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See detailLe rail belge s'ouvre à la concurrence. Peut-on tirer parti de l'expérience étrangère ?
Gautier, Axel ULg

in Regards économiques (2004)

La Commission européenne vient de décider d’ouvrir d’ici 2010 l’ensemble du marché ferroviaire à la concurrence. À l’avenir, la SNCB ne sera plus la seule compagnie à transporter des passagers dans notre ... [more ▼]

La Commission européenne vient de décider d’ouvrir d’ici 2010 l’ensemble du marché ferroviaire à la concurrence. À l’avenir, la SNCB ne sera plus la seule compagnie à transporter des passagers dans notre pays. Dans ce numéro de Regards économiques, nous analysons au travers de l’expé- rience de deux pays, l’Allemagne et l’Angleterre, les conséquences de la libéralisation du secteur sur le rail belge. [less ▲]

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See detailLa sensibilité à l'anxiété, une synthèse
Chaboteaux, Martine; Delvaux, Muriel ULg; Etienne, Anne-Marie ULg

in Revue Francophone de Clinique Comportementale et Cognitive (2004), IX(2), 1-8

This article makes a literature's overview about the concept of anxiety sensitivity, i.e. fear of anxiety sensations . After the definition of anxiety sensitivity and description of the main theorical ... [more ▼]

This article makes a literature's overview about the concept of anxiety sensitivity, i.e. fear of anxiety sensations . After the definition of anxiety sensitivity and description of the main theorical models, methods of measurement will be shown. Then, the comorbidity between anxiety sensitivity and anxiety disorders, more specifically panic disorder, as well as between anxiety sensitivity and hyperventilation, depression and chronic health disorders will be examined. At last, the treatment of anxiety sensitivity's benefits and some research perspectives will be considered. [less ▲]

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See detailQuasi-simultaneous XMM-Newton and VLA observation of the non-thermal radio emitter HD 168112 (O5.5III(f+))
De Becker, Michaël ULg; Rauw, Grégor ULg; Blomme, Ronny et al

in Astronomy and Astrophysics (2004), 420

We report the results of a multiwavelength study of the non-thermal radio emitter HD 168112 (O5.5III(f+)). The detailed analysis of two quasi-simultaneous XMM-Newton and VLA observations reveals strong ... [more ▼]

We report the results of a multiwavelength study of the non-thermal radio emitter HD 168112 (O5.5III(f+)). The detailed analysis of two quasi-simultaneous XMM-Newton and VLA observations reveals strong variability of this star both in the X-ray and radio ranges. The X-ray observations separated by five months reveal a decrease of the X-ray flux of ˜30%. The radio emission on the other hand increases by a factor 5-7 between the two observations obtained roughly simultaneously with the XMM-Newton pointings. The X-ray data reveal a hard emission that is most likely produced by a thermal plasma at kT ˜ 2-3 keV while the VLA data confirm the non-thermal status of this star in the radio waveband. Comparison with archive X-ray and radio data confirms the variability of this source in both wavelength ranges over a yet ill defined time scale. The properties of HD 168112 in the X-ray and radio domain point towards a binary system with a significant eccentricity and an orbital period of a few years. However, our optical spectra reveal no significant changes of the star's radial velocity suggesting that if HD 168112 is indeed a binary, it must be seen under a fairly low inclination. [less ▲]

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See detailEvaluation environnementale de l'exploitation agricole: La méthode de l'écobilan
Debouche, Charles ULg; Lambin, Jean

in Travaux & Innovations (2004), (109), 20-22

Les principes du développement durable couvrent les domaines social, économique, et environnemental. En conséquence, l’analyse de la « durabilité » d’une exploitation agricole implique que soient évaluées ... [more ▼]

Les principes du développement durable couvrent les domaines social, économique, et environnemental. En conséquence, l’analyse de la « durabilité » d’une exploitation agricole implique que soient évaluées ses caractéristiques dans ces trois domaines. Est ici présentée une évaluation environnementale de l’exploitation agricole, qui doit évidemment être complétée par son analyse sociale et économique, non couverte par l’écobilan présenté ci-dessous. Cette méthode originale est issue d’une recherche appliquée réalisée par la Faculté universitaire des Sciences agronomiques de Gembloux (Belgique). [less ▲]

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See detailAntioxidant power of phytochemicals from Psidium guajava leaf.
Qian, He; Nihorimbere, Venant ULg

in Journal of Zhejiang University. Science. B (2004), 5(6), 676-683

ried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically ... [more ▼]

ried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 +/-15.5 and 511.6+/-6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH*) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH* color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC(50) and the time needed to reach the steady state to EC(50) concentration (T(EC(50))) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC(50). This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants. [less ▲]

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See detailLa mise en valeur des vestiges archéologiques urbains. Le projet européen Appear
Teller, Jacques ULg; Warnotte, A.

in Cahiers de l'Urbanisme (Les) (2004), (50),

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See detailLe phenomene de Raynaud
Sprynger, Muriel ULg

in Revue Médicale de Liège (2004), 59(6), 378-84

Raynaud's phenomenon (RP) is a common vascular disorder characterized by a recurrent transient vasospasm of the fingers and toes on exposure to cold or with emotional stress. Clinical criteria are used to ... [more ▼]

Raynaud's phenomenon (RP) is a common vascular disorder characterized by a recurrent transient vasospasm of the fingers and toes on exposure to cold or with emotional stress. Clinical criteria are used to distinguish patients with primary or idiopathic RP (formely Raynaud's disease) from those with secondary RP (formely Raynaud's syndrome). They include history, general physical examination, capillaroscopy, test for antinuclear antibody and erythrocyte sedimentation rate. More specific exams may be needed in selective cases. Excluding RP of occupational origin, the most common cause of secondary RP is a connective tissue disease (particularly scleroderma). RP may precede other clinical symptoms by several years, but most patients with RP will not progress to systemic disease. Nevertheless, primary RP may cause significant disability. We review the pathophysiology and clinical criteria of the disorder. Unfortunately, management of PR is still empirical and largely supportive. [less ▲]

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See detailSédimentologie de la plate-forme carbonatée frasnienne belge
Da Silva, Anne-Christine ULg

Doctoral thesis (2004)

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See detailTCP Vegas-like algorithm for layered multicast transmission
Ait-Hellal, Omar; Leduc, Guy ULg

in Communications in Computing (2004, June)

Layered multicast is probably the most elegant solution to tackle the heterogeneity problem in multicast delivery of real-time multimedia streams. However, the multiple join experiments carried out by ... [more ▼]

Layered multicast is probably the most elegant solution to tackle the heterogeneity problem in multicast delivery of real-time multimedia streams. However, the multiple join experiments carried out by different receivers in order to detect the available bandwidth make it hard to achieve fairness. In the present paper, we present a simple protocol, inspired from TCP-Vegas, that reduces considerably the unnecessary join experiments while achieving intra-session and inter-session fairness as well as being TCP-Friendly. [less ▲]

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See detailSolving the m-TSP Problem with Stochastic or Time Dependent Demands
Louveaux, François; Schyns, Michael ULg

in Opasanon, S.; Miller-Hooks, E. (Eds.) Proceedings of TRISTAN V (Triennial Symposium on Transportation Analysis) (2004, June)

There are many examples of problems in transportation where some elements are uncertain. In the distribution of goods as well as systems responding to calls for emergency, demands typically occur in a ... [more ▼]

There are many examples of problems in transportation where some elements are uncertain. In the distribution of goods as well as systems responding to calls for emergency, demands typically occur in a random fashion. Transportation systems have thus to be created in face of uncertainty about future levels of demands, making strategic decisions difficult to take. Similarly, traffic conditions vary randomly over time and travel routes are usually designed in face of uncertainty about traffic conditions, hence about effective travel times. Stochastic models, i.e. models that take uncertainty explicitly into account, have thus a central role to play in transportation. [less ▲]

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See detailLa rispéridone en pédopsychiatrie. Sa place dans l’ensemble de la nosologie, dont les diagnostics non-psychotiques, les liens avec la clinique, des modèles neurophysiologiques d’actions, dont une amélioration de la synthèse des perceptions des émotions ,contexte sociologique et aspects éthiques et anthropologiques.
Scholl, Jean-Marc ULg

in Neurone (2004), 9(4), 1-34

Some children benefit greatly from atypical antipsychotics. In some cases, their use markedly improves these children’s relational and developmental prognosis. The indications for use also include, as is ... [more ▼]

Some children benefit greatly from atypical antipsychotics. In some cases, their use markedly improves these children’s relational and developmental prognosis. The indications for use also include, as is well-known, non-psychotic diagnoses such as: Borderline Personality Disorder, Separation Anxiety Disorder, manic states, and mood swings. This article is the fruit of clinical experience with one atypical antipsychotic, risperdidone, involving more than 230 patients in childhood (80%) or adolescence (20%). After having briefly discussed the atypical antipsychotics in Section I, we will go on in Section II to specify the conditions of effectiveness (in which psychotherapy plays a part), prescription limits, dosage schedules, and side effects of risperidone in relation to the whole gamut of child pyschiatric nosology, drawing both on personal clinical experience and on relevant studies. Section II concludes with an explanatory metaphor that can be helpfully used to communicate with the child and the parents when the drug is first prescribed. Section II also serves to introduce the main hypothesis I want to present in this paper. First, the majority of anamnestic elements we will have discussed in the section are connected with a neurophysiological deficit in the capacity to synthesize perceptions, and particularly with a difficulty in perceiving affects (more below). Second, risperidone corrects, or, in conjunction with other atypical psychotics, helps to correct, the above-mentioned neurobiological deficit. Third, this suggests the need for an empirically-oriented research program aimed at identifying precisely the diverse clinical entities often lumped together under vague terms like “psychosis,” the exact neurobiological deficits underlying them, and the atypical psychotics---as opposed to the classical neuroleptics---that best correct these deficits. This does not call into question the value of psychotherapy, but rather suggests the need for a holistic, multidisciplinary approach that takes account of all relevant factors: neurobiological, psychological, familial, cultural, and so forth. Section III fleshes out this hypothesis by proposing an original neuropsychological model of risperidone’s action that illuminate the clinical experience discussed in Section II. According to this model, risperidone leads to a significant improvement in the synthesis of the perception of emotions and to a better connection between the different neorological zones associated with memory, thus allowing a greater integration of the perceptions. A significant element in Section III will be a critical review of some of the relevant literature. Section IV brings neurological models into dialogue with psychodynamics in light of some concrete clinical cases. What is offered here is just an initial sketch whose value is above all in the proposed approach, which obviously calls for a subsequent interdisciplinary study. Clinical practise, it is suggested, must attend to the world of feelings and subjectivity as a key to understanding the difficulties of the child and the necessity of psychotherapy in conjunction with drug therapy. Section V puts the difficulty of listening to one’s feelings in the context of contemporary Western society, which is not unconnected with the deterioration in mental health. Section V also tackles the ethics of prescribing antipsychotics like risperidone and of the future research with psychotrophic drugs. Finally, Section V also underlines certain aspects of the human being that the action of risperidone brings to light: man as “a being of perception and receptivity”; man’s “faculties”; and the “intuitive intelligence.” The article ends with a brief reflection on “the sense of the mystery of the human being” in order to set the question of determinism into a wider phenomenological context at whose center stands the undivided unity of the human being within interpersonal communion. [less ▲]

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See detailTechnologies du multimédia, de l'Internet et des télécommunications
Van Droogenbroeck, Marc ULg

Learning material (2004)

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See detailAdaptation of the pull-off test for the evaluation of the superficial cohesion of concrete substrates in repair works: analysis of the test parameters
Courard, Luc ULg; Bissonnette, B.

in Materials and Structures (2004), 37(269), 342-350

Concrete repair works involve most of the time the removal of the damaged or contaminated surface layer. It is necessary to assess the effect of that operation (tool, procedure, etc) upon the integrity of ... [more ▼]

Concrete repair works involve most of the time the removal of the damaged or contaminated surface layer. It is necessary to assess the effect of that operation (tool, procedure, etc) upon the integrity of the residual concrete substrate, prior to the placement of the repair material, since it can affect significantly the adhesion of the repair system. This paper summarizes the findings of a study intended to develop a simple test method for that purpose. After a thorough review of the related scientific documentation, it has been decided to adapt the so-called pull-off test, which is commonly used to determine the bond strength of repair products. An experimental program has been conducted to evaluate the influence of various test parameters on the measured cohesion of a reference concrete surface: transfer plate thickness and diameter, core drilling depth, speed of loading, adhesive type and thickness, and number of tests. A multivaried statistical analysis of the test results clearly shows that the plate diameter and core depth are the most significant parameters, presumably with threshold values, and that there exists a synergetic effect between them. Also, a minimum number of tests can be defined based on the standard deviation and required level of confidence of the results. Overall, the test method shows good potential for a sound quantitative evaluation of a concrete surface mechanical integrity prior to repair, provided that the test parameters are selected properly. [less ▲]

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See detailEtude diachronique, à l’aide de la télédétection, de l’évolution du littoral du sud du delta du Fleuve Rouge (Viet Nam)
de Marneffe, Geneviève; Thrinh, Phan Trong; Tan, Mai Thanh et al

in Bannari, Abderrazak; Blasco (Eds.) Les Xèmes Journées Scientifiques du Réseau Télédétection de l'AUF (2004, May 25)

Dans le cadre de la recherche partagée du réseau de télédétection qui réunit les laboratoires de télédétection de Liège et de Hanoï et dans le cadre des accords de coopération entre le Vietnam et la ... [more ▼]

Dans le cadre de la recherche partagée du réseau de télédétection qui réunit les laboratoires de télédétection de Liège et de Hanoï et dans le cadre des accords de coopération entre le Vietnam et la Région Wallonne (Belgique), l'étude de l'évolution du littoral du sud du delta du Fleuve Rouge a été réalisée. Cette étude comprend deux parties: la première consiste en une présentation générale du delta du Fleuve Rouge. Elle analyse surtout les différents facteurs qui influencent fortement la dynamique littorale (vents, houle, marées…). la deuxième partie est l'étude diachronique du littoral du sud du delta du Fleuve Rouge. Elle s'est effectuée en deux phases : d’abord le traitement et l'analyse de photos aériennes et d'images satellitales, ensuite un travail de vérité-terrain. [less ▲]

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See detailA phase-resolved XMM-Newton campaign on the colliding-wind binary HD 152248
Sana, H.; Stevens, I. R.; Gosset, Eric ULg et al

in Monthly Notices of the Royal Astronomical Society (2004), 350(3), 809-828

We report the first results of an XMM-Newton monitoring campaign of the open cluster NGC 6231 in the Sco OB 1 association. This first paper focuses on the massive colliding-wind binary HD 152248, which is ... [more ▼]

We report the first results of an XMM-Newton monitoring campaign of the open cluster NGC 6231 in the Sco OB 1 association. This first paper focuses on the massive colliding-wind binary HD 152248, which is the brightest X-ray source of the cluster. The campaign, with a total duration of 180 ks, was split into six separate observations, following the orbital motion of HD 152248. The X-ray flux from this system presents a clear, asymmetric modulation with the phase and ranges from 0.73 to 1.18 x 10(-12) erg s(-1) cm(-2) in the 0.5-10.0 keV energy band. The maximum of the emission is reached slightly after apastron. The EPIC spectra are quite soft, and peak around 0.8-0.9 keV. We characterize their shape using several combinations Of MEKAL models and power-law spectra and we detect significant spectral variability in the 0.5-2.5 keV energy band. We also perform 2D hydrodynamical simulations using different sets of parameters that closely reproduce the physical and orbital configuration of the HD 152248 system at the time of the six XMM-Newton pointings. This allows a direct confrontation of the model predictions with the constraints deduced from the X-ray observations of the system. We show that the observed variation of the flux can be explained by a variation of the X-ray emission from the colliding-wind zone, diluted by the softer X-ray contribution of the two O-type stars of the system. Our simulations also reveal that the interaction region of HD 152248 should be highly unstable, giving rise to shells of dense gas that are separated by low-density regions. Finally, we perform a search for short-term variability in the light curves of the system and we show that trends are present within several of the 30-ks exposures of our campaign. Further, most of these trends are in good agreement with the orbital motion and provide a direct constraint on the first-order derivative of the flux. In the same context, we also search for long-range correlations in the X-ray data of the system, but we only marginally detect them in the high-energy tail of the signal. [less ▲]

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See detailClient, mon cher Client ?
Van Caillie, Didier ULg

Article for general public (2004)

This short chronicle recalls how it's important that a firm, even small, do know exactly which are the costs really induced by servicing a client and the consequences on the gross margin realized with ... [more ▼]

This short chronicle recalls how it's important that a firm, even small, do know exactly which are the costs really induced by servicing a client and the consequences on the gross margin realized with this client. [less ▲]

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See detailNumerical and analytical investigations on composite sway frames
Demonceau, Jean-François ULg; Jaspart, Jean-Pierre ULg

in Modern Building Materials, Structures and Techniques (2004, May 19)

A modern design code for composite construction such as Eurocode 4 limits its scope to “non-sway buildings” with efficient bracing systems. Therefore, it gives mainly rules to analyse and to check ... [more ▼]

A modern design code for composite construction such as Eurocode 4 limits its scope to “non-sway buildings” with efficient bracing systems. Therefore, it gives mainly rules to analyse and to check structural elements like beams, columns, slabs and joints. However, in the last years, the construction of taller buildings and larger industrial halls without wind bracing systems is susceptible to make global instability a relevant failure mode, what is not yet covered by Eurocode 4. For three years, in the framework of a European research project funded by the European Community for Steel and Coal (ECSC), in which Liège University was deeply involved, intensive experimental, numerical and theoretical investigations have been carried out. The latter aimed at improving the knowledge in the field of sway composite frames and at developing appropriate design rules. The rotational behaviour of the beam-to-column composite joints is one of the key aspects of the problem to which a special attention has been paid. This paper presents numerical and analytical studies carried out at Liège University, as part of the above European project, with the objective to investigate the behaviour of 2D composite sway frames under static loading. Particular phenomena put into sight through different analyses are illustrated herein. [less ▲]

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See detailControlled free-radical polymerization products using new controlled agents
Vanhoorne, Pierre; Meyer, Rolf-Volker; Detrembleur, Christophe ULg et al

Patent (2004)

A process for the production of polymers by means of pseudo-living free-radical polymerization is disclosed. The process entails (i) reacting a polymerizable vinyl monomer with nitrogen monoxide and at ... [more ▼]

A process for the production of polymers by means of pseudo-living free-radical polymerization is disclosed. The process entails (i) reacting a polymerizable vinyl monomer with nitrogen monoxide and at least one initiator to prepare a free-radical intermediate product, and (ii) polymerizing the intermediate product optionally together with one or more additional monomers and/or with a free-radical initiator. [less ▲]

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