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Author Masir, M.R.; Moldovan, D.; Peeters, F.M. pdf  doi
openurl 
  Title Pseudo magnetic field in strained graphene : revisited Type A1 Journal article
  Year 2013 Publication Solid state communications Abbreviated Journal Solid State Commun  
  Volume 175 Issue Pages 76-82  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We revisit the theory of the pseudo magnetic field as induced by strain in graphene using the tight- binding approach. A systematic expansion of the hopping parameter and the deformation of the lattice vectors is presented from which we obtain an expression for the pseudo magnetic field for low energy electrons. We generalize and discuss previous results and propose a novel effective Hamiltonian. The contributions of the different terms to the pseudo field expression are investigated for a model triaxial strain profile and are compared with the full solution. Our work suggests that the previous proposed pseudo magnetic field expression is valid up to reasonably high strain (15%) and there is no K-dependent pseudo-magnetic field.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000329538200010 Publication Date 2013-04-06  
  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 57 Open Access  
  Notes (up) This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EURO- CORES Program EuroGRAPHENE within the project CONGRAN and the Methusalem programme of the Flemish government. Approved Most recent IF: 1.554; 2013 IF: 1.698  
  Call Number UA @ lucian @ c:irua:114805 Serial 2737  
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Author Milovanović, S.P.; Masir, M.R.; Peeters, F.M. pdf  doi
openurl 
  Title Spectroscopy of snake states using a graphene Hall bar Type A1 Journal article
  Year 2013 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 103 Issue 23 Pages 233502-233504  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract An approach to observe snake states in a graphene Hall bar containing a pn-junction is proposed. The magnetic field dependence of the bend resistance in a ballistic graphene Hall bar structure containing a tilted pn-junction oscillates as a function of applied magnetic field. We show that each oscillation is due to a specific snake state that moves along the pn-interface. Furthermore, depending on the value of the magnetic field and applied potential, we can control the lead in which the electrons will end up and hence control the response of the system.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000328634900090 Publication Date 2013-12-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.411 Times cited 15 Open Access  
  Notes (up) This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN and the Methusalem Foundation of the Flemish government. Approved Most recent IF: 3.411; 2013 IF: 3.515  
  Call Number UA @ lucian @ c:irua:113710 Serial 3074  
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Author Milovanovic, S.P.; Masir, M.R.; Peeters, F.M. pdf  doi
openurl 
  Title Bilayer graphene Hall bar with a pn-junction Type A1 Journal article
  Year 2013 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 114 Issue 11 Pages 113706  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We investigate the magnetic field dependence of the Hall and the bend resistances for a ballistic Hall bar structure containing a pn-junction sculptured from a bilayer of graphene. The electric response is obtained using the billiard model, and we investigate the cases of bilayer graphene with and without a band gap. Two different conduction regimes are possible: (i) both sides of the junction have the same carrier type and (ii) one side of the junction is n-type while the other one is p-type. The first case shows Hall plateau-like features in the Hall resistance that fade away as the band gap opens. The second case exhibits a bend resistance that is asymmetric in magnetic field as a consequence of snake states along the pn-interface, where the maximum is shifted away from zero magnetic field.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000324827200031 Publication Date 2013-09-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 3 Open Access  
  Notes (up) This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. Approved Most recent IF: 2.068; 2013 IF: 2.185  
  Call Number UA @ lucian @ c:irua:111169 Serial 234  
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Author Milovanovic, S.P.; Masir, M.R.; Peeters, F.M. pdf  doi
openurl 
  Title Graphene hall bar with an asymmetric pn-junction Type A1 Journal article
  Year 2013 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 113 Issue 19 Pages 193701-193708  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We investigated the magnetic field dependence of the Hall and the bend resistances in the ballistic regime for a single layer graphene Hall bar structure containing a pn-junction. When both regions are n-type the Hall resistance dominates and Hall type of plateaus are formed. These plateaus occur as a consequence of the restriction on the angle imposed by Snell's law allowing only electrons with a certain initial angles to transmit though the potential step. The size of the plateau and its position is determined by the position of the potential interface as well as the value of the applied potential. When the second region is p-type, the bend resistance dominates, which is asymmetric in field due to the presence of snake states. Changing the position of the pn-interface in the Hall bar strongly affects these states and therefore the bend resistance is also changed. Changing the applied potential, we observe that the bend resistance exhibits a peak around the charge-neutrality point (CNP), which is independent of the position of the pn-interface, while the Hall resistance shows a sign reversal when the CNP is crossed, which is in very good agreement with a recent experiment [J. R. Williams and C. M. Marcus, Phys. Rev. Lett. 107, 046602 (2011)].  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000319295200022 Publication Date 2013-05-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 7 Open Access  
  Notes (up) This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. We acknowledge fruitful discussions with M. Barbier. Approved Most recent IF: 2.068; 2013 IF: 2.185  
  Call Number UA @ lucian @ c:irua:108999 Serial 1371  
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Author Borgatti, F.; Park, C.; Herpers, A.; Offi, F.; Egoavil, R.; Yamashita, Y.; Yang, A.; Kobata, M.; Kobayashi, K.; Verbeeck, J.; Panaccione, G.; Dittmann, R.; pdf  doi
openurl 
  Title Chemical insight into electroforming of resistive switching manganite heterostructures Type A1 Journal article
  Year 2013 Publication Nanoscale Abbreviated Journal Nanoscale  
  Volume 5 Issue 9 Pages 3954-3960  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract We have investigated the role of the electroforming process in the establishment of resistive switching behaviour for Pt/Ti/Pr0.5Ca0.5MnO3/SrRuO3 layered heterostructures (Pt/Ti/PCMO/SRO) acting as non-volatile Resistance Random Access Memories (RRAMs). Electron spectroscopy measurements demonstrate that the higher resistance state resulting from electroforming of as-prepared devices is strictly correlated with the oxidation of the top electrode Ti layer through field-induced electromigration of oxygen ions. Conversely, PCMO exhibits oxygen depletion and downward change of the chemical potential for both resistive states. Impedance spectroscopy analysis, supported by the detailed knowledge of these effects, provides an accurate model description of the device resistive behaviour. The main contributions to the change of resistance from the as-prepared (low resistance) to the electroformed (high resistance) states are respectively due to reduced PCMO at the boundary with the Ti electrode and to the formation of an anisotropic np junction between the Ti and the PCMO layers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000317859400051 Publication Date 2013-03-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364;2040-3372; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.367 Times cited 40 Open Access  
  Notes (up) Vortex; Countatoms ECASJO_; Approved Most recent IF: 7.367; 2013 IF: 6.739  
  Call Number UA @ lucian @ c:irua:108710UA @ admin @ c:irua:108710 Serial 348  
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Author Maignan, A.; Singh, K.; Simon, C.; Lebedev, O.I.; Martin, C.; Tan, H.; Verbeeck, J.; Van Tendeloo, G. pdf  doi
openurl 
  Title Magnetic and magnetodielectric properties of erbium iron garnet ceramic Type A1 Journal article
  Year 2013 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 113 Issue 3 Pages 033905-5  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract An Er3Fe5O12 ceramic has been sintered in oxygen atmosphere at 1400 °C for dielectric measurements. Its structural quality at room temperature has been checked by combining transmission electron microscopy and X-ray diffraction. It crystallizes in the cubic space group Ia3d with a = 12.3488(1). The dielectric permittivity ([variantgreekepsilon]′) and losses (tan δ) measurements as a function of temperature reveal the existence of two anomalies, a broad one between 110 K and 80 K, attributed to the Er3+ spin reorientation, and a second sharper feature at about 45 K associated to the appearance of irreversibility on the magnetic susceptibility curves. In contrast to the lack of magnetic field impact on [variantgreekepsilon]′ for the former anomaly, a complex magnetic field effect has been evidenced below 45 K. The isothermal [variantgreekepsilon]′(H) curves show the existence of positive magnetodielectric effect, reaching a maximum of 0.14% at 3 T and 10 K. Its magnitude decreases as H is further increased. Interestingly, for the lowest H values, a linear regime in the [variantgreekepsilon]′(H) curve is observed. From this experimental study, it is concluded that the [variantgreekepsilon]′ anomaly, starting above the compensation temperature Tc (75 K) and driven by the internal magnetic field, is not sensitive to an applied external magnetic field. Thus, below 45 K, it is the magnetic structure which is responsible for the coupling between spin and charge in this iron garnet.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000313670600042 Publication Date 2013-01-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 15 Open Access  
  Notes (up) Vortex; Countatoms ECASJO_; Approved Most recent IF: 2.068; 2013 IF: 2.185  
  Call Number UA @ lucian @ c:irua:106182UA @ admin @ c:irua:106182 Serial 1861  
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Author Guzzinati, G.; Schattschneider, P.; Bliokh, K.Y.; Nori, F.; Verbeeck, J. url  doi
openurl 
  Title Observation of the Larmor and Gouy rotations with electron vortex beams Type A1 Journal article
  Year 2013 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 110 Issue 9 Pages 093601  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Electron vortex beams carrying intrinsic orbital angular momentum (OAM) are produced in electron microscopes where they are controlled and focused by using magnetic lenses. We observe various rotational phenomena arising from the interaction between the OAM and magnetic lenses. First, the Zeeman coupling, proportional to the OAM and magnetic field strength, produces an OAM-independent Larmor rotation of a mode superposition inside the lens. Second, when passing through the focal plane, the electron beam acquires an additional Gouy phase dependent on the absolute value of the OAM. This brings about the Gouy rotation of the superposition image proportional to the sign of the OAM. A combination of the Larmor and Gouy effects can result in the addition (or subtraction) of rotations, depending on the OAM sign. This behavior is unique to electron vortex beams and has no optical counterpart, as Larmor rotation occurs only for charged particles. Our experimental results are in agreement with recent theoretical predictions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000315380800005 Publication Date 2013-02-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 91 Open Access  
  Notes (up) Vortex; Countatoms ECASJO_; Approved Most recent IF: 8.462; 2013 IF: 7.728  
  Call Number UA @ lucian @ c:irua:106181UA @ admin @ c:irua:106181 Serial 2422  
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Author Molina, L.; Egoavil, R.; Turner, S.; Thersleff, T.; Verbeeck, J.; Holzapfel, B.; Eibl, O.; Van Tendeloo, G. pdf  doi
openurl 
  Title Interlayer structure in YBCO-coated conductors prepared by chemical solution deposition Type A1 Journal article
  Year 2013 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech  
  Volume 26 Issue 7 Pages 075016-75018  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The functionality of YBa2Cu3O7−δ (YBCO)-coated conductor technology depends on the reliability and microstructural properties of a given tape or wire architecture. Particularly, the interface to the metal tape is of interest since it determines the adhesion, mechanical stability of the film and thermal contact of the film to the substrate. A trifluoroacetate (TFA)metal organic deposition (MOD) prepared YBCO film deposited on a chemical solution-derived buffer layer architecture based on CeO2/La2Zr2O7 and grown on a flexible Ni5 at.%W substrate with a {100}⟨001⟩ biaxial texture was investigated. The YBCO film had a thickness was 440 nm and a jc of 1.02 MA cm−2 was determined at 77 K and zero external field. We present a sub-nanoscale analysis of a fully processed solution-derived YBCO-coated conductor by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS). For the first time, structural and chemical analysis of the valence has been carried out on the sub-nm scale. Intermixing of Ni, La, Ce, O and Ba takes place at these interfaces and gives rise to nanometer-sized interlayers which are a by-product of the sequential annealing process. Two distinct interfacial regions were analyzed in detail: (i) the YBCO/CeO2/La2Zr2O7 region (10 nm interlayer) and (ii) the La2Zr2O7/Ni5 at.%W substrate interface region (20 nm NiO). This is of particular significance for the functionality of these YBCO-coated conductor architectures grown by chemical solution deposition.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos 000319973800024 Publication Date 2013-05-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.878 Times cited 11 Open Access  
  Notes (up) vortex; Countatoms; Fwo; Esteem2; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 2.878; 2013 IF: 2.796  
  Call Number UA @ lucian @ c:irua:108704UA @ admin @ c:irua:108704 Serial 1698  
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Author da Pieve, F.; Hogan, C.; Lamoen, D.; Verbeeck, J.; Vanmeert, F.; Radepont, M.; Cotte, M.; Janssens, K.; Gonze, X.; Van Tendeloo, G. url  doi
openurl 
  Title Casting light on the darkening of colors in historical paintings Type A1 Journal article
  Year 2013 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 111 Issue 20 Pages 208302-208305  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The degradation of colors in historical paintings affects our cultural heritage in both museums and archeological sites. Despite intensive experimental studies, the origin of darkening of one of the most ancient pigments known to humankind, vermilion (α-HgS), remains unexplained. Here, by combining many-body theoretical spectroscopy and high-resolution microscopic x-ray diffraction, we clarify the composition of the damaged paint work and demonstrate possible physicochemical processes, induced by illumination and exposure to humidity and air, that cause photoactivation of the original pigment and the degradation of the secondary minerals. The results suggest a new path for the darkening process which was never considered by previous studies and prompt a critical examination of their findings.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000327244500003 Publication Date 2013-11-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 30 Open Access  
  Notes (up) Vortex; ERC FP7; COUNTATOMS; ECASJO_; Approved Most recent IF: 8.462; 2013 IF: 7.728  
  Call Number UA @ lucian @ c:irua:111396UA @ admin @ c:irua:111396 Serial 287  
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Author Clark, L.; Béché, A.; Guzzinati, G.; Lubk, A.; Mazilu, M.; Van Boxem, R.; Verbeeck, J. url  doi
openurl 
  Title Exploiting lens aberrations to create electron-vortex beams Type A1 Journal article
  Year 2013 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 111 Issue 6 Pages 064801-64805  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A model for a new electron-vortex beam production method is proposed and experimentally demonstrated. The technique calls on the controlled manipulation of the degrees of freedom of the lens aberrations to achieve a helical phase front. These degrees of freedom are accessible by using the corrector lenses of a transmission electron microscope. The vortex beam is produced through a particular alignment of these lenses into a specifically designed astigmatic state and applying an annular aperture in the condenser plane. Experimental results are found to be in good agreement with simulations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000322921200009 Publication Date 2013-08-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 66 Open Access  
  Notes (up) Vortex; Esteem2; Countatoms; FWO; Esteem2jra3 ECASJO; Approved Most recent IF: 8.462; 2013 IF: 7.728  
  Call Number UA @ lucian @ c:irua:109340UA @ admin @ c:irua:109340 Serial 1148  
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Author Van Hoorebeke, L.; Leroux, O.; Leroux, F.; Mastroberti, A.A.; Santos-Silva, F.; Van Loo, D.; Bagniewska-Zadworna, A.; Bals, S.; Popper, Z.A.; de Araujo Mariath, J.E. doi  openurl
  Title Heterogeneity of silica and glycan-epitope distribution in epidermal idioblast cell walls in Adiantum raddianum laminae Type A1 Journal article
  Year 2013 Publication Planta Abbreviated Journal Planta  
  Volume 237 Issue 6 Pages 1453-1464  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Laminae of Adiantum raddianum Presl., a fern belonging to the family Pteridaceae, are characterised by the presence of epidermal fibre-like cells under the vascular bundles. These cells were thought to contain silica bodies, but their thickened walls leave no space for intracellular silica suggesting it may actually be deposited within their walls. Using advanced electron microscopy in conjunction with energy dispersive X-ray microanalysis we showed the presence of silica in the cell walls of the fibre-like idioblasts. However, it was specifically localised to the outer layers of the periclinal wall facing the leaf surface, with the thick secondary wall being devoid of silica. Immunocytochemical experiments were performed to ascertain the respective localisation of silica deposition and glycan polymers. Epitopes characteristic for pectic homogalacturonan and the hemicelluloses xyloglucan and mannan were detected in most epidermal walls, including the silica-rich cell wall layers. The monoclonal antibody, LM6, raised against pectic arabinan, labelled the silica-rich primary wall of the epidermal fibre-like cells and the guard cell walls, which were also shown to contain silica. We hypothesise that the silicified outer wall layers of the epidermal fibre-like cells support the lamina during cell expansion prior to secondary wall formation. This implies that silicification does not impede cell elongation. Although our results suggest that pectic arabinan may be implicated in silica deposition, further detailed analyses are needed to confirm this. The combinatorial approach presented here, which allows correlative screening and in situ localisation of silicon and cell wall polysaccharide distribution, shows great potential for future studies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000319474200004 Publication Date 2013-02-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0032-0935;1432-2048; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.361 Times cited 16 Open Access  
  Notes (up) We are grateful to the Laboratorio de Anatomia Vegetal of Universidade Federal do Rio Grande do Sul (UFRGS) and the Centro de Microscopia Eletronica (CME) of UFRGS. Thanks to Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for the undergraduate degree grant provided (PIBIC) for the fourth author and research grant and support for the last one. The third author is grateful to Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) for providing financial support (PRODOC). We acknowledge Christiane de Queiroz Lopes and Moema Queiroz (CME) for the technical assistance. We are indebted to Paul Knox (Centre for Plant Sciences, University of Leeds, UK) for kindly providing the monoclonal antibodies used in this study. The Fund for Scientific Research-Flanders (FWO) is acknowledged for the doctoral grant to D. Van Loo (G.0100.08). Approved Most recent IF: 3.361; 2013 IF: 3.376  
  Call Number UA @ lucian @ c:irua:109641 Serial 1419  
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