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“Cobalt location in p -CoO x / n -SnO 2 nanocomposites: Correlation with gas sensor performances”. Vladimirova SA, Rumyantseva MN, Filatova DG, Chizhov AS, Khmelevsky NO, Konstantinova EA, Kozlovsky VF, Marchevsky AV, Karakulina OM, Hadermann J, Gaskov AM, Journal Of Alloys And Compounds 721, 249 (2017). http://doi.org/10.1016/j.jallcom.2017.05.332
Abstract: Nanocomposites CoOx/SnO2 based on tin oxide powders with different crystallinity have been prepared by wet chemical synthesis and characterized in detail by ICP-MS, XPS, EPR, XRD, HAADF-STEM imaging and EDX-STEM mapping. It was shown that cobalt is distributed differently between the bulk and surface of SnO2 nanocrystals, which depends on the crystallinity of the SnO2 matrix. The measurements of gas sensor properties have been carried out during exposure to CO (10 ppm), and H2S (2 ppm) in dry air. The decrease of sensor signal toward CO was attributed to high catalytic activity of Co3O4 leading to oxidation of carbon monoxide entirely on the surface of catalyst particles. The formation of a p-CoOx/n-SnO2 heterojunction results in high sensitivity of nanocomposites in H2S detection. The conductance significantly changed in the presence of H2S, which was attributed to the formation of metallic cobalt sulfide and removal of the p – n junction.
Keywords: A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Impact Factor: 3.133
DOI: 10.1016/j.jallcom.2017.05.332
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“Take out the farmer: An economic assessment of land expropriation for urban expansion in Bahir Dar, Northwest Ethiopia”. Admasu WF, Van Passel S, Minale AS, Tsegaye EA, Azadi H, Nyssen J, Land Use Policy 87, 104038 (2019). http://doi.org/10.1016/J.LANDUSEPOL.2019.104038
Abstract: In Ethiopia, the demand for land for urbanisation is primarily met by converting rural land through expropriation. However, land expropriations are adversely affecting the previous land users by reducing the amount of production and their sources of income. In Bahir Dar, one of the fastest-growing cities in Ethiopia, approximately 300 landholdings are expropriated each year, on average, for urban expansion. This paper assesses the land expropriations to examine whether they offer economically appropriate compensation for the previous land users. Land expropriations for urbanisation between 2007/2008 and 2016/2017 were analysed based on data on land expropriation and its compensation payment obtained from the Bahir Dar City Land Administration and Management Office. Data were analysed using an exponential growth model and a stochastic budgeting technique in which Monte Carlo simulations are performed. Between 2007/2008 and 2016/2017, more than 1500 ha of land were included in the city's boundary through expropriation from 2900 landholders. The affected farmers received compensation that represents only 37 per cent of the value of current crop yields and its growth. The current compensation scheme ignores the impact of inflation on the prices of crops and assumes constant yields. It also excludes the value of crop residuals. We propose a workable discounted compensation framework that considers crop price and yield growths. This will make the compensation scheme more appropriate and make the affected farmers better off.
Keywords: A1 Journal article; Engineering Management (ENM)
Impact Factor: 3.089
Times cited: 1
DOI: 10.1016/J.LANDUSEPOL.2019.104038
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“Agricultural technical efficiency of smallholder farmers in Ethiopia : a stochastic frontier approach”. Chekol Zewdie M, Moretti M, Tenessa DB, Ayele ZA, Nyssen J, Tsegaye EA, Minale AS, Van Passel S, Land 10, 246 (2021). http://doi.org/10.3390/LAND10030246
Abstract: In the past decade, to improve crop production and productivity, Ethiopia has embarked on an ambitious irrigation farming expansion program and has introduced new large- and small-scale irrigation initiatives. However, in Ethiopia, poverty remains a challenge, and crop productivity per unit area of land is very low. Literature on the technical efficiency (TE) of large-scale and small-scale irrigation user farmers as compared to the non-user farmers in Ethiopia is also limited. Investigating smallholder farmers' TE level and its principal determinants is very important to increase crop production and productivity and to improve smallholder farmers' livelihood and food security. Using 1026 household-level cross-section data, this study adopts a technology flexible stochastic frontier approach to examine agricultural TE of large-scale irrigation users, small-scale irrigation users and non-user farmers in Ethiopia. The results indicate that, due to poor extension services and old-style agronomic practices, the mean TE of farmers is very low (44.33%), implying that there is a wider room for increasing crop production in the study areas through increasing the TE of smallholder farmers without additional investment in novel agricultural technologies. Results also show that large-scale irrigation user farmers (21.05%) are less technically efficient than small-scale irrigation user farmers (60.29%). However, improving irrigation infrastructure shifts the frontier up and has a positive impact on smallholder farmers' output.
Keywords: A1 Journal article; Engineering Management (ENM)
DOI: 10.3390/LAND10030246
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“Uncovering ecosystem services of expropriated land : the case of urban expansion in Bahir Dar, Northwest Ethiopia”. Admasu WF, Boerema A, Nyssen J, Minale AS, Tsegaye EA, Van Passel S, Land 9, 395 (2020). http://doi.org/10.3390/LAND9100395
Abstract: In Ethiopia, urban expansion happens at high rates and results in land expropriations often at the cost of agriculture and forests. The process of urban expansion does not include assessment of ecosystem services (ES). This has been causing unintended environmental problems. This study aims to uncover ES of three most important land use types (cropland, agroforestry, and grassland) that are threatened by land expropriation for urban expansion in Bahir Dar City. The study applied a participatory approach using community perception and expert judgments (N = 108). Respondents were asked to locate their perceptions on the use of 35 different ES, and then to evaluate the potential of the land use. Respondents were shown to have the ability to differentiate between ES and land use in terms of their potential to deliver ES. The results show that agroforestry is expected to have a high relevant potential to deliver 31% of all ES, but cropland 20% and grassland 14%. Food, fodder, timber, firewood, fresh water, energy, compost, climate regulation, erosion prevention, and water purification and treatment were identified as the ten most important services. It is not only the provisioning services that are being supplied by the land use types which are expropriated for urbanization, but also regulating, supporting and cultural services. To ensure sustainable urban land development, we suggest the consideration of the use of ES and the potential of the land use to supply ES when making land use decisions, including land expropriation for urban expansion.
Keywords: A1 Journal article; Engineering Management (ENM); Ecosystem Management
DOI: 10.3390/LAND9100395
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“Enhanced self-assembly of metal oxides and metal-organic frameworks from precursors with magnetohydrodynamically induced long-lived collective spin states”. Breynaert E, Emmerich J, Mustafa D, Bajpe SR, Altantzis T, Van Havenbergh K, Taulelle F, Bals S, Van Tendeloo G, Kirschhock CEA, Martens JA;, Advanced materials 26, 5173 (2014). http://doi.org/10.1002/adma.201400835
Abstract: Magneto-hydrodynamic generation of long-lived collective spin states and their impact on crystal morphology is demonstrated for three different, technologically relevant materials: COK-16 metal organic framework, manganese oxide nanotubes, and vanadium oxide nano-scrolls.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 7
DOI: 10.1002/adma.201400835
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“Global and local superconductivity in boron-doped granular diamond”. Zhang G, Turner S, Ekimov EA, Vanacken J, Timmermans M, Samuely T, Sidorov VA, Stishov SM, Lu Y, Deloof B, Goderis B, Van Tendeloo G, Van de Vondel J, Moshchalkov VV;, Advanced materials 26, 2034 (2014). http://doi.org/10.1002/adma.201304667
Abstract: Strong granularity-correlated and intragrain modulations of the superconducting order parameter are demonstrated in heavily boron-doped diamond situated not yet in the vicinity of the metal-insulator transition. These modulations at the superconducting state (SC) and at the global normal state (NS) above the resistive superconducting transition, reveal that local Cooper pairing sets in prior to the global phase coherence.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 19.791
Times cited: 34
DOI: 10.1002/adma.201304667
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“Role of PdOx and RuOy clusters in oxygen exchange between nanocrystalline tin dioxide and the gas phase”. Marikutsa AV, Rumyantseva MN, Frolov DD, Morozov IV, Boltalin AI, Fedorova AA, Petukhov IA, Yashina LV, Konstantinova EA, Sadovskaya EM, Abakumov AM, Zubavichus YV, Gaskov AM;, The journal of physical chemistry: C : nanomaterials and interfaces 117, 23858 (2013). http://doi.org/10.1021/jp408646k
Abstract: The effect of palladium- and ruthenium-based clusters on nanocrystalline tin dioxide interaction with oxygen was studied by temperature-programmed oxygen isotopic exchange with mass-spectrometry detection. The modification of aqueous sol-gel prepared SnO2 by palladium and, to a larger extent, by ruthenium, increases surface oxygen concentration on the materials. The revealed effects on oxygen exchange-lowering the threshold temperature, separation of surface oxygen contribution to the process, increase of heteroexchange rate and oxygen diffusion coefficient, decrease of activation energies of exchange and diffusion-were more intensive for Ru-modified SnO2 than in the case of SnO2/Pd. The superior promoting activity of ruthenium on tin dioxide interaction with oxygen was interpreted by favoring the dissociative O-2 adsorption and increasing the oxygen mobility, taking into account the structure and chemical composition of the modifier clusters.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 20
DOI: 10.1021/jp408646k
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“Vapor phase processing of \alpha-Fe2O3 photoelectrodes for water splitting : an insight into the structure/property interplay”. Warwick MEA, Kaunisto K, Barreca D, Carraro G, Gasparotto A, Maccato C, Bontempi E, Sada C, Ruoko TP, Turner S, Van Tendeloo G;, ACS applied materials and interfaces 7, 8667 (2015). http://doi.org/10.1021/acsami.5b00919
Abstract: Harvesting radiant energy to trigger water photoelectrolysis and produce clean hydrogen is receiving increasing attention in the search of alternative energy resources. In this regard, hematite (alpha-Fe2O3) nanostructures with controlled nano-organization have been fabricated and investigated for use as anodes in photoelectrochemical (PEC) cells. The target systems have been grown on conductive substrates by plasma enhanced-chemical vapor deposition (PE-CVD) and subjected to eventual ex situ annealing in air to further tailor their structure and properties. A detailed multitechnique approach has enabled to elucidate between system characteristics and the generated photocurrent. The present alpha-Fe2O3 systems are characterized by a high purity and hierarchical morphologies consisting of nanopyramids/organized dendrites, offering a high contact area with the electrolyte. PEC data reveal a dramatic response enhancement upon thermal treatment, related to a more efficient electron transfer. The reasons underlying such a phenomenon are elucidated and discussed by transient absorption spectroscopy (TAS) studies of photogenerated charge carrier kinetics, investigated on different time scales for the first time on PE-CVD Fe2O3 nanostructures.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.504
Times cited: 51
DOI: 10.1021/acsami.5b00919
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“Catalyst design by NH4OH treatment of USY zeolite”. Van Aelst J, Verboekend D, Philippaerts A, Nuttens N, Kurttepeli M, Gobechiya E, Haouas M, Sree SP, Denayer JFM, Martens JA, Kirschhock CEA, Taulelle F, Bals S, Baron GV, Jacobs PA, Sels BF, Advanced functional materials 25, 7130 (2015). http://doi.org/10.1002/adfm.201502772
Abstract: Hierarchical zeolites are a class of superior catalysts which couples the intrinsic zeolitic properties to enhanced accessibility and intracrystalline mass transport to and from the active sites. The design of hierarchical USY (Ultra-Stable Y) catalysts is achieved using a sustainable postsynthetic room temperature treatment with mildly alkaline NH4OH ( 0.02(M)) solutions. Starting from a commercial dealuminated USY zeolite (Si/Al = 47), a hierarchical material is obtained by selective and tuneable creation of interconnected and accessible small mesopores (2- 6 nm). In addition, the treatment immediately yields the NH4+ form without the need for additional ion exchange. After NH4OH modification, the crystal morphology is retained, whereas the microporosity and relative crystallinity are decreased. The gradual formation of dense amorphous phases throughout the crystal without significant framework atom leaching rationalizes the very high material yields (>90%). The superior catalytic performance of the developed hierarchical zeolites is demonstrated in the acid-catalyzed isomerization of alpha-pinene and the metal-catalyzed conjugation of safflower oil. Significant improvements in activity and selectivity are attained, as well as a lowered susceptibility to deactivation. The catalytic performance is intimately related to the introduced mesopores, hence enhanced mass transport capacity, and the retained intrinsic zeolitic properties.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.124
Times cited: 64
DOI: 10.1002/adfm.201502772
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“Hematite-based nanocomposites for light-activated applications: Synergistic role of TiO2 and Au introduction”. Carraro G, Maccato C, Gasparotto A, Warwick MEA, Sada C, Turner S, Bazzo A, Andreu T, Pliekhova O, Korte D, Lavrenčič, Štangar U, Van Tendeloo G, Morante JR, Barreca D, Solar energy materials and solar cells 159, 456 (2017). http://doi.org/10.1016/j.solmat.2016.09.037
Abstract: Photo-activated processes have been widely recognized as cost-effective and environmentally friendly routes for both renewable energy generation and purification/cleaning technologies. We report herein on a plasma- assisted approach for the synthesis of Fe 2 O 3 -TiO 2 nanosystems functionalized with Au nanoparticles. Fe 2 O 3 nanostructures were grown by plasma enhanced-chemical vapor deposition, followed by the sequential sputtering of titanium and gold under controlled conditions, and final annealing in air. The target nanosystems were subjected to a thorough multi-technique characterization, in order to elucidate the interrelations between their chemico-physical properties and the processing conditions. Finally, the functional performances were preliminarily investigated in both sunlight-assisted H 2 O splitting and photocatalytic activity tests in view of self- cleaning applications. The obtained results highlight the possibility of tailoring the system behaviour and candidate the present Fe 2 O 3 -TiO 2 -Au nanosystems as possible multi-functional low-cost platforms for light-activated processes.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.784
Times cited: 15
DOI: 10.1016/j.solmat.2016.09.037
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“A Comprehensive Study of the Electrodeposition of Nickel Nanostructures from Deep Eutectic Solvents: Self-Limiting Growth by Electrolysis of Residual Water”. Mernissi Cherigui EA, Sentosun K, Bouckenooge P, Vanrompay H, Bals S, Terryn H, Ustarroz J, The journal of physical chemistry: C : nanomaterials and interfaces 121, 9337 (2017). http://doi.org/10.1021/acs.jpcc.7b01104
Abstract: The electrodeposition of nickel nanostructures on glassy carbon was investigated in 1:2 choline chloride – urea (1:2 ChCl-U) deep eutectic solvent (DES). By combining electrochemical techniques with ex-situ FE-SEM, XPS, HAADF-STEM and EDX, the electrochemical processes occurring during nickel deposition were better understood. Special attention was given to the interaction between the solvent and the growing nickel nanoparticles. The application of a suffciently negative potential results into the electrocatlytic hydrolisis of residual water in the DES, which leads to the formation of a mixed layer of Ni/Ni(OH)2(ads). In addition, hydrogen bonds between hydroxide species and the DES components could be formed, quenching the growth of the nickel clusters favouring their aggregation. Due to these processes, a highly dense distribution of nickel nanostructures can be obtained within a wide potential range. Understanding the role of residual water and the interactions at the interface during metal electrodeposition from DESs is essential to produce supported nanostructures in a controllable way for a broad range of applications and technologies.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 66
DOI: 10.1021/acs.jpcc.7b01104
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“3D porous nanostructured platinum prepared using atomic layer deposition”. Pulinthanathu Sree S, Dendooven J, Geerts L, Ramachandran RK, Javon E, Ceyssens F, Breynaert E, Kirschhock CEA, Puers R, Altantzis T, Van Tendeloo G, Bals S, Detavernier C, Martens JA, Journal of materials chemistry A : materials for energy and sustainability 5, 19007 (2017). http://doi.org/10.1039/C7TA03257A
Abstract: A robust and easy to handle 3D porous platinum structure was created via replicating the 3D channel system
of an ordered mesoporous silica material using atomic layer deposition (ALD) over micrometer distances.
After ALD of Pt in the silica material, the host template was digested using hydrogen fluoride (HF). A fully
connected ordered Pt nanostructure was obtained with morphology and sizes corresponding to that of
the pores of the host matrix, as revealed with high-resolution scanning transmission electron
microscopy and electron tomography. The Pt nanostructure consisted of hexagonal Pt rods originating
from the straight mesopores (11 nm) of the host structure and linking features resulting from Pt
replication of the interconnecting mesopore segments (2–4 nm) present in the silica host structure.
Electron tomography of partial replicas, made by incomplete infilling of Zeotile-4 material with Pt,
provided insight in the connectivity and formation mechanism of the Pt nanostructure by ALD. The Pt
replica was evaluated for its potential use as electrocatalyst for the hydrogen evolution reaction, one of
the half-reactions of water electrolysis, and as microelectrode for biomedical sensing. The Pt replica
showed high activity for the hydrogen evolution reaction and electrochemical characterization revealed
a large impedance improvement in comparison with reference Pt electrodes.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 8.867
Times cited: 9
DOI: 10.1039/C7TA03257A
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“Cobalt location in p-CoOxIn-SnO2 nanocomposites : correlation with gas sensor performances”. Vladimirova SA, Rumyantseva MN, Filatova DG, Chizhov AS, Khmelevsky NO, Konstantinova EA, Kozlovsky VF, Marchevsky AV, Karakulina OM, Hadermann J, Gaskov AM, Journal of alloys and compounds 721, 249 (2017). http://doi.org/10.1016/JJALLCOM.2017.05.332
Abstract: Nanocomposites CoOx/SnO2 based on tin oxide powders with different crystallinity have been prepared by wet chemical synthesis and characterized in detail by ICP-MS, XPS, EPR, XRD, HAADF-STEM imaging and EDX-STEM mapping. It was shown that cobalt is distributed differently between the bulk and surface of SnO2 nanocrystals, which depends on the crystallinity of the SnO2 matrix. The measurements of gas sensor properties have been carried out during exposure to CO (10 ppm), and H2S (2 ppm) in dry air. The decrease of sensor signal toward CO was attributed to high catalytic activity of Co3O4 leading to oxidation of carbon monoxide entirely on the surface of catalyst particles. The formation of a p-CoOx/n-SnO2 heterojunction results in high sensitivity of nanocomposites in H2S detection. The conductance significantly changed in the presence of H2S, which was attributed to the formation of metallic cobalt sulfide and removal of the p – n junction. (C) 2017 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 3.133
DOI: 10.1016/JJALLCOM.2017.05.332
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“On the control and effect of water content during the electrodeposition of Ni nanostructures from deep eutectic solvents”. Cherigui EAM, Şentosun K, Mamme MH, Lukaczynska M, Terryn H, Bals S, Ustarroz J, The journal of physical chemistry: C : nanomaterials and interfaces 122, 23129 (2018). http://doi.org/10.1021/acs.jpcc.8b05344
Abstract: The electrodeposition of nickel nanostructures on glassy carbon was investigated in 1:2 choline chloride urea deep eutectic solvent (DES) containing different amounts of water. By combining electrochemical techniques, with ex situ field emission scanning electron microscopy, high-angle annular dark field scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy, the effect of water content on the electrochemical processes occurring during nickel deposition was better understood. At highly negative potentials and depending on water content, Ni growth is halted due to water splitting and formation of a mixed layer of Ni/NiOx(OH)(2(1-x)(ads)). Moreover, under certain conditions, the DES components can also be (electro)chemically reduced at the electrode surface, blocking further three-dimensional growth of the Ni NPs. Hence, a two-dimensional crystalline Ni-containing network can be formed in the interparticle region.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 27
DOI: 10.1021/acs.jpcc.8b05344
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“Films of filled single-wall carbon nanotubes as a new material for high-performance air-sustainable transparent conductive electrodes operating in a wide spectral range”. Tonkikh AA, Tsebro VI, Obraztsova EA, Rybkovskiy DV, Orekhov AS, Kondrashov II, Kauppinen EI, Chuvilin AL, Obraztsova ED, Nanoscale 11, 6755 (2019). http://doi.org/10.1039/C8NR10238D
Abstract: In this paper we show the advantages of transparent high conductive films based on filled single-wall carbon nanotubes. The nanotubes with internal channels filled with acceptor molecules (copper chloride or iodine) form networks demonstrating significantly improved characteristics. Due to the charge transfer between the nanotubes and filler, the doped-nanotube films exhibit a drop in electrical sheet resistance of an order of magnitude together with a noticeable increase of film transparency in the visible and near-infrared spectral range. The thermoelectric power measurements show a significant improvement of air-stability of the nanotube network in the course of the filling procedure. For the nanotube films with an initial transparency of 87% at 514 nm and electrical sheet resistance of 862 Ohm sq(-1) we observed an improvement of transparency up to 91% and a decrease of sheet resistance down to 98 Ohm sq(-1). The combination of the nanotube synthesis technique and molecules for encapsulation has been optimized for applications in optoelectronics.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 2
DOI: 10.1039/C8NR10238D
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“Investigating Reaction Intermediates during the Seedless Growth of Gold Nanostars Using Electron Tomography”. Choo P, Arenas-Esteban D, Jung I, Chang WJ, Weiss EA, Bals S, Odom TW, ACS nano 16, 4408 (2022). http://doi.org/10.1021/acsnano.1c10669
Abstract: Good’s buffers can act both as nucleating and shape- directing agents during the synthesis of anisotropic gold nanostars (AuNS). Although different Good’s buffers can produce AuNS shapes with branches that are oriented along specific crystallographic directions, the mechanism is not fully understood. This paper reports how an analysis of the intermediate structures during AuNS synthesis from HEPES, EPPS, and MOPS Good’s buffers can provide insight into the formation of seedless AuNS. Electron tomography of AuNS structures quenched at early times (minutes) was used to characterize the morphology of the incipient seeds, and later times were used to construct the growth maps. Through this approach, we identified how the crystallinity and shape of the first structures synthesized with different Good’s buffers determine the final AuNS morphologies.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 17.1
Times cited: 12
DOI: 10.1021/acsnano.1c10669
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“Gold and silver-catalyzed reductive amination of aromatic carboxylic acids to benzylic amines”. Coeck R, Meeprasert J, Li G, Altantzis T, Bals S, Pidko EA, De Vos DE, Acs Catalysis 11, 7672 (2021). http://doi.org/10.1021/ACSCATAL.1C01693
Abstract: The reductive amination of benzoic acid and its derivatives would be an effective addition to current synthesis methods for benzylamine. However, with current technology it is very difficult to keep the aromaticity intact when starting from benzoic acid, and salt wastes are often generated in the process. Here, we report a heterogeneous catalytic system for such a reductive amination, requiring solely H-2 and NH3 as the reactants. The Ag/TiO2 or Au/TiO2 catalysts can be used multiple times, and very little noble metal is required, only 0.025 mol % Au. The catalysts are bifunctional: the support catalyzes the dehydration of both the ammonium carboxylate to the amide and of the amide to the nitrile, while the sites at the metal-support interface promote the hydrogenation of the in situ generated nitrile. Yields of up to 92% benzylamine were obtained.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Impact Factor: 10.614
Times cited: 16
DOI: 10.1021/ACSCATAL.1C01693
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“Restructuring of titanium oxide overlayers over nickel nanoparticles during catalysis”. Monai M, Jenkinson K, Melcherts AEM, Louwen JN, Irmak EA, Van Aert S, Altantzis T, Vogt C, van der Stam W, Duchon T, Smid B, Groeneveld E, Berben P, Bals S, Weckhuysen BM, Science 380, 644 (2023). http://doi.org/10.1126/SCIENCE.ADF6984
Abstract: Reducible supports can affect the performance of metal catalysts by the formation of suboxide overlayers upon reduction, a process referred to as the strong metal-support interaction (SMSI). A combination of operando electron microscopy and vibrational spectroscopy revealed that thin TiOx overlayers formed on nickel/titanium dioxide catalysts during 400 degrees C reduction were completely removed under carbon dioxide hydrogenation conditions. Conversely, after 600 degrees C reduction, exposure to carbon dioxide hydrogenation reaction conditions led to only partial reexposure of nickel, forming interfacial sites in contact with TiOx and favoring carbon-carbon coupling by providing a carbon species reservoir. Our findings challenge the conventional understanding of SMSIs and call for more-detailed operando investigations of nanocatalysts at the single-particle level to revisit static models of structure-activity relationships.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Impact Factor: 56.9
Times cited: 29
DOI: 10.1126/SCIENCE.ADF6984
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“Nexus between land development and the value of ecosystem services in Ethiopia : a contingent valuation study”. Admasu WF, Van Passel S, Minale AS, Tsegaye EA, Nyssen J, Environment, development and sustainability , 1 (2023). http://doi.org/10.1007/S10668-022-02803-8
Abstract: In Ethiopia, the state owns all lands within the territory of the country. Cities are incorporating large parcels of land from their surrounding rural agricultural areas through land expropriation. However, these land developments do not consider the nonmarket value of ecosystem services (ES), which is causing a deterioration of the existing ES and reduction on the potential supply of ES from agricultural land. The aim of this study was to estimate the monetary value of nonmarketable ES from the agricultural land using a double-bounded dichotomous choice contingent valuation method. A survey of 524 smallholder farmers was conducted. In the survey, respondents were asked to state their willingness to pay for the improvement of some of the nonmarketable ES: erosion control, air and climate regulation, water regulation, and soil fertility. The estimation was carried out using a bivariate probit model. The results revealed that farmers are willing to pay on average 276 ETB (7.9 USD) per hectare per year for a period of 10 years. We found that individual characteristics such as age, family size, and a recent land expropriation experience adversely affect the willingness to pay by the farmers. On the other hand, individuals with higher income and larger land size are willing to pay more. In general, the study indicated that the nonmarket ES, which are affected by the land expropriation for urban expansion, are valuable for the farmers. Therefore, we recommend that the government consider the value of nonmarketable ES in its land use decisions and hence achieve sustainable land development.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 4.9
DOI: 10.1007/S10668-022-02803-8
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“Coupling a hydrological water quality model and an economic optimization model to set up a cost-effective emission reduction scenario for nitrogen”. Cools J, Broekx S, Vandenberghe V, Seuntjens P, ea, Environmental modelling and software 26, 44 (2011). http://doi.org/10.1016/J.ENVSOFT.2010.04.017
Abstract: A modelling approach is presented that determines the most cost-effective set of reduction measures to reach an in-stream concentration target. The framework is based on the coupling of two models: the hydrological water quality model SWAT and an economic optimization model (Environmental Costing Model, ECM). SWAT is used to determine the relationship between the modelled in-stream concentration at the river basin outlet and the associated emission reduction. The ECM is used to set up marginal abatement cost curves for nutrients and oxygen demanding substances. Results for nitrogen are presented for the Grote Nete river basin in Belgium for the year 2006. Results show that the good status for total nitrogen can be reached in the study area. The most cost-effective measures are more productive dairy cattle, implementing basic measures as defined in the WFD, winter cover crops, improved efficiency of WWTP, enhanced fodder efficiency for pigs, further treatment of industrial waste water and tuned fertilization. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.ENVSOFT.2010.04.017
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“Characterisation of concentrates of heavy mineral sands by micro-Raman spectrometry and CC-SEM/EDX with HCA”. Worobiec A, Stefaniak EA, Potgieter-Vermaak S, Sawlowicz Z, Spolnik Z, Van Grieken R, Applied geochemistry 22, 2078 (2007). http://doi.org/10.1016/J.APGEOCHEM.2007.05.003
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.APGEOCHEM.2007.05.003
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“Combined SEM/EDX and micro-Raman spectroscopy analysis of uranium minerals from a former uranium mine”. Stefaniak EA, Alsecz A, Frost R, Máthé, Z, Sajó, IE, Török S, Worobiec A, Van Grieken R, Journal of hazardous materials 168, 416 (2009). http://doi.org/10.1016/J.JHAZMAT.2009.02.057
Abstract: Samples of the secondary uranium minerals collected in the abandoned uranium mine at Pecs (Hungary) were investigated by two micro-techniques: scanning electron microscopy (SEM/EDX) and micro-Raman spectroscopy (MRS). They were applied to locate U-rich particles and identify the chemical form and oxidation state of the uranium compounds. The most abundant mineral was a K and/or Na uranyl sulphate (zippeite group). U(VI) was also present in the form showing intensive Raman scattering at 860 cm−1 which can be attributed to uranium trioxide. This research has shown the successful application of micro-Raman spectroscopy for the identification of uranyl mineral species on the level of individual particles.
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.JHAZMAT.2009.02.057
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“Comprehensive microanalytical study of welding aerosols with x-ray and Raman based methods”. Worobiec A, Stefaniak EA, Kiro S, Oprya M, Bekshaev A, Spolnik Z, Potgieter-Vermaak SS, Ennan A, Van Grieken R, X-ray spectrometry 36, 328 (2007). http://doi.org/10.1002/XRS.979
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.979
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“Molecular and elemental characterisation of mineral particles by means of parallel micro-Raman spectrometry and Scanning Electron Microscopy/Energy Dispersive X-ray Analysis”. Stefaniak EA, Worobiec A, Potgieter-Vermaak S, Alsecz A, Török S, Van Grieken R, Spectrochimica acta: part B : atomic spectroscopy 61, 824 (2006). http://doi.org/10.1016/J.SAB.2006.04.009
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.SAB.2006.04.009
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“Recognition of uranium oxides in soil particulate matter by means of ì-Raman spectrometry”. Stefaniak EA, Sajó, I, Alsecz A, Worobiec A, Máthé, Z, Török S, Van Grieken R, Journal of nuclear materials 381, 278 (2008). http://doi.org/10.1016/J.JNUCMAT.2008.08.036
Abstract: Soil samples from an abandoned uranium mine have been investigated in order to determine the molecular phases of uranium compounds. The experiments were carried out with soil particulate matter, collected randomly from the area of the formerly exploited ore. To select the particles rich with uranium, scanning electron microscopy with energy-dispersive X-ray attachment (SEM/EDX) was applied first. Afterwards, the particles were relocated and measured by l-Raman spectrometry (MRS). Residues of the main deposit, uraninite UO2, were detected, along with its alteration products. In terms of Raman scattering properties, uranium oxides are quite sensitive to the laser beam wavelength, which results in very specific features of their Raman spectra. In this paper the Raman spectra of uranium oxides of different origin and oxidation states, measured with 514 and 785 nm lasers, are also presented
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.JNUCMAT.2008.08.036
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“SnIV-containing layered double hydroxides as precursors for nano-sized ZnO/SnO2 photocatalysts”. Seftel EM, Popovici E, Mertens M, Stefaniak EA, Van Grieken R, Cool P, Vansant EF, Applied catalysis : B : environmental 84, 699 (2008). http://doi.org/10.1016/J.APCATB.2008.06.006
Abstract: Sn4+-containing LDH was prepared using the co-precipitation method at constant pH, and characterized using X-ray diffraction, UVvis diffuse reflectance spectroscopy and TG/DTG methods. The obtained product was further exposed to different thermal treatments in order to obtain nano-sized coupled ZnO/SnO2 systems with enhanced photocatalytic performances than the ones obtained by mixing the two semiconductor oxides. The formation of a well-defined ZnO/SnO2 system and the crystallite size, fully investigated using XRD, micro-Raman scattering and UVvis DR techniques, were found to be influenced by the nature of the precursors and the calcination temperature. The photocatalytic activity of the ZnO/SnO2 systems, evaluated for the photodegradation of methyl orange (MO) dye, was studied as a function of the initial pH, catalyst loading and the calcination temperature. The metal dispersion supplied by layered structures proved to be an advantage when preparing coupled ZnO/SnO2 systems, the photocatalytic activity being 2.3 times higher comparing with the physical mixtures performances. The maximum photocatalytic activity of the coupled ZnO/SnO2 system having a layered precursor was observed when using neutral pH, at a catalyst loading of 1 g/L calcined at 600 °C for 4 h.
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.APCATB.2008.06.006
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“Siberian Haze: complex study of aerosols in Siberia”. Koutsenogii PK, van Malderen H, Hoornaert S, Van Grieken R, Koutsenogii KP, Boufetov N, Makarov VI, Smoljakov BS, Nemirovski AM, Osipova LP, Krjukov JA, Ivakin EA, Posukh OL, Bronstein EL, Optics of the atmosphere and ocean 9, 712 (1996)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Non-invasive and non-destructive examination of artists’ pigments, paints and paintings by means of X-ray imaging methods”. Vanmeert F, De Meyer S, Gestels A, Clerici EA, Deleu N, Legrand S, Van Espen P, Van der Snickt G, Alfeld M, Dik J, Monico L, De Nolf W, Cotte M, Gonzalez V, Saverwyns S, Depuydt-Elbaum L, Janssens K page 317 (2022).
Abstract: Recent studies in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples and/or entire paintings from fifteenth to twentieth century artists are discussed. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging as well as with the combined use with X-ray diffraction (XRD). Microscopic XRF (μ-XRF) is a variant of the XRF method able to visualize the elemental distribution of key elements, mostly metals, on the scale from 1 μm to 100 μm present inside multi-layered micro samples taken from paintings. In the context of the characterization of artists’ pigments subjected to natural degradation, in many cases the use of methods limited to elemental analysis or imaging does not suffice to elucidate the chemical transformations that have taken place. However, at synchrotron facilities, combinations of μ-XRF with related methods such as μ-XAS (microscopic X-ray absorption spectroscopy) and μ-XRD have proven themselves to be very suitable for such studies. Since microscopic investigation of a relatively limited number of minute paint samples may not yield representative information about the complete artefact they were taken from, several methods for macroscopic, non-invasive imaging have recently been developed. Combined macroscopic XRF/XRD scanning is able to provide a fairly complete overview of the inorganic pigments employed to create a work of art, to answer questions about ongoing degradation phenomena and about its authenticity. As such these newly developed non-invasive and highly specific imaging methods are of interest for many cultural heritage stakeholders.
Keywords: H1 Book chapter; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS)
DOI: 10.1007/978-3-030-86865-9_11
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“Compositional correlation between pigments found in excavations and on human bones investigated with micro-raman spectrometry and scanning electron microscopy”. Vázquez C, Darchuk L, Stefaniak EA, Van Grieken R, Palacios OR page 13 (2011).
Keywords: H2 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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Kirschhock CEA, Liang D, Aerts A, Aerts CA, Kremer SPB, Jacobs PA, Van Tendeloo G, Martens JA (2004) On the TEM and AFM evidence of zeosil nanoslabs present during the synthesis of silicalite-1 : reply. Weinheim, 4562–4564
Keywords: L1 Letter to the editor; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
DOI: 10.1002/anie.200460541
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