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See detailAn Ion Retarding Potential Difference Method applied to Dissociative Photoionization Mass Spectrometry.
Locht, Robert ULg; Rühl, E.; Hagenow, G. et al

in Dalgarno, A.; Freund, R. S.; Lubell, M. S. (Eds.) et al 16th International Conference on the Physics of Electronic and Atomic Collisions: Abstract of Contributed Papers. (1989)

Dissociative photoionization of O2 has been investigated by using the ion retarding potential for the translational energy analysis of the O+ fragment. Synchrotron radiation is used as a light source ... [more ▼]

Dissociative photoionization of O2 has been investigated by using the ion retarding potential for the translational energy analysis of the O+ fragment. Synchrotron radiation is used as a light source. Ionization efficiency curves have been recorded at several retarding potential settings. [less ▲]

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See detailIon Translational Energy Distributions from Inner-shell Dissociative ionization of N2O, NH3 and SF6.
Locht, Robert ULg; Leyh, Bernard ULg; Jochims, H. W. et al

Book published by Berliner Elektronen Speicherring für Synchrotron Strahlung m.b.H (1992)

The IRPD method is applied to the dissociative ionization in the inner-shell ionization region for NO+, N2+, O+, N+ and N++/N2O. Particular attention has been focussed on the production and ion kientic ... [more ▼]

The IRPD method is applied to the dissociative ionization in the inner-shell ionization region for NO+, N2+, O+, N+ and N++/N2O. Particular attention has been focussed on the production and ion kientic energy distribution of H+/NH3. [less ▲]

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See detailIon Traps and Lifetime Calculations in Yb II
Biémont, Emile ULg; Dutrieux, J.-F.; Martin, I. et al

Conference (1998, August)

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See detailIon- and dust-acoustic solitons in dusty plasmas: Existence conditions for positive and negative potential solutions
Verheest, F.; Cattaert, Tom ULg; Hellberg, M. A.

in Physics of Plasmas (2005), 12(8), 8

The usual description of dust-modified ion-acoustic and dust-acoustic solitons in plasmas containing negative dust is in terms of Boltzmann distributions for the hotter species. In the dust-modified ion ... [more ▼]

The usual description of dust-modified ion-acoustic and dust-acoustic solitons in plasmas containing negative dust is in terms of Boltzmann distributions for the hotter species. In the dust-modified ion-acoustic regime, besides positive potential solitons, negative structures can also be generated, for electrons with a polytropic index gamma(e)not equal 1, as well as for Boltzmann electrons, subject to conditions that are not too stringent. These general conditions were previously either ignored or given for weakly nonlinear solutions only. In the dust-acoustic domain in plasmas with negatively charged dust, however, only negative potential solitons can occur, even when the lighter species have non-Boltzmann distributions. For Boltzmann electrons only an infinite dust compression limits the soliton amplitudes and corresponding Mach numbers, whereas for gamma(e)not equal 1, the electron density, too, can be a limiting factor for the existence domain of such solitons. (c) 2005 American Institute of Physics. [less ▲]

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See detailIon-beam analysis for cultural heritage on the AGLAE facility: impact of PIXE/RBS combination
Salomon, Joseph; Dran, Jean-Claude; Guillou, T. et al

in Applied Physics A : Materials Science & Processing (2008), 92(1), 43-50

The combination of particle-induced X-ray emission (PIXE) and Rutherford backscattering (RBS) is particularly fruitful for the study of cultural heritage objects. Several set-ups have been developed at ... [more ▼]

The combination of particle-induced X-ray emission (PIXE) and Rutherford backscattering (RBS) is particularly fruitful for the study of cultural heritage objects. Several set-ups have been developed at the AGLAE facility of the Louvre Laboratory to implement these techniques with an external beam. Successively have been tested the simultaneous use of PIXE and RBS with a single beam of protons, the sequential application of PIXE with protons and RBS with 4He2+ ions and finally the simultaneous implementation of PIXE and RBS with high-energy 4He2+ ions. Several examples illustrate the benefits of these combinations of techniques. [less ▲]

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See detailIon-exchange properties of polypyrrole doped by omega-carboxylated polyethyleneoxide
Jérôme, Christine ULg; Martinot, Lucien; Jérôme, Robert ULg

in Synthetic Metals (1999), 105(1), 65-71

α-Methoxy #969;-Na carboxylate polyethylenoxide (f-PEO) has been synthesized and used as counter-ion for the synthesis of polypyrrole (PPy) films. The effect of f-PEO concentration on the kinetics of ... [more ▼]

α-Methoxy #969;-Na carboxylate polyethylenoxide (f-PEO) has been synthesized and used as counter-ion for the synthesis of polypyrrole (PPy) films. The effect of f-PEO concentration on the kinetics of pyrrole polymerization has been studied. The ion exchange properties of the formed PPy/f-PEO composite have been analyzed in aqueous solution containing various salts (f-PEONa and LaCl3). The incorporation of indigo carmine in this type of composite has also been investigated. [less ▲]

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See detailIon-Mobility mass spectrometry as a potential tool to assign disulfide bonds arrangements in peptides with multiple disulfide bridges.
Echterbille, Julien ULg; Quinton, Loïc ULg; Gilles, Nicolas et al

in Analytical Chemistry (2013)

Disulfide bridges play a major role in defining the structural properties of peptides and proteins. However, the determination of the cysteine pairing is still challenging. Peptide sequences are usually ... [more ▼]

Disulfide bridges play a major role in defining the structural properties of peptides and proteins. However, the determination of the cysteine pairing is still challenging. Peptide sequences are usually achieved using MS/MS spectra of the totally reduced unfolded species but the cysteine pairing information is lost. On the other hand, MS/MS experiments performed on native folded species show complex spectra composed of non-classical ions. MS/MS alone does not allow the cysteine pairing nor the full sequence of an unknown peptide to be determined. The major goal of this work is to set up a strategy for the full structural characterization of peptides including disulfide bridges annotation in the sequence. This strategy was developed by combining Ion Mobility Spectrometry (IMS)and Collision Induced Dissociation(CID). It is assumed that the opening of one S-S bridges in a peptide leads to a structural evolution which results in a modification of IMS drift time. In the presence of multiple S-S bridges, the shift in arrival time will depend on which disulfide(s) has (have) been reduced and on the shape adopted by the generated species. Due to specific fragmentations observed for each species, CID experiments performed after the mobility separation could provide not only information on peptide sequence, but also on the localization of the disulfide bridges. To achieve this goal, synthetic peptides containing two disulfides were studied. The openings of the bridges were carried out following different experimental conditions such as reduction, reduction/alkylation or oxidation. Due to disulfide scrambling highlighted with the reduction approaches, oxidation of S-S bonds into cysteic acids appeared to be the best strategy. Cysteines connectivity was then unambiguously determined for the two peptides, without any disulfide scrambling interference. [less ▲]

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See detailIonic adsorption of ammonium and nitrate on some animal litters and their role in ammonia volatilization
Nimenya, H.; Delaunois, A.; Bloden, Serge ULg et al

in Annals of Zootechnology (2000), 49

Two experiments were carried out to determine the adsorption of ammonium and nitrate on litters (Exp. 1) and the volatilization of ammonia in their presence (Exp. 2). In Exp. 1, glass tubes containing 15 ... [more ▼]

Two experiments were carried out to determine the adsorption of ammonium and nitrate on litters (Exp. 1) and the volatilization of ammonia in their presence (Exp. 2). In Exp. 1, glass tubes containing 15 mi of a buffered solution enriched with NH4Clcalculated as 10.59 mg.l(-1) of NH4+ or KNO3 calculated as 50 mg.l(-1) of NO3- were used. Graded amounts (0 [control], 25, 50, 100 mg) of litters (wheat straw, nax straw (Equi-lin(R)), zeolite (Zeolite Stall Fresh(R)), spruce sawdust and beech sawdust) were added to the tubes which were incubated for 24 h. Ammonium and nitrate concentrations, and pH, were checked on the supernatant. A preliminary experiment was carried out with zeolite to come to an ammonium balance. After adsorption of ammoniumby graded amounts of zeolite, [0 (control), 0.25, 1, 2, 4 g], ammonium balance was assessed after two elutions with 1 N HCl. In Exp. 2, Woulff flasks were used and ammonia was trapped in a solution of 0.1 N HCl. The preliminary experiment showed that the ammonium added and adsorbed by different amounts of zeolite was completely recovered after 2 elutions. All litters, except beech sawdust, were effective in ammonium adsorption. Especially, the straws were required in very small amounts to immobilize the added ammonium or nitrate. Furthermore, with straws the pH value decreased from pH 7.5-7.60 to pH 6.90, and this effect was related to the amounts of material added. For each pH group, ammonia volatilization was significantly decreased (P <0.05) with straw (wheat straw, Equi-lino) as compared with their blank pH group. However, no significant decrease was observed with sawdust (spruce, beech) and zeolite [less ▲]

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See detailIonic end-capping of (semi)telechelic polymers by mesogens
Gohy, Jean-François; Sobry, Roger ULg; Van den Bossche, Guy ULg et al

in Polymer International (2000), 49(11), 1293-1301

Two methods have been used to end-cap linear polymer chains at one end or at both ends by a mesogen through ionic bonding. These polymers are designated as liquid-crystalline halato(semi)telechelic ... [more ▼]

Two methods have been used to end-cap linear polymer chains at one end or at both ends by a mesogen through ionic bonding. These polymers are designated as liquid-crystalline halato(semi)telechelic polymers (LC H(S)TPs). The first method relies on the ion exchange reaction between the metal counterion of halato(semi)telechelic polymers and an ionic mesogen. The second method is based on the proton transfer from a sulfonic or carboxylic acid end-group to a tertiary aliphatic amine, this approach being controlled by the relative pKa values of the acidic and basic groups. If the pKa difference is not large enough, strong hydrogen-bonding is observed by Fourier-transform infrared (FTIR) spectroscopy rather than proton transfer. The resulting materials have been characterized by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS). [less ▲]

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See detailIonic end-capping of (semi)telechelic polymers by mesogens: a novel route to liquid crystalline polymers
Gohy, Jean-François; Jérôme, Robert ULg

in Progress in Polymer Science (2001), 26(7), 1061-1099

A mesogenic cation has been associated with low molecular weight carboxylato- and sulfonato-(semi)telechelic polymers to form liquid crystalline halato(semi)telechelic polymers (LC H(S)TPs). Two methods ... [more ▼]

A mesogenic cation has been associated with low molecular weight carboxylato- and sulfonato-(semi)telechelic polymers to form liquid crystalline halato(semi)telechelic polymers (LC H(S)TPs). Two methods have been used to end-cap the linear polymer chains at one (or both) end(s) by a mesogen through ionic bonding. The first method relies on the ion-exchange reaction between the metal counterion of halato(semi)telechelic polymers and an ionic mesogen. The second method is based on the proton-transfer from a sulfonic or carboxylic acid end-group to a tertiary aliphatic amine, this approach being controlled by the relative pKa's of the acid and basic groups. The resulting materials have been characterized by differential scanning calorimetry (DSC), polarized optical microscopy (POM), small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS). On the basis of these experimental results, a model for the supramolecular organization of the LC H(S)TPs has been proposed. The final morphology results from the interplay of two competitive effects: the dipolar interaction of the ion-pairs known for multiplets formation and the propensity of the mesogenic moiety to form mesophases. The outcome of this competition depends on the mobility of the mesogenic counterion, i.e. on the strength of the dipolar interactions, the mobility of the polymer backbone and the mesogen/polymer ratio, which is controlled by the polymer molecular weight. A rod-like organization of the multiplets and a stretching of the polymer chains in the very close vicinity of the mesogenic core has been found in sulfonate polystyrenes, in agreement with the Eisenberg, Hird and Moore model for ionomers. The thickness of this region of restricted mobility has been estimated to 1 nm, which is the order of magnitude of the persistence length of polystyrene. Finally, LC H(S)TPs have been tested as interfacial agents in polystyrene/liquid crystal dispersions. The dipolar interactions of the ion pairs are clearly favorable to the additive localization at the polymer/LC interface. The higher polarity of the ammonium sulfonate pairs compared to the parent ammonium carboxylate ion pairs accordingly accounts for a higher interfacial activity. [less ▲]

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See detailIonic Liquids: Past, Present and Future
Robert, Thierry ULg

Scientific conference (2011, August 24)

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See detailIonic or non-ionic contrast media during coronary intervention: does it make a difference?
Legrand, Victor ULg

in European heart journal (2001), 22(5), 353-4

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See detailIonization fronts in RCW 107 (NGC 6164/5).
Danks, A. C.; Manfroid, Jean ULg

in Astronomy and Astrophysics (1977), 56

Abstract image available at: http://cdsads.u-strasbg.fr/abs/1977A&A....56..443D

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See detailIonization potentials of atoms and ions from lithium to tin (Z = 50)
Biémont, Emile ULg; Frémat, Y.; Quinet, Pascal ULg

in At. Data Nucl. Data Tables (1999), 71

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See detailIono slab monitoring service
Stankov, Stanimir; Warnant, René ULg; Stegen, Koen

Conference (2009)

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See detailIonoluminescence characterization of microwave and hot-filament CVD diamonds
Calvo Del Castillo, Helena ULg; Ruvalcaba Sil, Jose Luis; Belmont, Ernesto et al

in Physica Status Solidi A. Applications and Materials Science (2008), 205(9), 2221-2225

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See detailIonoluminescence of diamond, synthetic diamond and simulants
Calvo Del Castillo, Helena ULg; Ruvalcaba Sil, Jose Luis; Álvarez, M A[ et al

in Nuclear Instruments & Methods in Physics Research Section A (2007), 387

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See detailIonoluminescence of trivalent rare ion doped strontium barium niobate
Calvo Del Castillo, Helena ULg; Ruvalcaba-Sil, Jose Luis; Bettinelli, Marco et al

in Journal of Luminescence (2008), 128

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See detailIonoluminiscencia en minerales de interés gemológico
Calvo Del Castillo, Helena ULg; Ruvalcaba Sil, Jose Luis; Millán Chagoyén, Asunción et al

Poster (2007)

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