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See detailA capillary Archimedes’ screw
Darbois-Texier, Baptiste ULg; Dorbolo, Stéphane ULg

Conference (2014, November 23)

As used by Egyptians for irrigation and reported by Archimedes, a screw turning inside a hollow pipe can pull out a fluid againt gravity. At a centimetric scale, an analagous system can be found with a ... [more ▼]

As used by Egyptians for irrigation and reported by Archimedes, a screw turning inside a hollow pipe can pull out a fluid againt gravity. At a centimetric scale, an analagous system can be found with a drop pending on a rotating spiral which is tilted toward the horizontal. The ascent of the drop to the top of the spiral is considered and a theoretical model based on geometrical considerations is proposed. The climb of the drop is limited by the fluid deposition on the screw at high capillary number and by a centrifugation phenomenon. We find out the range of fluid proprities and spiral characteristics for which an ascending motion of the drop is possible. Finally we discuss the efficiency of such system to extract a fluid from a bath at a centrimetric scale. [less ▲]

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See detailFoucault et Deleuze et Sami-Ali : postmodernité et psychothérapie.
Englebert, Jérôme ULg

Conference (2014, November 22)

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See detailPhysical and bacterial controls on inorganic nutrients and dissolved organic carbon during a sea ice growth and decay experiment
Zhou, Jiayun ULg; Delille, Bruno ULg; Kaartokallio, Hermanni et al

in Marine Chemistry (2014), 166

We investigated how physical incorporation, brine dynamics and bacterial activity regulate the distribution of inorganic nutrients and dissolved organic carbon (DOC) in artificial sea ice during a 19-day ... [more ▼]

We investigated how physical incorporation, brine dynamics and bacterial activity regulate the distribution of inorganic nutrients and dissolved organic carbon (DOC) in artificial sea ice during a 19-day experiment that included periods of both ice growth and decay. The experiment was performed using two series of mesocosms: the first consisted of seawater and the second consisted of seawater enriched with humic-rich river water. We grew ice by freezing the water at an air temperature of -14 °C for 14 days after which ice decay was induced by increasing the air temperature to -1 °C. Using the ice temperatures and bulk ice salinities, we derived the brine volume fractions, brine salinities and Rayleigh numbers. The temporal evolution of these physical parameters indicate that there was a succession of 3 stages in the brine dynamics: forced-convection, followed by bottom convection during ice growth, and then brine stratification during ice decay. The major findings are: (1) the incorporation of dissolved compounds (nitrate, nitrite, ammonium, phosphate, silicate, and DOC) into the sea ice was not conservative (relative to salinity) during ice growth. Brine convection clearly influenced the incorporation of the dissolved compounds, since the non-conservative behavior of the dissolved compounds was particularly pronounced in the absence of brine convection. (2) Bacterial activity further regulated nutrient availability in the ice: ammonium and nitrite accumulated as a result of remineralization processes, although bacterial production was too low to induce major changes in DOC concentrations. (3) Different forms of DOC have different properties and hence incorporation efficiencies. In particular, the terrestrially-derived DOC from the river water was less efficiently incorporated into sea ice than the DOC in the seawater. Therefore the main factors regulating the distribution of the dissolved compounds within sea ice are clearly a complex interaction of brine dynamics, biological activity and in the case of dissolved organic matter, the physico-chemical properties of the dissolved constituents themselves. [less ▲]

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See detailPerceptual Experiences and their Parts
Dewalque, Arnaud ULg

Scientific conference (2014, November 22)

What is the phenomenal structure of our perceptual experiences? In this talk, I suggest that perceptual experiences – like consciousness in general – have a mereological structure, that is, a structure in ... [more ▼]

What is the phenomenal structure of our perceptual experiences? In this talk, I suggest that perceptual experiences – like consciousness in general – have a mereological structure, that is, a structure in which the most basic relation is that of parthood. I do not provide any definitive argument for this view. I just want to suggest (i) that the mereological approach is untouched by the usual objections coming from the proponents of the Unified Field Theory (James, Searle, Tye), (ii) that the Unified Field Theory faces some important difficulties of its own. [less ▲]

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See detailVers un transport aérien plus écologique et plus économique
Lurkin, Virginie ULg

Conference given outside the academic context (2014)

de l’avion en vol. Mieux, on peut montrer que la position du centre de gravité (qui dépend du chargement de l’avion) affecte la consommation de carburant. Ce résultat revêt une importance majeure dans un ... [more ▼]

de l’avion en vol. Mieux, on peut montrer que la position du centre de gravité (qui dépend du chargement de l’avion) affecte la consommation de carburant. Ce résultat revêt une importance majeure dans un contexte d’augmentation des prix du pétrole et où il s’agit de réduire les émissions polluantes. Pour un transport aérien plus économique, il s’agit aussi, en cas de livraisons à différents endroits, de réduire au maximum les temps de chargements et de déchargements afin de limiter les coûts liés aux paiements des salariés et à l’utilisation de chaque aéroport intermédiaire. Au cours de mon exposé, je présente un modèle mathématique qui vise à trouver le chargement qui minimise la consommation de carburant et les temps de chargements et déchargements. Je partage avec nous les résultats de mes recherches dont les applications garantissent un impact écologique et économique positif. [less ▲]

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See detailLong-term evolution and seasonal modulation of methanol above Jungfraujoch (46.5°N, 8.0°E): Optimisation of the retrieval strategy, comparison with model and independant observations
Bader, Whitney ULg; Stavrakou, T; Muller, J-F et al

in Atmospheric Measurement Techniques (2014), 7

Methanol (CH3OH) is the second most abundant organic compound in the Earth's atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and ... [more ▼]

Methanol (CH3OH) is the second most abundant organic compound in the Earth's atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and upper tropospheric-lower stratospheric partial columns derived from the analysis of high resolution Fourier transform infrared solar spectra recorded at the Jungfraujoch station (46.5° N, 3580 m a.s.l.). The retrieval of methanol is very challenging due to strong absorptions of ozone in the region of the selected υ8 band of CH3OH. Two wide spectral intervals have been defined and adjusted in order to maximize the information content. Methanol does not exhibit a significant trend over the 1995–2012 time period, but a strong seasonal modulation characterized by maximum values and variability in June–July, minimum columns in winter and a peak-to-peak amplitude of 130%. In situ measurements performed at the Jungfraujoch and ACE-FTS occultations give similar results for the methanol seasonal variation. The total and lower tropospheric columns are also compared with IMAGESv2 model simulations. There is no systematic bias between the observations and IMAGESv2 but the model underestimates the peak-to-peak amplitude of the seasonal modulations. [less ▲]

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See detailOn the finiteness and uniqueness of the weighted likelihood estimator of ability in polytomous IRT models
Magis, David ULg; Verhelst, Norman

Conference (2014, November 21)

In item response theory (IRT), the weighted likelihood (WL) estimator has become a central method to estimate ability levels of respondents. Primarily introduced with dichotomous IRT models (Warm, 1989 ... [more ▼]

In item response theory (IRT), the weighted likelihood (WL) estimator has become a central method to estimate ability levels of respondents. Primarily introduced with dichotomous IRT models (Warm, 1989), it was later extended to polytomous IRT models (Samejima, 1998). However, very few information is available about the behavior of the WL estimator, and especially about the uniqueness of the ability estimates as well as their finiteness. The purpose of this talk is to establish that with polytomous item response models, the WL estimator of ability always returns finite values. This result is valid for the class of difference models and divide-by-total models, independently of the number of items and the response patterns. However, such estimates may not necessarily be unique, as the WL solving equation may provide several optimal values. Some examples are considered to illustrate both findings. [less ▲]

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See detailImpact environnemental des stations de méthanisation agricoles
Adam, Gilles ULg

Conference given outside the academic context (2014)

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See detailDouble thermoresponsive di- and triblock copolymers based on N-vinylcaprolactam and N-vinylpyrrolidone: synthesis and comparative study of solution behaviour
Kermagoret, Anthony ULg; Mathieu, Kevin ULg; Thomassin, Jean-Michel ULg et al

in Polymer Chemistry (2014), 5(22), 6534-6544

Poly(N-vinylcaprolactam) (PNVCL) and poly(N-vinylpyrrolidone) (PNVP) are water soluble polymers of interest especially in the biomedical field. Moreover, PNVCL is characterized by a lower critical ... [more ▼]

Poly(N-vinylcaprolactam) (PNVCL) and poly(N-vinylpyrrolidone) (PNVP) are water soluble polymers of interest especially in the biomedical field. Moreover, PNVCL is characterized by a lower critical solution temperature close to 36 °C in water, which makes it useful for the design of thermoresponsive systems. In this context, we used the cobalt-mediated radical polymerization (CMRP) and reaction coupling (CMRC) for synthesizing a series of well-defined NVCL and NVP-based copolymers, including statistical copolymers as well as double thermoresponsive diblocks and triblocks. Dynamic light scattering and turbidimetry analyses highlighted the crucial impact of the copolymer composition and architecture on the cloud point temperature (TCP) of each segment and also their influence on the multistep assembly behaviour of block copolymers. Addition of NaCl enabled us to adjust the inter-TCP range of the di- and triblock in which selective precipitation of one block and self-assembly of the copolymer were favoured. Overall, data presented here provide a basis for the synthesis of a broad range of NVCL/NVP based copolymer architectures with a tunable thermal response in water. [less ▲]

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See detailUne photographie peut-elle faire l’événement ? Document, histoire et mémoire.
Hamers, Jérémy ULg

Conference given outside the academic context (2014)

Detailed reference viewed: 6 (0 ULg)
See detailLa pensée et l'institution psychanalytiques à l'épreuve e la question de l'homosexualité
Naziri, Despina ULg

Scientific conference (2014, November 20)

Detailed reference viewed: 27 (7 ULg)
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See detailTraitements conservateurs de la gonarthrose
Kaux, Jean-François ULg

Conference (2014, November 20)

Detailed reference viewed: 21 (2 ULg)
See detailA Debate on Responsible Research and Innovation
Van Oudheusden, Michiel ULg

Conference (2014, November 20)

In the space of just a few years the concept of Responsible Research and Innovation (RRI), or in Dutch Maatschappelijk verantwoord innoveren (MVI), has gained considerable ground: NWO has an MVI-program ... [more ▼]

In the space of just a few years the concept of Responsible Research and Innovation (RRI), or in Dutch Maatschappelijk verantwoord innoveren (MVI), has gained considerable ground: NWO has an MVI-program that has so far funded three rounds of research proposals; Horizon 2020 regularly refers to RRI; and there is now a new journal devoted to RRI. In this panel we focus on the following questions: • How could the concept become so popular in such a relatively short time? • What, if anything, is new in RRI, when we compare it to e.g. CTA, participatory TA, Public Engagement, etc? • If we want to make research and innovation more responsible and responsive to society’s needs, what are the opportunities and obstacles? • What are the conditions for successful mainstreaming of RRI? Panel members Frank Kupper (Athena Institute) Hub Zwart (Centre for Society and the Life Scences), Michiel van Oudheusden (author of a dissertation on Flemish RRI initiatives), and Tsjalling Swierstra (co-founder of the Journal for RI) share their thoughts with colleagues in the audience. [less ▲]

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See detailSolar Wind Interaction with the Magnetosphere of Jupiter : Impact on the Magnetopause and the Aurorae
Bonfond, Bertrand ULg; Grodent, Denis ULg; Gérard, Jean-Claude ULg et al

Conference (2014, November 20)

The outcome of the interaction between the solar wind and the Jovian magnetic field bears many differences compared to the Earth's case. At Earth, the solar wind is the major particle and energy source in ... [more ▼]

The outcome of the interaction between the solar wind and the Jovian magnetic field bears many differences compared to the Earth's case. At Earth, the solar wind is the major particle and energy source in the magnetosphere. At Jupiter, the tremendous volcanism on the moon Io is the main plasma source and Jupiter's rapid rotation (relative to its size) is the main energy source for the particles populating its magnetosphere. Combined with a weaker solar wind pressure and a larger Alfvén Mach number as the distance from the Sun increases, all these parameters modify the relative importance of large scale Dungey reconnection and viscous interaction at the magnetopause. In order to study these differences, here we present a statistical analysis of magnetopause waves and flux tube event on the Jovian magnetopause, based on in-situ measurement from the spacecraft that flew-by or orbited around Jupiter. Moreover, variations of the solar wind have significant impact on the Jovian magnetospheric current systems and such changes reflect on the aurora. In this presentation, we will also review the recent findings concerning the aurora at Jupiter and their relationship with the solar wind. [less ▲]

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See detailENMG non classique
WANG, François-Charles ULg

Scientific conference (2014, November 20)

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See detailPremières mises en liberté avant jugement devant la Cour pénale internationale
Deprez, Christophe ULg

E-print/Working paper (2014)

Ce billet évoque les premières libérations avant jugement intervenues devant la Cour pénale internationale (octobre 2014). Après avoir été soumis à un comité de lecture, il a été publié sur le 'blogue' de ... [more ▼]

Ce billet évoque les premières libérations avant jugement intervenues devant la Cour pénale internationale (octobre 2014). Après avoir été soumis à un comité de lecture, il a été publié sur le 'blogue' de la Clinique de droit international pénal et humanitaire de l'Université de Laval. [less ▲]

Detailed reference viewed: 7 (0 ULg)