| |
Records |
Links |
|
Author |
Anaf, W.; Schalm, O. |
|
| |
Title |
Climatic quality evaluation by peak analysis and segregation of low-, mid-, and high-frequency fluctuations, applied on a historic chapel |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Building and environment |
Abbreviated Journal |
|
|
| |
Volume  |
148 |
Issue |
|
Pages |
286-293 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
|
| |
Abstract |
Heritage-related guidelines and standards recommend stable climatic conditions, since these contribute to the extension of heritage collections life. As a result, numerous museums and other heritage institutions implement (expensive) mitigation measures to achieve stable conditions. Nevertheless, temperature and relative humidity fluctuations are often still observed. This contribution demonstrates that the analysis of temperature and humidity peaks and drops helps to identify hazards which cause fluctuations in different frequency ranges. This hazard identification provides information on the type of mitigation actions that are required in the near future and in which order they need to be implemented. The approach is illustrated with a case study. A 22 month monitoring campaign was performed in a chapel in the center of Antwerp (Belgium) where the climatic conditions are controlled with a heating, ventilation and air conditioning (HVAC) system. Low-, mid- and high-frequency fluctuations were separated and discussed for their hazards. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000457116500024 |
Publication Date |
2018-11-15 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0360-1323 |
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:157569 |
Serial |
7672 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sfez, S.; De Meester, S.; Vlaeminck, S.E.; Dewulf, J. |
|
| |
Title |
Improving the resource footprint evaluation of products recovered from wastewater : a discussion on appropriate allocation in the context of circular economy |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Resources, conservation and recycling |
Abbreviated Journal |
|
|
| |
Volume |
148 |
Issue |
|
Pages |
132-144 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
Shifting from a linear to a circular economy has consequences on how the sustainability of products is assessed. This is the case for products recovered from resources such as sewage sludge. The “zero-burden” assumption is commonly used in Life Cycle Assessment and considers that waste streams are burden-free, which becomes debatable when comparing waste-based with virgin material-based products in the context of the growing circular economy. If waste streams are considered as resources rather than waste, upstream burdens should be partly allocated to all products to allow a fair comparison with their virgin material-based equivalents. In this paper, five allocation approaches are applied to allocate the resource use of upstream processes (consumer goods production) to products recovered from the processing of sewage sludge in the Netherlands, which produces biogas, (phosphorus-based) chemicals and building materials. Except for the approach which allocates 100% of the impact from resource recovery processes to the preceding consumer goods, the allocation approaches show a resource use 27 to 80% higher than with the “zero-burden” assumption. In this particular case, using these allocation approaches is likely to find little support from recyclers. The producers of household products, recyclers and policy makers should find a consensus to consider the shift from a linear to a circular economy in sustainability assessment studies while avoiding discouraging the implementation of recovery technologies. This paper suggests starting the discussion with the approach which allocates the impacts from upstream processes degressively to the downstream products as it best translates the industrial ecology principles. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000472242800012 |
Publication Date |
2019-05-28 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0921-3449 |
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:159887 |
Serial |
8072 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Alaerts, L.; Van Acker, K.; Rousseau, S.; De Jaeger, S.; Moraga, G.; Dewulf, J.; De Meester, S.; Van Passel, S.; Compernolle, T.; Bachus, K.; Vrancken, K.; Eyckmans, J. |
|
| |
Title |
Towards a more direct policy feedback in circular economy monitoring via a societal needs perspective |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Resources, conservation and recycling |
Abbreviated Journal |
Resour Conserv Recy |
|
| |
Volume |
149 |
Issue |
149 |
Pages |
363-371 |
|
| |
Keywords |
A1 Journal article; Economics; Engineering Management (ENM); Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
The increasing focus on circular economy at the level of governments and policy requires the development of appropriate indicators to effectively monitor the progress towards the circular economy. Currently two very different types of indicator areas are under development: (i) monitoring frameworks based on macro indicators that summarize the progress at (supra)national level, and (ii) micro indicators tailored towards assessing circularity at the level of products. It is not possible to obtain sufficiently direct feedback about the impact of policy interventions by either macro or micro indicators alone. In this paper, a conceptual approach is developed that aims to bridge the gap between the micro and macro level with meso level indicators, and thus ultimately deliver more direct feedback for policymakers, via the insertion of an extra level of meso indicators in between the macro and the micro level. These indicators have been extracted from a dedicated workshop that involved policy, sector and societal stakeholders. The aim of these indicators is to report on progress towards circular economy objectives based on the fulfillment of societal needs. In this way the consumption perspective is given a central position, and the role of circular business models is acknowledged. Following the development of the concept, the next steps towards tailored, flexible and agile monitoring frameworks for circular economy at (supra)national and regional level are outlined. The paper concludes with an illustrative example of the framework applied to the mobility system. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000483414300034 |
Publication Date |
2019-06-21 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0921-3449 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.313 |
Times cited |
1 |
Open Access |
|
|
| |
Notes |
; The authors are very grateful for financial support received from the Flemish administration via the Steunpunt Circulaire Economie (Policy Research Centre Circular Economy). This publication contains the opinions of the authors, not that of the Flemish administration. The Flemish administration will not carry any liability with respect to the use that can be made of the produced data or conclusions. The authors are also grateful to the numerous stakeholders for extended discussions and comments. ; |
Approved |
Most recent IF: 3.313 |
|
| |
Call Number |
UA @ admin @ c:irua:162774 |
Serial |
6271 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Alloul, A.; Wuyts, S.; Lebeer, S.; Vlaeminck, S.E. |
|
| |
Title |
Volatile fatty acids impacting phototrophic growth kinetics of purple bacteria : paving the way for protein production on fermented wastewater |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Water research |
Abbreviated Journal |
|
|
| |
Volume |
152 |
Issue |
|
Pages |
138-147 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
Nutrient losses in our food chain severely surpass our planetary boundaries. Resource recovery can contribute to mitigation, for instance through converting wastewater resources to microbial protein for animal feed. Wastewater typically holds a complex mixture of organics, posing a challenge to selectively produce heterotrophic biomass. Ensuring the product's quality could be achieved by anaerobic generation of volatile fatty acids (VFAs) followed by photoheterotrophic production of purple non-sulfur bacteria (PNSB) with infrared light. This study aimed to determine the most suitable PNSB culture for VFA conversion and map the effect of acetate, propionate, butyrate and a VFA mixture on growth and biomass yield. Six cultures were screened in batch: (i) Rhodopseudomonas palustris, (ii) Rhodobacter sphaeroides, (iii) Rhodospirillum rubrum, (iv) a 3-species synthetic community (i+ii+iii), (v) a community enriched on VFA holding Rb. capsulatus, and (vi) Rb. capsulatus (isolate v). The VFA mixture elevated growth rates with a factor 1.32.5 compared to individual VFA. Rb. capsulatus showed the highest growth rates: 1.82.2 d−1 (enriched) and 2.33.8 d−1 (isolated). In a photobioreactor (PBR) inoculated with the Rb. capsulatus enrichment, decreasing sludge retention time (SRT) yielded lower biomass concentrations, yet increased productivities, reaching 1.7 g dry weight (DW) L−1 d−1, the highest phototrophic rate reported thus far, and a growth rate of up to 5 d−1. PNSB represented 2657% of the community and the diversity index was low (37), with a dominance of Rhodopseudomonas at long SRT and Rhodobacter at short SRT. The biomass yield for all cultures, in batch and reactor cultivation, approached 1 g CODBiomass g−1 CODRemoved. An economic estimation for a two-stage approach on brewery wastewater (load 2427 kg COD d−1) showed that 0.5 d SRT allowed for the lowest production cost ( 10 kg−1 DW; equal shares for capex and opex). The findings strengthen the potential for a novel two-stage approach for resource recovery from industrial wastewater, enabling high-rate PNSB production. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000458223900013 |
Publication Date |
2018-12-27 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0043-1354; 1879-2448 |
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:156462 |
Serial |
8739 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Pourbabak, S.; Montero-Sistiaga, M.L.; Schryvers, D.; Van Humbeeck, J.; Vanmeensel, K. |
|
| |
Title |
Microscopic investigation of as built and hot isostatic pressed Hastelloy X processed by Selective Laser Melting |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Materials characterization |
Abbreviated Journal |
Mater Charact |
|
| |
Volume |
153 |
Issue |
|
Pages |
366-371 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Microstructural characteristics of Hastelloy X produced by Selective Laser Melting have been investigated by various microscopic techniques in the as built (AB) condition and after hot isostatic pressing (HIP). At sub-grain level the AB material consists of columnar high density dislocation cells while the HIP sample consists of columnar sub-grains with lower dislocation density that originate from the original dislocation cells, contradicting existing models. The sub-grains contain nanoscale precipitates enriched in Al, Ti, Cr and O, located at sub-grain boundaries in the AB condition and within the grains after HIP. At some grain boundaries, micrometer sized chromium carbides are detected after HIP. Micro hardness within the grains was found to decrease after HIP, which was attributed to the decrease in dislocation density due to recovery annealing. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000472696900040 |
Publication Date |
2019-05-21 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1044-5803 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.714 |
Times cited |
2 |
Open Access |
Not_Open_Access |
|
| |
Notes |
S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine and financial support. This work was also made possible through the AUHA13009 grant “TopSPIN for TEM nanostatistics” of the Flemish HERCULES foundation. |
Approved |
Most recent IF: 2.714 |
|
| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:159974 |
Serial |
5178 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Khalilov, U.; Vets, C.; Neyts, E.C. |
|
| |
Title |
Catalyzed growth of encapsulated carbyne |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
|
| |
Volume |
153 |
Issue |
|
Pages |
1-5 |
|
| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Carbyne is a novel material of current interest in nanotechnology. As is typically the case for nanomaterials, the growth process determines the resulting properties. While endohedral carbyne has been successfully synthesized, its catalyst and feedstock-dependent growth mechanism is still elusive. We here study the nucleation and growth mechanism of different carbon chains in a Ni-containing double walled carbon nanotube using classical molecular dynamics simulations and first-principles calculations. We find that the understanding the competitive role of the metal catalyst and the hydrocarbon is important to control the growth of 1-dimensional carbon chains, including Ni or H-terminated carbyne. Also, we find that the electronic property of the Ni-terminated carbyne can be tuned by steering the H concentration along the chain. These results suggest catalyst-containing carbon nanotubes as a possible synthesis route for carbyne formation. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000485054200001 |
Publication Date |
2019-07-01 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0008-6223 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.337 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
Fund of Scientific Research Flanders (FWO), Belgium, 12M1318N 1S22516N ; Flemish Supercomputer Centre VSC; Hercules Foundation; Flemish Government; University of Antwerp; The authors gratefully acknowledge the financial support from the Fund of Scientific Research Flanders (FWO), Belgium, Grant numbers 12M1318N and 1S22516N. The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. |
Approved |
Most recent IF: 6.337 |
|
| |
Call Number |
PLASMANT @ plasmant @c:irua:160695 |
Serial |
5187 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Vanderkerckhove, T.G.L.; Kerckhof, F.-M.; De Mulder, C.; Vlaeminck, S.E.; Boon, N. |
|
| |
Title |
Determining stoichiometry and kinetics of two thermophilic nitrifying communities as a crucial step in the development of thermophilic nitrogen removal |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Water research |
Abbreviated Journal |
|
|
| |
Volume |
156 |
Issue |
|
Pages |
34-45 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
Nitrification and denitrification, the key biological processes for thermophilic nitrogen removal, have separately been established in bioreactors at 50 °C. A well-characterized set of kinetic parameters is essential to integrate these processes while safeguarding the autotrophs performing nitrification. Knowledge on thermophilic nitrifying kinetics is restricted to isolated or highly enriched batch cultures, which do not represent bioreactor conditions. This study characterized the stoichiometry and kinetics of two thermophilic (50 °C) nitrifying communities. The most abundant ammonia oxidizing archaea (AOA) were related to the Nitrososphaera genus, clustering relatively far from known species Nitrososphaera gargensis (95.5% 16S rRNA gene sequence identity). The most abundant nitrite oxidizing bacteria (NOB) were related to Nitrospira calida (97% 16S rRNA gene sequence identity). The nitrification biomass yield was 0.200.24 g VSS g−1 N, resulting mainly from a high AOA yield (0.160.20 g VSS g−1 N), which was reflected in a high AOA abundance in the community (5776%) compared to NOB (511%). Batch-wise determination of decay rates (AOA: 0.230.29 d−1; NOB: 0.320.43 d−1) rendered an overestimation compared to in situ estimations of overall decay rate (0.0260.078 d−1). Possibly, the inactivation rate rather than the actual decay rate was determined in batch experiments. Maximum growth rates of AOA and NOB were 0.120.15 d−1 and 0.130.33 d−1 respectively. NOB were susceptible to nitrite, opening up opportunities for shortcut nitrogen removal. However, NOB had a similar growth rate and oxygen affinity (0.150.55 mg O2 L−1) as AOA and were resilient towards free ammonia (IC50 > 16 mg NH3-N L−1). This might complicate NOB outselection using common practices to establish shortcut nitrogen removal (SRT control; aeration control; free ammonia shocks). Overall, the obtained insights can assist in integrating thermophilic conversions and facilitate single-sludge nitrification/denitrification. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000466618400004 |
Publication Date |
2019-03-14 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0043-1354; 1879-2448 |
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:158226 |
Serial |
7798 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Boyat, X.; Ballat-Durand, D.; Marteau, J.; Bouvier, S.; Favergeon, J.; Orekhov, A.; Schryvers, D. |
|
| |
Title |
Interfacial characteristics and cohesion mechanisms of linear friction welded dissimilar titanium alloys: Ti–5Al–2Sn–2Zr–4Mo–4Cr (Ti17) and Ti–6Al–2Sn–4Zr–2Mo (Ti6242) |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Materials characterization |
Abbreviated Journal |
Mater Charact |
|
| |
Volume |
158 |
Issue |
|
Pages |
109942 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
A detailed microstructural examination endeavoring to understand the interfacial phenomena yielding to cohesion
in solid-state assembling processes was performed. This study focuses on the transition zone of a dissimilar
titanium alloy joint obtained by Linear Friction Welding (LFW) the β-metastable Ti17 to the near-α
Ti6242. The transition zone delimitating both alloys is characterized by a sharp microstructure change from
acicular HCP (Hexagonal Close-Packed) α′ martensitic laths in the Ti6242 to equiaxed BCC β (Body-Centered
Cubic) subgrains in the Ti17; these α′ plates were shown to precipitate within prior-β subgrains remarkably more
rotated than the ones formed in the Ti17. Both α′ and β microstructures were found to be intermingled within
transitional subgrains demarcating a limited gradient from one chemical composition to the other. These peculiar
interfacial grains revealed that the cohesive mechanisms between the rubbing surfaces occurred in the
single-phase β domain under severe strain and high-temperature conditions. During the hot deformation process,
the mutual migration of the crystalline interfaces from one material to another assisted by a continuous dynamic
recrystallization process was identified as the main adhesive mechanism at the junction zone. The latter led to
successful cohesion between the rubbing surfaces. Once the reciprocating motion stopped, fast cooling caused
both materials to experience either a βlean→α′ or βlean→βmetastable transformation in the interfacial zone depending
on their local chemical composition. The limited process time and the subsequent hindered chemical
homogenization at the transition zone led to retaining the so-called intermingled α’/βm subgrains constituting
the border between both Ti-alloys. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000503314000018 |
Publication Date |
2019-10-16 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1044-5803 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.714 |
Times cited |
|
Open Access |
|
|
| |
Notes |
The authors gratefully acknowledge the financial support of the French National Research Agency (ANR) through the OPTIMUM ANR- 14-CE27-0017 project. The authors would also like to thank the Hautsde- France Region and the European Regional Development Fund (ERDF) 2014/2020 for the co-funding of this work. The authors would also like to thank ACB for providing LFW samples as well as Airbus for their technical support. |
Approved |
Most recent IF: 2.714 |
|
| |
Call Number |
EMAT @ emat @c:irua:165084 |
Serial |
5441 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Grubova, I.Y.; Surmeneva, M.A.; Huygh, S.; Surmenev, R.A.; Neyts, E.C. |
|
| |
Title |
Effects of silicon doping on strengthening adhesion at the interface of the hydroxyapatite-titanium biocomposite : a first-principles study |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Computational materials science |
Abbreviated Journal |
Comp Mater Sci |
|
| |
Volume |
159 |
Issue |
159 |
Pages |
228-234 |
|
| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
In this paper we employ first-principles calculations to investigate the effect of substitutional Si doping in the amorphous calcium-phosphate (a-HAP) structure on the work of adhesion, integral charge transfer, charge density difference and theoretical tensile strengths between an a-HAP coating and amorphous titanium dioxide (a-TiO2) substrate systemically. Our calculations demonstrate that substitution of a P atom by a Si atom in a-HAP (a-Si-HAP) with the creation of OH-vacancies as charge compensation results in a significant increase of the bonding strength of the coating to the substrate. The work of adhesion of the optimized Si-doped interfaces reaches a value of up to -2.52 J m(-2), which is significantly higher than for the stoichiometric a-HAP/a-TiO2. Charge density difference analysis indicates that the dominant interactions at the interface have significant covalent character, and in particular two Ti-O and three Ca-O bonds are formed for a-Si-HAP/a-TiO2 and one Ti-O and three Ca-O bonds for a-HAP/a-TiO2. From the stress-strain curve, the Young's modulus of a-Si-HAP/a-TiO2 is calculated to be about 25% higher than that of the a-HAP/a-TiO2, and the yielding stress is about 2 times greater than that of the undoped model. Our calculations therefore demonstrate that the presence of Si in the a-HAP structure strongly alters not only the bioactivity and resorption rates, but also the mechanical properties of the a-HAP/a-TiO2 interface. The results presented here provide an important theoretical insight into the nature of the chemical bonding at the a-HAP/a-TiO2 interface, and are particularly significant for the practical medical applications of HAP-based biomaterials. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000457856900023 |
Publication Date |
2018-12-18 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0927-0256 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.292 |
Times cited |
1 |
Open Access |
Not_Open_Access |
|
| |
Notes |
|
Approved |
Most recent IF: 2.292 |
|
| |
Call Number |
UA @ admin @ c:irua:157480 |
Serial |
5272 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Wardenier, N.; Gorbanev, Y.; Van Moer, I.; Nikiforov, A.; Van Hulle, S.W.H.; Surmont, P.; Lynen, F.; Leys, C.; Bogaerts, A.; Vanraes, P. |
|
| |
Title |
Removal of alachlor in water by non-thermal plasma: Reactive species and pathways in batch and continuous process |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Water research |
Abbreviated Journal |
Water Res |
|
| |
Volume |
161 |
Issue |
|
Pages |
549-559 |
|
| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Pesticides are emerging contaminants frequently detected in the aquatic environment. In this work, a novel approach combining activated carbon adsorption, oxygen plasma treatment and ozonation was studied for the removal of the persistent chlorinated pesticide alachlor. A comparison was made between the removal efficiency and energy consumption for two different reactor operation modes: batchrecirculation and single-pass mode. The kinetics study revealed that the insufficient removal of alachlor by adsorption was significantly improved in terms of degradation efficiency and energy consumption when combined with the plasma treatment. The best efficiency (ca. 80% removal with an energy cost of 19.4 kWh mÀ3) was found for the single-pass operational mode of the reactor. In the batch-recirculating process, a complete elimination of alachlor by plasma treatment was observed after 30 min of treatment. Analysis of the reactive species induced by plasma in aqueous solutions showed that the decomposition of alachlor mainly occurred through a radical oxidation mechanism, with a minor contribution of long-living oxidants (O3, H2O2). Investigation of the alachlor oxidation pathways revealed six different oxidation mechanisms, including the loss of aromaticity which was never before reported for plasma-assisted degradation of aromatic pesticides. It was revealed that the removal rate and energy cost could be further improved with more than 50% by additional O3 gas bubbling in the solution reservoir. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000475999400054 |
Publication Date |
2019-06-10 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0043-1354 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.942 |
Times cited |
2 |
Open Access |
|
|
| |
Notes |
PlasmaTex project IWT, 1408/2 ; the European Marie Sklodowska-Curie Individual Fellowship within Horizon2020, 743151 ; Flemish Knowledge Centre Water; This work was financially supported by the PlasmaTex project IWT 1408/2 and the European Marie Sklodowska-Curie Individual Fellowship within Horizon2020 (‘LTPAM’, grant no. 743151). This research was initiated within the LED H2O project which is financially supported by the Flemish Knowledge Centre Water (Vlakwa). |
Approved |
Most recent IF: 6.942 |
|
| |
Call Number |
PLASMANT @ plasmant @c:irua:161173 |
Serial |
5288 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Tummers, A.; Wallert, A.; De Keyser, N. |
|
| |
Title |
Supplementing the eye : the technical analysis of Frans Hals's paintings – ii |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
The Burlington magazine |
Abbreviated Journal |
|
|
| |
Volume |
161 |
Issue |
1401 |
Pages |
996-1003 |
|
| |
Keywords |
A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
| |
Abstract |
The painting 'Two fisherboys' has long caused confusion among experts. A close comparison of the painting with a forgery by Han van Meegeren and Frans Hals's `Fisherboy' solves the conundrum and provides valuable insights into the merits and drawbacks of modern analytical techniques. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000500540400006 |
Publication Date |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0007-6287; 2044-9925 |
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:165106 |
Serial |
8624 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Miotti Bettanini, A.; Ding, L.; Mithieux, J.-D.; Parrens, C.; Idrissi, H.; Schryvers, D.; Delannay, L.; Pardoen, T.; Jacques, P.J. |
|
| |
Title |
Influence of M23C6 dissolution on the kinetics of ferrite to austenite transformation in Fe-11Cr-0.06C stainless steel |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
|
| |
Volume |
162 |
Issue |
|
Pages |
362-374 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The design of high-strength martensitic stainless steels requires an accurate control over the stability of undesired phases, like carbides and ferrite, which can hamper strength and ductility. Here, the ferrite to austenite transformation in Fe-11Cr-0.06C has been studied with a combined experimental-modelling approach. Experimental observations of the austenization process indicate that austenite growth proceeds in multiple steps, each one characterized by a different transformation rate. DICTRA based modelling reveals that the dissolution of the M23C6 Cr-rich carbides leads to Cr partitioning between austenite and parent phases, which controls the rate of transformation through (i) a soft-impingement effect and (ii) consequent stabilization of the ferrite, which remains untransformed inside chromium-enriched-zones even after prolonged austenization stage. Slow heating rate and smaller initial particle sizes allow the design of ferrite-free microstructure. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000454128400036 |
Publication Date |
2018-12-06 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0264-1275 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.364 |
Times cited |
3 |
Open Access |
OpenAccess |
|
| |
Notes |
The authors thank Professor Anne-Francoise Gourgues-Lorenzon and Helene Godin, Ecole Nationale Superiore des Mines de Paris (MINES ParisTech) for their fruitful discussions. AMB thanks Stijn Van den broek (Universiteit Antwerpen) for the skillful preparation of TEM samples with FIB. The financial support of CBMM (Companhia Brasileira de Metalurgia e Mineracao) is gratefully acknowledged. L. Delannay is mandated by the FNRS-Belgium. Computational resources have been provided by the supercomputing facilities of the UCLouvain (CISM/UCL) and the Consortium des Equipements de Calcul Intensif en Federation Wallonie Bruxelles (CÉCI) funded by the Fond de la Recherche Scientifique de Belgique (F.R.S.-FNRS) under convention 2.5020.11.; Cbmm; F.r.s.-fnrs, 2.5020.11 ; |
Approved |
Most recent IF: 4.364 |
|
| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:156721 |
Serial |
5161 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Cautaerts, N.; Delville, R.; Stergar, E.; Schryvers, D.; Verwerft, M. |
|
| |
Title |
Characterization of (Ti,Mo,Cr)C nanoprecipitates in an austenitic stainless steel on the atomic scale |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
164 |
Issue |
|
Pages |
90-98 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Nanometer sized (Ti,Mo,Cr)C (MX-type) precipitates that grew in a 24% cold worked Ti-stabilized austenitic stainless steel (grade DIN 1.4970, member of the 15-15Ti austenitic stainless steels) after heat treatment were fully characterized with transmission electron microscopy (TEM), probe corrected high angle annular dark field scanning transmission electron microscopy (HR-HAADF STEM), and atom probe tomography (APT). The precipitates shared the cube-on-cube orientation with the matrix and were facetted on {111} planes, yielding octahedral and elongated octahedral shapes. The misfit dislocations were believed to have Burgers vectors a/6<112> which was verified by geometrical phase analysis (GPA) strain mapping of a matrix-precipitate interface. The dislocations were spaced five to seven atomic
planes apart, on average slightly wider than expected for the lattice parameters of steel and TiC. Quantitative atom probe tomography analysis of the precipitates showed that precipitates were significantly enriched in Mo, Cr and V, and that they were hypostoichiometric with respect to C. These findings were consistent with a reduced lattice parameter. The precipitates were found primarily on Shockley
partial dislocations originating from the original perfect dislocation network. These novel findings could contribute to the understanding of how TiC nanoprecipitates interact with point defects and matrix dislocations. This is essential for the application of these Ti-stabilized steels in high temperature environments or fast spectrum nuclear fission reactors. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000456902800008 |
Publication Date |
2018-10-11 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
2 |
Open Access |
Not_Open_Access: Available from 12.10.2020
|
|
| |
Notes |
This work was supported by ENGIE [contract number 2015-AC- 007 e BSUEZ6900]; the U.S. Department of Energy, Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07- 051D14517 as part of a Nuclear Science User Facilities experiment; and by the MYRRHA program in development at SCKCEN, Belgium. Special thanks to Dr. H. Mezerji and Dr. T. Altantzis for the work on the FEI Titan microscope.We also want to thank Ms. J. Burns for the help on the FIB and Dr. Y. Wu at CAES for conducting the APT measurements. |
Approved |
Most recent IF: 5.301 |
|
| |
Call Number |
EMAT @ emat @c:irua:154873UA @ admin @ c:irua:154873 |
Serial |
5060 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Montero-Sistiaga, M.L.; Pourbabak, S.; Van Humbeeck, J.; Schryvers, D.; Vanmeensel, K. |
|
| |
Title |
Microstructure and mechanical properties of Hastelloy X produced by HP-SLM (high power selective laser melting) |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Materials & design |
Abbreviated Journal |
Mater Design |
|
| |
Volume |
165 |
Issue |
|
Pages |
107598 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
In order to increase the production rate during selective laser melting (SLM), a high power laser with a large beam diameter is used to build fully dense Hastelloy X parts. Compared to SLM with a low power and small diameter beam, the productivity was increased from 6 mm3/s to 16 mm3/s, i.e. 2.6 times faster. Besides the productivity benefit, the influence of the use of a high power laser on the rapid solidification microstructure and concomitant material properties is highlighted. The current paper compares the microstructure and tensile properties of Hastelloy X built with low and high power lasers. The use of a high power laser results in wider and shallower melt pools inducing an enhanced morphological and crystallographic texture along the building direction (BD). In addition, the increased heat input results in coarser sub-grains or high density dislocation walls for samples processed with a high power laser. Additionally, the influence of hot isostatic pressing (HIP) as a post-processing technique was evaluated. After HIP, the tensile fracture strain increased as compared to the strain in the as-built state and helped in obtaining competitive mechanical properties as compared to conventionally processed Hastelloy X parts. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000458259300020 |
Publication Date |
2019-01-09 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0264-1275 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.364 |
Times cited |
15 |
Open Access |
OpenAccess |
|
| |
Notes |
This research was supported by the ENGIE Research and Technology Division. The authors acknowledge ENGIE Research and Technology Division for the use of the SLM280HL machine. S.P. likes to thank the Flemish Science Foundation FWO for financial support under Project G.0366.15N. |
Approved |
Most recent IF: 4.364 |
|
| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:157469 |
Serial |
5176 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Charalampopoulou, E.; Cautaerts, N.; Van der Donck, T.; Schryvers, D.; Lambrinou, K.; Delville, R. |
|
| |
Title |
Orientation relationship of the austenite-to-ferrite transformation in austenitic stainless steels due to dissolution corrosion in contact with liquid Pb-Bi eutectic |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Scripta materialia |
Abbreviated Journal |
Scripta Mater |
|
| |
Volume |
167 |
Issue |
167 |
Pages |
66-70 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The orientation relationship of an austenite-to-ferrite phase transformation in 316L stainless steels induced by the loss of austenite stabilizers resulting from the steel dissolution corrosion in liquid Pb-Bi eutectic was studied by means of electron backscatter diffraction. The misorientations at the austenite/ferrite interface were compared to the prevailing orientation relationship models in steels. The Pitsch orientation relationship model was found to be predominant, which is unusual for austenite-to-ferrite bulk transformations in steels. The nature of this particular transformation, which involves loss of steel alloying elements and the presence of an interfacial liquid metal layer, is discussed to explain this finding. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000468720000014 |
Publication Date |
2019-04-06 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1359-6462 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.747 |
Times cited |
3 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; The authors would like to thank J. Joris (SCK center dot CEN) for technical support during corrosion testing, J. Lim (SCK center dot CEN) for the manufacture and calibration of the oxygen sensors used in this work and W. Van Renterghem (SCK center dot CEN) for his valuable help with the EBSD measurements. The steel suppliers were: Industeel, ArcelorMittal Group, for the 316L-SA plate, and Panchmahal Steel Ltd., India, for the 316L-CWrod. The authors gratefully acknowledge the financial support provided within the framework of the ongoing development of the MYRRHA irradiation facility. The research leading to these results falls within the framework of the European Energy Research Alliance Joint Programme on Nuclear Materials (EERA JPNM). ; |
Approved |
Most recent IF: 3.747 |
|
| |
Call Number |
UA @ admin @ c:irua:160228 |
Serial |
5257 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zhang, Z.; Rosalie, J.M.; Medhekar, N.V.; Bourgeois, L. |
|
| |
Title |
Resolving the FCC/HCP interfaces of the \gamma'(Ag2Al) precipitate phase in aluminium |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
174 |
Issue |
174 |
Pages |
116-130 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The gamma'(Ag2Al) phase in the Al-Ag alloy system has served as a textbook example for understanding phase transformations, precipitating hexagonal close-packed (HCP) crystals in the face-centred cubic (FCC) aluminium matrix. The gamma' precipitates display fully coherent interfaces at their broad facets and semicoherent interfaces at their edges. Shockley partial dislocations are expected to decorate the semicoherent interface due to the FCC-HCP structural transformation. Determining the exact locations and core structures of interfacial dislocations, however, remains challenging. In this study, we used aberration-corrected scanning transmission electron microscopy and atomistic simulations to re-visit this classical system. We characterised and explained the Ag segregation at coherent interfaces in the early stage of precipitation. For semicoherent interfaces, interfacial dislocations and reconstructions were revealed by bridging advanced microstructure characterisation and atomistic simulations. In particular, we discovered a new FCC/HCP interfacial structure that displays a unique combination of Shockley partial, Lomer-Cottrell and Hirth dislocations that evolve from the known interfacial structure purely composed by Shockley partial dislocations. Our findings show that the FCC-HCP transformation is more complex than hitherto considered, due to the interplay between structure and composition confined at interfaces. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000474501300011 |
Publication Date |
2019-05-18 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
3 |
Open Access |
|
|
| |
Notes |
; The authors acknowledge funding from the Australian Research Council (LE0454166, LE110100223), the Victorian State Government and Monash University for instrumentation, and use of the facilities within the Monash Centre for Electron Microscopy. LB and NM acknowledge the financial support of the Australian Research Council (DP150100558). The authors also gratefully acknowledge the computational support from Monash Advanced Research Computing Hybrid, the National Computational Infrastructure and Pawsey Supercomputing Centre. ZZ is thankful to Monash University for a Monash Graduate Scholarship, a Monash International Postgraduate Research Scholarship and a Monash Centre for Electron Microscopy Postgraduate Scholarship. ZZ is indebted to Matthew Weyland for his training in aberration-corrected electron microscopy, Scott Findlay for his help on image simulations, Xiang Gao for alloy casting and Ian Polmear for discussions. ; |
Approved |
Most recent IF: 5.301 |
|
| |
Call Number |
UA @ admin @ c:irua:161192 |
Serial |
5395 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Koch, K.; Samson, R.; Denys, S. |
|
| |
Title |
Aerodynamic characterisation of green wall vegetation based on plant morphology : an experimental and computational fluid dynamics approach |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Biosystems engineering |
Abbreviated Journal |
|
|
| |
Volume |
178 |
Issue |
|
Pages |
34-51 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
The installation of urban green infrastructure, particularly green walls, has proven to be an effective strategy for the mitigation of particulate matter (PM) pollution and the urban heat island effect. For the interaction between vegetation, PM and the local microclimate, wind flow is the main driving force. In order to investigate these interactions in detail, it is important to know how air flows through vegetation. This study proposes a method based on the DarcyForchheimer equation, where vegetation is considered as a porous medium and several plant species and the effects of plant morphological characteristics are examined both experimentally and using computer simulations. Results showed that the DarcyForchheimer model is a simple and robust way to describe air flow through vegetation regardless of its morphology. This research provides a new vision on studying aerodynamic properties of vegetation in relation to their morphology and provides opportunities for model the interaction between vegetation and its environment. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000456902300003 |
Publication Date |
2018-11-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1537-5110 |
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:155994 |
Serial |
7421 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Weng, Y.; Ding, L.; Zhang, Z.; Jia, Z.; Wen, B.; Liu, Y.; Muraishi, S.; Li, Y.; Liu, Q. |
|
| |
Title |
Effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloy |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
|
| |
Volume |
180 |
Issue |
180 |
Pages |
301-316 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The effect of Ag addition on the precipitation evolution and interfacial segregation for Al-Mg-Si alloys was systematically investigated by atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), atom probe tomography (APT) and density functional theory (DFT) calculation. At the early aging stage, Ag atoms could enter clusters and refine the distribution of these clusters. Then, Ag atoms preferentially segregate at the GP zone/alpha-Al and beta ''/alpha-Al interfaces at the peak aging stage by the replacement of Al atoms in FCC matrix. With prolonging aging time, Ag atoms generally incorporate into the interior of beta '' precipitate, facilitating the formation of QP lattice (a hexagonal network of Si atomic columns) and the local symmetry substructures, Ag sub-unit (1) and Ag sub-unit (2). At the over-aged stage, the Ag sub-unit (1) and Ag sub-unit (2) could transform to the beta'(Ag) (i.e. beta'(Ag1) and beta'(Ag2).) and Q'(Ag) unit cells, respectively. All the precipitates at the over-aging stage have a composite and disordered structure due to the coexistence of different unit cells (beta'(Ag1), beta'(Ag2), Q'(Ag) and beta') and the non-periodic arrangement of Ag atoms within the precipitate. In the equilibrium stage, the incorporated Ag atoms in the precipitates release into the alpha-Al matrix as solute atoms or form Ag particles. In general, Ag atoms undergo a process of “segregate at the precipitate/matrix interface -> incorporate into the interior of precipitate -> release into the alpha-Al matrix” during the precipitation for Al-Mg-Si-Ag alloys. Besides, Ag segregation is found at the interfaces of almost all metastable phases (including GP zone, beta '', beta'/beta'(Ag) phase) in Al-Mg-Si-Ag alloys. The Ag segregation at the beta'/alpha-Al interface could increase the length/diameter ratio of beta' phase and thus promote the additional strengthening potential of these alloys. These findings provide a new route for precipitation hardening by promoting the nucleation and morphology evolution of precipitates. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000495519100028 |
Publication Date |
2019-09-12 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
5.301 |
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 5.301 |
|
| |
Call Number |
UA @ admin @ c:irua:164641 |
Serial |
6295 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Pennycook, T.J.; Martinez, G.T.; Nellist, P.D.; Meyer, J.C. |
|
| |
Title |
High dose efficiency atomic resolution imaging via electron ptychography |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
196 |
Issue |
196 |
Pages |
131-135 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Radiation damage places a fundamental limitation on the ability of microscopy to resolve many types of materials at high resolution. Here we evaluate the dose efficiency of phase contrast imaging with electron ptychography. The method is found to be far more resilient to temporal incoherence than conventional and spherical aberration optimized phase contrast imaging, resulting in significantly greater clarity at a given dose. This robustness is explained by the presence of achromatic lines in the four dimensional ptychographic dataset. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000451180800018 |
Publication Date |
2018-10-18 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.843 |
|
| |
Call Number |
UA @ admin @ c:irua:165939 |
Serial |
6301 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Susi, T.; Madsen, J.; Ludacka, U.; Mortensen, J.J.; Pennycook, T.J.; Lee, Z.; Kotakoski, J.; Kaiser, U.; Meyer, J.C. |
|
| |
Title |
Efficient first principles simulation of electron scattering factors for transmission electron microscopy |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
197 |
Issue |
197 |
Pages |
16-22 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Electron microscopy is a powerful tool for studying the properties of materials down to their atomic structure. In many cases, the quantitative interpretation of images requires simulations based on atomistic structure models. These typically use the independent atom approximation that neglects bonding effects, which may, however, be measurable and of physical interest. Since all electrons and the nuclear cores contribute to the scattering potential, simulations that go beyond this approximation have relied on computationally highly demanding all-electron calculations. Here, we describe a new method to generate ab initio electrostatic potentials when describing the core electrons by projector functions. Combined with an interface to quantitative image simulations, this implementation enables an easy and fast means to model electron scattering. We compare simulated transmission electron microscopy images and diffraction patterns to experimental data, showing an accuracy equivalent to earlier all-electron calculations at a much lower computational cost. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000456311700003 |
Publication Date |
2018-11-12 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.843 |
Times cited |
3 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.843 |
|
| |
Call Number |
UA @ admin @ c:irua:165938 |
Serial |
6296 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Fatermans, J.; Van Aert, S.; den Dekker, A.J. |
|
| |
Title |
The maximum a posteriori probability rule for atom column detection from HAADF STEM images |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
201 |
Issue |
|
Pages |
81-91 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
|
| |
Abstract |
Recently, the maximum a posteriori (MAP) probability rule has been proposed as an objective and quantitative method to detect atom columns and even single atoms from high-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images. The method combines statistical parameter estimation and model-order selection using a Bayesian framework and has been shown to be especially useful for the analysis of the structure of beam-sensitive nanomaterials. In order to avoid beam damage, images of such materials are usually acquired using a limited incoming electron dose resulting in a low contrast-to-noise ratio (CNR) which makes visual inspection unreliable. This creates a need for an objective and quantitative approach. The present paper describes the methodology of the MAP probability rule, gives its step-by-step derivation and discusses its algorithmic implementation for atom column detection. In addition, simulation results are presented showing that the performance of the MAP probability rule to detect the correct number of atomic columns from HAADF STEM images is superior to that of other model-order selection criteria, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Moreover, the MAP probability rule is used as a tool to evaluate the relation between STEM image quality measures and atom detectability resulting in the introduction of the so-called integrated CNR (ICNR) as a new image quality measure that better correlates with atom detectability than conventional measures such as signal-to-noise ratio (SNR) and CNR. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000466343800009 |
Publication Date |
2019-02-04 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
OpenAccess |
|
| |
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (No. W.O.010.16N, No. G.0368.15N, No. G.0502.18N). This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant Agreement No. 770887). |
Approved |
Most recent IF: 2.843 |
|
| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:157176 |
Serial |
5153 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
van den Bos, K.H.W.; Janssens, L.; De Backer, A.; Nellist, P.D.; Van Aert, S. |
|
| |
Title |
The atomic lensing model: new opportunities for atom-by-atom metrology of heterogeneous nanomaterials |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
203 |
Issue |
|
Pages |
155 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The atomic lensing model has been proposed as a promising method facilitating atom-counting in heterogeneous nanocrystals [1]. Here, image simulations will validate the model, which describes dynamical diffraction as a superposition of individual atoms focussing the incident electrons. It will be demonstrated that the model is reliable in the annular dark field regime for crystals having columns containing dozens of atoms. By using the principles of statistical detection theory, it will be shown that this model gives new opportunities for detecting compositional differences. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000465021000020 |
Publication Date |
2018-12-06 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.843 |
Times cited |
4 |
Open Access |
OpenAccess |
|
| |
Notes |
The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0369.15N, G.0502.18N and WO.010.16N), and by personal grants to K.H.W. van den Bos and A. De Backer. This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (grant agreement No. 770887). |
Approved |
Most recent IF: 2.843 |
|
| |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:155721 |
Serial |
5074 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Müller-Caspary, K.; Krause, F.F.; Winkler, F.; Béché, A.; Verbeeck, J.; Van Aert, S.; Rosenauer, A. |
|
| |
Title |
Comparison of first moment STEM with conventional differential phase contrast and the dependence on electron dose |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
203 |
Issue |
203 |
Pages |
95-104 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
This study addresses the comparison of scanning transmission electron microscopy (STEM) measurements of momentum transfers using the first moment approach and the established method that uses segmented annular detectors. Using an ultrafast pixelated detector to acquire four-dimensional, momentum-resolved STEM signals, both the first moment calculation and the calculation of the differential phase contrast (DPC) signals are done for the same experimental data. In particular, we investigate the ability to correct the segment-based signal to yield a suitable approximation of the first moment for cases beyond the weak phase object approximation. It is found that the measurement of momentum transfers using segmented detectors can approach the first moment measurement as close as 0.13 h/nm in terms of a root mean square (rms) difference in 10 nm thick SrTiO3 for a detector with 16 segments. This amounts to 35% of the rms of the momentum transfers. In addition, we present a statistical analysis of the precision of first moment STEM as a function of dose. For typical experimental settings with recent hardware such as a Medipix3 Merlin camera attached to a probe-corrected STEM, we find that the precision of the measurement of momentum transfers stagnates above certain doses. This means that other instabilities such as specimen drift or scan noise have to be taken into account seriously for measurements that target, e.g., the detection of bonding effects in the charge density. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000465021000013 |
Publication Date |
2018-12-30 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.843 |
Times cited |
25 |
Open Access |
OpenAccess |
|
| |
Notes |
; The direct electron detector (Medipix3 Merlin) was funded by the Hercules fund from the Flemish Government. K. Muller-Caspary acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the framework of the Helmholtz Young Investigator Group moreSTEM (VH-NG-1317) at Forschungszentrum Julich, Germany. F. F. Krause acknowledges funding from the Central Research Development Fund of the University of Bremen, Germany. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) and the Research Fund of the University of Antwerp. ; |
Approved |
Most recent IF: 2.843 |
|
| |
Call Number |
UA @ admin @ c:irua:160213 |
Serial |
5242 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Leuthner, G.T.; Hummel, S.; Mangler, C.; Pennycook, T.J.; Susi, T.; Meyer, J.C.; Kotakoski, J. |
|
| |
Title |
Scanning transmission electron microscopy under controlled low-pressure atmospheres |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
|
| |
Volume |
203 |
Issue |
203 |
Pages |
76-81 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Transmission electron microscopy (TEM) is carried out in vacuum to minimize the interaction of the imaging electrons with gas molecules while passing through the microscope column. Nevertheless, in typical devices, the pressure remains at 10(-7) mbar or above, providing a large number of gas molecules for the electron beam to crack, which can lead to structural changes in the sample. Here, we describe experiments carried out in a modified scanning TEM (STEM) instrument, based on the Nion UltraSTEM 100. In this instrument, the base pressure at the sample is around 2 x 10(-10 )mbar, and can be varied up to 10(-6) mbar through introduction of gases directly into the objective area while maintaining atomic resolution imaging conditions. We show that air leaked into the microscope column during the experiment is efficient in cleaning graphene samples from contamination, but ineffective in damaging the pristine lattice. Our experiments also show that exposure to O(2 )and H2O lead to a similar result, oxygen providing an etching effect nearly twice as efficient as water, presumably due to the two 0 atoms per molecule. H(2 )and N-2 environments have no influence on etching. These results show that the residual gas environment in typical TEM instruments can have a large influence on the observations, and show that chemical etching of carbon-based structures can be effectively carried out with oxygen. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000465021000010 |
Publication Date |
2019-02-04 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.843 |
Times cited |
4 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.843 |
|
| |
Call Number |
UA @ admin @ c:irua:165937 |
Serial |
6321 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Castanheiro, A.; Joos, P.; Wuyts, K.; De Wael, K.; Samson, R. |
|
| |
Title |
Leaf-deposited semi-volatile organic compounds (SVOCs) : an exploratory study using GCxGC-TOFMS on leaf washing solutions |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Chemosphere |
Abbreviated Journal |
Chemosphere |
|
| |
Volume |
214 |
Issue |
214 |
Pages |
103-110 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
| |
Abstract |
Airborne particulate matter (PM) includes semi-volatile organic compounds (SVOCs), which can be deposited on vegetation matrices such as plant leaves. In alternative to air-point measurements or artificial passive substrates, leaf monitoring offers a cost-effective, time-integrating means of assessing local air quality. In this study, leaf washing solutions from ivy (Hedera hibernica) leaves exposed during one-month at different land use classes were explored via comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS). The composition of leaf-deposited SVOCs, corrected for those of unexposed leaves, was compared against routinely monitored pollutants concentrations (PM10, PM2.5, O3, NO2, SO2) measured at co-located air monitoring stations. The first study on leaf-deposited SVOCs retrieved from washing solutions, herein reported, delivered a total of 911 detected compounds. While no significant land use (rural, urban, industrial, traffic, mixed) effects were observed, increasing exposure time (from one to 28 days) resulted in a higher number and diversity of SVOCs, suggesting cumulative time-integration to be more relevant than local source variations between sites. After one day, leaf-deposited SVOCs were mainly due to alcohols, N-containing compounds, carboxylic acids, esters and lactones, while ketones, diketones and hydrocarbons compounds gained relevance after one week, and phenol compounds after one month. As leaf-deposited SVOCs became overall more oxidized throughout exposure time, SVOCs transformation or degradation at the leaf surface is suggested to be an important phenomenon. This study confirmed the applicability of GCxGC-TOFMS to analyze SVOCs from leaf washing solutions, further research should include validation of the methodology and comparison with atmospheric organic pollutants. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000449891300013 |
Publication Date |
2018-09-13 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0045-6535; 1879-1298 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.208 |
Times cited |
|
Open Access |
|
|
| |
Notes |
; The authors thank the Flemish Environment Agency (VMM) for their collaboration and air quality data; Sam Dekkers and Jonathan Van Waeyenbergh for their help with sample collection. The study was performed using a study set-up funded by the Special Research Fund of the University of Antwerp (KPBOF 2014, no. FFB 140090 'Tree leaf surface properties as dynamic drivers of particulate matter-leaf interaction and phyllosphere microbial communities'). A.C. acknowledges the Research Foundation Flanders (FWO) for her SB PhD fellowship. ; |
Approved |
Most recent IF: 4.208 |
|
| |
Call Number |
UA @ admin @ c:irua:153509 |
Serial |
5692 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Clima, S.; Garbin, D.; Devulder, W.; Keukelier, J.; Opsomer, K.; Goux, L.; Kar, G.S.; Pourtois, G. |
|
| |
Title |
Material relaxation in chalcogenide OTS SELECTOR materials |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Microelectronic engineering |
Abbreviated Journal |
Microelectron Eng |
|
| |
Volume |
215 |
Issue |
215 |
Pages |
110996 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Nature of the mobility-gap states in amorphous Ge-rich Ge50Se50 was found to be related to homopolar Ge bonds in the chains/clusters of Ge atoms. Threshold switching material suffers Ge-Ge bond concentration drift during material ageing, which can explain the observed reliability of the aGe(50)Se(50) selector devices. Strong Ge-N bonds were introduced to alleviate the observed instability. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000480665600008 |
Publication Date |
2019-05-21 |
|
| |
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 |
1.806 |
Times cited |
1 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 1.806 |
|
| |
Call Number |
UA @ admin @ c:irua:161905 |
Serial |
6308 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Van Winckel, T.; Liu, X.; Vlaeminck, S.E.; Takács, I.; Al-Omari, A.; Sturm, B.; Kjellerup, B.V.; Murthy, S.N.; De Clippeleir, H. |
|
| |
Title |
Overcoming floc formation limitations in high-rate activated sludge systems |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Chemosphere |
Abbreviated Journal |
|
|
| |
Volume |
215 |
Issue |
|
Pages |
342-352 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
High-rate activated sludge (HRAS) is an essential cornerstone of the pursuit towards energy positive sewage treatment through maximizing capture of organics. The capture efficiency heavily relies on the degree of solid separation achieved in the clarifiers. Limitations in the floc formation process commonly emerge in HRAS systems, with detrimental consequences for the capture of organics. This study pinpointed and overcame floc formation limitations present in full-scale HRAS reactors. Orthokinetic flocculation tests were performed with varying shear, sludge concentration, and coagulant or flocculant addition. These were analyzed with traditional and novel settling parameters and extracellular polymeric substances (EPS) measurements. HRAS was limited by insufficient collision efficiency and occurred because the solids retention time (SRT) was short and colloid loading was high. The limitation was predominantly caused by impaired flocculation rather than coagulation. In addition, the collision efficiency limitation was driven by EPS composition (low protein over polysaccharide ratio) instead of total EPS amount. Collision efficiency limitation was successfully overcome by bio-augmenting sludge from a biological nutrient removal reactor operating at long SRT which did not show any floc formation limitations. However, this action brought up a floc strength limitation. The latter was not correlated with EPS composition, but rather EPS amount and hindered settling parameters, which determined floc morphology. With this, an analysis toolkit was proposed that will enable design engineers and operators to tackle activated solid separation challenges found in HRAS systems and maximize the recovery potential of the process. (C) 2018 Elsevier Ltd. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000450383400038 |
Publication Date |
2018-10-01 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0045-6535; 1879-1298 |
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:153978 |
Serial |
8350 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chekol Zewdie, M.; Van Passel, S.; Cools, J.; Tenessa, D.B.; Ayele, Z.A.; Tsegaye, E.A.; Minale, A.S.; Nyssen, J. |
|
| |
Title |
Direct and indirect effect of irrigation water availability on crop revenue in northwest Ethiopia : a structural equation model |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Agricultural Water Management |
Abbreviated Journal |
Agr Water Manage |
|
| |
Volume |
220 |
Issue |
220 |
Pages |
27-35 |
|
| |
Keywords |
A1 Journal article; Economics; Engineering Management (ENM) |
|
| |
Abstract |
Development of a clear understanding of the relationship between the availability of dam-driven irrigation water and crop revenue is important in poverty reduction and food security process. As a result, large research efforts are devoted to understanding the relationship between the availability of irrigation water and crop revenue. However, earlier studies do have several limitations. For example, without considering its indirect effect, prior studies focused solely on the direct effect of availability of irrigation water on crop revue. In this study, using a structural equation model analysis, the direct and indirect effect of availability of dam-driven irrigation water on crop revenue is decomposed and quantified specifically for the Koga irrigation scheme, located in the Mecha district of Amhara region in Ethiopia. A primary data set was collected from a randomly selected sample of 450 households in the Koga irrigation scheme. More than half of the households (254) are supported by the Koga Dam irrigation water during the dry season, and the other 196 households depended only on rainfall. The results of the study showed that, in addition to its direct effect, the availability of irrigation water indirectly affected crop revenue through receptivity of the farmers to use modern farm inputs. Around 27 percent of the total effect of dam-driven irrigation water on crop revenue was mediated by farmers’ receptivity to use yield-enhancing modern farm inputs. The results of this study suggested that the availability of irrigation water is essential to improve both crop revenue and receptivity of the farmers to use modern farm inputs. This finding also drives a strategic framework that the receptivity of the farmers to use modern farm inputs is crucial for utilizing the positive effects of irrigation water availability on crop revenue. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000470941300003 |
Publication Date |
2019-04-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0378-3774 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
2.848 |
Times cited |
1 |
Open Access |
|
|
| |
Notes |
; The authors would like to thank Bahir Dar University – Institutional University Cooperation (BDU-IUC) VLIR_UOS project for providing us enough funds for the completion of this study. Special gratitude is given to Abrehet Kahassay and Kassahun Birhanu for helping us to map the study area; and to the data collectors (Hilemichael Fentahun, Etsehewot Birara, and Tsegachewu Degu) for their commitment. The authors gratefully acknowledge the Koga Irrigation Scheme office managers, Tewachewu Abebe, and his colleagues for their support during the data collection. The authors also acknowledge the farmers (respondents) for their willingness to spend time responding honestly to questions. ; |
Approved |
Most recent IF: 2.848 |
|
| |
Call Number |
UA @ admin @ c:irua:159246 |
Serial |
6182 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Quaglia, G.; Joris, I.; Broekx, S.; Desmet, N.; Koopmans, K.; Vandaele, K.; Seuntjens, P. |
|
| |
Title |
A spatial approach to identify priority areas for pesticide pollution mitigation |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Journal of environmental management |
Abbreviated Journal |
|
|
| |
Volume |
246 |
Issue |
|
Pages |
583-593 |
|
| |
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
Identifying priority areas is an essential step in developing management strategies to reduce pesticide loads in surface water. A spatially explicit model-based approach was developed to detect priority areas for diffuse pesticide pollution at catchment scale. The method uses available datasets and considers different pesticide pathways in the environment post-application. The approach was applied in a catchment area in SE Flanders (Belgium) as a case study. Calculated risk areas were obtained using detailed landscape data and combining pesticide emissions and hydrological connectivity. The risk areas obtained were further compared with an alternative observation-based method, developed specifically for this study site that includes long-term field observations and local expert knowledge. Both methods equally classified 50% of the areas. The impact of crop rotation on the calculated risk was analysed. High-risk areas were identified and added to a cumulative map over all five years to evaluate temporal variations. The model-based approach was used for the initial identification of risk areas at the study site. The tool helps to prioritise zones and detect particular fields to target landscape mitigation measures to reduce diffuse pesticide pollution reaching surface water bodies. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000482246700058 |
Publication Date |
2019-06-13 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0301-4797 |
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:162789 |
Serial |
7398 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zeng, C.Y.; Cao, S.; Li, Y.Y.; Zhao, Z.X.; Yao, X.Y.; Ma, X.; Zhang, X.P. |
|
| |
Title |
A hidden single-stage martensitic transformation from B2 parent phase to B19 ' martensite phase in an aged Ni51Ti49 alloy |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Materials letters |
Abbreviated Journal |
Mater Lett |
|
| |
Volume |
253 |
Issue |
253 |
Pages |
99-101 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The aged Ni-rich NiTi shape memory alloys (SMAs) exhibit the multi-stage martensitic transformation (MMT), which has important influences on functional properties and practical applications of the NiTi SMAs. A hidden single-stage martensitic transformation from B2 parent phase to B19' martensite phase is found in an aged Ni51Ti49 alloy, which happens concurrently with a commonly observed two-stage martensitic transformation B2-R-B19' (R: martensite phase) and actually composes one stage of a multi-stage martensitic transformation (MMT) together with the two-stage one. B2-B19' martensitic transformation occurs in the NiTi matrix containing Ni4Ti3 precipitates with relatively large inter-particle space, while B2-R-B19' transformation takes place in the NiTi matrix with Ni4Ti3 precipitates having relatively small inter-particle space. (C) 2019 Elsevier B.V. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000482629500025 |
Publication Date |
2019-06-17 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0167-577x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.572 |
Times cited |
|
Open Access |
|
|
| |
Notes |
; This work was supported by the Natural Science Foundation of Guangdong Province under Grant Nos. 2018B0303110012 and 2017A030313323, and the National Natural Science Foundation of China under Grant Nos. 51401081 and 51571092. ; |
Approved |
Most recent IF: 2.572 |
|
| |
Call Number |
UA @ admin @ c:irua:162764 |
Serial |
5381 |
|
| Permanent link to this record |
