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Author |
Lorenz, H.; Zhao, Q.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Kloetzer, B.; Rameshan, C.; Pfaller, K. |
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Title |
Origin of different deactivation of Pd/SnO2 and Pd/GeO2 catalysts in methanol dehydrogenation and reforming: a comparative study |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
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Volume |
381 |
Issue |
1/2 |
Pages |
242-252 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/ reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473 K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metalsupport interaction after reduction at 573673 K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573 K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metalsupport interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic -Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed. |
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Place of Publication |
Amsterdam |
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Wos |
000279100700029 |
Publication Date |
2010-04-26 |
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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 |
0926-860X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.339 |
Times cited |
14 |
Open Access |
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Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
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Call Number |
UA @ lucian @ c:irua:83927 |
Serial |
2522 |
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Author |
Zhao, Q.; Lorenz, H.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Rameshan, C.; Klötzer, B.; Konzett, J.; Penner, S. |
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Title |
Catalytic characterization of pure SnO2 and GeO2 in methanol steam reforming |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
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Volume |
375 |
Issue |
2 |
Pages |
188-195 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Structural changes of a variety of different SnO, SnO2 and GeO2 catalysts upon reduction in hydrogen were correlated with associated catalytic changes in methanol steam reforming. Studied systems include SnO, SnO2 and GeO2 thin film model catalysts prepared by vapour phase deposition and growth on polycrystalline NaCl surfaces and, for comparison, the corresponding pure oxide powder catalysts. Reduction of both the SnO2 thin film and powder at around 673 K in 1 bar hydrogen leads to a substantial reduction of the bulk structure and yields a mixture of SnO2 and metallic β-Sn. On the powder catalyst this transformation is fully reversible upon oxidation in 1 bar O2 at 673 K. Strongly reduced thin films, however, can only be re-transformed to SnO2 if the reduction temperature did not exceed 573 K. For GeO2, the situation is more complex due to its polymorphism. Whereas the tetragonal phase is structurally stable during reduction, oxidation or catalytic reaction, a small part of the hexagonal phase is always transformed into the tetragonal at 673 K independent of the gas phase used. SnO2 is highly active and CO2 selective in methanol steam reforming, but the initial high activity drops considerably upon reduction between 373 and 573 K and almost complete catalyst deactivation is observed after reduction at 673 K, which is associated with the parallel formation of β-Sn. In close correlation to the structural results, the catalytic activity and selectivity can be restored upon an oxidative catalyst regeneration at 673 K. Tetragonal GeO2 exhibits only a small activity and no pronounced selectivity to either CO or CO2, at least after reduction. In its fully oxidized state release of surface/lattice oxygen results in a non-catalytic formation of CO2 by oxidation of CO originating from catalytic dehydrogenation. |
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Place of Publication |
Amsterdam |
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Wos |
000275580600002 |
Publication Date |
2010-01-15 |
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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 |
0926-860X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.339 |
Times cited |
20 |
Open Access |
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Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
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Call Number |
UA @ lucian @ c:irua:81741 |
Serial |
292 |
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Author |
Lorenz, H.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Klötzer, B.; Rameshan, C.; Pfaller, K.; Penner, S. |
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Title |
Pd-In2O3 interaction due to reduction in hydrogen: consequences for methanol steam reforming |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
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Volume |
374 |
Issue |
1/2 |
Pages |
180-188 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Two different Pd/In2O3 samples including a thin film model catalyst with well-defined Pd particles grown on NaCl(0 0 1) supports and a powder catalyst prepared by an impregnation technique are examined by electron microscopy, X-ray diffraction and catalytic measurements in methanol steam reforming in order to correlate the formation of different oxide-supported bimetallic PdIn phases with catalytic activity and selectivity. A PdIn shell around the Pd particles is observed on the thin film catalyst after embedding the Pd particles in In2O3 at 300 K, likely because alloying to PdIn and oxidation to In2O3 are competing processes. Increased PdIn bimetallic formation is observed up to 573 K reduction temperature until at 623 K the film stability limit in hydrogen is reached. Oxidative treatments at 573 K lead to decomposition of PdIn and to the formation of an In2O3 shell covering the Pd particles, which irreversibly changes the activity and selectivity pattern to clean In2O3. PdIn and Pd2In3 phases are obtained on the powder catalyst after reduction at 573 K and 673 K, respectively. Only CO2-selective methanol steam reforming is observed in the reduction temperature range between 473 K and 573 K. After reduction at 673 K encapsulation of the bimetallic particles by crystalline In2O3 suppresses CO2 formation and only activity and selectivity of clean In2O3 are measured. |
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Corporate Author |
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Thesis |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000274869900023 |
Publication Date |
2009-12-18 |
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Series Editor |
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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 |
0926-860X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.339 |
Times cited |
55 |
Open Access |
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Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
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Call Number |
UA @ lucian @ c:irua:81801 |
Serial |
3553 |
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Author |
Odin, G.P.; Vanmeert, F.; Farges, F.; Gand, G.; Janssens, K.; Romero-Sarmiento, M.-F.; Steyer, J.S.; Vantelon, D.; Rouchon, V. |
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Title |
Alteration of fossil-bearing shale (Autun, France; Permian), part II : monitoring artificial and natural ageing by combined use of S and Ca K-edge XANES analysis, Rock-Eval pyrolysis and FTIR analysis |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Annales de paléontologie |
Abbreviated Journal |
Ann Paleontol |
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Volume |
101 |
Issue |
3 |
Pages |
225-239 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Fossil-bearing shale specimens that include sulfides in their compositions are chemically reactive and sometimes also mechanically fragile. This decay is often related to iron sulfate efflorescence resulting from the oxidation of sulfide compounds. The processes underlying these degradations are poorly known, thus impeding the elaboration of curative or preventive treatments. The present contribution aims to identify the origin of museum specimen alterations. It focuses on the Flouest collection housed at the Museum National d'Histoire Naturelle (MNHN, Paris, France) and originating from the Autun Basin (Saone-et-Loire, France, Permian). To evaluate the alteration of MNHN specimens, it appeared necessary to compare their composition with that of unaltered shale so as to identify chemical changes occurring during ageing. Therefore, new material was collected in the Autun Basin, among others on the locality of Muse that corresponds to the same lithostratigraphic unit as that of the MNHN specimens. This material was, if necessary, artificially aged. The first part of this work, presented elsewhere, deals with the use of Xray diffraction and Mossbauer spectroscopy for characterizing iron reactivity and speciation. It leads to the conclusion that the reactivity of iron in the shale matrix was limited and could not account for the large efflorescence of iron (II) sulfate occurring nearby the fossil. The second part presented here focuses on the use of S K-edge X-ray Absorption Near Edge Structure (XANES) spectroscopy for characterizing sulfur speciation and reactivity. Measurements were performed on the shale matrix and on thin layers of maceral found in the proximity of damaged areas. As sulfur may be found in association with calcium or organic matter, complementary techniques were implemented, such as FTIR spectroscopy, Rock-Eval pyrolysis (characterization of organic matter content) and Ca K-edge XANES (analysis of calcium speciation) spectroscopy. It was shown that sulfur is mainly related to thioether, sulfoxide, iron sulfide, and sulfates whereas calcium is mainly bound to carboxylate, carbonate and/or sulfate groups. FTIR analysis of the macerals confirmed the presence of vitrinite on damaged MNHN specimens. The low oxygen content of new shale samples determined by Rock-Eval pyrolysis indicates that the organic matter is well preserved, despite the fact that samples come from outcrop surface. In the newly collected material, sulfur is mainly related to organic sulfides (thioether) with a minor occurrence of iron sulfide. In the shale fraction of damaged MNHN specimens, sulfur is mostly oxidized into a mixture of iron and calcium sulfate. However, in the vitrinite layers of the same specimens, a large proportion of sulfur corresponds to organic sulfides. Also the oxidation of sulfur does not occur homogeneously but preferentially in the shale fraction, probably because this latter is porous whereas vitrinite is not. Artificial ageing of new shale material showed that the oxidation of organic sulfides could be reproduced at 90 degrees C, 80% of relative humidity. However, the obtained efflorescence almost exclusively corresponds to calcium sulfate whereas iron (II) sulfates are mostly observed on MNHN specimens. The new material collected on site is probably to be questioned, and future studies will have to select new samples with fossil remains. This will be the object of the third part of this work. (C) 2015 Elsevier Masson SAS. All rights reserved. |
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Wos |
000363821700009 |
Publication Date |
2015-05-09 |
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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 |
0753-3969 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.113 |
Times cited |
6 |
Open Access |
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Notes |
; This work was conducted within a PhD work that was supported by a doctoral school grant of the Museum national d'Histoire naturelle, Paris, France. We acknowledge SOLEIL for provision of synchrotron radiation facilities (Proposals ID “20130462” and “20110189”) and we would like to thank Nicolas Trcera, Pierre Lagarde and Anne Marie Flanck for assistance in using beamline LUCIA. ; |
Approved |
Most recent IF: 1.113; 2015 IF: 0.970 |
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Call Number |
UA @ admin @ c:irua:129523 |
Serial |
5462 |
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Author |
Odin, G.P.; Vanmeert, F.; Janssens, K.; Lelièvre, H.; Mertz, J.-D.; Rouchon, V. |
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Title |
Accelerated ageing of shales of palaeontological interest : impact of temperature conditions |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Annales de paléontologie |
Abbreviated Journal |
Ann Paleontol |
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Volume |
100 |
Issue |
2 |
Pages |
137-149 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The palaeontological collections of the Muséum national dHistoire naturelle (MNHN, Paris, France) and the Muséum dHistoire naturelle dAutun (MHNA, Autun, France) include many fossil specimens originating from the argillaceous shales of the Autun basin (Saône-et-Loire, France). These fossils are preserved within sedimentary rocks containing unstable sulphide compounds, such as pyrite, which may deteriorate in contact with water and oxygen. This alteration provokes crystalline efflorescence and cracks, thus compromising the preservations of the fossils. This work constitutes the first step of a project that aims to understand the mechanisms of alteration of these materials in order to define conservation guidelines for palaeontological collections. For this purpose, eight damaged specimens originating from the Permian Autun basin (Saône-et-Loire, France) were selected and analyzed by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy coupled to energy dispersive X-ray spectrometry (SEM/EDS) and X-ray absorption spectroscopy at the threshold of the sulphur Kα-edge (XANES). This methodology enabled the characterization of the matrices composition and the chemical nature of the alterations. Subsequently, we have sought to reproduce by artificial ageing the alteration phenomena encountered in the collections. New shale samples were collected on seven outcrops of the same Autun basin. They were analyzed and subjected to artificial ageing at 50% relative humidity (RH) and at temperatures ranging between 40 °C and 90 °C. Our work shows that damaged specimens and newly collected shale have a similar mineralogical composition. Yet the crystalline efflorescence material formed on the surface of damaged specimens belongs to the iron sulphate group whereas gypsum predominates on artificially aged shale samples. Reproducing the alterations observed on specimens by artificial ageing remains therefore problematic. Additionally, it appears that the temperature of ageing controls the nature of the damage: at 40 °C, many samples are mechanically damaged whereas no or minor crystalline efflorescence occurs. At 90 °C, it is the opposite tendency that is observed. Finally, mechanical damages do not seem to be correlated with the development of the efflorescence: samples with efflorescent crystals generally do not show clearly visible cracks; those that seem most fragmented do not show any visible efflorescence. |
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Wos |
000338607500006 |
Publication Date |
2014-01-24 |
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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 |
0753-3969 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.113 |
Times cited |
5 |
Open Access |
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Notes |
; This work is part of a PhD that is funded by the Museum national d'Histoire naturelle, Paris, France and was additionally supported via the S2-ART project (SDD programme of BELSPO, Brussels). The research was realized in partnership with the Palaeontological Collection Management Unit, Collection Department and with the Centre de Recherche sur la Paleodiversite et les Paleoenvironnements (CR2P, CNRS, UMR7207) of the Museum national d'Histoire naturelle, Paris, France. We are grateful to our colleagues MM. Jean Dejax and Dominique Chabard who provided palaeontological specimens and gave us access to shale deposits and Mrs Marie-Madeleine Blanc-Valleron who was of great help for the interpretation of the XRD data. ; |
Approved |
Most recent IF: 1.113; 2014 IF: 0.970 |
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Call Number |
UA @ admin @ c:irua:116594 |
Serial |
5456 |
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Author |
Fret, J.; Roef, L.; Diels, L.; Tavernier, S.; Vyverman, W.; Michiels, M. |
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Title |
Combining medium recirculation with alternating the microalga production strain : a laboratory and pilot scale cultivation test |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Algal Research-Biomass Biofuels And Bioproducts |
Abbreviated Journal |
Algal Res |
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Volume |
46 |
Issue |
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Pages |
101763 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS) |
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Abstract |
Reuse of growth medium after biomass harvesting is a cost-saving approach to improve the economic feasibility of algae mass cultivation. Algal exudates, cell debris and varying amounts of residual nutrients, impose challenges to the recycling of spent medium. In this study, the potential of combining reused medium from different algae species for growing monocultures of other algal strains was evaluated by making use of three successive cultivation setups with increasing volume; 400 mL in turbidostat mode, 2.6 L and 220 L in semi-continuous mode. Cultivation on replenished medium derived from Nannochloropsis sp. and Tisochrysis lutea, had no adverse effect on the productivity of either of the strains, regardless of whether they were grown in their own recycled medium or that of the other alga. Microfiltration of the reused medium proved to be sufficient to avoid cross-contamination. Moreover, a substantial average reduction in water footprint (77%) and nutrient cost (68% or 9 (sic).kg(-1) dry biomass) was achieved. Extension and validation of the medium recycling approach to other economically interesting algae species can contribute to improving the economic feasibility of large scale microalgae production systems. |
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Wos |
000512364900013 |
Publication Date |
2020-01-02 |
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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 |
2211-9264 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.1 |
Times cited |
4 |
Open Access |
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Notes |
; This work was financially supported by the Agency for Innovation by Science and Technology, Flanders (IWT Baekeland mandatory Jorien Fret, project no. 100678). We thank Kayawe Valentine Mubiana from the Systemic Physiological and Ecotoxicological Research group, University of Antwerp, for the assistance in the analysis of the trace elements. ; |
Approved |
Most recent IF: 5.1; 2020 IF: 3.994 |
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Call Number |
UA @ admin @ c:irua:167742 |
Serial |
6471 |
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Author |
Chekol Zewdie, M.; Van Passel, S.; Cools, J.; Tenessa, D.B.; Ayele, Z.A.; Tsegaye, E.A.; Minale, A.S.; Nyssen, J. |
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Title |
Direct and indirect effect of irrigation water availability on crop revenue in northwest Ethiopia : a structural equation model |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Agricultural Water Management |
Abbreviated Journal |
Agr Water Manage |
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Volume |
220 |
Issue |
220 |
Pages |
27-35 |
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Keywords |
A1 Journal article; Economics; Engineering Management (ENM) |
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Abstract |
Development of a clear understanding of the relationship between the availability of dam-driven irrigation water and crop revenue is important in poverty reduction and food security process. As a result, large research efforts are devoted to understanding the relationship between the availability of irrigation water and crop revenue. However, earlier studies do have several limitations. For example, without considering its indirect effect, prior studies focused solely on the direct effect of availability of irrigation water on crop revue. In this study, using a structural equation model analysis, the direct and indirect effect of availability of dam-driven irrigation water on crop revenue is decomposed and quantified specifically for the Koga irrigation scheme, located in the Mecha district of Amhara region in Ethiopia. A primary data set was collected from a randomly selected sample of 450 households in the Koga irrigation scheme. More than half of the households (254) are supported by the Koga Dam irrigation water during the dry season, and the other 196 households depended only on rainfall. The results of the study showed that, in addition to its direct effect, the availability of irrigation water indirectly affected crop revenue through receptivity of the farmers to use modern farm inputs. Around 27 percent of the total effect of dam-driven irrigation water on crop revenue was mediated by farmers’ receptivity to use yield-enhancing modern farm inputs. The results of this study suggested that the availability of irrigation water is essential to improve both crop revenue and receptivity of the farmers to use modern farm inputs. This finding also drives a strategic framework that the receptivity of the farmers to use modern farm inputs is crucial for utilizing the positive effects of irrigation water availability on crop revenue. |
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Wos |
000470941300003 |
Publication Date |
2019-04-25 |
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Series Editor |
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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 |
0378-3774 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
2.848 |
Times cited |
1 |
Open Access |
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Notes |
; The authors would like to thank Bahir Dar University – Institutional University Cooperation (BDU-IUC) VLIR_UOS project for providing us enough funds for the completion of this study. Special gratitude is given to Abrehet Kahassay and Kassahun Birhanu for helping us to map the study area; and to the data collectors (Hilemichael Fentahun, Etsehewot Birara, and Tsegachewu Degu) for their commitment. The authors gratefully acknowledge the Koga Irrigation Scheme office managers, Tewachewu Abebe, and his colleagues for their support during the data collection. The authors also acknowledge the farmers (respondents) for their willingness to spend time responding honestly to questions. ; |
Approved |
Most recent IF: 2.848 |
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Call Number |
UA @ admin @ c:irua:159246 |
Serial |
6182 |
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Author |
Annys, S.; Van Passel, S.; Dessein, J.; Adgo, E.; Nyssen, J. |
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Title |
From fast-track implementation to livelihood deterioration: The dam-based Ribb Irrigation and Drainage Project in Northwest Ethiopia |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
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Volume |
184 |
Issue |
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Pages |
102909-102913 |
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Keywords |
A1 Journal article; Engineering Management (ENM) |
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Abstract |
The 21st century revival of large-scale water resources development projects makes it important to keep assessing their impacts – preferably from an interdisciplinary perspective – in order to not repeat past mistakes and explore whether they could improve livelihood conditions for rural communities. In this study, costs and benefits of the World Bank-funded Ribb Irrigation and Drainage Project (RIDP) were investigated using a unique systems approach. The impact for farmers with different initial farming systems (rainfed – residual moisture – irrigated) was studied using field observations, document analyses, remote sensing, agronomic data and semi-structured interviews (n = 165). Data on project-induced changes to land and water availability, cropping patterns, farming systems and farm-level economics were collected. The results show that dam and dyke construction has reduced flooding, which has resulted in declining rice productivity ( – 42%) and concomitant shifts to lower value cropping systems. Results also reveal that the land redistribution has caused widespread livelihood deterioration as households had to give up 25% of their farmland and the communal grazing land was fully converted into farmland. Due to top-down implementation, nontransparent communication, delayed construction and lagging financial compensation, social resistance has appeared in the command area, impeding the construction works. In addition to these problems, if no rapid change to higher value crops can be realized, 20.5% of the farmers (those who already irrigate) will experience a loss of livelihood, 64.1% of the farmers (those with rainfed and residual moisture cultivation) will be on the verge of livelihood deterioration and only 13.5% of the farmers (those with solely rainfed cultivation) will enjoy RIDP-induced improved livelihoods. The fate of this project stresses the importance of investigating initial farming systems, exploring worthy project alternatives, improving participation, communication and benefit-sharing and strengthening the institutional capacity of implementing authorities. |
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Wos |
000564756600013 |
Publication Date |
2020-08-08 |
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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 |
0308-521x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.6 |
Times cited |
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Open Access |
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| |
Notes |
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Approved |
Most recent IF: 6.6; 2020 IF: 2.571 |
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Call Number |
UA @ admin @ c:irua:172030 |
Serial |
6927 |
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| Permanent link to this record |
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Author |
Moretti, M.; De Boni, A.; Roma, R.; Fracchiolla, M.; Van Passel, S. |
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Title |
Integrated assessment of agro-ecological systems : the case study of the “Alta Murgia” National park in Italy |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
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| |
Volume |
144 |
Issue |
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Pages |
144-155 |
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Keywords |
A1 Journal article; Engineering Management (ENM) |
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Abstract |
Several indicators and methods are already applied for sustainability assessment in agriculture. The links between sustainability indicators, agricultural management and policies are not well explained. The aim of this study is to combine biophysical and monetary sustainability assessment tools to support agriculture policy decision-making. Three methodological steps are considered: i) the environmental impacts of farms are assessed using terrestrial acidification, freshwater eutrophication, soil and freshwater ecotoxicity as well as natural land transformation; ii) the most relevant indicators of agriculture damages on ecosystems quality are aggregated into an index; iii) the farms' index scores are integrated with farm assets, land and labor, into the Sustainable Value approach (SVA), as indicator of natural resources used by farms. As a case study, the methodology was applied to arable farms with and without animal husbandry of the “Alta Murgia” National Park. The crop farms, in our sample, have a higher sustainable value using their economic and environmental resources. Mixed farms need to improve their resources use efficiency. Although crop farms have lower land-use efficiency compared to mixed farms, our results suggest supporting, by means of policy options, the specialized crop farms that, on average, perform better in terms of ecosystems quality preservation. Finally, we find that Life Cycle Assessment (LCA) to soundly measure the environmental impacts clearly enriches the SVA. (C) 2016 Elsevier Ltd. All rights reserved. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Wos |
000373553100014 |
Publication Date |
2016-02-27 |
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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 |
0308-521x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.571 |
Times cited |
6 |
Open Access |
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| |
Notes |
; We would like to thank the editor and the anonymous referees for their helpful suggestions and insightful comments that have significantly improved the paper. The authors want to thank the “Alta Murgia” Park Authority for the support in this study and all farmers that collaborated with the authors providing data. Moreover, the authors want to thank Dr. Sylvestre Njakou Djomo for the useful discussion and suggestion to build the LCA model. ; |
Approved |
Most recent IF: 2.571 |
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| |
Call Number |
UA @ admin @ c:irua:133254 |
Serial |
6218 |
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| Permanent link to this record |
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Author |
Pacini, G.C.; Merante, P.; Lazzerini, G.; Van Passel, S. |
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Title |
Increasing the cost-effectiveness of EU agri-environment policy measures through evaluation of farm and field-level environmental and economic performance |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
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| |
Volume |
136 |
Issue |
|
Pages |
70-78 |
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Keywords |
A1 Journal article; Economics; Engineering Management (ENM) |
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Abstract |
A lot of attention in the debate on the 2014-2020 programming period of the EU CAP and rural development policy revolves around the policy's contribution to enhancing resource use efficiency, decreasing environmental impact, restoring ecosystems and how to ensure more efficient and effective agrienvironmental measures (AEMs). Nevertheless, studies that simultaneously address multiple measures with multiple environmental objectives and targets are underrepresented in the scientific literature. The objectives of the present article are (i) to present an integrated tool-kit for AEM design resulting from the combination of farm modelling with the Sustainable Value Approach (SVA), and (ii) to evaluate the potential of the tool-kit to support AEM design through an application to estimate cost-effective organic agriculture payments for the dairy sector in Mugello, northern Tuscany. Sustainability assessment of organic and conventional farming systems (OFS and CFS, respectively.) under the 2007-2013 EU CAP support schemes and a no EU support scenario show better OFS performances regarding nitrogen leaching (-52% and -47% under the current CAP and the no EU support scenarios, respectively), soil erosion (-24% and -34%), potential pesticide risks (-100%), biodiversity (+13% and +30%). Income foregone for the production of environmental benefits from organic agriculture under a no EU support scenario is equal to 210 Euro/ha. Sustainable value calculations combined with modelling results indicate soil erosion and nitrogen leaching as the environmental processes to be addressed with specific policy measures to further increase the efficiency of organic farming. A new organic agriculture support scheme designed based on such indications further increases the OFS SV and almost closes the GAP with a benchmark farm of the area, featured with ideal performances in terms of environmental and economic indicators. The payment scheme we designed with the support of the integrated tool-kit shows to be more cost-effective and efficient of current AEMs. (C) 2015 Elsevier Ltd. All rights reserved. |
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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 |
000354503000007 |
Publication Date |
2015-03-18 |
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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 |
0308-521x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.571 |
Times cited |
12 |
Open Access |
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Notes |
; We wish to thank all participants to the SVAPPAS project for their inspiring contributions and challenging debates. We are furthermore grateful to the financial support from the 6th Framework Programme of the EU (project code: SSPECT – 2006 – DG AGRI). The authors are most grateful to technicians Giovanna Casella and Roberto Vivoli (University of Florence) for their technical contribution. ; |
Approved |
Most recent IF: 2.571; 2015 IF: 2.906 |
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Call Number |
UA @ admin @ c:irua:127537 |
Serial |
6216 |
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| Permanent link to this record |
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Author |
Merante, P.; Van Passel, S.; Pacini, C. |
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Title |
Using agro-environmental models to design a sustainable benchmark for the sustainable value method |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
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| |
Volume |
136 |
Issue |
|
Pages |
1-13 |
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Keywords |
A1 Journal article; Economics; Engineering Management (ENM) |
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Abstract |
Farms contribute heavily to overall sustainability. To date, various frameworks, approaches, methods and indicators have been developed to appraise how much corporations (firms, farms) contribute to sustainability. Among these, the Sustainable Value (SV) method helps to determine by which economic entity resources should be used in order to achieve the highest contributions to sustainability, by comparing company's efficiency of capital use against the efficiency of a benchmark. In this work we argue that the SV benchmark does not include certain crucial environmental concepts, such as the carrying capacity of an ecosystem or the multiple vital functions provided by ecosystem services. Thus, it is not a suitable reference for companies to evaluate their contribution to sustainability. As an alternative benchmark to standard SV applications, we propose a farm whose resource use productivity is correlated to the fulfilment of pre-determined environmental constraints: the Environmentally Sustainable Farm (ESF). To design this farm, we created an agro-environmental farm modelling framework that includes: (i) methods and approaches to assess indicators concerning specific environmental issues; (ii) an integrated ecological-economic model based on linear programming. This farm modelling framework is employed to determine both the environmental performance and the economic returns of two farming systems, conventional (CFS) and organic (OFS), which are compared using the Sustainable Value approach. Despite the fact that the OFS environmentally outperforms the CFS, none of them reaches the sustainable performances achieved by the ESF, both performing a negative Sustainable Value. The environmental constraints forced the ESF towards management choices that, although decreasing the economic performance, increase its environmental sustainability behaviour. Hence, the ESF is a viable benchmark that can be used to evaluate llllfarms' environmental sustainability. (C) 2015 Elsevier Ltd. All rights reserved. |
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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 |
000354503000001 |
Publication Date |
2015-02-25 |
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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 |
0308-521x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.571 |
Times cited |
6 |
Open Access |
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| |
Notes |
; We wish to thank all participants to the SVAPPAS project for their inspiring contributions and challenging debates. Furthermore, we are grateful to the financial support from the 6th Framework Programme of the EU (project code: SSPECT – 2006 – DG AGRI). The authors thank the technicians Giovanna Casella and Roberto Vivoli (University of Florence) for their technical contribution. ; |
Approved |
Most recent IF: 2.571; 2015 IF: 2.906 |
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Call Number |
UA @ admin @ c:irua:127536 |
Serial |
6275 |
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| Permanent link to this record |
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Author |
Meul, M.; Van Middelaar, C.E.; de Boer, I.J.M.; Van Passel, S.; Fremaut, D.; Haesaert, G. |
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Title |
Potential of life cycle assessment to support environmental decision making at commercial dairy farms |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
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Volume |
131 |
Issue |
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Pages |
105-115 |
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Keywords |
A1 Journal article; Engineering Management (ENM) |
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Abstract |
In this paper, we evaluate the potential of life cycle assessment (LCA) to support environmental decision making at commercial dairy farms. To achieve this, we follow a four-step method that allows converting environmental assessment results using LCA into case-specific advice for farmers. This is illustrated in a case-study involving 20 specialized Flemish dairy farms. Calculated LCA indicators are normalized into scores between 0 and 100, whereby a score of 100 is assumed optimal, to allow for a mutual comparison of indicators for different environmental impact categories. Next, major farm and management characteristics affecting environmental performance are identified using multiple regression and correlation analyses. Finally, comparing specific farm and management characteristics with those of best performing farms identifies farm-specific optimization strategies. We conclude that this approach complies with most of the identified critical success factors for the successful implementation of LCA as a decision support system for farmers. Key aspects herein are (i) the flexibility and accessibility of the model, (ii) the use of readily available farm data, (iii) farm advisors being intended model users, (iv) the identification of key farm and management characteristics affecting environmental performance and (v) the organization of discussion sessions involving farmers and farm advisors. However, attention should be paid (i) to provide sufficient training and guidance for farm advisors on the use of the applied LCA model and the interpretation of results, (ii) to evaluate the correctness of the used data and (iii) to keep the model up-to-date according to new scientific insights and knowledge concerning LCA methodology. (C) 2014 Elsevier Ltd. All rights reserved. |
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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 |
000343955300011 |
Publication Date |
2014-09-15 |
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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 |
0308-521x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.571 |
Times cited |
25 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.571; 2014 IF: 2.906 |
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Call Number |
UA @ admin @ c:irua:127540 |
Serial |
6238 |
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Author |
van Winsen, F.; de Mey, Y.; Lauwers, L.; Van Passel, S.; Vancauteren, M.; Wauters, E. |
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Title |
Cognitive mapping : a method to elucidate and present farmers' risk perception |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
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Volume |
122 |
Issue |
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Pages |
42-52 |
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Keywords |
A1 Journal article |
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Abstract |
Assumptions on the perceptions of risks, made in agricultural economics literature, are recognized to be over-simplistic. For example most studies assume that risks are independent and static, while in reality most risks are interlinked and dynamic. We propose an alternative method to identify and present risk perception, closer to the actual comprehension of risk by farmers. Grounded theory is used to investigate the perceptions of risk by farmers while avoiding prior assumptions. Main findings are: (i) farmers have difficulty to rank or score probability and impact of risks in a (semi)quantitative manner; (ii) farmers attach different meanings to risk, when the focus shifts between, uncertain event, probability or value at stake and; (iii) farmers perceive risks as being interrelated. Based on these findings, we propose that farmers' risk perception can be best understood as a network of interrelated notions of uncertain events, their effects and uncertain outcomes. Furthermore, cognitive mapping is suggested to elucidate and present these networks. We test cognitive mapping, exploring dairy farmers' risk perception, and demonstrate the appropriateness of this methodology for capturing the complexity and context of perceived risk. Advantages are: (i) the qualitative approach, (ii) the focus on interrelations and context, (iii) the applicability at farm level, (iv) the farmer-driven rather than researcher-driven perspective, and (v) the elucidation of the polyvalent use of the risk concept. Cognitive maps can be used as a communication tool, a risk management tool, and a tool to stimulate bi-directional learning amongst farmers, policy makers, researchers and extension agents. (C) 2013 Elsevier Ltd. All rights reserved. |
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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 |
000326910500005 |
Publication Date |
2013-09-12 |
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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 |
0308-521x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.571 |
Times cited |
27 |
Open Access |
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Notes |
; We would like to acknowledge the Agency for Innovation by Science and Technology of the Flemish Government (IWT) for funding this research. Furthermore we would like to thank the anonymous reviewers for their valuable input. ; |
Approved |
Most recent IF: 2.571; 2013 IF: 2.453 |
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Call Number |
UA @ admin @ c:irua:112765 |
Serial |
6168 |
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Author |
Reynaert, S.; Vienne, A.; de Boeck, H.J.; D'Hose, T.; Janssens, I.; Nijs, I.; Portillo-Estrada, M.; Verbruggen, E.; Vicca, S. |
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Title |
Basalt addition improves the performance of young grassland monocultures under more persistent weather featuring longer dry and wet spells |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Agricultural and forest meteorology |
Abbreviated Journal |
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Volume |
340 |
Issue |
1 |
Pages |
109610 |
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Keywords |
A1 Journal article; Plant and Ecosystems (PLECO) – Ecology in a time of change |
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Abstract |
Global warming is altering the intra-annual variability of precipitation patterns in the mid-latitudes, including a shift towards longer dry and wet spells compared to historic averages. Such fluctuations will likely alter soil water and nutrient dynamics of managed ecosystems which could negatively influence their functioning (e.g., productivity and fodder quality). Here, we investigated whether basalt addition could attenuate effects of increasingly persistent precipitation regimes (PR) on two agricultural grassland monocultures differing in drought resistance (low: Lolium perenne (LP) vs high: Festulolium (FL)) and digestibility (high: LP, low: FL), while improving soil C sequestration. In total, 32 experimental mesocosms were subjected to either a low (1-day wet/ dry alternation) or a highly (30-day wet/dry alternation) persistent PR over 120 days, keeping total precipitation equal. In half of these mesocosms, we mixed basalt with the top 20 cm soil layer at a rate of 50 t ha-1. Overall, 30-day PR increased average water availability resulting in improved aboveground biomass and shoot digestibility for both species, in spite of elevated physiological stress. These PR also increased shoot Si, K, N and C but reduced Ca accumulation. Basalt addition generally increased soil Al, Ni, Mg, Ca, P, K and Si availability without altering root biomass or total soil carbon. Moreover, differences in root N content and C:N ratio between species were reduced. Interestingly, basalt modified the PR effects on productivity. Within 30-day PR, basalt stimulated aboveground biomass (& PLUSMN;14%) and root Si and K contents without altering plant digestibility, palatability, crude protein content or Ni/Al content. These results indicate that basalt can stimulate grassland productivity and soil nutrient availability under more persistent PR without negatively affecting fodder quality. Hence, basalt application may improve the performance of young temperate grassland monocultures under climate change, though dry soil conditions may limit effects on soil C sequestration during summer. |
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Place of Publication |
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Wos |
001051084500001 |
Publication Date |
2023-07-21 |
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Series Editor |
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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 |
0168-1923 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:199204 |
Serial |
9189 |
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Author |
Tian, H.; Schryvers, D.; Liu, D.; Jiang, Q.; van Humbeeck, J. |
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Title |
Stability of Ni in nitinol oxide surfaces |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Acta biomaterialia |
Abbreviated Journal |
Acta Biomater |
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Volume |
7 |
Issue |
2 |
Pages |
892-899 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The stability of Ni in titanium oxide surface layers on nitinol wires known to release certain amounts of Ni was investigated by first principles density functional theory and transmission electron microscopy. The oxides were identified as a combination of TiO and TiO2 depending on the thickness of the layer. The calculations indicate that free Ni atoms can exist in TiO at ambient temperature while Ni particles form in TiO2, which was confirmed by the transmission electron microscopy observations. The results are discussed with respect to surface stability and Ni release due to free Ni atoms and Ni particles. |
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Address |
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Corporate Author |
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Publisher |
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Place of Publication |
S.l. |
Editor |
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Language |
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Wos |
000286707700047 |
Publication Date |
2010-09-17 |
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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 |
1742-7061; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.319 |
Times cited |
39 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 6.319; 2011 IF: 4.865 |
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Call Number |
UA @ lucian @ c:irua:85998 |
Serial |
3128 |
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Author |
Hoang, D.-Q.; Korneychuk, S.; Sankaran, K.J.; Pobedinskas, P.; Drijkoningen, S.; Turner, S.; Van Bael, M.K.; Verbeeck, J.; Nicley, S.S.; Haenen, K. |
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Title |
Direct nucleation of hexagonal boron nitride on diamond : crystalline properties of hBN nanowalls |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
127 |
Issue |
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Pages |
17-24 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Hexagonal boron nitride (hBN) nanowalls were deposited by unbalanced radio frequency sputtering on (100)-oriented silicon, nanocrystalline diamond films, and amorphous silicon nitride (Si3N4) membranes. The hBN nanowall structures were found to grow vertically with respect to the surface of all of the substrates. To provide further insight into the nucleation phase and possible lattice distortion of the deposited films, the structural properties of the different interfaces were characterized by transmission electron microscopy. For Si and Si3N4 substrates, turbostratic and amorphous BN phases form a clear transition zone between the substrate and the actual hBN phase of the bulk nanowalls. However, surprisingly, the presence of these phases was suppressed at the interface with a nanocrystalline diamond film, leading to a direct coupling of hBN with the diamond surface, independent of the vertical orientation of the diamond grain. To explain these observations, a growth mechanism is proposed in which the hydrogen terminated surface of the nanocrystalline diamond film leads to a rapid formation of the hBN phase during the initial stages of growth, contrary to the case of Si and Si3N4 substrates. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
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Publication Date |
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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 |
1359-6454 |
ISBN |
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Additional Links |
UA library record; ; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 5.301 |
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Call Number |
UA @ lucian @ c:irua:142398 |
Serial |
4645 |
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Author |
Arseenko, M.; Hannard, F.; Ding, L.; Zhao, L.; Maire, E.; Villanova, J.; Idrissi, H.; Simar, A. |
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Title |
A new healing strategy for metals : programmed damage and repair |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
238 |
Issue |
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Pages |
118241-10 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Self-healing strategies aim at avoiding part repair or even replacement, which is time consuming, expen-sive and generates waste. However, strategies for metallic systems are still under-developed and solid-state solutions for room temperature service are limited to nano-scale damage repair. Here we propose a new healing strategy of micron-sized damage requiring only short and low temperature heating. This new strategy is based on damage localization particles, which can be healed by fast diffusing atoms of the matrix activated during heat treatment. The healing concept was successfully validated with a com-mercial aluminum alloy and manufactured by Friction Stir Processing (FSP). Damage was demonstrated to initiate on particles that were added to the matrix during material processing. In situ 2D and 3D nano -imaging confirmed healing of the damaged material and showed that heating this material for 10 min at 400 degrees C is sufficient to heal incipient damage with complete filling of 70% of all damage (and up to 90% when their initial size is below 0.2 mu m). Furthermore, strength is retained and the work of fracture of the alloy is improved by about 40% after healing. The proposed Programmed Damage and Repair healing strategy could be extended to other metal based systems presenting precipitation. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000843502700006 |
Publication Date |
2022-08-03 |
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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 |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
9.4 |
Times cited |
|
Open Access |
Not_Open_Access |
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| |
Notes |
|
Approved |
Most recent IF: 9.4 |
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| |
Call Number |
UA @ admin @ c:irua:190561 |
Serial |
7121 |
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| Permanent link to this record |
| |
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| |
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Author |
Weng, Y.; Ding, L.; Zhang, Z.; Jia, Z.; Wen, B.; Liu, Y.; Muraishi, S.; Li, Y.; Liu, Q. |
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| |
Title |
Effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloy |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
180 |
Issue |
180 |
Pages |
301-316 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloys was systematically investigated by atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), atom probe tomography (APT) and density functional theory (DFT) calculation. At the early aging stage, Ag atoms could enter clusters and refine the distribution of these clusters. Then, Ag atoms preferentially segregate at the GP zone/alpha-Al and beta ''/alpha-Al interfaces at the peak aging stage by the replacement of Al atoms in FCC matrix. With prolonging aging time, Ag atoms generally incorporate into the interior of beta '' precipitate, facilitating the formation of QP lattice (a hexagonal network of Si atomic columns) and the local symmetry substructures, Ag sub-unit (1) and Ag sub-unit (2). At the over-aged stage, the Ag sub-unit (1) and Ag sub-unit (2) could transform to the beta'(Ag) (i.e. beta'(Ag1) and beta'(Ag2).) and Q'(Ag) unit cells, respectively. All the precipitates at the over-aging stage have a composite and disordered structure due to the coexistence of different unit cells (beta'(Ag1), beta'(Ag2), Q'(Ag) and beta') and the non-periodic arrangement of Ag atoms within the precipitate. In the equilibrium stage, the incorporated Ag atoms in the precipitates release into the alpha-Al matrix as solute atoms or form Ag particles. In general, Ag atoms undergo a process of “segregate at the precipitate/matrix interface -> incorporate into the interior of precipitate -> release into the alpha-Al matrix” during the precipitation for Al-Mg-Si-Ag alloys. Besides, Ag segregation is found at the interfaces of almost all metastable phases (including GP zone, beta '', beta'/beta'(Ag) phase) in Al-Mg-Si-Ag alloys. The Ag segregation at the beta'/alpha-Al interface could increase the length/diameter ratio of beta' phase and thus promote the additional strengthening potential of these alloys. These findings provide a new route for precipitation hardening by promoting the nucleation and morphology evolution of precipitates. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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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 |
|
Wos |
000495519100028 |
Publication Date |
2019-09-12 |
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| |
Series Editor |
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Series Title |
|
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 |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 5.301 |
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| |
Call Number |
UA @ admin @ c:irua:164641 |
Serial |
6295 |
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| Permanent link to this record |
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| |
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Author |
Zhang, Z.; Rosalie, J.M.; Medhekar, N.V.; Bourgeois, L. |
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| |
Title |
Resolving the FCC/HCP interfaces of the \gamma'(Ag2Al) precipitate phase in aluminium |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
174 |
Issue |
174 |
Pages |
116-130 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The gamma'(Ag2Al) phase in the Al-Ag alloy system has served as a textbook example for understanding phase transformations, precipitating hexagonal close-packed (HCP) crystals in the face-centred cubic (FCC) aluminium matrix. The gamma' precipitates display fully coherent interfaces at their broad facets and semicoherent interfaces at their edges. Shockley partial dislocations are expected to decorate the semicoherent interface due to the FCC-HCP structural transformation. Determining the exact locations and core structures of interfacial dislocations, however, remains challenging. In this study, we used aberration-corrected scanning transmission electron microscopy and atomistic simulations to re-visit this classical system. We characterised and explained the Ag segregation at coherent interfaces in the early stage of precipitation. For semicoherent interfaces, interfacial dislocations and reconstructions were revealed by bridging advanced microstructure characterisation and atomistic simulations. In particular, we discovered a new FCC/HCP interfacial structure that displays a unique combination of Shockley partial, Lomer-Cottrell and Hirth dislocations that evolve from the known interfacial structure purely composed by Shockley partial dislocations. Our findings show that the FCC-HCP transformation is more complex than hitherto considered, due to the interplay between structure and composition confined at interfaces. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000474501300011 |
Publication Date |
2019-05-18 |
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| |
Series Editor |
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Series Title |
|
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 |
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| |
Impact Factor |
5.301 |
Times cited |
3 |
Open Access |
|
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| |
Notes |
; The authors acknowledge funding from the Australian Research Council (LE0454166, LE110100223), the Victorian State Government and Monash University for instrumentation, and use of the facilities within the Monash Centre for Electron Microscopy. LB and NM acknowledge the financial support of the Australian Research Council (DP150100558). The authors also gratefully acknowledge the computational support from Monash Advanced Research Computing Hybrid, the National Computational Infrastructure and Pawsey Supercomputing Centre. ZZ is thankful to Monash University for a Monash Graduate Scholarship, a Monash International Postgraduate Research Scholarship and a Monash Centre for Electron Microscopy Postgraduate Scholarship. ZZ is indebted to Matthew Weyland for his training in aberration-corrected electron microscopy, Scott Findlay for his help on image simulations, Xiang Gao for alloy casting and Ian Polmear for discussions. ; |
Approved |
Most recent IF: 5.301 |
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| |
Call Number |
UA @ admin @ c:irua:161192 |
Serial |
5395 |
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| Permanent link to this record |
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| |
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Author |
Lemoine, G.; Delannay, L.; Idrissi, H.; Colla, M.-S.; Pardoen, T. |
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| |
Title |
Dislocation and back stress dominated viscoplasticity in freestanding sub-micron Pd films |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
111 |
Issue |
111 |
Pages |
10-21 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
A dislocation-based crystal plasticity model is developed in order to study the mechanical and creep/ relaxation behaviour of polycrystalline metallic thin films. The model accounts for the confinement of plasticity due to grain boundaries and for the anisotropy of individual grains, as well as for the significant viscoplastic effects associated to dislocation dominated thermally activated mechanisms. Numerical predictions are assessed based on experimental tensile test followed by relaxation on freestanding Pd films, based on an on-chip test technique. The dislocation-based mechanism assumption captures all the experimental trends, including the stress strain response, the relaxation behaviour and the dislocation density evolution, confirming the dominance of a dislocation driven deformation mechanism for the present Pd films with high defects density. The model has also been used to address some original experimental evidences involving back stresses, Bauschinger effect, backward creep and strain recovery. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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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 |
|
Wos |
000375812100002 |
Publication Date |
2016-03-26 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
6 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 5.301 |
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| |
Call Number |
UA @ lucian @ c:irua:133636 |
Serial |
4162 |
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| Permanent link to this record |
| |
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| |
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Author |
Wang, X.; Kustov, S.; Li, K.; Schryvers, D.; Verlinden, B.; Van Humbeeck, J. |
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| |
Title |
Effect of nanoprecipitates on the transformation behavior and functional properties of a Ti50.8 at.% Ni alloy with micron-sized grains |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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| |
Volume |
82 |
Issue |
82 |
Pages |
224-233 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
In order to take advantage of both grain refinement and precipitation hardening effects, nanoscaled Ni4Ti3 precipitates are introduced in a Ti50.8 at.% Ni alloy with micron-sized grains (average grain size of 1.7 μm). Calorimetry, electrical resistance studies and thermomechanical tests were employed to study the transformation behavior and functional properties in relation to the obtained microstructure. A significant suppression of martensite transformation by the obtained microstructure is observed. The thermomechanical tests show that the advantageous properties of both grain refinement and precipitation hardening are combined in the developed materials, resulting in superior shape memory characteristics and stability of pseudoelasticity. It is concluded that introducing nanoscaled Ni4Ti3 precipitates into small grains is a new approach to improve the functional properties of NiTi shape memory alloys. |
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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 |
000347017800021 |
Publication Date |
2014-10-04 |
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| |
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 |
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| |
Impact Factor |
5.301 |
Times cited |
51 |
Open Access |
|
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| |
Notes |
Fwo |
Approved |
Most recent IF: 5.301; 2015 IF: 4.465 |
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| |
Call Number |
c:irua:120469 |
Serial |
824 |
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| Permanent link to this record |
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Author |
Shi, H.; Frenzel, J.; Martinez, G.T.; Van Rompaey, S.; Bakulin, A.; Kulkova, A.; Van Aert, S.; Schryvers, D. |
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| |
Title |
Site occupation of Nb atoms in ternary Ni-Ti-Nb shape memory alloys |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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| |
Volume |
74 |
Issue |
|
Pages |
85-95 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Nb occupancy in the austenite B2-NiTi matrix and Ti2Ni phase in NiTiNb shape memory alloys was investigated by aberration-corrected scanning transmission electron microscopy and precession electron diffraction. In both cases, Nb atoms were found to prefer to occupy the Ti rather than Ni sites. A projector augmented wave method within density functional theory was used to calculate the atomic and electronic structures of the austenitic B2-NiTi matrix phase and the Ti2Ni precipitates both with and without addition of Nb. The obtained formation energies and analysis of structural and electronic characteristics explain the preference for Ti sites for Nb over Ni sites. |
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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 |
000338621400009 |
Publication Date |
2014-05-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
21 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 5.301; 2014 IF: 4.465 |
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| |
Call Number |
UA @ lucian @ c:irua:118334 |
Serial |
3028 |
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| Permanent link to this record |
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Author |
Colla, M.-S.; Wang, B.; Idrissi, H.; Schryvers, D.; Raskin, J.-P.; Pardoen, T. |
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Title |
High strength-ductility of thin nanocrystalline palladium films with nanoscale twins : on-chip testing and grain aggregate model |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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| |
Volume |
60 |
Issue |
4 |
Pages |
1795-1806 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The mechanical behaviour of thin nanocrystalline palladium films with an ∼30 nm in plane grain size has been characterized on chip under uniaxial tension. The films exhibit a large strain hardening capacity and a significant increase in the strength with decreasing thickness. Transmission electron microscopy has revealed the presence of a moderate density of growth nanotwins interacting with dislocations. A semi-analytical grain aggregate model is proposed to investigate the impact of different contributions to the flow behaviour, involving the effect of twins, of grain size and of the presence of a thin surface layer. This model provides guidelines to optimizing the strength/ductility ratio of the films. |
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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 |
000301989500035 |
Publication Date |
2012-02-02 |
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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 |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
38 |
Open Access |
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| |
Notes |
Iap |
Approved |
Most recent IF: 5.301; 2012 IF: 3.941 |
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| |
Call Number |
UA @ lucian @ c:irua:94213 |
Serial |
1465 |
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| Permanent link to this record |
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| |
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Author |
Tirumalasetty, G.K.; van Huis, M.A.; Kwakernaak, C.; Sietsma, J.; Sloof, W.G.; Zandbergen, H.W. |
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Title |
Deformation-induced austenite grain rotation and transformation in TRIP-assisted steel |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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| |
Volume |
60 |
Issue |
3 |
Pages |
1311-1321 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Uniaxial straining experiments were performed on a rolled and annealed Si-alloyed TRIP (transformation-induced plasticity) steel sheet in order to assess the role of its microstructure on the mechanical stability of austenite grains with respect to martensitic transformation. The transformation behavior of individual metastable austenite grains was studied both at the surface and inside the bulk of the material using electron back-scattered diffraction (EBSD) and X-ray diffraction (XRD) by deforming the samples to different strain levels up to about 20%. A comparison of the XRD and EBSD results revealed that the retained austenite grains at the surface have a stronger tendency to transform than the austenite grains in the bulk of the material. The deformation-induced changes of individual austenite grains before and after straining were monitored with EBSD. Three different types of austenite grains can be distinguished that have different transformation behaviors: austenite grains at the grain boundaries between ferrite grains, twinned austenite grains, and embedded austenite grains that are completely surrounded by a single ferrite grain. It was found that twinned austenite grains and the austenite grains present at the grain boundaries between larger ferrite grains typically transform first, i.e. are less stable, in contrast to austenite grains that are completely embedded in a larger ferrite grain. In the latter case, straining leads to rotations of the harder austenite grain within the softer ferrite matrix before the austenite transforms into martensite. The analysis suggests that austenite grain rotation behavior is also a significant factor contributing to enhancement of the ductility. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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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 |
|
Wos |
000301157900054 |
Publication Date |
2011-12-19 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
80 |
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: 5.301; 2012 IF: 3.941 |
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| |
Call Number |
UA @ lucian @ c:irua:97210 |
Serial |
630 |
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| Permanent link to this record |
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Author |
Tirumalasetty, G.K.; van Huis, M.A.; Fang, C.M.; Xu, Q.; Tichelaar, F.D.; Hanlon, D.N.; Sietsma, J.; Zandbergen, H.W. |
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| |
Title |
Characterization of NbC and (Nb, Ti)N nanoprecipitates in TRIP assisted multiphase steels |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
59 |
Issue |
19 |
Pages |
7406-7415 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
Multiphase steels utilising composite strengthening may be further strengthened via grain refinement or precipitation by the addition of microalloying elements. In this study a Nb microalloyed steel comprising martensite, bainite and retained austenite has been studied. By means of transmission electron microscopy (TEM) we have investigated the size distribution and the structural properties of (Nb, Ti)N and NbC precipitates, their occurrence in the various steel phases, and their relationship with the Fe matrix. (Nb, Ti)N precipitates were found in ferrite, martensite, and bainite, while NbC precipitates were found only in ferrite. All NbC precipitates were found to be small (520 nm in size) and to have a face centred cubic (fcc) crystal structure with lattice parameter a = 4.36 ± 0.05 Å. In contrast, the (Nb, Ti)N precipitates were found to have a broader size range (5150 nm) and to have a fcc crystal structure with lattice parameter a = 8.09 ± 0.05 Å. While the NbC precipitates were found to be randomly oriented, the (Nb, Ti)N precipitates have a well-defined NishiyamaWasserman orientation relationship with the ferrite matrix. An analysis of the lattice mismatch suggests that the latter precipitates have a high potential for effective strengthening. Density functional theory calculations were performed for various stoichiometries of NbCx and NbxTiyNz phases and the comparison with experimental data indicates that both the carbides and nitrides are deficient in C and N content. |
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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 |
000296405200026 |
Publication Date |
2011-09-29 |
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| |
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 |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
58 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
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| |
Call Number |
UA @ lucian @ c:irua:93297 |
Serial |
328 |
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| Permanent link to this record |
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Author |
Chen, X.; Cao, S.; Ikeda, T.; Srivastava, V.; Snyder, G.J.; Schryvers, D.; James, R.D. |
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| |
Title |
A weak compatibility condition for precipitation with application to the microstructure of PbTe-Sb2Te3 thermoelectrics |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
59 |
Issue |
15 |
Pages |
6124-6132 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
We propose a weak condition of compatibility between phases applicable to cases exhibiting full or partial coherence and Widmanstätten microstructure. The condition is applied to the study of Sb2Te3 precipitates in a PbTe matrix in a thermoelectric alloy. The weak condition of compatibility predicts elongated precipitates lying on a cone determined by a transformation stretch tensor. Comparison of this cone with the long directions of precipitates determined by a slice-and-view method of scanning electron microscopy combined with focused ion beam sectioning shows good agreement between theory and experiment. A further study of the morphology of precipitates by the Eshelby method suggests that interfacial energy also plays a role and gives an approximate value of interfacial energy per unit area of 250 dyn cm−1. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
Oxford |
Editor |
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| |
Language |
|
Wos |
000294086900026 |
Publication Date |
2011-07-22 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
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| |
Call Number |
UA @ lucian @ c:irua:92388 |
Serial |
3911 |
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| Permanent link to this record |
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| |
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Author |
Cao, S.; Nishida, M.; Schryvers, D. |
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| |
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 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
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. |
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Place of Publication |
Oxford |
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Wos |
000287265100045 |
Publication Date |
2010-12-20 |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
34 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
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Call Number |
UA @ lucian @ c:irua:85533 |
Serial |
2766 |
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Author |
Malard, B.; Pilch, J.; Sittner, P.; Delville, R.; Curfs, C. |
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Title |
In situ investigation of the fast microstructure evolution during electropulse treatment of cold drawn NiTi wires |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
59 |
Issue |
4 |
Pages |
1542-1556 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Microstructural changes taking place during the heat treatment of cold-worked NiTi alloy are of key interest in shape memory alloy technology, since they are responsible for setting the austenite shape and functional properties of the heat-treated alloy. In this work, microstructural evolution during non-conventional electropulse heat treatment of thin NiTi filaments was investigated in a unique high-speed in situ synchrotron X-ray diffraction experiment with simultaneous evaluation of the tensile force and electrical resistivity of the treated wire. The in situ results provide direct experimental evidence on the evolution of the internal stress and density of defects during fast heating from 20 °C to ∼700 °C. This evidence is used to characterize a sequence of dynamic recovery and recrystallization processes responsible for the microstructure and superelastic functional property changes during the electropulse treatments. |
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Place of Publication |
Oxford |
Editor |
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Wos |
000287265100023 |
Publication Date |
2010-12-11 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
48 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.301; 2011 IF: 3.755 |
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Call Number |
UA @ lucian @ c:irua:98372 |
Serial |
1583 |
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Author |
Delville, R.; Malard, B.; Pilch, J.; Schryvers, D. |
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Title |
Microstructure changes during non-conventional heat treatment of thin NiTi wires by pulsed electric current studied by transmission electron microscopy |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
58 |
Issue |
13 |
Pages |
4503-4515 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Transmission electron microscopy, electrical resistivity measurements and mechanical testing were employed to investigate the evolution of microstructure and functional superelastic properties of 0.1 mm diameter as-drawn NiTi wires subjected to a non-conventional heat treatment by controlled electric pulse currents. This method enables a better control of the recovery and recrystallization processes taking place during the heat treatment and accordingly a better control on the final microstructure. Using a stepwise approach of millisecond pulse annealing, it is shown how the microstructure evolves from a severely deformed state with no functional properties to an optimal nanograined microstructure (2050 nm) that is partially recovered through polygonization and partially recrystallized and that has the best functional properties. Such a microstructure is highly resistant against dislocation slip upon cycling, while microstructures annealed for longer times and showing mostly recrystallized grains were prone to dislocation slip, particularly as the grain size exceeds 200 nm. |
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Place of Publication |
Oxford |
Editor |
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Wos |
000279787100020 |
Publication Date |
2010-06-02 |
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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 |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
110 |
Open Access |
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Notes |
Multimat; FWO
IAA |
Approved |
Most recent IF: 5.301; 2010 IF: 3.791 |
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Call Number |
UA @ lucian @ c:irua:83279 |
Serial |
2062 |
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Author |
Idrissi, H.; Renard, K.; Ryelandt, L.; Schryvers, D.; Jacques, P.J. |
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Title |
On the mechanism of twin formation in FeMnC TWIP steels |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
58 |
Issue |
7 |
Pages |
2464-2476 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Although it is well known that FeMnC TWIP steels exhibit high work-hardening rates, the elementary twinning mechanisms controlling the plastic deformation of these steels have still not been characterized. The aim of the present study is to analyse the extended defects related to the twinning occurrence using transmission electron microscopy. Based on these observations, the very early stage of twin nucleation can be attributed to the pole mechanism with deviation proposed by Cohen and Weertman or to the model of Miura, Takamura and Narita, while the twin growth is controlled by the pole mechanism proposed by Venables. High densities of sessile Frank dislocations are observed within the twins at the early stage of deformation, which can affect the growth and the stability of the twins, but also the strength of these twins and their interactions with the gliding dislocations present in the matrix. This experimental evidence is discussed and compared to recent results in order to relate the defects analysis to the macroscopic behaviour of this category of material. |
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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 |
000276523200018 |
Publication Date |
2010-01-25 |
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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 |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
244 |
Open Access |
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Notes |
Iap |
Approved |
Most recent IF: 5.301; 2010 IF: 3.791 |
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Call Number |
UA @ lucian @ c:irua:82270 |
Serial |
2441 |
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