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Author Al-Emam, E.; Motawea, A.G.; Caen, J.; Janssens, K.
Title Soot removal from ancient Egyptian complex painted surfaces using a double network gel : empirical tests on the ceiling of the sanctuary of Osiris in the temple of Seti I-Abydos Type A1 Journal article
Year 2021 Publication Heritage science Abbreviated Journal
Volume 9 Issue 1 Pages 1-10
Keywords A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
Abstract (down) In this study, we evaluated the ease of removal of soot layers from ancient wall paintings by employing double network gels as a controllable and safe cleaning method. The ceiling of the temple of Seti I (Abydos, Egypt) is covered with thick layers of soot; this is especially the case in the sanctuary of Osiris. These layers may have been accumulated during the occupation of the temple by Christians, fleeing the Romans in the first centuries A.D. Soot particulates are one of the most common deposits to be removed during conservation-restoration activities of ancient Egyptian wall paintings. They usually mask the painted reliefs and reduce the permeability of the painted surface. A Polyvinyl alcohol-borax/agarose (PVA-B/AG) double network gel was selected for this task since its properties were expected to be compatible with the cleaning treatment requirements. The gel is characterized by its flexibility, permitting to take the shape of the reliefs, while also having self-healing properties, featuring shape stability and an appropriate capacity to retain liquid. The gel was loaded with several cleaning reagents that proved to be effective for soot removal. Soot removal tests were conducted with these gel composites. The cleaned surfaces were evaluated with the naked eye, a digital microscope, and color measurements in order to select the best gel composite. The gel composite, loaded with a solution of 5% ammonia, 0.3% ammonium carbonate, and 0.3% EDTA yielded the most satisfactory results and allowed to safely remove a crust of thick soot layers from the surface. Thus, during the final phase of the study, it was used successfully to clean a larger area of the ceiling.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000604977300001 Publication Date 2021-01-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-7445 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:174948 Serial 8557
Permanent link to this record
 

 
Author Carballa, M.; Smits, M.; Etchebehere, C.; Boon, N.; Verstraete, W.
Title Correlations between molecular and operational parameters in continuous lab-scale anaerobic reactors Type A1 Journal article
Year 2011 Publication Applied microbiology and biotechnology Abbreviated Journal
Volume 89 Issue 2 Pages 303-314
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this study, the microbial community characteristics in continuous lab-scale anaerobic reactors were correlated to reactor functionality using the microbial resource management (MRM) approach. Two molecular techniques, denaturing gradient gel electrophoresis (DGGE) and terminal-restriction fragment length polymorphism (T-RFLP), were applied to analyze the bacterial and archaeal communities, and the results obtained have been compared. Clustering analyses showed a similar discrimination of samples with DGGE and T-RFLP data, with a clear separation between the meso- and thermophilic communities. Both techniques indicate that bacterial and mesophilic communities were richer and more even than archaeal and thermophilic communities, respectively. Remarkably, the community composition was highly dynamic for both Bacteria and Archaea, with a rate of change between 30% and 75% per 18 days, also in stable performing periods. A hypothesis to explain the latter in the context of the converging metabolism in anaerobic processes is proposed. Finally, a more even and diverse bacterial community was found to be statistically representative for a well-functioning reactor as evidenced by a low Ripley index and high biogas production.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000285872500008 Publication Date 2010-09-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0175-7598; 1432-0614 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:85202 Serial 7736
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Author Hu, J.; Zhao, J.; Wang, D.; Li, X.; Zhang, D.; Xu, Q.; Peng, L.; Yang, Q.; Zeng, G.
Title Effect of diclofenac on the production of volatile fatty acids from anaerobic fermentation of waste activated sludge Type A1 Journal article
Year 2018 Publication Bioresource technology Abbreviated Journal
Volume 254 Issue Pages 7-15
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this study, the impact of diclofenac (DCF), an antiinflammatory drug being extensively used in human health care and veterinary treatment, on the production of volatile fatty acids (VFAs) from anaerobic fermentation of waste activated sludge (WAS) was investigated for the first time. Experimental results showed that when DCF concentration increased from 2.5 to 25 mg/kg total suspended solid (TSS), the maximum production of VFAs increased from 599 to 1113 mg COD/L, but further increase of DCF to 47.5 mg/kg TSS decreased VFAs yield to 896 mg COD/L. The mechanism investigation revealed that DCF had no effect on the hydrolysis process, promoted the process of acidogenesis, acetogenesis, and homoacetogenesis, but severely inhibited methanogenesis, leading to the accumulation of VFAs. Microbial community analysis showed that the addition of DCF could promote the relative abundance of VFAs (especially acetic acid) producers, which was well consistent with the results obtained above.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000426436100002 Publication Date 2018-01-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-8524 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:149849 Serial 7837
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Author Velimirovic, M.; Carniato, L.; Simons, Q.; Schoups, G.; Seuntjens, P.; Bastiaens, L.
Title Corrosion rate estimations of microscale zerovalent iron particles via direct hydrogen production measurements Type A1 Journal article
Year 2014 Publication Journal of hazardous materials Abbreviated Journal
Volume 270 Issue Pages 18-26
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this study, the aging behavior of microscale zerovalent iron (mZVI) particles was investigated by quantifying the hydrogen gas generated by anaerobic mZVI corrosion in batch degradation experiments. Granular iron and nanoscale zerovalent iron (nZVI) particles were included in this study as controls. Firstly, experiments in liquid medium (without aquifer material) were performed and revealed that mZV1 particles have approximately a 10-30 times lower corrosion rate than nZVI particles. A good correlation was found between surface area normalized corrosion rate (R-SA) and reaction rate constants (K-SA) of PCE, TCE, cDCE and 1,1,1-TCA. Generally, particles with higher degradation rates also have faster corrosion rates, but exceptions do exists. In a second phase, the hydrogen evolution was also monitored during batch tests in the presence of aquifer material and real groundwater. A 4-9 times higher corrosion rate of mZV1 particles was observed under the natural environment in comparison with the aquifer free artificial condition, which can be attributed to the low pH of the aquifer and its buffer capacity. A corrosion model was calibrated on the batch experiments to take into account the inhibitory effects of the corrosion products (dissolved iron, hydrogen and OH-) on the iron corrosion rate. (C) 2014 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000335109200003 Publication Date 2014-02-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3894 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:117179 Serial 7738
Permanent link to this record
 

 
Author Decostere, B.; Coppens, J.; Vervaeren, H.; Vlaeminck, S.E.; De Gelder, L.; Boon, N.; Nopens, I.; Van Hulle, S.W.H.
Title Kinetic exploration of intracellular nitrate storage in marine microalgae Type A1 Journal article
Year 2017 Publication Journal of environmental science and health : part A: toxic/hazardous substances and environmental engineering Abbreviated Journal
Volume 52 Issue 14 Pages 1303-1311
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this study, a recently developed model accounting for intracellular nitrate storage kinetics was thoroughly studied to understand and compare the storage capacity of Phaeodactylum tricornutum and Amphora coffeaeformis. In the first stage the identifiability of the biokinetic parameters was examined. Next, the kinetic model was calibrated for both microalgal species based on experimental observations during batch growth experiments. Two kinetic parameters were calibrated, namely the maximum specific growth rate (mu(max)) and the nitrate storage rate (k(sto)). A significant difference was observed for the nitrate storage rate between both species. For P. tricornutum, the nitrate storage rate was much higher (k(sto) = 0.036m(3) g(-1) DW d(-1)) compared to A. coffeaeformis (k(sto) = 0.0004m(3) g(-1) DW d(-1)). This suggests that P. tricornutum has a more efficient nitrate uptake ability and intracellular nitrate storage capacity and also indicates the need for determination of k(sto) in order to quantify nitrate storage.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000415634300004 Publication Date 2017-09-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1093-4529; 1532-4117 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:147467 Serial 8137
Permanent link to this record
 

 
Author Carniato, L.; Schoups, G.; Seuntjens, P.; Van Nooten, T.; Simons, Q.; Bastiaens, L.
Title Predicting longevity of iron permeable reactive barriers using multiple iron deactivation models Type A1 Journal article
Year 2012 Publication Journal of contaminant hydrology Abbreviated Journal
Volume 142 Issue Pages 93-108
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this study we investigate the model uncertainties involved in predicting long-term permeable reactive barrier (PRB) remediation efficiency based on a lab-scale column experiment under accelerated flow conditions. A PRB consisting of 20% iron and 80% sand was simulated in a laboratory-scale column and contaminated groundwater was pumped into the column for approximately 1 year at an average groundwater velocity of 3.7E – 1 m d(-1). Dissolved contaminants (PCE. TCE, cis-DCE, trans-DCE and VC) and inorganic (Ca2+, Fe2+, TIC and pH) concentrations were measured in groundwater sampled at different times and at eight different distances along the column. These measurements were used to calibrate a multi-component reactive transport model, which subsequently provided predictions of long-term PRB efficiency under reduced flow conditions (i.e., groundwater velocity of 1.4E -3 m d(-1)), representative of a field site of interest in this study. Iron reactive surface reduction due to mineral precipitation and iron dissolution was simulated using four different models. All models were able to reasonably well reproduce the column experiment measurements, whereas the extrapolated long-term efficiency under different flow rates was significantly different between the different models. These results highlight significant model uncertainties associated with extrapolating long-term PRB performance based on lab-scale column experiments. These uncertainties should be accounted for at the PRB design phase, and may be reduced by independent experiments and field observations aimed at a better understanding of reactive surface deactivation mechanisms in iron PRBs. (C) 2012 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000312753000009 Publication Date 2012-09-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-7722 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:106010 Serial 8402
Permanent link to this record
 

 
Author Carniato, L.; Schoups, G.; van de Giesen, N.; Seuntjens, P.; Bastiaens, L.; Sapion, H.
Title Highly parameterized inversion of groundwater reactive transport for a complex field site Type A1 Journal article
Year 2015 Publication Journal of contaminant hydrology Abbreviated Journal
Volume 173 Issue Pages 38-58
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this study a numerical groundwater reactive transport model of a shallow groundwater aquifer contaminated with volatile organic compounds is developed. In addition to advective-dispersive transport, the model includes contaminant release from source areas, natural attenuation, abiotic degradation by a permeable reactive barrier at the site, and dilution by infiltrating rain. Aquifer heterogeneity is parameterized using pilot points for hydraulic conductivity, specific yield and groundwater recharge. A methodology is developed and applied to estimate the large number of parameters from the limited data at the field site (groundwater levels, groundwater concentrations of multiple chemical species, point-scale measurements of soil hydraulic conductivity, and lab-scale derived information on chemical and biochemical reactions). The proposed methodology relies on pilot point parameterization of hydraulic parameters and groundwater recharge, a regularization procedure to reconcile the large number of spatially distributed model parameters with the limited field data, a step-wise approach for integrating the different data sets into the model, and high performance computing. The methodology was proven to be effective in reproducing multiple contaminant plumes and in reducing the prior parameter uncertainty of hydraulic conductivity and groundwater recharge. Our results further indicate that contaminant transport predictions are strongly affected by the choice of the groundwater recharge model and flow parameters should be identified using both head and concentration measurements. (C) 2014 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000348878900004 Publication Date 2014-12-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-7722 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:125290 Serial 8041
Permanent link to this record
 

 
Author Düking, R.; Gielis, J.; Liese, W.
Title Carbon flux and carbon stock in a bamboo stand and their relevance for mitigating climate change Type A3 Journal article
Year 2011 Publication Bamboo Science & Culture Abbreviated Journal
Volume 24 Issue 1 Pages 1-6
Keywords A3 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this report we describe the basics of biological carbon fixation in bamboo forests. Confusing carbon stock with carbon flux has led to false expectations on the significance of bamboo forests as carbon sinks. Furthermore, misunderstandings about the growth of bamboo culms can lead to highly exaggerated expectations on the productivity of bamboo.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1535-7635 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:91091 Serial 7578
Permanent link to this record
 

 
Author Meulebroeck, W.; Baert, K.; Wouters, H.; Cosyns, P.; Ceglia, A.; Cagno, S.; Janssens, K.; Nys, K.; Terryn, H.; Thienpont, H.
Title The identification of chromophores in ancient glass by the use of UV-VIS-NIR spectroscopy Type A1 Journal article
Year 2010 Publication Proceedings of the Society of Photo-optical Instrumentation Engineers Abbreviated Journal
Volume 7726 Issue Pages 77260d-12
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (down) In this publication optical spectroscopy is considered to be a supplementary technique to study ancient colored glass. It results from a systematic study of the UV-VIS-NIR transmission spectra of intentionally colored glass fragments from various archaeological and historical sites and dated from the Roman period to the 21th century AD. The main goal consists of defining optical sensing parameters for this type of material. The considered colorants are iron, cobalt, manganese, copper and chromium. It is proved that many cases exist where optical spectroscopy can be seen as a straightforward, non-destructive, low-cost and in-situ applicable technique in identifying authentic material or to obtain information about the origin of the material. Possible sensing parameters are defined as the absence/presence of absorption bands characteristic for a specific coloring metal oxide and the spectral position of these bands. These parameters could reveal information about the applied furnace conditions and/or to the composition of the glass matrix. It is shown that the cobalt absorption band situated around 535 nm for soda rich glasses (Roman and industrial times) is shifted towards 526 nm for potash rich glasses (medieval and post-medieval times).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000285287900011 Publication Date 2010-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0277-786x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 10 Open Access
Notes ; ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:111316 Serial 5650
Permanent link to this record
 

 
Author Vermeulen, M.; Sanyova, J.; Janssens, K.
Title Identification of artificial orpiment in the interior decorations of the Japanese tower in Laeken, Brussels, Belgium Type A1 Journal article
Year 2015 Publication Heritage science Abbreviated Journal
Volume 3 Issue Pages Unsp 9
Keywords A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (down) In this paper, we used a multi-technique approach in order to identify the arsenic sulfide pigment used in the decorative panels of the Japanese tower in Laeken, Belgium. Our attention was drawn to this particular pigment because of its relatively good conservation state, despite its known tendency to fade over time when exposed to light. The pigment was used with different painting techniques, bound with oil and urushi in the lacquers and with an aqueous binder in the mat relief panels. In the latter case it is always applied as an underlayer mixed with ultramarine blue. This quite unusual pigment mixture also shows a good state of preservation. In this study, the orpiment used for the Japanese tower has been identified as an amorphous arsenic sulfide glass (AsxSx) with the aid of light microscopy, PLM, SEM-EDX and Raman microscopy. The pigment features different degrees of As4S4 monomer units in its structure, also known as realgar-like nano-phases. This most likely indicates different synthesis processes as the formation of these As4S4 monomers is dependent of the quenching temperature (Tq) to which the artificial pigment is exposed during the preparation phase.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000356920400001 Publication Date 2015-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-7445 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 17 Open Access
Notes ; We cordially thank Gunter Grundmann for his precious advice regarding PLM and arsenic sulfide glass. This research is made possible with the support of the Belgian Science Policy Office (BELSPO) through the research program Science for a Sustainable Development – SDD, “Long-term role and fate of metal-sulfides in painted works of art – S2ART” (SD/RI/04A). ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:124904 Serial 5649
Permanent link to this record
 

 
Author Gielis, J.; Tavkhelidze, I.; Ricci, P.E.
Title About “bulky” links generated by generalized Möbius-Listing bodies GML2n Type A2 Journal article
Year 2013 Publication Journal of mathematical sciences Abbreviated Journal
Volume 193 Issue 3 Pages 449-460
Keywords A2 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this paper, we consider the bulky knots and bulky links, which appear after cutting of a Generalized MöbiusListing GMLn2 body (with the radial cross section a convex plane 2-symmetric figure with two vertices) along a different Generalized MöbiusListing surfaces GMLn2 situated in it. The aim of this report is to investigate the number and geometric structure of the independent objects that appear after such a cutting process of GMLn2 bodies. In most cases we are able to count the indices of the resulting mathematical objects according to the known classification for the standard knots and links.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2013-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1072-3374; 1573-8795 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:110953 Serial 7404
Permanent link to this record
 

 
Author Bafekry, A.; Stampfl, C.; Ghergherehchi, M.
Title Strain, electric-field and functionalization induced widely tunable electronic properties in MoS2/BC3, /C3N and / C3N4 van der Waals heterostructures Type A1 Journal article
Year 2020 Publication Nanotechnology (Bristol. Print) Abbreviated Journal
Volume Issue Pages 295202 pp
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (down) In this paper, the effect of BC3, C3N and C3N4BC(3) and MoS2/C(3)N4 heterostructures are direct semiconductors with band gaps of 0.4 and 1.74 eV, respectively, while MoS2/C3N is a metal. Furthermore, the influence of strain and electric field on the electronic structure of these van der Waals heterostructures is investigated. The MoS2/BC3 heterostructure, for strains larger than -4%, transforms it into a metal where the metallic character is maintained for strains larger than -6%. The band gap decreases with increasing strain to 0.35 eV (at +2%), while for strain (>+6%) a direct-indirect band gap transition is predicted to occur. For the MoS2/C3N heterostructure, the metallic character persists for all strains considered. On applying an electric field, the electronic properties of MoS2/C3N4 are modified and its band gap decreases as the electric field increases. Interestingly, the band gap reaches 30 meV at +0.8 V/angstrom, and with increase above +0.8 V/angstrom, a semiconductor-to-metal transition occurs. Furthermore, we investigated effects of semi- and full-hydrogenation of MoS2/C3N and we found that it leads to a metallic and semiconducting character, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000532366000001 Publication Date 2020-04-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 0957-4484 Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 19 Open Access
Notes ; This work has supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT)(NRF-2017R1A2B2011989). ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:169523 Serial 6444
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Author Huyskens, C.; Brauns, E.; van Hoof, E.; de Wever, H.
Title A new method for the evaluation of the reversible and irreversible fouling propensity of MBR mixed liquor Type A1 Journal article
Year 2008 Publication Journal of membrane science Abbreviated Journal
Volume 323 Issue 1 Pages 185-192
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this paper, a new fouling measurement method is presented as a pragmatic approach to determine a mixed liquor's fouling propensity. The MBR-VFM (VITO Fouling Measurement) uses a specific measurement protocol consisting of alternating filtration and physical cleaning steps, which enables the calculation of both the reversible and the irreversible fouling resistances. The MBR-VFM principle, set-up and measurement protocol are described as well as the evaluation of the fouling measurement method. Finally, the MBR-VFM was validated by comparing the fouling propensity measured on-line by the MBR-VFM in a lab-scale MBR with the fouling of the MBR membranes themselves. Our experiments indicated that the MBR-VFM can accurately measure fouling and that it can even be detected earlier than can be seen from the on-line filtration data of the lab-scale system itself. Furthermore, the differences measured in reversible and irreversible fouling seemed to be related to the observed impact of physical and chemical cleaning respectively. Therefore, the application of the MBR-VFM as an on-line sensor in an advanced control system, enabling the deployment of the measured fouling data for the control of membrane cleaning, seems feasible and will be tested in the near future.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000258904600023 Publication Date 2008-06-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0376-7388 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:88401 Serial 8303
Permanent link to this record
 

 
Author De Meyer, S.; Vanmeert, F.; Janssens, K.; Storme, P.
Title A mobile scanner for xrpd-imaging of paintings in transmission and reflection geometry Type P1 Proceeding
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
Volume Issue Pages 29-38
Keywords P1 Proceeding; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
Abstract (down) 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000430517600002 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-80-87108-75-8 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:189869 Serial 7392
Permanent link to this record
 

 
Author Pourtois, G.; Dabral, A.; Sankaran, K.; Magnus, W.; Yu, H.; de de Meux, A.J.; Lu, A.K.A.; Clima, S.; Stokbro, K.; Schaekers, M.; Houssa, M.; Collaert, N.; Horiguchi, N.
Title Probing the intrinsic limitations of the contact resistance of metal/semiconductor interfaces through atomistic simulations Type P1 Proceeding
Year 2017 Publication Semiconductors, Dielectrics, And Metals For Nanoelectronics 15: In Memory Of Samares Kar Abbreviated Journal
Volume Issue Pages 303-311
Keywords P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (down) In this contribution, we report a fundamental study of the factors that set the contact resistivity between metals and highly doped semiconductors. We investigate the case of n-type doped Si contacted with amorphous TiSi combining first-principles calculations with Non-Equilibrium Green functions transport simulations. The intrinsic contact resistivity is found to saturate at similar to 2x10(-10) Omega.cm(2) with the doping concentration and sets an intrinsic limit to the ultimate contact resistance achievable for n-doped Si vertical bar amorphous-TiSi. This limit arises from the intrinsic properties of the semiconductor and of the metal such as their electron effective masses and Fermi energies. We illustrate that, in this regime, contacting metals with a heavy electron effective mass helps reducing the interface intrinsic contact resistivity.
Address
Corporate Author Thesis
Publisher Electrochemical soc inc Place of Publication Pennington Editor
Language Wos 000426271800028 Publication Date 2017-10-17
Series Editor Series Title Abbreviated Series Title
Series Volume 80 Series Issue 1 Edition
ISSN 978-1-62332-470-4; 978-1-60768-818-1 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 1 Open Access Not_Open_Access
Notes ; ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:149966 Serial 4976
Permanent link to this record
 

 
Author de Jong van Coevorden, C.M.; Gielis, J.; Caratelli, D.
Title Application of Gielis transformation to the design of metamaterial structures Type A1 Journal article
Year 2018 Publication Journal of physics : conference series Abbreviated Journal
Volume 963 Issue Pages Unsp 012008
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In this communication, the use of Gielis transformation to design more compact metamaterial unit cells is explored. For this purpose, transformed complementary split ring resonators and spiral resonators are coupled to micro-strip lines and theirbehaviour is investigated. The obtained results confirm that the useof the considered class of supershaped geometries enables the synthesis of very compact scalable microwave components.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000435022800008 Publication Date 2018-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6588; 1742-6596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:150947 Serial 7475
Permanent link to this record
 

 
Author Hamidi-Asl, E.; Dardenne, F.; Pilehvar, S.; Blust, R.; De Wael, K.
Title Unique properties of core shell Ag@Au nanoparticles for the aptasensing of bacterial cells Type A1 Journal article
Year 2016 Publication Chemosensors Abbreviated Journal
Volume 4 Issue 3 Pages 16
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (down) In this article, it is shown that the efficiency of an electrochemical aptasensing device is influenced by the use of different nanoparticles (NPs) such as gold nanoparticles (Au), silver nanoparticles (Ag), hollow gold nanospheres (HGN), hollow silver nanospheres (HSN), silvergold core shell (Ag@Au), goldsilver core shell (Au@Ag), and silvergold alloy nanoparticles (Ag/Au). Among these nanomaterials, Ag@Au core shell NPs are advantageous for aptasensing applications because the core improves the physical properties and the shell provides chemical stability and biocompatibility for the immobilization of aptamers. Self-assembly of the NPs on a cysteamine film at the surface of a carbon paste electrode is followed by the immobilization of thiolated aptamers at these nanoframes. The nanostructured (Ag@Au) aptadevice for Escherichia coli as a target shows four times better performance in comparison to the response obtained at an aptamer modified planar gold electrode. A comparison with other (core shell) NPs is performed by cyclic voltammetry and differential pulse voltammetry. Also, the selectivity of the aptasensor is investigated using other kinds of bacteria. The synthesized NPs and the morphology of the modified electrode are characterized by UV-Vis absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and electrochemical impedance spectroscopy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000382480000006 Publication Date 2016-08-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2227-9040 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 9 Open Access
Notes ; Ezat Hamidi-Asl was financially supported by Belspo (University of Antwerp). The authors are thankful to Femke De Croock for her technical support and to Stanislav Trashin for his worthwhile comments on the manuscript. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:135411 Serial 5886
Permanent link to this record
 

 
Author De Wael, K.; De Belder, S.; Pilehar, S.; Van Steenberge, G.; Herrebout, W.; Heering, H.A.
Title Enzyme-gelatin electrochemical biosensors : scaling down Type A1 Journal article
Year 2012 Publication Biosensors Abbreviated Journal
Volume 2 Issue Pages 101-113
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Molecular Spectroscopy (MolSpec)
Abstract (down) In this article we investigate the possibility of scaling down enzyme-gelatin modified electrodes by spin coating the enzyme-gelatin layer. Special attention is given to the electrochemical behavior of the selected enzymes inside the gelatin matrix. A glassy carbon electrode was used as a substrate to immobilize, in the first instance, horse heart cytochrome c (HHC) in a gelatin matrix. Both a drop dried and a spin coated layer was prepared. On scaling down, a transition from diffusion controlled reactions towards adsorption controlled reactions is observed. Compared to a drop dried electrode, a spin coated electrode showed a more stable electrochemical behavior. Next to HHC, we also incorporated catalase in a spin coated gelatin matrix immobilized on a glassy carbon electrode. By spincoating, highly uniform sub micrometer layers of biocompatible matrices can be constructed. A full electrochemical study and characterization of the modified surfaces has been carried out. It was clear that in the case of catalase, gluteraldehyde addition was needed to prevent leaking of the catalase from the gelatin matrix.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2012-03-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-6374 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:96507 Serial 5606
Permanent link to this record
 

 
Author Ortiz-Aguayo, D.; Ceto, X.; De Wael, K.; del Valle, M.
Title Resolution of opiate illicit drugs signals in the presence of some cutting agents with use of a voltammetric sensor array and machine learning strategies Type A1 Journal article
Year 2022 Publication Sensors and actuators : B : chemical Abbreviated Journal
Volume 357 Issue Pages 131345
Keywords A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract (down) In the present work, the resolution and quantification of mixtures of different opiate compounds in the presence of common cutting agents using an electronic tongue (ET) is evaluated. More specifically, ternary mixtures of heroin, morphine and codeine were resolved in the presence of caffeine and paracetamol. To this aim, an array of three carbon screen-printed electrodes were modified with different ink-like solutions of graphite, cobalt (II) phthalocyanine and palladium, and their responses towards the different drugs were characterized by means of square wave voltammetry (SWV). Developed sensors showed a good performance with good linearity at the mu M level, LODs between 1.8 and 5.3 mu M for the 3 actual drugs, and relative standard deviation (RSD) ca. 2% for over 50 consecutive measurements. Next, a quantitative model that allowed the identification and quantification of the individual substances from the overlapped voltammograms was built using partial least squares regression (PLS) as the modeling tool. With this approach, quantification of the different drugs was achieved at the mu M level, with a total normalized root mean square error (NRMSE) of 0.084 for the test subset.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000745113900003 Publication Date 2021-12-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-4005 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved no
Call Number UA @ admin @ c:irua:185446 Serial 8922
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Author Celik, N.; Čevik, U.; Celik, A.; Koz, B.
Title Natural and artificial radioactivity measurements in Eastern Black Sea region of Turkey Type A1 Journal article
Year 2009 Publication Journal of hazardous materials Abbreviated Journal
Volume 162 Issue 1 Pages 146-153
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (down) In the present work, naturally occurring radionuclides of (226)Ra, (232)Th and (40)K were measured in soil samples collected from the Eastern Black Sea region of Turkey. It was found that the activity concentrations ranged from 12 to 120 Bq kg(-1) for (226)Ra, from 13 to 121 Bq kg(-1) for (232)Th and from 204 to 1295 Bq kg(-1) for (40)K. Besides naturally occurring radionuclides, (137)Cs activity concentration was measured in soil, lichen and moss samples and it was found that (137)Cs activity concentration ranged from 27 to 775 Bq kg(-1) with for soil, from 29 to 879 Bq kg(-1) for lichen and from 67 to 1396 Bq kg(-1) for moss samples. Annual effective doses due to the naturally occurring radionuclides and (137)CS were estimated. Ecological half-lives of (137)CS in lichen and moss species were estimated. The decrease of the activity concentrations in the present measurements (2007) relative to those in 1993 indicated ecological half-lives between 1.36 and 2.96 years for lichen and between 1.35 and 2.85 years for moss species. (C) 2008 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000263149400019 Publication Date 2008-05-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3894 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:94562 Serial 8296
Permanent link to this record
 

 
Author Boumahdi, M.; El Amrani, C.; Denys, S.
Title An innovative air purification method and neural network algorithm applied to urban streets Type A1 Journal article
Year 2019 Publication International journal of embedded and real-time communication systems Abbreviated Journal
Volume 10 Issue 4 Pages 1-19
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In the present work, multiphysics modeling was used to investigate the feasibility of a photocatalysis-based outdoor air purifying solution that could be used in high polluted streets, especially street canyons. The article focuses on the use of a semi-active photocatalysis in the surfaces of the street as a solution to remove anthropogenic pollutants from the air. The solution is based on lamellae arranged horizontally on the wall of the street, coated with a photocatalyst (TiO2), lightened with UV light, with a dimension of 8 cm × 48 cm × 1 m. Fans were used in the system to create airflow. A high purification percentage was obtained. An artificial neural network (ANN) was used to predict the optimal purification method based on previous simulations, to design purification strategies considering the energy cost. The ANN was used to forecast the amount of purified with a feed-forward neural network and a backpropagation algorithm to train the model.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2019-09-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-5225-7199-5 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:162595 Serial 8103
Permanent link to this record
 

 
Author Vishwakarma, M.; Varandani, D.; Hendrickx, M.; Hadermann, J.; Mehta, B.R.
Title Nanoscale photovoltage mapping in CZTSe/CuxSe heterostructure by using kelvin probe force microscopy Type A1 Journal article
Year 2020 Publication Materials Research Express Abbreviated Journal
Volume 7 Issue 1 Pages 016418
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (down) In the present work, kelvin probe force microscopy (KPFM) technique has been used to study the CZTSe/CuxSe bilayer interface prepared by multi-step deposition and selenization process of metal precursors. Transmission electron microscopy (TEM) confirmed the bilayer configuration of the CZTSe/CuxSe sample. Two configuration modes (surface mode and junction mode) in KPFM have been employed in order to measure the junction voltage under illumination conditions. The results show that CZTSe/CuxSe has small junction voltage of similar to 21 mV and the presence of CuxSe secondary phase in the CZTSe grain boundaries changes the workfunction of the local grain boundaries region. The negligible photovoltage difference between grain and grain boundaries in photovoltage image indicates that CuxSe phase deteriorates the higher photovoltage at grain boundaries normally observed in CZTSe based device. These results can be important for understanding the role of secondary phases in CZTSe based junction devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000520120900001 Publication Date 2019-12-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes ; Authors acknowledges support provided DST in the forms of InSOL and Indo-Swiss projects. We also acknowledge Joke Hadermann EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Belgium for helping in TEM measurements. M V Manoj Vishwakarma acknowledges IIT Delhi for MHRD fellowship. Prof B R Mehta acknowledges the support of the Schlumberger chair professorship. M V also acknowledges the support of DST-FIST Raman facility. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:167843 Serial 6567
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Author Jochems, P.; Mueller, T.; Satyawali, Y.; Diels, L.; Dejonghe, W.; Hanefeld, U.
Title Active site titration of immobilized beta-galactosidase for the determination of active enzymes Type A1 Journal article
Year 2015 Publication Biochemical engineering journal Abbreviated Journal
Volume 93 Issue Pages 137-141
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In the present study, an active site titration method is demonstrated, to determine the amount of active enzyme (beta-galactosidase), immobilized on a support. Two types of supports were investigated, viz, amino acrylic resin and a mixed matrix membrane. Furthermore, 2',4'-dinitrophenyl 2-deoxy-2-fluoro-beta-D-galactopyranoside was used as an inhibitor for the active site titration of immobilized beta-galactosidase obtained from Kluyveromyces lactis. Using the active site titration, approximately 8.3 mg of active enzyme was found on 1 g of dried commercially available SPRIN imibond, which is an amino acrylic resin with covalently bound beta-galactosidase obtained from K. lactis. However, this method, in its present form, was not effective on the mixed matrix membranes due to the irreversible partial adsorption of the leaving group (2',4'-dinitrophenolate) by the membrane. This observation implied that it is important to investigate interactions between the support and the used inhibitor and leaving group. (C) 2014 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000347362100018 Publication Date 2014-10-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1369-703x; 1873-295x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:123763 Serial 7417
Permanent link to this record
 

 
Author Li, T.; Piltz, B.; Podola, B.; Dron, A.; de Beer, D.; Melkonian, M.
Title Microscale profiling of photosynthesis-related variables in a highly productive biofilm photobioreactor Type A1 Journal article
Year 2016 Publication Biotechnology and bioengineering Abbreviated Journal
Volume 113 Issue 5 Pages 1046-1055
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In the present study depth profiles of light, oxygen, pH and photosynthetic performance in an artificial biofilm of the green alga Halochlorella rubescens in a porous substrate photobioreactor (PSBR) were recorded with microsensors. Biofilms were exposed to different light intensities (50-1,000mol photons m(-2) s(-1)) and CO2 levels (0.04-5% v/v in air). The distribution of photosynthetically active radiation showed almost identical trends for different surface irradiances, namely: a relatively fast drop to a depth of about 250 mu m, (to 5% of the incident), followed by a slower decrease. Light penetrated into the biofilm deeper than the Lambert-Beer Law predicted, which may be attributed to forward scattering of light, thus improving the overall light availability. Oxygen concentration profiles showed maxima at a depth between 50 and 150m, depending on the incident light intensity. A very fast gas exchange was observed at the biofilm surface. The highest oxygen concentration of 3.2mM was measured with 1,000mol photons m(-2) s(-1) and 5% supplementary CO2. Photosynthetic productivity increased with light intensity and/or CO2 concentration and was always highest at the biofilm surface; the stimulating effect of elevated CO2 concentration in the gas phase on photosynthesis was enhanced by higher light intensities. The dissolved inorganic carbon concentration profiles suggest that the availability of the dissolved free CO2 has the strongest impact on photosynthetic productivity. The results suggest that dark respiration could explain previously observed decrease in growth rate over cultivation time in this type of PSBR. Our results represent a basis for understanding the complex dynamics of environmental variables and metabolic processes in artificial phototrophic biofilms exposed to a gas phase and can be used to improve the design and operational parameters of PSBRs. Biotechnol. Bioeng. 2016;113: 1046-1055. (c) 2015 Wiley Periodicals, Inc.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000373476700013 Publication Date 2015-10-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-3592 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:133255 Serial 8248
Permanent link to this record
 

 
Author Caratelli, D.; Gielis, J.; Ricci, P.E.; Tavkhelidze, I.
Title Some properties of “bulky” links, generated by Generalized Möbius Listing's bodies GML4n Type A2 Journal article
Year 2016 Publication Journal of mathematical sciences Abbreviated Journal
Volume 216 Issue 4 Pages 509-518
Keywords A2 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In the present paper, we consider the bulky knots and bulky links that appear after cutting of generalized MöbiusListing GML 4 n bodies (with corresponding radial cross sections square) along different generalized MöbiusListing surfaces GML 2 n situated in it. The aim of this article is to examine the number and geometric structure of independent objects that appear after such a cutting process of GML 4 n bodies. In most cases, we are able to count the indices of the resulting mathematical objects according to the known tabulation for knots and links of small complexity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2016-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1072-3374; 1573-8795 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:133948 Serial 8554
Permanent link to this record
 

 
Author Tavkhelidze, I.; Cassisa, C.; Gielis, J.; Ricci, P.E.
Title About “bulky” links, generated by generalized Möbius Listing's bodies GML3n Type A1 Journal article
Year 2013 Publication Matematica e applicazioni : atti della Accademia nazionale dei Lincei Abbreviated Journal
Volume 24 Issue 1 Pages 11-38
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract (down) In the present paper we consider the “bulky knots'' and ”bulky links'', which appear after cutting a Generalized Möbius Listing's GMLn3 body (whose radial cross section is a plane 3-symmetric figure with three vertices) along different Generalized Möbius Listing's surfaces GMLn2 situated in it. This article is aimed to investigate the number and geometric structure of the independent objects appearing after such a cutting process of GMLn3 bodies. In most cases we are able to count the indices of the resulting mathematical objects according to the known tabulation for Knots and Links of small complexity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000316567700002 Publication Date 2013-03-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1120-6357 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:107174 Serial 7405
Permanent link to this record
 

 
Author Van Grieken, R.; Darchuk, L.; Kontozova, V.; Potgieter-Vermaak, S.; van Meel, K.; Stefaniak, E.; Worobiec, A.
Title Integration of analysis techniques of different scales using X ray induced and electron induced X ray spectrometry for applications in preventive conservation and environmental monitoring Type H2 Book chapter
Year 2011 Publication Abbreviated Journal
Volume Issue Pages 53-56 T2 - Integration of nuclear spectrometry met
Keywords H2 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract (down) In the past years, and also within the framework of this CRP, we have used a combination of several nuclear and non-nuclear techniques in fundamental research and especially in various applications. Most work has been done with energy-dispersive X ray fluorescence in combination with electron probe X ray microanalysis, but several other more common analysis techniques have been used as well. The applications have included mostly preventive conservation (e.g. characterisation of damaging atmospheric particles in many museums) and environmental monitoring (e.g. for atmospheric particles in relation to their health effects in outdoor and especially indoor environments). Fundamental aspects have been in the optimising of interfaced electron microprobe and Raman microprobe analysis and the evaluation of the potential of such an instrument for atmospheric aerosols; quite a few unexpected and unpredicted problems have appeared in the latter study.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-92-0-121310-5 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:97169 Serial 8110
Permanent link to this record
 

 
Author Chekol Zewdie, M.; Moretti, M.; Tenessa, D.B.; Ayele, Z.A.; Nyssen, J.; Tsegaye, E.A.; Minale, A.S.; Van Passel, S.
Title Agricultural technical efficiency of smallholder farmers in Ethiopia : a stochastic frontier approach Type A1 Journal article
Year 2021 Publication Land Abbreviated Journal
Volume 10 Issue 3 Pages 246
Keywords A1 Journal article; Engineering Management (ENM)
Abstract (down) In the past decade, to improve crop production and productivity, Ethiopia has embarked on an ambitious irrigation farming expansion program and has introduced new large- and small-scale irrigation initiatives. However, in Ethiopia, poverty remains a challenge, and crop productivity per unit area of land is very low. Literature on the technical efficiency (TE) of large-scale and small-scale irrigation user farmers as compared to the non-user farmers in Ethiopia is also limited. Investigating smallholder farmers' TE level and its principal determinants is very important to increase crop production and productivity and to improve smallholder farmers' livelihood and food security. Using 1026 household-level cross-section data, this study adopts a technology flexible stochastic frontier approach to examine agricultural TE of large-scale irrigation users, small-scale irrigation users and non-user farmers in Ethiopia. The results indicate that, due to poor extension services and old-style agronomic practices, the mean TE of farmers is very low (44.33%), implying that there is a wider room for increasing crop production in the study areas through increasing the TE of smallholder farmers without additional investment in novel agricultural technologies. Results also show that large-scale irrigation user farmers (21.05%) are less technically efficient than small-scale irrigation user farmers (60.29%). However, improving irrigation infrastructure shifts the frontier up and has a positive impact on smallholder farmers' output.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000633846200001 Publication Date 2021-03-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-445x ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:177647 Serial 6913
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Author Vereecke, G.; De Coster, H.; Van Alphen, S.; Carolan, P.; Bender, H.; Willems, K.; Ragnarsson, L.-A.; Van Dorpe, P.; Horiguchi, N.; Holsteyns, F.
Title Wet etching of TiN in 1-D and 2-D confined nano-spaces of FinFET transistors Type A1 Journal article
Year 2018 Publication Microelectronic engineering Abbreviated Journal
Volume 200 Issue Pages 56-61
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (down) In the manufacturing of multi-Vt FinFET transistors, the gate material deposited in the nano-spaces left by the removed dummy gate must be etched back in mask-defined wafer areas. Etch conformality is a necessary condition for the control of under-etch at the boundary between areas defined by masking. We studied the feasibility of TiN etching by APM (ammonia peroxide mixture, also known as SC1) in nano-confined volumes representative of FinFET transistors of the 7 nm node and below, namely nanotrenches with 1-D confinement and nanoholes with 2-D confinement. TiN etching was characterized for rate and conformality using different electron microscopy techniques. Etching in closed nanotrenches was conformal, starting and progressing all along the 2-D seam, with a rate that was 38% higher compared to a planar film. Etching in closed nanoholes proved also to be conformal and faster than planar films, but with a delay to open the 1-D seam that seemed to depend strongly on small variations in the hole diameter. However, holes between the fins at the bottom of the removed dummy gate, are not circular and do present 2-D seams that should lend themselves for an easier start of conformal etching as compared to the circular nanoholes used in this study. Finally, to explain the higher etch rate observed in nano-confined features, concentrations of ions in nanoholes were calculated taking the overlap of electrostatic double layers (EDL) into account. With negatively charged TiN walls, as measured by streaming potential on planar films, ammonium was the dominant ion in nanoholes. As no chemical reaction proposed in the literature for TiN etching matched with this finding, we proposed that the formation of ammine complexes, dissolving the formed Ti oxide, was the rate-determining step.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000449134800010 Publication Date 2018-09-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-9317 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:155414 Serial 8757
Permanent link to this record
 

 
Author Kashiwar, A.
Title TEM investigations of deformation mechanisms in nanocrystalline metals and multilayered composites Type Doctoral thesis
Year 2022 Publication Abbreviated Journal
Volume Issue Pages xvi, 129 p.
Keywords Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (down) In the last few decades, nanostructuring has driven significant attention towards the development of novel metallic materials with advanced mechanical properties. Nanocrystalline (nc) metals are a class of nanostructured materials with grain sizes smaller than about 100 nm. These exhibit outstanding mechanical strength and fatigue properties compared to their coarse-grained (cg) counterparts. These are promising candidates for application as structural or functional materials. Nc metals in the form of thin films are employed as hard coatings on bulk components, structural components, and conductive layers in various micro-/nanoscale devices. These structural components and devices are often subjected to cyclic stresses or fatigue loading. Under these cyclic stresses, nc metals tend to exhibit the Bauschinger effect (BE). The strength loss during the BE is of great importance concerning the strength-ductility trade-off in nc metals. Furthermore, contact surfaces of the engineering components in service often undergo relative motion and are subject to both friction and wear. These extreme loading conditions demand nc metals with tailored interfacial characteristics for improved tribological performance. Aiming at ensuring high reliability and mechanical robustness for optimum performance of these components, there has been a strong motivation for understanding the mechanical properties and governing deformation mechanisms in nc metallic materials. This thesis aimed at in-depth investigation of microstructures at micro-/nanoscales using state-of-the-art in situ and ex situ transmission electron microscopy (TEM) to develop a closer link between the deformation structure and underlying deformation mechanisms in some nc metallic materials. The thesis has primarily focused on the in situ TEM nanomechanics of the BE and rotational deformation of grains in nc palladium thin films. A sputtered thin film of nc Pd was deformed inside TEM by cyclic loading-unloading experiments and the evolving microstructure was studied in real-time under different TEM imaging modes. The stress-strain response of the film exhibited a characteristic non-linear unloading behavior confirming the BE in the film. The corresponding bright-field TEM imaging revealed evidence of partially reversible dislocation activity. Towards a quantitative understanding of the deformation structure in real-time, in situ nanomechanical testing was coupled with precession-assisted automated crystal orientation mapping in scanning TEM (ACOM-STEM). Global ACOM-STEM analysis offered crystal orientation of a large number of grains at different states of deformation and confirmed partially reversible rotations of nanosized grains fitting to the observed BE during loading and unloading. Analysis of intragranular rotations showed substantial changes in the sub-structure within most of these grains indicating a dominant role of dislocation-based processes in driving these rotations. Globally, an unusually random evolution of texture was seen that demonstrated the influence of deformation heterogeneity and grain interactions on the resulting texture characteristics in nc metals. In the quest of understanding the grain interactions, local investigations based on annular dark-field STEM imaging during loading-unloading showed reversible changes in the contrast of grains with sets of adjoining grains exhibiting a unique cooperative rotation. Local analysis of the density of geometrically necessary dislocations (GNDs) showed the formation of dislocation pile-up at grain boundaries due to the generation of back-stresses during unloading. Critical observations of the evolution of GND density offered greater insights into the mechanism of cooperative grain rotations and these rotations were related to grain structure and grain boundary characteristics. In addition to understanding the influence of grain structure and grain boundaries, the thesis has further investigated the role of heterointerfaces in sputtered Au-Cu and Cu-Cr nanocrystalline multilayered composites (NMCs) deformed under cyclic sliding contact. The microstructural evolution in the NMCs was investigated at different deformation states by classical TEM imaging, ACOM-STEM as well as energy-filtered TEM (EFTEM). Au-Cu NMC with an initial high density of twin boundaries deformed by stress-driven detwinning with a concurrent change in grain structure in both Au and Cu. The formation of a vortex structure was observed due to plastic flow instabilities at Au-Cu interfaces that led to codeformation and mechanical intermixing. Cu-Cr NMC showed a preferential grain growth in Cu layers whereas no noticeable change in the grain sizes was seen in Cr layers. The phase maps revealed sharp interfaces between Cu and Cr layers indicating no intermixing between the immiscible phases. EFTEM results exposed the cracking processes in Cr layers with a concurrent migration of Cu in the cracks. Overall, the thesis has attempted to analyze the competing deformation processes and relate these with the microstructural heterogeneity in terms of grain structure and GB and interfacial characteristics in nc metallic materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:189013 Serial 7343
Permanent link to this record