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See detailComposite modeling to enhance hydraulic structures studies
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Proceedings of SimHydro 2012 (2012)

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow ... [more ▼]

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow problems analyses. Indeed, it enables combining the inherent advantages of both approaches, which are complementary, while being beneficial to the delays as well as the quality of the analysis. The paper presents the way composite modeling is applied for years at the HECE - Laboratory of Engineering Hydraulics (University of Liege) to enhance hydraulic structures studies. Besides numerical model validation for which experimental benchmarks constitute the first reliable data source, simultaneous application of both modeling approaches may be envisaged in three different ways. Composite modeling may be used to increase the scale factor of physical models by reducing the layout of the real structure to be modeled, to provide a better answer to specific problems than a single approach study or to maximize the efficiency of experimental tests by reducing the range of variation of the unknown parameters to be tested. For each of these three issues depicted in the paper, several examples show how the combined use of efficient numerical solvers together with physical scale models enables to increase the overall quality and scope of the analyses while decreasing the delays and possibly the costs. [less ▲]

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See detailComposite modeling to enhance hydraulic structures studies
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Houille Blanche (2012), 6

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow ... [more ▼]

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow problems analyses. Indeed, it enables combining the inherent advantages of both approaches, which are complementary, while being beneficial to the delays as well as the quality of the analysis. The paper presents the way composite modeling is applied for years at the HECE - Laboratory of Engineering Hydraulics (University of Liege) to enhance hydraulic structures studies. Besides numerical model validation for which experimental benchmarks constitute the first reliable data source, simultaneous application of both modeling approaches may be envisaged in three different ways. Composite modeling may be used to increase the scale factor of physical models by reducing the layout of the real structure to be modeled, to provide a better answer to specific problems than a single approach study or to maximize the efficiency of experimental tests by reducing the range of variation of the unknown parameters to be tested. For each of these three issues depicted in the paper, several examples show how the combined use of efficient numerical solvers together with physical scale models enables to increase the overall quality and scope of the analyses while decreasing the delays and possibly the costs. [less ▲]

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See detailComposite smooth estimation of the state price density implied in option prices
Frasso, Gianluca ULg

in Kneib, Thomas; Sobotka, Fabian; Fahrenholz, Jan (Eds.) et al 29th International Workshop on Statistical Modelling, Göttingen, Germany, 2014, Proceedings (2014, July)

We propose a new semi-parametric approach for the estimation of the State Price Density (SPD) implied in option prices. Our procedure is inspired by a Penalized Composite Link Model (PCLM) approach and ... [more ▼]

We propose a new semi-parametric approach for the estimation of the State Price Density (SPD) implied in option prices. Our procedure is inspired by a Penalized Composite Link Model (PCLM) approach and ensures smooth and arbitrage-free estimates. [less ▲]

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See detailComposite steel-concrete joints in braced frames for buildings
Jaspart, Jean-Pierre ULg

in Composite steel-concrete joints in braced frames for buildings (1996)

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See detailComposite steel-concrete joints in frames for buildings: Design provisions
Jaspart, Jean-Pierre ULg

in Composite steel-concrete joints in frames for buildings: Design provisions (1999)

Detailed reference viewed: 33 (3 ULg)
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See detailComposite structures design for strength and stiffness with respect to ply thickness and/or fibers orientation
Bruyneel, Michaël ULg; Duysinx, Pierre ULg; Fleury, Claude ULg

in CHENG, Gen Dong (Ed.) Proceedings of the 4th World Congress of Structural and Multidisciplinary Optimization WCSMO4 (2001, June)

This paper presents an optimization approach that allows the design of composite structures under stiffness and strength criteria, with fibers orientations and plies thickness taken into account in the ... [more ▼]

This paper presents an optimization approach that allows the design of composite structures under stiffness and strength criteria, with fibers orientations and plies thickness taken into account in the same optimization loop. The approach is based on the sequential convex programming. An industrial application is presented. [less ▲]

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See detailComposite structures optimization including non-linear finite element analysis, design and manufacturing considerations
Bruyneel, Michaël ULg; Grihon, Stéphane; Hudson, Leigh

in NAFEMS World Congress (2015)

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See detailComposite structures optimization using sequential convex programming
Bruyneel, Michaël ULg; Fleury, Claude ULg

in Advances in Engineering Software (2002), 33(7-10), 697-711

The design of composite structures is considered here. The approximation concepts approach is used to solve the optimization problem. The convex approximations of the MMA family are briefly described ... [more ▼]

The design of composite structures is considered here. The approximation concepts approach is used to solve the optimization problem. The convex approximations of the MMA family are briefly described. Several modifications of these approximations are presented. They are now based on gradient information at two successive iterations, avoiding the use of the expensive second-order derivatives. A two-point fitting scheme is also described, where the function value at the preceding design point is used to improve the approximation. Numerical examples compare these new purely non-monotonous schemes to the existing ones for the selection of optimal fibers orientations in laminates. It is shown how these two-point based approximations are well adapted to the problem and can improve the optimization task, leading to reasonable computational efforts. A procedure is also derived for considering simultaneously monotonous and non-monotonous structural behaviors. The resulting generalized approximation scheme is well suited for the optimization of composite structures when both plies thickness and fibers orientations are considered as design variables. It is concluded that the newly developed approximation schemes of the MMA family are reliable for composite structures optimization. All the studied approximations are convex and separable: the optimization problem can then be solved using a dual approach. (C) 2002 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailLes composites à matrice métallique/céramique – De nouveaux procédés de fabrication pour de nouvelles applications
Mertens, Anne ULg; Lecomte-Beckers, Jacqueline ULg

Conference (2014, May 20)

A l’heure où la plupart des matériaux composites essentiellement structuraux sont faits d’une matrice à base polymère, les matériaux composites à matrice métallique ou céramique offrent de nouvelles ... [more ▼]

A l’heure où la plupart des matériaux composites essentiellement structuraux sont faits d’une matrice à base polymère, les matériaux composites à matrice métallique ou céramique offrent de nouvelles perspectives en termes de performances et de durabilité. Le présent exposé s’attache plus particulièrement à retracer les possibilités offertes par de nouvelles méthodes de mise en oeuvre telles que la friction-malaxage et les techniques d’impression 3D, aussi bien en termes d’amélioration des propriétés mécaniques des matériaux composites que des fonctionnalités inédites qui peuvent leur être conférées. [less ▲]

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See detailComposition and biological activities of the essential oil of Nigella sativa seeds isolated by accelerated microwave steam distillation with cryogenic grinding
Alkoul, R; Benkaci-Ali, F; Zerrouki, M et al

in American Journal of Essential Oils and Natural Products (2014), 1(3), 23-33

In this study, essential oil of Sahara Nigella sativa L. was extracted using a rapid extraction, the microwave steam distillation (MSD) and the cryogenic grinding (CG). Two procedures have been ... [more ▼]

In this study, essential oil of Sahara Nigella sativa L. was extracted using a rapid extraction, the microwave steam distillation (MSD) and the cryogenic grinding (CG). Two procedures have been investigated, the MSD1 (seeds inside of oven apparatus) and MSD2 (seeds outside of oven apparatus). Forty-six compounds were identified and significant differences in quantities of the major constituents were observed, mainly were thymoquinone (CLG: 331.82-443.55 mg and CG: 272.95- 413.57 mg/100 g of seeds), p-cymene (CLG: 181.71-244.17 mg, CG: 369.80- 374.40 mg/100 g of seeds), dehydro-sabina ketone (CLG: 24.60- 25.83 mg, GC: 44.02-50.69 mg/100g of seeds), carvacrol (CLG: 10.32-10.96 mg, CG: 3.91-12.67 mg/100 g of seeds) and longifolene (CLG: 11.90- 16.43 mg, CG: 12.72-19.58 mg/100 g of seeds).Results showed that essential oils exhibit a good activity in each antioxidant system with a special attention for β-carotene bleaching test (IC50: 21 to 27 μg/ml) and reducing power (EC50: 9 to 14 μg/ml).The N. Sativa essential oils exhibited higher antibacterial and antifungal activities varying according to technique extraction and grinding mode used, with a high effectiveness against Gram-positive bacteria with a diameter of inhibition zones growth ranging from 9.5 to 35 mm and MIC and MBC values ranging from (0.042–0.10 mg/ml) to (0.20–0.75 mg/ml), respectively [less ▲]

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See detailComposition and dynamics of the great Phanerozoic Evolutionary Floras
Cleal, Christopher J.; Cascales - Miñana, Borja ULg

in Proceedings of the XXIX Annual Meeting of the Spanish Society of Palaeontology (abstract book) (2013, October)

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See detailComposition and dynamics of the great Phanerozoic Evolutionary Floras
Cleal, Christopher J.; Cascales - Miñana, Borja ULg

in Lethaia (2014), 47(4), 469-484

Factor analysis of a data set representing the global distribution of vascular plant families through time shows the broad pattern of vegetation history can be explained in terms of five Evolutionary ... [more ▼]

Factor analysis of a data set representing the global distribution of vascular plant families through time shows the broad pattern of vegetation history can be explained in terms of five Evolutionary Floras. The Rhyniophytic (=Eotrachyophytic) Flora represents the very earliest (Silurian and earliest Devonian) vascular plants, notably the Rhyniophytopsida. The Eophytic Flora represents the early (Early-Middle Devonian) mainly homosporous land plants, notably the Zosterophyllopsida, Trimerophytopsida and early Lycopsida. The Palaeophytic Flora represents the Late Devonian and Carboniferous vegetation, which saw the introduction of heterospory among the spore producing plants and of early gymnosperms. The Mesophytic Flora first appeared in the Late Carboniferous and Permian macrofossil record, although there is palynological evidence of these plants having grown earlier in extra-basinal habitats and was dominated by gymnosperms with more modern affinities. The Cenophytic Flora that first appeared during Cretaceous times was overwhelmingly dominated by angiosperms. The end-Devonian, end-Triassic and end-Cretaceous mass-extinction events recognized in the marine fossil record had little impact on the diversity dynamics of these Evolutionary Floras. Rather, the changes between floras mainly reflect key evolutionary innovations such as heterospory, ovules and angiospermy. [less ▲]

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See detailComposition And Nutritive-Value For Rats Of Aspergillus-Niger Solid Fermented Barley
Mathot, Pierre; Debevere, Ch.; Walhain, Philippe et al

in Animal Feed Science & Technology (1992), 39(3-4), 227-237

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See detailComposition and orbits of language operations: finiteness and upper bounds
Charlier, Emilie ULg; Domaratzki, Michael; Harju, Tero et al

in International Journal of Computer Mathematics (2013), 90(6), 1171-1196

We consider a set of eight natural operations on formal languages (Kleene closure, positive closure, complement, prefix, suffix, factor, subword, and reversal), and compositions of them. If x and y are ... [more ▼]

We consider a set of eight natural operations on formal languages (Kleene closure, positive closure, complement, prefix, suffix, factor, subword, and reversal), and compositions of them. If x and y are compositions, we say x is equivalent to y if they have the same effect on all languages L. We prove that the number of equivalence classes of these eight operations is finite. This implies that the orbit of any language L under the elements of the monoid is finite and bounded, independently of L. This generalizes previous results about complement, Kleene closure, and positive closure. We also estimate the number of distinct languages generated by various subsets of these operations. [less ▲]

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See detailComposition And Physicochemical Extracted From Whole Seeds By Acid Properties Of Locust Bean Gum Or Water Dehulling Pre-Treatment
Dakia, Patrick; Blecker, Christophe ULg; Robert, Chiristelle et al

in Food Hydrocolloids (2008), 22(5),

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See detailComposition and preparation of hydrogel nanocomposites with improved mechanical properties and use thereof
Herwats, Stéphane; Detrembleur, Christophe ULg; Alexandre, Michaël et al

Patent (2013)

Composition, preparation method and use of a hydrogel nanocomposite (HNC) material, containing one or more water soluble monomers (A), a water swelling clay mineral (B) with a high solubility in water ... [more ▼]

Composition, preparation method and use of a hydrogel nanocomposite (HNC) material, containing one or more water soluble monomers (A), a water swelling clay mineral (B) with a high solubility in water, and water itself(C), with added components resulting in a high compression modulus of the HNC material. [less ▲]

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See detailComposition and Thickness Dependence of GeSn Growth by Chemical Vapor Deposition
Wang, Wei; Shimura, Yosuke; Nieddu, Thomas ULg et al

Conference (2013, June 04)

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See detailComposition chimique comparée des formations squelettiques chez les lophophoriens et les Endoproctes
Jeuniaux, Charles ULg

in Bulletin de la Société Zoologique de France (1982), 107(2), 233-249

Data concerning the chemical composition of exoskeletal structures in Lophophorates (Phoronida, Bryozoa, Brachiopoda) and in Entoprocta are presented and discussed. The inorganic composition is generally ... [more ▼]

Data concerning the chemical composition of exoskeletal structures in Lophophorates (Phoronida, Bryozoa, Brachiopoda) and in Entoprocta are presented and discussed. The inorganic composition is generally well established, as well as chitin distribution and quantitative importance. Proteins, which are often the most abundant constituants, are poorly known, except un the case of Brachiopod shells. [less ▲]

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