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See detailExperimental identification of a non-linear beam, proper othogonal decomposition
Lenaerts, Vincent; Kerschen, Gaëtan ULg; Golinval, Jean-Claude ULg

in International Conference on Structural Systems Identification, Kassel, 2001 (2001)

The aim of the paper is twofold

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See detailExperimental identification of a nonlinear space structure
Noël, Jean-Philippe ULg; Renson, Ludovic ULg; Kerschen, Gaëtan ULg et al

in Proceedings of the 12th European Conference on Spacecraft Structures, Materials and Environmental Testing (2012, March)

The present paper addresses the experimental identification of a nonlinear space structure, the SmallSat spacecraft developed by EADS-Astrium. The nonlinear component comprises an inertia wheel mounted on ... [more ▼]

The present paper addresses the experimental identification of a nonlinear space structure, the SmallSat spacecraft developed by EADS-Astrium. The nonlinear component comprises an inertia wheel mounted on a support, the motion of which is constrained by eight elastomer plots and mechanical stops. Robust techniques are applied to measured data to detect, characterise and quantify nonlinear behaviour. [less ▲]

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See detailExperimental identification of the complex dynamics of a strongly nonlinear spacecraft structure
Noël, Jean-Philippe ULg; Renson, Ludovic ULg; Kerschen, Gaëtan ULg

in Proceedings of the ASME IDETC/CIE 2013 (2013, August)

The present paper addresses the identification of a real-life spacecraft structure possessing an impact-type nonlinear component. The complete identification procedure, i.e. from nonlinearity detection to ... [more ▼]

The present paper addresses the identification of a real-life spacecraft structure possessing an impact-type nonlinear component. The complete identification procedure, i.e. from nonlinearity detection to parameter estimation, is carried out using experimental data collected during a typical spacecraft qualification test campaign. The complementary use of several techniques reveals particularly interesting and complex phenomena such as nonlinear jumps, nonlinear modal interactions, internal force relaxation and chattering during impacts. [less ▲]

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See detailExperimental in situ exposure of the seagrass Posidonia oceanica (L.) Delile to 15 trace elements
Richir, Jonathan ULg; Luy, Nicolas; Lepoint, Gilles ULg et al

in Aquatic Toxicology (2013), 140-141

The Mediterranean seagrass Posidonia oceanica (L.) Delile has been used for trace element (TE) biomonitoring since decades ago. However, present informations for this bioindicator are limited mainly to ... [more ▼]

The Mediterranean seagrass Posidonia oceanica (L.) Delile has been used for trace element (TE) biomonitoring since decades ago. However, present informations for this bioindicator are limited mainly to plant TE levels, while virtually nothing is known about their fluxes through P. oceanica meadows. We therefore contaminated seagrass bed portions in situ at two experimental TE levels with a mix of 15 TEs (Al, V,Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Ag, Cd, Pb and Bi) to study their uptake and loss kinetics in P. oceanica. Shoots immediately accumulated pollutants from the beginning of exposures. Once contaminations ended, TE concentrations came back to their original levels within two weeks, or at least showed a clear decrease. P. oceanica leaves exhibited different uptake kinetics depending on elements and leaf age: the younger growing leaves forming new tissues incorporated TEs more rapidly than the older senescent leaves. Leaf epiphytes also exhibited a net uptake of most TEs, partly similar to that of P. oceanica shoots. The principal route of TE uptake was through the water column, as no contamination of superficial sediments was observed. However, rhizomes indirectly accumulated many TEs during the overall experiments through leaf to rhizome translocation processes. This study thus experimentally confirmed that P.oceanica shoots are undoubtedly an excellent short-term bioindicator and that long-term accumulations could be recorded in P. oceanica rhizomes. [less ▲]

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See detailExperimental in vivo infection of pigs by a Belgian wild boar hepatitis E virus strain
Thiry, Damien ULg; Rose, Nicolas; Paboeuf, Frédéric et al

Poster (2014, October)

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See detailExperimental in vivo infection of pigs by a wild boar hepatitis E virus strain
Thiry, Damien ULg; Rose, Nicolas; Paboeuf, Frédéric et al

Conference (2014, October 17)

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See detailExperimental induction of prenucleolar bodies (PNBs) in interphase cells: interphase PNBs show similar characteristics as those typically observed at telophase of mitosis in untreated cells.
Zatsepina, O. V.; Dudnic, O. A.; Todorov, I. T. et al

in Chromosoma (1997), 105(7-8), 418-30

Recently, it was shown that a short exposure of living mammalian cells to low ionic strength buffers (hypotonic shock) caused partial or almost complete unraveling of interphase nucleoli. However, when ... [more ▼]

Recently, it was shown that a short exposure of living mammalian cells to low ionic strength buffers (hypotonic shock) caused partial or almost complete unraveling of interphase nucleoli. However, when the cells were released from the hypotonic shock and transferred to normal isotonic medium, functionally active and structurally integral nucleoli were reassembled at their initial positions within interphase nuclei. Here, we show further that this process is accompanied by the appearance of numerous discrete extranucleolar bodies, which have striking similarities to the prenucleolar bodies (PNBs) observed in untreated cells at telophase of mitosis. (1) Like PNBs at mitosis, hypotonically induced interphase PNBs are composed of RNA-positive granules and fibrils, contain the major nucleolar protein B23 and silver-binding proteins, but lack DNA and RNA polymerase I transcription factor UBF. (2) As for mitotic PNBs, disappearance of the interphase PNB counterparts coincides with the increase in size of reconstructed nucleoli. (3) Addition of actinomycin D does not prevent assembly of interphase PNBs, but does arrest their coalescence with the chromosomal nucleolus-organizing regions and blocks the complete reformation of nucleoli. It is concluded that the assembly of PNBs generally observed at telophase of mitosis can be induced experimentally in nuclei of interphase mammalian cells in vivo. At interphase, this process is probably initiated by changes in the intracellular ionic environment. [less ▲]

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See detailExperimental Infection of Bulls with a Genital Isolate of Bovine Herpesvirus-4 and Reactivation of Latent Virus with Dexamethasone
Dubuisson, J.; Thiry, Etienne ULg; Bublot, M. et al

in Veterinary Microbiology (1989), 21(2), 97-114

Five 13- to 18-month old Belgian Blue bulls were used in this experiment. Four bulls (Nos. 2, 3, 4 and 5) were inoculated intratesticularly with 10(5) plaque-forming units of bovine herpesvirus-4 (BHV-4 ... [more ▼]

Five 13- to 18-month old Belgian Blue bulls were used in this experiment. Four bulls (Nos. 2, 3, 4 and 5) were inoculated intratesticularly with 10(5) plaque-forming units of bovine herpesvirus-4 (BHV-4) in each testicle (Day 0). The challenge BHV-4 strain was previously isolated from testicle cells of a bull exhibiting orchitis and azoospermia. The fifth bull (No. 1) was used as a control and received the same volume of uninfected cell culture supernatant. For 5 days, beginning on Day 51 post-infection, two bulls (Nos. 4 and 5) and the control bull (No. 1) received 0.1 mg kg-1 of dexamethasone. Unilateral castrations were then performed at regular intervals for viral examination. Treatment with dexamethasone reactivated latent BHV-4, but no clinical signs were observed in treated bulls until the end of the experiment (Day 93). Only Bull 3 showed conjunctivitis and temporary azoospermia. The virus was recovered from various samples showing that: (i) BHV-4 can be present in a latent state in the testicles and mononuclear blood cells; (ii) dexamethasone reactivates the virus; (iii) the virus is excreted by nasal and ocular routes. Each infected bull seroconverted and a booster antibody response appeared after dexamethasone treatment as shown by immunofluorescence. Neutralizing antibodies were detected in each bull by complement-dependent neutralization test with titres higher than those obtained by a classical neutralization test. No booster response of neutralizing antibodies was observed after dexamethasone treatment. The antigenically relevant envelope BHV-4 proteins were identified by Western blotting using sera samples from the animals. DNA restriction endonuclease profiles of viruses reisolated after primary infection and reactivation showed only small differences. [less ▲]

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See detailExperimental infection of reindeer with cervid herpesvirus 2
das Neves, C.; Mork, T.; Godfroid, J. et al

in Clinical and Vaccine Immunology (2009), 16

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See detailExperimental Infection of Specific Pathogen-Free New Zealand White Rabbits with Five Strains of Amyxomatous Myxoma Virus
Marlier, Didier ULg; Cassart, Dominique ULg; Boucraut-Baralon, C. et al

in Journal of Comparative Pathology (1999), 121(4), 369-84

Myxomatosis is a specific disease of the European rabbit (Oryctolagus cuniculus) due to a virus belonging to the genus Leporipoxvirus. Forty-seven years after its deliberate introduction into Europe, the ... [more ▼]

Myxomatosis is a specific disease of the European rabbit (Oryctolagus cuniculus) due to a virus belonging to the genus Leporipoxvirus. Forty-seven years after its deliberate introduction into Europe, the clinical aspects and the epizootiology of myxomatosis have changed. Two forms (nodular and amyxomatous) of the disease have been identified to date. A comparative study was made of the clinical signs, pathogenesis and gross lesions observed in male specific pathogen-free New Zealand White rabbits inoculated with five strains of amyxomatous myxoma virus. All five strains induced the characteristic amyxomatous myxomatosis clinical syndrome with clinical signs that differed only in intensity. The varying clinical intensity, together with the results of virological examination question the virulence of at least three of the five strains. Genomic analysis confirmed that the five strains came from the Lausanne strain introduced in 1952 in France and not from an unnoticed introduction of a Californian strain of myxoma virus. No link was found between the amyxomatous myxoma virus strains and the SG33 vaccine strain. 1999 Harcourt Publishers Ltd. [less ▲]

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See detailExperimental investigation and phenomenological modeling of the quasi-static mechanical behavior of TA6V titanium alloy
Gilles, Gaëtan ULg; Habraken, Anne ULg; Duchene, Laurent ULg

in Key Engineering Materials [=KEM] (2014), 622-623

This paper proposes an experimental and numerical investigation of the quasi-static mechanical behavior of TA6V at room temperature. Different loading conditions ( tension, compression, plane strain ans ... [more ▼]

This paper proposes an experimental and numerical investigation of the quasi-static mechanical behavior of TA6V at room temperature. Different loading conditions ( tension, compression, plane strain ans simple shear) were applied on a 0.6 mm thick sheet in several in plane directions. Based on the experimental results, several identifications are performed to determinate the parameters involved in the CPB06 yield criterion and its extensions. The error/time computation ratio for the different identifications is next analysed to fix the choice of the yield criterion. The latter is finally associated with an isotropic hardening law on the one side and a formulation taking into account the evolution of the yield locus on the other side in order to describe the material. The ability of the proposed formulations to predict the TA6V response is studied int he case of a deep-drawing process. [less ▲]

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See detailExperimental investigation of an ORC system for a micro-solar power plant
Dickes, Rémi ULg; Dumont, Olivier ULg; Declaye, Sébastien ULg et al

Conference (2014)

Because of the depletion of fossil fuels and global warming issues, the world energy sector is undergoing various changes towards increased sustainability. Among the different technologies being developed ... [more ▼]

Because of the depletion of fossil fuels and global warming issues, the world energy sector is undergoing various changes towards increased sustainability. Among the different technologies being developed, solar energy, and more specifically CSP (Concentrated Solar Power) systems are expected to play a key role to supply centralized loads and off-grid areas in the medium-term. Major performance improvements can be achieved by implementing advanced control strategies accounting for the transient and random nature of the solar heat source. In this context, a lab-scale solar power plant has been designed and is under construction for experimental purposes and dynamic analysis. The test rig includes an Organic Rankine Cycle (ORC) unit, a field of parabolic trough collectors and a thermal energy storage system. This paper presents the results of an experimental campaign conducted on the ORC module alone. This power unit, designed for a 2.8 kW net electrical output, consists of two scroll expanders in series, an air-cooled condenser, a recuperator, a volumetric pump and an oil-heated evaporator. The ORC engine is constructed using standard mass manufactured components from the HVAC industry, this practice reducing considerably the system cost. The overall unit performance and components effectiveness are presented in different operating conditions and relevant empirical correlations are derived to be implemented in a steady state model of the ORC unit. [less ▲]

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See detailExperimental investigation of droplet biosensing by multi-wavelength plasmonic
Desfours, Caroline ULg; Habraken, Serge ULg; Hastanin, Juriy ULg et al

in Proceedings of SPIE Vol. 8234 : Plasmonics in Biology and Medicine IX (2012)

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See detailExperimental investigation of flow and deposit patterns in rectangular shallow reservoirs: preliminary analysis
Dufresne, Matthieu ULg; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in Proceedings International Workshop on Environmental Hydraulics: Theoretical, Experimental and Computational Solutions (2009)

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See detailExperimental investigation of flow pattern and sediment deposition in rectangular shallow reservoirs
Dufresne, Matthieu; Dewals, Benjamin ULg; Erpicum, Sébastien ULg et al

in International Journal of Sediment Research (2010), 25(3), 258-270

This work involved the experimental investigation of flow pattern, preferential regions of deposition and trap efficiency as a function of the length of rectangular shallow reservoirs. Four flow patterns ... [more ▼]

This work involved the experimental investigation of flow pattern, preferential regions of deposition and trap efficiency as a function of the length of rectangular shallow reservoirs. Four flow patterns were identified (from longer to shorter reservoirs): an asymmetric flow with two reattachment points, an asymmetric flow with one reattachment point, an unstable flow, and a symmetric flow without any reattachment point. Using dye visualizations, the median value and the temporal variability of the reattachment lengths were precisely measured for the asymmetric flows. For each stable flow, sediment tests with plastic particles were carried out. The regions of deposition on the bed of the reservoir were clearly a function of the flow pattern. The transition from an asymmetric flow pattern to a symmetric flow pattern was responsible for an abrupt decrease of the trap efficiency; a number of regression laws were discussed to take it into account. [less ▲]

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See detailExperimental investigation of meandering jets in shallow reservoirs
Peltier, Yann ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in Environmental Fluid Mechanics (2014)

Meandering flows in rectangular shallow reservoirs were experimentally investi- gated. The characteristic frequency, the longitudinal wave length and the mean lateral exten- sion of the meandering jet ... [more ▼]

Meandering flows in rectangular shallow reservoirs were experimentally investi- gated. The characteristic frequency, the longitudinal wave length and the mean lateral exten- sion of the meandering jet were extracted from the first paired modes, obtained by a proper orthogonal decomposition of the surface velocity field measured by large scale PIV. The depth-normalised characteristic lengths and the Strouhal number were then compared to the main dimensionless numbers characterizing the experiments: Froude number, friction num- ber and reservoir shape factor. The normalised wave length and mean lateral extension of the meandering jet are neither correlated with the Froude number nor with the reservoir shape factor; but a clear relationship is found with the friction number. Similarly, the Strouhal num- ber is found proportional to a negative power of the friction number. In contrast, the Froude number and the reservoir shape factor enable to predict the occurrence of a meandering flow pattern: meandering jets occur for Froude number greater than 0.21 and for a shape factor smaller than 6.2. [less ▲]

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See detailEXPERIMENTAL INVESTIGATION OF NOx FORMATION MECHANISMS IN A FUEL-OIL BOILER
Tartari, Paula; Ngendakumana, Philippe ULg

Conference (2002, June)

The work whose results are reported in this paper was aimed at gathering information that can give a deeper insight into the structure of a diffusion fuel-oil flame. This allows us to get a better ... [more ▼]

The work whose results are reported in this paper was aimed at gathering information that can give a deeper insight into the structure of a diffusion fuel-oil flame. This allows us to get a better understanding of the combustion process and thus a correct basis for combustion modeling, focused on NOx formation. In order to attain the objective, axial and radial temperature, NOx and O2 concentration profiles have been measured in the flame for high and low firing rates of a domestic hot water boiler (around 424 and 270 kW respectively). Temperature was measured by means of two B-type thermocouples (diameters 0.5 and 0.35 mm) and NOx and O2 concentrations using a classical gas analyzer. Maximum NOx emissions (167 ppm at 424 kW and 134 ppm at 270 kW) were recorded in high oxygen concentration and low temperature zones of the flame ( ≈ 1000°C), where no thermal-NO can be formed. Flue gas recirculation and NOx destruction process is clearly demonstrated in the flame due to the higher NOx concentrations recorded in the combustion chamber near the burner exit than in the chimney. Near the burner exit NOx, O2 and temperature radial profiles are very unstable. Higher temperature fluctuations were detected with the small thermocouple in the measurements at 270 kW. The contribution of the three types of NOx formation mechanisms was obtained using a simplified model. According to these results, the majority of NOx in this type of flame could be caused by the prompt-NO mechanism, formed in the zone close to the burner exit at the location where secondary combustion air is introduced. [less ▲]

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