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See detailLe Palimpseste noir. Notes sur l’impétigo, la terreur et le cinéma américain contemporain
Tomasovic, Dick ULg

Book published by Yellow Now (2002)

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See detailPalladium-silver sol-gel catalysts for selective hydrodechlorination of 1,2-dichloroethane into ethylene - I. Synthesis and characterization
Heinrichs, Benoît ULg; Delhez, Patrice; Schoebrechts, Jean-Paul et al

in Journal of Catalysis (1997), 172(2), 322-335

Low-density xerogel Pd-Ag/SiO2 catalysts were prepared by a cogelation of tetraethoxysilane with organically substituted alkoxides capable of forming chelates with palladium and silver ions, followed by a ... [more ▼]

Low-density xerogel Pd-Ag/SiO2 catalysts were prepared by a cogelation of tetraethoxysilane with organically substituted alkoxides capable of forming chelates with palladium and silver ions, followed by a drying under vacuum, a calcination, and a reduction. The resulting Pd-Ag alloy particles have diameters of about 2-3 nm and are dispersed inside the silica particles which exhibit a monodisperse micropore size distribution centered at 0.8 nm. At low silver loading, the composition of the bimetallic particles is almost identical to the overall composition, but when this loading is increased, the percentage of silver in the alloy particles is appreciably lower than the overall percentage, In all bimetallic samples, a few large pure silver particles are observed. When dried under vacuum, the xerogels exhibit a texture similar to that of aerogels dried under supercritical conditions with pore volumes in the range 2-6 cm(3)/g and pores ranging from micro- to macropores of several hundred nanometers. When the silver loading is increased, xerogels containing palladium show aggregates of increasingly interpenetrated silica particles. This is explained bq an aggregation, during the gelation reaction, of colliding SiO2 particles which is limited by an increasingly slow sticking reaction due to the growing basicity in the precursor solution when the concentrations of Ag and associated compounds are increased. During thermal treatments, the Pd-Ag alloy seems to form by the migration, through the porous network, of silver which finally alloys with Pd crystallites trapped inside SiO2 particles. Whereas ethane is the main product when hydrodechlorination of 1,2-dichloroethane is performed over pure palladium, the dilution of this active metal by silver leads to a strong increase in ethylene selectivity. (C) 1997 Academic Press. [less ▲]

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See detailPalladium-silver sol-gel catalysts for selective hydrodechlorination of 1,2-dichloroethane into ethylene - IV. Deactivation mechanism and regeneration
Heinrichs, Benoît ULg; Noville, Francis ULg; Schoebrechts, Jean-Paul ULg et al

in Journal of Catalysis (2003), 220(1), 215-225

The activity and selectivity of a 1.9% Pd-3.7% Ag/SiO2 catalyst during selective hydrodechlorination of 1,2-dichloroethane into ethylene have been followed in the course of time. The deactivation curves ... [more ▼]

The activity and selectivity of a 1.9% Pd-3.7% Ag/SiO2 catalyst during selective hydrodechlorination of 1,2-dichloroethane into ethylene have been followed in the course of time. The deactivation curves show two distinct periods: an initial period at the very beginning of catalyst operation, that is, during the first 20 operating hours, characterized by a sharp decrease of the rates of both reactions involved in the process (1,2-dichloroethane hydrodechlorination and undesired ethylene hydrogenation) and a second period, after the first 20 operating hours and investigated for more than 600 h, characterized by a clearly slower deactivation. During the initial period, the hydrodechlorination rate decreases less quickly than the hydrogenation rate and this results in a fast increase of ethylene selectivity which reaches a maximum at the end of this period. After the initial period, the hydrodechlorination rate decreases faster than the hydrogenation rate and this results in a slow decrease of ethylene selectivity. A comparison between the physico-chemical properties of the fresh catalyst and of the deactivated one suggests a deactivation mechanism by poisoning or coking of silver sites at the surface of the active Pd-Ag alloy particles whereas palladium sites would remain intact. The selectivity evolution during the second period, that is, after the very first operating hours, is in agreement with such a mechanism. However, the sharp ethylene selectivity increase during the initial operating hours suggests, in addition to the deactivation by silver sites disappearance, the presence of a further nonidentified phenomenon. The characterization of the catalyst after a regeneration treatment including an oxidation step followed by a reduction step shows that this treatment allows restoration near to the physico-chemical properties of the fresh catalyst. (C) 2003 Elsevier Inc. All rights reserved. [less ▲]

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See detailPalladium-silver sol-gel catalysts for selective hydrodechlorination of 1,2-dichloroethane into ethylene II. Surface composition of alloy particles
Heinrichs, Benoît ULg; Noville, Francis ULg; Schoebrechts, Jean-Paul et al

in Journal of Catalysis (2000), 192(1), 108-118

The surface composition of alloy particles in Pd-Ag/SiO2 hydrodechlorination (HDC) sol-gel catalysts has been determined by combining three experimental techniques, carbon monoxide chemisorption, X-ray ... [more ▼]

The surface composition of alloy particles in Pd-Ag/SiO2 hydrodechlorination (HDC) sol-gel catalysts has been determined by combining three experimental techniques, carbon monoxide chemisorption, X-ray diffraction, and transmission electron microscopy, Values obtained through this method show a very marked silver enrichment of the surface, as expected: as a consequence of the important gap between palladium and silver surface energies. These values are in complete agreement with surface composition curves calculated in other studies by means of Auger electron spectroscopy and infrared spectroscopy. The influence of sample pretreatment temperature as well as the influence of carbon monoxide on surface composition are discussed. (C) 2000 Academic Press. [less ▲]

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See detailPalladium-silver sol-gel catalysts for selective hydrodechlorination of 1,2-dichloroethane into ethylene III. Kinetics and reaction mechanism
Heinrichs, Benoît ULg; Schoebrechts, Jean-Paul; Pirard, Jean-Paul ULg

in Journal of Catalysis (2001), 200(2), 309-320

The kinetics of selective hydrodechlorination of 1,2-dichloro-ethane into ethylene over a Pd-Ag/SiO2 catalyst is studied. Kinetic data at 573, 596, and 647 K have been obtained by means of experimental ... [more ▼]

The kinetics of selective hydrodechlorination of 1,2-dichloro-ethane into ethylene over a Pd-Ag/SiO2 catalyst is studied. Kinetic data at 573, 596, and 647 K have been obtained by means of experimental designs in the space of the partial pressures of the four components influencing kinetics, that is, 1,2-dichloroethane, hydrogen, ethylene, and hydrogen chloride. One model among the numerous ones examined allows us to represent correctly the experimental data. Ii: corresponds to the following mechanism: dechlorination of 1,2-dichloroethane into ethylene occurs on silver through dissociative adsorption with successive breaking of the two C-Cl bonds and desorption of C2H4. Thanks to its activation power of hydrogen by dissociative chemisorption, palladium present at the surface of the alloy supplies hydrogen atoms for regeneration of the chlorinated silver surface into metallic silver. The presence of hydrogen adsorbed on Pd also causes the undesired ethylene hydrogenation leading to a loss of olefin selectivity. (C) 2001 Academic Press. [less ▲]

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See detailPalliative sedation: Why we should be more concerned about the risks that patients experience an uncomfortable death
Deschepper, R; Laureys, Steven ULg; Hachimi-Idrissi, S et al

in Pain (2013), Vol 154

[No abstract available]

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See detailLe palmarès des communes n'est pas un classement tangible
Dubois, Olivier; Jurion, Bernard ULg; Husson, Jean-François ULg

Article for general public (2006)

This paper discusses some ranking of Belgian municipalities produced by some researchers.

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See detailThe Palmomental Reflex in Parkinson's Disease. Comparisons with Normal Subjects and Clinical Relevance
Maertens De Noordhout, Alain ULg; Delwaide, Paul ULg

in Archives of Neurology (1988), 45(4), 425-7

We tested 356 normal subjects and 109 parkinsonian patients for the palmomental reflex. The total incidence of the reflex was 16.3% in normal subjects, increasing with age. In parkinsonian patients, the ... [more ▼]

We tested 356 normal subjects and 109 parkinsonian patients for the palmomental reflex. The total incidence of the reflex was 16.3% in normal subjects, increasing with age. In parkinsonian patients, the overall incidence of the reflex was 71.5%, without clear effect of age. A positive correlation was found between degree of akinesia and incidence as well as intensity of the reflex. In the dyskinetic patients, the reflex was seldom elicited, and, if so, it was small. Modifications of the characteristics of the response could be disclosed in parallel with variations of the patient's clinical status. These findings suggest that the presence of a palmomental reflex in parkinsonian patients could indirectly reflect the decrease of dopaminergic activity in the nigrostriatal pathways. [less ▲]

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See detailPalynological age for the lower part of the Hangenberg Shales in Sauerland, Germany
Higgs, K; Streel, Maurice ULg

in Annales de la Société Géologique de Belgique (1993), 116(Z), 243-247

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See detailPalynological and geochemical data in peat sediments at the side of an old (Roman to / or Merovingian) paved road in the Hautes-Fagnes.
Streel, Maurice ULg; Renson, V; De Vleeschouwer, F

in Carnets de Géologie = Notebooks on Geology (2007), 2007/01(9), 8

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See detailPalynological characterization and dating of the Tiangua Formation, Serra Grande Group, northern Brazil
Le Hérissé, A.; Melo, J. H. G.; Quadros, L. P. et al

in Melo, J.H.G.; Terra, G.I.S. (Eds.) Correlaçâo de Seqüências Paleozóicas Sul-Americanas (2001)

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See detailPalynological characterization and dating of the Tiangua Formation, Serra Grande Group, Paranaiba Basin, northern Brazil
Quadros, L. P.; Grahn, Y.; Melo, J. H. G. et al

Conference (2000)

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See detailPalynological data from the Devonian-Carboniferous boundary beds in the new Stockum trench II and the Hasselbachtal borehole, northern Rhenish Massif, Germany
Higgs, K; Streel, Maurice ULg; Korn, D et al

in Annales de la Société Géologique de Belgique (1992), 115(2), 551-557

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See detailPalynological data from the Devono-Carboniferous boundary beds in the new Stockum Trench II and the Hasselbachtal Borehole. Northern Rhenish Massif, Germany.
Higgs, K; Streel, Maurice ULg; Korn, D et al

in Annales de la Société Géologique de Belgique (1993), 115(2/1992), 551-557

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See detailPalynological evaluation of the Famennian Protosalvinia (Foerstia) Zone in the Amazon basin, Northern Brazil : a preliminary study.
Loboziak; Melo, J.H.G.; Quadros, L.P. et al

in Review of Palaeobotany and Palynology (1997), 96

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See detailPalynological Events in the Mississippian (Lower Carboniferous) of Europe, North Africa and North America.
Clayton, G; Loboziak, S; Streel, Maurice ULg et al

in Courier Forschungsinstitut Senckenberg (1990), 130

Detailed reference viewed: 18 (0 ULg)
See detailPalynological study of the deep portion of the Porcheresse-Havelange borehole
Steemans, Philippe ULg; Graulich, J. M.

Conference (1985)

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See detailPalynologie de la région et du sondage de Willerzie
Roche, Marc ULg; Sabir, M; Steemans, Philippe ULg et al

in Aardkundige Mededelingen (1986), 3

Detailed reference viewed: 30 (4 ULg)