Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailThe evolution of the Fair Trade organisational landscape in France and in Belgium
Huybrechts, Benjamin ULg

Conference (2008, May 14)

Parallel to the dramatic growth of its sales and public awareness, the Fair Trade movement has seen its organisational landscape become increasingly diversified. While Fair Trade nonprofit pioneers were ... [more ▼]

Parallel to the dramatic growth of its sales and public awareness, the Fair Trade movement has seen its organisational landscape become increasingly diversified. While Fair Trade nonprofit pioneers were initially relatively homogeneous in terms of goals and structures, the economic development of the initiative, driven by the sales of Fair Trade products in mainstream distribution channels, has led to the emergence of a multitude of new actors with much more heterogeneous behaviours – in spite of the general trend towards a stronger market orientation – (Gendron, 2004; Moore, 2004; Nicholls & Opal, 2005; Renard, 2003). When observing the evolution of Fair Trade organisations (FTOs), i.e., organisations claiming to be totally dedicated to Fair Trade, three trends can be observed: Fair Trade pioneers have adopted more business-oriented profiles and more complex and specialised organisational structures; New small Fair Trade businesses have emerged with a stronger economic specialisation on a particular product or distribution channel ; « Old » and « new » FTOs increasingly gather into networks with two types of purposes: to promote Fair Trade and to have a minimum political representation (advocacy networks) and to face common socio-economic challenges (socio-economic networks). The goal of this contribution is to analyse these three trends with the help of a sample of nearly fourty FTOs in Belgium and in the French Rhône-Alpes region. We can thus illustrate the three trends on the basis of both general observations and precise examples. We also try to compare the two regions and to explore to what extent the evolution of FTOs reveals more global trends within the Fair Trade movement. [less ▲]

Detailed reference viewed: 70 (3 ULg)
Full Text
See detailThe evolution of the inorganic fluorine budget since the mid-1980s based on FTIR measurements at northern mid-latitudes
Duchatelet, Pierre ULg; Feng, Wuhu; Chipperfield, Martyn et al

in Geophysical Research Abstracts (2011)

Fluorine enters the stratosphere principally in the form of CFCs (chlorofluorocarbons, mainly CFC-12 and CFC-11), HCFCs (hydrochlorofluorocarbons, mainly HCFC-22) and HFCs (hydrofluorocarbons, mainly HFC ... [more ▼]

Fluorine enters the stratosphere principally in the form of CFCs (chlorofluorocarbons, mainly CFC-12 and CFC-11), HCFCs (hydrochlorofluorocarbons, mainly HCFC-22) and HFCs (hydrofluorocarbons, mainly HFC-134a) which have been (or are still) widely emitted at ground level by human activities. In the lower stratosphere, the photolysis of these halogenated source gases leads to the formation of the two fluorine reservoirs COClF and COF2. The subsequent photolysis of these two compounds frees F atoms, which principally react with CH4 and H2O to form the extremely stable HF gas, by far the dominant fluorine reservoir in the middle and upper stratosphere. Despite the fact that fluorine does not significantly contribute in stratospheric ozone depletion, measurements of the concentrations of individual F-containing species in different altitude ranges of the atmosphere are important as they reflect the amounts of anthropogenic gases transported into the middle atmosphere as well as their decomposition. Such measurements also provide insight into the partitioning between major fluorine source gases (which are potent greenhouse gases) and reservoirs and allows a global inventory of organic (CFy), inorganic (Fy) and total (FTOT) fluorine burdens to be monitored as a function of time. Indeed, regular updates of such inventories are important as the partitioning between F-containing gases in the stratosphere is continually evolving as emissions of anthropogenic gases from the surface change, principally as a consequence of the progressive ban on the production of CFCs and HCFCs adopted by the Montreal Protocol and its subsequent Amendments and Adjustments. To complement recent studies regarding fluorine species (Duchatelet et al., 2009, 2010, 2011; Mahieu et al., 2011), this communication presents the time series of the inorganic fluorine budget Fy over the last twenty-five years, based on HF and COF2 total column amounts derived from high resolution Fourier transform infrared (FTIR) solar spectra recorded at Jungfraujoch (46.5°N, 8.0°E, 3580m asl). A trend analysis of our HF, COF2 and Fy time series is performed and discussed in the context of past and current emissions of halogenated source gases. Comparisons with model and space data are also included. [less ▲]

Detailed reference viewed: 35 (9 ULg)
Full Text
Peer Reviewed
See detailEvolution of the Io footprint brightness I: Far-UV observations
Bonfond, Bertrand ULg; Hess, Sébastien; Gérard, Jean-Claude ULg et al

in Planetary and Space Science (2013), 88

The Io footprint (IFP) is a set of auroral spots and an extended tail resulting from the strong interaction between Io and the Jovian magnetosphere. For the first time, we present measurements of the ... [more ▼]

The Io footprint (IFP) is a set of auroral spots and an extended tail resulting from the strong interaction between Io and the Jovian magnetosphere. For the first time, we present measurements of the brightness and precipitated power for each individual spot, using the image database gathered from 1997 to 2009 with the Hubble Space Telescope in the Far-UV domain. We show that the relative brightness of the spots varies with the System III longitude of Io. Moreover, our novel measurement method based on 3D simulations of the auroral features allows to derive the precipitated energy fluxes from images on which the emission region is observed at a slant angle. Peak values as high as 2 W/m² are observed for the main spot, probably triggering a localized and sudden heating of the atmosphere. Additionally, strong brightness differences are observed from one hemisphere to another. This result indicates that the location of Io in the plasma torus is not the only parameter to control the brightness, but that the magnetic field asymmetries also play a key role. Finally, we present new data confirming that significant variations of the spots' brightness on timescales of 2-4 minutes are ubiquitous, which suggests a relationship with intermittent double layers close to Jovian surface. [less ▲]

Detailed reference viewed: 67 (32 ULg)
Full Text
Peer Reviewed
See detailEvolution of the Io Footprint Brightness II: Modeling
Hess, Sébastien; Bonfond, Bertrand ULg; Chantry, Virginie ULg et al

in Planetary and Space Science (2013), 88

The interaction of Io with the Jovian magnetosphere creates the best known and brightest satellite-controlled aurorae in our solar system. These aurorae are generated by the precipitation of electrons ... [more ▼]

The interaction of Io with the Jovian magnetosphere creates the best known and brightest satellite-controlled aurorae in our solar system. These aurorae are generated by the precipitation of electrons, which are accelerated by the Alfvén waves carrying the current between the satellite and the planet. A recent study computed the energy deposited on top of Jupiter's ionosphere due to the electron precipitation and retrieved the correct mean brightness of Io-related aurorae. The model developed in this study takes into account the acceleration mechanism and the Alfvén wave propagation effects. We use the same method to investigate the brightness variation of the different components of the Io footprint as a function of longitude. These observations are discussed in a companion paper. We identify several effects that act together to modulate the footprint brightness such as Alfvén wave reflections, magnetic mirroring of the electrons, the local interaction at Io and kinetic effects close to Jupiter. We identify the effects contributing the most to the modulation of the brightnesses of the three brightest components of the Io footprints: the main and reflected Alfvén wing spots and the transhemispheric electron spot. We show in particular that the modulation of the efficiency of the electron acceleration can be of greater importance than the modulation of the power generated at Io. We reproduce the average modulation of the spot brightnesses and present an extensive discussion of possible explanations for the observed features not reproduced by our model. [less ▲]

Detailed reference viewed: 24 (8 ULg)
See detailEvolution of the Io footprint morphology
Bonfond, Bertrand ULg; Grodent, Denis ULg; Gérard, Jean-Claude ULg et al

Conference (2008, April)

Detailed reference viewed: 4 (0 ULg)
Full Text
See detailEvolution of the Kızılırmak river and its interaction with the North Anatolian Fault, Turkey
Drab, Laureen; Hubert, Aurelia ULg; Benedetti, Lucilla et al

in AGU Abstract (2010, December)

Detailed reference viewed: 44 (7 ULg)
Full Text
Peer Reviewed
See detailEvolution of the Peierls distortion in liquid As xSb 1-x compounds
Raty, Jean-Yves ULg; Gaspard, Jean-Pierre ULg; Ceolin, R. et al

in Journal of Non-Crystalline Solids (1998), 232-234

The local order in the liquid binary alloy As xSb 1-x (0lesxles1) is studied by short-wavelength (lambda=0.7 Aring) neutron scattering. The coordination number (Z) and the interatomic distances (d) are ... [more ▼]

The local order in the liquid binary alloy As xSb 1-x (0lesxles1) is studied by short-wavelength (lambda=0.7 Aring) neutron scattering. The coordination number (Z) and the interatomic distances (d) are analyzed in terms of the As concentration: Z increases continuously, from a value of 3.5 for pure arsenic to a value of 6.3 for pure antimony, whereas d shows a departure from Vegard's rule. The interatomic distance increases in the range 0.15lesxles1.00 and is almost constant in the range 0.00lesxles0.15. A simple tight-binding model is developed, which indicates that the relevant parameter is the hardness of the core repulsion between the atoms [less ▲]

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailEvolution of the Peierls distortion in liquid AsxSb1-x compounds
Raty, Jean-Yves ULg; Gaspard, Jean-Pierre ULg; Céolin, R. et al

in Journal of Non-Crystalline Solids (1998), 232-234

The local order in the liquid binary alloy AsxSb1-x (0 ≤ x ≤ 1) is studied by short-wavelength (λ = 0.7 Å) neutron scattering. The coordination number (Z) and the interatomic distances (d) are analyzed in ... [more ▼]

The local order in the liquid binary alloy AsxSb1-x (0 ≤ x ≤ 1) is studied by short-wavelength (λ = 0.7 Å) neutron scattering. The coordination number (Z) and the interatomic distances (d) are analyzed in terms of the As concentration: Z increases continuously, from a value of 3.5 for pure arsenic to a value of 6.3 for pure antimony, whereas d shows a departure from Vegard's rule. The interatomic distance increases in the range 0.15 ≤ x ≤ 1.00 and is almost constant in the range 0.00 ≤ x ≤ 0.15. A simple tight-binding model is developed, which indicates that the relevant parameter is the hardness of the core repulsion between the atoms. © 1998 Elsevier Science B.V. All rights reserved. [less ▲]

Detailed reference viewed: 12 (0 ULg)
Full Text
Peer Reviewed
See detailEvolution of the periodicity of the W UMa system Epsilon CrA
Manfroid, Jean ULg; Heck, A.; Lunel, M. et al

in Astronomy and Astrophysics (1987), 176

Photometric uvby observations of Epsilon CrA obtained with the 1-m telescope at ESO during 1985 are compiled in tables along with published photometry from the period 1960-1984 and analyzed ... [more ▼]

Photometric uvby observations of Epsilon CrA obtained with the 1-m telescope at ESO during 1985 are compiled in tables along with published photometry from the period 1960-1984 and analyzed comprehensively. The results are presented in O-C diagrams and discussed, and a relative increase of 0.00001 in the period of the object is detected. It is pointed out that this change may have been gradual (over a 5-10-yr period) or abrupt (at about HJD 2,440,000), but that the period appears to have become stable again in the most recent observations. [less ▲]

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailEvolution of the polarization of the optical afterglow of the γ-ray burst GRB030329
Greiner, Jochen; Klose, Sylvio; Reinsch, Klaus et al

in Nature (2003), 426

The association of a supernova with GRB030329 strongly supports the `collapsar' model of γ-ray bursts, where a relativistic jet forms after the progenitor star collapses. Such jets cannot be spatially ... [more ▼]

The association of a supernova with GRB030329 strongly supports the `collapsar' model of γ-ray bursts, where a relativistic jet forms after the progenitor star collapses. Such jets cannot be spatially resolved because γ-ray bursts lie at cosmological distances; their existence is instead inferred from `breaks' in the light curves of the afterglows, and from the theoretical desire to reduce the estimated total energy of the burst by proposing that most of it comes out in narrow beams. Temporal evolution of the polarization of the afterglows may provide independent evidence for the jet structure of the relativistic outflow. Small-level polarization (~1-3 per cent) has been reported for a few bursts, but its temporal evolution has yet to be established. Here we report polarimetric observations of the afterglow of GRB030329. We establish the polarization light curve, detect sustained polarization at the per cent level, and find significant variability. The data imply that the afterglow magnetic field has a small coherence length and is mostly random, probably generated by turbulence, in contrast with the picture arising from the high polarization detected in the prompt γ-rays from GRB021206 (ref. 18). [less ▲]

Detailed reference viewed: 10 (0 ULg)
See detailEvolution of the populations of Cystoseira balearica (Phaeophyceae) and epiphytic Bangiophyceae in the Bay of Calvi (Corsica) in the last eight years
Hoffman, Lucien; Clarisse, Serge; Detienne, Xavier et al

in Bulletin de la Société Royale des Sciences de Liège (1988), 4-5

In a number of stations covering the Bay of Calvi (Corsica, Mediterranean Sea) we studied the development of the macroscopic brown alga Cyctoseira balearica and of the epiphytic microscopic Bangiophyceae ... [more ▼]

In a number of stations covering the Bay of Calvi (Corsica, Mediterranean Sea) we studied the development of the macroscopic brown alga Cyctoseira balearica and of the epiphytic microscopic Bangiophyceae. Cystoseira balearica is a major component of infralittoral communities on rocky substrates and Bangiophyceae have been considered indicators of eutrophication. The epiphytic Bangiophyceae have indeed their optimal developement near the sewages discharges (especially in summer) and near the town of Calvi. Since 1981 an increase is observed in the abundance of the Bangiophycae. Cystoseira balearica, a pollution-sensitive species, is not present in the harbours of the town of Cavi and near the sewage dicharges. Since 1980 the coverage and the standing crop of this alga have decreased. The increase of Bangiophyceae and the concurrent decrease of Cyctoseira balearica seem to indicate an increasing pollution of the waters of the Bay of Calvi in the period 1980 - 1988. [less ▲]

Detailed reference viewed: 95 (18 ULg)
Full Text
See detailEvolution of the prevalence and characteristics of anemia in inflammatory bowel diseases between 1993 and 2003
Vijverman, A.; Piront, Patricia ULg; Belaiche, Jacques ULg et al

in Acta Gastro-Enterologica Belgica (2006), 69(1, Jan-Mar), 1-4

Introduction : Anemia has been considered as an overlooked complication of inflammatory bowel disease. Studies dating back to the 80ties and the 90ties have shown 30% of anemia among inflammatory bowel ... [more ▼]

Introduction : Anemia has been considered as an overlooked complication of inflammatory bowel disease. Studies dating back to the 80ties and the 90ties have shown 30% of anemia among inflammatory bowel disease (IBD) patients. More recently, the broader use of immunosuppressive drug and infliximab allowing better mucosal healing as well as a more aggressive treatment of anemia, including the use of safer form of IV iron, may have influenced the prevalence of anemia among IBD patients. Our aim was to asses the prevalence and characteristics of anemia among two cohorts of IBD patients at 10 years interval and to look for associated clinical or demographic factors. Methods: using the IBD patients register of one senior gastroenterologist, we identified IBD patients he had consecutively seen and who had blood test at the outpatient clinic during the years 1993 and 2003. Demographic and clinical characteristics, treatment for Crohn's disease, blood test results and treatment of anemia were recorded and compared between these two cohorts. Anemia was defined as an hemoglobin level lower than the normal value of the laboratory of our hospital. Results : 80 and 90 patients were identified in 1993 and 2003, respectively. There was no significant difference between the two cohorts, according to age, gender, disease type, duration or location. There were 27/80 (33.8%) and 15/90 (16.7%) anemic patients in 1993 and 2003, respectively (P = 0.013). The prevalence of severe anemia (hemoglobin level < 10.5 g/100 ml) was similar in the two cohorts (6.3% and 5.6%). Characteristics of the anemia were similar in the two cohorts with a majority of iron deficiency anemia and inflammatory anemia. Ferritin and CRP levels were not significantly different in the two cohorts. The only significant difference was a more frequent use of immunosuppressive treatment and infliximab in 2003 than in 1993 (33.3% vs. 13.8%; P = 0.0038, RR :0.41, 0.22-0.77) Conclusions : Prevalence of mild to moderate anemia has significantly decreased in our population over the last 10 years. The only difference detected between the two cohorts was the increased use of immunosuppressive drug (mainly azathioprine). [less ▲]

Detailed reference viewed: 39 (0 ULg)
See detailEvolution of the shoot density of the Posidonia oceanica bed of Calvi Bay (Corsica).
Soullard, Mady; Dauby, Patrick ULg; Bouquegneau, Jean-Marie ULg

Conference (1992, February)

Detailed reference viewed: 10 (0 ULg)
Full Text
Peer Reviewed
See detailEvolution of the surface chemistry of carbon xerogels with very different textural properties by chemical activation and oxidation
Zubizaretta, Leire; Arenillas, A.; Pirard, Jean-Paul ULg et al

in Proceedings of the International Carbon Conference 2009 (2009)

Detailed reference viewed: 12 (1 ULg)
Peer Reviewed
See detailEvolution of the surface chemistry of carbon xerogels with very different textural properties by chemical activation and oxidation
Zubizarreta, Leire; Arenillas, A.; Pirard, Jean-Paul ULg et al

Poster (2009, June 14)

Detailed reference viewed: 19 (1 ULg)
Full Text
See detailEvolution of the theoretical power spectrum of solar-like oscillations along the ascending phase on the red giant branch.
Grosjean, Mathieu ULg; Montalban Iglesias, Josefa ULg; Samadi, Reza et al

Poster (2012, November)

CoRoT and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. An important question comes from the observation of mixed ... [more ▼]

CoRoT and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. An important question comes from the observation of mixed modes : When during the star’s ascension on the RGB are mixed-modes more likely to be detectable ? We follow the evolution of a star on the RGB and investigate the effect of its ascension on theoretical power spectrum. Equilibrium models (computed with the code ATON) represent four different stages of a star on the RGB. The mass of the star (1.5M") is in the typical mass range of stars observed by CoRoT and Kepler. We used a non-radial non-adiabatic code to compute the theoretical solar-like oscillations of these models. An important output of these calculations is the theoretical lifetimes of the modes. Then we computed the oscillation amplitudes through a stochastic excitation model. These computations allow us to draw theoretical power spectrum and discuss the possibility to observe mixed-modes at different evolutionary stages on the RGB. We found that structure modifications in a star ascending the RGB have an important impact on theoretical power spectrum of solar-like oscillations. Efficiencies of trapping and lifetimes of mixed modes are indeed strongly affected by this evolution. [less ▲]

Detailed reference viewed: 12 (2 ULg)
Full Text
See detailEvolution of the theoretical power spectrum of solar-like oscillations along the ascending phase on the red giant branch.
Grosjean, Mathieu ULg; Dupret, Marc-Antoine ULg; Belkacem, Kevin et al

in Astronomical Society of the Pacific Conference Series (2013, December), 479

CoRoT and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. An important question comes from the observation of mixed ... [more ▼]

CoRoT and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. An important question comes from the observation of mixed modes : When during the star’s ascension on the RGB are mixed-modes more likely to be detectable ? We follow the evolution of a star on the RGB and investigate the effect of its ascension on theoretical power spectrum. Equilibrium models (computed with the code ATON) represent four different stages of a star on the RGB. The mass of the star (1.5M") is in the typical mass range of stars observed by CoRoT and Kepler. We used a non-radial non-adiabatic code to compute the theoretical solar-like oscillations of these models. An important output of these calculations is the theoretical lifetimes of the modes. Then we computed the oscillation amplitudes through a stochastic excitation model. These computations allow us to draw theoretical power spectrum and discuss the possibility to observe mixed-modes at different evolutionary stages on the RGB. We found that structure modifications in a star ascending the RGB have an important impact on theoretical power spectrum of solar-like oscillations. Efficiencies of trapping and lifetimes of mixed modes are indeed strongly affected by this evolution. [less ▲]

Detailed reference viewed: 18 (2 ULg)