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See detailExperimental and theoretical transition probabilities in singly ionized gold
Biémont, Emile ULg; Blagoev, K.; Fivet, V. et al

in Monthly Notices of the Royal Astronomical Society (2007), 380(4), 1581-1588

Absolute transition probabilities have been measured for lines originating from the 5d(9)6d and 5d(9)7s electronic configurations in the spectrum of singly ionized gold (Au II). The laser-induced ... [more ▼]

Absolute transition probabilities have been measured for lines originating from the 5d(9)6d and 5d(9)7s electronic configurations in the spectrum of singly ionized gold (Au II). The laser-induced breakdown spectroscopy has been applied to free gold atoms and ions produced by laser ablation. Absolute transition probabilities have been determined using the branching fraction and the Boltzmann plot methods. Theoretical branching fractions as well as radiative lifetime values have also been obtained by a relativistic Hartree-Fock method taking core polarization and configuration interaction effects into account. The new results are compared with previous results when available. [less ▲]

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See detailExperimental anti-angiogenesis causes upregulation of genes associated with poor survival in glioblastoma.
Saidi, Ahlame; Javerzat, Sophie; Bellahcene, Akeila ULg et al

in International Journal of Cancer = Journal International du Cancer (2008), 122(10), 2187-98

Vascular endothelial growth factor (VEGF) inhibitors are the most promising anti-angiogenic agents used increasingly in the clinic. However, to be efficient, anti-VEGF agents need to be associated with ... [more ▼]

Vascular endothelial growth factor (VEGF) inhibitors are the most promising anti-angiogenic agents used increasingly in the clinic. However, to be efficient, anti-VEGF agents need to be associated with classic chemotherapy. Exploring gene regulation in tumor cells during anti-angiogenesis might help to comprehend the molecular basis of response to treatment. To generate a defined anti-angiogenic condition in vivo, we transfected human glioma cells with short-interfering RNAs against VEGF-A and implanted them on the chick chorio-allantoic membrane. Gene regulation in avascular tumors was studied using human Affymetrixtrade mark GeneChips. Potentially important genes were further studied in glioma patients. Despite strong VEGF inhibition, we observed recurrent formation of small, avascular tumors. CHI3L2, IL1B, PI3/elafin and CHI3L1, which encodes for YKL-40, a putative prognosticator for various diseases, including cancer, were strongly up-regulated in avascular glioma. In glioblastoma patients, these genes showed coregulation and their expression differed significantly from low-grade glioma. Importantly, high levels of CHI3L1 (p = 0.036) and PI3/elafin mRNA (p = 0.0004) were significantly correlated with poor survival. Cox regression analysis further confirmed that PI3 and CHI3L1 levels are survival markers independent from patient age and sex. Elafin-positive tumor cells were only found in glioblastoma, where they were clustered around necrotic areas. PI3/elafin is strongly induced by serum deprivation and hypoxia in U87 glioma cells in vitro. Our results indicate that anti-angiogenesis in experimental glioma drives expression of critical genes which relate to disease aggressiveness in glioblastoma patients. In particular, CHI3L1 and PI3/elafin may be useful as new prognostic markers and new therapeutic targets. [less ▲]

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See detailAn experimental approach for synthesis of Fe-Al-O multiferroic fibrous material
Starbov, N; Starbova, K; Vanderbemden, Philippe ULg et al

in Journal of Physics: Conference Series (2012), 398

Basic principles of the electro-hydrodynamics are applied for synthesis of solid state Fe-Al-O multi-ferroic fibrous material. For that purpose stable blend spinning solutions comprised of a high ... [more ▼]

Basic principles of the electro-hydrodynamics are applied for synthesis of solid state Fe-Al-O multi-ferroic fibrous material. For that purpose stable blend spinning solutions comprised of a high molecular assisting organic polymer and salts of iron and aluminum are developed. These solutions are tested under electrospinning conditions and synthesis of homogeneous as spun non-woven mats characterized by fibre mean diameters in the microand nano-size range is successfully demonstrated. Multi-step thermal procedure is applied for the consecutive solvent evaporation, polymer pyrolisis and final fibre calcination. Electronoptical imaging technique and XRD are applied for revealing the sample morphology and the phase composition correspondingly. The results obtained outline the wide possibilities for fabrication of multi-ferroics fibrous nano-materials on the basis of Fe-Al-O. [less ▲]

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See detailExperimental approach of the behavioural spawning tactics in Barbus meridionalis using paternity analysis.
Binda, O.; Poncin, Pascal ULg; Chenuil, A. et al

Poster (1997)

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See detailAn Experimental Approach to Link Powder Physical Properties to 3D Particle Shape
Califice, Arnaud ULg; Lumay, Geoffroy ULg; Vandewalle, Nicolas ULg et al

in Particulate Systems Analysis 2011 (2011, September)

A series of samples have been characterized by 3D image analysis (using X-Ray microtomography). The samples consist of blends of metallic particles: steel shot abrasives (“balls”), steel fibres and ... [more ▼]

A series of samples have been characterized by 3D image analysis (using X-Ray microtomography). The samples consist of blends of metallic particles: steel shot abrasives (“balls”), steel fibres and angular steel grit particles. The blends were systematically prepared in different proportions of the raw products. Various shape and size parameters were measured on the particles: equivalent volume diameter (dV), maximum inscribed sphere diameter (dIN), particle length (maximum Feret diameter), particle elongation (El), particle flatness (Fl) etc. The results are expressed as statistical shape and size parameters, expressed both as volume and number weighted distributions. The blends have been tested for compaction using a cylindrical container which experiences a series of 500 free falls over a height of 3mm. The compaction dynamics was monitored using a sensor that measures the evolution of the solid volume fraction as a function of the tap number. From the obtained compaction curve, the Hausner ratio and a flowability index were extracted. The same blends have also been analysed using a rotating drum at different rotation speeds to analyze the evolution of the flowing angle. As the system is based on the analysis of a time sequence of 50 images (separated by 0.5 sec) it is possible to measure the intermittent character of the powder flow. The resulting measure is a cohesive index of the powder. The results obtained from physical testing were systematically plotted as a function of various statistical indices of the shape and size distributions in order to reveal correlations between particle shape properties and physical behaviour. Some clear trends appeared, demonstrating the influence of particle shape on powder physical properties. [less ▲]

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See detailExperimental assement of the effect of the real flame emissivity for steel elements engulfed into fire
Tondini, Nicola; Vassart, Olivier; Franssen, Jean-Marc ULg

in xxx (in press)

This paper presents the results of an experimental campaign performed to assess the effect of the flame emissivity for steel members engulfed into fire. In detail, two sizes of circular steel tubes were ... [more ▼]

This paper presents the results of an experimental campaign performed to assess the effect of the flame emissivity for steel members engulfed into fire. In detail, two sizes of circular steel tubes were engulfed into pool fires of two different diameters. Two fuels were used and for both fuels tests without column (used as comparison with existing localised fire models) and with column were performed. The temperature of the column and of the flames were measured at different heights. The width of the flame was also measured and used to calculate the emissivity of the flame the value of which was employed in numerical simulations in order to predict the evolution of the temperature of the steel column. Comparison with numerical analyses where the recommended values of the Eurocode were used is also shown. [less ▲]

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See detailEXPERIMENTAL CHALLENGES TO THE STANDARD MODEL: A REEVALUATION
Cudell, Jean-René ULg

Doctoral thesis (1987)

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See detailExperimental characterisation and modelling of homogeneous solid suspension in an industrial stirred tank
Calvo, Sébastien ULg; Delafosse, Angélique ULg; Collignon, Marie-Laure ULg et al

in Advances in Mechanical Engineering (2013), Volume 2013

In this work, we study the conditions needed to reach homogeneous distribution of aluminium salts particles in water inside a torispherical bottom shaped stirred tank of 70 L equipped with a Pfaudler RCI ... [more ▼]

In this work, we study the conditions needed to reach homogeneous distribution of aluminium salts particles in water inside a torispherical bottom shaped stirred tank of 70 L equipped with a Pfaudler RCI type impeller and three equispaced vertical baffles. The aim of the present study is to develop a CFD model describing the quality of particle distribution in industrial scale tanks. This model, validated with experimental data, is used afterwards to develop scale-up and scale-down correlations to predict the minimum impeller speed needed to reach homogeneous solid distribution Nhs.The commercial CFD software Fluent 14 is used to model the fluid flow and the solid particle distribution in the tank. Sliding Mesh approach is used to take the impeller motion into account. Assuming that the discrete solid phase has no influence on the continuous liquid phase behaviour, the fluid flow dynamics is simulated independently using the well-known k-ε turbulence model. The liquid-solid mixture behaviour is then described by implementing the Eulerian Mixture model. Computed liquid velocity fields are validated by comparison with PIV measurements. ComputedNhs were found to be in good agreement with experimental measurements. Results fromdifferent scales allowed correlating Nhs values to the volumetric power consumption. [less ▲]

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See detailExperimental Characterisation of Damage Occuring during Single Point Incremental Forming of a Ferritic Steel
Mertens, Anne ULg; Guzmán Inostroza, Carlos Felipe ULg; Habraken, Anne ULg et al

Poster (2012, September)

Single Point Incremental Forming (SPIF) has been developed as a new dieless process for forming metal sheets. This technique appears very promising in view of the current requirements for rapid ... [more ▼]

Single Point Incremental Forming (SPIF) has been developed as a new dieless process for forming metal sheets. This technique appears very promising in view of the current requirements for rapid prototyping and/or small series production [1]. However, inaccuracies in the shape of the processed part and material failure constitute important limiting factors for applications. In the present research, a numerical approach, based on the damage model proposed by Gurson [2], has been chosen to analyse and optimise the process, predict the material rupture and the process limit. From experimental observations of plastic deformation and ductile fracture, damage is related to the nucleation, growth and coalescence of microvoids [3]. Gurson’s model uses the volume fraction of these voids as a main variable. Hence the determination of this value is a key factor for a correct identification and validation of the model. More particularly, the present work focuses on two different methods used to experimentally characterise damage occurring during single point incremental forming of a ferritic steel. Void measurements carried out by optical microscopy combined with image analysis have been compared with porosity values obtained from density measurements based on the Archimedes’ principle [4], so as to assess the feasibility of using this method for a quick characterisation of the damage. [less ▲]

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See detailExperimental characterization and constitutive modeling of TA6V mechanical behavior in plane strain state at room temperature
Gilles, Gaëtan ULg; Tuninetti Vásquez, Victor ULg; Ben Bettaieb, Mohamed ULg et al

in AIP Conference Proceedings (2011), 1383

This paper presents an experimental and theoretical study of the quasi-static behavior of TA6V titanium alloy in plane strain state. In order to quantify the anisotropy of the material, tests were carried ... [more ▼]

This paper presents an experimental and theoretical study of the quasi-static behavior of TA6V titanium alloy in plane strain state. In order to quantify the anisotropy of the material, tests were carried out at room temperature on specimens cut out from a sheet along three loading directions. The initial yield locus is described by the phenomenological CPB06ex3 criterion and Voce’s type isotropic hardening is used. Finite element simulations are performed and compared with the experiments. [less ▲]

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See detailExperimental characterization and elasto-plastic modeling of the quasi-static mechanical response of TA-6 V at room temperature
Gilles, Gaëtan ULg; Hammami, Walid ULg; Libertiaux, Vincent ULg et al

in International Journal of Solids & Structures (2011), 48(9), 12771289

The paper presents an experimental study of the quasi-static deformation behavior of a TA-6V in sheet form. To quantify the plastic anisotropy and the tension-compression asymmetry of this material at ... [more ▼]

The paper presents an experimental study of the quasi-static deformation behavior of a TA-6V in sheet form. To quantify the plastic anisotropy and the tension-compression asymmetry of this material at room temperature, monotonic tensile and compressive tests were carried out on specimens cut out along several orientations in the plane of the sheet. It was observed that although the tensile flow stress anisotropy is very mild, the Lankford coefficients’ anisotropy is very pronounced. To describe the observed mechanical response an elastic/plastic approach was used. Yielding was described using a family of yield criteria that account for strength differential effects and allow an improved description of the anisotropy and its evolution through multiple linear transformations. Comparisons between uniaxial monotonic data and FE simulations using the model show a very good agreement. [less ▲]

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See detailExperimental characterization of a hermetic scroll expander for use in a micro-scale Rankine cycle
Lemort, Vincent ULg; Declaye, Sébastien ULg; Quoilin, Sylvain ULg

in Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy (2011)

This paper presents the results of an experimental study carried out on a prototype of a hermetic scroll expander, integrated into a gas cycle test rig, whose working fluid is HFC-245fa. This system was ... [more ▼]

This paper presents the results of an experimental study carried out on a prototype of a hermetic scroll expander, integrated into a gas cycle test rig, whose working fluid is HFC-245fa. This system was designed to test only the performance of the expander. It is mainly made up of a scroll compressor, a scroll expander, a heat exchanger and a by-pass valve. The latter is used to adjust the pressure ratio imposed to the expander. The expander is originally a compressor designed for heat pump applications and characterized by a nominal power input of 2.5 kWe. Performance of the expander is evaluated in terms of isentropic effectiveness and filling factor as function of the main operating conditions. The study also investigates the impact of oil mass fraction on the expander performance. Maximum overall isentropic effectiveness of 71.03% is measured, which is partly explained by the good volumetric performance of the machine. Using the experimental data, parameters of a semi-empirical simulation model of the expander are identified. This model is used to analyze the measured performance of the expander. Finally, a polynomial empirical model of the expander is proposed for fast and robust simulations of ORC systems. [less ▲]

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See detailExperimental characterization of hafting traces and their recognition in archaeological assemblages
Rots, Veerle ULg; Vermeersch, Pierre M.

in Walker, E. A.; Wenban-Smith, F.; Healy, F. (Eds.) Lithics in Action. Papers from the Conference Lithic Studies in the Year 2000 (2004)

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See detailExperimental comparison of cavity sealing ability of five dental adhesive systems after thermocycling
Cao, L.; Geerts, Sabine ULg; Gueders, Audrey ULg et al

in Journal of Adhesive Dentistry (2003), 5(2, Summer), 139-144

Purpose: To evaluate the cavity sealing obtained after thermocycling with five adhesive systems in which one all-in-one adhesive was compared to three one-bottle adhesives, and to observe the effect of a ... [more ▼]

Purpose: To evaluate the cavity sealing obtained after thermocycling with five adhesive systems in which one all-in-one adhesive was compared to three one-bottle adhesives, and to observe the effect of a low-charged resin layer added to a one-bottle adhesive. Materials and Methods: Twenty-five recently extracted teeth were randomly allocated to five experimental adhesive systems (n = 5 each): Optibond Solo (OS), Scotchbond 1 (SB1), PQ 1, Prompt-L-Pop (PLP), SB1+Revolution (R). On each tooth, two rectangular cavities at the cementoenamel junction were filled with a microhybrid composite (Z100) and the tested adhesives. Teeth were thermocycled and stained with AgNO3 + vitamin C. Leakage was evaluated on a 6-point (0-5) severity scale and the highest score was selected for each restoration. Results were treated by ordinal logistic regression and considered to be significant at p < 0.05. Results: No significant difference was found between leakage values for enamel and dentin interfaces. Leakage scores never exceeded 2 for OS, SB1 and SB1+R, while they reached a maximum of 5 in 20% of PLP cases. OS was significantly better than the other adhesive systems, which were statistically equivalent. The addition of a flowable composite layer on SB1 did not yield a significant difference, but tended to give better results mainly at the dentin interface. Conclusion: The all-in-one adhesive PLP because of quite variable results, seems less reliable than the one-bottle adhesives, of which OS provides significantly the best results. Addition of a flowable composite on SB1 appears to yield slightly better results. [less ▲]

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See detailExperimental cross transmission of Bovine Leukemia Virus (BLV) between several animal species.
Mammerickx, Marc; Portetelle, Daniel ULg; Burny, Arsène

in Zentralblatt für Veterinarmedizin. Reihe B = Journal of Veterinary Medicine. Series B (1981), 28

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