| Records |
| Author |
Fenu, A.; De Wilde, W.; Gaertner, M.; Weemaes, M.; de Gueldre, G.; van de Steene, B. |
| Title |
Elaborating the membrane life concept in a full scale hollow-fibers MBR |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Journal of membrane science |
Abbreviated Journal |
|
| Volume |
421 |
Issue |
|
Pages |
349-354 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
The membrane life-time has a strong impact on competitivity and viability of MBRs. This study critically analyzes the membrane life-time concept, approaching it through different assessment methods. A full scale MBR's membrane life-time was assessed on the following: (i) maintaining the permeate flow throughput to the MBR; (ii) the permeability decline; (iii) oxidative aging; (iv) the increase in energy costs; and (v) mechanical aging. The method based on permeability decline provides a membrane life-time estimate up to a theoretical end. It was further elaborated inherently to operations with no long-term flux decline. The increase in operating pressure remains the main end-of-life trigger for deciding when to replace membrane modules. On the contrary, mechanical and permeate flow throughput analysis of the data are not able to provide a clear estimate of the membrane life-time. As for the membrane life-time estimation based on chlorine contact, it was found to be too optimistic. Complete irreversible fouling occurs before maximum contact time with chlorine is reached. At end-of-life operating conditions, the energy consumption raised of 170% due to the reduced flow rate. The cost raise appears high but still affordable. Earlier membrane replacement thus can never be counterbalanced by energy costs saving. (C) 2012 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000308741100039 |
Publication Date |
2012-08-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
ISSN  |
0376-7388 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:101790 |
Serial |
7856 |
| Permanent link to this record |
| |
|
| |
| Author |
Sels, D.; Brosens, F.; Magnus, W. |
| Title |
On the path integral representation of the Wigner function and the BarkerMurray ansatz |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physics letters : A |
Abbreviated Journal |
Phys Lett A |
| Volume |
376 |
Issue |
6/7 |
Pages |
809-812 |
| Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
| Abstract |
The propagator of the Wigner function is constructed from the WignerLiouville equation as a phase space path integral over a new effective Lagrangian. In contrast to a paper by Barker and Murray (1983) [1], we show that the path integral can in general not be written as a linear superposition of classical phase space trajectories over a family of non-local forces. Instead, we adopt a saddle point expansion to show that the semiclassical Wigner function is a linear superposition of classical solutions for a different set of non-local time dependent forces. As shown by a simple example the specific form of the path integral makes the formulation ideal for Monte Carlo simulation. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000301167300005 |
Publication Date |
2012-01-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0375-9601; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.772 |
Times cited |
7 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.772; 2012 IF: 1.766 |
| Call Number |
UA @ lucian @ c:irua:94006 |
Serial |
2445 |
| Permanent link to this record |
| |
|
| |
| Author |
Michel, K.H.; Verberck, B. |
| Title |
Rigid-plane phonons in layered crystals |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
| Volume |
249 |
Issue |
12 |
Pages |
2604-2607 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The determination of the layer number ${\cal N}$ in nanoscale thin layered crystals is a challenging problem of technological relevance. In addition to innovative experimental techniques, a thorough knowledge of the underlying lattice dynamics is required. Starting from phenomenological atomic interaction potentials we have carried out an analytical study of the low-frequency optical phonon dispersions in layered crystals. At the gamma point of the two-dimensional Brillouin zone the optical phonon frequencies correspond to rigid-plane shearing and compression modes. We have investigated graphene multilayers (GML) and hexagonal boron-nitride multilayers (BNML). The frequencies show a characteristic dependence on ${\cal N}$. The results which are represented in the form of fan diagrams are very similar for both materials. Due to charge neutrality within layers Coulomb forces play no role, only van der Waals forces between nearest neighbor layers are relevant. The theoretical results agree with recent low-frequency Raman results on rigid-layer modes [Tan et al., Nature Mater. 11, 294 (2012)] in GML and double-resonant Raman scattering data on rigid-layer compression modes [Herziger et al., Phys. Rev. B 85, 235447 (2012)] in GML. (C) 2012 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
000312215300072 |
Publication Date |
2012-11-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0370-1972; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.674 |
Times cited |
1 |
Open Access |
|
| Notes |
; This work has been supported by the Flemish Science Foundation (FWO-Vl) and the Bijzonder Onderzoeksfonds, Universiteit Antwerpen (BOF-UA). ; |
Approved |
Most recent IF: 1.674; 2012 IF: 1.489 |
| Call Number |
UA @ lucian @ c:irua:105992 |
Serial |
2907 |
| Permanent link to this record |
| |
|
| |
| Author |
Cagno, S.; Favaretto, L.; Mendera, M.; Izmer, A.; Vanhaecke, F.; Janssens, K. |
| Title |
Evidence of early medieval soda ash glass in the archaeological site of San Genesio (Tuscany) |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Journal of archaeological science |
Abbreviated Journal |
J Archaeol Sci |
| Volume |
39 |
Issue |
5 |
Pages |
1540-1552 |
| Keywords |
A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The early medieval period marks an important turning point in the history of glassmaking, since it comprises the transition period between the mineral-based silica-soda-lime glass of the Roman tradition and the plant ash-based glass. With the aim of expanding the knowledge on the glass recipes and technologies of this period, 37 glass samples were analyzed, originating from the archaeological excavations of San Genesio (Tuscany) and dated from the fourth to the eleventh century. The major and minor element concentrations were measured with SEM-EDX, while the trace elements were quantified with LA-ICP-MS. The results were compared with published compositions of glass samples of similar age in order to highlight differences and similarities. The results offer a very interesting view on the glass circulation in the religious/residential/manufacturing center of San Genesio in the early medieval period. Most of the glass has a typical late-Roman composition, but some glass fragments are identified as soda ash glass. These are among the earliest medieval ash-fluxed glasses ever found in the Italian peninsula. (C) 2011 Elsevier Ltd. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000301620900034 |
Publication Date |
2012-01-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0305-4403 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.602 |
Times cited |
24 |
Open Access |
|
| Notes |
; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. ; |
Approved |
Most recent IF: 2.602; 2012 IF: 1.889 |
| Call Number |
UA @ admin @ c:irua:98251 |
Serial |
5618 |
| Permanent link to this record |
| |
|
| |
| Author |
Cagno, S.; Badano, M.B.; Mathis, F.; Strivay, D.; Janssens, K. |
| Title |
Study of medieval glass fragments from Savona (Italy) and their relation with the glass produced in Altare |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Journal of archaeological science |
Abbreviated Journal |
J Archaeol Sci |
| Volume |
39 |
Issue |
7 |
Pages |
2191-2197 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Altare was in the medieval and post-medieval period an important glassmaking center in the Liguria region in Northern Italy. The first historical evidence of glassmaking in Altare is dated to the twelfth century. In spite of that, due to the continuity of glassmaking up to the present time and the contemporaneous intensive urbanization of the territory, no medieval glass from Altare or its immediate vicinity has been analyzed up to now. In this work, glass from archaeological excavations in the center of Savona, city with close ties with the glassmaking center, was studied. Glass fragments, dated from the tenth to the sixteenth century were selected from the collections of the Archaeological Museum in Savona and non-destructively analyzed with quantitative PIXE-PIGE. The resulting compositions, compared with known glass productions of the same time and evaluated on the basis of historical documents, offer an interesting panorama on the variety of glass circulation in Liguria. (C) 2012 Elsevier Ltd. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000305849400027 |
Publication Date |
2012-03-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0305-4403 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.602 |
Times cited |
21 |
Open Access |
|
| Notes |
; This research was supported by the Interuniversity Attraction Poles Programme – Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. The authors gratefully acknowledge Prof. Carlo Varaldo for allowing the study of the glass preserved in the Archaeological Museum of Savona. ; |
Approved |
Most recent IF: 2.602; 2012 IF: 1.889 |
| Call Number |
UA @ admin @ c:irua:100332 |
Serial |
5849 |
| Permanent link to this record |
| |
|
| |
| Author |
Roelandts, T.; Batenburg, K.J.; Biermans, E.; Kübel, C.; Bals, S.; Sijbers, J. |
| Title |
Accurate segmentation of dense nanoparticles by partially discrete electron tomography |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
114 |
Issue |
|
Pages |
96-105 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
Accurate segmentation of nanoparticles within various matrix materials is a difficult problem in electron tomography. Due to artifacts related to image series acquisition and reconstruction, global thresholding of reconstructions computed by established algorithms, such as weighted backprojection or SIRT, may result in unreliable and subjective segmentations. In this paper, we introduce the Partially Discrete Algebraic Reconstruction Technique (PDART) for computing accurate segmentations of dense nanoparticles of constant composition. The particles are segmented directly by the reconstruction algorithm, while the surrounding regions are reconstructed using continuously varying gray levels. As no properties are assumed for the other compositions of the sample, the technique can be applied to any sample where dense nanoparticles must be segmented, regardless of the surrounding compositions. For both experimental and simulated data, it is shown that PDART yields significantly more accurate segmentations than those obtained by optimal global thresholding of the SIRT reconstruction. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000301954300011 |
Publication Date |
2012-01-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
34 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:97710 |
Serial |
52 |
| Permanent link to this record |
| |
|
| |
| Author |
van den Broek, W.; Rosenauer, A.; Goris, B.; Martinez, G.T.; Bals, S.; Van Aert, S.; van Dyck, D. |
| Title |
Correction of non-linear thickness effects in HAADF STEM electron tomography |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
116 |
Issue |
|
Pages |
8-12 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
In materials science, high angle annular dark field scanning transmission electron microscopy is often used for tomography at the nanometer scale. In this work, it is shown that a thickness dependent, non-linear damping of the recorded intensities occurs. This results in an underestimated intensity in the interior of reconstructions of homogeneous particles, which is known as the cupping artifact. In this paper, this non-linear effect is demonstrated in experimental images taken under common conditions and is reproduced with a numerical simulation. Furthermore, an analytical derivation shows that these non-linearities can be inverted if the imaging is done quantitatively, thus preventing cupping in the reconstruction. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000304473700002 |
Publication Date |
2012-03-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
67 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:96558 |
Serial |
518 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. |
| Title |
Direct structure inversion from exit waves : part 2 : a practical example |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
116 |
Issue |
|
Pages |
77-85 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
This paper is the second part of a two-part paper on direct structure inversion from exit waves. In the first part, a method has been proposed to quantitatively determine structure parameters with atomic resolution such as atom column positions, surface profile and the number of atoms in the atom columns. In this part, the theory will be demonstrated by means of a Au[110] exit wave reconstructed from a set of focal-series images. The procedures to analyze the experimentally reconstructed exit wave in terms of quantitative structure information are described in detail. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000304473700011 |
Publication Date |
2012-03-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:96660 |
Serial |
724 |
| Permanent link to this record |
| |
|
| |
| Author |
Goris, B.; van den Broek, W.; Batenburg, K.J.; Heidari Mezerji, H.; Bals, S. |
| Title |
Electron tomography based on a total variation minimization reconstruction technique |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
113 |
Issue |
|
Pages |
120-130 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
The 3D reconstruction of a tilt series for electron tomography is mostly carried out using the weighted backprojection (WBP) algorithm or using one of the iterative algorithms such as the simultaneous iterative reconstruction technique (SIRT). However, it is known that these reconstruction algorithms cannot compensate for the missing wedge. Here, we apply a new reconstruction algorithm for electron tomography, which is based on compressive sensing. This is a field in image processing specialized in finding a sparse solution or a solution with a sparse gradient to a set of ill-posed linear equations. Therefore, it can be applied to electron tomography where the reconstructed objects often have a sparse gradient at the nanoscale. Using a combination of different simulated and experimental datasets, it is shown that missing wedge artefacts are reduced in the final reconstruction. Moreover, it seems that the reconstructed datasets have a higher fidelity and are easier to segment in comparison to reconstructions obtained by more conventional iterative algorithms. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000300554400006 |
Publication Date |
2011-11-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
171 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:93637 |
Serial |
987 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Béché, A.; van den Broek, W. |
| Title |
A holographic method to measure the source size broadening in STEM |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
120 |
Issue |
|
Pages |
35-40 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Source size broadening is an important resolution limiting effect in modern STEM experiments. Here, we propose an alternative method to measure the source size broadening making use of a holographic biprism to create interference patterns in an empty Ronchigram. This allows us to measure the exact shape of the source size broadening with a much better sampling than previously possible. We find that the shape of the demagnified source deviates considerably from a Gaussian profile that is often assumed. We fit the profile with a linear combination of a Gaussian and a bivariate Cauchy distribution showing that even though the full width at half maximum is similar to previously reported measurements, the tails of the profile are considerable wider. This is of fundamental importance for quantitative comparison of STEM simulations with experiments as these tails make the image contrast dependent on the interatomic distance, an effect that cannot be reproduced by a single Gaussian profile of fixed width alone. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000308082600005 |
Publication Date |
2012-06-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
29 |
Open Access |
|
| Notes |
This work was supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 246791 COUNTATOMS and ERC Starting Grant 278510 VORTEX. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. W. Van den Broek acknowledges funding from the Condor project, a project under the supervision of the Embedded Systems Institute (ESI) and FEI. This project is partially supported by the Dutch Ministry of Economic Affairs under the BSIK program. ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:100466UA @ admin @ c:irua:100466 |
Serial |
1483 |
| Permanent link to this record |
| |
|
| |
| Author |
Lobato, I.; van Dyck, D. |
| Title |
Improved multislice calculations for including higher-order Laue zones effects |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
119 |
Issue |
|
Pages |
63-71 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
A new method for including higher-order Laue zones (HOLZs) effects in an efficient way in electron scattering simulations has been developed and tested by detail calculations. The calculated results by the conventional multislice (CMS) method and the improved conventional multislice (ICMS) method using a large dynamical aperture to avoid numerical errors are compared with accurate results. We have found that the zero-order Laue zones (ZOLZs) reflection cannot be properly described only using the projected potential in the whole unit cell; in general, we need to subslice the electrostatic potential inside the unit cell. It is shown that the ICMS method has higher accuracy than the CMS method for the calculation of the ZOLZ, HOLZ and Pseudo-HOLZ reflections. Hence, ICMS method allows to use a larger slice thickness than the CMS method and reduces the calculation time. (C) 2012 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000308079200011 |
Publication Date |
2012-01-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
6 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:101902 |
Serial |
1567 |
| Permanent link to this record |
| |
|
| |
| Author |
Verbeeck, J.; Tian, H.; Béché, A. |
| Title |
A new way of producing electron vortex probes for STEM |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
113 |
Issue |
|
Pages |
83-87 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A spiral holographic aperture is used in the condensor plane of a scanning transmission electron microscope to produce a focussed electron vortex probe carrying a topological charge of either −1, 0 or +1. The spiral aperture design has a major advantage over the previously used forked aperture in that the three beams with topological charge m=−1, 0, and 1 are not side by side in the specimen plane, but rather on top of each other, focussed at different heights. This allows us to have only one selected beam in focus on the sample while the others contribute only to a background signal. In this paper we describe the working principle as well as first experimental results demonstrating atomic resolution HAADF STEM images obtained with electron vortex probes. These results pave the way for atomic resolution magnetic information when combined with electron energy loss spectroscopy. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000300554400002 |
Publication Date |
2011-10-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
62 |
Open Access |
|
| Notes |
J.V. wants to thank Miles Padgett for suggesting this setup and pointing to the relevant optics literature. Peter Schattschneider is acknowledged for in depth discussions on related topics. J.V acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant no. 46791-COUN-TATOMS and ERC Starting Grant no. 278510 VORTEX. The Qu-Ant-EM microscope is partially funded by the Hercules fund of the Flemish Government. ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:93624UA @ admin @ c:irua:93624 |
Serial |
2336 |
| Permanent link to this record |
| |
|
| |
| Author |
Tan, H.; Verbeeck, J.; Abakumov, A.; Van Tendeloo, G. |
| Title |
Oxidation state and chemical shift investigation in transition metal oxides by EELS |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
116 |
Issue |
|
Pages |
24-33 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Transition metal L2,3 electron energy-loss spectra for a wide range of V-, Mn- and Fe-based oxides were recorded and carefully analyzed for their correlation with the formal oxidation states of the transition metal ions. Special attention is paid to obtain an accurate energy scale which provides absolute energy positions for all core-loss edges. The white-line ratio method, chemical shift method, ELNES fitting method, two-parameter method and other methods are compared and their validity is discussed. Both the ELNES fitting method and the chemical shift method have the advantage of a wide application range and good consistency but require special attention to accurately measure the core-loss edge position. The obtained conclusions are of fundamental importance, e.g., for obtaining atomic resolution oxidation state information in modern experiments. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000304473700004 |
Publication Date |
2012-03-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
413 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:96959UA @ admin @ c:irua:96959 |
Serial |
2541 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, A.; Van Aert, S.; Goos, P.; van Dyck, D. |
| Title |
Precision of three-dimensional atomic scale measurements from HRTEM images : what are the limits? |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
114 |
Issue |
|
Pages |
20-30 |
| Keywords |
A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
In this paper, we investigate to what extent high resolution transmission electron microscopy images can be used to measure the mass, in terms of thickness, and surface profile, corresponding to the defocus offset, of an object at the atomic scale. Therefore, we derive an expression for the statistical precision with which these object parameters can be estimated in a quantitative analysis. Evaluating this expression as a function of the microscope settings allows us to derive the optimal microscope design. Acquiring three-dimensional structure information in terms of thickness turns out to be much more difficult than obtaining two-dimensional information on the projected atom column positions. The attainable precision is found to be more strongly affected by processes influencing the image contrast, such as phonon scattering, than by the specific choice of microscope settings. For a realistic incident electron dose, it is expected that atom columns can be distinguished with single atom sensitivity up to a thickness of the order of the extinction distance. A comparable thickness limit is determined to measure surface steps of one atom. An increase of the electron dose shifts the limiting thickness upward due to an increase in the signal-to-noise ratio. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000301954300003 |
Publication Date |
2012-01-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
5 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:94116 |
Serial |
2692 |
| Permanent link to this record |
| |
|
| |
| Author |
Schattschneider, P.; Stöger-Pollach, M.; Löffler, S.; Steiger-Thirsfeld, A.; Hell, J.; Verbeeck, J. |
| Title |
Sub-nanometer free electrons with topological charge |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
115 |
Issue |
|
Pages |
21-25 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The holographic mask technique is used to create freely moving electrons with quantized angular momentum. With electron optical elements they can be focused to vortices with diameters below the nanometer range. The understanding of these vortex beams is important for many applications. Here, we produce electron vortex beams and compare them to a theory of electrons with topological charge. The experimental results show excellent agreement with simulations. As an immediate application, fundamental experimental parameters like spherical aberration and partial coherence are determined. (C) 2012 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000302962400004 |
Publication Date |
2012-01-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
24 |
Open Access |
|
| Notes |
vortex ECASJO_; |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
| Call Number |
UA @ lucian @ c:irua:98279 |
Serial |
3344 |
| Permanent link to this record |
| |
|
| |
| Author |
Maes, D.; Van Passel, S. |
| Title |
Interference of regional support policies on the economic and environmental performance of a hybrid cogeneration-solar panel energy system |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Energy Policy |
Abbreviated Journal |
Energ Policy |
| Volume |
42 |
Issue |
|
Pages |
670-680 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM) |
| Abstract |
This paper assesses unintentional interference between different public policies promoting energy efficiency and renewable energy. The paper develops a methodology to study the interference by analysing the economic and technical behaviour of a hybrid energy system. The hybrid energy system in this case consists of an existing cogeneration unit extended with a new installation of thermal solar panels. This puts two complementary heating technologies in juxtaposition. The two technologies are supported with distinct regional support instruments in each region. The design and operation of the energy system is optimised from the point of view of the investor according to the different support instruments. The optimal configuration is analysed as well as its effect on reduced CO2-emissions during the lifetime of the project. The methodology is applied to a case-study for two neighbouring regions, the Netherlands and Flanders. The policies in the Netherlands show a beneficial synergy. In Flanders, the hybrid energy system is not interesting, indicating unbalanced high support for cogeneration in this case. From the point of view of the authorities, a more balanced regional policy as in the Netherlands provides a larger CO2-emission reduction for a smaller cost. (C) 2012 Elsevier Ltd. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000301616000066 |
Publication Date |
2012-01-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0301-4215; 1873-6777 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.14 |
Times cited |
4 |
Open Access |
|
| Notes |
; The authors would especially like to thank Davy Duelen for the excellent case-study and data collection that enabled the present paper. The help and information provided by Pierre Gijsen also made the detailed assessment possible. We are also indebted to two anonymous reviewers, whose remarks strongly improved the paper. This project has been financed by the Impulse-project of the tUL (transnational University Limburg). ; |
Approved |
Most recent IF: 4.14; 2012 IF: 2.743 |
| Call Number |
UA @ admin @ c:irua:127558 |
Serial |
6220 |
| Permanent link to this record |
| |
|
| |
| Author |
De Keersmaecker, M.; De Wael, K.; Adriaens, A. |
| Title |
The use of lead dodecanoate as an environmentally friendly coating to inhibit the corrosion of lead objects : comparison of three different deposition methods |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Progress in organic coatings |
Abbreviated Journal |
Prog Org Coat |
| Volume |
74 |
Issue |
1 |
Pages |
1-7 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
An aqueous sodium dodecanoate solution has been used for the formation of a protective coating for lead. Three deposition methods have been compared: immobilization using cyclic voltammetry, immersion and amperometry. Apart from this, we tested a reduction pretreatment of the lead surface (−1.5 V during 600 s) in order to obtain a more reproducible coating, resulting in a better corrosion protection behavior. The corrosion inhibition properties were examined using potentiodynamic polarization curves and electrochemical impedance measurements in a standard corrosive environment. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000302585300001 |
Publication Date |
2012-02-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0300-9440; 0033-0655 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.858 |
Times cited |
8 |
Open Access |
|
| Notes |
; The Research Foundation – Flanders (FWO) and Ghent University are acknowledged for funding this work. The authors would like to thank Pieter Van Hoe for the production of the embedded lead electrodes. They also acknowledge Pieter Arickx and Jonas Van Damme for their contribution. ; |
Approved |
Most recent IF: 2.858; 2012 IF: 1.848 |
| Call Number |
UA @ admin @ c:irua:96354 |
Serial |
5894 |
| Permanent link to this record |
| |
|
| |
| Author |
Hellar-Kihampa, H.; Potgieter-Vermaak, S.; van Meel, K.; Gatto Rotondo, G.; Kishimba, M.; Van Grieken, R. |
| Title |
Elemental composition of bottom-sediments from Pangani river basin, Tanzania : lithogenic and anthropogenic sources |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Toxicological and environmental chemistry |
Abbreviated Journal |
|
| Volume |
94 |
Issue |
3 |
Pages |
525-544 |
| Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
River-bed sediments from the Pangani basin, Tanzania, were characterized for elemental compositions, following contamination risks from rapid expansions of human activities in the area. Samples were collected during two individual seasons and analyzed by high-polarizing beam energy dispersive X-ray fluorescence (EDXRF) for eight major and 14 trace elements. Evaluation of enrichment factors (EFs) was used to investigate the elemental flux and assess the contributions of natural and anthropogenic influences. The abundances of the major elements followed the order Si > Al > Fe > Ca > K > Ti > Mn > P, similar to that of the upper earth's crust, and were generally from the weathering of the bed-rock. The high concentrations of typical anthropogenic trace-elements (Cr < 160 mg kg−1, V < 85 mg kg−1, Ni < 60 mg kg−1, Cu < 87 mg kg−1, La < 90 mg kg−1) coupled with high EFs (>2) in some locations indicated contamination associated with agricultural and industrial activities. Factor analysis extracted five principal components that contributed to 96.0% of the total observed variance. The results indicated that river-bed sediments of the Pangani basin were influenced to a larger extent by lithogenic sources than anthropogenic impacts. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000304276100007 |
Publication Date |
2012-01-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0277-2248 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:97080 |
Serial |
7889 |
| Permanent link to this record |
| |
|
| |
| Author |
Özen, M.; Mertens, M.; Luyten, J.; Snijkers, F.; d' Hondt, H.; Cool, P. |
| Title |
Hydrothermal synthesis of carbonate-free submicron-sized barium titanate from an amorphous precursor : synthesis and characterization |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Ceramics international |
Abbreviated Journal |
Ceram Int |
| Volume |
38 |
Issue |
1 |
Pages |
619-625 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
| Abstract |
In this paper, the amorphous barium titanate precursor was prepared by the peroxo-hydroxide method and post-treated by various drying procedures, such as: room temperature drying, room temperature vacuum drying and vacuum drying at 50 degrees C. The objective in the latter two treatments was to increase the Ti-O-Ba bonds of the precursor. The post-treated precursors were compared with the untreated (i.e., 'wet') precursor. Also, a barium titanate precursor was prepared by an alkoxide route. Afterwards, the precursors were hydrothermally treated at 200 degrees C in a 10 M NaOH solution. Vacuum drying of the precursor seemingly promoted the formation of Ti-O-Ti bonds in the hydrothermal end-product. The low Ba:Ti ratio (0.66) of the alkoxide-route prepared precursor lead to a multi-phase hydrothermal product with BaTiO(3) as the main phase. In contrast, phase pure BaTiO(3), i.e. without BaCO(3) contamination, was obtained for the precursor which was dried at room temperature. Cube-shaped and highly crystalline BaTiO(3) particles were observed by electron microscopy for the hydrothermally treated peroxo-hydroxide-route prepared precursor. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Barking |
Editor |
|
| Language |
|
Wos |
000298766900083 |
Publication Date |
2011-08-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0272-8842; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.986 |
Times cited |
14 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.986; 2012 IF: 1.789 |
| Call Number |
UA @ lucian @ c:irua:96263 |
Serial |
1541 |
| Permanent link to this record |
| |
|
| |
| Author |
Potgieter-Vermaak, S.; Rotondo, G.; Novacovic, V.; Rollins, S.; Van Grieken, R. |
| Title |
Component-specific toxic concerns of the inhalable fraction of urban road dust |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Environmental geochemistry and health |
Abbreviated Journal |
|
| Volume |
34 |
Issue |
6 |
Pages |
689-696 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Continuous global urbanisation causes an ever-growing ecological footprint of pollution. Road dust (RD), one of these pollutants, poses a health concern due to carcinogenic and toxic components potentially present in the micron-sized fractions. The literature reports on the concentrations of trace, toxic metals and metalloids present in RD (Hooker and Nathanail in Chem Geol 226:340-351, 2006), but the literature on its molecular composition is limited. Recent reports on the bioaccessibility of platinum group metals are also reported (Colombo et al. in Chem Geol 226:340-351, 2008). In vitro and animal toxicological studies confirmed that the chemical composition of inhaled particles plays a major role in its toxic, genotoxic and carcinogenic mechanisms, but the component-specific toxic effects are still not understood. Particle-bound airborne transition metals can also lead to the production of reactive oxygen species in lung tissue; a special concern amongst particularly susceptible cohorts (children and elderly). The characterisation of the molecular composition of the fine fraction is evidently of importance for public health. During a pilot study, partially characterised size-fractioned RD samples (Barrett et al. in Eviron Sci Technol 44:2940-2946, 2010) were analysed for their elemental concentration using X-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry. In addition, separately dispersed particles (200 particles per size fraction) were analysed individually by means of computer-controlled electron probe X-ray micro-analysis (CC-EPXMA) and their molecular structure probed by studying elemental associations. These were correlated with micro-Raman spectroscopy (MRS) results. It was found that the fine fraction (< 38 mu m) had the highest Pb (238 ppm) and Cr (171 ppm) concentrations. The CC-EPXMA data showed > 50 % association of Cr-rich particles with Pb, and the MRS data showed that the Cr was mostly present as lead chromate and therefore in the Cr(VI) oxidation state. Concentrations of both Pb and Cr decreased substantially (279 (< 38 mu m)-13 ppm (< 1 mm); 171 (< 38 mu m)-91 ppm (< 1 mm), respectively) in the larger fractions. Apart from rather alarmingly high concentrations of oxidative stressors (Cu, Fe, Mn), the carcinogenic and toxic potential of the inhalable fraction is evident. Preliminary bioaccessibility data indicated that both Cr and Pb are readily mobilised in artificial lysosomal liquid and up to 19 % of Cr and 47 % of Pb were released. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000310540300005 |
Publication Date |
2012-09-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0269-4042 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:102135 |
Serial |
7699 |
| Permanent link to this record |
| |
|
| |
| Author |
Aghaei, M.; Lindner, H.; Bogaerts, A. |
| Title |
Effect of a mass spectrometer interface on inductively coupled plasma characteristics : a computational study |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Journal of analytical atomic spectrometry |
Abbreviated Journal |
J Anal Atom Spectrom |
| Volume |
27 |
Issue |
4 |
Pages |
604-610 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
An inductively coupled plasma connected to a mass spectrometer interface (sampling cone) is computationally investigated. Typical plasma characteristics, such as gas flow velocity, plasma temperature and electron density, are calculated in two dimensions (cylindrical symmetry) and compared with and without a mass spectrometer sampling interface. The results obtained from our model compare favorably with experimental data reported in the literature. A dramatic increase in the plasma velocity is reported in the region close to the interface. Furthermore, a cooled metal interface lowers the plasma temperature and electron density on the axial channel very close to the sampling cone but the corresponding values in the off axial regions are increased. Therefore, the effect of the interface strongly depends on the measurement position. It is shown that even a small shift from the actual position of the sampler leads to a considerable change of the results. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000301496700005 |
Publication Date |
2012-02-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0267-9477;1364-5544; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.379 |
Times cited |
18 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.379; 2012 IF: 3.155 |
| Call Number |
UA @ lucian @ c:irua:97386 |
Serial |
791 |
| Permanent link to this record |
| |
|
| |
| Author |
Navío, C.; Vallejos, S.; Stoycheva, T.; Llobet, E.; Correig, X.; Snyders, R.; Blackman, C.; Umek, P.; Ke, X.; Van Tendeloo, G.; Bittencourt, C.; |
| Title |
Gold clusters on WO3 nanoneedles grown via AACVD : XPS and TEM studies |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Materials chemistry and physics |
Abbreviated Journal |
Mater Chem Phys |
| Volume |
134 |
Issue |
2/3 |
Pages |
809-813 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We have prepared tungsten oxide films decorated with gold particles on Si substrates by aerosol assisted chemical vapor deposition (AACVD) and characterized them using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). SEM shows that the films are composed of needle-like structures and TEM shows that both the needles and the gold particles are crystalline. XPS indicates the presence of oxygen vacancies, i.e. the films are WO3−x, and hence the deposited material is composed of semiconducting nanostructures and that the interaction between the gold particles and the WO3 needles surface is weak. The synthesis of semiconducting tungsten oxide nanostructures decorated with metal particles represents an important step towards the development of sensing devices with optimal properties. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
| Language |
|
Wos |
000305918200038 |
Publication Date |
2012-04-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0254-0584; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.084 |
Times cited |
52 |
Open Access |
|
| Notes |
Iap |
Approved |
Most recent IF: 2.084; 2012 IF: 2.072 |
| Call Number |
UA @ lucian @ c:irua:97705 |
Serial |
1356 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Passel, S.; Meul, M. |
| Title |
Multilevel and multi-user sustainability assessment of farming systems |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Environmental Impact Assessment Review |
Abbreviated Journal |
Environ Impact Asses |
| Volume |
32 |
Issue |
1 |
Pages |
170-180 |
| Keywords |
A1 Journal article; Engineering sciences. Technology |
| Abstract |
Sustainability assessment is needed to build sustainable farming systems. A broad range of sustainability concepts, methodologies and applications already exists. They differ in level, focus, orientation, measurement, scale, presentation and intended end-users. In this paper we illustrate that a smart combination of existing methods with different levels of application can make sustainability assessment more profound, and that it can broaden the insights of different end-user groups. An overview of sustainability assessment tools on different levels and for different end-users shows the complementarities and the opportunities of using different methods. In a case-study, a combination of the sustainable value approach (SVA) and MOTIFS is used to perform a sustainability evaluation of farming systems in Flanders. SVA is used to evaluate sustainability at sector level, and is especially useful to support policy makers, while MOTIFS is used to support and guide farmers towards sustainability at farm level. The combined use of the two methods with complementary goals can widen the insights of both farmers and policy makers, without losing the particularities of the different approaches. To stimulate and support further research and applications, we propose guidelines for multilevel and multi-user sustainability assessments. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000297874000020 |
Publication Date |
2011-09-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0195-9255 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.094 |
Times cited |
49 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.094; 2012 IF: 1.851 |
| Call Number |
UA @ admin @ c:irua:94186 |
Serial |
6231 |
| Permanent link to this record |
| |
|
| |
| Author |
Carniato, L.; Schoups, G.; Seuntjens, P.; Van Nooten, T.; Simons, Q.; Bastiaens, L. |
| Title |
Predicting longevity of iron permeable reactive barriers using multiple iron deactivation models |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Journal of contaminant hydrology |
Abbreviated Journal |
|
| Volume |
142 |
Issue |
|
Pages |
93-108 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
In this study we investigate the model uncertainties involved in predicting long-term permeable reactive barrier (PRB) remediation efficiency based on a lab-scale column experiment under accelerated flow conditions. A PRB consisting of 20% iron and 80% sand was simulated in a laboratory-scale column and contaminated groundwater was pumped into the column for approximately 1 year at an average groundwater velocity of 3.7E – 1 m d(-1). Dissolved contaminants (PCE. TCE, cis-DCE, trans-DCE and VC) and inorganic (Ca2+, Fe2+, TIC and pH) concentrations were measured in groundwater sampled at different times and at eight different distances along the column. These measurements were used to calibrate a multi-component reactive transport model, which subsequently provided predictions of long-term PRB efficiency under reduced flow conditions (i.e., groundwater velocity of 1.4E -3 m d(-1)), representative of a field site of interest in this study. Iron reactive surface reduction due to mineral precipitation and iron dissolution was simulated using four different models. All models were able to reasonably well reproduce the column experiment measurements, whereas the extrapolated long-term efficiency under different flow rates was significantly different between the different models. These results highlight significant model uncertainties associated with extrapolating long-term PRB performance based on lab-scale column experiments. These uncertainties should be accounted for at the PRB design phase, and may be reduced by independent experiments and field observations aimed at a better understanding of reactive surface deactivation mechanisms in iron PRBs. (C) 2012 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000312753000009 |
Publication Date |
2012-09-13 |
| 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 |
|
| ISSN |
0169-7722 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:106010 |
Serial |
8402 |
| Permanent link to this record |
| |
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| |
| Author |
Piñera, I.; Cruz, C.M.; van Espen, P.; Abreu, Y.; Leyva, A. |
| Title |
Study of dpa distributions in electron irradiated YBCO slabs through MCCM algorithm |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms |
Abbreviated Journal |
|
| Volume |
274 |
Issue |
|
Pages |
191-194 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The Monte Carlo assisted Classical Method (MCCM) consists on a calculation procedure for determining the displacements per atom (dpa) distribution in solid materials. This algorithm allows studying the gamma and electron irradiation damage in different materials. It is based on the electrons elastic scattering classic theories and the use of Monte Carlo simulation for the physical processes involved. The present study deals with the Monte Carlo simulation of electron irradiation effects on YBa2Cu3O7-x (YBCO) slabs using the MCNPX code system. Displacements per atom distributions are obtained through the MCCM for electron irradiation up to 10 MeV. In-depth dpa profiles for electrons and positrons are obtained and analysed. Also, dpa contributions from each atomic specie in the material are calculated. It was found that the dpa distribution is more homogeneous in the material volume when increasing energy of incident electrons. Also, the dpa produced by positrons has no relevance when irradiating with electrons, in contrast with previous similar gamma irradiation studies. All the results are presented and discussed in this contribution. (C) 2011 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000301611900031 |
Publication Date |
2011-12-05 |
| 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 |
0168-583x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:97819 |
Serial |
8595 |
| Permanent link to this record |
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| |
| Author |
Mishra, V.K.; Kumar, P.; Van Poppel, M.; Bleux, N.; Frijns, E.; Reggente, M.; Berghmans, P.; Int Panis, L.; Samson, R. |
| Title |
Wintertime spatio-temporal variation of ultrafine particles in a Belgian city |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
The science of the total environment |
Abbreviated Journal |
|
| Volume |
431 |
Issue |
|
Pages |
307-313 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Simultaneous measurements of ultrafine particles (UFPs) were carried out at four sampling locations situated within a 1 km(2) grid area in a Belgian city, Borgerhout (Antwerp). All sampling sites had different orientation and height of buildings and dissimilar levels of anthropogenic activities (mainly traffic volume). The aims were to investigate: (i) the spatio-temporal variation of UFP within the area, (ii) the effect of wind direction with respect to the volume of traffic on UFP levels, and (iii) the spatial representativeness of the official monitoring station situated in the study area. All sampling sites followed similar diurnal patterns of UFP variation, but effects of local traffic emissions were evident. Wind direction also had a profound influence on UFP concentrations at certain sites. The results indicated a clear influence of local weather conditions and the more dominant effect of traffic volumes. Our analysis indicated that the regional air quality monitoring station represented the other sampling sites in the study area reasonably well; temporal patterns were found to be comparable though the absolute average concentrations showed differences of up to 35%. (C) 2012 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000306887900037 |
Publication Date |
2012-06-14 |
| 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 |
|
| ISSN |
0048-9697; 1879-1026 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:101123 |
Serial |
8759 |
| Permanent link to this record |
| |
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| |
| Author |
Haest, P.J.; Springael, D.; Seuntjens, P.; Smolders, E. |
| Title |
Self-inhibition can limit biologically enhanced TCE dissolution from a TCE DNAPL |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Chemosphere |
Abbreviated Journal |
|
| Volume |
89 |
Issue |
11 |
Pages |
1369-1375 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Biodegradation of trichloroethene (TCE) near a Dense Non Aqueous Phase Liquid (DNAPL) can enhance the dissolution rate of the DNAPL by increasing the concentration gradient at the DNAPL-water interface. Two-dimensional flow-through sand boxes containing a ICE DNAPL and inoculated with a TCE dechlorinating consortium were set up to measure this bio-enhanced dissolution under anaerobic conditions. The total mass of TCE and daughter products in the effluent of the biotic boxes was 3-6 fold larger than in the effluent of the abiotic box. However, the mass of daughter products only accounted for 19-55% of the total mass of chlorinated compounds in the effluent, suggesting that bio-enhanced dissolution factors were maximally 1.3-2.2. The enhanced dissolution most likely primarily resulted from variable DNAPL distribution rather than biodegradation. Specific dechlorination rates previously determined in a stirred liquid medium were used in a reactive transport model to identify the rate limiting factors. The model adequately simulated the overall TCE degradation when predicted resident microbial numbers approached observed values and indicated an enhancement factor for TCE dissolution of 1.01. The model shows that dechlorination of TCE in the 20 box was limited due to the short residence time and the self-inhibition of the TCE degradation. A parameter sensitivity analysis predicts that the bio-enhanced dissolution factor for this TCE source zone can only exceed a value of 2 if the TCE self-inhibition is drastically reduced (when a TCE tolerant dehalogenating community is present) or if the DNAPL is located in a low-permeable layer with a small Darcy velocity. (C) 2012 Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000310112600015 |
Publication Date |
2012-06-30 |
| 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 |
0045-6535; 1879-1298 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:102142 |
Serial |
8512 |
| Permanent link to this record |
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| |
| Author |
Anaf, W.; Horemans, B.; Van Grieken, R.; De Wael, K. |
| Title |
Chemical boundary conditions for the classification of aerosol particles using computer controlled electron probe microanalysis |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Talanta : the international journal of pure and applied analytical chemistry |
Abbreviated Journal |
Talanta |
| Volume |
101 |
Issue |
|
Pages |
420-427 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A method for the classification of individual aerosol particles using computer controlled electron probe microanalysis is presented. It is based on chemical boundary conditions (CBC) and enables quick and easy processing of a large set of elemental concentration data (mass%), derived from the X-ray spectra of individual particles. The particles are first classified into five major classes (sea salt related, secondary inorganic, minerals, iron-rich and carbonaceous), after which advanced data mining can be performed by examining the elemental composition of particles within each class into more detail (e.g., by ternary diagrams). The CBC method is validated and evaluated by comparing its results with the output obtained with hierarchical cluster analysis (HCA) for well-known standard particles as well as real aerosol particles collected with a cascade impactor. The CBC method gives reliable results and has a major advantage compared to HCA. CBC is based on boundary conditions that are derived from chemical logical thinking and does not require a translation of a mathematical algorithm output as does HCA. Therefore, the CBC method is more objective and enables comparison between samples without intermediate steps. |
| 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 |
000313084400061 |
Publication Date |
2012-09-30 |
| 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 |
0039-9140; 1873-3573 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.162 |
Times cited |
3 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 4.162; 2012 IF: 3.498 |
| Call Number |
UA @ admin @ c:irua:101336 |
Serial |
5511 |
| Permanent link to this record |
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| Author |
Kao, K.-H.; Verhulst, A.S.; Vandenberghe, W.G.; Sorée, B.; Groeseneken, G.; De Meyer, K. |
| Title |
Modeling the impact of junction angles in tunnel field-effect transistors |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Solid state electronics |
Abbreviated Journal |
Solid State Electron |
| Volume |
69 |
Issue |
|
Pages |
31-37 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We develop an analytical model for a tunnel field-effect transistor (TFET) with a tilted source junction angle. The tunnel current is derived by using circular tunnel paths along the electric field. The analytical model predicts that a smaller junction angle improves the TFET performance, which is supported by device simulations. An analysis is also made based on straight tunnel paths and tunnel paths corresponding to the trajectory of a classical particle. In all the aforementioned cases, the same conclusions are obtained. A TFET configuration with an encroaching polygon source junction is studied to analyze the junction angle dependence at the smallest junction angles. The improvement of the subthreshold swing (SS) with decreasing junction angle can be achieved by using thinner effective oxide thickness, smaller band gap material and longer encroaching length of the encroaching junction. A TFET with a smaller junction angle on the source side also has an innate immunity against the degradation of the fringing field from the gate electrode via a high-k spacer. A large junction angle on the drain side can suppress the unwanted ambipolar current of TFETs. (c) 2011 Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Oxford |
Editor |
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| Language |
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Wos |
000301561600009 |
Publication Date |
2012-01-16 |
| 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 |
0038-1101; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.58 |
Times cited |
9 |
Open Access |
|
| Notes |
; We acknowledge the input on nanowire processing of Rita Rooyackers and useful discussions with Wim Magnus. William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was also supported by imec's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 1.58; 2012 IF: 1.482 |
| Call Number |
UA @ lucian @ c:irua:97816 |
Serial |
2145 |
| Permanent link to this record |
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| |
| Author |
Pham, A.-T.; Sorée, B.; Magnus, W.; Jungemann, C.; Meinerzhagen, B.; Pourtois, G. |
| Title |
Quantum simulations of electrostatics in Si cylindrical junctionless nanowire nFETs and pFETs with a homogeneous channel including strain and arbitrary crystallographic orientations |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Solid state electronics |
Abbreviated Journal |
Solid State Electron |
| Volume |
71 |
Issue |
|
Pages |
30-36 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Simulation results of electrostatics in Si cylindrical junctionless nanowire transistors with a homogenous channel are presented. Junctionless transistors including strain and arbitrary crystallographic orientations are studied. Size quantization effects are simulated by self-consistent solutions of the Poisson and Schrodinger equations. The 6 x 6 k.p method is employed for the calculation of the valence subband structure in a junctionless nanowire pFET. The influence of stress/strain and crystallographic channel orientation on to the electrostatics in terms of subband structure, charge density, and C-V curve is systematically studied. (C) 2011 Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Oxford |
Editor |
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| Language |
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Wos |
000303033800007 |
Publication Date |
2011-12-01 |
| 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 |
0038-1101; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.58 |
Times cited |
2 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.58; 2012 IF: 1.482 |
| Call Number |
UA @ lucian @ c:irua:98245 |
Serial |
2786 |
| Permanent link to this record |
