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See detailThe lifetime of bouncing droplets
Terwagne, Denis ULg; Vandewalle, Nicolas ULg; Dorbolo, Stéphane ULg

Conference (2007, October)

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See detailLifetimes along perturbed Rydberg series in neutral thallium
Biémont, Emile ULg; Palmeri, P.; Quinet, Pascal ULg et al

in Journal of Physics B-Atomic Molecular and Optical Physics (2005), 38(19), 3547-3558

Radiative lifetimes of 15 Tl I levels belonging to the 6s(2)ns(2)S(1/2) (n = 7-14) and 6s(2)nd(2)D(3/2) Rydberg series (n = 6-12) have been measured using a time-resolved laser-induced fluorescence ... [more ▼]

Radiative lifetimes of 15 Tl I levels belonging to the 6s(2)ns(2)S(1/2) (n = 7-14) and 6s(2)nd(2)D(3/2) Rydberg series (n = 6-12) have been measured using a time-resolved laser-induced fluorescence technique. All the measured levels have been excited from the ground state 6s(2)6p(2)P(1/2)(0) (odd parity) with a single-step excitation process. The general perturbation of the ns series by the 6s6p(2) configuration and the corresponding modification of the lifetimes are adequately reproduced by a theoretical model including core-polarization effects and combined with a least-squares fit to the observed energy levels. The general behaviour of the lifetime values for the 6s(2)np odd levels along the Rydberg series is also well reproduced. The use of the multiconfiguration quantum defect theory has allowed us to obtain lifetime values along the 6s(2)ns(2)S(1/2) series up to levels with n = 31. [less ▲]

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See detailLifetimes and oscillator strengths for ultravilolet transitions in neutral sulfur
Biémont, Emile ULg; Garnir, Henri-Pierre ULg; Federman, S. R. et al

in Astrophysical Journal (1998), 502

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See detailLifetimes and transition probabilities in In II
Biémont, Emile ULg; Zeippen, C. J.

in At. Data Nucl. Data Tables (1999), 72

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See detailLifetimes in Fe II and the solar abundance of iron
Hannaford, P.; Lowe, R. M.; Grevesse, Nicolas ULg et al

in Astronomy and Astrophysics (1992), 259

New atomic lifetimes have been determined for eight quartet (z 4D, z 4F) levels and ten sextet (z 6D, z 6F, z 6P) levels in Fe II and the results for seven of these levels have been combined with existing ... [more ▼]

New atomic lifetimes have been determined for eight quartet (z 4D, z 4F) levels and ten sextet (z 6D, z 6F, z 6P) levels in Fe II and the results for seven of these levels have been combined with existing experimental branching fractions to obtain a revised set of log gf-values for 15 solar lines in Fe II. The new log gf data are used together with equivalent widths determined from the Liege solar atlas to derive a value for the iron photospheric abundance: 7.48 +/- 0.04, which is consistent with the currently accepted meteoritic result, 7.51 +/- 0.01. The results are compared with the atomic lifetime data, log gf data and solar analyses used in three other recent solar abundance determinations based on Fe II lines. [less ▲]

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See detailLifetimes of metastable levels in ArII
Schef, P.; Derkatch, A.; Lundin, P. et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2004), 29(2), 195-199

We report on a calculation of five lifetimes of metastable levels in Ar II, obtained with a relativistic Hartree-Fock method in which most of the intravalence correlation is represented within a ... [more ▼]

We report on a calculation of five lifetimes of metastable levels in Ar II, obtained with a relativistic Hartree-Fock method in which most of the intravalence correlation is represented within a configuration interaction scheme while core-valence correlation is described by a core-polarization model potential with a core-penetration corrective term. The quality of the calculation has been assessed through an experimental determination of the radiative lifetime of the metastable 3d(4)F(9/2) level. The experiment was performed with a laser probing technique on a stored ion beam at the CRYRING of Stockholm. [less ▲]

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See detailLifetimes of metastable levels of singly ionized titanium: theory and experiment
Palmeri, P.; Quinet, Pascal ULg; Biémont, Emile ULg et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2008), 41

This paper presents new theoretical lifetimes of metastable levels in singly ionized titanium, Ti II. Along with the lifetimes, transition probabilities for several decay channels from these metastable ... [more ▼]

This paper presents new theoretical lifetimes of metastable levels in singly ionized titanium, Ti II. Along with the lifetimes, transition probabilities for several decay channels from these metastable levels are presented. The calculations are supported by experimental lifetime determinations of the 3d3 b 2D5/2 and 3d2(3P)4s b 2P3/2 levels along with revised values of the previously published lifetimes of the 3d2(3P)4s b 4P5/2 and 3d2(3P)4s b 2P1/2 levels originating partly from a reanalysis utilizing a recently developed method applied on the previously recorded data and partly from new measurements. The presented theoretical investigation of lifetimes of metastable levels in Ti II shows that the HFR calculations are in general compatible with measurements performed using the ion storage ring CRYRING of Stockholm University. The transition probabilities of forbidden lines derived from the new lifetime values will be useful for the diagnostics of low density laboratory or astrophysical plasmas, particularly those encountered in the strontium filament found in the ejecta of η Carinae. [less ▲]

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See detailLifetimes of metastable state in Sr II
Biémont, Emile ULg; Lidberg, J.; Mannervik, S. et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2000), 11

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See detailLifetimes of the 3d2D levels in Ca II
Biémont, Emile ULg; Zeippen, C. J.

in Comments on Atomic and Molecular Physics (1996), 33

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See detailLifetimes, oscillator strengths and Lande factors in doubly ionized europium (Eu III)
Quinet, Pascal ULg; Biémont, Emile ULg

in Monthly Notices of the Royal Astronomical Society (2003), 340(2), 463-467

A set of transition probabilities has been calculated for Eu iii transitions of astrophysical interest particularly for the study of chemically peculiar stars. They were obtained taking configuration ... [more ▼]

A set of transition probabilities has been calculated for Eu iii transitions of astrophysical interest particularly for the study of chemically peculiar stars. They were obtained taking configuration interaction and core-polarization effects into account. The accuracy of the new scale of oscillator strengths, which differs substantially from previous results, has been assessed through comparisons with recent time-resolved laser-induced fluorescence measurements of radiative lifetimes. [less ▲]

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See detailLift-and-project inequalities
Louveaux, Quentin ULg

in Wiley Encylopedia of Operations Research and Management Science (2011)

The lift-and-project technique is a systematic way to generate valid inequalities for a mixed binary program. The technique is interesting both on the theoretical and on the practical point of view. On ... [more ▼]

The lift-and-project technique is a systematic way to generate valid inequalities for a mixed binary program. The technique is interesting both on the theoretical and on the practical point of view. On the theoretical side it allows one to construct the inequality description of the convex hull of all mixed-{0,1} solutions of a binary MIP in n repeated applications of the technique, where n is the number of binary variables. On the practical side, a variant of the method allows one to derive some cutting planes from the simplex tableau rather efficiently. [less ▲]

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See detailLifting of valid inequalities revisited
Louveaux, Quentin ULg

Conference (2003, August)

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See detailLifting, Superadditivity, Mixed Integer Rounding and Single Node Flow Sets Revisited
Louveaux, Quentin ULg; Wolsey, Laurence A.

in Annals of Operations Research (2007), 153(1), 47-77

In this survey we attempt to give a unified presentation of a variety of results on the lifting of valid inequalities, as well as a standard procedure com- bining mixed integer rounding with lifting for ... [more ▼]

In this survey we attempt to give a unified presentation of a variety of results on the lifting of valid inequalities, as well as a standard procedure com- bining mixed integer rounding with lifting for the development of strong valid inequalities for knapsack and single node flow sets. Our hope is that the latter can be used in practice to generate cutting planes for mixed integer programs. The survey contains essentially two parts. In the first we present lifting in a very general way, emphasizing superadditive lifting which allows one to lift simultane- ously different sets of variables. In the second, our procedure for generating strong valid inequalities consists of reduction to a knapsack set with a single continuous variable, construction of a mixed integer rounding inequality, and superaddilifting. It is applied to several generalizations of the 0-1 single node flow set. [less ▲]

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See detailLifting, Superadditivity, Mixed Integer Rounding and Single Node Flow Sets Revisited
Louveaux, Quentin ULg; Wolsey, Laurence A.

in 4OR : Quarterly Journal of the Belgian, French and Italian Operations Research Societies (2003), 1

In this survey we attempt to give a unified presentation of a variety of results on the lifting of valid inequalities, as well as a standard procedure combining mixed integer rounding with lifting for the ... [more ▼]

In this survey we attempt to give a unified presentation of a variety of results on the lifting of valid inequalities, as well as a standard procedure combining mixed integer rounding with lifting for the development of strong valid inequalities for knapsack and single node flow sets. Our hope is that the latter can be used in practice to generate cutting planes for mixed integer programs. The survey contains essentially two parts. In the first we present lifting in a very general way, empha- sizing superadditive lifting which allows one to lift simultaneously different sets of variables. In the second, our procedure for generating strong valid inequalities consists of reduction to a knapsack set with a single continuous variable, construc- tion of a mixed integer rounding inequality, and superadditive lifting. It is applied to several generalizations of the 0-1 single node flow set. [less ▲]

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See detailA ligament influences the diversification of damselfishes (Pomacentridae)
Frederich, Bruno ULg; Olivier, Damien ULg; Litsios, Glenn et al

Conference (2013, June)

The Pomacentridae (damselfishes) is one of the most successful families of reef-associated fishes (386 species). In 1981, Stiassny described a synapomorphic trait of the Pomacentridae: the cerato ... [more ▼]

The Pomacentridae (damselfishes) is one of the most successful families of reef-associated fishes (386 species). In 1981, Stiassny described a synapomorphic trait of the Pomacentridae: the cerato-mandibular ligament (CML) joining the hyoid bar (ceratohyal) to the internal part of the mandible (coronoid process of the articulo-angular). Here, we highlight that this ligament is lacking in at least 18 damselfish species from different subclades (i.e. Chrominae, Abudefdufinae and Pomacentrinae) and we explore the impact of its disappearance on lineage, morphological and ecological diversification through their evolutionary history. Using a time-calibrated phylogeny including 208 species, we found no support for different rates of lineage diversification between species that lack the CML and the others. Yet, the CML clearly governs a part of the morphological diversity in damselfishes. Indeed, the body and mandible shapes differ significantly between species without CML and the others. Evolutionary modeling of some phenotypic traits (i.e. body and mandible shape) mainly supports models with two rates of morphological diversification across the time-tree with the species without CML having a higher rate of morphological diversification than the others. Mapping the diet of all studied species illustrates that damselfishes lacking CML are highly zooplanktivorous species. Their shapes suggest they feed on planktonic copepods with a higher contribution of ram-feeding (i.e. predator movement towards prey) in comparison with the other planktivorous damselfishes. Finally, the CML could have promoted easy shifts among the three main trophic guilds in damselfishes (i.e. grazers, zooplanktivorous and omnivorous) during evolution but the disappearance of the CML allowed a functional specialization linked to prey-capture strategies. These results support the primary role of the CML in the evolution and diversification of pomacentrids. [less ▲]

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See detailLigamentoplasties du genou : Intérêt d'un renforcement musculaire préopératoire
Croisier, Jean-Louis ULg; Delcour, Jean-Pierre; Crielaard, Jean-Michel ULg

in Actes du 8ème Congrès National de la Société française de Médecine de Rééducation et de Réadaptation (1993, September)

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See detailLigamentoplasties du genou: l'état musculaire préopératoire conditionne t il le degré d'amyotrophie postopératoire?
Croisier, Jean-Louis ULg; Delcour, J. P.; Crielaard, Jean-Michel ULg

in Annales de Réadaptation et de Médecine Physique (1994), 37

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See detailLigand and Solvation Effects on the Electronic Properties of Au-55 Clusters: A Density Functional Theory Study
Periyasamy, Ganga ULg; Remacle, Françoise ULg

in Nano Letters (2009), 9(8), 3007-3011

The electronic properties of the neutral, positively and negatively charged bare Au-55, passivated Au-55(PH3)(12), Au-55(PH3)(12)Cl-6, and solvated Au-55(PH3)(12)Cl-6 54 H2O clusters are studied using ... [more ▼]

The electronic properties of the neutral, positively and negatively charged bare Au-55, passivated Au-55(PH3)(12), Au-55(PH3)(12)Cl-6, and solvated Au-55(PH3)(12)Cl-6 54 H2O clusters are studied using density functional theory. The presence of Cl atoms in the ligand shell favors a nonmetallic behavior while a more metallic behavior is induced by explicit solvation of Au-55(PH3)(12)Cl-6 with water molecules. The trends observed in the electronic properties upon ligation and solvation are in agreement with experimental studies, [less ▲]

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See detailLigand and solvation effects on the structural and electronic properties of small gold clusters
Dufour, F.; Fresch, Barbara ULg; Durupthy, O. et al

in Journal of Physical Chemistry C: Nanomaterials, Interfaces, and Hard Matter (2014), 118(8), 4362

Detailed reference viewed: 8 (1 ULg)