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Author |
Volodin, A.; Van Haesendonck, C.; Leenaerts, O.; Partoens, B.; Peeters, F.M. |
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Title |
Stress dependence of the suspended graphene work function : vacuum Kelvin probe force microscopy and density functional theory |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
110 |
Issue |
19 |
Pages |
193101 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We report on work function measurements on graphene, which is exfoliated over a predefined array of wells in silicon oxide, by Kelvin probe force microscopy operating in a vacuum. The obtained graphene sealed microchambers can support large pressure differences, providing controllable stretching of the nearly impermeable graphene membranes. These measurements allow detecting variations of the work function induced by the mechanical stresses in the suspended graphene where the work function varies linearly with the strain and changes by 62 +/- 2 meV for 1 percent of strain. Our related ab initio calculations result in a work function variation that is a factor of 1.4 larger than the experimental value. The limited discrepancy between the theory and the experiment can be accounted for by a charge transfer from the unstrained to the strained graphene regions. Published by AIP Publishing. |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
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Language |
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Wos |
000402319200036 |
Publication Date  |
2017-05-08 |
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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 |
0003-6951; 1077-3118 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
8 |
Open Access |
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Notes |
; The authors wish to thank A. Klekachev (IMEC Leuven, Belgium) for the fabrication of the samples. This work was supported by the Science Foundation-Flanders (FWO, Belgium). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government-Department EWI. The Hercules Foundation also funded the scanning probe microscopy equipment. ; |
Approved |
Most recent IF: 3.411 |
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Call Number |
UA @ lucian @ c:irua:144279 |
Serial |
4690 |
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Author |
Ozden, A.; Ay, F.; Sevik, C.; Perkgoz, N.K. |
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Title |
CVD growth of monolayer MoS2: Role of growth zone configuration and precursors ratio |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Japanese journal of applied physics |
Abbreviated Journal |
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Volume |
56 |
Issue |
6s:[1] |
Pages |
06gg05 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Single-layer, large-scale two-dimensional material growth is still a challenge for their wide-range usage. Therefore, we carried out a comprehensive study of monolayer MoS2 growth by CVD investigating the influence of growth zone configuration and precursors ratio. We first compared the two commonly used approaches regarding the relative substrate and precursor positions, namely, horizontal and face-down configurations where facedown approach is found to be more favorable to obtain larger flakes under identical growth conditions. Secondly, we used different types of substrate holders to investigate the influence of the Mo and S vapor confinement on the resulting diffusion environment. We suggest that local changes of the S to Mo vapor ratio in the growth zone is a key factor for the change of shape, size and uniformity of the resulting MoS2 formations, which is also confirmed by performing depositions under different precursor ratios. Therefore, to obtain continuous monolayer films, the S to Mo vapor ratio is needed to be kept within a certain range throughout the substrate. As a conclusion, we obtained monolayer triangles with a side length of 90 mu m and circles with a diameter of 500 mu m and continuous films with an area of 85 0 mu m x 1 cm when the S-to-Mo vapor ratio is optimized. (C) 2017 The Japan Society of Applied Physics |
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Wos |
000401059800003 |
Publication Date |
2017-05-08 |
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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 |
0021-4922; 1347-4065 |
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:193783 |
Serial |
7747 |
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Author |
Kleibert, A.; Balan, A.; Yanes, R.; Derlet, P.M.; Vaz, C.A.F.; Timm, M.; Fraile Rodríguez, A.; Béché, A.; Verbeeck, J.; Dhaka, R.S.; Radovic, M.; Nowak, U.; Nolting, F. |
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Title |
Direct observation of enhanced magnetism in individual size- and shape-selected 3d transition metal nanoparticles |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
95 |
Issue |
95 |
Pages |
195404 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Magnetic nanoparticles are critical building blocks for future technologies ranging from nanomedicine to spintronics. Many related applications require nanoparticles with tailored magnetic properties. However, despite significant efforts undertaken towards this goal, a broad and poorly understood dispersion of magnetic properties is reported, even within monodisperse samples of the canonical ferromagnetic 3d transition metals. We address this issue by investigating the magnetism of a large number of size- and shape-selected, individual nanoparticles of Fe, Co, and Ni using a unique set of complementary characterization techniques. At room temperature, only superparamagnetic behavior is observed in our experiments for all Ni nanoparticles within the investigated sizes, which range from 8 to 20 nm. However, Fe and Co nanoparticles can exist in two distinct magnetic states at any size in this range: (i) a superparamagnetic state, as expected from the bulk and surface anisotropies known for the respective materials and as observed for Ni, and (ii) a state with unexpected stable magnetization at room temperature. This striking state is assigned to significant modifications of the magnetic properties arising from metastable lattice defects in the core of the nanoparticles, as concluded by calculations and atomic structural characterization. Also related with the structural defects, we find that the magnetic state of Fe and Co nanoparticles can be tuned by thermal treatment enabling one to tailor their magnetic properties for applications. This paper demonstrates the importance of complementary single particle investigations for a better understanding of nanoparticle magnetism and for full exploration of their potential for applications. |
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Wos |
000400665300002 |
Publication Date |
2017-05-05 |
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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 |
2469-9950 |
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 |
21 |
Open Access |
OpenAccess |
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Notes |
We thank A. Weber, R. Schelldorfer, and J. Krbanjevic (Paul Scherrer Institut) for technical assistance. This paper was supported by the Swiss Nanoscience Institute, University of Basel. A.F.R. acknowledges support from the MICIIN “Ramón y Cajal” Programme. A.B. and J.V. acknowledge funding from the European Union under the European Research Council (ERC) Starting Grant No. 278510 VORTEX and under a contract for Integrated Infrastructure Initiative ESTEEM2 No. 312483. R.Y. and U.N. thank the Deutsche Forschungsgemeinschaft for financial support via Sonderforschungsbereich 1214. Part of this work was performed at the Surface/Interface: Microscopy (SIM) beamline of the Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland. |
Approved |
Most recent IF: 3.836 |
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Call Number |
EMAT @ emat @ c:irua:143634UA @ admin @ c:irua:143634 |
Serial |
4575 |
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Author |
Clauwaert, P.; Muys, M.; Alloul, A.; De Paepe, J.; Luther, A.; Sun, X.; Ilgrande, C.; Christiaens, M.E.R.; Hu, X.; Zhang, D.; Lindeboom, R.E.F.; Sas, B.; Rabaey, K.; Boon, N.; Ronsse, F.; Geelen, D.; Vlaeminck, S.E. |
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Title |
Nitrogen cycling in bioregenerative life support systems : challenges for waste refinery and food production processes |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Progress in aerospace sciences |
Abbreviated Journal |
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Volume |
91 |
Issue |
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Pages |
87-98 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
In order to sustain human life in an isolated environment, an efficient conversion of wasted nutrients to food might become mandatory. This is particularly the case for space missions where resupply from earth or in-situ resource utilization is not possible or desirable. A combination of different technologies is needed to allow full recycling of e.g. nitrogenous compounds in space. In this review, an overview is given of the different essential processes and technologies that enable closure of the nitrogen cycle in Bioregenerative Life Support Systems (BLSS). Firstly, a set of biological and physicochemical refinery stages ensures efficient conversion of waste products into the building blocks, followed by the production of food with a range of biological methods. For each technology, bottlenecks are identified. Furthermore, challenges and outlooks are presented at the integrated system level. Space adaptation and integration deserve key attention to enable the recovery of nitrogen for the production of nutritional food in space, but also in closed loop systems on earth. |
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Wos |
000404699800005 |
Publication Date |
2017-05-04 |
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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 |
0376-0421; 1873-1724 |
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:148996 |
Serial |
8310 |
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Author |
Grieb, T.; Krause, F.F.; Mahr, C.; Zillmann, D.; Müller-Caspary, K.; Schowalter, M.; Rosenauer, A. |
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Title |
Optimization of NBED simulations for disc-detection measurements |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
181 |
Issue |
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Pages |
50-60 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Nano-beam electron diffraction (NBED) is a method which can be applied to measure lattice strain and polarisation fields in strained layer heterostructures and transistors. To investigate precision, accuracy and spatial resolution of such measurements in dependence of properties of the specimen as well as electron optical parameters, simulations of NBED patterns are required which allow to predict the result of common disc-detection algorithms. In this paper we demonstrate by focusing on the detection of the central disc in crystalline silicon that such simulations require to take several experimental characteristics into account in order to obtain results which are comparable to those from experimental NBED patterns. These experimental characteristics are the background intensity, the presence of Poisson noise caused by electron statistics and blurring caused by inelastic scattering and by the transfer quality of the microscope camera. By means of these optimized simulations, different effects of specimen properties on disc detection – such as strain, surface morphology and compositional changes on the nanometer scale – are investigated and discussed in the context of misinterpretation in experimental NBED evaluations. It is shown that changes in surface morphology and chemical composition lead to measured shifts of the central disc in the NBED pattern of tens to hundreds of grad. These shifts are of the same order of magnitude or even larger than shifts that could be caused by an electric polarisation field in the range of MV/cm. (C) 2017 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000411170800006 |
Publication Date |
2017-05-03 |
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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 |
0304-3991 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
Not_Open_Access |
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Notes |
; This work was supported by the German Research Foundation (DFG) under Contract No. R02057/11-1, R02057/4-2 and MU3660/1-1. ; |
Approved |
Most recent IF: 2.843 |
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Call Number |
UA @ lucian @ c:irua:146725 |
Serial |
4792 |
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Author |
Lin, A.; Truong, B.; Patel, S.; Kaushik, N.; Choi, E.H.; Fridman, G.; Fridman, A.; Miller, V. |
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Title |
Nanosecond-pulsed DBD plasma-generated reactive oxygen species trigger immunogenic cell death in A549 lung carcinoma cells through intracellular oxidative stress |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
International journal of molecular sciences |
Abbreviated Journal |
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Volume |
18 |
Issue |
5 |
Pages |
966 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
A novel application for non-thermal plasma is the induction of immunogenic cancer cell death for cancer immunotherapy. Cells undergoing immunogenic death emit danger signals which facilitate anti-tumor immune responses. Although pathways leading to immunogenic cell death are not fully understood; oxidative stress is considered to be part of the underlying mechanism. Here; we studied the interaction between dielectric barrier discharge plasma and cancer cells for oxidative stress-mediated immunogenic cell death. We assessed changes to the intracellular oxidative environment after plasma treatment and correlated it to emission of two danger signals: surface-exposed calreticulin and secreted adenosine triphosphate. Plasma-generated reactive oxygen and charged species were recognized as the major effectors of immunogenic cell death. Chemical attenuators of intracellular reactive oxygen species successfully abrogated oxidative stress following plasma treatment and modulated the emission of surface-exposed calreticulin. Secreted danger signals from cells undergoing immunogenic death enhanced the anti-tumor activity of macrophages. This study demonstrated that plasma triggers immunogenic cell death through oxidative stress pathways and highlights its potential development for cancer immunotherapy. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000404113900073 |
Publication Date |
2017-05-03 |
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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 |
1422-0067; 1661-6596 |
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:155654 |
Serial |
8292 |
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Author |
Longo, R.; Ferrarotti, M.; Garcia Sánchez, C.; Derudi, M.; Parente, A. |
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Title |
Advanced turbulence models and boundary conditions for flows around different configurations of ground-mounted buildings |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of wind engineering and industrial aerodynamics |
Abbreviated Journal |
J Wind Eng Ind Aerod |
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Volume |
167 |
Issue |
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Pages |
160-182 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
When dealing with Atmospheric Boundary Layer (ABL) simulations, commercial computational fluid dynamics (CFD) acquires a strategic resonance. Thanks to its good compromise between accuracy of results and calculation time, RANS still represents a valid alternative to more resource-demanding methods. However, focusing on the models' performances in urban studies, LES generally outmatches RANS results, even if the former is at least one order of magnitude more expensive. Consequently, the present work aims to propose a variety of approaches meant to solve some of the major problems linked to RANS simulations and to further improve its accuracy in typical urban contexts. All of these models are capable of switching from an undisturbed flux formulation to a disturbed one through a local deviation or a marker function. For undisturbed flows, a comprehensive approach is adopted, solving the issue of the erroneous stream-wise gradients affecting the turbulent profiles. Around obstacles, Non-Linear Eddy-Viscosity closures are adopted, due to their prominent capability in capturing the anisotropy of turbulence. The purpose of this work is then to propose a new Building Influence Area concept and to offer more affordable alternatives to LES simulations without sacrificing a good grade of accuracy. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000405766600013 |
Publication Date |
2017-05-02 |
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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 |
0167-6105 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.049 |
Times cited |
9 |
Open Access |
Not_Open_Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.049 |
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Call Number |
UA @ lucian @ c:irua:145191 |
Serial |
4713 |
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Author |
Ata, I.; Ben Dkhil, S.; Pfannmoeller, M.; Bals, S.; Duche, D.; Simon, J.-J.; Koganezawa, T.; Yoshimoto, N.; Videlot-Ackermann, C.; Margeat, O.; Ackermann, J.; Baeuerle, P. |
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Title |
The influence of branched alkyl side chains in A-D-A oligothiophenes on the photovoltaic performance and morphology of solution-processed bulk-heterojunction solar cells |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Organic chemistry frontiers : an international journal of organic chemistry |
Abbreviated Journal |
Org Chem Front |
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Volume |
4 |
Issue |
4 |
Pages |
1561-1573 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Besides providing sufficient solubility, branched alkyl chains also affect the film-forming and packing properties of organic semiconductors. In order to avoid steric hindrance as it is present in wide-spread alkyl chains comprising a branching point position at the C2-position, i.e., 2-ethylhexyl, the branching point can be moved away from the pi-conjugated backbone. In this report, we study the influence of the modification of the branching point position from the C2-position in 2-hexyldecylamine (1) to the C4-position in 4-hexyldecylamine (2) connected to the central dithieno[3,2-b: 2', 3'-d] pyrrole (DTP) moiety in a well-studied A-D-A oligothiophene on the optoelectronic properties and photovoltaic performance in solution- processed bulk heterojunction solar cells (BHJSCs) with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor material. Post-treatment of the photoactive layers is performed via solvent vapor annealing (SVA) in order to improve the film microstructure of the bulk heterojunction. The time evolution of nanoscale morphological changes is followed by combining scanning transmission electron microscopy with low-energy-loss spectroscopic imaging (STEM-SI), solid-state absorption spectroscopy, and two-dimensional grazing incidence X-ray diffraction (2D-GIXRD). Our results show an improvement of the photovoltaic performance that is dependent on the branching point position in the donor oligomer. Optical spacers are utilized to increase light absorption inside the co-oligomer 2-based BHJSCs leading to increased power conversion efficiencies (PCEs) of 8.2% when compared to the corresponding co-oligomer 1-based devices. A STEM-SI analysis of the respective device cross-sections of active layers containing 1 and 2 as donor materials indeed reveals significant differences in their respective active layer morphologies. |
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Corporate Author |
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Thesis |
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Publisher |
RSC Publishing |
Place of Publication |
London |
Editor |
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Language |
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Wos |
000406374800013 |
Publication Date |
2017-05-02 |
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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 |
2052-4129 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.955 |
Times cited |
24 |
Open Access |
OpenAccess |
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Notes |
; We acknowledge financial support by the European Commission under the project “SUNFLOWER” (FP7-ICT-2011-7, grant number: 287594) and S.B. acknowledges the ERC Starting Grant Colouratoms (335078). ; |
Approved |
Most recent IF: 4.955 |
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Call Number |
UA @ lucian @ c:irua:145176UA @ admin @ c:irua:145176 |
Serial |
4727 |
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Author |
Leenaerts, O.; Vercauteren, S.; Partoens, B. |
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Title |
Band alignment of lateral two-dimensional heterostructures with a transverse dipole |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
110 |
Issue |
110 |
Pages |
181602 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
It was recently shown that the electronic band alignment in lateral two-dimensional heterostructures is strongly dependent on the system geometry, such as heterostructure width and layer thickness. This is so even in the absence of polar edge terminations because of the appearance of an interface dipole between the two different materials. In this study, this work is expanded to include two-dimensional materials that possess an electronic dipole over their surface, i.e., in the direction transverse to the crystal plane. To this end, a heterostucture consisting of polar hydrofluorinated graphene and non-polar graphane layers is studied with first-principles calculations. As for nonpolar heterostructures, a significant geometry dependence is observed with two different limits for the band offset. For infinitely wide heterostructures, the potential step in the vacuum is equally divided over the two sides of the heterostructure, resulting in a finite potential step in the heterostructure. For infinitely thick heterostructure slabs, on the other hand, the band offset is reduced, similar to the three-dimensional case. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000400931900014 |
Publication Date |
2017-05-01 |
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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 |
0003-6951; 1077-3118 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
4 |
Open Access |
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Notes |
; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-VI). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government-department EWI. ; |
Approved |
Most recent IF: 3.411 |
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Call Number |
UA @ lucian @ c:irua:143755 |
Serial |
4586 |
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Author |
Cuypers, B.; Vermeylen, S.; Hammerschmid, D.; Trashin, S.; Rahemi, V.; Konijnenberg, A.; De Schutter, A.; Cheng, C.-H.C.; Giordano, D.; Verde, C.; De Wael, K.; Sobott, F.; Dewilde, S.; Van Doorslaer, S. |
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Title |
Antarctic fish versus human cytoglobins : the same but yet so different |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of inorganic biochemistry |
Abbreviated Journal |
J Inorg Biochem |
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Volume |
173 |
Issue |
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Pages |
66-78 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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| |
Abstract |
The cytoglobins of the Antarctic fish Chaenocephalus aceratus and Dissostichus mawsoni have many features in common with human cytoglobin. These cytoglobins are heme proteins in which the ferric and ferrous forms have a characteristic hexacoordination of the heme iron, i.e. axial ligation of two endogenous histidine residues, as confirmed by electron paramagnetic resonance, resonance Raman and optical absorption spectroscopy. The combined spectroscopic analysis revealed only small variations in the heme-pocket structure, in line with the small variations observed for the redox potential. Nevertheless, some striking differences were also discovered. Resonance Raman spectroscopy showed that the stabilization of an exogenous heme ligand, such as CO, occurs differently in human cytoglobin in comparison with Antarctic fish cytoglobins. Furthermore, while it has been extensively reported that human cytoglobin is essentially monomeric and can form an intramolecular disulfide bridge that can influence the ligand binding kinetics, 3D modeling of the Antarctic fish cytoglobins indicates that the cysteine residues are too far apart to form such an intramolecular bridge. Moreover, gel filtration and mass spectrometry reveal the occurrence of non-covalent multimers (up to pentamers) in the Antarctic fish cytoglobins that are formed at low concentrations. Stabilization of these oligomers by disulfide-bridge formation is possible, but not essential. If intermolecular disulfide bridges are formed, they influence the heme-pocket structure, as is shown by EPR measurements. |
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Place of Publication |
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Editor |
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Language |
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Wos |
000405159600007 |
Publication Date |
2017-04-28 |
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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 |
0162-0134 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.348 |
Times cited |
7 |
Open Access |
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| |
Notes |
; The authors acknowledge the support of the University of Antwerp GOA-BOF funding (28312), FWO funding (G.0687.13) and the Hercules foundation for funding of the Synapt G2 instrument. This study was carried out in the framework of the SCAR program “Antarctic Thresholds – Ecosystem Resilience and Adaptation” (AnT-ERA). It was financially supported by the Italian National Program for Antarctic Research (PNRA). Research of A. De Schutter is funded by a PhD grant of the Agency for Innovation by Science and Technology (121339) (IWT, Belgium). C-H C. Cheng acknowledges funding support from US National Science Foundation Polar Programs (ANT-1142158). ; |
Approved |
Most recent IF: 3.348 |
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| |
Call Number |
UA @ admin @ c:irua:144826 |
Serial |
5474 |
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| Permanent link to this record |
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Author |
Loreto, S.; Cuypers, B.; Brokken, J.; Van Doorslaer, S.; De Wael, K.; Meynen, V. |
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| |
Title |
The effect of the buffer solution on the adsorption and stability of horse heart myoglobin on commercial mesoporous titanium dioxide : a matter of the right choice |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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| |
Volume |
19 |
Issue |
21 |
Pages |
13503-13514 |
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| |
Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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| |
Abstract |
Despite the numerous studies on the adsorption of different proteins onto mesoporous titanium dioxide and indications on the important role of buffer solutions in bioactivity, a systematic study on the impact of the buffer on the protein incorporation into porous substrates is still lacking. We here studied the interaction between a commercial mesoporous TiO2 and three of the most used buffers for protein incorporation, i.e. HEPES, Tris and phosphate buffer. In addition, this paper analyzes the adsorption of horse heart myoglobin (hhMb) onto commercial mesoporous TiO2 as a model system to test the influence of buffers on the protein incorporation behavior in mesoporous TiO2. N2 sorption analysis, FT-IR and TGA/DTG measurements were used to evaluate the interaction between the buffers and the TiO2 surface, and the effect of such an interaction on hhMb adsorption. Cyclic voltammetry (CV) and electron paramagnetic resonance (EPR) were used to detect changes in the microenvironment surrounding the heme. The three buffers show a completely different interaction with the TiO2 surface, which drastically affects the adsorption of myoglobin as well as its structure and electrochemical activity. Therefore, special attention is required while choosing the buffer medium to avoid misguided evaluation of protein adsorption on mesoporous TiO2. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000402488300013 |
Publication Date |
2017-04-27 |
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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 |
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 |
2 |
Open Access |
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| |
Notes |
; We are grateful to Gert Nuyts for performing the XRF measurements, and Dr Stanislav Trashin for his assistance during the electrochemical experiments. This work is supported by the Research Foundation – Flanders (FWO) (grant G.0687.13) and the University of Antwerp (BOF project). ; |
Approved |
Most recent IF: 4.123 |
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| |
Call Number |
UA @ admin @ c:irua:143514 |
Serial |
5582 |
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| Permanent link to this record |
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Author |
Smolin, S.Y.; Choquette, A.K.; Wilks, R.G.; Gauquelin, N.; Félix, R.; Gerlach, D.; Ueda, S.; Krick, A.L.; Verbeeck, J.; Bär, M.; Baxter, J.B.; May, S.J. |
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| |
Title |
Energy Level Alignment and Cation Charge States at the LaFeO3/LaMnO3(001) Heterointerface |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Advanced Materials Interfaces |
Abbreviated Journal |
Adv Mater Interfaces |
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| |
Volume |
4 |
Issue |
4 |
Pages |
1700183 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The electronic properties of LaFeO 3 /LaMnO 3 epitaxial heterojunctions are investigated to determine the valence and conduction band offsets and the nominal Mn and Fe valence states at the interface. Studying a systematic series of (LaFeO 3 ) n /(LaMnO 3 ) m bilayers (m ≈ 50) epitaxially grown in the (001) orientation using molecular beam epitaxy, layer-resolved electron energy loss spectroscopy reveals a lack of significant interfacial charge transfer, with a nominal 3+ valence state observed for both Mn and Fe across the interface. Through a combination of variable angle spectroscopic ellipsometry and hard X-ray photoelectron spectroscopy, type I energy level alignments are obtained at the LaFeO 3 /LaMnO 3 interface with positive valence and conduction band offsets of (1.20 ± 0.07) eV and (0.5–0.7 ± 0.3) eV, respectively, with minimal band bending. Variable temperature resistivity measurements reveal that the bilayers remain insulating and that the presence of the heterojunction does not result in a conducting interface. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000406068400011 |
Publication Date |
2017-04-26 |
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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 |
2196-7350 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.279 |
Times cited |
14 |
Open Access |
Not_Open_Access |
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Notes |
The authors thank Dmytro Nykypanchuk for assistance with the near- infrared ellipsometry measurement of the LaMnO 3 film. S.Y.S., A.K.C., J.B.B, and S.J.M. acknowledge funding from the National Science Foundation under grant number ECCS-1201957. S.Y.S. acknowledges additional funding from the German Academic Exchange Service (DAAD) through the Research Internships in Science and Engineering (RISE) professional program 2015 ID 5708457. A.L.K. was funded by the National Science Foundation under grant number DMR-1151649. J.V. and N.G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp and from the FWO project G.0044.13N (Charge ordering). The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. Ellipsometry measurements of the LaMnO 3 film were carried out at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-ACO2-98CH10886. S.U. would like to thank the staff of HiSOR, Hiroshima University, and JAEA/Spring-8 for the development of HAXPES at BL15XU of SPring-8. The HAXPES measurements were performed with approval of NIMS Synchrotron X-ray Station (Proposal No. 2015B4601), and were partly supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The authors also thank HZB for the allocation of synchrotron radiation beamtime for HAXPES/XANES measurements. R.G.W., R.F, and M.B. are grateful to the Impuls- und Vernetzungsfonds of the Helmholtz Association (VH-NG-423).; National Science Foundation, ECCS-1201957 DMR-1151649 ; Deutscher Akademischer Austauschdienst, 2015 ID 5708457 ; GOA project; Fonds Wetenschappelijk Onderzoek, G.0044.13N ; Flemish Government; U.S. Department of Energy, DE-ACO2-98CH10886 ; Vernetzungsfonds of the Helmholtz Association, VH-NG-423 ; |
Approved |
Most recent IF: 4.279 |
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Call Number |
EMAT @ emat @ c:irua:142346UA @ admin @ c:irua:142346 |
Serial |
4553 |
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| Permanent link to this record |
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Author |
Ranjbar, S.; Hadipour, A.; Vermang, B.; Batuk, M.; Hadermann, J.; Garud, S.; Sahayaraj, S.; Meuris, M.; Brammertz, G.; da Cunha, A.F.; Poortmans, J. |
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Title |
P-N Junction Passivation in Kesterite Solar Cells by Use of Solution-Processed TiO2 Layer |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
IEEE journal of photovoltaics |
Abbreviated Journal |
Ieee J Photovolt |
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| |
Volume |
7 |
Issue |
7 |
Pages |
1130-1135 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
In this work, we used a solution-processed TiO2 layer between Cu2ZnSnSe4 and CdS buffer layer to reduce the recombination at the p–n junction. Introducing the TiO2 layer showed a positive impact on VOC but fill factor and efficiency decreased. Using a KCN treatment, we could create openings in the TiO2 layer, as confirmed by transmission electron microscopy measurements. Formation of these openings in the TiO2 layer led to the improvement of the short-circuit current, fill factor, and the efficiency of the modified solar cells. |
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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 |
000404258900026 |
Publication Date |
2017-04-25 |
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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 |
2156-3381 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.712 |
Times cited |
2 |
Open Access |
OpenAccess |
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Notes |
This work was supported in part by the European Union’s Horizon 2020 research and innovation program under Grant 640868, in part by the Flemish government, Department Economy, Science and Innovation, in part by the FEDER funds through the COMPETE 2020 Programme, and in part by the National Funds through FCT – Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013. The work of S. Ranjbar was supported by the Portuguese Science and Technology Foundation through Ph.D. grant SFRH/BD/78409/2011. The work of B. Vermang was supported by the Flemish Research Foundation FWO (mandate 12O4215N). |
Approved |
Most recent IF: 3.712 |
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Call Number |
EMAT @ emat @ c:irua:143986 |
Serial |
4583 |
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Author |
da Costa, D.R.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
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Title |
Valley filtering in graphene due to substrate-induced mass potential |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
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| |
Volume |
29 |
Issue |
21 |
Pages |
215502 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The interaction of monolayer graphene with specific substrates may break its sublattice symmetry and results in unidirectional chiral states with opposite group velocities in the different Dirac cones (Zarenia et al 2012 Phys. Rev. B 86 085451). Taking advantage of this feature, we propose a valley filter based on a transversal mass kink for low energy electrons in graphene, which is obtained by assuming a defect region in the substrate that provides a change in the sign of the substrate-induced mass and thus creates a non-biased channel, perpendicular to the kink, for electron motion. By solving the time-dependent Schrodinger equation for the tight-binding Hamiltonian, we investigate the time evolution of a Gaussian wave packet propagating through such a system and obtain the transport properties of this graphene-based substrate-induced quantum point contact. Our results demonstrate that efficient valley filtering can be obtained, provided: (i) the electron energy is sufficiently low, i.e. with electrons belonging mostly to the lowest sub-band of the channel, and (ii) the channel length (width) is sufficiently long (narrow). Moreover, even though the transmission probabilities for each valley are significantly affected by impurities and defects in the channel region, the valley polarization in this system is shown to be robust against their presence. |
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Place of Publication |
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Wos |
000400092700002 |
Publication Date |
2017-04-24 |
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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 |
0953-8984 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
15 |
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:152636 |
Serial |
8730 |
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Author |
Chin, C.-M.; Sena, R.P.; Hunter, E.C.; Hadermann, J.; Battle, P.D. |
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Title |
Interplay of structural chemistry and magnetism in perovskites : a study of CaLn2Ni2WO9: Ln=La, Pr, Nd |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
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Volume |
251 |
Issue |
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Pages |
224-232 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Polycrystalline samples of CaLn(2)Ni(2)WO(9) (Ln=La, Pr, Nd) have been synthesized and characterised by a combination of X-ray and neutron diffraction, electron microscopy and magnetometry. Each composition adopts a perovskite-like structure with a similar to 5.50, b similar to 5.56, c similar to 7.78 angstrom beta similar to 90.1 degrees in space group P2(1)/n. Of the two crystallographically distinct six-coordinate sites, one is occupied entirely (Ln=Pr) or predominantly (Ln=La, Nd) by Ni2+ and the other by Ni2+ and W6+ in a ratio of approximately 1:2. None of the compounds shows long-range magnetic order at 5 K. The magnetometry data show that the magnetic moments of the Ni2+ cations form a spin glass below 30 K in each case. The Pr3+ moments in CaPr2Ni2WO9 also freeze but the Nd3+ moments in CaNd2Ni2WO9 do not. This behaviour is contrasted with that observed in other (A,A')B2B'O-9 perovskites. |
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Corporate Author |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000402581200030 |
Publication Date |
2017-04-22 |
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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 |
0022-4596 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
OpenAccess |
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Notes |
; We thank EPSRC for funding through grant EP/M0189541. CMC thanks the Croucher Foundation and Oxford University for a graduate scholarship. We are grateful to Ivan da Silva who provided experimental assistance at ISIS and to Maria Batuk for help with the STEM-EDX analysis. ; |
Approved |
Most recent IF: 2.299 |
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Call Number |
UA @ lucian @ c:irua:144179 |
Serial |
4664 |
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Author |
Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Peeters, F.M. |
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Title |
Electrostatically confined trilayer graphene quantum dots |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
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Volume |
95 |
Issue |
15 |
Pages |
155434 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Electrically gating of trilayer graphene (TLG) opens a band gap offering the possibility to electrically engineer TLG quantum dots. We study the energy levels of such quantum dots and investigate their dependence on a perpendicular magnetic field B and different types of stacking of the graphene layers. The dots are modeled as circular and confined by a truncated parabolic potential which can be realized by nanostructured gates or position-dependent doping. The energy spectra exhibit the intervalley symmetry E-K(e) (m) = -E (h)(K') (m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number and K and K' label the two valleys. The electron and hole spectra for B = 0 are twofold degenerate due to the intervalley symmetry E-K (m) = E-K' [-(m + 1)]. For both ABC [alpha = 1.5 (1.2) for large (small) R] and ABA (alpha = 1) stackings, the lowest-energy levels show approximately a R-alpha dependence on the dot radius R in contrast with the 1/R-3 one for ABC-stacked dots with infinite-mass boundary. As functions of the field B, the oscillator strengths for dipole-allowed transitions differ drastically for the two types of stackings. |
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Corporate Author |
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Place of Publication |
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Wos |
000399797200003 |
Publication Date |
2017-04-22 |
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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 |
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 |
6 |
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:152652 |
Serial |
7878 |
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Author |
Centeno, S.A.; Hale, C.; Caro, F.; Cesaratto, A.; Shibayama, N.; Delaney, J.; Dooley, K.; van der Snickt, G.; Janssens, K.; Stein, S.A. |
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Title |
Van Gogh's Irises and Roses : the contribution of chemical analyses and imaging to the assessment of color changes in the red lake pigments |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Heritage science |
Abbreviated Journal |
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Volume |
5 |
Issue |
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Pages |
18 |
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Keywords |
A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Vincent van Gogh's still lifes Irises and Roses were investigated to shed light onto the degree to which the paintings had changed, both individually and in relation to each other since they were painted, particularly in regard to the fading of the red lakes. Non-invasive techniques, including macroscopic X-ray fluorescence mapping, reflectance imaging spectroscopy, and X-radiography, were combined with microanalytical techniques in a select number of samples. The in-depth microchemical analysis was necessary to overcome the complications that arise when evaluating by non-invasive methods alone the compositions of passages with complex layering and mixing of paints. The results obtained by these two approaches were complemented by color measurements performed on paint cross-sections and on protected edges, and with historical information provided by the artist's own descriptions, early reviews and reproductions, and the data was used to carry out digital color simulations that provided, to a certain extent, a visualization of how the paintings may have originally appeared. |
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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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Language |
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Wos |
000401365400001 |
Publication Date |
2017-04-21 |
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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 |
2050-7445 |
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 |
21 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:143748 |
Serial |
5903 |
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Author |
Berthelot, A.; Bogaerts, A. |
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Title |
Modeling of CO2Splitting in a Microwave Plasma: How to Improve the Conversion and Energy Efficiency |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
121 |
Issue |
121 |
Pages |
8236-8251 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Microwave plasmas are one of the most promising techniques for CO2 conversion into value-added chemicals and fuels since they are very energy efficient. Nevertheless, experiments show that this high energy efficiency is only reached at low pressures and significantly drops toward atmospheric pressure, which is a clear limitation for industrial applications. In this paper, we use a zerodimensional reaction kinetics model to simulate a CO2 microwave plasma in a pressure range from 50 mbar to 1 bar, in order to evaluate the reasons for this decrease in energy efficiency at atmospheric pressure. The code includes a detailed description of the vibrational kinetics of CO2, CO, and O2 as well as the energy exchanges between them because the vibrational kinetics is known to be crucial for energy efficient CO2 splitting. First, we use a self-consistent gas temperature calculation in order to assess the key performance indicators for CO2 splitting, i.e., the CO2 conversion and corresponding energy efficiency. Our results indicate that lower pressures and higher power densities lead to more vibrational excitation, which is beneficial for the conversion. We also demonstrate the key role of the gas temperature. The model predicts the highest conversion and energy efficiencies at pressures around 300 mbar, which is in agreement with experiments from the literature. We also show the beneficial aspect of fast gas cooling in the afterglow at high pressure. In a second step, we study in more detail the effects of pressure, gas temperature, and power density on the vibrational distribution function and on the dissociation and recombination mechanisms of CO2, which define the CO2 splitting efficiency. This study allows us to identify the limiting factors of CO2 conversion and to propose potential solutions to improve the process. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000400039300002 |
Publication Date |
2017-04-20 |
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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 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.536 |
Times cited |
47 |
Open Access |
OpenAccess |
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Notes |
Federaal Wetenschapsbeleid; |
Approved |
Most recent IF: 4.536 |
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Call Number |
PLASMANT @ plasmant @ c:irua:142809 |
Serial |
4567 |
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Author |
Ben Hafsia, A.; Hendrickx, M.; Batuk, M.; Khitouni, M.; Hadermann, J.; Greneche, J.-M.; Rammeh, N. |
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| |
Title |
Crystal structure study of manganese and titanium substituted BaLaFe2O6-δ |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
|
| |
Volume |
251 |
Issue |
251 |
Pages |
186-193 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Barium lanthanum ferrite and four Mn/Ti substituted materials were synthesized by the sol-gel method. The crystal structure of the materials was studied by a combination of X-ray powder diffraction, electron diffraction, scanning transmission electron microscopy and 57Fe Mössbauer spectrometry. BaLaFe2O6-δ has a cubic perovskite structure and Ba0.7La1.3FeMnO6-δ is distorted perovskite with the R-3c symmetry, both from electron diffraction and X-ray powder diffraction. However, according to transmission electron microscopy, the crystals of BaLaFeTiO6-δ, BaLaFeTi0.5Mn0.5O6-δ, and BaLaFe0.5Ti0.5MnO6-δ consist of nanodomains with different symmetries (Pm3m next to R-3c due to octahedral tilts), whereas the bulk X-ray powder diffraction patterns for these compounds correspond to the simple cubic structure. 57Fe Mössbauer spectrometry confirms that all materials contain high spin state Fe3+ ions which are strongly influenced by the chemical disorder
resulting from various cationic environments. |
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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 |
000402581200024 |
Publication Date |
2017-04-20 |
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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 |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.299 |
Times cited |
|
Open Access |
Not_Open_Access |
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| |
Notes |
This study has been supported by the Tunisian Ministry of Higher Education and Scientific Research and by the University of Antwerp BOF Grant 33024 funding scheme. |
Approved |
Most recent IF: 2.299 |
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| |
Call Number |
EMAT @ emat @ c:irua:143988 |
Serial |
4582 |
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| Permanent link to this record |
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| |
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Author |
Magnus, W.; Lemmens, L.; Brosens, F. |
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| |
Title |
Quantum canonical ensemble : a projection operator approach |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physica: A : theoretical and statistical physics |
Abbreviated Journal |
Physica A |
|
| |
Volume |
482 |
Issue |
|
Pages |
1-13 |
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| |
Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
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| |
Abstract |
Knowing the exact number of particles N, and taking this knowledge into account, the quantum canonical ensemble imposes a constraint on the occupation number operators. The constraint particularly hampers the systematic calculation of the partition function and any relevant thermodynamic expectation value for arbitrary but fixed N. On the other hand, fixing only the average number of particles, one may remove the above constraint and simply factorize the traces in Fock space into traces over single-particle states. As is well known, that would be the strategy of the grand-canonical ensemble which, however, comes with an additional Lagrange multiplier to impose the average number of particles. The appearance of this multiplier can be avoided by invoking a projection operator that enables a constraint-free computation of the partition function and its derived quantities in the canonical ensemble, at the price of an angular or contour integration. Introduced in the recent past to handle various issues related to particle-number projected statistics, the projection operator approach proves beneficial to a wide variety of problems in condensed matter physics for which the canonical ensemble offers a natural and appropriate environment. In this light, we present a systematic treatment of the canonical ensemble that embeds the projection operator into the formalism of second quantization while explicitly fixing N, the very number of particles rather than the average. Being applicable to both bosonic and fermionic systems in arbitrary dimensions, transparent integral representations are provided for the partition function Z(N) and the Helmholtz free energy F-N as well as for two- and four-point correlation functions. The chemical potential is not a Lagrange multiplier regulating the average particle number but can be extracted from FN+1 – F-N, as illustrated for a two-dimensional fermion gas. (C) 2017 Elsevier B.V. All rights reserved. |
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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 |
Amsterdam |
Editor |
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| |
Language |
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Wos |
000405885500001 |
Publication Date |
2017-04-20 |
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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 |
0378-4371 |
ISBN |
|
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 @ lucian @ c:irua:145145 |
Serial |
4722 |
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| Permanent link to this record |
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| |
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Author |
Shayeganfar, F.; Vasu, K.S.; Nair, R.R.; Peeters, F.M.; Neek-Amal, M. |
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| |
Title |
Monolayer alkali and transition-metal monoxides : MgO, CaO, MnO, and NiO |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
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|
| |
Volume |
95 |
Issue |
14 |
Pages |
144109 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Two-dimensional crystals with strong interactions between layers has attracted increasing attention in recent years in a variety of fields. In particular, the growth of a single layer of oxide materials (e.g., MgO, CaO, NiO, and MnO) over metallic substrates were found to display different physical properties than their bulk. In this study, we report on the physical properties of a single layer of metallic oxide materials and compare their properties with their bulk and other two-dimensional (2D) crystals. We found that the planar structure of metallic monoxides are unstable whereas the buckled structures are thermodynamically stable. Also, the 2D-MnO and NiO exhibit different magnetic (ferromagnetic) and optical properties than their bulk, whereas band-gap energy and linear stiffness are found to be decreasing from NiO to MgO. Our findings provide insight into oxide thin-film technology applications. |
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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 |
000399792400001 |
Publication Date |
2017-04-20 |
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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 |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
21 |
Open Access |
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| |
Notes |
|
Approved |
no |
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| |
Call Number |
UA @ admin @ c:irua:152654 |
Serial |
8278 |
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| Permanent link to this record |
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Author |
Zebrowski, D.P.; Peeters, F.M.; Szafran, B. |
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Title |
Driven spin transitions in fluorinated single- and bilayer-graphene quantum dots |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
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| |
Volume |
32 |
Issue |
6 |
Pages |
065016 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene as well as electrostatic electron traps induced in bilayer graphene are considered. The stationary states obtained within the tight-binding approach are used as the basis for description of the system dynamics. The dilute fluorination of the top layer lifts the valley degeneracy of the confined states and attenuates the orbital magnetic dipole moments due to current circulation within the flake. The spin-orbit coupling introduced by the surface deformation of the top layer induced by the adatoms allows the spin flips to be driven by the AC electric field. For the bilayer quantum dots the spin flip times is substantially shorter than the spin relaxation. Dynamical effects including many-photon and multilevel transitions are also discussed. |
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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 |
London |
Editor |
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Language |
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Wos |
000402405800007 |
Publication Date |
2017-04-19 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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| |
ISSN |
0268-1242 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
2.305 |
Times cited |
|
Open Access |
|
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| |
Notes |
; This work was supported by the National Science Centre according to decision DEC-2013/11/B/ST3/03837 and by the Flemish Science Foundation (FWO-VL). ; |
Approved |
Most recent IF: 2.305 |
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| |
Call Number |
UA @ lucian @ c:irua:144238 |
Serial |
4646 |
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| Permanent link to this record |
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Author |
Gholampour, N.; Chaemchuen, S.; Hu, Z.-Y.; Mousavi, B.; Van Tendeloo, G.; Verpoort, F. |
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Title |
Simultaneous creation of metal nanoparticles in metal organic frameworks via spray drying technique |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
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Volume |
322 |
Issue |
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Pages |
702-709 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In-situ fabrication of palladium(0) nanoparticles inside zeolitic imidazolate frameworks (ZIF-8) has been established via one-step facile spray-dry technique. Crystal structures and morphologies of the Pd@ZIF-8 samples are investigated by powder XRD, TEM, SAED, STEM, and EDX techniques. High angle annular dark field scanning transmission electron microscopy (HAAD-STEM) and 3D tomographic analysis confirm the presence of palladium nanoparticles inside the ZIF-8 structure. The porosity, surface area and N-2 physisorption properties are evaluated for Pd@ZIF-8 with various palladium contents. Furthermore, Pd@ZIF-8 samples are effectively applied as heterogeneous catalysts in alkenes hydrogenation. This straightforward method is able to speed up the synthesis of encapsulation of metal nanoparticles in metal organic frameworks. (C) 2017 Elsevier B.V. All rights reserved. |
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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 |
Lausanne |
Editor |
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Language |
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Wos |
000401594200069 |
Publication Date |
2017-04-19 |
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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 |
1385-8947; 0300-9467 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.216 |
Times cited |
14 |
Open Access |
OpenAccess |
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Notes |
; The authors would like to express their deep accolade to “State Key Laboratory of Advanced Technology for Materials Synthesis and Processing” for financial support. S.C. appreciates of the National Natural Science Foundation of China (303-41150231), the Fundamental Research Funds for the Central Universities (WUT: 2016IVA092) and the Research Fund for the Doctoral Program of Higher Education of China (471-40120222). N.G. thanks the Chinese Scholarship Council (CSC) for her Ph.D. study grant 2013GXZ985. Z.-Y. H and G. V.T. acknowledge the support from the EC Framework 7 program ESTEEM2 (Reference 312483). ; |
Approved |
Most recent IF: 6.216 |
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| |
Call Number |
UA @ lucian @ c:irua:144152 |
Serial |
4686 |
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| Permanent link to this record |
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Author |
García Sánchez, C.; Van Tendeloo, G.; Gorle, C. |
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Title |
Quantifying inflow uncertainties in RANS simulations of urban pollutant dispersion |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Atmospheric environment : an international journal |
Abbreviated Journal |
Atmos Environ |
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Volume |
161 |
Issue |
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Pages |
263-273 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Numerical simulations of flow and pollutant dispersion in urban environments have the potential to support design and policy decisions that could reduce the population's exposure to air pollution. Reynolds-averaged Navier-Stokes simulations are a common modeling technique for urban flow and dispersion, but several sources of uncertainty in the simulations can affect the accuracy of the results. The present study proposes a method to quantify the uncertainty related to variability in the inflow boundary conditions. The method is applied to predict flow and pollutant dispersion in downtown Oklahoma City and the results are compared to field measurements available from the Joint Urban 2003 measurement campaign. Three uncertain parameters that define the inflow profiles for velocity, turbulence kinetic energy and turbulence dissipation are defined: the velocity magnitude and direction, and the terrain roughness length. The uncertain parameter space is defined based on the available measurement data, and a non-intrusive propagation approach that employs 729 simulations is used to quantify the uncertainty in the simulation output. A variance based sensitivity analysis is performed to identify the most influential uncertain parameters, and it is shown that the predicted tracer concentrations are influenced by all three uncertain variables. Subsequently, we specify different probability distributions for the uncertain inflow variables based on the available measurement data and calculate the corresponding means and 95% confidence intervals for comparison with the field measurements at 35 locations in downtown Oklahoma City. (C) 2017 Elsevier Ltd. All rights reserved. |
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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 |
Oxford |
Editor |
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Language |
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Wos |
000403515900025 |
Publication Date |
2017-04-19 |
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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 |
1352-2310 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.629 |
Times cited |
17 |
Open Access |
OpenAccess |
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Notes |
; The first author's contribution to this work was supported by the doctoral (PhD) grant number 131423 for strategic basic research from the Agency for Innovation by Science and Technology in Flanders (IWT). This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number CTS160009 (Towns et al., 2014). ; |
Approved |
Most recent IF: 3.629 |
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Call Number |
UA @ lucian @ c:irua:145761 |
Serial |
4749 |
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Author |
Wang, D.; Liu, Y.; Ngo, H.H.; Zhang, C.; Yang, Q.; Peng, L.; He, D.; Zeng, G.; Li, X.; Ni, B.-J. |
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Title |
Approach of describing dynamic production of volatile fatty acids from sludge alkaline fermentation |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Bioresource technology |
Abbreviated Journal |
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Volume |
238 |
Issue |
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Pages |
343-351 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
In this work, a mathematical model was developed to describe the dynamics of fermentation products in sludge alkaline fermentation systems for the first time. In this model, the impacts of alkaline fermentation on sludge disintegration, hydrolysis, acidogenesis, acetogenesis, and methanogenesis processes are specifically considered for describing the high-level formation of fermentation products. The model proposed successfully reproduced the experimental data obtained from five independent sludge alkaline fermentation studies. The modeling results showed that alkaline fermentation largely facilitated the disintegration, acidogenesis, and acetogenesis processes and severely inhibited methanogenesis process. With the pH increase from 7.0 to 10.0, the disintegration, acidogenesis, and acetogenesis processes respectively increased by 53%, 1030%, and 30% while methane production decreased by 3800%.However, no substantial effect on hydrolysis process was found. The model also indicated that the pathway of acetoclastic methanogenesis was more severely inhibited by alkaline condition than that of hydrogentrophic methanogenesis. (C) 2017 Elsevier Ltd. All rights reserved. |
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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 |
000402485500042 |
Publication Date |
2017-04-19 |
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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 |
0960-8524 |
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:144155 |
Serial |
7489 |
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| Permanent link to this record |
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Author |
Ustarroz, J.; Geboes, B.; Vanrompay, H.; Sentosun, K.; Bals, S.; Breugelmans, T.; Hubin, A. |
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Title |
Electrodeposition of Highly Porous Pt Nanoparticles Studied by Quantitative 3D Electron Tomography: Influence of Growth Mechanisms and Potential Cycling on the Active Surface Area |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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Volume |
9 |
Issue |
9 |
Pages |
16168-16177 |
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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 |
Nanoporous Pt nanoparticles (NPs) are promising fuel cell catalysts due to their large surface area and increased electrocatalytic activity towards the oxygen reduction reaction (ORR). Herein, we report on the infuence of the growth mechanisms on the surface properties of electrodeposited Pt dendritic NPs with large surface areas. The electrochemically active surface was studied by hydrogen underpotential deposition (HUPD) and compared for the rst time to high angle annular dark eld scanning transmission electron microscopy (HAADF-STEM) quantitative 3D electron tomography of individual nanoparticles. Large nucleation overpotential leads to a large surface coverage of Pt roughened spheroids, which provide large roughness factor (Rf ) but low mass-speci c electrochemically active surface area (EASA). Lowering the nucleation overpotential leads to highly porous Pt NPs with pores protruding to the center of the structure. At the expense of smaller Rf , the obtained EASA values of these structures are in the range of these of large surface area supported fuel cell catalysts. The active surface area of the Pt dendritic NPs was measured by electron tomography and it was found that the potential cycling in the H adsorption/desorption and Pt oxidation/reduction region, which is generally performed to determine the EASA, leads to a signi cant reduction of that surface area due to a partial collapse of their dendritic and porous morphology. Interestingly, the extrapolation of the microscopic tomography results to macroscopic electrochemical parameters indicated that the surface properties measured by H UPD are comparable to the values measured on individual NPs by electron tomography after the degradation caused by the H UPD measurement. These results highlight that the combination of electrochemical and quantitative 3D surface analysis techniques is essential to provide insights into the surface properties, the electrochemical stability and, hence, the applicability of these materials. Moreover, it indicates that care must be taken with widely used electrochemical methods of surface area determination, especially in the case of large surface area and possibly unstable nanostructures, since the measured surface can be strongly a ected by the measurement itself. |
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Corporate Author |
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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 |
000401782500028 |
Publication Date |
2017-04-18 |
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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 |
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Series Issue |
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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 |
24 |
Open Access |
OpenAccess |
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Notes |
Jon Ustarroz acknowledges funding from the Fonds Wetenschappelijk Onderzoek in Flanders (FWO, postdoctoral grant 12I7816N). S. Bals acknowledges funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). S.B. and T.B. acknowledge the University of Antwerp for nancial support in the frame of a GOA project. H.V. gratefully acknowledges nancial support by the Flemish Fund for Scienti c Research (FWO Vlaanderen). All the authors acknowledge Laurens Stevaert for his contribution to the work presented in this manuscript. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara |
Approved |
Most recent IF: 7.504 |
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Call Number |
EMAT @ emat @ c:irua:142345UA @ admin @ c:irua:142345 |
Serial |
4552 |
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| Permanent link to this record |
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Author |
Khalilov, U.; Bogaerts, A.; Neyts, E.C. |
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Title |
Toward the Understanding of Selective Si Nano-Oxidation by Atomic Scale Simulations |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Accounts of chemical research |
Abbreviated Journal |
Accounts Chem Res |
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Volume |
50 |
Issue |
50 |
Pages |
796-804 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
The continuous miniaturization of nanodevices, such as transistors, solar cells, and optical fibers, requires the controlled synthesis of (ultra)thin gate oxides (<10 nm), including Si gate-oxide (SiO2) with high quality at the atomic scale. Traditional thermal growth of SiO2 on planar Si surfaces, however, does not allow one to obtain such ultrathin oxide due to either the high oxygen diffusivity at high temperature or the very low sticking ability of incident oxygen at low temperature. Two recent techniques, both operative at low (room) temperature, have been put forward to overcome these obstacles: (i) hyperthermal oxidation of planar Si surfaces and (ii) thermal or plasma-assisted oxidation of nonplanar Si surfaces, including Si nanowires (SiNWs). These nanooxidation processes are, however, often difficult to study experimentally, due to the key intermediate processes taking place on the nanosecond time scale.
In this Account, these Si nano-oxidation techniques are discussed from a computational point of view and compared to both hyperthermal and thermal oxidation experiments, as well as to well-known models of thermal oxidation, including the Deal−Grove, Cabrera−Mott, and Kao models and several alternative mechanisms. In our studies, we use reactive molecular dynamics (MD) and hybrid MD/Monte Carlo simulation techniques, applying the Reax force field. The incident energy of oxygen species is chosen in the range of 1−5 eV in hyperthermal oxidation of planar Si surfaces in order to prevent energy-induced damage. It turns out that hyperthermal growth allows for two growth modes, where the ultrathin oxide thickness depends on either (1) only the kinetic energy of the incident oxygen species at a growth temperature below Ttrans = 600 K, or (2) both the incident energy and the growth temperature at a growth temperature above Ttrans. These modes are specific to such ultrathin oxides, and are not observed in traditional thermal oxidation, nor theoretically considered by already existing models. In the case of thermal or plasma-assisted oxidation of small Si nanowires, on the other hand, the thickness of the ultrathin oxide is a function of the growth temperature and the nanowire diameter. Below Ttrans, which varies with the nanowire diameter, partially oxidized SiNW are formed, whereas complete oxidation to a SiO2 nanowire occurs only above Ttrans. In both nano-oxidation processes at lower temperature (T < Ttrans), final sandwich c-Si|SiOx|a-SiO2 structures are obtained due to a competition between overcoming the energy barrier to penetrate into Si subsurface layers and the compressive stress (∼2−3 GPa) at the Si crystal/oxide interface. The overall atomic-simulation results strongly indicate that the thickness of the intermediate SiOx (x < 2) region is very limited (∼0.5 nm) and constant irrespective of oxidation parameters. Thus, control over the ultrathin SiO2 thickness with good quality is indeed possible by accurately tuning the oxidant energy, oxidation temperature and surface curvature.
In general, we discuss and put in perspective these two oxidation mechanisms for obtaining controllable ultrathin gate-oxide films, offering a new route toward the fabrication of nanodevices via selective nano-oxidation. |
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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 |
000399859800016 |
Publication Date |
2017-04-18 |
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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 |
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Series Issue |
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Edition |
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ISSN |
0001-4842 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
20.268 |
Times cited |
5 |
Open Access |
OpenAccess |
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Notes |
Fonds Wetenschappelijk Onderzoek, 12M1315N ; |
Approved |
Most recent IF: 20.268 |
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Call Number |
PLASMANT @ plasmant @ c:irua:142638 |
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4561 |
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Author |
Guzzinati, G.; Béché, A.; Lourenço-Martins, H.; Martin, J.; Kociak, M.; Verbeeck, J. |
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Title |
Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams |
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A1 Journal article |
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Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
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Volume |
8 |
Issue |
8 |
Pages |
14999 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although the field is progressing swiftly, thanks to the availability of nanoscale manufacturing and analysis methods, fundamental properties such as the plasmonic excitations’ symmetries cannot be accessed directly, leading to a partial, sometimes incorrect, understanding of their properties. Here we overcome this limitation by deliberately shaping the wave function of an electron beam to match a plasmonic excitations’ symmetry in a modified transmission electron microscope. We show experimentally and theoretically that this offers selective detection of specific plasmon modes within metallic nanoparticles, while excluding modes with other symmetries. This method resembles the widespread use of polarized light for the selective excitation of plasmon modes with the advantage of locally probing the response of individual plasmonic objects and a far wider range of symmetry selection criteria. |
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Wos |
000399084300001 |
Publication Date |
2017-04-12 |
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ISSN |
2041-1723 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
12.124 |
Times cited |
84 |
Open Access |
OpenAccess |
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Notes |
; We thank F.J. Garcia de Abajo and D.M. Ugarte for interesting and fruitful discussion. This work was supported by funding from the European Research Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX. Financial support from the European Union under the Framework 7 program under a contract for an Integrated Infrastructure Initiative (Reference number 312483 ESTEEM2) is also gratefully acknowledged. Aluminum nanostructures were fabricated using the Nanomat nanofabrication facility. ; |
Approved |
Most recent IF: 12.124 |
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Call Number |
EMAT @ emat @ c:irua:142205UA @ admin @ c:irua:142205 |
Serial |
4548 |
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Mernissi Cherigui, E.A.; Sentosun, K.; Bouckenooge, P.; Vanrompay, H.; Bals, S.; Terryn, H.; Ustarroz, J. |
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Title |
A Comprehensive Study of the Electrodeposition of Nickel Nanostructures from Deep Eutectic Solvents: Self-Limiting Growth by Electrolysis of Residual Water |
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A1 Journal article |
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Year |
2017 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
121 |
Issue |
121 |
Pages |
9337-9347 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The electrodeposition of nickel nanostructures on glassy carbon was investigated in 1:2 choline chloride – urea (1:2 ChCl-U) deep eutectic solvent (DES). By combining electrochemical techniques with ex-situ FE-SEM, XPS, HAADF-STEM and EDX, the electrochemical processes occurring during nickel deposition were better understood. Special attention was given to the interaction between the solvent and the growing nickel nanoparticles. The application of a suffciently negative potential results into the electrocatlytic hydrolisis of residual water in the DES, which leads to the formation of a mixed layer of Ni/Ni(OH)2(ads). In addition, hydrogen bonds between hydroxide species and the DES components could be formed, quenching the growth of the nickel clusters favouring their aggregation. Due to these processes, a highly dense distribution of nickel nanostructures can be obtained within a wide potential range. Understanding the role of residual water and the interactions at the interface during metal electrodeposition from DESs is essential to produce supported nanostructures in a controllable way for a broad range of applications and technologies. |
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Wos |
000400881100027 |
Publication Date |
2017-04-12 |
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ISSN |
1932-7447 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
66 |
Open Access |
OpenAccess |
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Notes |
E.A. Mernissi Cherigui acknowledges funding from the Fonds Wetenschappelijk Onderzoek in Flanders (FWO, research project G019014N). S. Bals acknowledges funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). H.V. gratefully acknowledges financial support by the Flemish Fund for Scientifi c Research (FWO Vlaanderen). Finally, J. Ustarroz acknowledges funding from the Fonds Wetenschappelijk Onderzoek in Flanders (FWO, postdoctoral grant 12I7816N). (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara |
Approved |
Most recent IF: 4.536 |
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EMAT @ emat @ c:irua:142208UA @ admin @ c:irua:142208 |
Serial |
4551 |
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Houben, K.; Couet, S.; Trekels, M.; Menendez, E.; Peissker, T.; Seo, J.W.; Hu, M.Y.; Zhao, J.Y.; Alp, E.E.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Bessas, D.; Brown, S.A.; Vantomme, A.; Temst, K.; Van Bael, M.J. |
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Title |
Lattice dynamics in Sn nanoislands and cluster-assembled films |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
95 |
Issue |
15 |
Pages |
155413 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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To unravel the effects of phonon confinement, the influence of size and morphology on the atomic vibrations is investigated in Sn nanoislands and cluster-assembled films. Nuclear resonant inelastic x-ray scattering is used to probe the phonon densities of states of the Sn nanostructures which show significant broadening of the features compared to bulk phonon behavior. Supported by ab initio calculations, the broadening is attributed to phonon scattering and can be described within the damped harmonic oscillator model. Contrary to the expectations based on previous research, the appearance of high-energy modes above the cutoff energy is not observed. From the thermodynamic properties extracted from the phonon densities of states, it was found that grain boundary Sn atoms are bound by weaker forces than bulk Sn atoms. |
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American Physical Society |
Place of Publication |
New York, N.Y |
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Wos |
000401762400008 |
Publication Date |
2017-04-11 |
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ISSN |
2469-9969; 2469-9950 |
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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 |
5 |
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Notes |
; This work was supported by the Research Foundation-Flanders (FWO) and the Concerted Research Action (GOA/14/007). The authors acknowledge Hercules stichting (Projects No. AKUL/13/19 and No. AKUL/13/25). K.H. and S.C. thank the FWO for financial support. T.P. acknowledges the IWT for financial support. S.R., M.V.M., and B.P. acknowledge TOPBOF funding of the University of Antwerp Research Fund. J.W.S. acknowledges Hercules Stichting (Project No. AKUL/13/19). The authors want to thank R. Lieten for help with the XRD measurements and T. Picot for fruitful discussions. The authors gratefully acknowledge R. Ruffer and A. I. Chumakov for fruitful discussions and the European Synchrotron Radiation Facility for the measurement of the SnO<INF>2</INF> powder at the Nuclear Resonance beamline (ID-18). 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 @ lucian @ c:irua:144305 |
Serial |
4667 |
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