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See detailA coupled electro-thermal Discontinuous Galerkin method
Homsi, Lina ULg; Geuzaine, Christophe ULg; Noels, Ludovic ULg

in Journal of Computational Physics (in press)

This paper presents a Discontinuous Galerkin scheme in order to solve the nonlinear elliptic partial differential equations of coupled electro-thermal problems. In this paper we discuss the fundamental ... [more ▼]

This paper presents a Discontinuous Galerkin scheme in order to solve the nonlinear elliptic partial differential equations of coupled electro-thermal problems. In this paper we discuss the fundamental equations for the transport of electricity and heat, in terms of macroscopic variables such as temperature and electric potential. A fully coupled nonlinear weak formulation for electro-thermal problems is developed based on continuum mechanics equations expressed in terms of energetically conjugated pair of fluxes and fields gradients. The weak form can thus be formulated as a Discontinuous Galerkin method. The existence and uniqueness of the weak form solution are proved. The numerical properties of the nonlinear elliptic problems i.e., consistency and stability, are demonstrated under specific conditions, i.e. use of high enough stabilization parameter and at least quadratic polynomial approximations. Moreover the prior error estimates in the H1-norm and in the L2-norm are shown to be optimal in the mesh size with the polynomial approximation degree. [less ▲]

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See detailEffects of agricultural land use on fluvial carbon dioxide, methane and nitrous oxide concentrations in a large European river, the Meuse (Belgium)
Borges, Alberto ULg; Darchambeau, F.; Lambert, T et al

in Science of the Total Environment (2018), 610–611

We report a data-set of CO2, CH4, and N2O concentrations in the surface waters of the Meuse river network in Belgium, obtained during four surveys covering 50 stations (summer 2013 and late winter 2013 ... [more ▼]

We report a data-set of CO2, CH4, and N2O concentrations in the surface waters of the Meuse river network in Belgium, obtained during four surveys covering 50 stations (summer 2013 and late winter 2013, 2014 and 2015), from yearly cycles in four rivers of variable size and catchment land cover, and from 111 groundwater samples. Surface waters of the Meuse river network were over-saturated in CO2, CH4, N2O with respect to atmospheric equilibrium, acting as sources of these greenhouse gases to the atmosphere, although the dissolved gases also showed marked seasonal and spatial variations. Seasonal variations were related to changes in freshwater discharge following the hydrological cycle, with highest concentrations of CO2, CH4, N2O during low water owing to a longer water residence time and lower currents (i.e. lower gas transfer velocities), both contributing to the accumulation of gases in the water column, combined with higher temperatures favourable to microbial processes. Inter-annual differences of discharge also led to differences in CH4 and N2O that were higher in years with prolonged low water periods. Spatial variations were mostly due to differences in land cover over the catchments, with systems dominated by agriculture (croplands and pastures) having higher CO2, CH4, N2O levels than forested systems. This seemed to be related to higher levels of dissolved and particulate organic matter, as well as dissolved inorganic nitrogen in agriculture dominated systems compared to forested ones. Groundwater had very low CH4 concentrations in the shallow and unconfined aquifers (mostly fractured limestones) of the Meuse basin, hence, should not contribute significantly to the high CH4 levels in surface riverine waters. Owing to high dissolved concentrations, groundwater could potentially transfer important quantities of CO2 and N2O to surface waters of the Meuse basin, although this hypothesis remains to be tested. [less ▲]

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See detailCANINE GANGRENOUS MASTITIS : A CASE REPORT
Egyptien, Sophie ULg; Lefebvre, Michaël ULg; Guieu, Liz-Valéry ULg et al

Poster (2017, July)

This report describes the treatments and discusses the cost effectiveness of a Negative Pressure Wound Therapy (NPWT) device on a gangrenous mastitis case. Mastitis is an inflammation of the mammary gland ... [more ▼]

This report describes the treatments and discusses the cost effectiveness of a Negative Pressure Wound Therapy (NPWT) device on a gangrenous mastitis case. Mastitis is an inflammation of the mammary gland found mainly in lactating females. Coliforms (Escherichia coli), Staphylococcus spp (Staphylococcus aureus) and, to a lesser extent, Streptococcus spp are the most commonly isolated organisms in bitches. The bitch can be presented because of local signs of inflammation, puppies failing to thrive or even severe septic shock. While more common in ruminants, gangrenous mastitis is rare in the bitch. It is mostly due to Staphylococcus aureus, a gram positive and catalase positive bacteria producing alpha hemolysin. This toxin binds to ADAM10, a transmembrane protein, forming pores in the cell membrane, causing an acute inflammation via intracellular calcium flow, leading to severe oedema, necrosis and gangrene. Loss of skin integrity also comes from the cleavage of E-cadherin by ADAM10 after its toxin-mediated activation. A 8.7kg, 3-year-old neutered female Sheltie farm dog was referred to the Veterinary Clinic of the University of Liège for suspicion of septic peritonitis after an ovariohysterectomy on 4 dead puppies 36 hours earlier. They died during long lasting dystocia. Amoxicillin-acid clavulanic and enrofloxacin antibiotherapy had been initiated during surgery. The dog was in decompensated septic shock. The surgical wound was not reactive and no sign of peritonitis was seen by abdominal ultrasonography. The right inguinal and the two most caudal left mammary glands were swollen, crackling with a patchy blue discoloration. An acute fulminant mastitis with gangrenous involvement and sepsis was diagnosed. Fluids and continuous rate infusion of norepinephrine and dobutamine were administered to control severe hypotension. Metronidazole was added since Clostridium spp could not be excluded. Debridement was started as soon as the arterial pressure was stabilised and the wound was disinfected with hydrogen peroxyde for the 3 first days. While hydrogen peroxyde is indicated for catalase negative infections, the already started antibiotherapy prevented bacterial identification and sensitivity determination. Alginate-honey patches replaced wet to dry bandages after 4 days. After 7 days of progressive debridement, the wound was 15cm long, 13cm wide and 1.2cm deep. A NPWT device was placed under anaesthesia after extensive debridement. It was kept in place for one week with one renewal after 2 days under slight sedation. The wound was then surgically closed. Cutaneous sutures were removed 10 days later as cicatrization was satisfactory. NPWT is indicated in open wound management, for infection control and for stimulating granulation tissue production prior to reconstruction. It increases contraction in deep, three dimensional wounds. Closure rate is significantly shorter with NPWT than with standard wet to dry bandages. Cost of NPWT is comparable to standard bandages but more comfortable for the patient. Standards bandages require daily changes, sometimes for several weeks and under repeated anaesthesias, which may be debilitating for the patient and expensive for the owner. Conversely, NPWT is changed only once and allows earlier surgical closure of the wound. The main complication is vacuum loss, which is surgeon’s experience dependant. [less ▲]

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See detailRule-based control and optimization of a hybrid solar microgrid for rural electrification and heat supply in sub-Saharan Africa
Altés Buch, Queralt ULg; Orosz, Matthew; Quoilin, Sylvain ULg et al

in Proceedings of the 30th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS) (2017)

This work aims at developing, optimizing and controlling a hybrid solar microgrid for rural electrification and heat supply in sub-Saharan Africa. The considered system includes PV panels, Parabolic ... [more ▼]

This work aims at developing, optimizing and controlling a hybrid solar microgrid for rural electrification and heat supply in sub-Saharan Africa. The considered system includes PV panels, Parabolic Trough Collectors, ORC and LPG generator, as well as battery and thermal energy storage. A special focus is paid to the co-optimization of the thermal and electrical load satisfaction since it can improve the overall energy efficiency of the system. To that end, different sub-component models are developed: - A building model to predict thermal loads of a health clinic in rural communities of Lesotho. - A microgrid model built by interconnecting the subcomponent models. - A rule-based control strategy, dispatching heat and electrical powers of each component to cover the demand while minimizing the fuel consumption. - A particle-swarm optimization of the microgrid under different cost assumptions. For the studied community of Ha Nkau in Lesotho, the determined optimal system infrastructure is composed of PV (66 kW) and batteries (262 kWh), and the optimum control strategy achieves a levelized cost of electricity of 0.203 USD/kWh. Fuel consumption is mainly due to the burner, which supplies most of the thermal load together with CSP (66 m2) and TES (86 kWh). [less ▲]

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See detailEconomic factors influencing zoonotic disease dynamics: demand for poultry meat and seasonal transmission of avian influenza in Vietnam.
Delabouglise, Alexis; Choisy, Marc; Phan, Thang D. et al

in Scientific Reports (2017), 7(1), 5905

While climate is often presented as a key factor influencing the seasonality of diseases, the importance of anthropogenic factors is less commonly evaluated. Using a combination of methods - wavelet ... [more ▼]

While climate is often presented as a key factor influencing the seasonality of diseases, the importance of anthropogenic factors is less commonly evaluated. Using a combination of methods - wavelet analysis, economic analysis, statistical and disease transmission modelling - we aimed to explore the influence of climatic and economic factors on the seasonality of H5N1 Highly Pathogenic Avian Influenza in the domestic poultry population of Vietnam. We found that while climatic variables are associated with seasonal variation in the incidence of avian influenza outbreaks in the North of the country, this is not the case in the Centre and the South. In contrast, temporal patterns of H5N1 incidence are similar across these 3 regions: periods of high H5N1 incidence coincide with Lunar New Year festival, occurring in January-February, in the 3 climatic regions for 5 out of the 8 study years. Yet, daily poultry meat consumption drastically increases during Lunar New Year festival throughout the country. To meet this rise in demand, poultry production and trade are expected to peak around the festival period, promoting viral spread, which we demonstrated using a stochastic disease transmission model. This study illustrates the way in which economic factors may influence the dynamics of livestock pathogens. [less ▲]

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See detailWhen Belgians Are the Migrants: An Overview of Narratives, Public Policies and Actors Framing the Question of Emigration in Belgium
Mandin, Jérémy ULg

in Weinar, Agnieszka (Ed.) Emigration and Diaspora Policies in the Age of Mobility (2017)

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See detailReliability maps for seismic tomography
Fechner, Thomas; Ehosioke, Solomon ULg; Mackens, Sonja et al

in SEG Global Meeting Abstracts (2015, November 06)

Seismic borehole tomography has become a standard method and is routinely used for the detection of karstic phenomena and the delineation of geological structures. Seismic tomography is believed to be the ... [more ▼]

Seismic borehole tomography has become a standard method and is routinely used for the detection of karstic phenomena and the delineation of geological structures. Seismic tomography is believed to be the seismic method promising the most accuracy and reliability. Remaining uncertainties due to a non-zero residual is often neglected. However, the quality of the photographs is very high. We present tomographic inversion results in the signal-to-noise ratio of the first arrival time. This new data quality weighting scheme is assumed to provide more reliable inversion results. Information about the reliability of the tomogram provided with the geophysicist interpretation. The effect of the data quality weighted inversion is studied on a field data set. [less ▲]

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See detailTaxonomie locale et analyse des critères des paysans pour caractériser les différents écotypes d'oignons (Allium cepa L.) du Niger
Abdou, Rabiou; Malice, Marie; Bakasso, Yacoubou et al

in Cahiers d'Etudes et de Recherches Francophones. Agricultures (2014), 23(3), 166-176

The onion is a very important crop in Niger, which has developed a reputation of high quality for ages. In Niger, many analyses have been carried out concerning onion production, but very little research ... [more ▼]

The onion is a very important crop in Niger, which has developed a reputation of high quality for ages. In Niger, many analyses have been carried out concerning onion production, but very little research has been done on onion ecotypes. The aims of this work were to identify the different types of onion produced in Niger. About a dozen sites were visited in the main area of mass production of onion in Niger. Interviews were conducted with ten producers on each site visited. These producers have a good knowledge of the different types of onions produced in the area and all over the country. Descriptors for Allium, established by Biodiversity International (ex IPGRI), have been used to characterize the onion ecotypes. Fifty two locally named ecotypes were identified, but after analysis and grouping by synonyms, it was found that 17 of them were produced in Niger. The main criteria for a local ectoype naming are the colour of the onion bulb and the production area. [less ▲]

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