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See detailFire Resistance of Reinforced Concrete Columns Subjected to Standard Fire – Comparison of an Advanced and a Simplified Method
Achenbach, Marcus; Gernay, Thomas ULg; Morgenthal, Guido

in Garlock, Maria; Kodur, Venkatesh (Eds.) Structures in Fire (Proceedings of the Ninth International Conference) (2016, June 08)

For designing concrete columns subjected to a standard fire exposure, the Eurocode permits the use of simplified or advanced calculation methods. For the designer, the question of the respective ... [more ▼]

For designing concrete columns subjected to a standard fire exposure, the Eurocode permits the use of simplified or advanced calculation methods. For the designer, the question of the respective advantages of these two types of methods arises. Which situations demand the use of an advanced method? When does a simple method provide sufficient accuracy? In this paper, laboratory tests are recalculated using Finite Element Modeling (FEM) as an advanced and Extended Zone Model (EZM) as a simple method in order to investigate these questions. The recalculations indicate that the simple EZM is of sufficient accuracy for symmetric heated columns without restraints. In contrast, the mechanical behavior of columns heated on three sides demands an advanced method such as FEM to be properly described. [less ▲]

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See detailApproche psychocriminologique et légale du processus de radicalisation
Garcet, Serge ULg

Conference (2016, June 08)

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See detailPrediction of intra- and inter-laminar failure of laminates using non-local damage-enhanced mean-field homogenization simulations
Wu, Ling ULg; Sket, Federico; Adam, Laurent et al

Conference (2016, June 08)

The failure of carbon fiber reinforced composites with a quasi-isotropic sequence ([90/45/-45/90/0]S) and open-hole geometry is studied using a multiscale method [1]. On the one hand, the intra-laminar ... [more ▼]

The failure of carbon fiber reinforced composites with a quasi-isotropic sequence ([90/45/-45/90/0]S) and open-hole geometry is studied using a multiscale method [1]. On the one hand, the intra-laminar failure is captured using a damage-enhanced mean-field homogenization scheme. To this end, each ply is modeled as a homogenized material whose anisotropic damage behavior is captured from the homogenization method [2]. In order to avoid the problem of loss of solution uniqueness the mean-field homogenization process is formulated in the context of the non-local continuum damage theory [3]. On the other hand, an hybrid discontinuous Galerkin/extrinsic cohesive law method is used to model the delamination process at the ply interfaces. This hybrid method avoids the need to propagate topological changes in the mesh with the propagation of the delamination while it preserves the consistency and stability in the un-cracked interfaces. As a result, the multiscale framework allows predicting damage propagation directions in each ply along the fiber directions accordingly to the experimental results as it is demonstrated by considering an openhole [90/45/-45/90/0]S-laminate studied both numerically and experimentally. [1] L. Wu, et al., Composite Struct., 126, 246–264, 2015. [2] L. Wu, L. Noels, L. Adam, I. Doghri, Int. J. of Solids and Struct., 50, 3843-3860, 2013. [3] R. Peerlings, et al., Int. J. for Numer. Meth. in Eng., 39, 3391-3403, 1996 [less ▲]

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See detailRevers lifté et coup droit "à plat" : le (néo)libéralisme en débat
Delvenne, Pierre ULg; Rossignol, Nicolas ULg

Article for general public (2016)

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See detailCatalytic reforming of biomass gasification tars with bi- or tri-doped catalysts optimized with organosilane precursors
Claude, Vincent ULg; Courson, Claire; Heinrichs, Benoît ULg et al

Conference (2016, June 08)

The thermochemical method called “biomass gasification” is generating emphatic interest for the production of bio-Syngas (CO + H2) since this process presents the advantage of being renewable without ... [more ▼]

The thermochemical method called “biomass gasification” is generating emphatic interest for the production of bio-Syngas (CO + H2) since this process presents the advantage of being renewable without emitting CO2. However, in practical applications, there are still some technical problems due to high tars concentration in the outlet gas which can condensate and clog the pipes. Many studies have highlighted the fact that the tar elimination via catalytic reforming seem to be the more practical and economical solution. The required properties of the catalysts are determined by its location: inside the reactor (primary catalyst) or outside of the reactor (secondary catalyst). Primary catalysts are generally robust, non-toxic, cheap and they are almost uniquely destined to fluidized bed reactors. Secondary catalysts can be used at the exit of both fluidized and fixed bed reactors. They are characterized by a tailored mesoporous shape, a controlled active site dispersion and an adapted elemental composition [1]. In this work , we decided to focus on designing materials for secondary catalytic applications, i.e. working at relatively low temperature (~650°C) with no mechanical stress. The supports were made of γ-Al2O3 synthesized via an easy Sol-Gel method. During their synthesis, these supports were doped with 10%wt of nickel and various combinations of metallic dopants (Co, Cu, Fe, Mn, Mo) in the aim of enhancing their catalytic activities and lifetime. [less ▲]

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See detailAg/SiO2 and Cu/SiO2 cogelled xerogel catalysts for benzene combustion and 2-butanol deshydrogenation
Mahy, Julien ULg; Claude, Vincent ULg; Tasseroul, Ludivine ULg et al

Poster (2016, June 08)

Tars are recognized as major impurities when biomass is gazified into Syngas (mixture CO + H2) or when the methane reforming was produced from sustainaible reagents [1]. Therefore, fundamental knowledge ... [more ▼]

Tars are recognized as major impurities when biomass is gazified into Syngas (mixture CO + H2) or when the methane reforming was produced from sustainaible reagents [1]. Therefore, fundamental knowledge of catalytic oxidation and deshydrogenation mechanisms can be valuable to develop effective methods to control syngas or methane pollution. A very important concern about cogelled catalysts is the accessibility of the active centers. Because the silver and copper is located inside silica particles, there is a risk that it may not be accessible. In the case of benzene oxidation, it was observed that the specific activity (mol s-1 g-1Ag) of Ag/SiO2 and Cu/SiO2 catalysts increases when the silver or copper loading decreases (Fig. 1). In fact, visual observations by TEM showed that in samples Ag0.25, Ag0.45, Ag1.05 and Cu1.00, there are not silver or copper particles located on silica particles external surface and then the metal dispersion values are greater in these samples. So, it is the proof that Ag and Cu particles located inside the silica particles are accessible for benzene in this catalytic system. In the case of 2-butanol dehydrogenation, the specific activity of Cu/SiO2 catalysts increases when the copper loading increases or when the metal dispersion values decreases (Fig. 2). However, in Cu1.00 sample, copper particles inside silica particles only are observed by TEM. It seems that these metallic particles are accessible for 2-butanol in this catalytic system. [less ▲]

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See detailUne charte en six principes pour guider la mise en œuvre des programmes visant le développement de compétences dans l’enseignement supérieur
Poumay, Marianne ULg; Scheffers, Patricia ULg; Georges, François ULg

Conference (2016, June 08)

Dans l’enseignement supérieur, les programmes se structurent de plus en plus autour de référentiels de compétences, que ces derniers constituent des prescrits légaux ou des choix institutionnels. Mais la ... [more ▼]

Dans l’enseignement supérieur, les programmes se structurent de plus en plus autour de référentiels de compétences, que ces derniers constituent des prescrits légaux ou des choix institutionnels. Mais la cohérence entre le référentiel et le programme est parfois mince. Il arrive en effet que les contraintes de terrain prennent le pas sur les intentions de changement, rendant impossible une réelle « approche visant le développement de compétences » (APC). Force est aussi de constater combien il est complexe de dériver un programme cohérent au départ d’un référentiel de compétences. Pour aider les équipes enseignantes, lors de la refonte d’un programme, à garder le cap sur la notion de compétence telle que définie par Tardif (2006), le LabSET a élaboré une charte en six principes. Cette charte a été utilisée par une dizaine d’équipes libanaises et égyptiennes dans le projet ADIP, lors de la construction de quatre Masters. Les six principes y ont été assortis de recommandations qui président à leur mise en œuvre concrète et serviront de points de repères lors de l’évaluation des programmes. Notre communication partira de ces six principes et de leurs fondements théoriques. Elle explicitera ensuite leur adaptation aux programmes de banque-finance de deux universités libanaises, à travers leur traduction en recommandations concrètes. Elle les illustrera enfin par le cas des architectes de l’ULg, soulignant notamment parmi ces principes ceux qui semblent les plus complexes à mettre en œuvre. [less ▲]

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See detailEnthalpy-Entropy Compensation in the Binding of Modulators at Ionotropic Glutamate Receptor GluA2
Krintel, Christian; Francotte, Pierre ULg; Pickering, Darryl S. et al

in Biophysical Journal (2016), 110

The 1,2,4-benzothiadiazine 1,1-dioxide type of positive allosteric modulators of the ionotropic glutamate receptor A2 (GluA2) are promising lead compounds for the treatment of cognitive disorders, e.g ... [more ▼]

The 1,2,4-benzothiadiazine 1,1-dioxide type of positive allosteric modulators of the ionotropic glutamate receptor A2 (GluA2) are promising lead compounds for the treatment of cognitive disorders, e.g., Alzheimer’s disease. The modulators bind in a cleft formed by the interface of two neighboring ligand binding domains and act by stabilizing the agonist-bound open- channel conformation. The driving forces behind the binding of these modulators can be significantly altered with only minor substitutions to the parent molecules. In this study, we show that changing the 7-fluorine substituent of modulators BPAM97 (2) and BPAM344 (3) into a hydroxyl group (BPAM557 (4) and BPAM521 (5), respectively), leads to a more favorable binding enthalpy (DH, kcal/mol) from 4.9 (2) and 7.5 (3) to 6.2 (4) and 14.5 (5), but also a less favorable binding entropy ( TDS, kcal/mol) from 2.3 (2) and 1.3 (3) to 0.5 (4) and 4.8 (5). Thus, the dissociation constants (Kd, mM) of 4 (11.2) and 5 (0.16) are similar to those of 2 (5.6) and 3 (0.35). Functionally, 4 and 5 potentiated responses of 10 mM L-glutamate at homomeric rat GluA2(Q)i receptors with EC50 values of 67.3 and 2.45 mM, respectively. The binding mode of 5 was examined with x-ray crystallography, showing that the only change compared to that of earlier compounds was the orientation of Ser-497 pointing toward the hydroxyl group of 5. The favorable enthalpy can be explained by the formation of a hydrogen bond from the side-chain hydroxyl group of Ser-497 to the hydroxyl group of 5, whereas the unfavorable entropy might be due to desolva- tion effects combined with a conformational restriction of Ser-497 and 5. In summary, this study shows a remarkable example of enthalpy-entropy compensation in drug development accompanied with a likely explanation of the underlying structural mechanism. [less ▲]

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See detailIntegrated and systemic management of storm damage by the forest-based sector and public authorities
Riguelle, Simon ULg; Hebert, Jacques ULg; Jourez, Benoît ULg

in Annals of Forest Science : a Multidisciplinary and International Journal (2016)

The paper’s goals are to identify key challenges in the currentwindthrow management framework and present a blueprint for howto progress in the settlement of regional strategies.SWOT analyses are used to ... [more ▼]

The paper’s goals are to identify key challenges in the currentwindthrow management framework and present a blueprint for howto progress in the settlement of regional strategies.SWOT analyses are used to highlight relevant issues and opportunities in classical approaches from both the forest-based sector and public authorities’ perspectives. Despite the large body of knowledge that allows decision-makers to react promptly after huge storms, strategic responses still suffer from too individual and fragmented decisions and a lack of holistic economic assessments. To tackle these issues, the paper suggests using systemic and integrated risk management approaches. It also presents the ways to enhance the forest-based sector’s resistance and resilience towards economic shock and supports decision-making with the help of systemic analysis. This shift of paradigm is one of the key requirements in optimizing the way of dealing with storm damage, but public authorities should concur with it more actively by improving decisional and administrative frameworks. Contribution of the co-authors Co-authors are PhD thesis’ supervisors and have thoroughly reviewed the paper. [less ▲]

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See detailMultifractal analysis of the divergence of wavelet series
Esser, Céline ULg

Conference (2016, June 07)

In this talk, we study pointwise divergence properties of wavelet expansions of functions in a given Besov space. We obtain deterministic upper bounds for the Hausdorff dimensions of the sets of points ... [more ▼]

In this talk, we study pointwise divergence properties of wavelet expansions of functions in a given Besov space. We obtain deterministic upper bounds for the Hausdorff dimensions of the sets of points where a given rate of divergence is observed, and we show that these bounds are generically (in the sense of Baire's categories) optimal. This gives a complement to the works done by F. Bayart and Y. Heurteaux in the case of Fourier series and by J.M. Aubry. [less ▲]

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See detailBoltzmann Transport Calculations in Systems with Electron-phonon Coupling
Pike, Nicholas ULg

Scientific conference (2016, June 07)

Recent experimental and theoretical calculations point to a complex interplay between the electron and phonon baths in a wide variety of materials [1,2]. We propose a method of coupling the Boltzmann ... [more ▼]

Recent experimental and theoretical calculations point to a complex interplay between the electron and phonon baths in a wide variety of materials [1,2]. We propose a method of coupling the Boltzmann equations for the electron and phonon baths within the relaxation time approximation to describe the changes in the electron and phonon distributions and thus calculate the thermoelectric transport coefficients. Our model for the coupled system will include tight-binding and ${\bf k \cdot p}$ Hamiltonians for both the electron and phonon energies and analytic calculations for the electron and phonon relaxation mechanisms. From these calculations we hope to better understand the role and interplay of electron-phonon and phonon-phonon interactions on the thermoelectric transport coefficients. [1] - Phys. Rev. Lett. ${\bf 114}$, 115901 (2015). [2] - PNAS ${\bf 112}$, 14777-14782 (2015). [less ▲]

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See detailUniversal amorphous-amorphous transition in GexSe100−x glasses under pressure
Yildirim, Can ULg; Micoulaut, Matthieu; Boolchand, Punit et al

in Scientific Reports (2016), 6

Pressure induced structural modifications in vitreous GexSe100−x (where 10 ≤ x ≤ 25) are investigated using X-ray absorption spectroscopy (XAS) along with supplementary X-ray diffraction (XRD) experiments ... [more ▼]

Pressure induced structural modifications in vitreous GexSe100−x (where 10 ≤ x ≤ 25) are investigated using X-ray absorption spectroscopy (XAS) along with supplementary X-ray diffraction (XRD) experiments and ab initio molecular dynamics (AIMD) simulations. Universal changes in distances and angle distributions are observed when scaled to reduced densities. All compositions are observed to remain amorphous under pressure values up to 42 GPa. The Ge-Se interatomic distances extracted from XAS data show a two-step response to the applied pressure; a gradual decrease followed by an increase at around 15–20 GPa, depending on the composition. This increase is attributed to the metallization event that can be traced with the red shift in Ge K edge energy which is also identified by the principal peak position of the structure factor. The densification mechanisms are studied in details by means of AIMD simulations and compared to the experimental results. The evolution of bond angle distributions, interatomic distances and coordination numbers are examined and lead to similar pressure-induced structural changes for any composition. [less ▲]

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See detailAménorhhée primaire : le point de vue endocrinien
VALDES SOCIN, Hernan Gonzalo ULg

Scientific conference (2016, June 07)

Aménorhhée primaire : le point de vue endocrinien Dr Hernan Valdés-Socin Chef de Clinique. Service d’Endocrinologie. CHU de Liège Résumé L’alternance de la phase folliculaire et lutéale ovarienne ... [more ▼]

Aménorhhée primaire : le point de vue endocrinien Dr Hernan Valdés-Socin Chef de Clinique. Service d’Endocrinologie. CHU de Liège Résumé L’alternance de la phase folliculaire et lutéale ovarienne, s’accompagne d’une variation de la sécrétion oestroprogestative déterminant le cycle menstruel de l’utérus. Les différentes perturbations pouvant toucher les circuits hypothalamiques (neurones à kisspeptines, neurones a GnRH), le fonctionnement hypophysaire et son contrôle des différentes glandes endocrines, les anomalies acquises et génétiques des ovaires (syndrome de Turner, insuffisance ovarienne primaire,etc) et de l’utérus (syndrome d’Asherman, Syndrome de Rokytanski, etc) peuvent déterminer selon les cas une aménorrhée primaire ou secondaire. L’aménorrhée primaire est définie par l’absence de ménarche chez une fille arrivée à l’âge de 16 ans alors que l’aménorrhée secondaire est l’absence de menstruation depuis plus de 3 mois, chez une patiente antérieurement bien réglée. Nous discutons et résumons ici les différentes étiologies d’aménorrhée primaire et secondaire, ainsi que leur prise en charge. La disponibilité récente au CHU de Liège d’un panel de 16 gènes responsables d’hypogonadisme hypogonadotrope nous a permis d’approfondir la recherche sur les causes du syndrome de Kallmann et de l’hypogonadisme hypogonadotrope normosmique. Références H. Valdes-Socin , F.G. Debray, A.S. Parent, M.C. Lebrethon, J.P. Bourguignon, V. Bours A. Beckers. Comment je diagnostique un hypogonadisme hypogonadotrope congénital isolé? Rev Med Liège 2010 Nov;65(11):634-41 Valdes-Socin H, Rubio Almanza M, Tomé Fernández-Ladreda M, Debray FG, Bours V, Beckers A. Reproduction, Smell and Neurodevelopmental disorders: Genetic defects in different hypogonadotropic hypogonadal syndromes. Frontiers in Endocrinology 2014 (5) 109 1-8. Valdes-Socin H, Beckers A. El síndrome de Pasqualini. Medicina (B Aires). 2015;75(1):53-8. B. González Aguilera, P. Syrios, R. Gadisseur, F. Luyckx, E. Cavalier, A. Beckers, H. Valdes-Socin. Persistent low levels of serum hCG due to heterophilic mouse antibodies: an unrecognized pitfall in the diagnosis of trophoblastic disease. Gynecology Endocrinology 2015 Jun;32(6):439-41. H. Valdes-Socin, Fg. Debray, C. Libioulle, A. Pintiaux, As. Parent, V. Corman, K. Gellner, V. Geenen, L. Vroonen, V. Dideberg, V. Bours, A. Beckers. Caractérisation clinique, neuroendocrinienne, génétique et résultats thérapeutiques dans le syndrome de Kallmann et de l’hypogonadisme normosmique idiopathique: expérience liégeoise. Annales d'Endocrinologie - 32ème congrès de la société Française d'Endocrinologie 2016. Bordeaux. France. H. Valdes-Socin (Dr), A. Verloesb , Fg. Debrayc , C. Libioullec , A. Pintiauxd , P. Maquet, A. Beckers) Le Syndrome de De Morsier : une cause congénitale méconnue d’hypopituitarisme. Annales d'Endocrinologie - 32ème congrès de la société Française d'Endocrinologie 2016. Bordeaux. France [less ▲]

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See detailCohesive band model: a triaxiality-dependent cohesive model for damage to crack transition in a non-local implicit discontinuous Galerkin framework
Leclerc, Julien ULg; Wu, Ling ULg; Noels, Ludovic ULg et al

Conference (2016, June 07)

Numerical modelling of the complete ductile failure process is still a challenge. On the one hand, continuous approaches, described by damage models, succeed in the initial diffuse damage stage but are ... [more ▼]

Numerical modelling of the complete ductile failure process is still a challenge. On the one hand, continuous approaches, described by damage models, succeed in the initial diffuse damage stage but are still unable to represent physical discontinuities. On the other hand, discontinuous approaches, such as the cohesive zone models, are able to represent the crack propagation behaviour. They are suited for local damaging processes as crack initiation and propagation, and so, fail in diffuse damage prediction of ductile materials. Moreover, they do not usually capture triaxiality effects, mandatory for accurate ductile failure simulations. To describe the ductile failure process, the numerical scheme proposed here combines both approaches [1] in order to beneficiate from their respective advantages: a non-local damage model combined with an extrinsic cohesive law in a discontinuous Galerkin finite element framework. An application example of this scheme is shown on the attached figure. The initial diffuse damage stage is modelled by an implicit nonlocal damage model as suggested by [2]. Upon damage to crack transition, a cohesive band [3] is used to introduce in-plane stretch effects inside the cohesive law or in other words, a triaxiality-dependent behaviour. Indeed, these in-plane strains play an important role during the ductile failure process and have to be considered. Concretely, when crack appears in the last failure stage, all the damaging process is assumed to occur inside a thin band ahead of the crack surface. Thanks to the small but finite numerical band thickness, the strains inside this band can be obtained from the in-plane strains and from the cohesive jump. Then, the stress-state inside the band and the cohesive traction forces on the crack lips are deduced from the underlying continuum damage model. The band thickness is not a new material parameter but is computed to ensure the energetic consistency during the transition. [1] Wu L, Becker G, Noels L. Elastic damage to crack transition in a coupled non-local implicit discontinuous Galerkin/extrinsic cohesive law framework. Comput. Methods Appl. Mech. Eng. 279 (2014): 379–409 [2] Peerlings R., de Borst R., Brekelmans W., Ayyapureddi S. Gradient-enhanced damage for quasi-brittle materials, Int. J. for Num. Methods in Eng. 39 (1996): 3391-3403 [3] Remmers J. J. C., de Borst R., Verhoosel C. V., Needleman A. The cohesive band model: a cohesive surface formulation with stress triaxiality. Int. J. Fract. 181 (2013): 177–188 [less ▲]

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See detailDe l'avatar au personnage : regards croisés entre game studies et études littéraires
Dozo, Björn-Olav ULg; Delbouille, Julie ULg

Conference (2016, June 07)

Si les game studies se sont développées en prenant appui, dans un premier temps, sur les études littéraires et en particulier sur la narratologie (Ryan 2004, Atkins et Krzywinska 2007) pour interroger la ... [more ▼]

Si les game studies se sont développées en prenant appui, dans un premier temps, sur les études littéraires et en particulier sur la narratologie (Ryan 2004, Atkins et Krzywinska 2007) pour interroger la notion de récit appliquée au jeu vidéo, elles ont ensuite fait appel à d’autres disciplines (psychologie et sociologie en particulier) pour construire leur approche de certaines notions, dont celle d’avatar qui nous paraît utile dans le cadre de recherches sur le personnage en littérature. Confrontées à des objets irréductibles à leur textualité (l’étude de la composante « play » du jeu a pris le pas sur celle du « game », surtout en francophonie – voir à ce sujet Triclot, 2011), les game studies se sont dotées d’outils et de théories propres, réélaborant pragmatiquement certaines notions à partir de théories antérieures (les « univers fictionnels », voir Barnabé, 2014) ou forgeant des concepts spécifiques (l’« impératif d’action », voir Genvo, 2005). Dans cette communication, nous souhaitons mobiliser une série de réflexions récentes sur la notion d’avatar vidéoludique pour les étendre à l’étude des personnages au sein de la littérature contemporaine. [less ▲]

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See detailSet theory and foundational mereology as logical tools for descriptive psychology
Leclercq, Bruno ULg

Conference (2016, June 07)

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See detailL’abus de droit et le manque de réelle substance économique : Belgique
Bourgeois, Marc ULg

Conference given outside the academic context (2016)

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See detailPolitique internationale de la culture: patrimoine culturel et industries culturelles
Vlassis, Antonios ULg

Scientific conference (2016, June 06)

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