.; Hamid, I.; Neek-Amal, M.; Rashidi, R.; Peeters, F.M. |
| Title |
Out-of-plane permittivity of confined water |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review E |
Abbreviated Journal |
Phys Rev E |
| Volume |
102 |
Issue |
2 |
Pages |
022803 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
The dielectric properties of confined water is of fundamental interest and is still controversial. For water confined in channels with height smaller than h = 8 angstrom, we found a commensurability effect and an extraordinary decrease in the out-of-plane dielectric constant down to the limit of the dielectric constant of optical water. Spatial resolved polarization density data obtained from molecular dynamics simulations are found to be antisymmetric across the channel and are used as input in a mean-field model for the dielectric constant as a function of the height of the channel for h > 15 angstrom. Our results are in excellent agreement with a recent experiment [L. Fumagalli et al., Science 360, 1339 (2018)]. |
| Address |
|
| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000560660400004 |
Publication Date |
2020-08-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1539-3755; 1550-2376 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.366 |
Times cited |
38 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:171157 |
Serial |
6574 |
| Permanent link to this record |
| |
|
| |
| Author |
Cagno, S.; Lind, O.C.; Popic, J.M.; Skipperud, L.; De Nolf, W.; Nuyts, G.; Vanmeert, F.; Jaroszewicz, J.; Janssens, K.; Salbu, B. |
| Title |
Micro-analytical characterization of thorium-rich aggregates from Norwegian NORM sites (Fen Complex, Telemark) |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Environmental Radioactivity |
Abbreviated Journal |
J Environ Radioactiv |
| Volume |
219 |
Issue |
|
Pages |
106273 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
In this study we performed microscopic characterization of mineral particles that were collected in the thorium-rich Fen Complex in Norway and identified and isolated based on autoradiography in function of their radioactivity. For this we combined information obtained with X-ray absorption mu-CT, mu-XRF and mu-XRD, both in bi- and in three-dimensional (tomographic) mode. We demonstrate that radionuclides and metals are heterogeneously distributed both within soil samples and within individual Th-enriched aggregates, which are characterised as low-density mineral bulk particles with high density material inclusions, where Th as well as several metals are highly concentrated. For these sites, it is important to take into account how these inhomogeneous distributions could affect the overall environmental behaviour of Th and progeny upon weathering due to human or environmental factors. Moreover, the estimated size of the Th-containing inclusions as determined in this work represents information of importance for the characterization of radionuclides and toxic metals exposure, as well as for assessing the viability of mining for Th and rare-earth metals in the Fen Complex and the associated environmental impact. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000535130500005 |
Publication Date |
2020-04-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0265-931x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.3 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.3; 2020 IF: 2.31 |
| Call Number |
UA @ admin @ c:irua:181195 |
Serial |
8229 |
| Permanent link to this record |
| |
|
| |
| Author |
Velazco, A.; Nord, M.; Béché, A.; Verbeeck, J. |
| Title |
Evaluation of different rectangular scan strategies for STEM imaging |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
|
Issue |
|
Pages |
113021 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
STEM imaging is typically performed by raster scanning a focused electron probe over a sample. Here we investigate and compare three different scan patterns, making use of a programmable scan engine that allows to arbitrarily set the sequence of probe positions that are consecutively visited on the sample. We compare the typical raster scan with a so-called ‘snake’ pattern where the scan direction is reversed after each row and a novel Hilbert scan pattern that changes scan direction rapidly and provides an homogeneous treatment of both scan directions. We experimentally evaluate the imaging performance on a single crystal test sample by varying dwell time and evaluating behaviour with respect to sample drift. We demonstrate the ability of the Hilbert scan pattern to more faithfully represent the high frequency content of the image in the presence of sample drift. It is also shown that Hilbert scanning provides reduced bias when measuring lattice parameters from the obtained scanned images while maintaining similar precision in both scan directions which is especially important when e.g. performing strain analysis. Compared to raster scanning with flyback correction, both snake and Hilbert scanning benefit from dose reduction as only small probe movement steps occur. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000544042800007 |
Publication Date |
2020-05-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.2 |
Times cited |
13 |
Open Access |
OpenAccess |
| Notes |
A.V., A.B. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. M.N. received support for this work from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 838001. J.V acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. |
Approved |
Most recent IF: 2.2; 2020 IF: 2.843 |
| Call Number |
EMAT @ emat @c:irua:169225 |
Serial |
6369 |
| Permanent link to this record |
| |
|
| |
| Author |
Fatermans, J.; den Dekker, Aj.; Müller-Caspary, K.; Gauquelin, N.; Verbeeck, J.; Van Aert, S. |
| Title |
Atom column detection from simultaneously acquired ABF and ADF STEM images |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
219 |
Issue |
|
Pages |
113046 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
In electron microscopy, the maximum a posteriori (MAP) probability rule has been introduced as a tool to determine the most probable atomic structure from high-resolution annular dark-field (ADF) scanning transmission electron microscopy (STEM) images exhibiting low contrast-to-noise ratio (CNR). Besides ADF imaging, STEM can also be applied in the annular bright-field (ABF) regime. The ABF STEM mode allows to directly visualize light-element atomic columns in the presence of heavy columns. Typically, light-element nanomaterials are sensitive to the electron beam, limiting the incoming electron dose in order to avoid beam damage and leading to images exhibiting low CNR. Therefore, it is of interest to apply the MAP probability rule not only to ADF STEM images, but to ABF STEM images as well. In this work, the methodology of the MAP rule, which combines statistical parameter estimation theory and model-order selection, is extended to be applied to simultaneously acquired ABF and ADF STEM images. For this, an extension of the commonly used parametric models in STEM is proposed. Hereby, the effect of specimen tilt has been taken into account, since small tilts from the crystal zone axis affect, especially, ABF STEM intensities. Using simulations as well as experimental data, it is shown that the proposed methodology can be successfully used to detect light elements in the presence of heavy elements. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000594768500005 |
Publication Date |
2020-06-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.2 |
Times cited |
9 |
Open Access |
OpenAccess |
| 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, EOS 30489208). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 770887). The authors acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 823717 – ESTEEM3. The direct electron detector (Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. K. M. C. acknowledges funding from the Initiative and Network Fund of the Helmholtz Association (Germany) under contract VH-NG-1317. The authors thank Mark Huijben from the University of Twente (Enschede, The Netherlands) for providing the LiMn2O4 sample used in section 4.2 of this study. N. G., J. V., and S. V. A. acknowledge funding from the University of Antwerp through the Concerted Research Actions (GOA) project Solarpaint and the TOP project. |
Approved |
Most recent IF: 2.2; 2020 IF: 2.843 |
| Call Number |
EMAT @ emat @c:irua:169706 |
Serial |
6373 |
| Permanent link to this record |
