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Author Yang, X.-Y.; Tian, G.; Chen, L.-H.; Li, Y.; Rooke, J.C.; Wei, Y.-X.; Liu, Z.-M.; Deng, Z.; Van Tendeloo, G.; Su, B.-L.
Title Well-organized zeolite nanocrystal aggregates with interconnected hierarchically micro-meso-macropore systems showing enhanced catalytic performance Type A1 Journal article
Year 2011 Publication Chemistry: a European journal Abbreviated Journal Chem-Eur J
Volume 17 Issue 52 Pages 14987-14995
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Preparation and characterization of well-organized zeolitic nanocrystal aggregates with an interconnected hierarchically micromesomacro porous system are described. Amorphous nanoparticles in bimodal aluminosilicates were directly transformed into highly crystalline nanosized zeolites, as well as acting as scaffold template. All pores on three length scales incorporated in one solid body are interconnected with each other. These zeolitic nanocrystal aggregates with hierarchically micromesomacroporous structure were thoroughly characterized. TEM images and 29Si NMR spectra showed that the amorphous phase of the initial material had been completely replaced by nanocrystals to give a micromesomacroporous crystalline zeolitic structure. Catalytic testing demonstrated their superiority due to the highly active sites and the presence of interconnected micromesomacroporosity in the cracking of bulky 1,3,5-triisopropylbenzene (TIPB) compared to traditional zeolite catalysts. This synthesis strategy was extended to prepare various zeolitic nanocrystal aggregates (ZSM-5, Beta, TS-1, etc.) with well-organized hierarchical micromesomacroporous structures.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000298547300035 Publication Date 2011-11-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0947-6539; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.317 Times cited 61 Open Access
Notes Approved Most recent IF: 5.317; 2011 IF: 5.925
Call Number UA @ lucian @ c:irua:96274 Serial 3913
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Author Li, Y.; Tan, H.; Yang, X.-Y.; Goris, B.; Verbeeck, J.; Bals, S.; Colson, P.; Cloots, R.; Van Tendeloo, G.; Su, B.-L.
Title Well shaped Mn3O4 nano-octahedra with anomalous magnetic behavior and enhanced photodecomposition properties Type A1 Journal article
Year 2011 Publication Small Abbreviated Journal Small
Volume 7 Issue 4 Pages 475-483
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Very uniform and well shaped Mn3O4 nano-octahedra are synthesized using a simple hydrothermal method under the help of polyethylene glycol (PEG200) as a reductant and shape-directing agent. The nano-octahedra formation mechanism is monitored. The shape and crystal orientation of the nanoparticles is reconstructed by scanning electron microscopy and electron tomography, which reveals that the nano-octahedra only selectively expose {101} facets at the external surfaces. The magnetic testing demonstrates that the Mn3O4 nano-octahedra exhibit anomalous magnetic properties: the Mn3O4 nano-octahedra around 150 nm show a similar Curie temperature and blocking temperature to Mn3O4 nanoparticles with 10 nm size because of the vertical axis of [001] plane and the exposed {101} facets. With these Mn3O4 nano-octahedra as a catalyst, the photodecomposition of rhodamine B is evaluated and it is found that the photodecomposition activity of Mn3O4 nano-octahedra is much superior to that of commercial Mn3O4 powders. The anomalous magnetic properties and high superior photodecomposition activity of well shaped Mn3O4 nano-octahedra should be related to the special shape of the nanoparticles and the abundantly exposed {101} facets at the external surfaces. Therefore, the shape preference can largely broaden the application of the Mn3O4 nano-octahedra.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000288080400008 Publication Date 2011-01-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1613-6810; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.643 Times cited 131 Open Access
Notes This work was realized in the frame of an Interuniversity Attraction Poles Program (Inanomat-P6/17)-Belgian State-Belgian Science Policy and the project “Redugaz”, financially supported by the European community and the Wallon government in the frame of Interreg IV (France-Wallonie). B. L. S. acknowledges the Chinese Central Government for an “Expert of the State” position in the program of “Thousand talents” and the Chinese Ministry of Education for a Changjiang Scholar position at the Wuhan University of Technology. H. T. acknowledges the financial support from FWO-Vlaanderen (Project nr. G.0147.06). J.V. thanks the financial support from the European Union under Framework 6 program for Integrated Infrastructure Initiative, Reference 026019 ESTEEM. Approved Most recent IF: 8.643; 2011 IF: 8.349
Call Number UA @ lucian @ c:irua:87908 Serial 3914
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Author Guda, A.A.; Smolentsev, N.; Verbeeck, J.; Kaidashev, E.M.; Zubavichus, Y.; Kravtsova, A.N.; Polozhentsev, O.E.; Soldatov, A.V.
Title X-ray and electron spectroscopy investigation of the coreshell nanowires of ZnO:Mn Type A1 Journal article
Year 2011 Publication Solid state communications Abbreviated Journal Solid State Commun
Volume 151 Issue 19 Pages 1314-1317
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract ZnO/ZnO:Mn coreshell nanowires were studied by means of X-ray absorption spectroscopy of the Mn K- and L2,3-edges and electron energy loss spectroscopy of the O K-edge. The combination of conventional X-ray and nanofocused electron spectroscopies together with advanced theoretical analysis turned out to be fruitful for the clear identification of the Mn phase in the volume of the coreshell structures. Theoretical simulations of spectra, performed using the full-potential linear augmented plane wave approach, confirm that the shell of the nanowires, grown by the pulsed laser deposition method, is a real dilute magnetic semiconductor with Mn2+ atoms at the Zn sites, while the core is pure ZnO.
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Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000295492200003 Publication Date 2011-06-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.554 Times cited 12 Open Access
Notes We acknowledge the Helmholtz-Zentrum Berlin – Electron storage ring BESSY-II for provision of synchrotron radiation at the Russian-German beamline and financial support. This research was supported by the Russian Ministry to education and science (RPN 2.1.1. 5932 grant and RPN 2.1.1.6758 grant). N.S. and A.G. would like to thank the Russian Ministry of Education for providing the fellowships of President of Russian Federation to study abroad. We would like to thank the UGINFO computer center of Southern federal university for providing the computer time. Approved Most recent IF: 1.554; 2011 IF: 1.649
Call Number UA @ lucian @ c:irua:92831 Serial 3925
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Author Afanasov, I.M.; Van Tendeloo, G.
Title Zirconia-modified exfoliated graphite Type A1 Journal article
Year 2011 Publication Inorganic materials Abbreviated Journal Inorg Mater+
Volume 47 Issue 6 Pages 603-608
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Zirconia has been incorporated into exfoliated graphite (EG) through the anodic polarization in the natural graphite-ZrO(NO3)2-HNO3-H2O system, followed by flash heating. The thermal properties of the oxidized graphites employed as precursors to EG have been studied by thermogravimetry in combination with differential scanning calorimetry, and the distribution of ZrO2 particles in the EG has been assessed by scanning and transmission electron microscopy. Conditions are described for the preparation of EG with bulk densities in the range 1.34.7 g/l and ZrO2 contents in the range 434 wt %.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000291698100008 Publication Date 2011-05-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1685;1608-3172; ISBN Additional Links UA library record; WoS full record
Impact Factor 0.62 Times cited Open Access
Notes Approved Most recent IF: 0.62; 2011 IF: 0.414
Call Number UA @ lucian @ c:irua:90447 Serial 3933
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Author Esken, D.; Noei, H.; Wang, Y.; Wiktor, C.; Turner, S.; Van Tendeloo, G.; Fischer, R.A.
Title ZnO@ZIF-8 : stabilization of quantum confined ZnO nanoparticles by a zinc methylimidazolate framework and their surface structural characterization probed by CO2 adsorption Type A1 Journal article
Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 21 Issue 16 Pages 5907-5915
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The microporous and activated zeolitic imidazolate framework (Zn(MeIM)2; MeIM = imidazolate-2-methyl; ZIF-8) was loaded with the MOCVD precursor diethyl zinc [Zn(C2H5)2]. Exposure of ZIF-8 to the vapour of the volatile organometallic molecule resulted in the formation of the inclusion compound [Zn(C2H5)2]0.38@ZIF-8 revealing two precursor molecules per cavity. In a second step the obtained material was treated with oxygen (5 vol% in argon) at various temperatures (oxidative annealing) to achieve the composite material ZnO0.35@ZIF-8. The new material was characterized with powder XRD, FT-IR, UV-vis, solid state NMR, elemental analysis, N2 sorption measurements, and transmission electron microscopy. The data give evidence for the presence of nano-sized ZnO particles stabilized by ZIF-8 showing a blue-shift of the UV-vis absorption caused by quantum size effect (QSE). The surface structure and reactivity of embedded ZnO nanoparticles were characterized via carbon dioxide adsorption at different temperatures monitored by ultra-high vacuum FTIR techniques. It was found that the surface of ZnO nanoparticles is dominated by polar OZnO and ZnZnO facets as well as by defect sites, which all exhibit high reactivity towards CO2 activation forming various adsorbed carbonate and chemisorbed CO2δ− species.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000289260000012 Publication Date 2011-03-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0959-9428;1364-5501; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 76 Open Access
Notes Esteem 026019 Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:88641 Serial 3936
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Author Béché, A.; Rouvière, J.L.; Barnes, J.P.; Cooper, D.
Title Dark field electron holography for strain measurement Type A1 Journal article
Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy
Volume 111 Issue 3 Pages 227-238
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Dark field electron holography is a new TEM-based technique for measuring strain with nanometer scale resolution. Here we present the procedure to align a transmission electron microscope and obtain dark field holograms as well as the theoretical background necessary to reconstruct strain maps from holograms. A series of experimental parameters such as biprism voltage, sample thickness, exposure time, tilt angle and choice of diffracted beam are then investigated on a silicon-germanium layer epitaxially embedded in a silicon matrix in order to obtain optimal dark field holograms over a large field of view with good spatial resolution and strain sensitivity.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000288638200007 Publication Date 2010-12-01
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 31 Open Access
Notes Approved Most recent IF: 2.843; 2011 IF: 2.471
Call Number UA @ lucian @ c:irua:136368 Serial 4496
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Author Cooper, D.; de la Peña, F.; Béché, A.; Rouvière, J.-L.; Servanton, G.; Pantel, R.; Morin, P.
Title Field mapping with nanometer-scale resolution for the next generation of electronic devices Type A1 Journal article
Year 2011 Publication Nano letters Abbreviated Journal Nano Lett
Volume 11 Issue 11 Pages 4585-4590
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In order to improve the performance of todays nanoscaled semiconductor devices, characterization techniques that can provide information about the position and activity of dopant atoms and the strain fields are essential. Here we demonstrate that by using a modern transmission electron microscope it is possible to apply multiple techniques to advanced materials systems in order to provide information about the structure, fields, and composition with nanometer-scale resolution. Off-axis electron holography has been used to map the active dopant potentials in state-of-the-art semiconductor devices with 1 nm resolution. These dopant maps have been compared to electron energy loss spectroscopy maps that show the positions of the dopant atoms. The strain fields in the devices have been measured by both dark field electron holography and nanobeam electron diffraction.
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Corporate Author Thesis
Publisher Place of Publication Washington Editor
Language Wos 000296674700014 Publication Date 2011-10-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.712 Times cited 12 Open Access
Notes Approved Most recent IF: 12.712; 2011 IF: 13.198
Call Number UA @ lucian @ c:irua:136369 Serial 4499
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Author Cooper, D.; Rouvière, J.-L.; Béché, A.; Kadkhodazadeh, S.; Semenova, E.S.; Dunin-Borkowsk, R.
Title Quantitative strain mapping of InAs/InP quantum dots with 1 nm spatial resolution using dark field electron holography Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 99 Issue Pages 261911-261913
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The optical properties of semiconductor quantum dots are greatly influenced by their strain state. Dark field electron holography has been used to measure the strain in InAsquantum dotsgrown in InP with a spatial resolution of 1 nm. A strain value of 5.4% ± 0.1% has been determined which is consistent with both measurements made by geometrical phase analysis of high angle annular dark field scanning transmission electron microscopy images and with simulations.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000298638500027 Publication Date 2012-01-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; 1077-3118 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 26 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:136428 Serial 4507
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Author Denneulin, T.; Rouvière, J.L.; Béché, A.; Py, M.; Barnes, J.P.; Rochat, N.; Hartmann, J.M.; Cooper, D.
Title The reduction of the substitutional C content in annealed Si/SiGeC superlattices studied by dark-field electron holography Type A1 Journal article
Year 2011 Publication Semiconductor science and technology Abbreviated Journal Semicond Sci Tech
Volume 26 Issue 12 Pages 1-10
Keywords (down) A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Si/Si(1 − x − y)GexCy superlattices are used in the construction of new microelectronic architectures such as multichannel transistors. The introduction of carbon in SiGe allows for compensation of the strain and to avoid plastic relaxation. However, the formation of incoherent β-SiC clusters during annealing limits the processability of SiGeC. This precipitation leads to a modification of the strain in the alloy due to the reduction of the substitutional carbon content. Here, we investigated the strain in annealed Si/Si0.744Ge0.244C0.012 superlattices grown by reduced pressure chemical vapour deposition using dark-field electron holography. The variation of the substitutional C content was calculated by correlating the results with finite-element simulations. The obtained values were then compared with Fourier-transformed infrared spectrometry measurements. It was shown that after annealing for 2 min at 1050 °C carbon no longer has any influence on strain in the superlattice, which behaves like pure SiGe. However, a significant proportion of substitutional C atoms remain in a third-nearest neighbour (3nn) configuration. It was deduced that the influence of 3nn C on strain is negligible and that only isolated atoms have a significant contribution. It was also proposed that the 3nn configuration is an intermediary step during the formation of SiC clusters.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000300151300010 Publication Date 2011-11-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0268-1242 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.305 Times cited Open Access
Notes Approved Most recent IF: 2.305; 2011 IF: 1.723
Call Number UA @ lucian @ c:irua:136427 Serial 4508
Permanent link to this record
 
 
Author Ang, F.; Van Passel, S.; Mathijs, E.
Title An aggregate resource efficiency perspective on sustainability : a sustainable value application to the EU-15 countries Type A1 Journal article
Year 2011 Publication Ecological Economics Abbreviated Journal Ecol Econ
Volume 71 Issue Pages 99-110
Keywords (down) A1 Journal article; Economics
Abstract The Sustainable Value approach integrates the efficiency with regard to environmental, social and economic resources into a monetary indicator. It gained significant popularity as evidenced by diverse applications at the corporate level. However, its introduction as a measure adhering to the strong sustainability paradigm sparked an ardent debate. This study explores its validity as a macroeconomic strong sustainability measure by applying the Sustainable Value approach to the EU-15 countries. Concretely, we assessed environmental, social and economic resources in combination with the GDP for all EU-15 countries from 1995 to 2006 for three benchmark alternatives. The results show that several countries manage to adequately delink resource use from GDP growth. Furthermore, the remarkable difference in outcome between the national and EU-15 benchmark indicates a possible inefficiency of the current allocation of national resource ceilings imposed by the European institutions. Additionally, by using an effects model we argue that the service degree of the economy and governmental expenditures on social protection and research and development are important determinants of overall resource efficiency. Finally, we sketch out three necessary conditions to link the Sustainable Value approach to the strong sustainability paradigm. (C) 2011 Elsevier B.V. All rights reserved.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297396700011 Publication Date 2011-09-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-8009; 1873-6106 ISBN Additional Links UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles
Impact Factor 2.965 Times cited 12 Open Access
Notes ; ; Approved Most recent IF: 2.965; 2011 IF: 2.713
Call Number UA @ admin @ c:irua:127560 Serial 6151
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Author van Holsbeke, C.; de Backer, J.; Vos, W.; Verdonck, P.; van Ransbeeck, P.; Claessens, T.; Braem, M.; Vanderveken, O.; de Backer, W.
Title Anatomical and functional changes in the upper airways of sleep apnea patients due to mandibular repositioning: a large scale study Type A1 Journal article
Year 2011 Publication Journal of biomechanics Abbreviated Journal J Biomech
Volume 44 Issue 3 Pages 442-449
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW)
Abstract The obstructive sleep apnea-hypopnea syndrome (OSAHS) is a sleep related breathing disorder. A popular treatment is the use of a mandibular repositioning appliance (MRA) which advances the mandibula during the sleep and decreases the collapsibility of the upper airway. The success rate of such a device is, however, limited and very variable within a population of patients. Previous studies using computational fluid dynamics have shown that there is a decrease in upper airway resistance in patients who improve clinically due to an MRA. In this article, correlations between patient-specific anatomical and functional parameters are studied to examine how MRA induced biomechanical changes will have an impact on the upper airway resistance. Low-dose computed tomography (CT) scans are made from 143 patients suffering from OSAHS. A baseline scan and a scan after mandibular repositioning (MR) are performed in order to study variations in parameters. It is found that MR using a simulation bite is able to induce resistance changes by changing the pharyngeal lumen. The change in minimal cross-sectional area is the best parameter to predict the change in upper airway resistance. Looking at baseline values, the ideal patients for MR induced resistance decrease seem to be women with short airways, high initial resistance and no baseline occlusion.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000287551000014 Publication Date 2010-10-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9290; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.664 Times cited 23 Open Access
Notes ; ; Approved Most recent IF: 2.664; 2011 IF: 2.434
Call Number UA @ lucian @ c:irua:85305 Serial 112
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Author De Backer, L.A.; Vos, W.G.; Salgado, R.; de Backer, J.W.; Devolder, A.; Verhulst, S.L.; Claes, R.; Germonpré, P.R.; de Backer, W.A.
Title Functional imaging using computer methods to compare the effect of salbutamol and ipratropium bromide in patient-specific airway models of COPD Type A1 Journal article
Year 2011 Publication International journal of chronic obstructive pulmonary disease Abbreviated Journal Int J Chronic Obstr
Volume 6 Issue Pages 637-646
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract Background: Salbutamol and ipratropium bromide improve lung function in patients with chronic obstructive pulmonary disease (COPD). However, their bronchodilating effect has not yet been compared in the central and distal airways. Functional imaging using computational fluid dynamics offers the possibility of making such a comparison. The objective of this study was to assess the effects of salbutamol and ipratropium bromide on the geometry and computational fluid dynamics-based resistance of the central and distal airways.Methods: Five patients with Global Initiative for Chronic Obstructive Lung Disease Stage III COPD were randomized to a single dose of salbutamol or ipratropium bromide in a crossover manner with a 1-week interval between treatments. Patients underwent lung function testing and a multislice computed tomography scan of the thorax that was used for functional imaging. Two hours after dosing, the patients again underwent lung function tests and repeat computed tomography.Results: Lung function parameters, including forced expiratory volume in 1 second, vital capacity, overall airway resistance, and specific airway resistance, changed significantly after administration of each product. On functional imaging, the bronchodilating effect was greater in the distal airways, with a corresponding drop in airway resistance, compared with the central airways. Salbutamol and ipratropium bromide were equally effective at first glance when looking at lung function tests, but when viewed in more detail with functional imaging, hyporesponsiveness could be shown for salbutamol in one patient. Salbutamol was more effective in the other patients.Conclusion: This pilot study gives an innovative insight into the modes of action of salbutamol and ipratropium bromide in patients with COPD, using the new techniques of functional imaging and computational fluid dynamics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000208709800068 Publication Date 2011-11-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1178-2005; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.157 Times cited 25 Open Access
Notes ; ; Approved Most recent IF: 3.157; 2011 IF: NA
Call Number UA @ lucian @ c:irua:93165 Serial 1300
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Author Pham, A.-T.; Zhao, Q.-T.; Jungemann, C.; Meinerzhagen, B.; Mantl, S.; Sorée, B.; Pourtois, G.
Title Comparison of strained SiGe heterostructure-on-insulator (0 0 1) and (1 1 0) PMOSFETs : CV characteristics, mobility, and ON current Type A1 Journal article
Year 2011 Publication Solid state electronics Abbreviated Journal Solid State Electron
Volume 65-66 Issue Pages 64-71
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Strained SiGe heterostructure-on-insulator (0 0 1) and (1 1 0) PMOSFETs are investigated including important aspects like CV characteristics, mobility, and ON current. The simulations are based on the self-consistent solution of 6 × 6 k · p Schrödinger Equation, multi subband Boltzmann Transport Equation and Poisson Equation, and capture size quantization, strain, crystallographic orientation, and SiGe alloy effects on a solid physical basis. The simulation results are validated by comparison with different experimental data sources. The simulation results show that the strained SiGe HOI PMOSFET with (1 1 0) surface orientation has a higher gate capacitance and a much higher mobility and ON current compared to a similar device with the traditional (0 0 1) surface orientation.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000297182700012 Publication Date 2011-07-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1101; ISBN 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; 2011 IF: 1.397
Call Number UA @ lucian @ c:irua:92866 Serial 433
Permanent link to this record
 
 
Author De Backer, L.; Vos, W.; Dieriks, B.; Daems, D.; Verhulst, S.; Vinchurkar, S.; Ides, K.; de Backer, J.; Germonpré, P.; de Backer, W.
Title The effects of long-term noninvasive ventilation in hypercapnic COPD patients : a randomized controlled pilot study Type A1 Journal article
Year 2011 Publication International journal of chronic obstructive pulmonary disease Abbreviated Journal Int J Chronic Obstr
Volume 6 Issue Pages 615-624
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract Introduction: Noninvasive ventilation (NIV) is a well-established treatment for acute-on-chronic respiratory failure in hypercapnic COPD patients. Less is known about the effects of a long-term treatment with NIV in hypercapnic COPD patients and about the factors that may predict response in terms of improved oxygenation and lowered CO2 retention.Methods: In this study, we randomized 15 patients to a routine pharmacological treatment (n = 5, age 66 [standard deviation ± 6] years, FEV1 30.5 [±5.1] %pred, PaO2 65 [±6] mmHg, PaCO2 52.4 [±6.0] mmHg) or to a routine treatment and NIV (using the Synchrony BiPAP device [Respironics, Inc, Murrsville, PA]) (n = 10, age 65 [±7] years, FEV1 29.5 [±9.0] %pred, PaO2 59 [±13] mmHg, PaCO2 55.4 [±7.7] mmHg) for 6 months. We looked at arterial blood gasses, lung function parameters and performed a low-dose computed tomography of the thorax, which was later used for segmentation (providing lobe and airway volumes, iVlobe and iVaw) and post-processing with computer methods (providing airway resistance, iRaw) giving overall a functional image of the separate airways and lobes.Results: In both groups there was a nonsignificant change in FEV1 (NIV group 29.5 [9.0] to 38.5 [14.6] %pred, control group 30.5 [5.1] to 36.8 [8.7] mmHg). PaCO2 dropped significantly only in the NIV group (NIV: 55.4 [7.7] → 44.5 [4.70], P = 0.0076; control: 52.4 [6.0] → 47.6 [8.2], NS). Patients actively treated with NIV developed a more inhomogeneous redistribution of mass flow than control patients. Subsequent analysis indicated that in NIV-treated patients that improve their blood gases, mass flow was also redistributed towards areas with higher vessel density and less emphysema, indicating that flow was redistributed towards areas with better perfusion. There was a highly significant correlation between the % increase in mass flow towards lobes with a blood vessel density of >9% and the increase in PaO2. Improved ventilation–perfusion match and recruitment of previously occluded small airways can explain the improvement in blood gases.Conclusion: We can conclude that in hypercapnic COPD patients treated with long-term NIV over 6 months, a mass flow redistribution occurs, providing a better ventilation–perfusion match and hence better blood gases and lung function. Control patients improve homogeneously in iVaw and iRaw, without improvement in gas exchange since there is no improved ventilation/perfusion ratio or increased alveolar ventilation. These differences in response can be detected through functional imaging, which gives a more detailed report on regional lung volumes and resistances than classical lung function tests do. Possibly only patients with localized small airway disease are good candidates for long-term NIV treatment. To confirm this and to see if better arterial blood gases also lead to better health related quality of life and longer survival, we have to study a larger population.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000208709800066 Publication Date 2011-11-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1178-2005; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.157 Times cited 28 Open Access
Notes ; ; Approved Most recent IF: 3.157; 2011 IF: NA
Call Number UA @ lucian @ c:irua:93164 Serial 866
Permanent link to this record
 
 
Author Dzhurakhalov, A.A.; Peeters, F.M.
Title Structure and energetics of hydrogen chemisorbed on a single graphene layer to produce graphane Type A1 Journal article
Year 2011 Publication Carbon Abbreviated Journal Carbon
Volume 49 Issue 10 Pages 3258-3266
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Integrated Molecular Plant Physiology Research (IMPRES)
Abstract Chemisorption of hydrogen on graphene is studied using atomistic simulations with the second generation of reactive empirical bond order Brenner inter-atomic potential. The lowest energy adsorption sites and the most important metastable sites are determined. The H concentration is varied from a single H atom, to clusters of H atoms up to full coverage. We found that when two or more H atoms are present, the most stable configurations of H chemisorption on a single graphene layer are ortho hydrogen pairs adsorbed on one side or on both sides of the graphene sheet. The latter has the highest hydrogen binding energy. The next stable configuration is the orthopara pair combination, and then para hydrogen pairs. The structural changes of graphene caused by chemisorbed hydrogen are discussed and are compared with existing experimental data and other theoretical calculations. The obtained results will be useful for nanoengineering of graphene by hydrogenation and for hydrogen storage.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000291959300014 Publication Date 2011-04-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 46 Open Access
Notes ; A.D. thanks M.W. Zhao for a useful correspondence. This work was supported by the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-VI). ; Approved Most recent IF: 6.337; 2011 IF: 5.378
Call Number UA @ lucian @ c:irua:90877 Serial 3275
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Author Karapetrov, G.; Belkin, A.; Iavarone, M.; Fedor, J.; Novosad, V.; Milošević, M.V.; Peeters, F.M.
Title Anisotropic superconductivity and vortex dynamics in magnetically coupled F/S and F/S/F hybrids Type A1 Journal article
Year 2011 Publication Journal of superconductivity and novel magnetism Abbreviated Journal J Supercond Nov Magn
Volume 24 Issue 1/2 Pages 905-910
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Magnetically coupled superconductorferromagnet hybrids offer advanced routes for nanoscale control of superconductivity. Magnetotransport characteristics and scanning tunneling microscopy images of vortex structures in superconductorferromagnet hybrids reveal rich superconducting phase diagrams. Focusing on a particular combination of a ferromagnet with a well-ordered periodic magnetic domain structure with alternating out-of-plane component of magnetization, and a small coherence length superconductor, we find directed nucleation of superconductivity above the domain wall boundaries. We show that near the superconductor-normal state phase boundary the superconductivity is localized in narrow mesoscopic channels. In order to explore the Abrikosov flux line ordering in F/S hybrids, we use a combination of scanning tunneling microscopy and GinzburgLandau simulations. The magnetic stripe domain structure induces periodic local magnetic induction in the superconductor, creating a series of pinninganti-pinning channels for externally added magnetic flux quanta. Such laterally confined Abrikosov vortices form quasi-1D arrays (chains). The transitions between multichain states occur through propagation of kinks at the intermediate fields. At high fields we show that the system becomes nonlinear due to a change in both the number of vortices and the confining potential. In F/S/F hybrids we demonstrate the evolution of the anisotropic conductivity in the superconductor that is magnetically coupled with two adjacent ferromagnetic layers. Stripe magnetic domain structures in both F-layers are aligned under each other, resulting in a directional superconducting order parameter in the superconducting layer. The conductance anisotropy strongly depends on the period of the magnetic domains and the strength of the local magnetization. The anisotropic conductivity of up to three orders of magnitude can be achieved with a spatial critical temperature modulation of 5% of T c. Induced anisotropic properties in the F/S and F/S/F hybrids have a potential for future application in switching and nonvolatile memory elements operating at low temperatures.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000289855700150 Publication Date 2010-10-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1557-1939;1557-1947; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.18 Times cited 2 Open Access
Notes ; This work as well as the use of the Center for Nanoscale Materials and the Electron Microscopy Center at Argonne National Laboratory were supported by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. This work was also supported by the Ministry of Education, Agency for Structural Funds of the European Union, Research and Development Program, under agreement 262 401 200 19. M.V.M. and F. M. P. acknowledge support from the Flemish Science Foundation (FWO-VI), the Belgian Science Policy, the JSPS/ESF-NES program, the ESF-AQDJJ network, and the Vlaanderen-USA bilateral program. ; Approved Most recent IF: 1.18; 2011 IF: 0.650
Call Number UA @ lucian @ c:irua:89930 Serial 130
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Author Matulis, A.; Masir, M.R.; Peeters, F.M.
Title Application of optical beams to electrons in graphene Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 11 Pages 115458-115458,7
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288896400013 Publication Date 2011-03-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 13 Open Access
Notes ; This research was supported by the Flemish Science Foundation (Grant No. FWO-Vl), by the Belgian Science policy (IAP), and (in part) by the Lithuanian Science Council under project No. MIP-79/2010. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:89377 Serial 142
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Author Apolinario, S.W.S.; Peeters, F.M.
Title Binary dusty plasma Coulomb balls Type A1 Journal article
Year 2011 Publication Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics Abbreviated Journal Phys Rev E
Volume 83 Issue 4 Pages 041136,1-041136,8
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigated the mixing and segregation of a system consisting of two different species of particles, having different charges, interacting through a pure Coulomb potential, and confined in a three-dimensional parabolic trap. The structure of the cluster and its normal mode spectrum are analyzed as a function of the relative charge and the relative number of different types of particles. We found that (a) the system can be in a mixed or segregated state depending on the relative charge ratio parameter and (b) the segregation process is mediated by a first or second order structural phase transition which strongly influences the magic cluster properties of the system.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000290154900004 Publication Date 2011-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1539-3755;1550-2376; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.366 Times cited 10 Open Access
Notes ; This work was supported by FACEPE (Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco) and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 2.366; 2011 IF: 2.255
Call Number UA @ lucian @ c:irua:89716 Serial 236
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Author Neek-Amal, M.; Peeters, F.M.
Title Buckled circular monolayer graphene : a graphene nano-bowl Type A1 Journal article
Year 2011 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 23 Issue 4 Pages 045002-045002,8
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the stability of circular monolayer graphene subjected to a radial load using non-equilibrium molecular dynamics simulations. When monolayer graphene is radially stressed, after some small circular strain (~0.4%) it buckles and bends into a new bowl-like shape. Young's modulus is calculated from the linear relation between stress and strain before the buckling threshold, which is in agreement with experimental results. The prediction of elasticity theory for the buckling threshold of a radially stressed plate is presented and its results are compared to the one of our atomistic simulation. The Jarzynski equality is used to estimate the difference between the free energy of the non-compressed states and the buckled states. From a calculation of the free energy we obtain the optimum radius for which the system feels the minimum boundary stress.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000286142800003 Publication Date 2010-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 27 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; Approved Most recent IF: 2.649; 2011 IF: 2.546
Call Number UA @ lucian @ c:irua:88043 Serial 259
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Author Zarenia, M.; Pereira, J.M.; Farias, G.A.; Peeters, F.M.
Title Chiral states in bilayer graphene : magnetic field dependence and gap opening Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 12 Pages 125451-125451,13
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract At the interface of electrostatic potential kink profiles, one-dimensional chiral states are found in bilayer graphene (BLG). Such structures can be created by applying an asymmetric potential to the upper and the lower layers of BLG. We found the following: (i) due to the strong confinement by the single kink profile, the unidirectional states are only weakly affected by a magnetic field; (ii) increasing the smoothness of the kink potential results in additional bound states, which are topologically different from those chiral states; and (iii) in the presence of a kink-antikink potential, the overlap between the oppositely moving chiral states results in the appearance of crossing and anticrossing points in the energy spectrum. This leads to the opening of tunable minigaps in the spectrum of the unidirectional topological states.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000295484300016 Publication Date 2011-09-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 50 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-VI), the Belgian Science Policy (IAP), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CONGRAN), the Brazilian agency CNPq (Pronex), and the bilateral projects between Flanders and Brazil and the collaboration project FWO-CNPq. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:92915 Serial 358
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Author Chaves, A.; Komendová, L.; Milošević, M.V.; Andrade, J.S.; Farias, G.A.; Peeters, F.M.
Title Conditions for nonmonotonic vortex interaction in two-band superconductors Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 21 Pages 214523-214523,6
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We describe a semianalytic approach to the two-band Ginzburg-Landau theory, which predicts the behavior of vortices in two-band superconductors. We show that the character of the short-range vortex-vortex interaction is determined by the sign of the normal domain-superconductor interface energy, in analogy with the conventional differentiation between type I and type II superconductors. However, we also show that the long-range interaction is determined by a modified Ginzburg-Landau parameter κ*, different from the standard κ of a bulk superconductor. This opens the possibility for nonmonotonic vortex-vortex interaction, which is temperature dependent, and can be further tuned by alterations of the material on the microscopic scale.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000292252300009 Publication Date 2011-06-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 46 Open Access
Notes ; Discussions with A. Moreira, A. Shanenko, R. Prozorov, and A. Golubov are gratefully acknowledged. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral project FWO-CNPq, CAPES, and PRONEX/CNPq/FUNCAP. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:90922 Serial 477
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Author Peelaers, H.; Partoens, B.; Giantomassi, M.; Rangel, T.; Goossens, E.; Rignanese, G.-M.; Gonze, X.; Peeters, F.M.
Title Convergence of quasiparticle band structures of Si and Ge nanowires in the GW approximation and the validity of scissor shifts Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 4 Pages 045306-045306,6
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Starting from fully converged density-functional theory calculations, the quasiparticle corrections are calculated for different sized Si and Ge nanowires using the GW approximation. The effectiveness of recently developed techniques in speeding up the convergence of the quasiparticle calculations is demonstrated. The complete quasiparticle band structures are also obtained using an interpolation technique based on maximallylocalized Wannier functions. From the quasiparticle results, we assess the correctness of the commonly applied scissor-shift correction. Dispersion changes are observed, which are also reflected in changes in the effective band masses calculated taking into account quasiparticle corrections.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000286771400004 Publication Date 2011-01-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 18 Open Access
Notes ; We are grateful to Yann Pouillon for valuable technical support with the build system of ABINIT, related to the WANNIER90 library. This work was supported by the Flemish Science Foundation (FWO-Vl) and by the Interuniversity Attraction Poles Program (P6/42)-Belgian State-Belgian Science Policy. X. G. and G.-M. R. acknowledge funding from the EU's 7th Framework Programme through the ETSF I3 e-Infrastructure project (Grant No. 211956), the Communaute francaise de Belgique through the Action de Recherche Concertee 07/12-003 “Nanosystemes hybrides metal-organiques,” and the Wallon Region Project No. 816849 “ European Theoretical Spectroscopy Facility” (WALL ETSF). M. G. acknowledges funding from the FRFC Project No. 2.4.589.09.F. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:86905 Serial 510
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Author Komendová, L.; Milošević, M.V.; Shanenko, A.A.; Peeters, F.M.
Title Different length scales for order parameters in two-gap superconductors : extended Ginzburg-Landau theory Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 6 Pages 064522-064522,5
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the Ginzburg-Landau theory extended to the next-to-leading order, we determine numerically the healing lengths of the two order parameters at the two-gap superconductor/normal metal interface. We demonstrate on several examples that those can be different even in the strict domain of applicability of the Ginzburg-Landau theory. This justifies the use of this theory to describe relevant physics of two-gap superconductors, distinguishing them from their single-gap counterparts. The calculational degree of complexity increases only slightly with respect to the conventional Ginzburg-Landau expansion, thus the extended Ginzburg-Landau model remains numerically far less demanding compared to the full microscopic approaches.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000294226000013 Publication Date 2011-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 56 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF-INSTANS network. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:92414 Serial 695
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Author Tkachenko, D.V.; Sheridan, T.E.; Misko, V.R.
Title Dispersion relations for circular single and double dusty plasma chains Type A1 Journal article
Year 2011 Publication Physics of plasmas Abbreviated Journal Phys Plasmas
Volume 18 Issue 10 Pages 103709,1-103709,10
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We derive dispersion relations for a system of identical particles confined in a two-dimensional annular harmonic well and which interact through a Yukawa potential, e.g., a dusty plasma ring. When the particles are in a single chain (i.e., a one-dimensional ring), we find a longitudinal acoustic mode and a transverse optical mode which show approximate agreement with the dispersion relation for a straight configuration for large radii of the ring. When the radius decreases, the dispersion relations modify: there appears an anticrossing of the modes near the crossing point resulting in a frequency gap between the lower and upper branches of the modified dispersion relations. For the double chain (i.e., a two-dimensional zigzag configuration), the dispersion relation has four branches: longitudinal acoustic and optical and transverse acoustic and optical.
Address
Corporate Author Thesis
Publisher Place of Publication Woodbury, N.Y. Editor
Language Wos 000296529600090 Publication Date 2011-10-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.115 Times cited 7 Open Access
Notes ; We acknowledge fruitful discussions with F.M. Peeters, A. Matulis, and W.P. Ferreira. This work was supported by the “Odysseus” program of the Flemish Government and FWO-Vl. ; Approved Most recent IF: 2.115; 2011 IF: 2.147
Call Number UA @ lucian @ c:irua:94052 Serial 738
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Author Khaydarov, R.T.; Beisinbaeva, H.B.; Sabitov, M.M.; Kalal, M.; Berdiyorov, G.R.
Title Effect of light gas atom inclusions on the characteristics of laser-produced plasma ions Type A1 Journal article
Year 2011 Publication Nuclear fusion Abbreviated Journal Nucl Fusion
Volume 51 Issue 10 Pages 103041,1-103041,3
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the mass-spectrometric method we studied the effect of light gas inclusions on the formation process of multi-component laser-induced plasma ions. Masscharge characteristics, as well as energy and spatial distribution of the plasma ions are analysed. We found that both the energy and maximal charge of heavy component ions decrease due to the presence of gas atoms in the solid target surface layer.
Address
Corporate Author Thesis
Publisher Place of Publication Vienna Editor
Language Wos 000296603800043 Publication Date 2011-09-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0029-5515;1741-4326; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.307 Times cited 1 Open Access
Notes ; ; Approved Most recent IF: 3.307; 2011 IF: 4.090
Call Number UA @ lucian @ c:irua:93761 Serial 821
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Author Sofo, J.O.; Suarez, A.M.; Usaj, G.; Cornaglia, P.S.; Hernández-Nieves, A.D.; Balseiro, C.A.
Title Electrical control of the chemical bonding of fluorine on graphene Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 8 Pages 081411
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the electronic structure of diluted F atoms chemisorbed on graphene using density functional theory calculations. We show that the nature of the chemical bonding of a F atom adsorbed on top of a C atom in graphene strongly depends on carrier doping. In neutral samples the F impurities induce a sp(3)-like bonding of the C atom below, generating a local distortion of the hexagonal lattice. As the graphene is electron-doped, the C atom retracts back to the graphene plane and for high doping (10(14) cm(-2)) its electronic structure corresponds to a nearly pure sp(2) configuration. We interpret this sp(3)-sp(2) doping-induced crossover in terms of a simple tight-binding model and discuss the physical consequences of this change.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000287484800005 Publication Date 2011-02-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 65 Open Access
Notes ; J.O.S. and A. S. acknowledge support from the Donors of the American Chemical Society Petroleum Research Fund and use of facilities at the Penn State Materials Simulation Center. G. U., P. S. C., A. D. H., and C. A. B. acknowledge financial support from PICTs 06-483 and 2008-2236 from ANPCyT and PIP 11220080101821 from CONICET, Argentina. A. D. H. acknowledges support from the Flemish Science Foundation (FWO). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:105600 Serial 892
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Author Grujić, M.; Zarenia, M.; Chaves, A.; Tadić, M.; Farias, G.A.; Peeters, F.M.
Title Electronic and optical properties of a circular graphene quantum dot in a magnetic field : influence of the boundary conditions Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 20 Pages 205441-205441,12
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract An analytical approach, using the Dirac-Weyl equation, is implemented to obtain the energy spectrum and optical absorption of a circular graphene quantum dot in the presence of an external magnetic field. Results are obtained for the infinite-massand zigzag boundary conditions. We found that the energy spectrum of a dot with the zigzag boundary condition exhibits a zero-energy band regardless of the value of the magnetic field, while for the infinite-mass boundary condition, the zero-energy states appear only for high magnetic fields. The analytical results are compared to those obtained from the tight-binding model: (i) we show the validity range of the continuum model and (ii) we find that the continuum model with the infinite-mass boundary condition describes rather well its tight-binding analog, which can be partially attributed to the blurring of the mixed edges by the staggered potential.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297295400011 Publication Date 2011-11-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 78 Open Access
Notes ; This work was supported by the EuroGraphene programme of the ESF (project CONGRAN), the Ministry of Education and Science of Serbia, the Belgian Science Policy (IAP), the bilateral projects between Flanders and Brazil, the Flemish Science Foundation (FWO-Vl), and the Brazilian Research Council (CNPq). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:94025 Serial 997
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Author Zarenia, M.; Chaves, A.; Farias, G.A.; Peeters, F.M.
Title Energy levels of triangular and hexagonal graphene quantum dots : a comparative study between the tight-binding and Dirac equation approach Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 24 Pages 245403-245403,12
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The Dirac equation is solved for triangular and hexagonal graphene quantum dots for different boundary conditions in the presence of a perpendicular magnetic field. We analyze the influence of the dot size and its geometry on their energy spectrum. A comparison between the results obtained for graphene dots with zigzag and armchair edges, as well as for infinite-mass boundary condition, is presented and our results show that the type of graphene dot edge and the choice of the appropriate boundary conditions have a very important influence on the energy spectrum. The single-particle energy levels are calculated as a function of an external perpendicular magnetic field that lifts degeneracies. Comparing the energy spectra obtained from the tight-binding approximation to those obtained from the continuum Dirac equation approach, we verify that the behavior of the energies as a function of the dot size or the applied magnetic field are qualitatively similar, but in some cases quantitative differences can exist.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297767800008 Publication Date 2011-12-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 145 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE (project CONGRAN), the Bilateral program between Flanders and Brazil, CAPES and the Brazilian Council for Research (CNPq). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:93961 Serial 1040
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Author Saniz, R.; Barbiellini, B.; Denison, A.B.; Bansil, A.
Title Erratum: Spontaneous magnetization and electron momentum density in three-dimensional quantum dots [Phys. Rev. B 68, 165326 (2003)] Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 11 Pages 119907
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000295263600015 Publication Date 2011-09-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record
Impact Factor 3.836 Times cited Open Access
Notes ; ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:92919 Serial 1081
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Author Tadić, M.; Čukarić, N.; Arsoski, V.; Peeters, F.M.
Title Excitonic Aharonov-Bohm effect : unstrained versus strained type-I semiconductor nanorings Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 12 Pages 125307-125307,13
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study how mechanical strain affects the magnetic field dependence of the exciton states in type-I semiconductor nanorings. Strain spatially separates the electron and hole in (In,Ga)As/GaAs nanorings which is beneficial for the occurrence of the excitonic Aharonov-Bohm (AB) effect. In narrow strained (In,Ga)As/GaAs nanorings the AB oscillations in the exciton ground-state energy are due to anticrossings with the first excited state. No such AB oscillations are found in unstrained GaAs/(Al,Ga)As nanorings irrespective of the ring width. Our results are obtained within an exact numerical diagonalization scheme and are shown to be accurately described by a two-level model with off-diagonal coupling t. The later transfer integral expresses the Coulomb coupling between states of electron-hole pairs. We also found that the oscillator strength for exciton recombination in (In,Ga)As/GaAs nanorings exhibits AB oscillations, which are superimposed on a linear increase with magnetic field. Our results agree qualitatively with recent experiments on the excitonic Aharonov-Bohm effect in type-I (In,Ga)As/GaAs nanorings.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000294777400013 Publication Date 2011-09-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 13 Open Access
Notes ; This work was supported by the Ministry of Education and Science of Serbia, the Flemish Science Foundation (FWO-Vl), the EU NoE: SANDiE, and the Belgian Science Policy (IAP). The calculations were performed on the CalcUA and Seastar computer clusters of the University of Antwerp. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:92326 Serial 1122
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