| Records |
| Author |
de Maeyer-Worobiec, A.; Dekov, V.M.; Laane, R.W.P.M.; Van Grieken, R. |
| Title |
EPXMA survey of shelf sediments (Southern Bight, North Sea): a glance beyond the XRD-invisible |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Microchemical journal |
Abbreviated Journal |
|
| Volume |
91 |
Issue |
1 |
Pages |
21-31 |
| Keywords |
A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Shelf sediments of the southern North Sea, were studied with a microanalytical [electron probe X-ray microanalysis (EPXMA)] and two bulk [X-ray diffraction (XRD) and X-ray fluorescence (XRF)] techniques. The investigation proved that the promptness of the microanalytical method is combined with a reasonable analytical reliability. XRD studies of such a type of sediments with monotonous mineral composition are not able to provide mineralogical information beyond the main well-crystalline minerals and the mineralogical quantitative characteristic of the sediment based on XRD estimations are incorrect. The EPXMA mineralogical interpretations are based on the statistical evaluation of a huge data set (thousands of mineral particles) and provide a rather correct quantitative determination of the main minerals. The comparative EPXMAXRF study revealed that the Al, Si, K, Ca, Fe and to some extent Ti contents estimated by EPXMA are fairly reliable. In this respect the accuracy of the EPXMA-based mineral identification of the pure silicates, pure aluminosilicates, and Al-, Ca-, Fe- and Ti-containing minerals with simple composition is very high. Mg-calcite, augite and apatite determinations are assessed to be correct. The supposed accuracy of the clay mineral determinations is slightly lower (7080%) than that of the other main minerals due to the complex and varying composition of the clays. The identification of XRD-invisible accessory minerals and quantification of their presence in the sediments is an essential advantage of the EPXMA, which makes it a useful approach in tracing the origin of the sediments, the pathways of their transport and the geochemical processes they have undergone. However, the EPXMA has several flaws, which need to be solved in the future sediment investigations: (1) calibration with natural standards is needed in order to provide a higher accuracy of the mineral determinations; (2) any EPXMA study of sediments needs to be secured with XRF examinations of selected samples since EPXMA gives only semi-quantitative information about the abundance of the elements; (3) ultra-thin window EPXMA of low-Z elements has to be used since some of them (O, C) are always present in the main sediment components: silicates, aluminosilicates, carbonates and metal oxyhydroxides; (4) the interpretations of the clay fraction have to be supported with detailed XRD investigations of selected samples, while the mineralogy of the silt and sand fractions needs to be backed up with optical microscopy studies. The information from different analytical techniques (EPXMA with XRFXRD-optical microscopy of selected samples) combined with the knowledge about the most possible minerals in a given environment, would give the most reliable results in studying mineralogical composition of shelf sediments. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos  |
000262963300006 |
Publication Date |
2008-07-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0026-265x; 0026-265x |
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:71604 |
Serial |
7933 |
| Permanent link to this record |
| |
|
| |
| Author |
Pogosov, W.V.; Misko, V.R.; Zhao, H.J.; Peeters, F.M. |
| Title |
Collective vortex phases in periodic plus random pinning potential |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
1 |
Pages |
014504,1-014504,12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study theoretically the simultaneous effect of regular and random pinning potentials on the vortex lattice structure at filling factor of 1. This structure is determined by a competition between the square symmetry of regular pinning array, by the intervortex interaction favoring a triangular symmetry, and by the randomness trying to depin vortices from their regular positions. Both analytical and molecular-dynamics approaches are used. We construct a phase diagram of the system in the plane of regular and random pinning strengths and determine typical vortex lattice defects appearing in the system due to the disorder. We find that the total disordering of the vortex lattice can occur either in one step or in two steps. For instance, in the limit of weak pinning, a square lattice of pinned vortices is destroyed in two steps. First, elastic chains of depinned vortices appear in the film; but the vortex lattice as a whole remains still pinned by the underlying square array of regular pinning sites. These chains are composed into fractal-like structures. In a second step, domains of totally depinned vortices are generated and the vortex lattice depins from regular array. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000262977900092 |
Publication Date |
2009-01-06 |
| 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 |
14 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:75982 |
Serial |
386 |
| Permanent link to this record |
| |
|
| |
| Author |
Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. |
| Title |
Tunneling, conductance, and wavevector filtering through magnetic barriers in bilayer graphene |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
| Volume |
79 |
Issue |
3 |
Pages |
035409,1-035409,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We evaluate the transmission and conductance through magnetic barrier structures in bilayer graphene. In particular we consider a magnetic step, single and double barriers, -function barriers, as well as barrier structures that have average magnetic field equal to zero. The transmission depends strongly on the direction of the incident electron or hole wavevector and gives the possibility to construct a direction-dependent wavevector filter. The results contrast sharply with previous results on single-layer graphene. In general, the angular range of perfect transmission becomes drastically wider and the gaps narrower. This perfect transmission range decreases with the number of barriers, the barrier width, and the magnetic field. Depending on the structure, a variety of transmission resonances occur that are reflected in the conductance through the structure. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000262978200107 |
Publication Date |
2009-01-14 |
| 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 |
80 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
| Call Number |
UA @ lucian @ c:irua:75983 |
Serial |
3762 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| 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 |
| Permanent link to this record |
| |
|
| |
| Author |
d' Hondt, H.; Hadermann, J.; Abakumov, A.M.; Kalyuzhnaya, A.S.; Rozova, M.G.; Tsirlin, A.A.; Tan, H.; Verbeeck, J.; Antipov, E.V.; Van Tendeloo, G. |
| Title |
Synthesis, crystal structure and magnetic properties of the Sr2Al0.78Mn1.22O5.2 anion-deficient layered perovskite |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
| Volume |
182 |
Issue |
2 |
Pages |
356-363 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A new layered perovskite Sr2Al0.78Mn1.22O5.2 has been synthesized by solid state reaction in a sealed evacuated silica tube. The crystal structure has been determined using electron diffraction, high-resolution electron microscopy, and high-angle annular dark field imaging and refined from X-ray powder diffraction data (space group P4/mmm, a=3.89023(5) Å, c=7.8034(1) Å, RI=0.023, RP=0.015). The structure is characterized by an alternation of MnO2 and (Al0.78Mn0.22)O1.2 layers. Oxygen atoms and vacancies, as well as the Al and Mn atoms in the (Al0.78Mn0.22)O1.2 layers are disordered. The local atomic arrangement in these layers is suggested to consist of short fragments of brownmillerite-type tetrahedral chains of corner-sharing AlO4 tetrahedra interrupted by MnO6 octahedra, at which the chain fragments rotate over 90°. This results in an averaged tetragonal symmetry. This is confirmed by the valence state of Mn measured by EELS. The relationship between the Sr2Al0.78Mn1.22O5.2 tetragonal perovskite and the parent Sr2Al1.07Mn0.93O5 brownmillerite is discussed. Magnetic susceptibility measurements indicate spin glass behavior of Sr2Al0.78Mn1.22O5.2. The lack of long-range magnetic ordering contrasts with Mn-containing brownmillerites and is likely caused by the frustration of interlayer interactions due to presence of the Mn atoms in the (Al0.78Mn0.22)O1.2 layers. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000263124700022 |
Publication Date |
2008-11-14 |
| 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 |
12 |
Open Access |
|
| Notes |
Iap Vi |
Approved |
Most recent IF: 2.299; 2009 IF: 2.340 |
| Call Number |
UA @ lucian @ c:irua:72943 |
Serial |
3450 |
| Permanent link to this record |
| |
|
| |
| Author |
Bervoets, A.R.J.; Behets, G.J.; Schryvers, D.; Roels, F.; Yang, Z.; Verberckmoes, S.C.; Damment, S.J.P.; Dauwe, S.; Mubiana, V.K.; Blust, R.; de Broe, M.E.; d' Haese, P.C. |
| Title |
Hepatocellular transport and gastrointestinal absorption of lanthanum in chronic renal failure |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Kidney international |
Abbreviated Journal |
Kidney Int |
| Volume |
75 |
Issue |
|
Pages |
389-398 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Pathophysiology |
| Abstract |
Lanthanum carbonate is a new phosphate binder that is poorly absorbed from the gastrointestinal tract and eliminated largely by the liver. After oral treatment, we and others had noticed 23 fold higher lanthanum levels in the livers of rats with chronic renal failure compared to rats with normal renal function. Here we studied the kinetics and tissue distribution, absorption, and subcellular localization of lanthanum in the liver using transmission electron microscopy, electron energy loss spectrometry, and X-ray fluoresence. We found that in the liver lanthanum was located in lysosomes and in the biliary canal but not in any other cellular organelles. This suggests that lanthanum is transported and eliminated by the liver via a transcellular, endosomal-lysosomal-biliary canicular transport route. Feeding rats with chronic renal failure orally with lanthanum resulted in a doubling of the liver levels compared to rats with normal renal function, but the serum levels were similar in both animal groups. These levels plateaued after 6 weeks at a concentration below 3 g/g in both groups. When lanthanum was administered intravenously, thereby bypassing the gastrointestinal tract-portal vein pathway, no difference in liver levels was found between rats with and without renal failure. This suggests that there is an increased gastrointestinal permeability or absorption of oral lanthanum in uremia. Lanthanum levels in the brain and heart fluctuated near its detection limit with long-term treatment (20 weeks) having no effect on organ weight, liver enzyme activities, or liver histology. We suggest that the kinetics of lanthanum in the liver are consistent with a transcellular transport pathway, with higher levels in the liver of uremic rats due to higher intestinal absorption. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000263145800009 |
Publication Date |
2008-12-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0085-2538;1523-1755; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
8.395 |
Times cited |
29 |
Open Access |
|
| Notes |
Fwo; Iwt |
Approved |
Most recent IF: 8.395; 2009 IF: 6.193 |
| Call Number |
UA @ lucian @ c:irua:72290 |
Serial |
1417 |
| Permanent link to this record |
| |
|
| |
| Author |
Celik, N.; Čevik, U.; Celik, A.; Koz, B. |
| Title |
Natural and artificial radioactivity measurements in Eastern Black Sea region of Turkey |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
|
| Volume |
162 |
Issue |
1 |
Pages |
146-153 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
In the present work, naturally occurring radionuclides of (226)Ra, (232)Th and (40)K were measured in soil samples collected from the Eastern Black Sea region of Turkey. It was found that the activity concentrations ranged from 12 to 120 Bq kg(-1) for (226)Ra, from 13 to 121 Bq kg(-1) for (232)Th and from 204 to 1295 Bq kg(-1) for (40)K. Besides naturally occurring radionuclides, (137)Cs activity concentration was measured in soil, lichen and moss samples and it was found that (137)Cs activity concentration ranged from 27 to 775 Bq kg(-1) with for soil, from 29 to 879 Bq kg(-1) for lichen and from 67 to 1396 Bq kg(-1) for moss samples. Annual effective doses due to the naturally occurring radionuclides and (137)CS were estimated. Ecological half-lives of (137)CS in lichen and moss species were estimated. The decrease of the activity concentrations in the present measurements (2007) relative to those in 1993 indicated ecological half-lives between 1.36 and 2.96 years for lichen and between 1.35 and 2.85 years for moss species. (C) 2008 Elsevier B.V. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000263149400019 |
Publication Date |
2008-05-10 |
| 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:94562 |
Serial |
8296 |
| Permanent link to this record |
| |
|
| |
| Author |
Stranger, M.; Potgieter-Vermaak, S.; Sacco, P.; Quaglio, F.; Pagani, D.; Cocheo, C.; Godoi, A.F.L.; Van Grieken, R. |
| Title |
Analysis of indoor gaseous formic and acetic acid, using radial diffusive samplers |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Environmental monitoring and assessment |
Abbreviated Journal |
|
| Volume |
149 |
Issue |
|
Pages |
411-417 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A diffusive sampling method for the determination of gaseous acetic and formic acids, using a radial symmetry diffusive sampler, has been optimised for a 7-day exposure time in this study. Sampling rate determinations were performed on data obtained from a dynamic exposure chamber, simulating the indoor conditions of an empty, closed, room, at room temperature and minimal wind speed. Analysis has been performed by means of ion chromatography. The sampling rates for formic acid concentrations of 128 ìg m−3 and 1248 ìg m−3 were determined to be 91.2 ± 3.9 ml min−1 and 111.6 ± 2.8 ml min−1, respectively. The acetic acid sampling rate was independent of the concentration in the range 160 ìg m−31564 ìg m−3, and amounted to 97.3 ± 3.1 ml min−1. Experimentally determined sampling rates showed deviations of 3% for acetic acid, and 321% for formic acid, in relation to theoretically derived values. The blank values were as low as 1.69 ± 0.07 ìg for formic acid and 1.21 ± 0.14 ìg for acetic acid, and detection limits lower than 0.5 ìg m−3 could be achieved, which is an improvement of 9899% compared to previously validated diffusive sampling methods. This study describes the first step of an extended validation program in which the applicability of these types of samplers for the measurement of organic acids will be validated and optimised for the environmental conditions typical for museum showcases. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000263159800038 |
Publication Date |
2008-06-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1420-2026; 1573-2967 |
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:72923 |
Serial |
7447 |
| Permanent link to this record |
| |
|
| |
| Author |
Liu, S.; Wei, M.; Sui, X.; Cheng, X.; Cool, P.; Van Tendeloo, G. |
| Title |
A scanning electron microscopy study on hollow silica microspheres: defects and influences of the synthesis composition |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of sol-gel science and technology |
Abbreviated Journal |
J Sol-Gel Sci Techn |
| Volume |
49 |
Issue |
3 |
Pages |
373-379 |
| Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Electron microscopy for materials research (EMAT) |
| Abstract |
Defects on hollow silica spheres synthesized in a tetraethylorthosilicate-octylamine-HCl-H2O system were recorded by scanning microscope. Based on the results, influences of synthesis composition on the formation of these defects are discussed. It is evidenced that products prepared with different octylamine-to-tetraethylorthosilicate ratios may have surface depressions, cracks and non-hollow microspheres. However, by changing water and acid additions, these defects could be reduced or eliminated. Generally, samples synthesized with a large octylamine addition commonly exhibit surface depressions. A small octylamine or a large water addition benefits the formation of solid silica microspheres among the product. Acid, although is not indispensable for the formation of hollow spheres, helps to eliminate or reduce depressions on the hollow shells. It is explained that the added acid gives rise to a relative localized fast hydrolysis versus condensation, facilitating an easy mobility of hydrolyzed silica species, and consequently the shell surface is smoothened. |
| Address |
|
| Corporate Author |
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Thesis |
|
| Publisher |
Kluwer |
Place of Publication |
Dordrecht |
Editor |
|
| Language |
|
Wos |
000263260100015 |
Publication Date |
2008-12-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0928-0707;1573-4846; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.575 |
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.575; 2009 IF: 1.393 |
| Call Number |
UA @ lucian @ c:irua:74962 |
Serial |
2941 |
| 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 |
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 |
|
| Language |
|
Wos |
000263319000015 |
Publication Date |
2009-01-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
| Permanent link to this record |
| |
|
| |
| Author |
Tran, M.L.; Centeno, S.P.; Hutchison, J.A.; Engelkamp, H.; Liang, D.; Van Tendeloo, G.; Sels, B.F.; Hofkens, J.; Uji-i, H. |
| Title |
Control of surface plasmon localization via self-assembly of silver nanoparticles along silver nanowires |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
| Volume |
130 |
Issue |
51 |
Pages |
17240-17241 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A simple and low-cost method to create metal−metal hybrid nanostructures possessing fairly regularly spaced hot-spots of surface plasmon resonances is proposed. The nanohybrid structure was prepared via self-assembly during a simple drop-casting procedure, using chemically synthesized silver nanowires and silver nanoparticles prepared in a single batch of a polyol process. Wide field illumination of these nanohybrids produced hot-spots with spacings of around 500 nm to 1 ìm. The intensity of the emission/scattering from the hot-spots fluctuates over time. The proposed structure can be useful for the development of molecular-sensors or as a substrate for surface enhanced Raman/fluorescence spectroscopy. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000263320600018 |
Publication Date |
2008-12-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
13.858 |
Times cited |
51 |
Open Access |
|
| Notes |
Fwo – G.0366.06; Fwo – Iap-Vi/27 |
Approved |
Most recent IF: 13.858; 2008 IF: 8.091 |
| Call Number |
UA @ lucian @ c:irua:75946 |
Serial |
498 |
| Permanent link to this record |
| |
|
| |
| Author |
Figuerola, A.; Franchini, I.R.; Fiore, A.; Mastria, R.; Falqui, A.; Bertoni, G.; Bals, S.; Van Tendeloo, G.; Kudera, S.; Cingolani, R.; Manna, L. |
| Title |
End-to-end assembly of shape-controlled nanocrystals via a nanowelding approach mediated by gold domains |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
| Volume |
21 |
Issue |
5 |
Pages |
550-554 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Welding nanocrystals for assembly: The welding of Au domains grown on the tips of shape-controlled cadmium chalcogenide colloidal nanocrystals is used as a strategy for their assembly. Iodine-induced coagulation of selectively grown Au domains leads to assemblies such as flowerlike structures based on bullet-shaped nanocrystals, linear and cross-linked chains of nanorods, and globular networks with tetrapods as building blocks. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000263371800005 |
Publication Date |
2008-11-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0935-9648; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
19.791 |
Times cited |
110 |
Open Access |
|
| Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 19.791; 2009 IF: 8.379 |
| Call Number |
UA @ lucian @ c:irua:75960 |
Serial |
1037 |
| 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 |
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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000263450300015 |
Publication Date |
2009-01-22 |
| 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 |
100 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:76318 |
Serial |
2565 |
| Permanent link to this record |
| |
|
| |
| Author |
Doenen, M.; Zhang, L.; Erni, R.; Williams, O.A.; Hardy, A.; van Bael, M.K.; Wagner, P.; Haenen, K.; Nesladek, M.; Van Tendeloo, G. |
| Title |
Diamond nucleation by carbon transport from buried nanodiamond TiO2 sol-gel composites |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
| Volume |
21 |
Issue |
6 |
Pages |
670-673 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000263492000007 |
Publication Date |
2008-12-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0935-9648;1521-4095; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
19.791 |
Times cited |
20 |
Open Access |
|
| Notes |
Fwo; Iap-P6/42; Esteem 026019 |
Approved |
Most recent IF: 19.791; 2009 IF: NA |
| Call Number |
UA @ lucian @ c:irua:76329 |
Serial |
688 |
| Permanent link to this record |
| |
|
| |
| Author |
Lamoen, D.; March, N.H. |
| Title |
Orientational disorder in some molecular solids in relation to the boson peak in glasses |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physics letters : A |
Abbreviated Journal |
Phys Lett A |
| Volume |
373 |
Issue |
7 |
Pages |
799-800 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Orientational disorder in some molecular solids is discussed in relation to the emphasis placed on transverse vibrational modes in glasses as the origin of the observed boson peak in two very recent contributions in Nature Materials. In particular, facts are here presented for (i) CH4, (ii) C60 and (iii) ethanol in their solid phases for (a) specific heat and (b) neutron scattering. The results for ethanol in particular do not fit in with the interpretation of the boson peak in terms of transverse acoustic phonons in disordered systems. Glasses will therefore have to be separated into at least two classes where the physical interpretation of the boson peak is concerned. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000263515500020 |
Publication Date |
2009-01-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0375-9601; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.772 |
Times cited |
3 |
Open Access |
|
| Notes |
Bof |
Approved |
Most recent IF: 1.772; 2009 IF: 2.009 |
| Call Number |
UA @ lucian @ c:irua:72917 |
Serial |
2516 |
| Permanent link to this record |
| |
|
| |
| Author |
Ludu, A. |
| Title |
Fiber bundle description of flow and nonlinear hydrodynamics on circles |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Journal of nonlinear mathematical physics |
Abbreviated Journal |
J Nonlinear Math Phy |
| Volume |
15 |
Issue |
|
Pages |
157-170 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We introduce a differential geometry description of the path lines, stream lines and particles contours in hydrodynamics. We present a generalized form of a Korteweg-de Vries type of equation for the exterior of a circle. Nonlinearities from the boundary conditions, surface tension and the Euler equations are taken into account, but the flow is considered inviscid and irrotational. For the circular case we describe the traveling waves shapes, solitons and the particles trajectories. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000263517200012 |
Publication Date |
2008-09-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1402-9251;1776-0852; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
0.986 |
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 0.986; 2008 IF: 0.760 |
| Call Number |
UA @ lucian @ c:irua:94603 |
Serial |
1189 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| 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 |
| Permanent link to this record |
| |
|
| |
| Author |
Shpanchenko, R.V.; Tsirlin, A.A.; Hadermann, J.; Antipov, E.V. |
| Title |
Synthesis and crystal structure of new titanyl phosphate Sr2TiO(PO4)2 |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Russian chemical bulletin |
Abbreviated Journal |
Russ Chem B+ |
| Volume |
57 |
Issue |
3 |
Pages |
552-556 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
New strontium titanyl phosphate Sr2TiO(PO4)2 (1) was synthesized and characterized by X-ray powder diffraction, electron diffraction, high-resolution electron microscopy, and band structure calculations. Titanyl phosphate 1 is isostructural with vanadyl phosphate Sr2VO(PO4)2 and has a layered structure. The titanium atoms are shifted from the centers of the TiO6 octahedra and form short (1.74 Å) titanyl bonds. The structure of 1 is an unusual example of the disordered orientation of the chains formed by TiO6 octahedra in complex titanium phosphates. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000263566900015 |
Publication Date |
2009-03-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1066-5285;1573-9171; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
0.529 |
Times cited |
2 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 0.529; 2008 IF: 0.469 |
| Call Number |
UA @ lucian @ c:irua:73712 |
Serial |
3423 |
| Permanent link to this record |
| |
|
| |
| Author |
Mao, D.; Lookman, R.; van de Weghe, H.; Vanermen, G.; de Brucker, N.; Diels, L. |
| Title |
Detailed analysis of petroleum hydrocarbon attenuation in biopiles by high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of chromatography : A |
Abbreviated Journal |
|
| Volume |
1216 |
Issue |
9 |
Pages |
1524-1527 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Enhanced bioremediation of petroleum hydrocarbons in two biopiles was quantified by high-performance liquid chromatography (HPLC) followed by comprehensive two-dimensional gas chromatography (GCXGC). The attenuation of 34 defined hydrocarbon classes was calculated by HPLCGCXGC analysis of representative biopile samples at start-up and after 18 weeks of biopile operation. In general, a-cyclic alkanes were most efficiently removed from the biopiles, followed by monoaromatic hydrocarbons. Cycloalkanes and polycyclic aromatic hydrocarbons (PAHs) were more resistant to degradation. A-cyclic biomarkers farnesane, trimethyl-C13, norpristane, pristane and phytane dropped to only about 10% of their initial concentrations. On the other hand, C29C31 hopane concentrations remained almost unaltered after 18 weeks of biopile operation, confirming their resistance to biodegradation. They are thus reliable indicators to estimate attenuation potential of petroleum hydrocarbons in biopile processed soils. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000263610500035 |
Publication Date |
2009-01-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-9673 |
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:76320 |
Serial |
7769 |
| Permanent link to this record |
| |
|
| |
| Author |
Bogaerts, A. |
| Title |
Hybrid Monte Carlo: fluid model for studying the effects of nitrogen addition to argon glow discharges |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
Spectrochim Acta B |
| Volume |
64 |
Issue |
2 |
Pages |
126-140 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
A computer model is developed for describing argon/nitrogen glow discharges. The species taken into account in the model include electrons, Ar atoms in the ground state and in the 4s metastable levels, N2 molecules in the ground state and in six different electronically excited levels, N atoms, Ar+ ions, N+, N2+, N3+ and N4+ ions. The fast electrons are simulated with a Monte Carlo model, whereas all other species are treated in a fluid model. 74 different chemical reactions are considered in the model. The calculation results include the densities of all the different plasma species, as well as information on their production and loss processes. The effect of different N2 additions, in the range between 0.1 and 10%, is investigated. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000263621300002 |
Publication Date |
2008-12-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0584-8547; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.241 |
Times cited |
49 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.241; 2009 IF: 2.719 |
| Call Number |
UA @ lucian @ c:irua:72829 |
Serial |
1525 |
| Permanent link to this record |
| |
|
| |
| Author |
Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T. |
| Title |
Continuum vs. discrete flux behaviour in large mesoscopic Bi2Sr2CaCu2O8+\delta disks |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
| Volume |
85 |
Issue |
1 |
Pages |
17008,1-17008,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Scanning Hall probe and local Hall magnetometry measurements have been used to investigate flux distributions in large mesoscopic superconducting disks with sizes that lie near the crossover between the bulk and mesoscopic vortex regimes. Results obtained by directly mapping the magnetic induction profiles of the disks at different applied fields can be quite successfully fitted to analytic models which assume a continuous distribution of flux in the sample. At low fields, however, we do observe clear signatures of the underlying discrete vortex structure and can resolve the characteristic mesoscopic compression of vortex clusters in increasing magnetic fields. Even at higher fields, where single-vortex resolution is lost, we are still able to track configurational changes in the vortex patterns, since competing vortex orders impose unmistakable signatures on “local” magnetisation curves as a function of the applied field. Our observations are in excellent agreement with molecular-dynamics numerical simulations which lead us to a natural definition of the lengthscale for the crossover between discrete and continuum behaviours in our system. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Paris |
Editor |
|
| Language |
|
Wos |
000263692500029 |
Publication Date |
2009-01-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.957 |
Times cited |
17 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.957; 2009 IF: 2.893 |
| Call Number |
UA @ lucian @ c:irua:76306 |
Serial |
495 |
| Permanent link to this record |
| |
|
| |
| Author |
Vlasov, I.I.; Barnard, A.S.; Ralchenko, V.G.; Lebedev, O.I.; Kanzyuba, M.V.; Saveliev, A.V.; Konov, V.I.; Goovaerts, E. |
| Title |
Nanodiamond photoemitters based on strong narrow-band luminescence from silicon-vacancy defects |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
| Volume |
21 |
Issue |
7 |
Pages |
808-812 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Nanostructured and organic optical and electronic materials (NANOrOPT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000263737800012 |
Publication Date |
2008-12-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0935-9648;1521-4095; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
19.791 |
Times cited |
98 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 19.791; 2009 IF: NA |
| Call Number |
UA @ lucian @ c:irua:74513 |
Serial |
2253 |
| 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 |
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 |
|
| Corporate Author |
|
Thesis |
|
| 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 |
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 |
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 |
|
| Corporate Author |
|
Thesis |
|
| 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 |
Horemans, B.; Krata, A.; Buczyńska, A.J.; Dirtu, A.C.; van Meel, K.; Van Grieken, R.; Bencs, L. |
| Title |
Major ionic species in size-segregated aerosols and associated gaseous pollutants at a coastal site on the Belgian North Sea |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of environmental monitoring |
Abbreviated Journal |
|
| Volume |
11 |
Issue |
3 |
Pages |
670-677 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The chemical composition of airborne particulate matter (PM) was studied at a coastal region near De Haan, Belgium, during a winterspring and a summer campaign in 2006. The major ionic components of size-segregated PM, i.e. NH4+, Na+, K+, Mg2+, Ca2+, Cl-, NO3-, and SO42-, and related gaseous pollutants (SO2, NO2, NH3, HNO2, and HNO3) were monitored on a daily basis. Air mass backward-trajectories aided in evaluating the origin of the diurnal pollution load. This was characterised with high levels of fine secondary inorganic aerosols (NH4+, NO3-, and non-sea-salt SO42-) for continental air masses, and sea-salts as the dominant species in coarse maritime aerosols. Seasonal variations in the level of major ionic species were explained by weather conditions and the release of dimethyl sulfide from marine regions. This species was responsible for an increased sea-salt Cl- depletion during summer (56%), causing elevated levels of HCl. Neutralisation ratios for the coarse fraction (0.60.8) suggested a depleted NH4+ level, while that for the fine fraction (1.11.3) had definitely an excess of NH4+, formed by the neutralisation of HCl. The results of factor analysis and the extent of SO2 oxidation indicated that the major ionic species originated from both local and remote sources, classifying the Belgian coastal region as a combined sourcereceptor area of air pollution. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000264098400022 |
Publication Date |
2008-12-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1464-0325; 1464-0333 |
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:74341 |
Serial |
8196 |
| Permanent link to this record |
