| Records |
| Author |
Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Groeseneken, G.; Fischetti, M.V. |
| Title |
Impact of field-induced quantum confinement in tunneling field-effect devices |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
14 |
Pages |
143503,1-143503,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Being the working principle of a tunnel field-effect transistor, band-to-band tunneling is given a rigorous quantum mechanical treatment to incorporate confinement effects, multiple electron and hole valleys, and interactions with phonons. The model reveals that the strong band bending near the gate dielectric, required to create short tunnel paths, results in quantization of the energy bands. Comparison with semiclassical models reveals a big shift in the onset of tunneling. The effective mass difference of the distinct valleys is found to reduce the subthreshold swing steepness. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos  |
000289297800074 |
Publication Date |
2011-04-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
76 |
Open Access |
|
| Notes |
; The authors acknowledge Anne Verhulst for useful discussions. William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by IMEC's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:89297 |
Serial |
1559 |
| Permanent link to this record |
| |
|
| |
| Author |
Yusupov, M.; Bultinck, E.; Depla, D.; Bogaerts, A. |
| Title |
Elucidating the asymmetric behavior of the discharge in a dual magnetron sputter deposition system |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
13 |
Pages |
131502-131502,3 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
A magnetron discharge is characterized by drifts of the charged particles guiding center, caused by the magnetic field, in contrast to unmagnetized discharges. Because of these drifts, a pronounced asymmetry of the discharge can be observed in a dual magnetron setup. In this work, it is found that the shape of the discharge in a dual magnetron configuration depends on the magnetic field configuration. In a closed configuration, strong drifts were observed in one preferential direction, whereas in a mirror configuration the deflection of the discharge was not so pronounced. Our calculations confirm experimental observations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000289153600017 |
Publication Date |
2011-04-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
4 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:87867 |
Serial |
1026 |
| Permanent link to this record |
| |
|
| |
| Author |
Yusupov, M.; Bultinck, E.; Depla, D.; Bogaerts, A. |
| Title |
Behavior of electrons in a dual-magnetron sputter deposition system : a Monte Carlo model |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
| Volume |
13 |
Issue |
|
Pages |
033018-033018,17 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
A Monte Carlo model has been developed for investigating the electron behavior in a dual-magnetron sputter deposition system. To describe the three-dimensional (3D) geometry, different reference frames, i.e. a local and a global coordinate system, were used. In this study, the influence of both closed and mirror magnetic field configurations on the plasma properties is investigated. In the case of a closed magnetic field configuration, the calculated electron trajectories show that if an electron is emitted in (or near) the center of the cathode, where the influence of the magnetic field is low, it is able to travel from one magnetron to the other. On the other hand, when an electron is created at the race track area, it is more or less trapped in the strong magnetic field and cannot easily escape to the second magnetron region. In the case of a mirror magnetic field configuration, irrespective of where the electron is emitted from the cathode, it cannot travel from one magnetron to the other because the magnetic field lines guide the electron to the substrate. Moreover, the electron density and electron impact ionization rate have been calculated and studied in detail for both configurations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000289064600001 |
Publication Date |
2011-03-15 |
| 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 |
12 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.786; 2011 IF: 4.177 |
| Call Number |
UA @ lucian @ c:irua:87544 |
Serial |
224 |
| Permanent link to this record |
| |
|
| |
| Author |
Liu, C.-Y.; Berdiyorov, G.R.; Milošević, M.V. |
| Title |
Vortex states in layered mesoscopic superconductors |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
10 |
Pages |
104524-104524,10 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Within the Ginzburg-Landau theory, we study the vortex structures in three-dimensional anisotropic mesoscopic superconductors in the presence of a uniform magnetic field. Anisotropy is included through varied Tc in different layers of the sample and leads to distinct differences in the vortex states and their free energy. Several unconventional states are found, some comprising vortex clusters or exhibiting asymmetry. In a tilted magnetic field, we found second-order transitions between different vortex states, although vortex entry is generally a first-order transition in mesoscopic samples. In multilayered samples the kinked vortex strings are formed owing to the competing interactions of vortices with Meissner currents and the weak-link boundaries. The length and deformation of vortex fragments are determined solely by the inclination and strength of applied magnetic field, and this lock-in does not depend on the degree of anisotropy between the superconducting layers. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000288998200003 |
Publication Date |
2011-03-31 |
| 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 |
22 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:89375 |
Serial |
3888 |
| Permanent link to this record |
| |
|
| |
| Author |
Vernimmen, J.; Guidotti, M.; Silvestre-Albero, J.; Jardim, E.O.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Psaro, R.; Rodríguez-Reinoso, F.; Meynen, V.; Cool, P. |
| Title |
Immersion calorimetry as a tool to evaluate the catalytic performance of titanosilicate materials in the epoxidation of cyclohexene |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Langmuir: the ACS journal of surfaces and colloids |
Abbreviated Journal |
Langmuir |
| Volume |
27 |
Issue |
7 |
Pages |
3618-3625 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
| Abstract |
Different types of titanosilicates are synthesized, structurally characterized, and subsequently catalytically tested in the liquid-phase epoxidation of cyclohexene. The performance of three types of combined zeolitic/mesoporous materials is compared with that of widely studied Ti-grafted-MCM-41 molecular sieve and the TS-1 microporous titanosilicate. The catalytic test results are correlated with the structural characteristics of the different catalysts. Moreover, for the first time, immersion calorimetry with the same substrate molecule as in the catalytic test reaction is applied as an extra means to interpret the catalytic results. A good correlation between catalytic performance and immersion calorimetry results is found. This work points out that the combination of catalytic testing and immersion calorimetry can lead to important insights into the influence of the materials structural characteristics on catalysis. Moreover, the potential of using immersion calorimetry as a screening tool for catalysts in epoxidation reactions is shown. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000288970900054 |
Publication Date |
2011-02-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0743-7463;1520-5827; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.833 |
Times cited |
19 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.833; 2011 IF: 4.186 |
| Call Number |
UA @ lucian @ c:irua:88366 |
Serial |
1557 |
| Permanent link to this record |
| |
|
| |
| Author |
Zeng, Y.I.; Menghini, M.; Li, D.Y.; Lin, S.S.; Ye, Z.Z.; Hadermann, J.; Moorkens, T.; Seo, J.W.; Locquet, J.-P.; van Haesendonck, C. |
| Title |
Unexpected optical response of single ZnO nanowires probed using controllable electrical contacts |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
| Volume |
13 |
Issue |
15 |
Pages |
6931-6935 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Relying on combined electron-beam lithography and lift-off methods Au/Ti bilayer electrical contacts were attached to individual ZnO nanowires (NWs) that were grown by a vapor phase deposition method. Reliable Schottky-type as well as ohmic contacts were obtained depending on whether or not an ion milling process was used. The response of the ZnO NWs to ultraviolet light was found to be sensitive to the type of contacts. The intrinsic electronic properties of the ZnO NWs were studied in a field-effect transistor configuration. The transfer characteristics, including gate threshold voltage, hysteresis and operational mode, were demonstrated to unexpectedly respond to visible light. The origin of this effect could be accounted for by the presence of point defects in the ZnO NWs. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000288951000019 |
Publication Date |
2011-03-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1463-9076;1463-9084; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.123 |
Times cited |
7 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.123; 2011 IF: 3.573 |
| Call Number |
UA @ lucian @ c:irua:89378 |
Serial |
3807 |
| Permanent link to this record |
| |
|
| |
| Author |
Matulis, A.; Masir, M.R.; Peeters, F.M. |
| Title |
Application of optical beams to electrons in graphene |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
11 |
Pages |
115458-115458,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous discussed. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000288896400013 |
Publication Date |
2011-03-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| Notes |
; This research was supported by the Flemish Science Foundation (Grant No. FWO-Vl), by the Belgian Science policy (IAP), and (in part) by the Lithuanian Science Council under project No. MIP-79/2010. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:89377 |
Serial |
142 |
| Permanent link to this record |
| |
|
| |
| Author |
Rouchon, V.; Duranton, M.; Burgaud, C.; Pellizzi, E.; Lavédrine, B.; Janssens, K.; de Nolf, W.; Nuyts, G.; Vanmeert, F.; Hellemans, K. |
| Title |
Room-temperature study of iron gall ink impregnated paper degradation under various oxygen and humidity conditions : time-dependent monitoring by viscosity and X-ray absorption near-edge spectrometry measurements |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
83 |
Issue |
7 |
Pages |
2589-2597 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Many western manuscripts were written using iron gall inks. These inks can damage the paper via two major mechanisms: (a) acid hydrolysis, enhanced by humidity, and (b) oxidative depolymerization provoked by the presence of oxygen and free iron(II) ions. The degradation of unsized Whatman paper impregnated with different combinations of iron sulfate, gallic acid, and gum arabic was studied at room temperature in order to assess the relative importance of each mechanism. The samples were stored in various environments including a dry and/or an oxygen-free atmosphere. The cellulose depolymerization was monitored by viscometry and related to changes in the oxidation state of iron, determined by X-ray absorption near-edge spectrometry. The results indicate that residual amounts of oxygen (less than 0.1%) promote cellulose depolymerization, whereas the level of relative humidity has no impact. The cellulose depolymerization also appears closely correlated to oxidative mechanisms. Regarding the oxidation of iron, it only occurs in the simultaneous presence of oxygen and moisture, suggesting the occurrence of rustlike oxidative mechanisms. Finally, the presence of gallic acid has a strong influence, which is only partially explained by its capacity to reduce iron(III) to iron(II). |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000288887700028 |
Publication Date |
2011-03-04 |
| 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 |
6.32 |
Times cited |
28 |
Open Access |
|
| Notes |
; This research was supported by the French Ministry of Culture within the National Program of Research (“La conservation des manuscrits: etude du vieillissement naturel de papiers impregnes d'encres ferrogalliques”). It was funded by grants from HASYLAB (experiments I-20090280 EC and II-20060245 EC) and SOLEIL (proposals 20060396 and 20080761) and was supported by the Interuniversity Attraction Poles Programme Belgian Science Policy (1UAP V1/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects nos. G.0689.06, G.0704.08 and G017909N. We are thankful to Dr. Dominique Thaudiere, Dr. Solenn Reguer, Dr. Andrea Somogyi, Dr. Karen Appel, Dr. Manuela Borchert, and Dr. Gerald Falkenberg for their assistance and help during the experiments performed at SOLEIL beamline “DIFFABS” and at HASYLAB Beam line “L” respectively. ; |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
| Call Number |
UA @ admin @ c:irua:89593 |
Serial |
5822 |
| Permanent link to this record |
| |
|
| |
| Author |
Li, B.; Peeters, F.M. |
| Title |
Tunable optical Aharonov-Bohm effect in a semiconductor quantum ring |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
11 |
Pages |
115448-115448,13 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
By applying an electric field perpendicular to a semiconductor quantum ring we show that it is possible to modify the single particle wave function between quantum dot (QD)-like and ring-like. The constraints on the geometrical parameters of the quantum ring to realize such a transition are derived. With such a perpendicular electric field we are able to tune the Aharanov-Bohm (AB) effect for both the single particle and for excitons. The tunability is in both the strength of the AB effect as well as in its periodicity. We also investigate the strain induce potential inside the self-assembled quantum ring and the effect of the strain on the AB effect. |
| 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 |
000288855200012 |
Publication Date |
2011-03-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
25 |
Open Access |
|
| Notes |
; This work was supported by the EU-NoE: SANDiE, the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC, vzw collaborative project. We are grateful to Prof. M. Tadic and Dr. Fei Ding for stimulating discussions. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:89376 |
Serial |
3744 |
| Permanent link to this record |
| |
|
| |
| Author |
Bonroy, J.; Volckaert, M.; Seuntjens, P. |
| Title |
Rapid automated measurement system for simultaneous determination of effective air-filled porosity and soil gas diffusivity |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Soil Science Society of America journal |
Abbreviated Journal |
|
| Volume |
75 |
Issue |
2 |
Pages |
408-417 |
| Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
The effective air-filled porosity and the gas diffusion coefficient are important soil parameters determining the success of soil bioremediation projects such as (bio)venting and (bio)sparging methods in combination with soil vapor extraction. We have developed a new method to sequentially measure the effective air-filled porosity and the soil gas diffusion coefficient of a soil sample. During the purging of the sample, a fast and accurate measurement of the effective air-filled porosity can be obtained. The subsequent diffusion measurement does not require a zero-O(2) concentration in the soil sample. The procedure further allows the calculation of the soil gas diffusion coefficient before an equilibrium O(2) concentration has been reached. The results are obtained by combining the data of the inlet and outlet compartment in a single equation. A stable reading is reached when the results for the inlet and outlet compartment coincide with the results from the combined equation. The analysis time is reduced by 89 to 96% compared with methods that run until an equilibrium concentration has been reached. Moreover, combining data from inlet and outlet compartments increases the accuracy of the diffusivity measurement by a factor of two compared with previous methods. |
| 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 |
000288827000009 |
Publication Date |
2012-09-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0361-5995 |
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:113062 |
Serial |
8453 |
| Permanent link to this record |
| |
|
| |
| Author |
Katti, G.; Stucchi, M.; Velenis, D.; Sorée, B.; de Meyer, K.; Dehaene, W. |
| Title |
Temperature-dependent modeling and characterization of through-silicon via capacitance |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
IEEE electron device letters |
Abbreviated Journal |
Ieee Electr Device L |
| Volume |
32 |
Issue |
4 |
Pages |
563-565 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A semianalytical model of the through-silicon via (TSV) capacitance for elevated operating temperatures is derived and verified with electrical measurements. The effect of temperature on the increase in TSV capacitance over different technology parameters is explored, and it is shown that higher oxide thickness reduces the impact of temperature rise on TSV capacitance, while with low doped substrates, which are instrumental for reducing the TSV capacitance, the sensitivity of TSV capacitance to temperature is large and cannot be ignored. |
| Address |
|
| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000288664800045 |
Publication Date |
2011-03-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0741-3106;1558-0563; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.048 |
Times cited |
27 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 3.048; 2011 IF: 2.849 |
| Call Number |
UA @ lucian @ c:irua:89402 |
Serial |
3498 |
| Permanent link to this record |
| |
|
| |
| Author |
Eckert, M.; Mortet, V.; Zhang, L.; Neyts, E.; Verbeeck, J.; Haenen, ken; Bogaerts, A. |
| Title |
Theoretical investigation of grain size tuning during prolonged bias-enhanced nucleation |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
23 |
Issue |
6 |
Pages |
1414-1423 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
In this paper, the effects of prolonged bias-enhanced nucleation (prolonged BEN) on the growth mechanisms of diamond are investigated by molecular dynamics (MD) and combined MD-Metropolis Monte Carlo (MD-MMC) simulations. First, cumulative impacts of CxHy+ and Hx+ on an a-C:H/nanodiamond composite were simulated; second, nonconsecutive impacts of the dominant ions were simulated in order to understand the observed phenomena in more detail. As stated in the existing literature, the growth of diamond structures during prolonged BEN is a process that takes place below the surface of the growing film. The investigation of the penetration behavior of CxHy+ and Hx+ species shows that the carbon-containing ions remain trapped within this amorphous phase where they dominate mechanisms like precipitation of sp3 carbon clusters. The H+ ions, however, penetrate into the crystalline phase at high bias voltages (>100 V), destroying the perfect diamond structure. The experimentally measured reduction of grain sizes at high bias voltage, reported in the literature, might thus be related to penetrating H+ ions. Furthermore, the CxHy+ ions are found to be the most efficient sputtering agents, preventing the build up of defective material. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000288291400011 |
Publication Date |
2011-02-23 |
| 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 |
9 |
Open Access |
|
| Notes |
Iwt; Fwo; Esteem 026019; Iap |
Approved |
Most recent IF: 9.466; 2011 IF: 7.286 |
| Call Number |
UA @ lucian @ c:irua:87642 |
Serial |
3605 |
| Permanent link to this record |
| |
|
| |
| Author |
Földi, P.; Szaszkó-Bogár, V.; Peeters, F.M. |
| Title |
High-temperature conductance of a two-dimensional superlattice controlled by spin-orbit interaction |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
11 |
Pages |
115313-115313,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Rashba-type spin-orbit interaction (SOI) controlled band structure of a two-dimensional superlattice allows for the modulation of the conductance of finite size devices by changing the strength of the SOI. We consider rectangular arrays and find that the temperature dependence of the conductance disappears for high temperatures, but the strength of the SOI still affects the conductance at these temperatures. The modulation effect can be seen even in the presence of strong dephasing, which can be important for practical applications. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000288242800007 |
Publication Date |
2011-03-11 |
| 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 |
8 |
Open Access |
|
| Notes |
; We thank M. G. Benedict and F. Bartha for useful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and M045596 and by the “TAMOP-4.2.1/B-09/1/KONV-2010-0005 project: Creating the Center of Excellence at the University of Szeged” supported by the EU and the European Regional Development Fund. P.F. was supported by a J. Bolyai grant of the Hungarian Academy of Sciences. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:88778 |
Serial |
1466 |
| Permanent link to this record |
| |
|
| |
| Author |
Dideykin, A.; Aleksenskiy, A.E.; Kirilenko, D.; Brunkov, P.; Goncharov, V.; Baidakova, M.; Sakseev, D.; Vul', A.Y. |
| Title |
Monolayer graphene from graphite oxide |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Diamond and related materials |
Abbreviated Journal |
Diam Relat Mater |
| Volume |
20 |
Issue |
2 |
Pages |
105-108 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Graphene, a new carbon material, is attracting presently an increasing research interest. It stems from the unique electrical and mechanical properties of graphene predicted by theory. Experimental studies of graphene are, however, severely curtailed by a lack of an appropriate technique for its preparation. Mechanical cleavage of graphite proved to be ineffective, since it yields only very small (a few microns in size) particles of monolayer graphene. The rapidly developing approach based on chemical exfoliation of graphite produces large-area coatings composed primarily of arbitrarily oriented multilayer graphene particles. We have developed a technique for preparation of monolayer graphene sheets involving liquid exfoliation of crystalline graphite, which includes synthesis of graphite oxide by deep oxidation as an intermediate stage. Electron diffraction traces, as well as the variation of diffracted intensities with local orientation of graphene sheets, AFM, and HRTEM images testify to a remarkably good monolayer structure of the graphite oxide particles obtained by our technique. These results open a way to setting up high-efficiency production of monolayer graphene sheets appropriate for electrical and optical measurements and fabrication of structures for use in the field of applications. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000288145500010 |
Publication Date |
2010-10-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0925-9635; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.561 |
Times cited |
48 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.561; 2011 IF: 1.913 |
| Call Number |
UA @ lucian @ c:irua:88791 |
Serial |
2193 |
| Permanent link to this record |
| |
|
| |
| Author |
Cantoro, M.; Klekachev, A.V.; Nourbakhsh, A.; Sorée, B.; Heyns, M.M.; de Gendt, S. |
| Title |
Long-wavelength, confined optical phonons in InAs nanowires probed by Raman spectroscopy |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
| Volume |
79 |
Issue |
4 |
Pages |
423-428 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Strongly confined nano-systems, such as one-dimensional nanowires, feature deviations in their structural, electronic and optical properties from the corresponding bulk. In this work, we investigate the behavior of long-wavelength, optical phonons in vertical arrays of InAs nanowires by Raman spectroscopy. We attribute the main changes in the spectral features to thermal anharmonicity, due to temperature effects, and rule out the contribution of quantum confinement and Fano resonances. We also observe the appearance of surface optical modes, whose details allow for a quantitative, independent estimation of the nanowire diameter. The results shed light onto the mechanisms of lineshape change in low-dimensional InAs nanostructures, and are useful to help tailoring their electronic and vibrational properties for novel functionalities. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
000288120600005 |
Publication Date |
2011-02-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1434-6028;1434-6036; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.461 |
Times cited |
10 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.461; 2011 IF: 1.534 |
| Call Number |
UA @ lucian @ c:irua:89502 |
Serial |
1841 |
| Permanent link to this record |
| |
|
| |
| Author |
Carvalho, J.C.N.; Ferreira, W.P.; Farias, G.A.; Peeters, F.M. |
| Title |
Yukawa particles confined in a channel and subject to a periodic potential : ground state and normal modes |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
9 |
Pages |
094109-094109,12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We consider a classical system of two-dimensional (2D) charged particles, interacting through a repulsive Yukawa potential exp(-r/λ)/r, and confined in a parabolic channel that limits the motion of the particles in the y direction. Along the x direction, the particles are subject to a periodic potential. The ground-state configurations and the normal-mode spectra of the system are obtained as a function of the periodicity and strength of the periodic potential (V0) and density. An interesting set of tunable ground-state configurations are found, with first- or second-order structural transitions between them. A configuration with particles aligned, perpendicular to the x direction, in each minimum of the periodic potential is obtained for V0 larger than some critical value that has a power-law dependence on the density. The phonon spectrum of different configurations was also calculated. A localization of the modes into a small frequency interval is observed for sufficiently large strength of the periodic potential, and a tunable gap in the phonon spectrum is found as a function of V0. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000288119700001 |
Publication Date |
2011-03-08 |
| 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 |
9 |
Open Access |
|
| Notes |
; This work was supported by the Brazilian agencies CNPq and FUNCAP (PRONEX-Grant), and the bilateral projects between Flanders and Brazil and the Flemish Science Foundation (FWO-VI) and CNPq. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:88779 |
Serial |
3928 |
| Permanent link to this record |
| |
|
| |
| Author |
Kirsanova, M.A.; Olenev, A.V.; Abakumov, A.M.; Bykov, M.A.; Shevelkov, A.V. |
| Title |
Extension of the clathrate family : the type X clathrate Ge79P29S18Te6 |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
| Volume |
50 |
Issue |
10 |
Pages |
2371-2374 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Now they are 10! The title compound displays a new type of crystal structure and is labeled clathrate X according to the general classification of clathrate structures. In contrast to typical clathrates, this compound has three-coordinate atoms within the framework and combines distorted 24-vertex polyhedra (see picture, green) centered around tellurium guest atoms with very irregular 10-vertex polyhedra around sulfur atoms (yellow). |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000288036300033 |
Publication Date |
2011-01-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1433-7851; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
11.994 |
Times cited |
23 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 11.994; 2011 IF: 13.455 |
| Call Number |
UA @ lucian @ c:irua:88793 |
Serial |
1158 |
| Permanent link to this record |
| |
|
| |
| Author |
Hao, Y.L.; Djotyan, A.P.; Avetisyan, A.A.; Peeters, F.M. |
| Title |
D- shallow donor near a semiconductor-metal and a semiconductor-dielectric interface |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
23 |
Issue |
11 |
Pages |
115303,1-115313,9 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The ground state energy and the extent of the wavefunction of a negatively charged donor (D − ) located near a semiconductormetal or a semiconductordielectric interface are obtained. We apply the effective mass approximation and use a variational two-electron wavefunction that takes into account the influence of all image charges that arise due to the presence of the interface, as well as the correlation between the two electrons bound to the donor. For a semiconductormetal interface, the D − binding energy is enhanced for donor positions d > 1.5aB (aB is the effective Bohr radius) due to the additional attraction of the electrons with their images. When the donor approaches the interface (i.e. d < 1.5aB) the D − binding energy drops and eventually it becomes unbound. For a semiconductordielectric (or a semiconductorvacuum) interface the D − binding energy is reduced for any donor position as compared to the bulk case and the system becomes rapidly unbound when the donor approaches the interface. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000287969200013 |
Publication Date |
2011-03-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
5 |
Open Access |
|
| Notes |
; This work was supported by the Belgian Science Policy (IAP) and the Brazilian Science Foundation CNPq. One of us (AAA) was supported by a fellowship from the Belgian Federal Science Policy Office (IAP). ; |
Approved |
Most recent IF: 2.649; 2011 IF: 2.546 |
| Call Number |
UA @ lucian @ c:irua:88828 |
Serial |
3528 |
| Permanent link to this record |
| |
|
| |
| Author |
Chaves, A.; Peeters, F.M.; Farias, G.A.; Milošević, M.V. |
| Title |
Vortex-vortex interaction in bulk superconductors : Ginzburg-Landau theory |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
5 |
Pages |
054516-054516,14 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The vortex-vortex interaction potential in bulk superconductors is calculated within the Ginzburg-Landau (GL) theory and is obtained from a numerical solution of a set of two coupled nonlinear GL differential equations for the vector potential and the superconducting order parameter, where the merger of vortices into a giant vortex is allowed. Further, the interaction potentials between a vortex and a giant vortex and between a vortex and an antivortex are obtained for both type-I and type-II superconductors. Our numerical results agree asymptotically with the analytical expressions for large intervortex separations that are available in the literature. We propose empirical expressions valid over the full interaction range, which are fitted to our numerical data for different values of the GL parameter. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000287712100009 |
Publication Date |
2011-02-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
31 |
Open Access |
|
| Notes |
; Discussions with J. S. Andrade Jr. and A. A. Moreira are gratefully acknowledged. This work was financially supported by CNPq, under Contract No. NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES, the Bilateral programme between Flanders and Brazil, the collaborative project CNPq-FWO-Vl, the Belgian Science Policy (IAP), and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:88805 |
Serial |
3899 |
| Permanent link to this record |
| |
|
| |
| Author |
Nga, T.T.N.; Peeters, F.M. |
| Title |
Influence of electron-electron interaction on the cyclotron resonance spectrum of magnetic quantum dots containing few electrons |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
7 |
Pages |
075419-075419,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The configuration interaction method is used to obtain the magneto-optical absorption spectrum of a few-electron (Ne=1,2,,5) quantum dot containing a single magnetic ion. We find that the IR spectrum (the position, the number, and the oscillator strength of the cyclotron resonance peaks) depends on the strength of the Coulomb interaction, the number of electrons, and the position of the magnetic ion. We find that the Kohn theorem is no longer valid as a consequence of the electron-spin-magnetic-ion-spin-exchange interaction. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000287584600011 |
Publication Date |
2011-02-23 |
| 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 |
8 |
Open Access |
|
| Notes |
; This work was supported by FWO-Vl (Flemish Science Foundation), the Brazilian science foundation CNPq, and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:88912 |
Serial |
1620 |
| Permanent link to this record |
| |
|
| |
| Author |
van Holsbeke, C.; de Backer, J.; Vos, W.; Verdonck, P.; van Ransbeeck, P.; Claessens, T.; Braem, M.; Vanderveken, O.; de Backer, W. |
| Title |
Anatomical and functional changes in the upper airways of sleep apnea patients due to mandibular repositioning: a large scale study |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of biomechanics |
Abbreviated Journal |
J Biomech |
| Volume |
44 |
Issue |
3 |
Pages |
442-449 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW) |
| Abstract |
The obstructive sleep apnea-hypopnea syndrome (OSAHS) is a sleep related breathing disorder. A popular treatment is the use of a mandibular repositioning appliance (MRA) which advances the mandibula during the sleep and decreases the collapsibility of the upper airway. The success rate of such a device is, however, limited and very variable within a population of patients. Previous studies using computational fluid dynamics have shown that there is a decrease in upper airway resistance in patients who improve clinically due to an MRA. In this article, correlations between patient-specific anatomical and functional parameters are studied to examine how MRA induced biomechanical changes will have an impact on the upper airway resistance. Low-dose computed tomography (CT) scans are made from 143 patients suffering from OSAHS. A baseline scan and a scan after mandibular repositioning (MR) are performed in order to study variations in parameters. It is found that MR using a simulation bite is able to induce resistance changes by changing the pharyngeal lumen. The change in minimal cross-sectional area is the best parameter to predict the change in upper airway resistance. Looking at baseline values, the ideal patients for MR induced resistance decrease seem to be women with short airways, high initial resistance and no baseline occlusion. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000287551000014 |
Publication Date |
2010-10-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-9290; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.664 |
Times cited |
23 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 2.664; 2011 IF: 2.434 |
| Call Number |
UA @ lucian @ c:irua:85305 |
Serial |
112 |
| Permanent link to this record |
| |
|
| |
| Author |
Sofo, J.O.; Suarez, A.M.; Usaj, G.; Cornaglia, P.S.; Hernández-Nieves, A.D.; Balseiro, C.A. |
| Title |
Electrical control of the chemical bonding of fluorine on graphene |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
8 |
Pages |
081411 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study the electronic structure of diluted F atoms chemisorbed on graphene using density functional theory calculations. We show that the nature of the chemical bonding of a F atom adsorbed on top of a C atom in graphene strongly depends on carrier doping. In neutral samples the F impurities induce a sp(3)-like bonding of the C atom below, generating a local distortion of the hexagonal lattice. As the graphene is electron-doped, the C atom retracts back to the graphene plane and for high doping (10(14) cm(-2)) its electronic structure corresponds to a nearly pure sp(2) configuration. We interpret this sp(3)-sp(2) doping-induced crossover in terms of a simple tight-binding model and discuss the physical consequences of this change. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000287484800005 |
Publication Date |
2011-02-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
65 |
Open Access |
|
| Notes |
; J.O.S. and A. S. acknowledge support from the Donors of the American Chemical Society Petroleum Research Fund and use of facilities at the Penn State Materials Simulation Center. G. U., P. S. C., A. D. H., and C. A. B. acknowledge financial support from PICTs 06-483 and 2008-2236 from ANPCyT and PIP 11220080101821 from CONICET, Argentina. A. D. H. acknowledges support from the Flemish Science Foundation (FWO). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:105600 |
Serial |
892 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Aert, S.; Batenburg, K.J.; Rossell, M.D.; Erni, R.; Van Tendeloo, G. |
| Title |
Three-dimensional atomic imaging of crystalline nanoparticles |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| Volume |
470 |
Issue |
7334 |
Pages |
374-377 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
| Abstract |
Determining the three-dimensional (3D) arrangement of atoms in crystalline nanoparticles is important for nanometre-scale device engineering and also for applications involving nanoparticles, such as optoelectronics or catalysis. A nanoparticles physical and chemical properties are controlled by its exact 3D morphology, structure and composition1. Electron tomography enables the recovery of the shape of a nanoparticle from a series of projection images2, 3, 4. Although atomic-resolution electron microscopy has been feasible for nearly four decades, neither electron tomography nor any other experimental technique has yet demonstrated atomic resolution in three dimensions. Here we report the 3D reconstruction of a complex crystalline nanoparticle at atomic resolution. To achieve this, we combined aberration-corrected scanning transmission electron microscopy5, 6, 7, statistical parameter estimation theory8, 9 and discrete tomography10, 11. Unlike conventional electron tomography, only two images of the targeta silver nanoparticle embedded in an aluminium matrixare sufficient for the reconstruction when combined with available knowledge about the particles crystallographic structure. Additional projections confirm the reliability of the result. The results we present help close the gap between the atomic resolution achievable in two-dimensional electron micrographs and the coarser resolution that has hitherto been obtained by conventional electron tomography. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000287409100037 |
Publication Date |
2011-02-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0028-0836;1476-4687; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
40.137 |
Times cited |
341 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: 40.137; 2011 IF: 36.280 |
| Call Number |
UA @ lucian @ c:irua:86745 |
Serial |
3644 |
| Permanent link to this record |
| |
|
| |
| Author |
Čevik, U.; Damla, N.; Van Grieken, R.; Vefa Akpinar, M. |
| Title |
Chemical composition of building materials used in Turkey |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Construction and building materials |
Abbreviated Journal |
|
| Volume |
25 |
Issue |
4 |
Pages |
1546-1552 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The main goal of this work was to determine the chemical composition of building materials used in Turkey by utilizing energy dispersive X-ray fluorescence (EDXRF) spectrometry. Gas concrete, cement, sand, bricks, roofing tiles, marble, lime and gypsum materials were selected as building materials for this research. The chemical contents and their trace concentrations of the selected samples were determined. The most abundant oxides measured were generally SiO2, Al2O3, CaO, MgO, Fe2O3, K2O and SO3 for all samples. While the main chemical component of gas concrete, cement, sand and marble samples were SiO2 and CaO, brick and roofing tile mainly consisted of SiO2 and Al2O3. CaO and SO3 were major component of lime and gypsum samples, respectively. For U and Th concentrations in the samples, activities of 226Ra and 232Th were measured by utilizing gamma spectrometry. ANOVA and Pearson correlation analyses were performed on the studied data for statistical analysis. |
| 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 |
000287379300007 |
Publication Date |
2010-09-22 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
|
| ISSN |
0950-0618 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:86448 |
Serial |
7653 |
| Permanent link to this record |
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| Author |
Navulla, A.; Tsirlin, A.A.; Abakumov, A.M.; Shpanchenko, R.V.; Zhang, H.; Dikarev, E.V. |
| Title |
Fluorinated heterometallic \beta-diketonates as volatile single-source precursors for the synthesis of low-valent mixed-metal fluorides |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
| Volume |
133 |
Issue |
4 |
Pages |
692-694 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Hexafluoroacetylacetonates that contain lead and divalent first-row transition metals, PbM(hfac)4 (M = Ni (1), Co (2), Mn (3), Fe (4), and Zn (5)), have been synthesized. Their heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating−bridging fashion. Compounds 1−5 are highly volatile and decompose below 350 °C. Fluorinated heterometallic β-diketonates have been used for the first time as volatile single-source precursors for the preparation of mixed-metal fluorides. Complex fluorides of composition Pb2MF6 have been obtained by decomposition of 1−5 in a two-zone furnace under low-pressure nitrogen flow. Lead−transition metal fluorides conform to orthorhombically distorted Aurivillius-type structure with layers of corner-sharing [MF6] octahedra separated by α-PbO-type (Pb2F2) blocks. Pb2NiF6 and Pb2CoF6 were found to exhibit magnetic ordering below 80 and 43 K, respectively. The ordering is antiferromagnetic, with a weak, uncompensated moment due to the canting of spins. The Pb2MF6 fluorides represent a new class of prospective magnetoelectric materials combining transition metals and lone-pair main-group cations. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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| Language |
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Wos |
000287295300015 |
Publication Date |
2010-12-21 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
|
| ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
13.858 |
Times cited |
28 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 13.858; 2011 IF: 9.907 |
| Call Number |
UA @ lucian @ c:irua:88820 |
Serial |
1236 |
| Permanent link to this record |
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| |
| Author |
Cao, S.; Nishida, M.; Schryvers, D. |
| Title |
Quantitative three-dimensional analysis of Ni4Ti3 precipitate morphology and distribution in polycrystalline Ni-Ti |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
59 |
Issue |
4 |
Pages |
1780-1789 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates in a Ni50.8Ti49.2 polycrystalline shape memory alloy with a heterogeneous microstructure have been investigated using a focused ion beam/scanning electron microscopy slice-and-view procedure. The mean volume, central plane diameter, thickness, aspect ratio and sphericity of the precipitates in the grain interior as well as near to the grain boundary were measured and/or calculated. The morphology of the precipitates was quantified by determining the equivalent ellipsoids with the same moments of inertia and classified according to the Zingg scheme. Also, the pair distribution functions describing the three-dimensional distributions were obtained from the coordinates of the precipitate mass centres. Based on this new data it is suggested that the existence of the heterogeneous microstructure could be due to a very small concentration gradient in the grains of the homogenized material and that the resulting multistage martensitic transformation originates in strain effects related to the size of the precipitates and scale differences of the available B2 matrix in between the precipitates. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Oxford |
Editor |
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| Language |
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Wos |
000287265100045 |
Publication Date |
2010-12-20 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.301 |
Times cited |
34 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
| Call Number |
UA @ lucian @ c:irua:85533 |
Serial |
2766 |
| Permanent link to this record |
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| Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Dik, J.; Radepont, M.; Hendriks, E.; Geldof, M.; Cotte, M. |
| Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 2 : original paint layer samples |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
83 |
Issue |
4 |
Pages |
1224-1231 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The darkening of the original yellow areas painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is a phenomenon widely observed on several paintings by Vincent van Gogh, such as the famous different versions of Sunflowers. During our previous investigations on artificially aged model samples of lead chromate, we established for the first time that darkening of chrome yellow is caused by reduction of PbCrO4 to Cr2O3·2H2O (viridian green), likely accompanied by the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide]. In the second part of this work, in order to demonstrate that this reduction phenomenon effectively takes place in real paintings, we study original paint samples from two paintings of V. van Gogh. As with the model samples, in view of the thin superficial alteration layers that are present, high lateral resolution spectroscopic methods that make use of synchrotron radiation (SR), such as microscopic X-ray absorption near edge (μ-XANES) and X-ray fluorescence spectrometry (μ-XRF) were employed. Additionally, μ-Raman and mid-FTIR analyses were carried out to completely characterize the samples. On both paint microsamples, the local presence of reduced Cr was demonstrated by means of μ-XANES point measurements. The presence of Cr(III) was revealed in specific areas, in some cases correlated to the presence of Ba(sulfate) and/or to that of aluminum silicate compounds. |
| 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 |
000287176900012 |
Publication Date |
2011-02-14 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
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| ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
84 |
Open Access |
|
| Notes |
; This research was funded by grants from ESRF (experiment EC-504) and by HASYLAB (experiments 11-20080130 EC and 11-20070157 EC) and was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0103.04, G.0689.06, and G.0704.08. The staff of the Van Gogh Museum, Amsterdam, is acknowledged for their agreeable cooperation and for the authorization to publish the images of the paintings in this article. L.M. was financially supported by the Erasmus Placement in the framework of Lifelong Learning Programme (A.Y. 2009-2010). The EU Community's FP7 Research Infrastructures program under the CHARISMA Project (Grant Agreement 228330) is also acknowledged. ; |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
| Call Number |
UA @ admin @ c:irua:88795 |
Serial |
5571 |
| Permanent link to this record |
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| Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M. |
| Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
83 |
Issue |
4 |
Pages |
1214-1223 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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| Language |
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Wos |
000287176900011 |
Publication Date |
2011-02-14 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-2700;1520-6882; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
113 |
Open Access |
|
| Notes |
Iuap; Fwo |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
| Call Number |
UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 |
Serial |
632 |
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| Author |
Peelaers, H.; Hernández-Nieves, A.D.; Leenaerts, O.; Partoens, B.; Peeters, F.M. |
| Title |
Vibrational properties of graphene fluoride and graphane |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
98 |
Issue |
5 |
Pages |
051914 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The vibrational properties of graphene fluoride and graphane are studied using ab initio calculations. We find that both sp(3) bonded derivatives of graphene have different phonon dispersion relations and phonon densities of states as expected from the different masses associated with the attached atoms of fluorine and hydrogen, respectively. These differences manifest themselves in the predicted temperature behavior of the constant-volume specific heat of both compounds. (C) 2011 American Institute of Physics. [doi:10.1063/1.3551712] |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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| Language |
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Wos |
000286988400027 |
Publication Date |
2011-02-02 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
66 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-V1), the Belgian Science Policy (IAP), and the collaborative project FWO-MINCyT (Contract No. FW /08/01). A.D.H.-N. is also supported by ANPCyT (under Grant No. PICT2008-2236) ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
| Call Number |
UA @ lucian @ c:irua:105604 |
Serial |
3844 |
| Permanent link to this record |
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| Author |
Ma, J.; Duong, T.H.; Smits, M.; Verstraete, W.; Carballa, M. |
| Title |
Enhanced biomethanation of kitchen waste by different pre-treatments |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Bioresource technology |
Abbreviated Journal |
|
| Volume |
102 |
Issue |
2 |
Pages |
592-599 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
Five different pre-treatments were investigated to enhance the solubilisation and anaerobic biodegradability of kitchen waste (
KW) in thermophilic batch and continuous tests. In the batch solubilisation tests, the highest and the lowest solubilisation efficiency were achieved with the thermo-acid and the pressuredepressure pre-treatments, respectively. However, in the batch biodegradability tests, the highest cumulative biogas production was obtained with the pressuredepressure method. In the continuous tests, the best performance in terms of an acceptable biogas production efficiency of 60% and stable in-reactor CODs and VFA concentrations corresponded to the pressuredepressure reactor, followed by freezethaw, acid, thermo-acid, thermo and control. The maximum OLR (5 g COD L−1 d−1) applied in the pressuredepressure and freezethaw reactors almost doubled the control reactor. From the overall analysis, the freezethaw pre-treatment was the most profitable process with a net potential profit of around 11.5 ton−1 KW. |
| 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 |
000286782700022 |
Publication Date |
2010-08-12 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
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Edition |
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| ISSN |
0960-8524 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
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| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:85249 |
Serial |
7910 |
| Permanent link to this record |
