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See detailSimulation based energy consumption calculation of an office building using solar-assisted air conditioning
Thomas, Sébastien ULg; Andre, Philippe ULg

Poster (2008, October)

To minimize environmental impact and CO2 production associated with air-conditioning system operation, it is reasonable to evaluate the prospects of a clean energy source. The targets of the study are to ... [more ▼]

To minimize environmental impact and CO2 production associated with air-conditioning system operation, it is reasonable to evaluate the prospects of a clean energy source. The targets of the study are to evaluate cooling energy consumption to maintain thermal comfort in an office building and to point out solar energy to satisfy these cooling needs. Simulations were carried out with three different cooling systems in the same operating conditions to determine as accurately as possible the potential use of solar energy. For comparison purpose, the base case is a classical air-conditioning system (heat pump for cooling, gas boiler for heating). Two other configurations were simulated: a classical vapour compression system fed by photovoltaic panels and electricity grid as back-up and, absorption chiller fed by solar thermal panel field and by gas boiler. In the three chosen locations (Paris, Lisbon and Stockholm), results shown that installing photovoltaic panels on the roof is really interesting from the primary energy consumption point of view. [less ▲]

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See detailQuand le rein fait défaut. Une journée d’étude consacrée à une maladie chronique.
Rocha, Cindy; Etienne, Anne-Marie ULg

Article for general public (2008)

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See detailDieu a-t-il une passion démesurée pour les insectes?
Haubruge, Eric ULg

Scientific conference (2008, October)

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See detailLinking errors in trend estimation for international surveys in education
Monseur, Christian ULg; Sibberns, H.; Hastedt, D.

in IERI (2008), 1

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See detailTesting the forward modeling approach in asteroseismology. II. Structure and internal dynamics of the hot B subdwarf component in the close eclipsing binary system PG 1336-018
Charpinet, Stéphane; Van Grootel, Valérie ULg; Reese, Daniel et al

in Astronomy and Astrophysics (2008), 489

Aims: We present a stringent test on the forward modeling technique in asteroseismology by confronting the predictions of a detailed seismic analysis of the pulsating subdwarf component in the unique ... [more ▼]

Aims: We present a stringent test on the forward modeling technique in asteroseismology by confronting the predictions of a detailed seismic analysis of the pulsating subdwarf component in the unique close eclipsing binary system PG 1336-018 with those derived independently from modeling the binary light curve of the system. We also take advantage of the observed rotationally-split rich period spectrum to investigate the internal dynamics of the pulsating component in this system expected to be tidally locked. Methods: We carry out numerical exercises based on the double optimization technique that we developed within the framework of the forward modeling approach in asteroseismology. We use a recently updated version that now incorporates the effects of stellar rotation on the pulsation properties. We thus search in parameter space for the optimal model that objectively leads to the best simultaneous match of the 25 periods (including rotationally-split components) observed in PG 1336-018. For the first time, we also attempt to precisely reconstruct the internal rotation profile of the pulsator from its oscillations. Results: Our principal result is that our seismic model, which closely reproduces the observed periods, is remarkably consistent with one of the best-fitting possible solutions uncovered independently from the binary light curve analysis, in effect pointing to the correct one. The latter indicates a mass of Mast = 0.466±0.006 Msun and a radius of Rast = 0.15±0.01 Rsun for the sdB star. In comparison, our seismic analysis, combined to high-quality time-averaged spectroscopy, leads to the following estimates of the basic structural parameters of the sdB component: Mast = 0.459±0.005 Msun, Rast = 0.151±0.001 Rsun, log g = 5.739±0.002, Teff = 32 740 ± 400 K, and log(Menv/Mast) = -4.54±0.07. We also find strong evidence that the sdB star has reached spin-orbit synchronism and rotates as a solid body down to at least r ~ 0.55 Rast. We further estimate that higher-order perturbation effects due to rotation and tidal deformation of the star are insufficient to alter in a significant way the proposed asteroseismic solution itself (i.e., the derived structural parameters and rotation properties). Future efforts to improve further the accuracy of the seismic models will clearly have to incorporate such effects, however. Conclusions: We conclude that our approach to the asteroseismology of sdB stars has passed a fundamental test with this analysis of PG 1336-018. The structural parameters and inferences about the internal dynamics of this star derived in the present paper through this approach should rest on very solid grounds. More generally, our results underline the power and usefulness of the forward modeling method in asteroseismology, despite historical misgivings about it. [less ▲]

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See detailEffects of persistent organic pollutants on the thyroid function of the European sea bass (Dicentrarchus labrax) from the Aegean Sea, is it an endocrine disruption?
Schnitzler, Joseph ULg; Koutrarkis, Emmanuil; Siebert, Ursula et al

in Marine Pollution Bulletin (2008), 56(10), 1755-1764

We evaluated the alterations of organochlorinated compounds such as polychlorobiphenyls (PCB), dichloro-diphenyl-dichloroethylene (DDE) and dichloro-diphenyl-trichloroethane (DDT) on the thyroid in wild ... [more ▼]

We evaluated the alterations of organochlorinated compounds such as polychlorobiphenyls (PCB), dichloro-diphenyl-dichloroethylene (DDE) and dichloro-diphenyl-trichloroethane (DDT) on the thyroid in wild and cultured sea bass (Dicentrarchus labrax) at environmental concentrations. These compounds influence the endocrine system of many fish species and are qualified as endocrine disruptors. The thyroid seems to be a target organ. Two alteration endpoints: the thyroid histology and the muscular thyroid hormone concentrations, were used simultaneously. High concentrations in PCBs and DDT were detected in muscles, supporting the idea that the Mediterranean fauna could be more polluted than the Atlantic fauna. The high abundance of DDE indicates a progressive degradation of remnant DDT load and the absence of new inputs in this area. Aquaculture sea bass shows a significant higher amount of pollutants on fresh weight basis (especially PCBs) in their muscles compared to the wild sea bass. Those differences may be related mainly to the contaminations of diet. Thyroid parameters vary between wild and aquaculture sea bass, wild sea bass were characterized by higher follicle diameters, epithelial cell heights and muscular T4 concentrations. A significant relationship between persistent organic pollutants (muscular PCBs and DDT concentration) and the different thyroid parameters (diameters of follicles, epithelial cell heights and muscular T4 levels) could be observed, which support the hypothesis that these compounds have an adverse impact on thyroid morphometry and function. [less ▲]

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See detailHarbour porpoise thyroids: Histological investigations and potential interactions with environmental factors
Schnitzler, Joseph ULg; Siebert, Ursula; Jepson, Paul et al

in Journal of Wildlife Diseases (2008), 44

The thyroid plays an important role in development and is of primary importance in metabolism and heat loss for cetaceans, including the harbor porpoise (Phocoena phocoena). Several studies have ... [more ▼]

The thyroid plays an important role in development and is of primary importance in metabolism and heat loss for cetaceans, including the harbor porpoise (Phocoena phocoena). Several studies have demonstrated that environmental contaminants can alter various aspects of thyroid function in mammals and may contribute to various histologic changes. The present study completes the data set of a 2006 study by Das et al., by performing histological and immunohistologic investigations on thyroids of 36 harbor porpoises from Belgian and United Kingdom waters. The number and mean diameter of follicles (µm) and the relative proportion of follicular, connective, and vascular tissue (%) were quantified in the thyroid gland of each individual. Interfollicular fibrosis has been observed in these thyroid glands, and the collective findings support the hypothesis of an endocrine disruption of thyroid function through organochlorinated compounds. Our study aimed also to reveal potential relationships between thyroid morphometric data and metal levels (Cd, Fe, Zn, Cu, Se, and Hg) using multivariate statistical analysis. The multiple regressions revealed statistically significant relationships between trace elements (cadmium, selenium, and copper) and thyroid fibrosis. The largely negative relationships are interesting findings but do not support the hypothesis that these elements have an adverse effect on thyroid morphometry. Further research is needed to understand the nature of any relationship between organochlorine and trace element exposure and thyroid gland morphology and function in harbor porpoises. [less ▲]

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See detailReconstruction of Missing Satellite Total Suspended Matter Data over the Southern North Sea and English Channel using Empirical Orthogonal Function Decomposition of Satellite Imagery and Hydrodynamical Modelling
Sirjacobs, Damien ULg; Alvera Azcarate, Aïda ULg; Barth, Alexander ULg et al

Poster (2008, October)

Optical remote sensing data archives generally have many gaps caused by clouds or other retrieval problems. However, for the light forcing of ecosystem models continuous fields are required. For ... [more ▼]

Optical remote sensing data archives generally have many gaps caused by clouds or other retrieval problems. However, for the light forcing of ecosystem models continuous fields are required. For parameters exhibiting strong spatial and temporal correlations for regions of similar dynamics or from day to day, the missing data can be estimated by use of statistical techniques. In this context, the Data Interpolation with Empirical Orthogonal Functions (DINEOF) method is used for reconstruction of complete space-time information for surface total suspended matter (TSM) and chlorophyll a from a 5-year archive of MODIS and MERIS products over the Southern North Sea and English Channel. The DINEOF univariate methodology has been previously demonstrated for Mediterranean sea surface temperature data (Alvera-Azcarate et al., 2005, Beckers et al., 2006). Alvera-Azcarate et al (2007) showed that SST reconstructions could be improved by using a multivariate approach in which SST, chlorophyll and wind fields were taken into account together for the analyses. Here, TSM images will be used in combination with information from the COHERENS hydrodynamical model to provide a complete and continuous estimate of surface TSM for the Southern North Sea throughout the period 2003-2005. In addition to the remotely sensed TSM, the DINEOF multivariate analysis will consider wind fields, depth integrated currents, surface elevations and bottom stresses. Reconstucted images are compared with the original incomplete images. Validation of the method is achieved by estimation of information removed from the training data by exclusion of entire images and by addition of artificial clouds. The data reconstruction technique has further applications in the processing and quality control of optical remote sensing data. Perspectives will be outlined for improving the quality control of retrieved parameters and for the improvement of retrievals by adding statistical information to the conventional spectral processing. References: Alvera-Azcarate, A., Barth, A., Rixen, M., and Beckers, J.-M.: Reconstruction of incomplete oceanographic data sets using Empirical Orthogonal Functions. Application to the Adriatic Sea, Ocean Modelling, 9, 325–346, 2005. Alvera-Azcarate, A., Barth, A., Beckers, J. M., and Weisberg, R. H.: Multivariate Reconstruction of Missing Data in Sea Surface Temperature, Chlorophyll and Wind Satellite Fields, Journal of Geophysical Research, 112, C03008, doi:10.1029/2006JC003660, 2007. Beckers J.-M., A. Barth & A. Alvera-Azcarate, DINEOF reconstruction of clouded images including error maps. Application to the Sea-Surface Temperature around Corsican Island, Ocean Sciences, 2: 183–199, 2006. [less ▲]

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See detailTesting methods applicable to refrigeration components and systems
Quoilin, Sylvain ULg

Poster (2008, October)

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See detailModeling and experimental investigation of an Organic Rankine Cycle using scroll expander for small scale solar applications
Quoilin, Sylvain ULg; Orosz, Matthew; Lemort, Vincent ULg

(2008, October)

This study aims at developing and optimizing an Organic Rankine Cycle (ORC) for a small scale, decentralized parabolic trough system. A numerical model the Organic Rankine Cycle is developed and an ... [more ▼]

This study aims at developing and optimizing an Organic Rankine Cycle (ORC) for a small scale, decentralized parabolic trough system. A numerical model the Organic Rankine Cycle is developed and an experimental study is carried out on an ORC prototype working with refrigerant HCFC-123, and whose heat sources consist in two hot air flows. The ORC model is built by connecting different sub-models: the heat exchanger models, a volumetric pump model and a scroll expander model. Measured performances of the ORC prototype are presented and allow the validation of the ORC model. [less ▲]

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See detailPEO coated magnetic nanoparticles for biomedical application
Aqil, Abdelhafid ULg; Vasseur, S.; Duguet, E. et al

in European Polymer Journal (2008), 44(10), 3191-3199

This paper reports on the preparation, characterization and stealthiness of superparamagnetic nanoparticles (magnetite Fe3O4) with a 5 nm diameter and stabilized in water (pH 6.5) by a shell of water ... [more ▼]

This paper reports on the preparation, characterization and stealthiness of superparamagnetic nanoparticles (magnetite Fe3O4) with a 5 nm diameter and stabilized in water (pH 6.5) by a shell of water-soluble poly(ethylene oxide) (PEO) chains. Two types of diblock copolymers, i.e., poly(acrylic acid)-b-poly(ethylene oxide), PAA–PEO, and poly(acrylic acid)-b-poly(acrylate methoxy poly(ethyleneoxide)), PAA–PAMPEO, were prepared as stabilizers with different compositions and molecular weights. At pH 6.5, the negatively ionized PAA block interacts strongly with the positively-charged nanoparticles, thus playing the role of an anchoring block. Aggregates of coated nanoparticles were actually observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The hydrodynamic diameter was in the 50–100 nm range and the aggregation number (number of nanoparticles per aggregate) was lying between several tens and hundred. Moreover, the stealthiness of these aggregates was assessed “in vitro” by the hemolytic CH50 test. No response of the complement system was observed, such that biomedical applications can be envisioned for these magnetic nanoparticles. Preliminary experiments of magnetic heating (10 kA/m; 108 kHz) were performed and specific absorption rate varied from 2 to 13 W/g(Fe). [less ▲]

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See detailUne lecture scientométrique de la littérature sur les réseaux sociaux en sciences de gestion et en entrepreneuriat
Froehlicher, Thomas ULg; Bares, Franck; Bourgne, Patrick

Conference (2008, October)

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See detailLa répression de la négation du génocide arménien en Belgique : enjeux pluriels pour une absence de décision
Grandjean, Geoffrey ULg

Article for general public (2008)

This article tries to explain the discussions which occured in Belgium in 2006 and 2007 concerning the punishment of armenian genocide-denial.

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See detailLa mort en partage. A propos du Tombeau de Théophile Gautier
Durand, Pascal ULg

in Histoires littéraires (2008), 36

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See detailDéfauts d'orientation et de battement
Debongnie, Jean-François ULg

Report (2008)

The problem of orientation or runout errors being formulated, it is firt noted that these errors necessarily include the form errors of the measured part. The second problem is the correct asseement of a ... [more ▼]

The problem of orientation or runout errors being formulated, it is firt noted that these errors necessarily include the form errors of the measured part. The second problem is the correct asseement of a simulated reference when the reference surface is of imperfect form. The logical choice would be perfect form having the least maximal distance to the physical one. But this choice being a difficult one, the best approximation in the least square sense if often chosed. The effect of this reference perturbation is studied. [less ▲]

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See detailNew simulation tools usable in the energy audit of HVAC systems
Lebrun, Jean ULg; Bertagnolio, Stéphane ULg

Scientific conference (2008, October)

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See detailIntrasaccular injection of aminoglycosides: a novel method for temporary damaging fish inner ear hair cells
Faucher, Karine ULg; Aas-Hansen, Øyvind; Damsgard, Borge et al

Poster (2008, October)

Fish models are increasingly being used for hearing research investigations. Aminoglycoside antibiotics that are used for damaging the inner ear hair cells can have systemic side effects leading to death ... [more ▼]

Fish models are increasingly being used for hearing research investigations. Aminoglycoside antibiotics that are used for damaging the inner ear hair cells can have systemic side effects leading to death of study animals. This study aimed to compare two methods: i) systemic (intravenous) and ii) local (intrasaccular) gentamicin administration for induction of inner ear hair cell damage in the Atlantic cod, Gadus morhua (L.). Hair cell damage was assessed using scanning electron microscopy; hair cell density, prevalence of immature hair cells and kinocilia length were measured. Gentamicin-treated fish were compared with control and sham fish. Intravenous gentamicin led to dose-dependent mortality caused by nephrotoxicity. The only visible effect after treatment was more immature hair cells and shorter kinocilia, the effect on hair cell density was equivocal. Following intrasaccular gentamicin treatment, fish mortality was negligible, and hair cells were damaged regardless of dose. Here, we observed decreased hair cell density, high prevalence of immature hair cells, and significantly shortened kinocilia. Conclusion: intrasaccular injection is preferable to intravenous injection of gentamicin for the study of ototoxicity in the Atlantic cod. [less ▲]

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