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Author |
Borah, R. |
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Title |
Photoactive nanostructures : from single plasmonic nanoparticles to self-assembled films |
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Doctoral thesis |
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Year |
2022 |
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xxxiv, 220 p. |
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Doctoral thesis; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Photoactive nanoparticles and their light-driven applications have gained tremendous scientific attention towards remediation of the global environmental problems, meeting alternative energy demands, and other new technological discoveries. The research work presented in this dissertation includes a fundamental investigation of such nanoparticles to gain deeper insights that will ultimately benefit their application. In particular, the study of plasmonic metal nanoparticles and metal oxide nanoparticles for light driven applications is the major theme of this work. The investigation begins with isolated plasmonic Au and Ag nanoparticles, followed by a natural extension to nanoparticle clusters, and then further to nanoparticle films. Next, the application of such plasmonic nanoparticle films for gaseous phase sensing of volatile organic compounds is explored. Finally, the film formation of metal-oxide nanoparticles by self-assembly is investigated for the fabrication of photoactive functional interfaces. The fundamental theoretical investigation of the isolated plasmonic nanoparticles encompasses alloy and core-shell nanostructures of Au-Ag bimetallic compositions. First, the optical properties of bimetallic alloy and core-shell nanoparticles are compared for different structures such as nanospheres, nanotriangles and nanorods. Based on the optical properties, the photothermal properties of these nanostructures are also evaluated for relevant light-driven applications. Further, to bridge the gap between the theoretical and experimental optical properties of colloidal plasmonic nanoparticles, the effect of different statistical parameters pertaining to the particle size distribution is studied. Going from isolated nanoparticles to nanoparticle clusters, the changes in the optical properties of plasmonic nanoparticles when they form finite clusters is investigated. A strong effect of clustering on the absorption intensities of the nanoparticles and hence, on the photothermal properties is found. Next, for the study of plasmonic nanoparticle infinite arrays, Au and Ag nanoparticles films are experimentally obtained by the self-assembly at the air-ethylene glycol interface. Upon further validation of the computational models with the experimental optical properties of these films, the near-field and far-field optical response of the plasmonic nanoparticle arrays is investigated. An application of the self-assembled Au nanoparticle film is then demonstrated in the sensing of volatile organic compounds (VOCs). Finally, the focus is shifted from plasmonic nanoparticles to metal oxide nanoparticles for their self-assembly at the air-water interface to obtain self-assembled films. For this, the hydrophobic functionalization of four metal oxides nanoparticles namely, TiO2, ZnO, WO3 and CuO is investigated. The insights from this work is useful for the design and fabrication of functional nanoparticles and interfaces for light driven applications. |
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UA @ admin @ c:irua:189155 |
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7188 |
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Author |
Magalhães Cunha, S. |
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Title |
Wave-packet dynamics and electronic transport properties in 2D materials |
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Doctoral thesis |
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Year |
2022 |
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219 p. |
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Doctoral thesis; Condensed Matter Theory (CMT) |
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This piece of work is twofold. First, the time evolution of wave-packets in 2D systems is analyzed by the Split-Operator technique in three different scenarios: in multilayer phosphorene, the transient oscillations in the time-dependent average of position and momentum were observed due to the zitterbewegung effect, and the wave packet propagates non-uniformly along the space deforming itself into an elliptical shape. These results were corroborated by the Green’s function formalism except for large values of the wave-vector and long times; in 2D semiconductor quantum wires (QWs) with anisotropic effective masses and different angle orientations with respect to the anisotropic axis. We have shown that the greater this angle, the smaller is the energy levels spacing implying in an increase of the accessible electronic states. Additionally, for non-null magnetic field, the quantum Hall edge states are significantly affected by the edge orientation. In the anisotropic case damped oscillations in the average values of velocity in both x and y directions where obtained. Theses oscillations are originated by the QW geometry but also from subwavepackets with different momentum orientations, whereas for isotropic QWs the wavepacket disperses without splitting; in the third scenario the split-operator technique was used to study the Landau levels, the wave packet trajectories and velocities of electrons in graphene at low-energy regime described by a modified Dirac equation where the momentum-operator is written in a generalized form as result of applying the position-dependent translation operator formalism (PDTO). In the second part of this thesis, the electronic and tunneling properties of α − T3 lattices were studied. Electrons in these lattices behave analogous to integer-spin Dirac Fermions. The presence of a third atomic site in the unit cell leads to a flat band in the energy spectrum, providing unique electronic and tunneling properties. The presence of a super-periodic potential and the inclusion of symmetry-breaking terms results in deviations of the atomic equivalence between the atomic sites affecting the Dirac points and the band-gap. Small deviations in the equivalence between the atomic sites and the number of barriers change the transmission properties in these lattices. Additionally, new tunneling regions are possible by adjusting the symmetry between the atomic sites and affect the omnidirectional total transmission called super-Klein tunneling observed in these lattices. We compare those results to the tunneling probabilities through regions where the energy spectrum changes from linear with a middle flat band to a hyperbolic dispersion. |
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UA @ admin @ c:irua:189191 |
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7227 |
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Wang, L.; Miao, Q.; Niinemets, Ü.; Gielis, J.; Shi, P. |
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Title |
Quantifying the variation in the geometries of the outer rims of corolla tubes of Vinca major L |
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A1 Journal article |
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Year |
2022 |
Publication |
Plants |
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Volume |
11 |
Issue |
15 |
Pages |
1987-12 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Many geometries of plant organs can be described by the Gielis equation, a polar coordinate equation extended from the superellipse equation, . Here, r is the polar radius corresponding to the polar angle φ; m is a positive integer that determines the number of angles of the Gielis curve when φ ∈ [0 to 2π); and the rest of the symbols are parameters to be estimated. The pentagonal radial symmetry of calyxes and corolla tubes in top view is a common feature in the flowers of many eudicots. However, prior studies have not tested whether the Gielis equation can depict the shapes of corolla tubes. We sampled randomly 366 flowers of Vinca major L., among which 360 had five petals and pentagonal corolla tubes, and six had four petals and quadrangular corolla tubes. We extracted the planar coordinates of the outer rims of corolla tubes (in top view) (ORCTs), and then fitted the data with two simplified versions of the Gielis equation with k = 1 and m = 5: (Model 1), and (Model 2). The adjusted root mean square error (RMSEadj) was used to evaluate the goodness of fit of each model. In addition, to test whether ORCTs are radially symmetrical, we correlated the estimates of n2 and n3 in Model 1 on a log-log scale. The results validated the two simplified Gielis equations. The RMSEadj values for all corolla tubes were smaller than 0.05 for both models. The numerical values of n2 and n3 were demonstrated to be statistically equal based on the regression analysis, which suggested that the ORCTs of V. major are radially symmetrical. It suggests that Model 1 can be replaced by the simpler Model 2 for fitting the ORCT in this species. This work indicates that the pentagonal or quadrangular corolla tubes (in top view) can both be modeled by the Gielis equation and demonstrates that the pentagonal or quadrangular corolla tubes of plants tend to form radial symmetrical geometries during their development and growth. |
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000839115100001 |
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2022-08-01 |
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2223-7747 |
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OpenAccess |
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Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:189315 |
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7200 |
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Author |
Gielis, J.; Grigolia, R. |
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Title |
Lamé curves and Rvachev's R-functions |
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A3 Journal article |
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Year |
2022 |
Publication |
Sn – 1512-0066 |
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37 |
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1-4 |
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A3 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Gielis transformations are a generalization of Lame curves. To combine domains, we can make use of the natural alliance between Lame's work and Rvachev's R-functions. A logical next step is the extension to n-valued logic dening dierent partitions. |
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Most recent IF: NA |
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UA @ admin @ c:irua:189316 |
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7178 |
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Author |
Gielis, J.; Shi, P.; Caratelli, D. |
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Title |
Universal equations : a fresh perspective |
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A1 Journal article |
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Year |
2022 |
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Growth and Form |
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A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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A uniform description of natural shapes and phenomena is an important goal in science. Such description should check some basic principles, related to 1) the complexity of the model, 2) how well its fits real objects, phenomena and data, and 3) ia direct connection with optimization principles and the calculus of variations. In this article, we present nine principles, three for each group, and we compare some models with a claim to universality. It is also shown that Gielis Transformations and power laws have a common origin in conic sections |
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Most recent IF: NA |
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UA @ admin @ c:irua:189317 |
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7224 |
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Author |
Neven, L.; Barich, H.; Rutten, R.; De Wael, K. |
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Title |
Novel (photo)electrochemical analysis of aqueous industrial samples containing phenols |
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A1 Journal article |
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Year |
2022 |
Publication |
Microchemical journal |
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181 |
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107778-11 |
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A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Phenols are considered as toxic pollutants and their discharge into the environment by industries is regulated by a concentration limit. As these limits are in the low mg L−1 to µg L−1-range, sensitive methods are necessary to detect these phenols. Here, aqueous industrial phenolic samples throughout a cleaning process were analyzed by two novel electrochemical sensors. Both the photoelectrochemical (PEC) sensor and the square wave voltammetric (SWV) sensor could successfully follow the decrease of the concentration of phenols along the industrial cleaning process. The discharge sample (μg L−1) could only be analyzed by the PEC sensor and not by the SWV sensor, as the phenolic concentration was close to the LOD of the latter. With HPLC-diode array detector (DAD) measurements, classical phenols such as phenol (PHOH), hydroquinone, resorcinol and o-cresol could be identified in the industrial samples, and their presence could be linked to the electrochemical responses. At last, the performance of the PEC and SWV sensors were compared with commercial colorimetric and chemical oxygen demand (COD) test kits. This comparison demonstrated the high sensitivity of the PEC sensor in the μg L−1 concentrated phenolic samples. Together with the identification of the redox peaks through HPLC-DAD analysis, the SWV sensor can be a powerful tool in the qualitative analysis of mg L−1 concentrated phenolic samples due to its speed, simplicity and absence of laborious sample pre-treatment steps. |
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000837838400003 |
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2022-07-20 |
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0026-265x; 0026-265x |
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OpenAccess |
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UA @ admin @ c:irua:189428 |
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8906 |
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Friedrich, T.; Yu, C.-P.; Verbeek, J.; Pennycook, T.; Van Aert, S. |
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Phase retrieval from 4-dimensional electron diffraction datasets |
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P1 Proceeding |
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2021 |
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Proceedings
T2 – IEEE International Conference on Image Processing (ICIP), SEP 19-22, 2021, Electr. network |
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3453-3457 |
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P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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We present a computational imaging mode for large scale electron microscopy data, which retrieves a complex wave from noisy/sparse intensity recordings using a deep learning approach and subsequently reconstructs an image of the specimen from the Convolutional Neural Network (CNN) predicted exit waves. We demonstrate that an appropriate forward model in combination with open data frameworks can be used to generate large synthetic datasets for training. In combination with augmenting the data with Poisson noise corresponding to varying dose-values, we effectively eliminate overfitting issues. The U-NET[1] based architecture of the CNN is adapted to the task at hand and performs well while maintaining a relatively small size and fast performance. The validity of the approach is confirmed by comparing the reconstruction to well-established methods using simulated, as well as real electron microscopy data. The proposed method is shown to be effective particularly in the low dose range, evident by strong suppression of noise, good spatial resolution, and sensitivity to different atom types, enabling the simultaneous visualisation of light and heavy elements and making different atomic species distinguishable. Since the method acts on a very local scale and is comparatively fast it bears the potential to be used for near-real-time reconstruction during data acquisition. |
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000819455103114 |
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2021-08-23 |
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978-1-6654-4115-5 |
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UA library record; WoS full record; WoS citing articles |
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OpenAccess |
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Most recent IF: NA |
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UA @ admin @ c:irua:189462 |
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7089 |
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Maes, R.R.; Potters, G.; Fransen, E.; Van Schaeren, R.; Lenaerts, S. |
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Influence of adding low concentration of oxygenates in mineral diesel oil and biodiesel on the concentration of NO, NO₂ and particulate matter in the exhaust gas of a one-cylinder diesel generator |
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A1 Journal article |
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Year |
2022 |
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International journal of environmental research and public health |
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19 |
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13 |
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7637-18 |
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A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Air quality currently poses a major risk to human health worldwide. Transportation is one of the principal contributors to air pollution due to the quality of exhaust gases. For example, the widely used diesel fuel is a significant source of nitrogen oxides (NOx) and particulate matter (PM). To reduce the content NOx and PM, different oxygenated compounds were mixed into a mineral diesel available at the pump, and their effect on the composition of exhaust gas emissions was measured using a one-cylinder diesel generator. In this setup, adding methanol gave the best relative results. The addition of 2000 ppm of methanol decreased the content of NO by 56%, 2000 ppm of isopropanol decreased NO2 by 50%, and 2000 ppm ethanol decreased PM by 63%. An interesting question is whether it is possible to reduce the impact of hazardous components in the exhaust gas even more by adding oxygenates to biodiesels. In this article, alcohol is added to biodiesel in order to establish the impact on PM and NOx concentrations in the exhaust gases. Adding methanol, ethanol, and isopropanol at concentrations of 2000 ppm and 4000 ppm did not improve NOx emissions. The best results were using pure RME for a low NO content, pure diesel for a low NO2 content, and for PM there were no statistically significant differences. |
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000825645900001 |
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2022-06-23 |
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1661-7827; 1660-4601 |
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UA library record; WoS full record; WoS citing articles |
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OpenAccess |
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Most recent IF: NA |
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UA @ admin @ c:irua:189476 |
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7172 |
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Filez, M.; Feng, J.-Y.; Minjauw, M.M.; Solano, E.; Poonkottil, N.; Van Daele, M.; Ramachandran, R.K.; Li, C.; Bals, S.; Poelman, H.; Detavernier, C.; Dendooven, J.; Filez, M.; Minjauw, M.; Solano, E.; Poonkottil, N.; Li, C.; Bals, S.; Dendooven, J. |
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Shuffling atomic layer deposition gas sequences to modulate bimetallic thin films and nanoparticle properties |
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A1 Journal article |
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2022 |
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Chemistry of materials |
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A1 Journal article; Electron microscopy for materials research (EMAT) |
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Atomic layer deposition (ALD) typically employs metal precursors and co-reactant pulses to deposit thin films in a layer-by-layer fashion. While conventional ABAB-type ALD sequences implement only two functionalities, namely, a metal source and ligand exchange agent, additional functionalities have emerged, including etching and reduction agents. Herein, we construct gas-phase sequences-coined as ALD+-with complex-ities reaching beyond the classic ABAB-type ALD by freely combining multiple functionalities within irregular pulse schemes, e.g., ABCADC. The possibilities of such combinations are explored as a smart strategy to tailor bimetallic thin films and nanoparticle (NP) properties. By doing so, we demonstrate that bimetallic thin films can be tailored with target thickness and through the full compositional range, while the morphology can be flexibly modulated from thin films to NPs by shuI 1ing the pulse sequence. These complex pulse schemes are expected to be broadly applicable but are here explored for Pd-Ru bimetallic thin films and NPs. |
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000823205700001 |
Publication Date |
2022-06-29 |
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0897-4756; 1520-5002 |
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UA library record; WoS full record |
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2 |
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OpenAccess |
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This research was funded by the Research Foundation, Flanders (FWO) , and the Special Research Fund BOF of Ghent University (GOA 01G01019) . M.F. and M.M.M. acknowledge the FWO for a postdoctoral research fellowship (1280621N) . N.P. acknowledges the European Union's Horizon 2020 research and innovation program under the Marie Skiodowska-Curie grant agreement no. 765378. For the GISAXS measurements, the author s received funding from the European Community's Transnational Access Program CALIPSOplus. E.S. acknowledges the Spanish project RTI2018-093996-B-C32 MICINN/FEDER funds. Air Liquide is acknowledged for supporting this research. The authors acknowledge SOLEIL for the provision of synchrotron radiation facilities and would like to thank Dr. Alessandro Coati for assistance in using beamline SiXS. The GIWAXS experiments were performed at NCD-SWEET beamline at ALBA Synchrotron with the collaboration of ALBA staff . |
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UA @ admin @ c:irua:189541 |
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8928 |
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Poulain, R.; Lumbeeck, G.; Hunka, J.; Proost, J.; Savolainen, H.; Idrissi, H.; Schryvers, D.; Gauquelin, N.; Klein, A. |
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Electronic and chemical properties of nickel oxide thin films and the intrinsic defects compensation mechanism |
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A1 Journal article |
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Year |
2022 |
Publication |
ACS applied electronic materials |
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4 |
Issue |
6 |
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2718-2728 |
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A1 Journal article; Electron microscopy for materials research (EMAT) |
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Although largely studied, contradictory results on nickel oxide (NiO) properties can be found in the literature. We herein propose a comprehensive study that aims at leveling contradictions related to NiO materials with a focus on its conductivity, surface properties, and the intrinsic charge defects compensation mechanism with regards to the conditions preparation. The experiments were performed by in situ photo-electron spectroscopy, electron energy loss spectroscopy, and optical as well as electrical measurements on polycrystalline NiO thin films prepared under various preparation conditions by reactive sputtering. The results show that surface and bulk properties were strongly related to the deposition temperature with in particular the observation of Fermi level pinning, high work function, and unstable oxygen-rich grain boundaries for the thin films produced at room temperature but not at high temperature (>200 degrees C). Finally, this study provides substantial information about surface and bulk NiO properties enabling to unveil the origin of the high electrical conductivity of room temperature NiO thin films and also for supporting a general electronic charge compensation mechanism of intrinsic defects according to the deposition temperature. |
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000819431200001 |
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2022-06-07 |
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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 |
2637-6113 |
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 |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:189555 |
Serial |
7081 |
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| Permanent link to this record |
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Author |
Dobrota, A.S.; Vlahovic, J.; V. Skorodumova, N.; Pasti, I.A. |
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Title |
First-principles analysis of aluminium interaction with nitrogen-doped graphene nanoribbons – from adatom bonding to various |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Materials Today Communications |
Abbreviated Journal |
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Volume |
31 |
Issue |
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Pages |
103388-10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Enhancing aluminium interaction with graphene-based materials is of crucial importance for the development of Al-storage materials and novel functional materials via atomically precise doping. Here, DFT calculations are employed to investigate Al interactions with non-doped and N-doped graphene nanoribbons (GNRs) and address the impact of the edge sites and N-containing defects on the material's reactivity towards Al. The presence of edges does not influence the energetics of Al adsorption significantly (compared to pristine graphene sheet). On the other hand, N-doping of graphene nanoribbons is found to affect the adsorption energy of Al to an extent that strongly depends on the type of N-containing defect. The introduction of edge-NO group and doping with in -plane pyridinic N result in Al adsorption nearly twice as strong as on pristine graphene. Moreover, double n-type doping via N and Al significantly alters the electronic structure of Al,N-containing GNRs. Our results suggest that selectively doped GNRs with pyridinic N can have enhanced Al-storage capacity and could be potentially used for selective Al electrosorption and removal. On the other hand, Al,N-containing GNRs with pyridinic N could also be used in resistive sensors for mechanical deformation. Namely, strain along the longitudinal axis of these dual doped GNRs does not affect the binding of Al but tunes the bandgap and causes more than 700-fold change in the conductivity. Thus, careful defect engineering and selective doping of GNRs with N (and Al) could lead to novel multifunctional materials with exceptional properties. [GRAPHICS] |
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Wos |
000820987400002 |
Publication Date |
2022-03-15 |
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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 |
2352-4928 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:189563 |
Serial |
7163 |
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| Permanent link to this record |
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Author |
Faust, V.; Gruber, W.; Ganigue, R.; Vlaeminck, S.E.; Udert, K.M. |
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Title |
Nitrous oxide emissions and carbon footprint of decentralized urine fertilizer production by nitrification and distillation |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
ACS ES&T engineering |
Abbreviated Journal |
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Volume |
2 |
Issue |
9 |
Pages |
1745-1755 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Combining partial nitrification, granular activated carbon (GAC) filtration, and distillation is a well-studied approach to convert urine into a fertilizer. To evaluate the environmental sustainability of a technology, the operational carbon footprint and therefore nitrous oxide (N2O) emissions should be known, but N2O emissions from urine nitrification have not been assessed yet. Therefore, N2O emissions of a decentralized urine nitrification reactor were monitored for 1 month. During nitrification, 0.4-1.2% of the total nitrogen load was emitted as N2O-N with an average N2O emission factor (EFN2O) of 0.7%. Additional N2O was produced during anoxic storage between nitrification and GAC filtration with an estimated EFN2O of 0.8%, resulting in an EFN2O of 1.5% for the treatment chain. N2O emissions during nitrification can be mitigated by 60% by avoiding low dissolved oxygen or anoxic conditions and nitrite concentrations above 5 mg-N L-1. Minimizing the hydraulic retention time between nitrification and GAC filtration can reduce N2O formation during intermediate storage by 100%. Overall, the N2O emissions accounted for 45% of the operational carbon footprint of 14 kg-CO2,equiv kg-N-1 for urine fertilizer production. Using electricity from renewable sources and applying the proposed N2O mitigation strategies could potentially lower the carbon footprint by 85%. |
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Wos |
000835412700001 |
Publication Date |
2022-07-29 |
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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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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 |
OpenAccess |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:189599 |
Serial |
7182 |
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Author |
Ding, Y.; Maitra, S.; Arenas Esteban, D.; Bals, S.; Vrielinck, H.; Barakat, T.; Roy, S.; Van Tendeloo, G.; Liu, J.; Li, Y.; Vlad, A.; Su, B.-L. |
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Title |
Photochemical production of hydrogen peroxide by digging pro-superoxide radical carbon vacancies in carbon nitride |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Cell reports physical science |
Abbreviated Journal |
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Volume |
3 |
Issue |
5 |
Pages |
100874-17 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Artificial photosynthesis of H2O2, an environmentally friendly oxidant and a clean fuel, holds great promise. However, improving its efficiency and stability for industrial implementation remains highly challenging. Here, we report the visible-light H2O2 artificial photosynthesis by digging pro-superoxide radical carbon vacancies in three-dimensional hierarchical porous g-C3N4 through a simple hydrolysis-freeze-drying-thermal treatment. A significant electronic structure change is revealed upon the implantation of carbon vacancies, broadening visible-light absorption and facilitating the photogenerated charge separation. The strong electron affinity of the carbon vacancies promotes superoxide radical (O-center dot(2)-) formation, significantly boosting the H2O2 photocatalytic production. The developed photocatalyst shows an H2O2 evolution rate of 6287.5 mM g(-1) h(-1) under visible-light irradiation with a long cycling stability being the best-performing photocatalyst among all reported g-C3N4-based systems. Our work provides fundamental insight into highly active and stable photocatalysts with great potential for safe industrial H2O2 production. |
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Corporate Author |
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Wos |
000805830100006 |
Publication Date |
2022-04-28 |
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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 |
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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 |
12 |
Open Access |
OpenAccess |
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Notes |
Y.D. thanks the China Scholarship Council (201808310127) for financial support. This work is financially supported by the National Natural Science Foundation of China (U1663225) , Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52) of the Chinese Ministry of Education, Program of Introducing Talents of Discipline to Universities-Plan 111 (grant no. B20002) from the Ministry of Science and Technology and the Ministry of Education of China, and the National Key R&D Program of China (2016YFA0202602) . This research was also supported by the European Commission Interreg V France-Wallonie-Vlaanderen project “DepollutAir”. |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:189706 |
Serial |
7090 |
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| Permanent link to this record |
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Author |
Ninakanti, R.; Dingenen, F.; Borah, R.; Peeters, H.; Verbruggen, S.W. |
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Title |
Plasmonic hybrid nanostructures in photocatalysis : structures, mechanisms, and applications |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Topics in Current Chemistry |
Abbreviated Journal |
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Volume |
380 |
Issue |
5 |
Pages |
40-62 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
(Sun)Light is an abundantly available sustainable source of energy that has been used in catalyzing chemical reactions for several decades now. In particular, studies related to the interaction of light with plasmonic nanostructures have been receiving increased attention. These structures display the unique property of localized surface plasmon resonance, which converts light of a specific wavelength range into hot charge carriers, along with strong local electromagnetic fields, and/or heat, which may all enhance the reaction efficiency in their own way. These unique properties of plasmonic nanoparticles can be conveniently tuned by varying the metal type, size, shape, and dielectric environment, thus prompting a research focus on rationally designed plasmonic hybrid nanostructures. In this review, the term “hybrid” implies nanomaterials that consist of multiple plasmonic or non-plasmonic materials, forming complex configurations in the geometry and/or at the atomic level. We discuss the synthetic techniques and evolution of such hybrid plasmonic nanostructures giving rise to a wide variety of material and geometric configurations. Bimetallic alloys, which result in a new set of opto-physical parameters, are compared with core–shell configurations. For the latter, the use of metal, semiconductor, and polymer shells is reviewed. Also, more complex structures such as Janus and antenna reactor composites are discussed. This review further summarizes the studies exploiting plasmonic hybrids to elucidate the plasmonic-photocatalytic mechanism. Finally, we review the implementation of these plasmonic hybrids in different photocatalytic application domains such as H2 generation, CO2 reduction, water purification, air purification, and disinfection. |
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Wos |
000839670500009 |
Publication Date |
2022-08-11 |
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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 |
2364-8961 |
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 |
OpenAccess |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:189825 |
Serial |
7195 |
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Author |
De Meyer, S.; Vanmeert, F.; Janssens, K.; Storme, P. |
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Title |
A mobile scanner for xrpd-imaging of paintings in transmission and reflection geometry |
Type |
P1 Proceeding |
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Year |
2017 |
Publication |
ACTA ARTIS ACADEMICA 2017: PAINTING AS A STORY
T2 – 6th Interdisciplinary ALMA Conference, JUN 01-03, 2017, Brno, CZECH REPUBLIC |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
29-38 |
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Keywords |
P1 Proceeding; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
In this paper the possibilities and limitations of a non-invasive prototype of macroscopic X-ray powder diffraction scanning device employed in transmission and reflection mode are demonstrated. Contrarily to e.g. macroscopic X-ray fluorescence scanners, which gather information on the elemental level, the prototype instrument allows to obtain information on the crystallographic structure of the components. When applied to cultural heritage artefacts, it becomes possible to identify and localize crystalline pigments. Furthermore, it became clear that different information can be available depending on the geometry of the scanner components. In transmission mode information over the entire stratigraphy of the painting is gathered, which is useful to e.g. identify background substrates and major pigments. On the other hand, reflection-XRPD is a surface-sensitive technique and allows the identification of pigments and degradation products located on the surface. The data acquired during both experiments can be presented as two-dimensional distribution maps which show the spatial distribution of every identified pigment. The complementary nature of transmission and reflectionmode makes it possible to gain more insight into the stratigraphy of the painting which is valuable information for conservation and restoration scientists. |
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Wos |
000430517600002 |
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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 |
978-80-87108-75-8 |
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:189869 |
Serial |
7392 |
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Author |
Pacquets, L. |
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Title |
Towards stable Cu-Ag bimetallic nanoparticles to boost the electrocatalytic CO2 reduction |
Type |
Doctoral thesis |
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Year |
2022 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
xvi, 188 p. |
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Keywords |
Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
Ever since the industrial revolution, the emission of greenhouse gasses dramatically increased, resulting in high CO2 concentration in the atmosphere. The electrochemical conversion of CO2 to value added products, such as carbon monoxide, formic acid, methane, ethylene and ethanol is a very promising strategy to inhibit CO2 emissions. Nevertheless, at the moment, the electrochemical CO2 reduction (eCO2R) is not yet industrially viable, mainly due to the lack of good electrocatalysts. On the other hand, core-shell nanoparticles (NPs) have emerged over the last couple of years as promising candidates. It is believed that bimetallic enhancement effects are behind the improved performance of these core-shell NPs when compared to the individual metals. Although widely investigated, there are still some remaining issues and/or open questions. Indeed, the development of a robust and straightforward synthesis method along with fundamental insight into their resistance towards electrochemical stress remains absent. A good control over morphology, size and composition is key in determining which properties are beneficial for the eCO2R. Since these catalysts are designed to be implemented in electrolyzers, they have to maintain long-term performance. This makes the design of a reproducible method, unveiling structure-performance relationships the effect of electrochemical stress, a crucial aspect. Exploring and modifying existing synthesis methods, have led to the acquisition of a robust and reproducible synthesis method where thermal decomposition of the Cu core is combined with the galvanic replacement of Ag in organic solvents. The implementation of this method has led to the design of a wide variety of Cu-Ag bimetallic NPs and enabled to investigate their composition-selectivity profile. Introducing Ag on Cu suppressed hydrogen and increased the CO formation. CO production was boosted by using Cu@Ag core-shells and was promoted even more by changing the type of electrolyte. As these nanoparticles suffered from degradation, the 3D mapping of the structural changes of Cu@Ag core-shells under operating conditions led to the hypothesis of a two-step degradation mechanism where initially Cu leaching was observed with the subsequent sintering of the Ag shells. One approach to avoid this electrochemical degradation, investigated in this research, was the application of an ultrathin carbon layer to protect the active layer. This ultrathin carbon layer operated as a protective layer, suppressing hydrogen production and increasing the stability of the electrocatalyst. In conclusion, the product selectivity can be tuned by using different Cu-Ag bimetallic nanoparticles synthesized through a robust method. Their unique degradation pathway of Cu@Ag core-shell nanoparticles has led to the proposition of a more accurate stabilization strategy. These findings can contribute significantly in the quest for improved electrocatalysts for the eCO2R. |
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Additional Links |
UA library record |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:190236 |
Serial |
7221 |
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Author |
Dubrovinskaia, N.; Dubrovinsky, L.; Solopova, N.A.; Abakumov, A.; Turner, S.; Hanfland, M.; Bykova, E.; Bykov, M.; Prescher, C.; Prakapenka, V.B.; Petitgirard, S.; Chuvashova, I.; Gasharova, B.; Mathis, Y.-L.; Ershov, P.; Snigireva, I.; Snigirev, A. |
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Title |
Terapascal static pressure generation with ultrahigh yield strength nanodiamond |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Science Advances |
Abbreviated Journal |
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Volume |
2 |
Issue |
7 |
Pages |
e1600341-12 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Studies of materials' properties at high and ultrahigh pressures lead to discoveries of unique physical and chemical phenomena and a deeper understanding of matter. In high-pressure research, an achievable static pressure limit is imposed by the strength of available strong materials and design of high-pressure devices. Using a high-pressure and high-temperature technique, we synthesized optically transparent microballs of bulk nanocrystalline diamond, which were found to have an exceptional yield strength (similar to 460 GPa at a confining pressure of similar to 70 GPa) due to the unique microstructure of bulk nanocrystalline diamond. We used the nanodiamond balls in a double-stage diamond anvil cell high-pressure device that allowed us to generate static pressures beyond 1 TPa, as demonstrated by synchrotron x-ray diffraction. Outstanding mechanical properties (strain-dependent elasticity, very high hardness, and unprecedented yield strength) make the nanodiamond balls a unique device for ultrahigh static pressure generation. Structurally isotropic, homogeneous, and made of a low-Z material, they are promising in the field of x-ray optical applications. |
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Wos |
000381805300029 |
Publication Date |
2016-07-21 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
2375-2548 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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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:190527 |
Serial |
8647 |
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Author |
Alexiades, V.; Autrique, D. |
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Title |
Enthalpy model for heating, melting, and vaporization in laser ablation |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Electronic journal of differential equations |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
1-13 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Laser ablation is used in a growing number of applications in various areas including medicine, archaeology, chemistry, environmental and materials sciences. In this work the heat transfer and phase change phenomena during nanosecond laser ablation of a copper (Cu) target in a helium (He) background gas at atmospheric pressure are presented. An enthalpy model is outlined, which accounts for heating, melting, and vaporization of the target. As far as we know, this is the first model that connects the thermodynamics and underlying kinetics of this challenging phase change problem in a selfconsistent way. |
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Wos |
000455668500001 |
Publication Date |
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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 |
1072-6691 |
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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no |
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Call Number |
UA @ admin @ c:irua:190550 |
Serial |
7925 |
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Author |
Vanmeert, F.; De Meyer, S.; Gestels, A.; Clerici, E.A.; 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. |
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Title |
Non-invasive and non-destructive examination of artists’ pigments, paints and paintings by means of X-ray imaging methods |
Type |
H1 Book chapter |
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Year |
2022 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
317-357 |
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Keywords |
H1 Book chapter; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS) |
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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. |
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Wos |
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Publication Date |
2022-09-08 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
978-3-030-86864-2 |
Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:190777 |
Serial |
7183 |
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Author |
Klaassen, L.; van der Snickt, G.; Legrand, S.; Higgitt, C.; Spring, M.; Vanmeert, F.; Rosi, F.; Brunetti, B.G.; Postec, M.; Janssens, K. |
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Title |
Characterization and removal of a disfiguring oxalate crust on a large altarpiece by Hans Memling |
Type |
H1 Book chapter |
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Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
263-282
T2 - Metal soaps in art / Casadio, F. [edi |
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Keywords |
H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
During the conservation treatment of Memling’s Christ with Singing and Music-making Angels, three panel paintings that are among the most monumental works in early Netherlandish art, the conservators came across insoluble surface layers containing calcium oxalates. A very thin and irregular layer of this type, hardly visible to the naked eye, was spread across the surface of all three panels. A much thicker layer forming an opaque and highly disfiguring crust that obscured the composition (Figs. 15.1 and 15.7) was locally present on areas of dark copper-containing paint, where multiple layers of old discolored coatings and accretions remained in place before the most recent cleaning. This article describes the application of a wide range of analytical techniques in order to fully understand the stratigraphy and composition of the crusts on the Memling paintings. FTIR spectroscopy in transmission and reflection mode, micro-ATR-FTIR imaging and macro-rFTIR scanning, SEM-EDX, mobile XRD, and SR-μXRD showed that the crusts contained two related Ca-based oxalate salts, whewellite and weddellite, and were separated from the original paint surface by varnish, indicating that they did not originate from degradation of the original paint but from a combination of microbial action and a thick accumulation of dirt. Supported by the results from these different analytical techniques, which when used together proved to be very effective in providing complementary information that addressed this specific conservation problem, and aided by the presence of the intermediate varnish layer(s), the conservators were able to remove most of the crusts with spectacular results. |
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Publication Date |
2019-03-23 |
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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 |
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ISBN |
978-3-319-90616-4 |
Additional Links |
UA library record |
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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:190778 |
Serial |
7609 |
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| Permanent link to this record |
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Author |
Monico, L.; Hendriks, E.; Geldof, M.; Miliani, C.; Janssens, K.; Brunetti, B.G.; Cotte, M.; Vanmeert, F.; Chieli, A.; Van der Snickt, G.; Romani, A.; Melo, M.J. |
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Title |
Chemical alteration and colour changes in the Amsterdam sunflowers |
Type |
H1 Book chapter |
| |
Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
125-158
T2 - Van Gogh’s Sunflowers illuminated – a |
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Keywords |
H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
This chapter provides a description of colour changes in the Amsterdam Sunflowers due to chemical alteration of pigments, with a focus on geranium lakes and chrome yellows. The brilliant and forceful colours of these and other late nineteenth-century synthetic materials offered artists such as Vincent van Gogh new means of artistic expression that exploited a range of contrasting hues and tints. However, geranium lakes have a strong tendency to fade and chrome yellows to darken under the influence of light. Van Gogh, like other artists of his day, was aware of this drawback, yet he continued to favour the use of both pigments up until his death in July 1890 due to the unparalleled effects they gave. In April 1888, Vincent wrote to his brother Theo: Van Gogh's use of unstable colours opens a series of questions regarding the extent to which colour change affects the way his paintings look today, as discussed here in relation to the Amsterdam Sunflowers. Furthermore, given the frequency with which geranium lakes and chrome yellows occur in Van Gogh's paintings of the period 1888–90 and the predominance of chrome yellows in Sunflowers, it becomes important to understand the factors that can drive these processes of deterioration in order to develop appropriate strategies for conserving the artist's works. |
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Wos |
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Publication Date |
2020-11-25 |
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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 |
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ISBN |
978-94-6372-532-3 |
Additional Links |
UA library record |
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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:190779 |
Serial |
7640 |
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| Permanent link to this record |
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Author |
Hendriks, E.; Geldof, M.; van den Berg, K.J.; Monico, L.; Miliani, C.; Moretti, P.; Iwanicka, M.; Targowski, P.; Megens, L.; de Groot, S.; van Keulen, H.; Janssens, K.; Vanmeert, F.; van der Snickt, G. |
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Title |
Conservation of the Amsterdam sunflowers : from past to future |
Type |
H1 Book chapter |
| |
Year |
2019 |
Publication |
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Abbreviated Journal |
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| |
Volume |
|
Issue |
|
Pages |
175-205
T2 - Van Gogh’s Sunflowers illuminated – a |
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Keywords |
H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
This chapter lays out a conservation timeline, from past to future, for the Amsterdam version of Van Gogh's Sunflowers. It starts by considering the restoration history of the painting in order to assess its current physical state, and looks ahead to formulate an appropriate strategy for future conservation treatment and display. Due attention is paid to the two recorded episodes of restoration performed in 1927 and 1961 by the Dutch restorer, Jan Cornelis Traas. Based on physical and chemical investigation of Sunflowers we attempt to reconstruct what these former treatments (which are barely documented) entailed and consider the repercussions for the present condition of the painting. The former interventions by Traas also serve as a benchmark to reflect on current choices made, highlighting the extent to which ideas and methodologies have continued to evolve over the past century as conservation has moved further away from being a singularly craft-based activity to become an established historical and scientific discipline underpinned by ethical guidelines. Jan Cornelis Traas (1898–1984) As mentioned, the two main recorded interventions to the Amsterdam Sunflowers may be associated with the Dutch restorer, Jan Cornelis Traas, who treated the picture in 1927, close to the start of his career, and again in 1961, shortly before he retired. Traas was the first restorer to be appointed at the Mauritshuis in The Hague where he worked from 1931 to 1962 and treated hundreds of paintings, including iconic masterpieces such as Girl with a Pearl Earring by Johannes Vermeer. Yet despite the magnitude and importance of his restoration oeuvre, J.C. Traas (as he is usually referred to in surviving documents), has remained somewhat obscure. He is shown here in the only known surviving photograph of him at work, shortly before he retired (fig. 7.1). Unlike his illustrious contemporaries, A. Martin de Wild (1899–1969) and Helmut Ruhemann (1891–1973), for example, Traas did not publish anything, he appears to have kept no records of his work and no personal archive is known. However, the study of some newly discovered historical documents, combined with physical examination of Sunflowers and a large number of other works he treated, allows us to recover an idea of his working practices and approaches viewed within the context of his day. |
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Wos |
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Publication Date |
2020-11-25 |
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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 |
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ISBN |
978-94-6372-532-3 |
Additional Links |
UA library record |
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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:190780 |
Serial |
7727 |
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| Permanent link to this record |
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Author |
Geldof, M.; Monico, L.; Johnson, D.H.; Miliani, C.; Romani, A.; Grazia, C.; Buti, D.; Brunetti, B.G.; Janssens, K.; Van der Snickt, G.; Vanmeert, F. |
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Title |
Methods and materials of the Amsterdam sunflowers |
Type |
H1 Book chapter |
| |
Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
|
Issue |
|
Pages |
85-123
T2 - Van Gogh’s Sunflowers illuminated – ar |
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Keywords |
H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
This chapter explains the materials and techniques employed in the Amsterdam Sunflowers, enabling a comparison with the London version described in chapter 3. Building upon the 2016 article published in the National Gallery Technical Bulletin, it incorporates the latest findings gained by computer-assisted methods used to characterize the canvas support, as well as in-situ campaigns of non-invasive investigation together with further analysis of microscopic paint samples. The chapter sequence follows the steps in Van Gogh's working practice. Starting with the canvas, automated analysis of the weave enables the provenance of the canvas to be traced back to a particular roll of linen ordered by Van Gogh. Combining technical evidence with knowledge of historical manufacturing techniques further allows us to reconstruct the way in which Van Gogh divided his canvas roll into pieces used for Sunflowers and other paintings. We go on to consider how, with the original painting at hand, he used charcoal to transfer the motif of the London Sunflowers onto his blank canvas. Despite careful planning of the composition, an adjustment was required late in the working process, when Van Gogh added a painted wooden strip to extend the background above the flower at the top edge of the canvas. The artist's process of working up the composition in paint is described, paying special attention to his use of colour. The pigments and pigment mixtures used in the Amsterdam Sunflowers have been comprehensively mapped and are compared with the London picture, with discussion of some similarities and differences that account for the distinctive colour scheme of each painting. This understanding of colour application in the Amsterdam Sunflowers lays the foundation for subsequent chapters that will go on to consider the impact of light-induced colour changes that have taken place over time, and the related need to define appropriate lighting guidelines for the future safe preservation of this painting and others made with similar materials (chapters 5 and 7). |
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Wos |
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Publication Date |
2020-11-25 |
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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 |
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ISBN |
978-94-6372-532-3 |
Additional Links |
UA library record |
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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:190781 |
Serial |
8223 |
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| Permanent link to this record |
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Author |
Janssens, K.; Alfeld, M.; Van der Snickt, G.; De Nolf, W.; Vanmeert, F.; Monico, L.; Legrand, S.; Dik, J.; Cotte, M.; Falkenberg, G.; van der Loeff, L.; Leeuwestein, M.; Hendriks, E. |
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Title |
Examination of Vincent van Gogh's paintings and pigments by means of state-of-the-art analytical methods |
Type |
H2 Book chapter |
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Year |
2014 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
373-403
T2 - Science and art : the painted surface |
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Keywords |
H2 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Recent studies in which X-ray beams of macroscopic to (sub) microscopic dimensions were used for non-destructive analysis and characterization of pigments, paint micro samples and/or entire paintings by Vincent van Gogh are concisely reviewed. 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 of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). Microscopic and macroscopic XRF are variants of the method that are well suited to visualize the elemental distribution of key elements, mostly metals, present in paint multi layers, either on the length scale from 1–100 μm inside micro samples taken from paintings or on the 1–100 cm length scale when the (subsurface) distribution of specific pigments in entire paintings is concerned. In the context of the characterization of van Gogh's pigments subject to natural degradation, the use of methods limited to elemental analysis or imaging usually is not sufficient to elucidate the chemical transformations that have taken place. However, at synchrotron facilities, combinations of μ-XRF with related methods such as μ-XAS and μ-XRD have proven themselves to be very suitable for such studies. Their use is often combined with microscopic Fourier transform infra-red (μ-FTIR) spectroscopy since this method delivers complementary information at more or less the same length scale as the X-ray microprobe techniques. Also in the context of macroscopic imaging of works of art, the complementary use of X-ray based and infra-red based imaging appears very promising; some recent developments are discussed. |
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Wos |
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Publication Date |
2020-02-24 |
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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 |
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ISBN |
978-1-84973-818-7 |
Additional Links |
UA library record |
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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:190782 |
Serial |
7943 |
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| Permanent link to this record |
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Author |
Vanmeert, F.; Van der Snickt, G.; Legrand, S.; Janssens, K. |
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Title |
Velázquez? A portrait of Pope Innocent X : an X-ray imaging investigation (II) |
Type |
H3 Book chapter |
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Year |
2019 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
132-141
T2 - Velázquez : Anregungen, Vorschläge, L |
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Keywords |
H3 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Encompassing a broad spectrum of methodological approaches and aims, the scholars contributing to this volume offer renewed perspectives on the multifaceted oeuvre of Diego Velázquez. The seventeenth-century artist’s exceptional religious works as well as his numerous portraits are examined within the social and historical context of Velázquez’s milieu which included both the Spanish court as well as circles comprising important intellectual figures of his time. Following a close investigation of his works, which also includes the results of recent technological examinations on his paintings, the contributors to this volume offer new, exciting findings and discussions on the inspirations, sources and possible intentions of Velázquez. |
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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 |
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ISBN |
978-3-99020-155-8 |
Additional Links |
UA library record |
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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:190783 |
Serial |
8736 |
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| Permanent link to this record |
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Author |
Dasgupta, N.; Borah, R.; Mishra, P.; Gupta, A.K.; Chhabra, R.P. |
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Title |
Combined effects of blockage and yield stress on drag and heat transfer from an in-line array of three spheres |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Journal of dispersion science and technology |
Abbreviated Journal |
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Volume |
40 |
Issue |
6 |
Pages |
855-873 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
This work reports results on the drag and heat transfer from an in-line array of three isothermal spheres falling in a cylindrical confinement filled with Bingham plastic fluids. The effects of dimensionless parameters, such as the Reynolds number (1 ≤ Re ≤ 100), Prandtl number (1 ≤ Pr ≤ 100), Bingham number (0 ≤ Bn ≤ 100), blockage ratio (2 ≤ β ≤ 4) and sphere-to-sphere distance (1.5 ≤ t ≤ 6) have been elucidated. The flow and heat transfer characteristics were analysed in terms of yielded/unyielded regions, streamline and isotherm contours, drag coefficient, pressure coefficient, and local and average Nusselt number. Broadly, the drag coefficient shows a positive dependence on Bn and sphere-to-sphere distance (t) while it exhibits an inverse dependence on Re and β. On the other hand, the Nusselt number shows a positive dependence on Re, Pr, Bn and β; and a complex dependence on t for each sphere. Simple predictive expressions for the average Nusselt number for each sphere are formulated, thereby enabling its prediction in a new application. |
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Wos |
000467844200010 |
Publication Date |
2018-12-01 |
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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 |
0193-2691 |
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:190865 |
Serial |
7680 |
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| Permanent link to this record |
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Author |
Faust, V.; van Alen, T.A.; Op den Camp, H.J.M.; Vlaeminck, S.E.; Ganigué, R.; Boon, N.; Udert, K.M. |
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Title |
Ammonia oxidation by novel “Candidatus Nitrosacidococcus urinae” is sensitive to process disturbances at low pH and to iron limitation at neutral pH |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Water Research X |
Abbreviated Journal |
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Volume |
17 |
Issue |
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Pages |
100157-11 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Acid-tolerant ammonia-oxidizing bacteria (AOB) can open the door to new applications, such as partial nitritation at low pH. However, they can also be problematic because chemical nitrite oxidation occurs at low pH, leading to the release of harmful nitrogen oxide gases. In this publication, the role of acid-tolerant AOB in urine treatment was explored. On the one hand, the technical feasibility of ammonia oxidation under acidic conditions for source-separated urine with total nitrogen concentrations up to 3.5 g-N L−1 was investigated. On the other hand, the abundance and growth of acid-tolerant AOB at more neutral pH was explored. Under acidic conditions (pH of 5), ammonia oxidation rates of 500 mg-N L−1 d−1 and 10 g-N g-VSS-1 d-1 were observed, despite high concentrations of 15 mg-N L−1 of the AOB-inhibiting compound nitrous acid and low concentration of 0.04 mg-N L−1 of the substrate ammonia. However, ammonia oxidation under acidic conditions was very sensitive to process disturbances. Even short periods of less than 12 h without oxygen or without influent resulted in a complete cessation of ammonia oxidation with a recovery time of up to two months, which is a problem for low maintenance applications such as decentralized treatment. Furthermore, undesirable nitrogen losses of about 10% were observed. Under acidic conditions, a novel AOB strain was enriched with a relative abundance of up to 80%, for which the name “Candidatus (Ca.) Nitrosacidococcus urinae” is proposed. While Nitrosacidococcus members were present only to a small extent (0.004%) in urine nitrification reactors operated at pH values between 5.8 and 7, acid-tolerant AOB were always enriched during long periods without influent, resulting in an uncontrolled drop in pH to as low as 2.5. Long-term experiments at different pH values showed that the activity of “Ca. Nitrosacidococcus urinae” decreased strongly at a pH of 7, where they were also outcompeted by the acid-sensitive AOB Nitrosomonas halophila. The experiment results showed that the decreased activity of “Ca. Nitrosacidococcus urinae” correlated with the limited availability of dissolved iron at neutral pH. |
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Wos |
000877925500001 |
Publication Date |
2022-10-04 |
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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 |
2589-9147 |
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 |
OpenAccess |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:190944 |
Serial |
7124 |
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| Permanent link to this record |
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Author |
Oliveira, M.C. |
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Title |
Influence of phase-separated domains on the permeability of oxidized lipid membranes |
Type |
Doctoral thesis |
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Year |
2022 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
151 p. |
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Keywords |
Doctoral thesis; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Biological membranes are under constant attack of reactive oxygen and nitrogen species (RONS), which may lead to a complex mixture of nitro-oxidized lipids that are responsible for structural and dynamic changes on the membrane. Because of that, nitro-oxidized lipids are also associated with several tumors and inflammatory and neurodegenerative diseases. Moreover, lipid oxidation may induce membrane phase-separated domains, which also drastically affect the membrane function. Evidence suggests that domain interfaces are “hot spots” for pore formation, but the underlying mechanisms remain elusive. There is an urgent need for an improved understanding of oxidation-induced phase separation on membrane properties. Likewise, the molecular structure at domain interfaces still needs to be elucidated. To evaluate the effect of lipid nitro-oxidation on the permeability of single-phase (homogeneous) and phase-separated (heterogeneous) phospholipid bilayers (PLBs), we performed atomistic molecular dynamics (MD) simulations using: (1) single-phase PLBs composed of several isomers of nitrated and/or oxidized lipids; (2) phase-separated PLBs composed of coexisting liquid ordered (Lo) and liquid disordered (Ld) domains, where the Ld domain is composed of non-oxidized and/or oxidized lipids. Our results show that nitrated lipids increase the membrane permeability of single-phase PLBs by three-fold compared to oxidized lipids. In addition, we show that oxidized lipids in the presence of nitrated lipids decrease the membrane permeability, suggesting an interaction between nitrated and oxidized lipids. Overall, the permeability of single-phase and phase-separated PLBs was comparable, and the presence of oxidized lipids increases the membrane permeability only in single-phase PLBs. Despite the latter, the presence of only 1.5% of lipid aldehydes at the Lo/Ld domain interfaces of phase-separated PLBs was able to increase the membrane permeability. In consequence of this, we also performed coarse-grained MD simulations to evaluate whether lipid aldehydes have a preference to accumulate at the interface between Lo/Ld domains. Our results show that lipid aldehydes derived from mono-unsaturated lipids accumulate at the interface, but those derived from poly-unsaturated lipids remain in the Ld domain. This study is of interest for photodynamic therapy and plasma medicine for cancer treatment, to understand the effects caused by RONS in cell membranes. |
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Additional Links |
UA library record |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:191039 |
Serial |
7173 |
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| Permanent link to this record |
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Author |
Menezes, R.M.; Sardella, E.; Cabral, L.R.E.; de Souza Silva, C.C. |
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Title |
Self-assembled vortex crystals induced by inhomogeneous magnetic textures |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
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Volume |
31 |
Issue |
17 |
Pages |
175402 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate the self-assembly of vortices in a type-II superconducting disk subjected to highly nonuniform confining potentials produced by inhomogeneous magnetic textures. Using a series of numerical experiments performed within the Ginzburg–Landau theory, we show that vortices can arrange spontaneously in highly nonuniform, defect-free crystals, reminiscent of conformal lattices, even though the strict conditions for the conformal crystal are not fulfilled. These results contradict continuum-limit theory, which predicts that the order of a nonuniform crystal is unavoidably frustrated by the presence of topological defects. By testing different cooling routes of the superconductor, we observed several different self-assembled configurations, each of which corresponding to one in a set of allowed conformal transformations, which depends on the magnetic and thermal histories of the system. |
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Place of Publication |
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Editor |
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Wos |
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Publication Date |
2019-01-30 |
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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 |
0953-8984 |
ISBN |
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Additional Links |
UA library record |
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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:191094 |
Serial |
8511 |
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Author |
Joosten, F.; Parrilla, M.; van Nuijs, A.L.N.; Ozoemena, K.Id; De Wael, K. |
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Title |
Electrochemical detection of illicit drugs in oral fluid : potential for forensic drug testing |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Electrochimica acta |
Abbreviated Journal |
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Volume |
2022 |
Issue |
436 |
Pages |
141309-141315 |
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Keywords |
A1 Journal article; Pharmacology. Therapy; Engineering sciences. Technology; Toxicological Centre; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
Illicit drugs continue to pose a serious threat to society and public health. Drug (ab)use is linked to organised crime and violence. Therefore, to fight the so-called war on drugs, police and law enforcement agencies need to be equipped with accurate and efficient sensors for the detection of illicit drugs and drug use. Even though colour tests (for powders) and lateral flow immunoassays (for biological samples) lack accuracy, they are relied upon for fast and easy on-site detection. Alternatively, in recent years, there has been an increasing interest in electrochemical sensors as a promising technique for the rapid and accurate on-site detection of illicit drugs. While a myriad of literature exists on the use of electrochemical sensors for drug powder analysis, literature on their use for the detection of drug use in biological samples is scarce. To this end, this review presents an overview of strategies for the electrochemical detection of illicit drugs in oral fluid. First, pharmacokinetics of drugs in oral fluid and the legal limit dilemma regarding the analytical cut-offs for roadside drug detection tests are elaborated to present the reader with the background knowledge required to develop such a test. Subsequently, an overview of electrochemical strategies developed for the detection of illicit drugs in oral fluid is given. Importantly, key challenges to address in the development of roadside tests are highlighted to improve the design of the next electrochemical devices and to bring them to the field. Overall, electrochemical sensors for illicit drugs detection in oral fluid show promise to disrupt current strategies for roadside testing. |
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Place of Publication |
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Wos |
000882442300001 |
Publication Date |
2022-10-13 |
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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 |
0013-4686 |
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 |
OpenAccess |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:191107 |
Serial |
8855 |
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| Permanent link to this record |
