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See detailDetermination of surface composition of alloy nanoparticles and relationships with catalytic activity in Pd-Cu/SiO2 cogelled xerogel catalysts
Lambert, Stéphanie ULg; Heinrichs, Benoît ULg; Brasseur, Alain et al

in Applied Catalysis A : General (2004), 270(1-2), 201-208

The combination of results from carbon monoxide chemisorption, X-ray diffraction, and transmission electron microscopy allowed calculating the surface composition of the palladium-copper nanoparticles in ... [more ▼]

The combination of results from carbon monoxide chemisorption, X-ray diffraction, and transmission electron microscopy allowed calculating the surface composition of the palladium-copper nanoparticles in Pd-Cu/SiO2 cogelled xerogel catalysts. Values obtained indicate a very pronounced surface enrichment with copper. Surface compositions obtained with this method, which combines three different experimental techniques, are in agreement with the literature data previously obtained for surface segregation in Pd-Cu/SiO2 catalysts by other techniques as low energy ion scattering and X-ray photoelectron spectroscopy. While 1,2-dichloroethane hydrodechlorination over pure palladium mainly produces ethane, increasing copper content in bimetallic catalysts results in an increase in ethylene selectivity, to reach 100% in ethylene selectivity for the sample containing 1.4 wt.% of palladium and 3.0 wt.% of copper. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailDetermination of Tear Break-up Time reference values and ocular tolerance of tetracaine hydrochloride eyedops in healthy horses
Monclin, Sébastien ULg; Farnir, Frédéric ULg; Grauwels, Magda ULg

in Equine Veterinary Journal (2011), 43(1), 74-77

REASONS FOR PERFORMING STUDY: Tetracaine hydrochloride (THCl) has been reported to cause irritation in dogs. In man, some topical anaesthetics have been shown to disrupt the tear film. Tear break-up time ... [more ▼]

REASONS FOR PERFORMING STUDY: Tetracaine hydrochloride (THCl) has been reported to cause irritation in dogs. In man, some topical anaesthetics have been shown to disrupt the tear film. Tear break-up time (TBUT) is a useful test allowing an assessment of the quality of the precorneal tear film. Only one TBUT value has been reported in horses with no information on the technique used. OBJECTIVES: To provide a method for performing the TBUT in horses and to report any side effects of a single application of THCl in clinically normal horses, particularly on the stability of the tear film. METHODS: In Study 1, one drop of 0.5 or 1% THCl was applied to one eye of 20 horses divided in 2 groups. Treated eyes were assessed for the development of side effects 2.5 and 5 min after treatment. In Study 2, the TBUT was measured in both eyes of 2 groups of 10 horses, before and 2.5 and 5 min after, instillation of one drop of either 0.5 or 1% THCl. RESULTS: No animals developed any ocular side effect after instillation. Basal TBUT was 8.3±1.3 s. TBUT decreased from baseline 5 and 2.5 min after application of one drop of 0.5% THCl and one drop of 1% THCl, respectively. CONCLUSIONS: A technique to measure the TBUT in healthy horses is described and normal range values that could be used as a reference were obtained. POTENTIAL RELEVANCE: THCl is well tolerated in horses but lowers the TBUT. [less ▲]

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See detailDetermination of TGF-β1 plasma levels. Authors' reply
Barthelemy, Nicole ULg; De Jaeger, Katrien; SEPPENWOOLDE, Yvette et al

in International Journal of Radiation, Oncology, Biology, Physics (2004), 60(4), 1339

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See detailDetermination of the Al2O3 content in NaF-AlF 3-CaF2-Al2O3 melts at 950 °c by raman spectroscopy
Malherbe, Cédric ULg; Eppe, Gauthier ULg; Gilbert, Bernard ULg

in Analytical Chemistry (2014)

Thein situ control of the chemical composition of industrial aluminum smelter is a challenge mainly for physicochemical reasons: high temperature, high surrounding electromagnetic field, and the highly ... [more ▼]

Thein situ control of the chemical composition of industrial aluminum smelter is a challenge mainly for physicochemical reasons: high temperature, high surrounding electromagnetic field, and the highly corrosive molten salt electrolyte to deal with. In previous works, we proposed that Raman spectroscopy is a method of choice that could be adapted to real smelters. The laboratory study presented here relies on reproducible Raman spectra recorded on molten mixtures whose compositions are identical to those used during the production of aluminum. A normalization procedure for the Raman spectra is proposed based on the equilibria taking place in the bath. In addition, we discuss two quantitative models to determine the alumina content from the Raman spectra of the molten NaF−AlF3−CaF2−Al2O3 electrolytes. Univariate and multivariate approaches are applied to determine both theCOx (alumina content) and the CR (NaF/AlF3 molar ratio) by Raman spectroscopy without referring to an additional internal reference of intensity. The procedure was successfully tested and validated on industrial samples. [less ▲]

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See detailDetermination of the antimony valence state in Eu10Mn6Sb13
Brown, D. E.; Johnson, C. E.; Grandjean, Fernande ULg et al

in Inorganic Chemistry (2004), 43(4), 1229-1234

The antimony-121 Mossbauer spectra of Eu10Mn6Sb13 have been measured between 2 and 295 K. Although the Zintl formalism indicates that the nine crystallographically distinct antimony sites in Eu10Mn6Sb13 ... [more ▼]

The antimony-121 Mossbauer spectra of Eu10Mn6Sb13 have been measured between 2 and 295 K. Although the Zintl formalism indicates that the nine crystallographically distinct antimony sites in Eu10Mn6Sb13 should have formal valence states of -2, -1, 0, and +1, the Mossbauer spectral isomer shifts reveal that the valence states of the 4.0 different sites are all quite similar and correspond to an average electronic configuration for antimony of 5s(1.7)5p(4.0). This configuration corresponds to an excess of negative charge on the antimony of 0.7 or an average valence of -0.7, a valence which is rather consistent with the average antimony valence of -0.61 obtained from the Zintl formalism for the nine antimony sites in Eu10Mn6Sb13. The spectra obtained between 90 and 295 K are more consistent with the absence rather than the presence of any transferred magnetic hyperfine field at the antimony. In contrast, the spectra obtained at 2 and 5 K reveal the presence of an average transferred magnetic hyperfine field of ca. 8 T, a field that arises from the ferromagnetic ordering of the near-neighbor manganese(II) ions. [less ▲]

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See detailDetermination of the complete bifurcation behaviour of aeroelastic systems with freeplay
Dimitriadis, Grigorios ULg

Scientific conference (2010, November 09)

In recent years there have been several applications of the nonlinear numerical continuation approach to aeroelastic systems with freeplay. While some of these have been successful, the general ... [more ▼]

In recent years there have been several applications of the nonlinear numerical continuation approach to aeroelastic systems with freeplay. While some of these have been successful, the general application of the method to such systems remains problematic. Numerical continuation can fail in the presence of complex bifurcations, numerous nearby periodic solution branches and other factors. In this paper, a three-part procedure for applying numerical continuation to aeroelastic systems with freeplay is proposed, designed to ensure that the complete periodic behavior is identified, even for systems with complex bifurcation diagrams. First, the equivalent linearization approach is used to determine approximations to the periodic solution branches of the nonlinear system. Then, a shooting-based technique is applied separately to each linearized approximation in order to pinpoint the nearest exact periodic solution. This process results in a cloud of periodic solutions, representing all the branches and sub-branches. Finally, a branch-following shooting procedure is applied to this cloud of points in order to obtain a complete description of every branch of periodic solutions. The procedure is demonstrated on a simple 3-DOF mathematical aeroelastic system with freeplay; it is shown that an extremely complex bifurcation is fully captured. The system's bifurcation diagram features multiple branch crossings, folds and loops. Its complete calculation allows the justification of several interesting LCO phenomena, such as aperiodic LCOs. [less ▲]

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See detailDetermination of the composition of cryolitic melts involved in the Hall-Heroult process by Raman spectroscopy
Malherbe, Cédric ULg; Gilbert, Bernard ULg

Conference (2012, August)

Considering our experience in the study of such highly corrosive media by Raman spectroscopy and since the bath spectrum is function of the molar NaF/AlF3 ratio and the Al2O3 content, we have proposed in ... [more ▼]

Considering our experience in the study of such highly corrosive media by Raman spectroscopy and since the bath spectrum is function of the molar NaF/AlF3 ratio and the Al2O3 content, we have proposed in the past to apply that technique to the direct determination of the melt composition . Recent instrumental developments on CCD based spectrometers have made the proposed method more feasible. This presentation will first demonstrate that, employing an updated instrument provided with new optical filters and a more sensitive CCD detector, better quality spectra are obtained. Afterward, new results relevant to the development of our analytical method for the direct determination of the molar NaF/AlF3 ratio and the Al2O3 content in cryolitic melt will be discuss. Different aspects of the calculation procedure will be illustrated:  Estimation and subtraction method of the Rayleigh decay from melt spectra;  Development of an internal normalisation procedure based on equilibria in the melt and assisted by home-made software;  Establishment of calibration curves for the determination of the molar ratio NaF/AlF3 in the melt;  Establishment of calibration curves for the determination of oxide content in the melt;  Overall procedure for the composition determination. [less ▲]

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See detailDetermination of the constants of the diurnal nutation
Folie, François ULg

in Science (1895), 2(45), 613-617

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See detailDetermination of the coordination number of particulate nano-materials using nitrogen adsorption
Gommes, Cédric ULg; Ravikovitch, Peter; Neimak, Alex

Scientific conference (2008, April)

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See detailDetermination of the Cosmological Density of Compact Objects using Gravitational Lensing and the HST
Claeskens, Jean-François ULg; Surdej, Jean ULg

in Benvenuti, Piero; Macchetto, F. D.; Schreier, E. J. (Eds.) Science with the Hubble Space Telescope - II (1996)

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See detailDetermination of the Enantiomers of 3-Tert.-Butylamino-1,2-Propanediol by High-Performance Liquid Chromatography Coupled to Evaporative Light Scattering Detection
Toussaint, B.; Duchateau, A. L.; van der Wal, S. et al

in Journal of Chromatography. A (2000), 890(2), 239-49

A method for the separation and quantitation of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography and evaporative light scattering detection has been ... [more ▼]

A method for the separation and quantitation of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography and evaporative light scattering detection has been developed. Separation of the enantiomers was performed in normal-phase liquid chromatography on a Chiralpak AS chiral stationary phase. The influence of the gas nature, gas pressure and temperature of the drift tube of the evaporative light scattering detector on the detection sensitivity was investigated. The method was validated in terms of linearity, limit of quantitation, accuracy and precision. The enantiomeric excess of (S)-3-tert.-butylamino-1,2-propanediol, used for the industrial synthesis of (S)-timolol, was measured from 0 to 94%. [less ▲]

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See detailDetermination of the Enantiomers of 3-Tert.-Butylamino-1,2-Propanediol by High-Performance Liquid Chromatography Using Mass Spectrometric Detection
Toussaint, B.; Streel, B.; Ceccato, Attilio ULg et al

in Journal of Chromatography. A (2000), 896(1-2), 201-7

The chiral synthesis of beta-blockers such as (S)-timolol requires a sensitive analytical method for the enantioseparation of its intermediate, 3-tert.-butylamino-1,2-propanediol, in the ng/ml range. The ... [more ▼]

The chiral synthesis of beta-blockers such as (S)-timolol requires a sensitive analytical method for the enantioseparation of its intermediate, 3-tert.-butylamino-1,2-propanediol, in the ng/ml range. The method developed is based on on-line normal-phase LC-MS-MS using a chiral stationary phase and an atmospheric pressure chemical ionization (APCI) interface. The MS detection of 3-tert.-butylamino-1,2-propanediol was first optimized with a pneumatically-assisted electrospray interface (ionspray). The APCI interface was then selected for LC-MS-MS because of the incompatibility of electrospray with n-hexane. The method was validated for both enantiomers in the 25-500 ng/ml concentration range. [less ▲]

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See detailDetermination of the environmental footprint of the anthropic water cycle using LCA
Groslambert, Sylvie ULg; Léonard, Angélique ULg

Poster (2014, May)

The aim of this study is to describe the development of a life cycle assessment of drinking water in the Walloon Region, in Belgium. This study also includes rainwater harvesting as a complement to tap ... [more ▼]

The aim of this study is to describe the development of a life cycle assessment of drinking water in the Walloon Region, in Belgium. This study also includes rainwater harvesting as a complement to tap water. Data collected for this report are based on information available for 2010 as reference year. The functional unit is 1 m³ of water used by a Walloon citizen (including both rainwater and drinking water). [less ▲]

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See detailDetermination of the Expansion Rate and Incidence of Rupture of Abdominal Aortic Aneurysms
Limet, Raymond ULg; Sakalihasan, Natzi ULg; Albert, Adelin ULg

in Journal of Vascular Surgery : Official Publication, the Society for Vascular Surgery and International Society For Cardiovascular Surgery, North American Chapter (1991), 14(4), 540-8

Expansion rate and incidence of rupture of abdominal aortic aneurysms in relation to their size is a source of debate. We studied 114 patients (out of a cohort of 752 consecutive patients admitted with ... [more ▼]

Expansion rate and incidence of rupture of abdominal aortic aneurysms in relation to their size is a source of debate. We studied 114 patients (out of a cohort of 752 consecutive patients admitted with abdominal aortic aneurysms) who were denied any immediate operation because of patient's refusal, high surgical risk, or small transverse diameter as assessed by CT scanning and ultrasonography. All patients not operated on underwent from two to six repeated examinations during an average follow-up period of 26.8 months (range, 3 to 132). Forty-seven patients (41.2%) were subsequently operated on electively because of marked increase of transverse diameter of the aneurysm (n = 44) or for other reasons (n = 3), with a death rate of 0%. Eighteen other patients underwent emergency operation for leaking or ruptured aneurysms, and there were five deaths. The incidence of rupture was clearly related to the final diameter value, rising from 0% in aneurysms less than 40 mm to 22% in large size aneurysms (greater than or equal to 50 mm). Among the 49 patients not operated on, one died of rupture before operation and five of causes unrelated to the disease. Using individual serial measurements, we determined the linear expansion rate of the aneurysm, which proved to be related to initial diameter values: 5.3 mm/year for diameters less than 40 mm (n = 49), 6.9 mm/year in the 40 to 49 mm group (n = 41), and 7.4 mm/year for diameters of 50 mm or more (n = 24).(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

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