| Records |
| Author |
Papp, G.; Peeters, F.M. |
| Title |
Magneto-ballistic transport through micro-structured junctions on a curved two-dimensional electron gas |
Type |
A1 Journal article |
Year  |
2009 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
| Volume |
149 |
Issue |
19/20 |
Pages |
778-780 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate theoretically the ballistic transport in a two-dimensional electron gas, which is rolled up as a tube and is micro-structured into a Hall bar. A uniform magnetic field applied to such a curved surface results in a non-uniform perpendicular magnetic field. The bend resistances become asymmetric with respect to the orientation of the magnetic field due to the varying magnetic field along the junction. The resistance asymmetry is strongly affected by corrugation due to the varying mobility along different crystallographic directions. We compare our results with a recent transport measurement. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000266149900011 |
Publication Date |
2009-03-07 |
| 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 |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.554; 2009 IF: 1.837 |
| Call Number |
UA @ lucian @ c:irua:77580 |
Serial |
1897 |
| Permanent link to this record |
| |
|
| |
| Author |
Krata, A.; Kontozova-Deutsch, V.; Bencs, L.; Deutsch, F.; Van Grieken, R. |
| Title |
Single-run ion chromatographic separation of inorganic and low-molecular-mass organic anions under isocratic elution: application to environmental samples |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Talanta : the international journal of pure and applied analytical chemistry |
Abbreviated Journal |
|
| Volume |
79 |
Issue |
1 |
Pages |
16-21 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
For the isocratic ion chromatography (IC) separation of low-molecular-mass organic acids and inorganic anions three different anion-exchange columns were studied: IonPac AS14 (9 ìm particle size), Allsep A-2 (7 ìm particle size), and IC SI-50 4E (5 ìm particle size). A complete baseline separation for all analyzed anions (i.e., F−, acetate, formate, Cl−, NO2−, Br−, NO3−, HPO42− and SO42−) in one analytical cycle of shorter than 17 min was achieved on the IC SI-50 4E column, using an eluent mixture of 3.2 mM Na2CO3 and 1.0 mM NaHCO3 with a flow rate of 1.0 mL min−1. On the IonPac AS14 column, it was possible to separate acetate from inorganic anions in one run (i.e., less than 9 min), but not formate, under the following conditions: 3.5 mM Na2CO3 plus 1.0 mM NaHCO3 with a flow rate of 1.2 mL min−1. Therefore, it was necessary to adapt a second run with a 2.0 mM Na2B4O7 solution as an eluent under a flow rate of 0.8 mL min−1 for the separation of organic ions, which considerably enlarged the analysis time. For the Allsep A-2 column, using an eluent mixture of 1.2 mM Na2CO3 plus 1.5 mM NaHCO3 with a flow rate of 1.6 mL min−1, it was possible to separate almost all anions in one run within 25 min, except the fluoride-acetate critical pair. A Certified Multianion Standard Solution PRIMUS for IC was used for the validation of the analytical methods. The lowest RSDs (less than 1%) and the best LODs (0.02, 0.2, 0.16, 0.11, 0.06, 0.05, 0.04, 0.14 and 0.09 mg L−1 for F−, Ac−, For−, Cl−, NO2−, Br−, NO3−, HPO42− and SO42−, respectively) were achieved using the IC SI-50 4E column. This column was applied for the separation of concerned ions in environmental precipitation samples such as snow, hail and rainwater. |
| 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 |
|
| Language |
|
Wos |
000266187600004 |
Publication Date |
2009-03-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0039-9140; 1873-3573 |
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:75475 |
Serial |
8542 |
| Permanent link to this record |
| |
|
| |
| Author |
Bittencourt, C.; van Lier, G.; Ke, X.; Suarez-Martinez, I.; Felten, A.; Ghijsen, J.; Van Tendeloo, G.; Ewels, C.O. |
| Title |
Spectroscopy and defect identification for fluorinated carbon nanotubes |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
ChemPhysChem : a European journal of chemical physics and physical chemistry |
Abbreviated Journal |
Chemphyschem |
| Volume |
10 |
Issue |
6 |
Pages |
920-925 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Multi-wall carbon nanotubes (MWCNTs) were exposed to a CF4 radio-frequency (rf) plasma. High-resolution photoelectron spectroscopy shows that the treatment effectively grafts fluorine atoms onto the MWCNTs, altering the valence electronic states. Fluorine surface concentration can be tuned by varying the exposure time. Evaporation of gold onto MWCNTs is used to mark active site formation. High-resolution transmission electron microscopy coupled with density functional theory (DFT) modelling is used to characterise the surface defects formed, indicating that the plasma treatment does not etch the tube surface. We suggest that this combination of theory and microscopy of thermally evaporated gold atoms onto the CNT surface may be a powerful approach to characterise both surface defect density as well as defect type. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000265469200011 |
Publication Date |
2009-03-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1439-4235;1439-7641; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.075 |
Times cited |
14 |
Open Access |
|
| Notes |
Iuap; Fwo |
Approved |
Most recent IF: 3.075; 2009 IF: 3.453 |
| Call Number |
UA @ lucian @ c:irua:77315 |
Serial |
3073 |
| Permanent link to this record |
| |
|
| |
| Author |
Georgieva, V.; Saraiva, M.; Jehanathan, N.; Lebelev, O.I.; Depla, D.; Bogaerts, A. |
| Title |
Sputter-deposited Mg-Al-O thin films: linking molecular dynamics simulations to experiments |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
| Volume |
42 |
Issue |
6 |
Pages |
065107,1-065107,8 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Using a molecular dynamics model the crystallinity of MgxAlyOz thin films with a variation in the stoichiometry of the thin film is studied at operating conditions similar to the experimental operating conditions of a dual magnetron sputter deposition system. The films are deposited on a crystalline or amorphous substrate. The Mg metal content in the film ranged from 100% (i.e. MgO film) to 0% (i.e. Al2O3 film). The radial distribution function and density of the films are calculated. The results are compared with x-ray diffraction and transmission electron microscopy analyses of experimentally deposited thin films by the dual magnetron reactive sputtering process. Both simulation and experimental results show that the structure of the MgAlO film varies from crystalline to amorphous when the Mg concentration decreases. It seems that the crystalline MgAlO films have a MgO structure with Al atoms in between. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000263824200024 |
Publication Date |
2009-03-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-3727;1361-6463; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.588 |
Times cited |
37 |
Open Access |
|
| Notes |
Iwt |
Approved |
Most recent IF: 2.588; 2009 IF: 2.083 |
| Call Number |
UA @ lucian @ c:irua:73246 |
Serial |
3110 |
| Permanent link to this record |
| |
|
| |
| Author |
Schattschneider, P.; Verbeeck, J.; Hamon, A.L. |
| Title |
Real space maps of atomic transitions |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
109 |
Issue |
7 |
Pages |
781-787 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Considering the rapid technical development of transmission electron microscopes, we investigate the possibility to map electronic transitions in real space on the atomic scale. To this purpose, we analyse the information carried by the scatterer's initial and final state wave functions and the role of the different atomic transition channels for the inelastic scattering cross section. It is shown that the change in the magnetic quantum number in the transition can be mapped. Two experimental set-ups are proposed, one blocking half the diffraction plane, the other one using a cylinder lens for imaging. Both methods break the conventional circular symmetry in the electron microscope making it possible to detect the handedness of electronic transitions as an asymmetry in the image intensity. This finding is of important for atomic resolution energy-loss magnetic chiral dichroism (EMCD), allowing to obtain the magnetic moments of single atoms. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000266787900002 |
Publication Date |
2009-03-01 |
| 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 |
10 |
Open Access |
|
| Notes |
J.V. acknowledges the FWO-Vlaanderen for support (contract no. G.0147.06) and the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
| Call Number |
UA @ lucian @ c:irua:77360UA @ admin @ c:irua:77360 |
Serial |
2829 |
| Permanent link to this record |
| |
|
| |
| Author |
de Backer, J.W.; Vos, W.G.; Germonpré, P.; Salgado, R.; Parizel, P.M.; de Backer, W. |
| Title |
Clinical applications of image-based airway computational fluid dynamics: assessment of inhalation medication and endobronchial devices |
Type |
A3 Journal article |
| Year |
2009 |
Publication |
Proceedings of the Society of Photo-optical Instrumentation Engineers |
Abbreviated Journal |
|
| Volume |
7262 |
Issue |
|
Pages |
72621p,1-72621p,9 |
| Keywords |
A3 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP) |
| Abstract |
Computational fluid dynamics (CFD) is a technique that is used increasingly in the biomedical field. Solving the flow equations numerically provides a convenient way to assess the efficiency of therapies and devices, ranging from cardiovascular stents and heart valves to hemodialysis workflows. Also in the respiratory field CFD has gained increasing interest, especially through the combination of three dimensional image reconstruction which results in highend patient-specific models. This paper provides an overview of clinical applications of CFD through image based modeling, resulting from recent studies performed in our center. We focused on two applications: assessment of the efficiency of inhalation medication and analysis of endobronchial valve placement. In the first application we assessed the mode of action of a novel bronchodilator in 10 treated patients and 4 controls. We assessed the local volume increase and resistance change based on the combination of imaging and CFD. We found a good correlation between the changes in volume and resistance coming from the CFD results and the clinical tests. In the second application we assessed the placement and effect of one way endobronchial valves on respiratory function in 6 patients. We found a strong patientspecific result of the therapy where in some patients the therapy resulted in complete atelectasis of the target lobe while in others the lobe remained inflated. We concluded from these applications that CFD can provide a better insight into clinically relevant therapies. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
2009-02-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:79497 |
Serial |
374 |
| Permanent link to this record |
| |
|
| |
| Author |
Damla, N.; Čevik, U.; Kobya, A.I.; Celik, A.; Van Grieken, R.; Kobya, Y. |
| Title |
Characterization of gas concrete materials used in buildings of Turkey |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
|
| Volume |
168 |
Issue |
2/3 |
Pages |
681-687 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The activity concentration of 226Ra, 232Th and 40K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg−1 for 226Ra, 232Th and 40K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg−1, equivalent to a gamma-dose of 1.5 mSv y−1. Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000268200700014 |
Publication Date |
2009-02-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3894 |
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:77256 |
Serial |
7621 |
| Permanent link to this record |
| |
|
| |
| Author |
Bultinck, E.; Mahieu, S.; Depla, D.; Bogaerts, A. |
| Title |
Reactive sputter deposition of TiNx films, simulated with a particle-in-cell/Monte Carlo collisions model |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
| Volume |
11 |
Issue |
|
Pages |
023039,1-023039,24 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
The physical processes in an Ar/N2 magnetron discharge used for the reactive sputter deposition of TiNx thin films were simulated with a 2d3v particle-in-cell/Monte Carlo collisions (PIC/MCC) model. Cathode currents and voltages were calculated self-consistently and compared with experiments. Also, ion fractions were calculated and validated with mass spectrometric measurements. With this PIC/MCC model, the influence of N2/Ar gas ratio on the particle densities and fluxes was investigated, taking into account the effect of the poisoned state of the target. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000263744100001 |
Publication Date |
2009-02-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.786 |
Times cited |
23 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.786; 2009 IF: 3.312 |
| Call Number |
UA @ lucian @ c:irua:73150 |
Serial |
2825 |
| Permanent link to this record |
| |
|
| |
| Author |
Caignaert, V.; Abakumov, A.M.; Pelloquin, D.; Pralong, V.; Maignan, A.; Van Tendeloo, G.; Raveau, B. |
| Title |
A new mixed-valence ferrite with a cubic structure, YBaFe4O7: spin-glass-like behavior |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
21 |
Issue |
6 |
Pages |
1116-1122 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A new mixed-valence ferrite, YBaFe4O7, has been synthesized. Its unique cubic structure, with a = 8.9595(2) Å, is closely related to that of the hexagonal 114 oxides YBaCo4O7 and CaBaFe4O7. It consists of corner-sharing FeO4 tetrahedra, forming triangular and kagome layers parallel to (111)C. In fact, the YBaFe4O7 and CaBaFe4O7 structures can be described as two different ccc and chch close packings of [BaO3]∞ and [O4]∞ layers, respectively, whose tetrahedral cavities are occupied by Fe2+/Fe3+ cations. The local structure of YBaFe4O7 is characterized by a large amount of stacking faults originating from the presence of hexagonal layers in the ccc cubic close-packed YBaFe4O7 structure. In this way, they belong to the large family of spinels and hexagonal ferrites studied for their magnetic properties. Differently from all the ferrites and especially from CaBaFe4O7, which are ferrimagnetic, YBaFe4O7 is an insulating spin glass with Tg = 50 K. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000264310900019 |
Publication Date |
2009-02-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.466 |
Times cited |
39 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 9.466; 2009 IF: 5.368 |
| Call Number |
UA @ lucian @ c:irua:76432 |
Serial |
2325 |
| Permanent link to this record |
| |
|
| |
| Author |
Stefaniak, E.A.; Alsecz, A.; Frost, R.; Máthé, Z.; Sajó, I.E.; Török, S.; Worobiec, A.; Van Grieken, R. |
| Title |
Combined SEM/EDX and micro-Raman spectroscopy analysis of uranium minerals from a former uranium mine |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
|
| Volume |
168 |
Issue |
1 |
Pages |
416-423 |
| Keywords |
A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Samples of the secondary uranium minerals collected in the abandoned uranium mine at Pecs (Hungary) were investigated by two micro-techniques: scanning electron microscopy (SEM/EDX) and micro-Raman spectroscopy (MRS). They were applied to locate U-rich particles and identify the chemical form and oxidation state of the uranium compounds. The most abundant mineral was a K and/or Na uranyl sulphate (zippeite group). U(VI) was also present in the form showing intensive Raman scattering at 860 cm−1 which can be attributed to uranium trioxide. This research has shown the successful application of micro-Raman spectroscopy for the identification of uranyl mineral species on the level of individual particles. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000267567600060 |
Publication Date |
2009-02-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3894 |
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:77032 |
Serial |
7681 |
| Permanent link to this record |
| |
|
| |
| Author |
Bharathy, M.; Gemmill, W.R.; Fox, A.H.; Darriet, J.; Smith, M.D.; Hadermann, J.; Remy, M.S.; zur Loye, H.-C. |
| Title |
Synthesis and magnetic properties of rare earth ruthenates, Ln5Ru2O12 (Ln=Pr, Nd, SmTb) |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| Volume |
182 |
Issue |
5 |
Pages |
1164-1170 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Single crystals of Ln5Ru2O12 (Ln=Pr, Nd, SmTb) were grown out of either NaOH or KOH fluxes in sealed silver tubes. The crystals of all the phases were observed to be twinned as confirmed by TEM studies. The series crystallize in the C2/m monoclinic system with lattice parameters, a=12.4049(4)12.7621(6) Å, b=5.8414(2)5.9488(3) Å, c=7.3489(2)7.6424(4) Å, β=107.425(3)107.432(2)° and Z=2. The crystal structure is isotypic with the defect/disorder model of Ln5Re2O12 (Ln = Y, Gd) and consists of one dimensional edge shared RuO6 octahedral chains separated by a two dimensional LnOx polyhedral framework. Magnetic measurements indicate paramagnetic and antiferromagnetic behavior for Ln=Nd, SmGd and Ln=Tb, respectively. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000265893700027 |
Publication Date |
2009-02-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.299 |
Times cited |
4 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.299; 2009 IF: 2.340 |
| Call Number |
UA @ lucian @ c:irua:77052 |
Serial |
3433 |
| Permanent link to this record |
| |
|
| |
| Author |
Lind, O.C.; Salbu, B.; Skipperud, L.; Janssens, K.; Jaroszewicz, J.; de Nolf, W. |
| Title |
Solid state speciation and potential bioavailability of depleted uranium particles from Kosovo and Kuwait |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of environmental radioactivity |
Abbreviated Journal |
J Environ Radioactiv |
| Volume |
100 |
Issue |
4 |
Pages |
301-307 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A combination of synchrotron radiation based X-ray microscopic techniques (ì-XRF, ì-XANES, ì-XRD) applied on single depleted uranium (DU) particles and semi-bulk leaching experiments has been employed to link the potential bioavailability of DU particles to site-specific particle characteristics. The oxidation states and crystallographic forms of U in DU particles have been determined for individual particles isolated from selected samples collected at different sites in Kosovo and Kuwait that were contaminated by DU ammunition during the 1999 Balkan conflict and the 1991 Gulf war. Furthermore, small soil or sand samples heavily contaminated with DU particles were subjected to simulated gastrointestinal fluid (0.16 M HCl) extractions. Characteristics of DU particles in Kosovo soils collected in 2000 and in Kuwait soils collected in 2002 varied significantly depending on the release scenario and to some extent on weathering conditions. Oxidized U (+6) was determined in large, fragile and bright yellow DU particles released during fire at a DU ammunition storage facility and crystalline phases such as schoepite (UO3·2.25H2O), dehydrated schoepite (UO3·0.75H2O) and metaschoepite (UO3·2.0H2O) were identified. As expected, these DU particles were rapidly dissolved in 0.16 M HCl (84 ± 3% extracted after 2 h) indicating a high degree of potential mobility and bioavailability. In contrast, the 2 h extraction of samples contaminated with DU particles originating either from corrosion of unspent DU penetrators or from impacted DU ammunition appeared to be much slower (2030%) as uranium was less oxidized (+4 to +6). Crystalline phases such as UO2, UC and metallic U or UTi alloy were determined in impacted DU particles from Kosovo and Kuwait, while the UO2,34 phase, only determined in particles from Kosovo, could reflect a more corrosive environment. Although the results are based on a limited number of DU particles, they indicate that the structure and extractability of DU particles released from similar sources (metallic U penetrators) will depend on the release scenarios (fire, impact) and to some extent environmental conditions. However, most of the DU particles (7396%) in all investigated samples were dissolved in 0.16 M HCl after one week indicating that a majority of the DU material is bioaccessible. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000264649500004 |
Publication Date |
2009-02-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0265-931x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.31 |
Times cited |
49 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.31; 2009 IF: 1.268 |
| Call Number |
UA @ admin @ c:irua:76413 |
Serial |
5834 |
| Permanent link to this record |
| |
|
| |
| Author |
Lin, K.; Pescarmona, P.P.; Houthoofd, K.; Liang, D.; Van Tendeloo, G.; Jacobs, P.A. |
| Title |
Direct room-temperature synthesis of methyl-functionalized Ti-MCM-41 nanoparticles and their catalytic performance in epoxidation |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
| Volume |
263 |
Issue |
1 |
Pages |
75-82 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Methyl-functionalized Ti-MCM-41 nanoparticles with a size of 80 to 160 nm (Me-Ti-MCM-41 NP) were directly prepared via a dilute solution route by the co-condensation of tetraethoxysilane and methylalkoxysilanes in sodium hydroxide medium at room temperature. The characterization results showed the existence of ordered hexagonal mesoporous structure and tetrahedral Ti species in the nanoparticles. In the epoxidation of cyclohexene with tert-butyl hydroperoxide and aqueous H2O2, Me-Ti-MCM-41 NP samples displayed higher turnover frequencies (TOFs) for cyclohexene and initial reaction rates compared to Ti-MCM-41 and methyl-functionalized Ti-MCM-41 with normal particle size and to non-functionalized Ti-MCM-41 nanoparticles. Simultaneously, a higher selectivity for cyclohexene epoxide was observed in the case of aqueous H2O2, suggesting that the hydrolysis of cyclohexene epoxide with water is reduced on Me-Ti-MCM-41 NP samples. The improved catalytic behavior of Me-Ti-MCM-41 NP is discussed both in terms of the nanosize and methylation of the surface of the catalyst particles. The regeneration of Me-Ti-MCM-41 NP with tert-butyl hydroperoxide solution was evaluated via washing and calcination approaches. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
San Diego, Calif. |
Editor |
|
| Language |
|
Wos |
000265000800008 |
Publication Date |
2009-02-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-9517; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.844 |
Times cited |
89 |
Open Access |
|
| Notes |
Iwt; Iap; Goa |
Approved |
Most recent IF: 6.844; 2009 IF: 5.288 |
| Call Number |
UA @ lucian @ c:irua:76395 |
Serial |
720 |
| Permanent link to this record |
| |
|
| |
| Author |
Karabidak, S.M.; Čevik, U.; Kaya, S. |
| Title |
A new method to compensate for counting losses due to system dead time |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Nuclear instruments and methods in physics research : A: accelerators, spectrometers, detectors and associated equipment |
Abbreviated Journal |
|
| Volume |
603 |
Issue |
3 |
Pages |
361-364 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Determination of count losses and pile-up pulse effects in quantitative and qualitative analysis became a vital step in various analyses. Therefore, compensating for counting losses is of importance. These counting losses are due to the pulse pile-up, paralyzable and non-paralyzable system dead time or a combination of these mechanisms. In this work, a new method is suggested for the correction of dead time losses resulting from the above mechanisms. For this purpose, a source code was developed. It was found that the peaking time was an important parameter over system dead time. The method suggested seems to be more effective even at high count rate. (C) 2009 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 |
|
Editor |
|
| Language |
|
Wos |
000266829400021 |
Publication Date |
2009-02-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0168-9002 |
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:94550 |
Serial |
8304 |
| Permanent link to this record |
| |
|
| |
| Author |
Werner, R.; Raisch, C.; Leca, V.; Ion, V.; Bals, S.; Van Tendeloo, G.; Chasse, T.; Kleiner, R.; Koelle, D. |
| Title |
Transport, magnetic, and structural properties of La0.7Ce0.3MnO3 thin films: evidence for hole-doping |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
5 |
Pages |
054416,1-054416,8 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Cerium-doped manganite thin films were grown epitaxially by pulsed laser deposition at 720 °C and oxygen pressure pO2=125 Pa and were subjected to different annealing steps. According to x-ray diffraction (XRD) data, the formation of CeO2 as a secondary phase could be avoided for pO28 Pa. However, transmission electron microscopy shows the presence of CeO2 nanoclusters even in those films which appear to be single phase in XRD. With O2 annealing, the metal-to-insulator transition temperature increases, while the saturation magnetization decreases and stays well below the theoretical value for electron-doped La0.7Ce0.3MnO3 with mixed Mn3+/Mn2+ valences. The same trend is observed with decreasing film thickness from 100 to 20 nm, indicating a higher oxygen content for thinner films. Hall measurements on a film which shows a metal-to-insulator transition clearly reveal holes as dominating charge carriers. Combining data from x-ray photoemission spectroscopy, for determination of the oxygen content, and x-ray absorption spectroscopy (XAS), for determination of the hole concentration and cation valences, we find that with increasing oxygen content the hole concentration increases and Mn valences are shifted from 2+ to 4+. The dominating Mn valences in the films are Mn3+ and Mn4+, and only a small amount of Mn2+ ions can be observed by XAS. Mn2+ and Ce4+ XAS signals obtained in surface-sensitive total electron yield mode are strongly reduced in the bulk-sensitive fluorescence mode, which indicates hole-doping in the bulk for those films which do show a metal-to-insulator transition. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000263815400057 |
Publication Date |
2009-02-13 |
| 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 |
25 |
Open Access |
|
| Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:76221 |
Serial |
3725 |
| Permanent link to this record |
| |
|
| |
| Author |
Xu, W.; Peeters, F.M.; Lu, T.C. |
| Title |
Dependence of resistivity on electron density and temperature in graphene |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
7 |
Pages |
073403,1-073403,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
On the basis of the momentum-balance equation derived from the Boltzmann equation in which electron interactions with impurities and acoustic and optic phonons are included, we examine the dependence of the resistivity in graphene on temperature and electron density. Simple analytical expressions for the different contributions to the resistivity are obtained. Our results reproduce recent experimental findings and we are able to understand the different temperature dependence of the resistivity for low and high density samples. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000263815800013 |
Publication Date |
2009-02-12 |
| 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 |
31 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:76222 |
Serial |
642 |
| Permanent link to this record |
| |
|
| |
| Author |
Kalina, R.; Szafran, B.; Bednarek, S.; Peeters, F.M. |
| Title |
Magnetic-field asymmetry of electron wave packet transmission in bent channels capacitively coupled to a metal gate |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
102 |
Issue |
6 |
Pages |
066807,1-066807,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study the electron wave packet moving through a bent channel. We demonstrate that the packet transmission probability becomes an asymmetric function of the magnetic field when the electron packet is capacitively coupled to a metal plate. The coupling occurs through a nonlinear potential which translates a different kinetics of the transport for opposite magnetic-field orientations into a different potential felt by the scattered electron. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000263389500056 |
Publication Date |
2009-02-12 |
| 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 |
14 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 8.462; 2009 IF: 7.328 |
| Call Number |
UA @ lucian @ c:irua:76315 |
Serial |
1867 |
| Permanent link to this record |
| |
|
| |
| Author |
Suarez-Martinez, I.; Bittencourt, C.; Ke, X.; Felten, A.; Pireaux, J.J.; Ghijsen, J.; Drube, W.; Van Tendeloo, G.; Ewels, C.P. |
| Title |
Probing the interaction between gold nanoparticles and oxygen functionalized carbon nanotubes |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
| Volume |
47 |
Issue |
6 |
Pages |
1549-1554 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The interaction between evaporated gold and pristine or oxygen plasma treated multi-walled carbon nanotubes (MWCNTs) is investigated. Experimental and theoretical results indicate that gold nucleation occurs at defect sites, whether initially present or introduced by oxygen plasma treatment. Uniform gold cluster dispersion is observed on plasma treated carbon nanotubes (CNTs) and associated with the presence of uniformly dispersed oxidized vacancy centres on the CNT surface. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000265518700018 |
Publication Date |
2009-02-11 |
| 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 |
38 |
Open Access |
|
| Notes |
Pai |
Approved |
Most recent IF: 6.337; 2009 IF: 4.504 |
| Call Number |
UA @ lucian @ c:irua:77267 |
Serial |
2717 |
| Permanent link to this record |
| |
|
| |
| Author |
Idrissi, H.; Ryelandt, L.; Veron, M.; Schryvers, D.; Jacques, P.J. |
| Title |
Is there a relationship between the stacking fault character and the activated mode of plasticity of FeMn-based austenitic steels? |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
| Volume |
60 |
Issue |
11 |
Pages |
941-944 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
By changing the testing temperature, an austenitic FeMnAlSi alloy presents either å-martensite transformation or mechanical twinning during straining. In order to understand the nucleation and growth mechanisms involved in both phenomena, defects and particularly stacking faults, were characterized by transmission electron microscopy. It is observed that the character of the stacking faults also changes (from extrinsic to intrinsic) together with the temperature and the activated mode of plasticity. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000265359900005 |
Publication Date |
2009-02-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6462; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.747 |
Times cited |
84 |
Open Access |
|
| Notes |
Iap |
Approved |
Most recent IF: 3.747; 2009 IF: 2.949 |
| Call Number |
UA @ lucian @ c:irua:77276 |
Serial |
1751 |
| Permanent link to this record |
| |
|
| |
| Author |
Li, B.; Partoens, B.; Peeters, F.M.; Magnus, W. |
| Title |
Dielectric mismatch effect on coupled shallow impurity states in a semiconductor nanowire |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
8 |
Pages |
085306,1-085306,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Coupled shallow impurity states in a freestanding semiconductor nanowire and in a semiconductor nanowire surrounded by a metallic gate are studied within the effective-mass approximation. Bonding and antibonding states are found due to the coupling of the two impurities, and their energy converges with increasing distance di between the two impurities. The dependences of the binding energy on the wire radius R, the distance di between the two impurities, and the impurity radial position in the nanowire are examined. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000263816000051 |
Publication Date |
2009-02-09 |
| 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 |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:76223 |
Serial |
691 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Tendeloo, G.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V. |
| Title |
Advanced electron microscopy and its possibilities to solve complex structures: application to transition metal oxides |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
| Volume |
19 |
Issue |
18 |
Pages |
2660-2670 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Design and optimization of materials properties can only be performed through a thorough knowledge of the structure of the compound. In this feature article we illustrate the possibilities of advanced electron microscopy in materials science and solid state chemistry. The different techniques are briefly discussed and several examples are given where the structures of complex oxides, often with a modulated structure, have been solved using electron microscopy. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000265740600002 |
Publication Date |
2009-02-04 |
| 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 |
9 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:77065 |
Serial |
68 |
| Permanent link to this record |
| |
|
| |
| Author |
Slachmuylders, A.F.; Partoens, B.; Magnus, W.; Peeters, F.M. |
| Title |
Neutral shallow donors near a metallic interface |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Microelectronics journal |
Abbreviated Journal |
Microelectron J |
| Volume |
40 |
Issue |
4/5 |
Pages |
753-755 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The effect of a metallic gate on the bound states of a shallow donor located near the gate is studied. We calculate the energy spectrum as a function of the distance between the metallic gate and the donor and find an anti-crossing behavior in the energy levels for certain distances. We show how a transverse electric field can tune the average position of the electron with respect to the metallic gate and the impurity. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Luton |
Editor |
|
| Language |
|
Wos |
000265870200024 |
Publication Date |
2009-02-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0026-2692; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.163 |
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.163; 2009 IF: 0.778 |
| Call Number |
UA @ lucian @ c:irua:77029 |
Serial |
2296 |
| Permanent link to this record |
| |
|
| |
| Author |
Kolev, I.; Bogaerts, A. |
| Title |
Numerical study of the sputtering in a dc magnetron |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of vacuum science and technology: A: vacuum surfaces and films |
Abbreviated Journal |
J Phys Chem C |
| Volume |
27 |
Issue |
1 |
Pages |
20-28 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Molecular dynamics simulations were used to investigate the size-dependent melting mechanism of nickel nanoclusters of various sizes. The melting process was monitored by the caloric curve, the overall cluster Lindemann index, and the atomic Lindemann index. Size-dependent melting temperatures were determined, and the correct linear dependence on inverse diameter was recovered. We found that the melting mechanism gradually changes from dynamic coexistence melting to surface melting with increasing cluster size. These findings are of importance in better understanding carbon nanotube growth by catalytic chemical vapor deposition as the phase state of the catalyst nanoparticle codetermines the growth mechanism. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000263299600018 |
Publication Date |
2009-02-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.536 |
Times cited |
66 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.536; 2009 IF: 4.224 |
| Call Number |
UA @ lucian @ c:irua:71634 |
Serial |
2411 |
| Permanent link to this record |
| |
|
| |
| Author |
Batenburg, K.J.; Bals, S.; Sijbers, J.; Kübel, C.; Midgley, P.A.; Hernandez, J.C.; Kaiser, U.; Encina, E.R.; Coronado, E.A.; Van Tendeloo, G. |
| Title |
3D imaging of nanomaterials by discrete tomography |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
109 |
Issue |
6 |
Pages |
730-740 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
The field of discrete tomography focuses on the reconstruction of samples that consist of only a few different materials. Ideally, a three-dimensional (3D) reconstruction of such a sample should contain only one grey level for each of the compositions in the sample. By exploiting this property in the reconstruction algorithm, either the quality of the reconstruction can be improved significantly, or the number of required projection images can be reduced. The discrete reconstruction typically contains fewer artifacts and does not have to be segmented, as it already contains one grey level for each composition. Recently, a new algorithm, called discrete algebraic reconstruction technique (DART), has been proposed that can be used effectively on experimental electron tomography datasets. In this paper, we propose discrete tomography as a general reconstruction method for electron tomography in materials science. We describe the basic principles of DART and show that it can be applied successfully to three different types of samples, consisting of embedded ErSi2 nanocrystals, a carbon nanotube grown from a catalyst particle and a single gold nanoparticle, respectively. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000265816400005 |
Publication Date |
2009-02-01 |
| 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 |
220 |
Open Access |
|
| Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.843; 2009 IF: 2.067 |
| Call Number |
UA @ lucian @ c:irua:74665 c:irua:74665 |
Serial |
12 |
| Permanent link to this record |
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| |
| Author |
Avetisyan, A.A.; Partoens, B.; Peeters, F.M. |
| Title |
Electric field tuning of the band gap in graphene multilayers |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
3 |
Pages |
035421,1-035421,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A perpendicular electric field applied to multilayers of graphene modifies the electronic structure near the K point and may induce an energy gap in the electronic spectrum. This gap is tunable by the gate voltage and its size depends on the number of layers. We use a tight-binding approach to calculate the band structure and include a self-consistent calculation in order to obtain the density of charge carriers. Results are presented for systems consisting of three and four layers of graphene. The effect of the circular asymmetry of the band structure on the gap is critically examined. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000262978200119 |
Publication Date |
2009-01-30 |
| 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 |
106 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:75984 |
Serial |
887 |
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| |
| Author |
Misko, V.R.; Zhao, H.J.; Peeters, F.M.; Oboznov, V.; Dubonos, S.V.; Grigorieva, I.V. |
| Title |
Formation of vortex shells in mesoscopic superconducting squares |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
| Volume |
22 |
Issue |
3 |
Pages |
034001,1-034001,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study vortex configurations in mesoscopic superconducting squares. Our theoretical approach is based on the analytical solution of the London equation using the Green's function method. The potential energy landscape found is then used in Langevin-type molecular-dynamics simulations to obtain stable vortex configurations. We show that the filling rules for vortices in squares with increasing applied magnetic field can be formulated, although in a different manner than in disks, in terms of the formation of vortex 'shells'. We discuss metastable states and the stability of the vortex configurations found with respect to variations of the material parameters and deformations of the shape of the sample. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000263564500002 |
Publication Date |
2009-01-29 |
| 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 |
14 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.878; 2009 IF: 2.694 |
| Call Number |
UA @ lucian @ c:irua:76312 |
Serial |
1267 |
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| Author |
Koblischka, M.R.; Winter, M.; Das, P.; Koblischka-Veneva, A.; Muralidhar, M.; Wolf, T.; Babu, N.H.; Turner, S.; Van Tendeloo, G.; Hartmann, U. |
| Title |
Observation of nanostripes and -clusters in (Nd, EuGd)Ba2Cu3Ox superconductors |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
469 |
Issue |
4 |
Pages |
168-176 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Nanostripes are observed in melt-textured and single-crystalline samples of the ternary light rare earth (LRE)-compound (Nd0.33Eu0.33Gd0.33)Ba2Cu3Ox (NEG) by means of atomic force microscopy, scanning tunnelling microscopy at ambient conditions, combined with transmission electron microscopy and electron backscatter diffraction. This enables the observation of several important features: The nanostripes are formed by chains of nanoclusters, representing the LRE/Ba substitution. The dimensions of the nanostripes are similar for both types of NEG samples. The periodicity of the nanostripes is found to range between 40 and 60 nm; the shape of the nanoclusters is elliptic with a major axis length between 300 and 500 nm and a minor axis length of about 30150 nm. The stripes are filling effectively the space in between the twin boundaries. Concerning the flux pinning, the nanoclusters are the important pinning sites, not the nanostripes themselves. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000264657100008 |
Publication Date |
2009-01-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
6 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.404; 2009 IF: 0.723 |
| Call Number |
UA @ lucian @ c:irua:76403 |
Serial |
2418 |
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| Author |
Marguí, E.; van Meel, K.; Van Grieken, R.; Buendía, A.; Fontás, C.; Hidalgo, M.; Queralt, I. |
| Title |
Method for the determination of Pd-catalyst residues in active pharmaceutical ingredients by means of high-energy polarized-beam energy dispersive X-ray fluorescence |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Analytical chemistry |
Abbreviated Journal |
|
| Volume |
81 |
Issue |
4 |
Pages |
1404-1410 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
In medicinal chemistry, Pd is perhaps the most-widely utilized precious metal, as catalyst in reactions which represent key transformations toward the synthesis of new active pharmaceutical ingredients (APIs). The disadvantage of this metal-catalyzed chemistry is that expensive and toxic metal residues are invariably left bound to the desired product. Thus, stringent regulatory guidelines exist for the amount of residual Pd that a drug candidate is allowed to contain. In this work, a rapid and simple method for the determination of Pd in API samples by high-energy polarized-beam energy dispersive X-ray fluorescence spectrometry has been developed and validated according to the specification limits of current legislation (10 mg kg−1 Pd) and the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH guidelines). Sample and calibration standards preparation includes a first step of homogenization and then, in a second step, the pressing of the powdered material into pellets without any chemical treatment. The use of several synthetic calibration standards made of cellulose to simulate the API matrix appears to be an effective means to obtain reliable calibration curves with a good spread of data points over the working range. With the use of the best measuring conditions, the limit of detection (0.11 mg kg−1 Pd) as well as the limit of quantitation (0.37 mg kg−1 Pd) achieved meet rigorous requirements. The repeatability of the XRF measurement appeared to be less than 2%, while the precision of the whole method was around 7%. Trueness was evaluated by analyzing spiked API samples at the level of the specification limit and calculating the recovery factor, which was better than 95%. To study the applicability of the developed methodology for the intended purpose, three batches of the studied API were analyzed for their Pd content, and the attained results were comparable to those obtained by the daily routine method (acid digestion plus atomic spectroscopy) used in most pharmaceutical laboratories. |
| 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 |
000263319000015 |
Publication Date |
2009-01-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-2700; 5206-882x |
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:74340 |
Serial |
8220 |
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| Author |
Esken, D.; Zhang, X.; Lebedev, O.I.; Schröder, F.; Fischer, R.A. |
| Title |
Pd@MOF-5: limitations of gas-phase infiltration and solution impregnation of [Zn4O(bdc)3] (MOF-5) with metalorganic palladium precursors for loading with Pd nanoparticles |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
| Volume |
19 |
Issue |
9 |
Pages |
1314-1319 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The limitations of the loading of the porous metalorganic framework [Zn4O(bdc)3] (bdc = benzene-1,4-dicarboxylate; MOF-5 or IRMOF-1) with Pd nanoparticles was investigated. First, the volatile organometallic precursor [Pd(5-C5H5)(3-C3H5)] was employed to get the inclusion compound [Pd(5-C5H5)(3-C3H5)]x@MOF-5 via gas-phase infiltration at 10-3 mbar. A loading of four molecules of [Pd(5-C5H5)(3-C3H5)] per formula unit of MOF-5 (x = 4) can be reached (35 wt.% Pd). Second, the metalorganic precursor [Pd(acac)2] (acac = 2,4-pentanedionate) was used and the inclusion materials [Pd(acac)2]x@MOF-5 of different Pd loadings were obtained by incipient wetness infiltration. However, the maximum loading was lower as compared with the former case with about two precursor molecules per formula unit of MOF-5. Both loading routes are suitable for the synthesis of Pd nanoparticles inside the porous host matrix. Homogeneously distributed nanoparticles with diameter of 2.4(±0.2) nm can be achieved by photolysis of the inclusion compounds [Pd(5-C5H5)(3-C3H5)]x@MOF-5 (x 4), while the hydrogenolysis of [Pd(acac)2]x@MOF-5 (x 2) leads to a mixture of small particles inside the network (< 3 nm) and large Pd agglomerates (40 nm) on the outer surface of the MOF-5 specimens. The pure Pdx@MOF-5 materials proved to be stable under hydrogen pressure (2 bar) at 150 °C over many hours. Neither hydrogenation of the bdc linkers nor particle growth was observed. The new composite materials were characterized by 1H/13C-MAS-NMR, powder XRD, ICP-AES, FT-IR, N2 sorption measurements and high resolution TEM. Raising the Pd loading of a representative sample Pd4@MOF-5 (35 wt.% Pd) by using [Pd(5-C5H5)(3-C3H5)] as precursor in a second cycle of gas-phase infiltration and photolysis was accompanied by the collapse of the long-range crystalline order of the MOF. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000263450300015 |
Publication Date |
2009-01-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
100 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:76318 |
Serial |
2565 |
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| Author |
Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M. |
| Title |
Composite vortex ordering in superconducting films with arrays of blind holes |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
| Volume |
11 |
Issue |
|
Pages |
013025,1-013025,20 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The pinning properties of a superconducting thin film with a square array of blind holes are studied using the nonlinear GinzburgLandau theory. Although blind holes provide a weaker pinning potential than holes (also called antidots), several novel vortex structures are predicted for different size and thickness of the blind holes. Orientational dimer and trimer vortex states as well as concentric vortex shells can nucleate in the blind holes. In addition, we predict the stabilization of giant vortices that may be located both in the pinning centers and/or at the interstitial sites, as well as the combination of giant vortices with sets of individual vortices. For large blind holes, local vortex shell structures inside the blind holes may transfer their symmetry to interstitial vortices as well. The subtle interplay of shell formation and traditional Abrikosov vortex lattices inside the blind holes is also studied for different numbers of trapped vortices. |
| Address |
|
| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000262932600002 |
Publication Date |
2009-01-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.786 |
Times cited |
33 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.786; 2009 IF: 3.312 |
| Call Number |
UA @ lucian @ c:irua:75987 |
Serial |
441 |
| Permanent link to this record |
