|
“Liquid treatment with a plasma jet surrounded by a gas shield: effect of the treated substrate and gas shield geometry on the plasma effluent conditions”. Heirman P, Verloy R, Baroen J, Privat-Maldonado A, Smits E, Bogaerts A, Journal of physics: D: applied physics 57, 115204 (2024). http://doi.org/10.1088/1361-6463/ad146b
Abstract: The treatment of a well plate by an atmospheric pressure plasma jet is common for<italic>in vitro</italic>plasma medicine research. Here, reactive species are largely produced through the mixing of the jet effluent with the surrounding atmosphere. This mixing can be influenced not only by the ambient conditions, but also by the geometry of the treated well. To limit this influence and control the atmosphere, a shielding gas is sometimes applied. However, the interplay between the gas shield and the well geometry has not been investigated. In this work, we developed a 2D-axisymmetric computational fluid dynamics model of the kINPen plasma jet, to study the mixing of the jet effluent with the surrounding atmosphere, with and without gas shield. Our computational and experimental results show that the choice of well type can have a significant influence on the effluent conditions, as well as on the effectiveness of the gas shield. Furthermore, the geometry of the shielding gas device can substantially influence the mixing as well. Our results provide a deeper understanding of how the choice of setup geometry can influence the plasma treatment, even when all other operating parameters are unchanged.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Center for Oncological Research (CORE)
Impact Factor: 3.4
DOI: 10.1088/1361-6463/ad146b
|
|
|
“Determination of scandium in high-purity titanium using inductively coupled plasma mass spectrometry and glow discharge mass spectrometry as part of its certification as a reference material”. Held A, Taylor P, Ingelbrecht C, de Bièvre P, Broekaert J, van Straaten M, Gijbels R, Journal of analytical atomic spectrometry 10, 849 (1995). http://doi.org/10.1039/ja9951000849
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.466
Times cited: 6
DOI: 10.1039/ja9951000849
|
|
|
“Spatial monitoring of organohalogen compounds in surface water and sediments of a rural-urban river basin in Tanzania”. Hellar-Kihampa H, De Wael K, Lugwisha E, Govindan M, Covaci A, Van Grieken R, The science of the total environment 447, 186 (2013). http://doi.org/10.1016/J.SCITOTENV.2012.12.083
Abstract: The presence of persistent organic pollutants in Tanzanian environment is not well monitored despite the existing pollution potential from a number of sources. In this study, we investigated for the first time, the concentration profiles of different organohalogen compounds such as organochlorine pesticide residues (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in environmental samples (water and sediments) from the Pangani river basin (PRB). The PRB is one of the largest drainage basins in Tanzania, with its watershed exposed to multiple input sources of trace organic contaminants. Surface water and sediments were sampled from 12 representative stations of diverse characteristics and land-use practices, in three distinct seasons, and extracted by liquidliquid and Soxhlet extraction methods, respectively. Water samples were analyzed by GC-ECD for OCPs only, while sediment samples were analyzed for OCPs, PCBs and PBDEs by GC/MS. Seven compounds, dominated by HCH isomers (5104460 pg/L) and DDT analogs (1601460 pg/L),were detected in the water samples. These concentrations are far below the WHO guidelines for drinking water quality. A total of 42 compounds (8 OCPs, 28 PCB congeners and 6 PBDE congeners) were detected in the sediment samples. Their respective total concentration ranges were 24510,230; 35711,000 and 382175 pg/g dry weight. The spatial distribution patterns and Hierarchical Cluster Analysis reflected the impact of historical agricultural usage in sugarcane plantations (OCPs), and urbanization (PCBs and PBDEs). Risk assessment using sediment quality guidelines indicated no ecotoxicological risks. The results we have found provide preliminary data on levels of the organic contaminants in Pangani river basin as a new insight on the environmental quality of the area.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Impact Factor: 4.9
Times cited: 42
DOI: 10.1016/J.SCITOTENV.2012.12.083
|
|
|
“Water quality assessment in Pangani river basin, Tanzania : natural and anthropogenic influences on concentrations of nutrients and inorganic ions”. Hellar-Kihampa H, De Wael K, Lugwisha E, Van Grieken R, International journal of river basin management 11, 55 (2013). http://doi.org/10.1080/15715124.2012.759119
Abstract: The ongoing rapid expansions of human activities and population dynamics have potential impact on the environmental quality of the Pangani river basin, one of the largest water resources in Tanzania, including possible loadings of different kinds of micro-contaminants. However, specific extents of the impacts are rather not well investigated. In this work, we assessed the environmental quality of the basin, based on seasonal characterisation of physicochemical water and sediments parameters, dissolved inorganic ions and nutrient loads. The contributions of geochemical processes and land-use practices were evaluated by multivariate correlations and principal component analysis (PCA). Hierarchical cluster analysis was used to classify similar water quality stations and identify the most and least enriched ones. Surface waters were slightly alkaline, characterised by low total dissolved solids (48652 mg/L). Extremely low oxygen concentration (2.0 mg/L) was also a cause of concern at one station. The Na+ and HCO3 − ions provided the dominant cation and anion, respectively. PCA identified weathering of carbonate and Na+ bearing rocks, gypsum dissolution and atmospheric deposition of sea-salt as the major factors controlling the ionic composition, contributing more than 60% of the spatial variance. Concentration profiles of the chemical species showed a generally low level of anthropogenic inputs, except at a few locations where nitrate and nitrite were significantly enriched above the limits of safe exposure, with patterns indicating influences of farming and livestock keeping. A seasonal difference was observed, with lower ion concentrations during the rainy season, likely due to the dilution effect of increased water discharge. The study provides new insights into the environmental quality of the basin, and indicates the need for continuous monitoring and assessment of the chemical species in the area.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1080/15715124.2012.759119
|
|
|
“Concentration profiles of metal contaminants in fluvial sediments of a rural-urban drainage basin in Tanzania”. Hellar-Kihampa H, Potgieter-Vermaak S, De Wael K, Lugwisha E, van Espen P, Van Grieken R, International journal of environmental analytical chemistry 94, 77 (2014). http://doi.org/10.1080/03067319.2013.791976
Abstract: This study investigated concentration profiles of trace, rare earth and platinum group metals in fluvial sediments from the Pangani river basin (43,650 km2), one of the largest river basins in Tanzania, to assess its environmental quality. Sediment samples were collected in two distinct seasons from 12 representative sites of diverse land-use practices and characterised by ICP-MS after optimised microwave digestion. Ecological risks were assessed by evaluation of pollution index and comparison with legislated sediment quality guidelines (SQG). The results revealed contamination by some trace metals (e.g. Pb, V, Cu, Cr, Ni, Cd, As, Co, Mn and Zn) in concentrations ranging from 0.7 to 2940 mg kg−1, and four rare earth elements (Y, Ce, Nd, Yb) in concentrations ranging from 0.9 (Yb) to 500 mg kg−1 dry weight (Ce), which significantly exceeded the estimated background values at some stations. Palladium was the only platinum group element that was detected in quantifiable concentrations (0.33.5 mg kg−1). Concentrations of some trace metals exceeded the SQGs at some localised areas. Principal component analysis and multivariate correlations indicated geochemical characteristics of the area as the major control of metal concentrations and spatial variability. Organic matter and clay contents also played a significant role in metal distributions. Assessment of land-use practices upstream of the sampling locations was used to trace potential anthropogenic sources of metal enrichments, where highest levels were found in areas close to urban centres and agricultural activities. The study provides baseline data for future monitoring programs, and highlights the need for more comprehensive analysis involving a wider spatio-temporal scale and ecotoxicological risk assessment.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.208
Times cited: 5
DOI: 10.1080/03067319.2013.791976
|
|
|
“Elemental composition of bottom-sediments from Pangani river basin, Tanzania : lithogenic and anthropogenic sources”. Hellar-Kihampa H, Potgieter-Vermaak S, van Meel K, Gatto Rotondo G, Kishimba M, Van Grieken R, Toxicological and environmental chemistry 94, 525 (2012). http://doi.org/10.1080/02772248.2011.648940
Abstract: River-bed sediments from the Pangani basin, Tanzania, were characterized for elemental compositions, following contamination risks from rapid expansions of human activities in the area. Samples were collected during two individual seasons and analyzed by high-polarizing beam energy dispersive X-ray fluorescence (EDXRF) for eight major and 14 trace elements. Evaluation of enrichment factors (EFs) was used to investigate the elemental flux and assess the contributions of natural and anthropogenic influences. The abundances of the major elements followed the order Si > Al > Fe > Ca > K > Ti > Mn > P, similar to that of the upper earth's crust, and were generally from the weathering of the bed-rock. The high concentrations of typical anthropogenic trace-elements (Cr < 160 mg kg−1, V < 85 mg kg−1, Ni < 60 mg kg−1, Cu < 87 mg kg−1, La < 90 mg kg−1) coupled with high EFs (>2) in some locations indicated contamination associated with agricultural and industrial activities. Factor analysis extracted five principal components that contributed to 96.0% of the total observed variance. The results indicated that river-bed sediments of the Pangani basin were influenced to a larger extent by lithogenic sources than anthropogenic impacts.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1080/02772248.2011.648940
|
|
|
Hellemans K (2019) Laser ablation ICP-MS as a tool for surface analysis in comparison to other elemental analysis methods. 229 p
Abstract: Dit onderzoek presenteert een overzicht van de mogelijkheden van LA-ICP-MS als een techniek voor kwantitatieve analyse, bepalen van isotoopverhoudingen en elementaire beeldvorming. Hiervoor wordt de techniek zelf voorgesteld en worden de belangrijkste parameters die een invloed hebben op de kwaliteit van een LA-ICP-MS meting beschreven. Voor kwantitieve analyse worden de huidige calibratiestrategieën voor LA-ICP-MS toegelicht, zowel op het vlak van selectie en bereiding van standaarden als op het vlak van dataverwerking. Daarnaast werd een nieuwe calibratiestrategie voorgesteld, gebaseerd op een lineaire combinatie van standaarden. Een case study met de traditionele calibratiestrategie uit de literatuur werd uitgevoerd en vergeleken met data van SEM-EDX om een referentiekader te schetsen voor de performantie van de techniek. In een tweede case study werd onze nieuwe calibratiestrategie toegepast en werd er uitsluitend gebruik gemaakt van LA-ICP-MS, wat uitstekende resultaten opleverde. Met het oog op het bepalen van isotoopverhoudingen, werd er onderzocht wat de limieten zijn van het gebruik van een lage resolutie quadrupool massaspectrometer voor deze bepaling. Dit stelde ons in staat om de te verwachten accuraatheid en precisie in te schatten. De performantie bleek goed genoeg te zijn om weapon-grade plutonium te onderscheiden van global fall-out, zoals het werd aangetoond in de case study omtrent dit onderwerp. Uiteindelijk hebben we ook LA-ICP-MS geëvalueerd als een techniek voor elementaire beeldvorming, waarbij we tevens de meest courante multivariate data analyse hebben beschreven. Om de techniek te plaatsen tegenover andere elementaire technieken, werd een historisch verffragment geanalyseerd dat in het verleden reeds geanalyseerd was met SEM-EDX and μ-XRD. Op die manier konden we de resultaten accuraat vergelijken met de andere technieken.
Keywords: Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
|
|
“LA-ICP-MS labels early medieval Tuscan finds from Siena and Donoratico as late natron glass”. Hellemans K, Cagno S, Bogana L, Janssens K, Mendera M, Journal of Archaeological Science: Reports 23, 844 (2019). http://doi.org/10.1016/J.JASREP.2018.12.002
Abstract: The late antique/early medieval age in Central Italy is a well-suited context to verify the implications of the end of the natron glass supplies, and to explore the beginnings of the new plant-ash glass technology. We present the results of a LA-ICP-MS analysis campaign conducted on archaeological glass finds excavated at the Santa Maria della Scala hospital site in Siena and in Donoratico. This provided us with major, minor and trace element quantitative data for 49 glass samples belonging to drinking vessels and lamps, dated mainly between the 5th and the 8th century. On the basis of these data, we have sought to identify the working processes and possible glassware trade that are reflected in the glass composition. Major and minor element contents revealed that most samples, also at the later boundary of the explored timeframe, fit well within known late Roman glass classifications (e.g. HIMT, Levantine). Trace element analysis provided further information on the raw materials that were used in the glassmaking process, indicating the use of coastal sands as a silica source and allowing us to formulate different hypotheses on the materials used for the colouring process.
Keywords: A1 Journal article; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 3
DOI: 10.1016/J.JASREP.2018.12.002
|
|
|
“Composition and state of alteration of 18th-century glass finds found at the Cistercian nunnery of Clairefontaine, Belgium”. Hellemans K, Vincke A, Cagno S, Herremans D, De Clercq W, Janssens K, Journal of archaeological science 47, 121 (2014). http://doi.org/10.1016/J.JAS.2014.03.039
Abstract: A hundred 18th-century glass fragments were recovered at the Clairefontaine monastery in the Belgian province of Luxembourg. They were analysed by a combination of SEM-EDX and LA-ICP-MS in order to determine their major composition as well as their trace element signature. Multivariate statistical methods such as hierarchical clustering and principal component analysis were used to divide the glass fragments into four main groups: potassium-rich glass, sodium-rich glass, potassium/lime-rich glass and high-lime-low-alkali glass. Within every group, not only a similarity in composition is observed, but also in colour, morphology and deterioration patterns. Potash glass fragments are the most abundant and show extensive deterioration; two classes of potash glass were identified: one similar to certain Central European glass compositions, while the other one, characterised by large variations in potash: lime ratio, may be attributed to local (regional) glass production. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Philosophy; History; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.602
Times cited: 12
DOI: 10.1016/J.JAS.2014.03.039
|
|
|
“Reactions of high FeO-olivine rock with groundwater and redox-sensitive elements studied by surface-analytical methods and autoradiography”. Hellmuth KH, Siitari-Kaupi M, Rauhala E, Johansson B, Zilliacus R, Gijbels R, Adriaens A, Materials Research Society symposium proceedings 333, 947 (1994)
Keywords: P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Times cited: 6
|
|
|
“Infrared absorption in superlattices: a probe of the miniband dispersion and the structure of the impurity band”. Helm M, Hilber W, Fromherz T, Peeters FM, Alavi K, Pathak R, Physical review : B : condensed matter and materials physics 48, 1601 (1993). http://doi.org/10.1103/PhysRevB.48.1601
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 61
DOI: 10.1103/PhysRevB.48.1601
|
|
|
“Bloch and localized electrons in semiconductor superlattices”. Helm M, Hilber W, Fromherz T, Peeters FM, Alavi K, Pathak RN, Semiconductor science and technology 9, 1989 (1994). http://doi.org/10.1088/0268-1242/9/11S/022
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.19
Times cited: 1
DOI: 10.1088/0268-1242/9/11S/022
|
|
|
“Mini-band dispersion, critical points, and impurity bands in superlattices: an infrared absorption study”. Helm M, Hilber W, Fromherz T, Peeters FM, Alavi K, Pathak RN, Solid state electronics 37, 1277 (1994). http://doi.org/10.1016/0038-1101(94)90407-3
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.504
Times cited: 2
DOI: 10.1016/0038-1101(94)90407-3
|
|
|
“Minibands and Wannier-Strak ladders in semiconductor superlattices studied by infrared spectroscopy”. Helm M, Hilber W, Strasser G, de Meester R, Peeters FM, Brazilian journal of physics 29, 652 (1999)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.732
Times cited: 6
|
|
|
“Continuum Wannier-Stark ladders strongly interacting with Zener resonances in semiconductor superlattices”. Helm M, Hilber W, Strasser G, de Meester R, Peeters FM, Wacker A, Physical review letters 82, 3120 (1999). http://doi.org/10.1103/PhysRevLett.82.3120
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
Times cited: 34
DOI: 10.1103/PhysRevLett.82.3120
|
|
|
“Interminiband spectroscopy of biased superlattices”. Helm M, Hilber W, Strasser G, de Meester R, Peeters FM, Wacker A, Physica. E: Low-dimensional systems and nanostructures 7, 274 (2000). http://doi.org/10.1016/S1386-9477(99)00275-1
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 1
DOI: 10.1016/S1386-9477(99)00275-1
|
|
|
“Simultaneous investigation of vertical transport and intersubband absorption in a superlattice: continuum Wannier-Strak ladders and next-nearest neighbor tunneling”. Helm M, Hilber W, Strasser G, de Meester R, Peeters FM, Wacker A, Physica: B : condensed matter 272, 194 (1999). http://doi.org/10.1016/S0921-4526(99)00269-0
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.386
Times cited: 1
DOI: 10.1016/S0921-4526(99)00269-0
|
|
|
“Infrared-spectroscopy of subbands, minibands, and donors in GaAs/AlGaAs superlattices”. Helm M, Peeters FM, de Rosa F, Colas E, Harbison JP, Florez LT, Surface science : a journal devoted to the physics and chemistry of interfaces
T2 –, 9TH INTERNATIONAL CONF ON THE ELECTRONIC PROPERTIES OF TWO-DIMENSIONAL, SYSTEMS ( EP2DS-9 ) / 5TH INTERNATIONAL CONF ON MODULATED SEMICONDUCTOR, STRUCTURES ( MSS-5 ), JUL 263, 518 (1992). http://doi.org/10.1016/0039-6028(92)90400-Z
Abstract: A far-infrared absorption study of electrons in lightly-doped GaAs/Al0.3Ga0.7As superlattices is presented. Both weakly and strongly coupled superlattices are investigated, and the difference between intersubband transitions and transitions between extended minibands is demonstrated. At low temperatures, the absorption spectra are dominated by donor transitions. The 1s-2p(z) transition, which is intimately related to the intersubband transition, is observed. All experimental data are compared to an envelope function calculation for the miniband structure and a variational calculation for the donor energies. Excellent agreement between experiment and theory is achieved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.925
Times cited: 5
DOI: 10.1016/0039-6028(92)90400-Z
|
|
|
“Far-infrared spectroscopy of minibands and confined donors in GaAs/AlxGa1-xAs superlattices”. Helm M, Peeters FM, DeRosa F, Colas E, Harbison JP, Florez LT, Physical review : B : condensed matter and materials physics 43, 13983 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 77
|
|
|
“Infrared spectroscopy of subbands, minibands, and donors in GaAs/AlGaAs superlatices”. Helm M, Peeters FM, DeRosa F, Colas E, Harbison JP, Florez LT, Surface science 263, 518 (1992)
Keywords: A3 Journal article; Condensed Matter Theory (CMT)
Times cited: 5
|
|
|
“Measurement of the size of embedded metal clusters by mass spectrometry, transmission electron microscopy, and small-angle X-ray scattering”. Hendrich C, Favre L, Ievlev DN, Dobrynin AN, Bras W, Hörmann U, Piscopiello E, Van Tendeloo G, Lievens P, Temst K, Applied physics A : materials science &, processing 86, 533 (2007). http://doi.org/10.1007/s00339-006-3808-5
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.455
Times cited: 11
DOI: 10.1007/s00339-006-3808-5
|
|
|
Hendrickx M (2020) Study of the effect of cation substitution on the local structure and the properties of perovskites and Li-ion battery cathode materials. 208 p
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
|
|
|
“The influence of synthesis method on the local structure and electrochemical properties of Li-rich/Mn-rich NMC cathode materials for Li-Ion batteries”. Hendrickx M, Paulus A, Kirsanova MA, Van Bael MK, Abakumov AM, Hardy A, Hadermann J, Nanomaterials 12, 2269 (2022). http://doi.org/10.3390/NANO12132269
Abstract: Electrochemical energy storage plays a vital role in combating global climate change. Nowadays lithium-ion battery technology remains the most prominent technology for rechargeable batteries. A key performance-limiting factor of lithium-ion batteries is the active material of the positive electrode (cathode). Lithium- and manganese-rich nickel manganese cobalt oxide (LMR-NMC) cathode materials for Li-ion batteries are extensively investigated due to their high specific discharge capacities (>280 mAh/g). However, these materials are prone to severe capacity and voltage fade, which deteriorates the electrochemical performance. Capacity and voltage fade are strongly correlated with the particle morphology and nano- and microstructure of LMR-NMCs. By selecting an adequate synthesis strategy, the particle morphology and structure can be controlled, as such steering the electrochemical properties. In this manuscript we comparatively assessed the morphology and nanostructure of LMR-NMC (Li1.2Ni0.13Mn0.54Co0.13O2) prepared via an environmentally friendly aqueous solution-gel and co-precipitation route, respectively. The solution-gel (SG) synthesized material shows a Ni-enriched spinel-type surface layer at the {200} facets, which, based on our post-mortem high-angle annual dark-field scanning transmission electron microscopy and selected-area electron diffraction analysis, could partly explain the retarded voltage fade compared to the co-precipitation (CP) synthesized material. In addition, deviations in voltage fade and capacity fade (the latter being larger for the SG material) could also be correlated with the different particle morphology obtained for both materials.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.3
DOI: 10.3390/NANO12132269
|
|
|
“CaLa2FeCoSbO9 and ALa2FeNiSbO9 (A = Ca, Sr, Ba): cation-ordered, inhomogeneous, ferrimagnetic perovskites”. Hendrickx M, Tang Y, Hunter EC, Battle PD, Cadogan Jm, Hadermann J, Journal Of Solid State Chemistry 285, 121226 (2020). http://doi.org/10.1016/j.jssc.2020.121226
Abstract: Polycrystalline samples of CaLa2FeCoSbO9 and ALa2FeNiSbO9 (A=Ca, Sr, Ba) have been prepared in solid-state reactions and studied by a combination of transmission electron microscopy, magnetometry, X-ray diffraction, neutron diffraction and Mössbauer spectroscopy. Diffraction and TEM showed that each shows 1:1 B-site ordering in which Co2+/Ni2+ and Sb5+ tend to occupy two distinct crystallographic sites while Fe3+ is distributed over both sites. While X-ray and neutron diffraction agreed that all four compositions are monophasic with space group P21/n, TEM revealed different levels of compositional inhomogeneity at the subcrystal scale, which, in the case of BaLa2FeNiSbO9, leads to the occurrence of both a P21/n and an I2/m phase. Magnetometry and neutron diffraction show that these perovskites are ferrimagnets with a G-type magnetic structure. Their relatively low magnetisation can be attributed to their inhomogeneity. This work demonstrates the importance of studying the microstructure of complex compositions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.3
DOI: 10.1016/j.jssc.2020.121226
|
|
|
“Structural and magnetic properties of the perovskites A₂LaFe₂SbO₉, (A = Ca, Sr, Ba)”. Hendrickx M, Tang Y, Hunter EC, Battle PD, Hadermann J, Journal Of Solid State Chemistry 295, 121914 (2021). http://doi.org/10.1016/J.JSSC.2020.121914
Abstract: Polycrystalline samples of A(2)LaFe(2)SbO(9) (A = Ca, Sr, Ba) perovskites appeared monophasic to X-ray or neutron powder diffraction but a single-crystal study utilising transmission electron microscopy revealed a greater level of complexity. Although local charge balance is maintained, compositional and structural variations are present among and within the submicron-sized crystals. Despite the inhomogeneity, A = Ca is monophasic with a partially-ordered distribution of Fe3+ and Sb5+ cations across two crystallographically-distinct octahedral sites, i.e. Ca2La(Fe1.25Sb0.25)(2d) (Fe0.75Sb0.75)(2c)O-9. For A = Sr or Ba, the inhomogeneities result in differences in the filling patterns of the octahedra and the ordering of the B cations. Particles of A = Sr contain a phase (Fe:Sb similar to 2:1) without B cation ordering and one (Fe:Sb similar to 1:1) with B cation ordering. Monophasic A = Ba lacks long-range cation order although ordered nanodomains are present within the disordered phase. The temperature dependence of the magnetic properties of each sample is discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
DOI: 10.1016/J.JSSC.2020.121914
|
|
|
“Conservation of the Amsterdam sunflowers : from past to future”. Hendriks E, Geldof M, van den Berg KJ, Monico L, Miliani C, Moretti P, Iwanicka M, Targowski P, Megens L, de Groot S, van Keulen H, Janssens K, Vanmeert F, van der Snickt G page 175 (2019).
Abstract: This chapter lays out a conservation timeline, from past to future, for the Amsterdam version of Van Gogh's Sunflowers. It starts by considering the restoration history of the painting in order to assess its current physical state, and looks ahead to formulate an appropriate strategy for future conservation treatment and display. Due attention is paid to the two recorded episodes of restoration performed in 1927 and 1961 by the Dutch restorer, Jan Cornelis Traas. Based on physical and chemical investigation of Sunflowers we attempt to reconstruct what these former treatments (which are barely documented) entailed and consider the repercussions for the present condition of the painting. The former interventions by Traas also serve as a benchmark to reflect on current choices made, highlighting the extent to which ideas and methodologies have continued to evolve over the past century as conservation has moved further away from being a singularly craft-based activity to become an established historical and scientific discipline underpinned by ethical guidelines. Jan Cornelis Traas (1898–1984) As mentioned, the two main recorded interventions to the Amsterdam Sunflowers may be associated with the Dutch restorer, Jan Cornelis Traas, who treated the picture in 1927, close to the start of his career, and again in 1961, shortly before he retired. Traas was the first restorer to be appointed at the Mauritshuis in The Hague where he worked from 1931 to 1962 and treated hundreds of paintings, including iconic masterpieces such as Girl with a Pearl Earring by Johannes Vermeer. Yet despite the magnitude and importance of his restoration oeuvre, J.C. Traas (as he is usually referred to in surviving documents), has remained somewhat obscure. He is shown here in the only known surviving photograph of him at work, shortly before he retired (fig. 7.1). Unlike his illustrious contemporaries, A. Martin de Wild (1899–1969) and Helmut Ruhemann (1891–1973), for example, Traas did not publish anything, he appears to have kept no records of his work and no personal archive is known. However, the study of some newly discovered historical documents, combined with physical examination of Sunflowers and a large number of other works he treated, allows us to recover an idea of his working practices and approaches viewed within the context of his day.
Keywords: H1 Book chapter; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
DOI: 10.1017/9789048550531.008
|
|
|
“EFTEM study of plasma etched low-k Si-O-C dielectrics”. Hens S, Bender H, Donaton RA, Maex K, Vanhaelemeersch S, van Landuyt J, Institute of physics conference series
T2 –, Royal-Microscopical-Society Conference on Microscopy of Semiconducting, Materials, MAR 25-29, 2001, UNIV OXFORD, OXFORD, ENGLAND , 415 (2001)
Abstract: Materials with low dielectric constant ("low-k'') in combination with Cu metallization are replacing the oxide based dielectrics with Al metallization in future generations of micro-electronic devices. In this work, a carbon doped oxide low-k dielectric material is studied after different kinds of etch/strip steps in single damascene Cu. filled line structures. Interline capacitance measurements indicate a dependence of the dielectric constant on the strip conditions. EFTEM is used to study the composition of the dielectric material and the modification of the low-k material at the sidewall of the etched structures for the various treatment conditions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
|
|
|
“Quantitative EFTEM study of germanium quantum dots”. Hens S, Stuer C, Bender H, Loo R, van Landuyt J, , 345 (2001)
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
|
|
|
“Chemical and structural analysis of etching residue layers in semiconductor devices with energy filtering transmission electron microscopy”. Hens S, van Landuyt J, Bender H, Boullart W, Vanhaelemeersch S, Materials science in semiconductor processing 4, 109 (2001). http://doi.org/10.1016/S1369-8001(00)00147-5
Abstract: The use of an energy-filtering held emission gun transmission electron microscope (CM30 FEG Ultratwin) allows, apart from imaging morphologies down to nanometer scale, the fast acquisition of high-resolution element distributions. Electrons that have lost energy corresponding to characteristic inner-shell loss edges are used to form the element maps. The production of Ultra Large-Scale Integration (ULSI) devices with dimensions below 0.25 mum requires among others the formation of a multilayer metallization scheme by means of repeatedly applying the deposition and etching of dielectrics and metals. In this work the evolution of the surface chemical species on etched Al lines in a post-etch cleaning process has been investigated by energy filtering transmission electron microscopy, with the aim to understand the role of each process step on the removal of the etching residues. (C) 2001 Elsevier Science Ltd. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 2.359
DOI: 10.1016/S1369-8001(00)00147-5
|
|
|
“Producing photoluminescent species from Sp2 carbons”. Hens SC, Shenderova O, Turner S, Fullerenes, nanotubes, and carbon nanostructures 20, 502 (2012). http://doi.org/10.1080/1536383X.2012.655667
Abstract: The treatment of sp2 carbon materials, including micrographite, nanographite, HOPG, onion-like-carbon, and single-walled carbon nanotubes, in a 3:1 sulfuric to nitric acid mixture produced photoluminescent reaction solutions. These colloidal, aqueous solutions appeared photoluminescently stable under a UV lamp and ranged in color from red to blue. The photoluminescent wavelength shifted to shorter wavelength with increasing reaction time or increasing reaction temperature. Raman spectroscopy showed evidence of defect structures in graphitic residue, and transmission electron microscopy showed unusual structures present in the supernatant including graphitic balls.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 1.35
Times cited: 4
DOI: 10.1080/1536383X.2012.655667
|
|