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Peer Reviewed
See detailOptimized integration of heat storage into district heating networks fed by a biomass CHP plant.
Sartor, Kevin ULg

in Proceedings (2017, February 28)

Biomass Combined Heat and Power (CHP) plants connected to district heating networks (DHN) are recognized as a very good opportunity to increase the share of renewable sources into energy systems. However ... [more ▼]

Biomass Combined Heat and Power (CHP) plants connected to district heating networks (DHN) are recognized as a very good opportunity to increase the share of renewable sources into energy systems. However, as CHP plants are not optimized for electricity production, their operation is profitable only if a sufficient heat demand is available throughout the year. On the other hand, these plants often work for baseline operation and back-up boilers are used to supply the peak demand. To extend the use of the CHP plants and reduce costs, conventional fuel use and emissions, it is proposed to study the feasibility of using additional high temperature heat storage as retrofit of an existing CHP plant. This work is based on a simple and effective methodology that provides accurate estimations of economic, environmental and energetic performances of CHP plants connected to district heating networks. The DHN of the University in Liège (Belgium) is used as an application framework to demonstrate the effectiveness of the selected approach. The potential energy and pollutant emissions savings and resulting energy costs are estimated and the current policy limitations will be discussed. [less ▲]

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See detailLiens entre mathématiques et jeux
Bair, Jacques ULg

E-print/Working paper (2017)

Le présent travail se compose de plusieurs parties. En premier lieu, nous définissons le concept général de jeu et présentons quelques mathématiciens célèbres, de toutes époques, qui étaient (ou sont ... [more ▼]

Le présent travail se compose de plusieurs parties. En premier lieu, nous définissons le concept général de jeu et présentons quelques mathématiciens célèbres, de toutes époques, qui étaient (ou sont encore) des adeptes de jeux mathématiques. Ensuite, nous établissons une typologie des jeux mathématiques. Une deuxième partie est consacrée à l’intervention des jeux dans l’enseignement des mathématiques. Nous donnons divers avantages des activités ludiques en classe, mais également des objections relatives à leur usage à des fins pédagogiques. Nous nous demandons aussi comment sélectionner un jeu pour des élèves et exhibons des exemples concrets de jeux exploitables en classe. Ce travail se termine par une bibliographie sur le sujet, ainsi que par une annexe composée de diapositives présentées lors d’un exposé réalisé à l’Université du Luxembourg dans le cadre de la Formation Pédagogique (FOPED) : nous y décrivons brièvement différentes épreuves ludiques proposées ces dernières années à des élèves de l’enseignement secondaire en France, Belgique et au Luxembourg. [less ▲]

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See detailRevisiting global fossil fuel and biofuel emissions of ethane
Tzompa-Sosa, Z. A.; Mahieu, Emmanuel ULg; Franco, Bruno ULg et al

in Journal of Geophysical Research. Atmospheres (2017), 122(4), 2493--2512

Recent measurements over the Northern Hemisphere indicate that the long-term decline in the atmospheric burden of ethane (C2H6) has ended and the abundance increased dramatically between 2010 and 2014 ... [more ▼]

Recent measurements over the Northern Hemisphere indicate that the long-term decline in the atmospheric burden of ethane (C2H6) has ended and the abundance increased dramatically between 2010 and 2014. The rise in C2H6 atmospheric abundances has been attributed to oil and natural gas extraction in North America. Existing global C2H6 emission inventories are based on outdated activity maps that do not account for current oil and natural gas exploitation regions. We present an updated global C2H6 emission inventory based on 2010 satellite-derived CH4 fluxes with adjusted C2H6 emissions over the U.S. from the National Emission Inventory (NEI 2011). We contrast our global 2010 C2H6 emission inventory with one developed for 2001. The C2H6 difference between global anthropogenic emissions is subtle (7.9 versus 7.2 Tg yr−1), but the spatial distribution of the emissions is distinct. In the 2010 C2H6 inventory, fossil fuel sources in the Northern Hemisphere represent half of global C2H6 emissions and 95% of global fossil fuel emissions. Over the U.S., unadjusted NEI 2011 C2H6 emissions produce mixing ratios that are 14–50% of those observed by aircraft observations (2008–2014). When the NEI 2011 C2H6 emission totals are scaled by a factor of 1.4, the Goddard Earth Observing System Chem model largely reproduces a regional suite of observations, with the exception of the central U.S., where it continues to underpredict observed mixing ratios in the lower troposphere. We estimate monthly mean contributions of fossil fuel C2H6 emissions to ozone and peroxyacetyl nitrate surface mixing ratios over North America of ~1% and ~8%, respectively. [less ▲]

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See detailCarbon dioxide evasion from the Seine River: Drivers analysis and spatiotemporal reconstruction
Marescaux, A; Thieu, v; Borges, Alberto ULg et al

Conference (2017, February 26)

Detailed reference viewed: 7 (1 ULg)
Peer Reviewed
See detailThermal comfort models for net zero energy buildings in hot climates
Belkhouane, Hamza ULg; Hensen, Jan; Attia, Shady ULg

in Second International Conference on Energy and Indoor Environment for Hot Climates (2017, February 26)

Several energy efficiency concepts and comfort models emerged in the last 15 years seeking high performance buildings and optimal occupant comfort conditions. The aim of high performance buildings is to ... [more ▼]

Several energy efficiency concepts and comfort models emerged in the last 15 years seeking high performance buildings and optimal occupant comfort conditions. The aim of high performance buildings is to reduce the carbon footprint and energy consumption of buildings while maintain a fit to purpose comfort. In this context, this work raises the question of fir to purpose comfort models that can from one side reduce the energy consumption of typical office buildings in hot climates (cooling dominated) while on the other side ensuring indoor thermal comfort. Indeed, studies that address energy efficiency are many, however it is in most cases applied to temperate or cold climates and barely explored for hot climates. The objective of this paper is to (1) combine several comfort models for a net zero energy building in hot climates, (2) select the comfort model that shows the optimal comfort quality of indoor environment and (3) compare the building's annual energy consumption for each used comfort model. To respond to our research problems, a methodology has been established, which goes through several phases. First identifying the different comfort models comfortable to use in hot climates (ISO 7730 / EN 15251 / adaptive ASHRAE / Givoni), secondly selecting a typical validated office building model as a reference building and finally selecting representative cities in the Mediterranean arid and hot climate (Algiers / Sicily / Cairo / Dubai). The study used building performance simulation to generate the different results on the energy consumption and the operative temperatures of the different models of comfort in each city. The paper ultimately identifies the fit to purpose comfort models for a medium size net zero energy office building in hot climates. The paper presents a comparison that can help building professional to identify the most appropriate comfort model that allows optimizing energy consumption, ensuring thermal comfort for robust perfromnce of net zero energy buildings in hot climates. [less ▲]

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See detailI Am Very Sorry Sir! Breaking Bad News to Customers
Delcourt, Cécile ULg; Gremler, Dwayne; Greer, Dominique

Scientific conference (2017, February 25)

Detailed reference viewed: 31 (2 ULg)
See detailGenscript meeting invited by GIGA viral vector platform
Golestan Hashemi, Farahnaz Sadat ULg

Learning material (2017)

Detailed reference viewed: 24 (2 ULg)
Peer Reviewed
See detailMethylglyoxal-induced carbonyl stress: perspectives of a new anti-GBM therapy
Nokin, Marie-Julie ULg

Conference (2017, February 24)

Detailed reference viewed: 21 (1 ULg)
See detailCompréhension et prise en charge de la schizophrénie : Présentation du modèle « 3Id »
Englebert, Jérôme ULg

Scientific conference (2017, February 24)

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See detailLes éventrations parastomales: prévention et traitement
DETRY, Olivier ULg

Scientific conference (2017, February 24)

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See detailInterplay between Penicillin-binding proteins and SEDS proteins promotes bacterial cell wall synthesis.
Leclercq, Sophie ULg; Derouaux, Adeline ULg; Olatunji, Samir ULg et al

in Scientific Reports (2017), 7

Bacteria utilize specialized multi-protein machineries to synthesize the essential peptidoglycan (PG) cell wall during growth and division. The divisome controls septal PG synthesis and separation of ... [more ▼]

Bacteria utilize specialized multi-protein machineries to synthesize the essential peptidoglycan (PG) cell wall during growth and division. The divisome controls septal PG synthesis and separation of daughter cells. In E. coli, the lipid II transporter candidate FtsW is thought to work in concert with the PG synthases penicillin-binding proteins PBP3 and PBP1b. Yet, the exact molecular mechanisms of their function in complexes are largely unknown. We show that FtsW interacts with PBP1b and lipid II and that PBP1b, FtsW and PBP3 co-purify suggesting that they form a trimeric complex. We also show that the large loop between transmembrane helices 7 and 8 of FtsW is important for the interaction with PBP3. Moreover, we found that FtsW, but not the other flippase candidate MurJ, impairs lipid II polymerization and peptide cross-linking activities of PBP1b, and that PBP3 relieves these inhibitory effects. All together the results suggest that FtsW interacts with lipid II preventing its polymerization by PBP1b unless PBP3 is also present, indicating that PBP3 facilitates lipid II release and/or its transfer to PBP1b after transport across the cytoplasmic membrane. This tight regulatory mechanism is consistent with the cell's need to ensure appropriate use of the limited pool of lipid II. [less ▲]

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See detailA class of valid inequalities for multilinear 0-1 optimization problems
Crama, Yves ULg; Rodriguez Heck, Elisabeth ULg

in Discrete Optimization (2017)

This paper investigates the polytope associated with the classical standard linearization technique for the unconstrained optimization of multilinear polynomials in 0-1 variables. A new class of valid ... [more ▼]

This paper investigates the polytope associated with the classical standard linearization technique for the unconstrained optimization of multilinear polynomials in 0-1 variables. A new class of valid inequalities, called 2-links, is introduced to strengthen the LP relaxation of the standard linearization. The addition of the 2-links to the standard linearization inequalities provides a complete description of the convex hull of integer solutions for the case of functions consisting of at most two nonlinear monomials. For the general case, various computational experiments show that the 2- links improve both the standard linearization bound and the computational performance of exact branch & cut methods. The improvements are especially significant for a class of instances inspired from the image restoration problem in computer vision. The magnitude of this effect is rather surprising in that the 2-links are in relatively small number (quadratic in the number of terms of the objective function). [less ▲]

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See detailDialogues sur la Diversité
Brahy, Rachel ULg; Dumont, Elisabeth

Conference given outside the academic context (2017)

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Peer Reviewed
See detailImplementation of the biogenic emission model MEGAN(v2.1) into the ECHAM6-HAMMOZ chemistry climate model
Henrot, Alexandra-Jane ULg; Stanelle, T.; Schröder, S. et al

in Geoscientific Model Development [=GMD] (2017), 10

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Peer Reviewed
See detailSeven temperate terrestrial planets around the nearby ultracool dwarf star
Gillon, Michaël ULg; Triaud, Amaury; Demory, Brice-Olivier et al

in Nature (2017), 542

One focus of modern astronomy is to detect temperate terrestrial exoplanets well-suited for atmospheric characterisation. A milestone was recently achieved with the detection of three Earth-sized planets ... [more ▼]

One focus of modern astronomy is to detect temperate terrestrial exoplanets well-suited for atmospheric characterisation. A milestone was recently achieved with the detection of three Earth-sized planets transiting (i.e. passing in front of) a star just 8% the mass of the Sun 12 parsecs away. Indeed, the transiting configuration of these planets combined with the Jupiter-like size of their host star - named TRAPPIST-1 - makes possible indepth studies of their atmospheric properties with current and future astronomical facilities. Here we report the results of an intensive photometric monitoring campaign of that star from the ground and with the Spitzer Space Telescope. Our observations reveal that at least seven planets with sizes and masses similar to the Earth revolve around TRAPPIST-1. The six inner planets form a near-resonant chain such that their orbital periods (1.51, 2.42, 4.04, 6.06, 9.21, 12.35 days) are near ratios of small integers. This architecture suggests that the planets formed farther from the star and migrated inward. The seven planets have equilibrium temperatures low enough to make possible liquid water on their surfaces. [less ▲]

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See detailL’imprimerie à Bruxelles sous les archiducs Albert et Isabelle (1598-1633)
Adam, Renaud ULg

Conference (2017, February 23)

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See detailL’impôt des sociétés dans une perspective internationale : entre concurrence et convergence
Richelle, Isabelle ULg

Scientific conference (2017, February 23)

Réformer l’imposition des sociétés implique de tenir compte de sa place dans le système fiscal. L’on songe à l’articulation avec l’impôt des personnes physiques, auquel sont soumis les entreprises ... [more ▼]

Réformer l’imposition des sociétés implique de tenir compte de sa place dans le système fiscal. L’on songe à l’articulation avec l’impôt des personnes physiques, auquel sont soumis les entreprises personnelles et les actionnaires individuels. Par ailleurs, est également abordée la question de l’efficacité des incitants fiscaux à l’Isoc, notamment en matière d’investissement, de recherche ou d’environnement. - Les mutations du cadre fiscal international réduisent fortement la marge de manœuvre du législateur belge. Les initiatives de l’OCDE (BEPS) et de l’Union européenne obligent la Belgique à repenser sa politique dite « de niches fiscales » et pourraient déboucher vers une plus forte convergence des systèmes fiscaux. En parallèle, il faut tenir compte des réformes mises en œuvre dans les autres Etats européens, qui eux aussi cherchent à s’adapter au nouveau contexte tout en restant compétitifs [less ▲]

Detailed reference viewed: 35 (4 ULg)