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Peer Reviewed
See detailLifetime Measurements for the 4p2P° and 5p2P° Levels and calculation of Transition Probabilities in Na I
Lowe, R. M.; Biémont, Emile ULg

in Journal of Physics : B Atomic Molecular & Optical Physics (1994), 27

Detailed reference viewed: 4 (1 ULg)
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See detailLifetime measurements in odd-parity Rydberg series of neutral Lead by time-resolved laser spectroscopy
Li, Z. S.; Svanberg, S.; Biémont, Emile ULg et al

in Physical Review. A (1998), 57

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See detailLifetime measurements in Ru II and calculated oscillator strengths in Ru II and Ru III
Palmeri, P.; Quinet, Pascal ULg; Fivet, V. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2009), 42

A new set of theoretical f -values is reported for 178 Ru II transitions of astrophysical interest, involving energy levels below 58 000 cm−1. The theoretical model, including core-polarization effects ... [more ▼]

A new set of theoretical f -values is reported for 178 Ru II transitions of astrophysical interest, involving energy levels below 58 000 cm−1. The theoretical model, including core-polarization effects, has been tested by comparing theoretical lifetimes with new measurements performed by time-resolved laser-induced fluorescence spectroscopy for 23 4d6(5D)5p odd levels of Ru II and by comparing theoretical and experimental Land´e g-factors. The first set of transition probabilities is proposed for 25 strong lines depopulating the 4d55p 5,7P◦ terms of Ru III. The new results will allow quantitative investigations of stellar spectra and allow the astrophysicists to refine the ruthenium abundance in stars. [less ▲]

Detailed reference viewed: 12 (1 ULg)
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See detailLifetime measurements in Yb II with time-resolved laser spectroscopy
Li, Z. S.; Svanberg, S.; Quinet, Pascal ULg et al

in Journal of Physics : B Atomic Molecular & Optical Physics (1999), 32

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See detailLifetime measurements of odd-parity high excitation levels of Sn I by time-resolved laser spectroscopy
Zhang, W; Feng, Y; Xu, J et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2010), 43

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See detailLifetime of a Bouncing Droplet
Terwagne, Denis ULg; Vandewalle, Nicolas ULg; Dorbolo, Stéphane ULg

in Physical Review E (2007), 76(5, Pt 2), 56311

When a droplet is gently laid onto the surface of the same liquid, it stays at rest for a moment before coalescence. The coalescence can be delayed and sometimes inhibited by injecting fresh air under the ... [more ▼]

When a droplet is gently laid onto the surface of the same liquid, it stays at rest for a moment before coalescence. The coalescence can be delayed and sometimes inhibited by injecting fresh air under the droplet. This can happen when the surface of the bath oscillates vertically. In this case the droplet basically bounces on the interface. The lifetime of the droplet has been studied with respect to the amplitude and the frequency of the excitation. The lifetime decreases when the acceleration increases. The thickness of the air film between the droplet and the bath has been investigated using interference fringes obtained when the system is illuminated by low-pressure sodium lamps. Moreover, both the shape evolution and the motion of the droplet center of mass have been recorded in order to evidence the phase offset between the deformation and the trajectory. A short lifetime is correlated to a small air-film thickness and to a large phase offset between the maximum of deformation and the minimum of the vertical position of the center of mass. [less ▲]

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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 ▲]

Detailed reference viewed: 11 (3 ULg)
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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

Detailed reference viewed: 5 (1 ULg)
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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 ▲]

Detailed reference viewed: 8 (0 ULg)
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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

Detailed reference viewed: 4 (1 ULg)
See detailLifetimes of the 3d2D levels in Ca II
Biémont, Emile ULg; Zeippen, C. J.

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

Detailed reference viewed: 9 (4 ULg)
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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 ▲]

Detailed reference viewed: 12 (0 ULg)
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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 ▲]

Detailed reference viewed: 108 (12 ULg)