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“How to monitor the progress towards a circular food economy : a Delphi study”. Van Schoubroeck S, Vermeyen V, Alaerts L, Van Acker K, Van Passel S, Sustainable Production and Consumption 32, 457 (2022). http://doi.org/10.1016/J.SPC.2022.05.006
Abstract: Within the food sector, the implementation of a circular economy (CE) can reduce resource consumption and emissions to the environment by moving away from a linear and unsustainable system. This necessitates a clear vision on what circularity for food means, which will provide a much-needed foundation to develop a mon-itoring tool that reveals insights into the progress being made towards a CE, and to expose the bottlenecks and opportunities. This research study contributes to the development of a shared vision for circularity within the food system, and defines and prioritizes a set of indicator themes to monitor a circular food economy (CFE). A two-round Delphi study was performed, including a brainstorming session with experts and the construction of a consensus ranking of indicator themes, considering the production and processing and the consumption stage. The Delphi results provide a shared vision on a CFE, and a blueprint for researchers and policy-makers on its monitoring, which will stimulate the progression from a linear to a circular system.(c) 2022 Published by Elsevier Ltd on behalf of Institution of Chemical Engineers.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM)
Impact Factor: 12.1
DOI: 10.1016/J.SPC.2022.05.006
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“The circular economy potential of reversible bonding in smartphones”. Parchomenko A, De Smet S, Pals E, Vanderreydt I, Van Opstal W, Sustainable Production and Consumption 41, 362 (2023). http://doi.org/10.1016/J.SPC.2023.08.017
Abstract: The increased use of adhesive bonding in manufacturing is an important barrier to implement circular economy strategies, including repair, refurbishment, and high-quality recycling. The circular economy potential of reversible adhesives that are debondable on demand, however, remains largely unexplored. In this paper we apply an integrated technology-agnostic framework to smartphones to identify and quantify the circular econ-omy potential of reversible bonding. In this framework we combine insights from Life Cycle Assessment, Life Cycle Costing, and Statistical Entropy Analysis. We find that reversible bonding of smartphones can be an enabler for circular strategies and have a considerable positive impact on preserving higher functionality on a product, component, and material level. The major added value of reversible bonding is its potential to replace and update parts, retaining the main environmental hotspot of a smartphone. Firms, however, will not likely switch to this technology, even though bonding and debonding make up only a small fraction of total lifecycle costs. Therefore, policy recommendations include mandatory policies on repairability and public procurement favouring the use of reversible bonding techniques. This would alter incentives in contexts where consumer preferences for lease markets cannot be taken for granted. The evaluation of different debonding scenarios from three distinct per-spectives provides a comprehensive, more reliable, and robust understanding of the trade-offs related to debonding and its potential contribution to the circular economy.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 12.1
DOI: 10.1016/J.SPC.2023.08.017
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“Using natural language processing to monitor circular activities and employment”. Borms L, Multani M, Bachus K, Dams Y, Brusselaers J, Van Passel S, Sustainable Production and Consumption 46, 42 (2024). http://doi.org/10.1016/J.SPC.2024.02.007
Abstract: In Europe, NACE codes are used for the official classification of sectors, however, the circular economy is not sufficiently captured in this classification. Therefore, this paper improves previous attempts for defining circular activities and jobs by web scraping techniques applied to each company in Belgium. We analyze their first, second, and third official NACE codes and compare these to the NACE codes they should have been allocated to according to the web scraping data. Subsequently, we calculate circularity scores for every sector to construct an indicator for the number of circular companies and jobs. The results show that the number of circular companies is lower than the baseline from official statistics when we only consider the companies' first and main NACE code. The estimates are higher than the baseline when we also take the second and third NACE codes into account and the estimated number of circular jobs is far higher than the baseline. This research upgrades previous classifications of circular sectors and demonstrates how web scraping and novel data might improve our understanding and capacity to build data. Based on the results in this paper, we recommend a uniform data collection such as reporting standards, and an inclusion of all circular strategies in sectoral classifications.
Keywords: A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM); Herman Deleeck Centre for Social Policy
Impact Factor: 12.1
DOI: 10.1016/J.SPC.2024.02.007
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“Evidence that supertriangles exist in nature from the vertical projections of Koelreuteria paniculata fruit”. Li Y, Quinn BK, Gielis J, Li Y, Shi P, Symmetry 14, 23 (2022). http://doi.org/10.3390/SYM14010023
Abstract: Many natural radial symmetrical shapes (e.g., sea stars) follow the Gielis equation (GE) or its twin equation (TGE). A supertriangle (three triangles arranged around a central polygon) represents such a shape, but no study has tested whether natural shapes can be represented as/are supertriangles or whether the GE or TGE can describe their shape. We collected 100 pieces of Koelreuteria paniculata fruit, which have a supertriangular shape, extracted the boundary coordinates for their vertical projections, and then fitted them with the GE and TGE. The adjusted root mean square errors (RMSEadj) of the two equations were always less than 0.08, and >70% were less than 0.05. For 57/100 fruit projections, the GE had a lower RMSEadj than the TGE, although overall differences in the goodness of fit were non-significant. However, the TGE produces more symmetrical shapes than the GE as the two parameters controlling the extent of symmetry in it are approximately equal. This work demonstrates that natural supertriangles exist, validates the use of the GE and TGE to model their shapes, and suggests that different complex radially symmetrical shapes can be generated by the same equation, implying that different types of biological symmetry may result from the same biophysical mechanisms.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.7
DOI: 10.3390/SYM14010023
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“A new program to estimate the parameters of Preston's equation, a general formula for describing the egg shape of birds”. Shi P, Wang L, Quinn BKK, Gielis J, Symmetry 15, 231 (2023). http://doi.org/10.3390/SYM15010231
Abstract: Preston's equation is a general model describing the egg shape of birds. The parameters of Preston's equation are usually estimated after re-expressing it as the Todd-Smart equation and scaling the egg's actual length to two. This method assumes that the straight line through the two points on an egg's profile separated by the maximum distance (i.e., the longest axis of an egg's profile) is the mid-line. It hypothesizes that the photographed egg's profile is perfectly bilaterally symmetrical, which seldom holds true because of photographic errors and placement errors. The existing parameter estimation method for Preston's equation considers an angle of deviation for the longest axis of an egg's profile from the mid-line, which decreases prediction errors to a certain degree. Nevertheless, this method cannot provide an accurate estimate of the coordinates of the egg's center, and it leads to sub-optimal parameter estimation. Thus, it is better to account for the possible asymmetry between the two sides of an egg's profile along its mid-line when fitting egg-shape data. In this paper, we propose a method based on the optimization algorithm (optimPE) to fit egg-shape data and better estimate the parameters of Preston's equation by automatically searching for the optimal mid-line of an egg's profile and testing its validity using profiles of 59 bird eggs spanning a wide range of existing egg shapes. We further compared this method with the existing one based on multiple linear regression (lmPE). This study demonstrated the ability of the optimPE method to estimate numerical values of the parameters of Preston's equation and provide the theoretical egg length (i.e., the distance between two ends of the mid-line of an egg's profile) and the egg's maximum breadth. This provides a valuable approach for comparing egg shapes among conspecifics or across different species, or even different classes (e.g., birds and reptiles), in future investigations.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.7
DOI: 10.3390/SYM15010231
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“Effects of the numerical values of the parameters in the Gielis equation on its geometries”. Wang L, Ratkowsky DA, Gielis J, Ricci PE, Shi P, Symmetry 14, 2475 (2022). http://doi.org/10.3390/SYM14122475
Abstract: The Lamé curve is an extension of an ellipse, the latter being a special case. Dr. Johan Gielis further extended the Lamé curve in the polar coordinate system by introducing additional parameters (n1, n2, n3; m): rφ=1Acosm4φn2+1Bsinm4φn3−1/n1, which can be applied to model natural geometries. Here, r is the polar radius corresponding to the polar angle φ; A, B, n1, n2 and n3 are parameters to be estimated; m is the positive real number that determines the number of angles of the Gielis curve. Most prior studies on the Gielis equation focused mainly on its applications. However, the Gielis equation can also generate a large number of shapes that are rotationally symmetric and axisymmetric when A = B and n2 = n3, interrelated with the parameter m, with the parameters n1 and n2 determining the shapes of the curves. In this paper, we prove the relationship between m and the rotational symmetry and axial symmetry of the Gielis curve from a theoretical point of view with the condition A = B, n2 = n3. We also set n1 and n2 to take negative real numbers rather than only taking positive real numbers, then classify the curves based on extremal properties of r(φ) at φ = 0, π/m when n1 and n2 are in different intervals, and analyze how n1, n2 precisely affect the shapes of Gielis curves.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.7
DOI: 10.3390/SYM14122475
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“Gielis transformations for the audiovisual geometry database”. Chapman D, Gielis J, Symmetry : culture and science 32, 177 (2021). http://doi.org/10.26830/SYMMETRY_2021_2_177
Abstract: This publication introduces the audiovisual geometry database with Gielis transformations as initial records for a prototype of the database. A concise overview is given of the rationale behind the database and studying wave phenomena with Gielis transformations. First results on a form of timbral polyphony observed in Gielis curves and future work are briefly discussed.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.26830/SYMMETRY_2021_2_177
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“Phi-bonacci in Ancient Greece”. Gielis J, Symmetry : culture and science 32, 25 (2021). http://doi.org/10.26830/SYMMETRY_2021_1_025
Abstract: Fibonacci numbers are a very popular subject in mathematics, culture and science. A major open question is why the ancient Greeks overlooked this series, while they were very familiar with the golden mean and division in extreme and mean ratio. Furthermore, they could compute the square root of five to a high degree of precision using Theon 's ladder. This fact is based on tables built with side and diagonal numbers, and it is a simple and incredibly efficient method to compute roots of integers, though it is little known even now among most of the experts. The biologist D 'Arcy Wentworth Thompson showed that the same method could be used to generate the Fibonacci series using a simple shift in the computation of the tables. He argues, quite convincingly, that the ancient Greeks could not have overlooked this. Actually, the same method can be used to generate all possible regular phyllotaxis patterns.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.26830/SYMMETRY_2021_1_025
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“The apeirogon and dual numbers”. Gielis J, Brasili S, Symmetry : culture and science 32, 157 (2021). http://doi.org/10.26830/SYMMETRY_2021_2_157
Abstract: The richness, diversity, connection, depth and pleasure of studying symmetry continue to open doors. Here we report a connection between Coxeter's Apeirogon and the geometry associated with pictorial space, parabolic rotation and dual numbers.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.26830/SYMMETRY_2021_2_157
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“Simon Stevin as a central figure in the development of abstract algebra and generic programming”. Gielis J, Symmetry : culture and science 34, 155 (2023). http://doi.org/10.26830/SYMMETRY_2023_2_155
Abstract: Simon Stevin (1548-1620) is mainly known for the decimal system and his Clootkrans proof. His influence is also profound in infinitesimal calculus, mechanics, and even in abstract algebra and today’s conception of polynomials, algorithms, and generic programming. Here we review his influence as assessed in generic programming. According to Dr. Stepanov, one of the most influential researchers in generic programming, Stevin’s work on polynomials can be regarded as the essence of generic programming: an algorithm from one domain can be applied in another similar domain.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.26830/SYMMETRY_2023_2_155
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Gielis J (2023) Fred Van Oystaeyen : Time hybrids: a new generic theory of reality. 347–351
Keywords: Review; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.26830/SYMMETRY_2023_3_357
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“The generalized Gielis geometric equation and its application”. Shi P, Ratkowsky DA, Gielis J, Symmetry-Basel 12, 645 (2020). http://doi.org/10.3390/SYM12040645
Abstract: Many natural shapes exhibit surprising symmetry and can be described by the Gielis equation, which has several classical geometric equations (for example, the circle, ellipse and superellipse) as special cases. However, the original Gielis equation cannot reflect some diverse shapes due to limitations of its power-law hypothesis. In the present study, we propose a generalized version by introducing a link function. Thus, the original Gielis equation can be deemed to be a special case of the generalized Gielis equation (GGE) with a power-law link function. The link function can be based on the morphological features of different objects so that the GGE is more flexible in fitting the data of the shape than its original version. The GGE is shown to be valid in depicting the shapes of some starfish and plant leaves.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.7
Times cited: 4
DOI: 10.3390/SYM12040645
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“Determination of spinel content in cycled Li1.2Ni0.13Mn0.54Co0.13O2 using three-dimensional electron diffraction and precession electron diffraction”. Quintelier M, Perkisas T, Poppe R, Batuk M, Hendrickx M, Hadermann J, Symmetry-Basel 13, 1989 (2021). http://doi.org/10.3390/SYM13111989
Abstract: Among lithium battery cathode materials, Li1.2Ni0.13Mn0.54Co0.13O2 (LR-NMC) has a high theoretical capacity, but suffers from voltage and capacity fade during cycling. This is partially ascribed to transition metal cation migration, which involves the local transformation of the honeycomb layered structure to spinel-like nano-domains. Determination of the honeycomb layered/spinel phase ratio from powder X-ray diffraction data is hindered by the nanoscale of the functional material and the domains, diverse types of twinning, stacking faults, and the possible presence of the rock salt phase. Determining the phase ratio from transmission electron microscopy imaging can only be done for thin regions near the surfaces of the crystals, and the intense beam that is needed for imaging induces the same transformation to spinel as cycling does. In this article, it is demonstrated that the low electron dose sufficient for electron diffraction allows the collection of data without inducing a phase transformation. Using calculated electron diffraction patterns, we demonstrate that it is possible to determine the volume ratio of the different phases in the particles using a pair-wise comparison of the intensities of the reflections. Using this method, the volume ratio of spinel structure to honeycomb layered structure is determined for a submicron sized crystal from experimental three-dimensional electron diffraction (3D ED) and precession electron diffraction (PED) data. Both twinning and the possible presence of the rock salt phase are taken into account. After 150 charge-discharge cycles, 4% of the volume in LR-NMC particles was transformed irreversibly from the honeycomb layered structure to the spinel structure. The proposed method would be applicable to other multi-phase materials as well.
Keywords: A1 Journal article; Engineering sciences. Technology; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Impact Factor: 1.457
DOI: 10.3390/SYM13111989
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“A superellipse with deformation and its application in describing the cross-sectional shapes of a square bamboo”. Huang W, Li Y, Niklas KJ, Gielis J, Ding Y, Cao L, Shi P, Symmetry-Basel 12, 2073 (2020). http://doi.org/10.3390/SYM12122073
Abstract: Many cross-sectional shapes of plants have been found to approximate a superellipse rather than an ellipse. Square bamboos, belonging to the genus Chimonobambusa (Poaceae), are a group of plants with round-edged square-like culm cross sections. The initial application of superellipses to model these culm cross sections has focused on Chimonobambusa quadrangularis (Franceschi) Makino. However, there is a need for large scale empirical data to confirm this hypothesis. In this study, approximately 750 cross sections from 30 culms of C. utilis were scanned to obtain cross-sectional boundary coordinates. A superellipse exhibits a centrosymmetry, but in nature the cross sections of culms usually deviate from a standard circle, ellipse, or superellipse because of the influences of the environment and terrain, resulting in different bending and torsion forces during growth. Thus, more natural cross-sectional shapes appear to have the form of a deformed superellipse. The superellipse equation with a deformation parameter (SEDP) was used to fit boundary data. We find that the cross-sectional shapes (including outer and inner rings) of C. utilis can be well described by SEDP. The adjusted root-mean-square error of SEDP is smaller than that of the superellipse equation without a deformation parameter. A major finding is that the cross-sectional shapes can be divided into two types of superellipse curves: hyperellipses and hypoellipses, even for cross sections from the same culm. There are two proportional relationships between ring area and the product of ring length and width for both the outer and inner rings. The proportionality coefficients are significantly different, as a consequence of the two different superellipse types (i.e., hyperellipses and hypoellipses). The difference in the proportionality coefficients between hyperellipses and hypoellipses for outer rings is greater than that for inner rings. This work informs our understanding and quantifying of the longitudinal deformation of plant stems for future studies to assess the influences of the environment on stem development. This work is also informative for understanding the deviation of natural shapes from a strict rotational symmetry.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.7
DOI: 10.3390/SYM12122073
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“Structural phase transformations in alloys: an electron microscopy study”. Van Tendeloo G, Schryvers D, Tanner LE, Broddin D, Ricolleau C, Loiseau A, Symposium on Pahse Transformations , 1 (1991)
Keywords: P3 Proceeding; Electron microscopy for materials research (EMAT)
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“Conductivity and electron density of undoped model compounds of poly(phenylene vinylene)”. Yang Z, Geise HJ, Mehbod M, Debrue G, Visser JW, Sonneveld EJ, Van 't dack L, Gijbels R, Synthetic metals 39, 137 (1990). http://doi.org/10.1016/0379-6779(90)90179-O
Abstract: Fourteen derivatives of trans,trans-1,4-bis[2-phenylethenyl]benzene were synthesized by Wittig reactions as model compounds of poly(paraphenylene vinylene). Structure, configurational homogeneity and absence of ionic impurities were controlled by mass spectrometry, infrared and neutron activation analysis, respectively. Crystallographic unit cell parameters were obtained from X-ray powder patterns and measurements of electrical conductivities were performed on undoped samples. The data of four more compounds containing one or more thiophene rings instead of phenyl rings were added from the 3iterature. If NO2 and Cl groups are excluded from the electron count a good linear correlation is found between the logarithm of the conductivity and the non-σ electron density (View the MathML source). The position of the substituents, on the central or on the terminal ring, also plays a role in as much as it affects the molecular volume of the compound but not the non-σ electron density. The correlation between the logarithm of the conductivity and the absorption coefficient of the longest wavelength of UV absorption identifies the π electrons in the chromophore as the principal charge carriers.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.252
Times cited: 25
DOI: 10.1016/0379-6779(90)90179-O
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“Urine nitrification with a synthetic microbial community”. Christiaens MER, De Paepe J, Ilgrande C, De Vrieze J, Barys J, Teirlinck P, Meerbergen K, Lievens B, Boon N, Clauwaert P, Vlaeminck SE, Systematic and applied microbiology 42, Unsp 126021 (2019). http://doi.org/10.1016/J.SYAPM.2019.126021
Abstract: During long-term extra-terrestrial missions, food is limited and waste is generated. By recycling valuable nutrients from this waste via regenerative life support systems, food can be produced in space. Astronauts' urine can, for instance, be nitrified by micro-organisms into a liquid nitrate fertilizer for plant growth in space. Due to stringent conditions in space, microbial communities need to be be defined (gnotobiotic); therefore, synthetic rather than mixed microbial communities are preferred. For urine nitrification, synthetic communities face challenges, such as from salinity, ureolysis, and organics. In this study, a synthetic microbial community containing an AOB (Nitrosomonas europaea), NOB (Nitrobacter winogradskyi), and three ureolytic heterotrophs (Pseudomonas fluorescens, Acidovorax delafieldii, and Delftia acidovorans) was compiled and evaluated for these challenges. In reactor 1, salt adaptation of the ammonium-fed AOB and NOB co-culture was possible up to 45 mS cm(-1), which resembled undiluted nitrified urine, while maintaining a 44 +/- 10 mg NH4+-N L-1 d(-1) removal rate. In reactor 2, the nitrifiers and ureolytic heterotrophs were fed with urine and achieved a 15 +/- 6 mg NO3--N L-1 d(-1) production rate for 1% and 10% synthetic and fresh real urine, respectively. Batch activity tests with this community using fresh real urine even reached 29 +/- 3 mg N L-1 d(-1). Organics removal in the reactor (69 +/- 15%) should be optimized to generate a nitrate fertilizer for future space applications. (C) 2019 Elsevier GmbH. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.SYAPM.2019.126021
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“Evaluation of a calibration transfer between a bench top and portable Mid-InfraRed spectrometer for cocaine classification and quantification”. Eliaerts J, Meert N, Dardenne P, Van Durme F, Baeten V, Samyn N, De Wael K, Talanta 209, 120481 (2020). http://doi.org/10.1016/J.TALANTA.2019.120481
Abstract: A portable Fourier Transform Mid-InfraRed (FT-MIR) spectrometer using Attenuated Total Reflectance (ATR) sampling is used for daily routine screening of seized powders. Earlier, ATR-FT-MIR combined with Support Vector Machines (SVM) algorithms resulted in a significant improvement of the screening method to a reliable and straightforward classification and quantification tool for both cocaine and levamisole. However, can this tool be transferred to new (hand-held) devices, without loss of the extensive data set? The objective of this study was to perform a calibration transfer between a newly purchased bench top (BT) spectrometer and a portable (P) spectrometer with existing calibration models. Both instruments are from the same brand and have identical characteristics and acquisition parameters (FT instrument, resolution of 4 cm(-1) and wavenumber range 4000 to 500 cm(-1)). The original SVM classification model (n = 515) and SVM quantification model (n = 378) were considered for the transfer trial. Three calibration transfer strategies were assessed: 1) adjustment of slope and bias; 2) correction of spectra from the new instrument BT to P using Piecewise Direct Standardization (PDS) and 3) building a new mixed instrument model with spectra of both instruments. For each approach, additional cocaine powders were measured (n = 682) and the results were compared with GC-MS and GC-FID. The development of a mixed instrument model was the most successful in terms of performance. The future strategy of a mixed model allows applying the models, developed in the laboratory, to portable instruments that are used on-site, and vice versa. The approach offers opportunities to exchange data within a network of forensic laboratories using other FT-MIR spectrometers.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.1
Times cited: 2
DOI: 10.1016/J.TALANTA.2019.120481
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“Macroscopic mid-FTIR mapping and clustering-based automated data-reduction : an advanced diagnostic tool for in situ investigations of artworks”. Sciutto G, Legrand S, Catelli E, Prati S, Malegori C, Oliveri P, Janssens K, Mazzeo R, Talanta 209, 120575 (2020). http://doi.org/10.1016/J.TALANTA.2019.120575
Abstract: The present study describes a multivariate strategy that can be used for automatic on-site processing of reflection mode macro FTIR mapping (MA-rFTIR) data obtained during investigation of artworks. The chemometric strategy is based on the integration of principal component analysis (PCA) with a clustering approach in the space subtended by the three lowest-order principal components and allows to automatically identify the regions of interest (ROIs) of the area scanned and to extract the average FTIR spectra related to each ROI. Thanks to the automatic data management, in-field HSI (hyperspectral imaging)-based analyses may be performed even by staff lacking specific advanced chemometric expertise, as it is sometimes the case for conservation scientists or conservators with a scientific background. MA-rFTIR was only recently introduced in the conservation field and, in this work the technique was employed to characterize the surface of metallic artefacts. The analytical protocol was employed as part of a rapid procedure to evaluate the conservation state and the performance of cleaning methods on bronze objects. Both activities are commonly part of restoration campaigns of bronzes and require an on-site analytical procedure for efficient and effective diagnosis. The performance of the method was first evaluated on aged standard samples (bronzes with a layer of green basic copper hydroxysulphate, treated with different organic coatings) and then scrutinized in situ on areas of the 16th century Neptune fountain statue (Piazza del Nettuno, Bologna, Italy) by Gianbologna.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.1
DOI: 10.1016/J.TALANTA.2019.120575
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“The opportunity of 6-monoacetylmorphine to selectively detect heroin at preanodized screen printed electrodes”. Felipe Montiel N, Parrilla M, Beltrán V, Nuyts G, Van Durme F, De Wael K, Talanta , 122005 (2021). http://doi.org/10.1016/j.talanta.2020.122005
Abstract: The illicit consumption of heroin is an increasing concern in our society. For this reason, rapid analytical methods to seize heroin samples in the field are of paramount importance to hinder drug trafficking, and thus prevent the availability of heroin in the drug market. The present work reports on the enriched electrochemical fingerprint of heroin, allowing its selective detection in street samples, based on the use of electrochemical pretreated screen printed electrodes (p-SPE). The voltammetric identification is built on two oxidation peaks of both heroin and its degradation product 6-monoacetylmorphine (6-MAM), generated in alkaline conditions. Interestingly, an anodic pretreatment of the screen printed electrodes (SPE) shifts the peak potential of paracetamol (the most encountered cutting agent in heroin seizures), allowing the detection of 6-MAM peak, overlapping with the paracetamol signal in the case of untreated SPE. Subsequently, the characterization of the p-SPE with scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, Raman and Fourier transform infrared (FTIR) spectroscopy is provided to demonstrate local changes on the surface of the electrode. From an analytical perspective, p-SPE provide higher sensitivity (0.019 μA μM-1), excellent reproducibility (6-MAM, RSD = 2.85%, and heroin RSD = 0.91%, n = 5) and lower limits of detection (LOD) (5.2 μM) in comparison to untreated SPE. The proposed protocol which integrates a tailor-made script is interrogated against common cutting agents, and finally, validated with the screening of 14 street samples, also analyzed by standard methods. Besides, a comparison with portable spectroscopic techniques on the confiscated samples shows the better performance of the electrochemical strategy. Overall, this sensing approach offers promising results for the rapid on-site profiling of suspicious heroin samples, also in the presence of paracetamol.
Keywords: A1 Journal Article; Antwerp X-ray Analysis, Electrochemistry and Speciation (AXES) ;
Impact Factor: 4.162
DOI: 10.1016/j.talanta.2020.122005
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“The analysis of volatile siloxanes in waste activated sludge”. Dewil R, Appels L, Baeyens J, Van Vaeck L, Buczyńska A, Talanta 74, 14 (2007). http://doi.org/10.1016/J.TALANTA.2007.05.041
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.TALANTA.2007.05.041
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“Aptamer-ligand recognition studied by native ion mobility-mass spectrometry”. Daems E, Dewaele D, Barylyuk K, De Wael K, Sobott F, Talanta 224, 121917 (2021). http://doi.org/10.1016/J.TALANTA.2020.121917
Abstract: The range of applications for aptamers, small oligonucleotide-based receptors binding to their targets with high specificity and affinity, has been steadily expanding. Our understanding of the mechanisms governing aptamer-ligand recognition and binding is however lagging, stymieing the progress in the rational design of new aptamers and optimization of the known ones. Here we demonstrate the capabilities and limitations of native ion mobility-mass spectrometry for the analysis of their higher-order structure and non-covalent interactions. A set of related cocaine-binding aptamers, displaying a range of folding properties and ligand binding affinities, was used as a case study in both positive and negative electrospray ionization modes. Using carefully controlled experimental conditions, we probed their conformational behavior and interactions with the high-affinity ligand quinine as a surrogate for cocaine. The ratios of bound and unbound aptamers in the mass spectra were used to rank them according to their apparent quinine-binding affinity, qualitatively matching the published ranking order. The arrival time differences between the free aptamer and aptamer-quinine complexes were consistent with a small ligand-induced conformational change, and found to inversely correlate with the affinity of binding. This mass spectrometry-based approach provides a fast and convenient way to study the molecular basis of aptamer-ligand recognition.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.162
DOI: 10.1016/J.TALANTA.2020.121917
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“Unlocking the full potential of voltammetric data analysis : a novel peak recognition approach for (bio)analytical applications”. Van Echelpoel R, de Jong M, Daems D, van Espen P, De Wael K, Talanta 233, 122605 (2021). http://doi.org/10.1016/J.TALANTA.2021.122605
Abstract: Bridging the gap between complex signal data output and clear interpretation by non-expert end-users is a major challenge many scientists face when converting their scientific technology into a real-life application. Currently, pattern recognition algorithms are the most frequently encountered signal data interpretation algorithms to close this gap, not in the least because of their straight-forward implementation via convenient software packages. Paradoxically, just because their implementation is so straight-forward, it becomes cumbersome to integrate the expert's domain-specific knowledge. In this work, a novel signal data interpretation approach is presented that uses this domain-specific knowledge as its fundament, thereby fully exploiting the unique expertise of the scientist. The new approach applies data preprocessing in an innovative way that transcends its usual purpose and is easy to translate into a software application. Multiple case studies illustrate the straight-forward application of the novel approach. Ultimately, the approach is highly suited for integration in various (bio)analytical applications that require interpretation of signal data.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.162
DOI: 10.1016/J.TALANTA.2021.122605
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“Fast steel-cleanness characterization by means of laser-assisted plasma spectrometric methods”. Mueller G, Stahnke F, Bleiner D, Talanta : the international journal of pure and applied analytical chemistry
T2 –, 34th Colloquium Spectroscopicum Internationale, SEP 04-09, 2005, Univ Antwerp, Antwerp, BELGIUM (2006). http://doi.org/10.1016/J.TALANTA.2006.05.047
Abstract: Laser-assisted plasma spectrometry is a palette of analytical techniques (L-OES, LA-ICP-MS) capable of fast spatially-resolved elemental analysis in the micrometer range. For fast estimation of the occurrence in steel samples of non-metallic inclusions, which degrade the material's technical properties, simultaneous OES detection and sequential ICP-MS detection were compared. Histograms were obtained for the intensity distribution of the acquired signals (laser pulse statistics). The skewness coefficient of the histograms for Al (indicator of non-metallic inclusions) was found to be clearly dependent on the fraction of non-metallic inclusions in the case of scanning L-OES. For LA-ICP-MS less clear dependence was observed, which was influenced by the acquisition characteristics. In fact, less measurement throughput limited for LA-ICP-MS the counting statistics to an extent that overrides the benefit of higher detection power as compared to L-OES. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.162
Times cited: 12
DOI: 10.1016/J.TALANTA.2006.05.047
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“Colloquium Spectroscopicum Internationale 34, Antwerp, Belgium, 4-9 September 2005: preface”. Janssens K, Bogaerts A, van Grieken R, Talanta : the international journal of pure and applied analytical chemistry 70, 907 (2006). http://doi.org/10.1016/j.talanta.2006.05.044
Keywords: Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.162
DOI: 10.1016/j.talanta.2006.05.044
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“FIB, TEM and LA-ICPMS investigations on melt inclusions in Martian meteorites –, Analytical capabilities and geochemical insights”. Bleiner D, Macri M, Gasser P, Sautter V, Maras A, Talanta : the international journal of pure and applied analytical chemistry (2006). http://doi.org/10.1016/J.TALANTA.2005.08.022
Abstract: In order to obtain full information coverage on melt inclusions in Martian meteorites (subgroup nakhlites) complementary micro-analytical techniques were used, i.e. focused ion beam, transmission electron microscopy and laser ablation. Using focused ion beam several lamellae for transmission electron microscopy were prepared and secondary electron images of cross-sections could be acquired. Laser ablation-inductively coupled plasma mass spectrometry analyses were performed on selected inclusions to obtain mass-oriented bulk composition of inclusions at depth. The differences in composition between melt inclusions in olivine and augite crystals would suggest a xenocrystic origin for olivine. Furthermore, electron diffraction patterns clearly indicated that the SiO2-rich phase in inclusions from augite in meteorites from Northwest Africa site is re-crystallized, whereas it is still vitreous in the inclusions from Nakhla sampling site. Therefore, different post-entrapment evolutions were active for the two nakhlite meteorite sets, the Nakhla and the NWA817 set. Melt inclusions in Nakhla olivine presented alteration veins, which were presumably produced before their landing on Earth. If this is the case, this would indicate a alteration stage already on Mars with all the consequence in terms of climate history. Melt inclusions in Nakhla augite resulted unaffected by any alteration or modification following the entrapment, and therefore represent the best candidate to indicate the pristine magma composition. (c) 2005 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.162
Times cited: 9
DOI: 10.1016/J.TALANTA.2005.08.022
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“An adhesive conducting electrode material based on commercial mesoporous titanium dioxide as a support for Horseradish peroxidase for bioelectrochemical applications”. Rahemi V, Trashin S, Meynen V, De Wael K, Talanta : the international journal of pure and applied analytical chemistry 146, 689 (2016). http://doi.org/10.1016/J.TALANTA.2015.06.041
Abstract: An adhesive conducting electrode material containing of graphite, biocompatible ion exchange polymer nafion® and commercial mesoporous TiO2 impregnated with horseradish peroxidase (HRP) is prepared and characterized by amperometric, UVvis and N2 sorption methods. The factors influencing the performance of the resulting biosensor are studied in detail. The optimal electrode material consists of 45% graphite, 50% impregnated HRPTiO2 and 5% nafion®. The optimum conditions for H2O2 reduction are an applied potential of 0.3 V and 0.1 mM hydroquinone. Sensitivity and limit of detection in the optimum conditions are 1 A M−1 cm−2 and 1 µM correspondingly. The N2 sorption results show that the pore volume of TiO2 decreases sharply upon adsorption of HRP. The preparation process of the proposed enzyme electrode is straightforward and potentially can be used for preparation of carbon paste electrodes for bioelectrochemical detections.
Keywords: A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.162
Times cited: 7
DOI: 10.1016/J.TALANTA.2015.06.041
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“Chemical boundary conditions for the classification of aerosol particles using computer controlled electron probe microanalysis”. Anaf W, Horemans B, Van Grieken R, De Wael K, Talanta : the international journal of pure and applied analytical chemistry 101, 420 (2012). http://doi.org/10.1016/J.TALANTA.2012.09.051
Abstract: A method for the classification of individual aerosol particles using computer controlled electron probe microanalysis is presented. It is based on chemical boundary conditions (CBC) and enables quick and easy processing of a large set of elemental concentration data (mass%), derived from the X-ray spectra of individual particles. The particles are first classified into five major classes (sea salt related, secondary inorganic, minerals, iron-rich and carbonaceous), after which advanced data mining can be performed by examining the elemental composition of particles within each class into more detail (e.g., by ternary diagrams). The CBC method is validated and evaluated by comparing its results with the output obtained with hierarchical cluster analysis (HCA) for well-known standard particles as well as real aerosol particles collected with a cascade impactor. The CBC method gives reliable results and has a major advantage compared to HCA. CBC is based on boundary conditions that are derived from chemical logical thinking and does not require a translation of a mathematical algorithm output as does HCA. Therefore, the CBC method is more objective and enables comparison between samples without intermediate steps.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.162
Times cited: 3
DOI: 10.1016/J.TALANTA.2012.09.051
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“Optimization of the ion chromatographic quantification of airborne fluoride, acetate and formate in the Metropolitan Museum of Art, New York”. Kontozova-Deutsch V, Deutsch F, Bencs L, Krata A, Van Grieken R, De Wael K, Talanta : the international journal of pure and applied analytical chemistry 86, 372 (2011). http://doi.org/10.1016/J.TALANTA.2011.09.030
Abstract: Ion chromatographic (IC) methods have been compared in order to achieve an optimal separation of fluoride, acetate and formate under various elution conditions on two formerly introduced analytical columns (i and ii) and a novel one (iii): (i) an IonPac AS14 (250 mm × 4 mm I.D.), (ii) Allsep A-2 (150 mm × 4.6 mm I.D.), and (iii) an IC SI-50 4E (250 mm (length) × 4 mm (internal diameter – I.D.)). The IC conditions for the separation of the anions concerned were optimized on the IC SI-50 4E column. A near baseline separation of these anions was attained on the IonPac AS14, whereas the peaks of fluoride and acetate could not be resolved on the Allsep A-2. A baseline separation for the three anions was achieved on the IC SI-50 4E column, when applying an eluent mixture of 3.2 mmol/L Na2CO3 and 1.0 mmol/L NaHCO3 with a flow rate of 1.0 mL/min. The highest precision of 1.7, 3.0 and 2.8% and the best limits of detection (LODs) of 0.014, 0.22 and 0.17 mg/L for fluoride, acetate and formate, respectively, were obtained with the IC SI-50 4E column. Hence, this column was applied for the determination of the acetic and formic acid contents of air samples taken by means of passive gaseous sampling at the Metropolitan Museum of Art in New York, USA. Atmospheric concentrations of acetic and formic acid up to 1050 and 450 μg/m3, respectively, were found in non-aerated showcases of the museum. In galleries and outdoors, rather low levels of acetic and formic acid were detected with average concentrations of 50 and 10 μg/m3, respectively. The LOD data of acetate and formate on the IC SI-50 4E column correspond to around 0.5 μg/m3 for both acetic and formic acid in air samples.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.162
Times cited: 19
DOI: 10.1016/J.TALANTA.2011.09.030
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“Polymer platforms for selective detection of cocaine in street samples adulterated with levamisole”. Florea A, Cowen T, Piletsky S, De Wael K, Talanta : the international journal of pure and applied analytical chemistry 186, 362 (2018). http://doi.org/10.1016/J.TALANTA.2018.04.061
Abstract: Accurate drug detection is of utmost importance for fighting against drug abuse. With a high number of cutting agents and adulterants being added to cut or mask drugs in street powders the number of false results is increasing. We demonstrate for the first time the usefulness of employing polymers readily synthesized by electrodeposition to selectively detect cocaine in the presence of the commonly used adulterant levamisole. The polymers were selected by computational modelling to exhibit high binding affinity towards cocaine and deposited directly on the surface of graphene-modified electrodes via electropolymerization. The resulting platforms allowed a distinct electrochemical signal for cocaine, which is otherwise suppressed by levamisole. Square wave voltammetry was used to quantify cocaine alone and in the presence of levamisole. The usefulness of the platforms was demonstrated in the screening of real street samples.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 4.162
Times cited: 9
DOI: 10.1016/J.TALANTA.2018.04.061
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