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See detailCharacterisation of thermophysical properties of semi-solid steels for thixoforming
Lecomte-Beckers, Jacqueline ULg; Rassili, Ahmed ULg; Carton, Marc ULg et al

in Proceedings of the 8th International Conference on Semi-Solid Processing of Alloys and Composites (S2P) (2004)

Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is ... [more ▼]

Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is appropriate solidus-liquidus interval. The wider the solidification interval, the wider the processing window. This study is related to the experimental determination of this critical parameter on eight different steel compositions. This parameter was obtained using Differential Scanning Calorimetry. This technique allows to obtain the solid fraction versus temperature. The paper also presents the results of thermophysical properties determination such as thermal diffusivity, heat capacity and thermal conductivity. These properties were measured from room temperature to semi-solid state in one particular steel. The thermal diffusivity was measured using the Laser Flash method and the heat capacity using a DSC calorimeter. The thermal conductivity was obtained by calculation knowing the thermal dilatation measured with a dilatometer. All these measurements were performed for temperatures up to the liquidus. These parameters are difficult to measure but they are important to determine for the conductive heating phase of a semi-solid forming (SSM) process. [less ▲]

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See detailCharacterisation of TRIP-assisted steel by atomic force microscopy and OIM
Ros-Yanez, Tanya; Houbaert, Yvan; Petrov, Roumen et al

in De Cooman, Bruno C. (Ed.) Proceedings of the International Conference on TRIP-Aided High-Strength Ferrous Alloys (2002, June)

TRIP-assisted steel has a complicated microstructure, obtained through well designed heat treatments and consisting of different phases, mainly ferrite, retained austenite, bainite and martensite. The ... [more ▼]

TRIP-assisted steel has a complicated microstructure, obtained through well designed heat treatments and consisting of different phases, mainly ferrite, retained austenite, bainite and martensite. The drastic influence of microstructure on physical and mechanical properties makes metallographic examination a necessity for property understanding and enhancement. A fairly simple tint etching procedure (LePera method) using light microscopy and SEM observation ensures the distinction of ferrite, bainite and retained austenite/martensite grains. Nevertheless, the etching is not selective enough to allow a distinction between retained austenite and martensite. Atomic force microscopy was used for the phase identification and characterisation of this kind of steel. A series of tests was performed using AFM-contact mode and magnetic force microscopy in C-Mn-Si and C-Mn-Al TRIP-assisted steel after intercritical annealing followed by ageing, After ageing, some samples were tempered in order to make metallographic observation easier. It has been possible to identify the different phases and their topographic characteristics and to study their morphology using AFM. Orientation imaging microscopy was used to calibrate the observations done with AFM, distinguishing between bcc- and fcc-zones and quantify the retained austenite. [less ▲]

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See detailCharacterising and Exploiting Workloads of Highly Interactive Video-on-Demand
Brampton, Andrew; MacQuire, Andrew; Fry, Michael et al

in Multimedia Systems (2009)

This paper presents a detailed character- isation of user behaviour for a series of interactive video experiments over a 12 month period, in which we served popular sporting and musical content. In ad ... [more ▼]

This paper presents a detailed character- isation of user behaviour for a series of interactive video experiments over a 12 month period, in which we served popular sporting and musical content. In ad- dition to generic VCR-like features, our custom-built Video-on-Demand application provides advanced inter- activity features such as bookmarking. The dramatic impact of such functionality on how users consume con- tent is studied and analysed. We discuss in detail how this user behaviour can be exploited by content dis- tributors to improve user experience. Speci cally, we study how simple dynamic bookmark placement and interactivity-aware content pre-fetching and replication can reduce the impact of highly interactive media on CDN performance. [less ▲]

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See detailCharacterising the spectra of spray droplets on three artificial targets using image analysis.
Degre, Aurore ULg; Mostade, Olivier; Huyghebaert, Bruno et al

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (2000), 65(2b),

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See detailCharacterising urban morphology with spectral unmixing and spatial metrics: a case study on Dublin
Canters, Frank; Van de Voorde, Tim; Binard, Marc ULg et al

in Proceedings of the 24th International Cartographic Conference (ICC 2009), (2009)

In today’s urbanising world, effective urban management and planning strategies are needed to temper the impact of urban change processes on the natural and human environment. To develop and monitor such ... [more ▼]

In today’s urbanising world, effective urban management and planning strategies are needed to temper the impact of urban change processes on the natural and human environment. To develop and monitor such strategies, and to assess their spatial impact, analysing changes in urban structure is essential. Data from earth observation satellites provide regular information on urban development and, as such, may contribute to the mapping and monitoring of cities and the modelling of urban dynamics. Especially images of medium resolution (Landsat, SPOT, …), which are cheap, widely available and often part of extensive historic archives, offer a wealth of information that may be useful for urban monitoring purposes. The lower resolution of this type of imagery, however, hampers the study of urban morphology and change processes at a more detailed, intra-urban level. Spectral unmixing approaches, which allow characterising land-cover distribution at sub-pixel level, may partly compensate for this lack of spatial detail, and may render medium-resolution imagery more useful for urban studies. The main research question addressed in this paper is how medium-resolution imagery could be used to describe urban morphology, by combining spectral unmixing approaches with spatial metrics. Spatial metrics derived from satellite imagery may be useful to quantify structural characteristics of expanding cities, and may provide indications of functional land use. In this study, we develop a set of urban metrics for use on continuous sealed surface data produced by sub-pixel classification of Landsat ETM+ imagery. Two sub-pixel classification approaches are examined for that purpose. In a first approach, we use a linear spectral mixture model with a vegetation and a non-vegetation endmember to deconvolve each pixel’s spectrum into fractional abundances of the two end member spectra, which are determined by visualising mixture space with principal component analysis. In a second approach, we use a linear regression model to estimate the proportion of vegetation cover within each Landsat pixel. In both approaches, an urban mask is used to indicate pixels belonging to urban land cover. Only pixels within the urban mask are subjected to sub-pixel classification. We hereby assume that the urban area does not contain bare soil and that the area of a pixel not covered by vegetation fully consists of sealed surface cover. The resulting sealed surface proportion map is then used to characterise urban morphology and land use by means of the shape of the cumulative frequency distribution of the estimated sealed surface fractions within a building block. A transformed logistic function is fitted to this distribution with a least-squares approach to obtain function parameters that are used as variables in a supervised classification approach, together with spatially explicit metrics (spatial variance and Moran’s I). Our study demonstrates that images from medium resolution sensors can be used to characterise intra-urban morphology, and that the structure of a building block as described by the proposed metrics gives an indication of its membership to certain morphological/functional urban classes. In future research we will incorporate socio-economic data in the metric analysis to further improve the distinction of urban land-use categories. The spatial metrics approach developed in this study will be used in experiments to improve the calibration of the MOLAND urban growth model, which is currently calibrated with historical land-use maps available for approximately 10-year intervals. [less ▲]

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See detailCharacterising User Interactivity for Sports Video-on-Demand
Brampton, A.; MacQuire, A.; Rai, I. et al

in NOSSDAV Proceedings (2007, June)

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See detailThe characteristic features of auditory verbal hallucinations in clinical and nonclinical groups: state-of-the-art overview and future directions
Laroi, Frank ULg; Sommer, I.; Blom, J. D. et al

in Schizophrenia Bulletin (2012), 38

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See detailCharacteristics and age of an uplift signal in the Biga Peninsula (NW Turkey) from a mix of geomorphic indices
Demoulin, Alain ULg; Bayer Altin, Turkan; Beckers, Arnaud ULg

Poster (2013, April 11)

Situated in the area where the western end of the North Anatolian Fault Zone meets the extensional domain of the North Aegean Sea, the Kazdag Mountain range (Biga Peninsula, NW Turkey) is known to have ... [more ▼]

Situated in the area where the western end of the North Anatolian Fault Zone meets the extensional domain of the North Aegean Sea, the Kazdag Mountain range (Biga Peninsula, NW Turkey) is known to have undergone Plio-Quaternary uplift. However, no detailed chronology of this presumably ongoing uplift phase was so far available. In order to obtain a first-order estimate of the time of the last tectonic perturbation (uplift rate change) in the region, we performed a morphometric study of the fluvial landscape at the scale of the Biga Peninsula, coupling the recently developed R/SR analysis of the drainage network with concavity and steepness measures of a set of 29 rivers of all sizes. Defined as the ratio of two-by-two differences between hypsometric integrals describing respectively a catchment’s topography, its drainage network "composite profile" and the trunk stream profile, the R metric is a measure of the catchment’s incision response to a relative base level lowering. The SR index is then simply the slope of the regional relation R = f(ln A), a feature characteristic of the time elapsed since uplift caused an erosion wave to propagate in the drainage system. We obtained a SR value of 0.324±0.035 that, according to the t = f(SR) relation established by Demoulin (2012), yields an age range of 0.54-1.29 Ma and a most probable value of 0.82 Ma for the time of the last uplift signal in the Biga Peninsula. We also carried out an analysis of knickpoint migration in a subset of rivers, modelling their propagation by the stream power law under different assumed ages so as to compare the obtained values of the K coefficient with values mentioned in the literature. The positive results of this analysis, yielding realistic K values for ages around 0.8 Ma, lend independent support to our morphometric estimate of the uplift time, moreover corroborated by published observations suggesting basin inversion of the Bayramiç and Çanakkale depressions at the same epoch. We relate this episode of increased uplift rate to the early-to-mid Pleistocene tectonic transition identified in the Eastern Mediterranean realm by Schattner (2010) and marked by a brief compressional episode. Finally, while the dependence of river profile concavity on basin size confirms that the landscape of the peninsula is still in a transient state, the spatial distribution of profile steepness values characterized by higher values for streams flowing down from the Kazdag massif shows that the latter undergoes higher uplift rates than the rest of the peninsula. This indicates that, after the regional Middle Pleistocene episode of accelerated uplift had come to an end, a local component of uplift persisted associated with either transpressive conditions along SW-trending segments of the North Anatolian Shear Zone or normal faulting along the southern border of the massif. References Demoulin A., 2012. Morphometric dating of the fluvial landscape response to a tectonic perturbation. Geoph. Res. Lett. 39, L15402, doi:10.1029/2012GL052201. Schattner U., 2010. What triggered the early-to-mid Pleistocene tectonic transition across the entire eastern Mediterranean? Earth Planet. Sci. Lett. 289, 539-548. [less ▲]

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See detailCharacteristics and Cause of Localized Auroral Uv Emission At High Latitude
Frey, H. U.; Mende, S. B.; Immel, T. J. et al

in EGS XXVII General Assembly, Nice, 21-26 April 2002 (2002)

The FUV instrument on IMAGE frequently observes localized ultraviolet emission at high latitudes, poleward of the general auroral oval. These localized emissions occur during northward IMF conditions and ... [more ▼]

The FUV instrument on IMAGE frequently observes localized ultraviolet emission at high latitudes, poleward of the general auroral oval. These localized emissions occur during northward IMF conditions and there are two different types of them. One type is especially distinct in the observations of Doppler shifted Lyman alpha emission from proton precipitation. This type occurs during high solar wind dynamic pressure. We interpret this emission as the optical signature of proton precipitation into the cusp after lobe reconnection at the magnetopause. The second type of localized emission is distinct in the wide-band (WIC) and oxygen (SI13) images, but is absent in the proton images. This emission occurs during positive IMF By, but very low solar wind density and dynamic pressure. We interpret this emission as the optical signature of electron acceleration in the upward part of a field aligned current circuit after reconnection. [less ▲]

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See detailCharacteristics and ceramic properties of clayey materials from Amezmiz region (Western High Atlas, Morocco)
Daoudi, Lahcen; El Boudour El Idrissi, Hicham ULg; Saadi, Latifa et al

in Applied Clay Science (2014)

Five clayey materials from two quarries located in the Amezmiz region (Morocco) were sampled and investigated for their physical, chemical, mineralogical and thermal characteristics to evaluate their ... [more ▼]

Five clayey materials from two quarries located in the Amezmiz region (Morocco) were sampled and investigated for their physical, chemical, mineralogical and thermal characteristics to evaluate their potential suitability as raw materials in various ceramic applications. Physical properties were identified by particle size distribution, consistency limits and total organic content. Chemical, mineralogical, and thermal properties were investigated by XRF, XRD, and TG/DTA techniques, respectively. A common raw material in pottery manufacturing of Morocco was used as reference sample (REF). Results show that the main oxides in the samples were SiO2, Al2O3, and Fe2O3, whereas the other oxides were present only in small quantities. Quartz, illite and vermiculite were present as dominant mineral phases with minor kaolinite, calcite and smectite. The results showed that three of the studied clayey materials have adequate characteristics for the production of structural ceramics. However, for the two other clays it is necessary to add more plastic clays to enhance the workability. [less ▲]

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See detailCharacteristics and determinants of the dipping phenomenon
Saint-Remy, Annie ULg; Moonen, martial; Rorive, Georges ULg

in Journal of Hypertension (Supplement) (1996), 14(1), 260

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See detailCharacteristics and effects of organic matter on Belgian loamy soils : a reference system
Bock, Laurent ULg; Ducat, Nathalie; Roisin, Vincent et al

in Neeteson, J.J.; Hassink, J. (Eds.) Nitrogen mineralization in agricultural soils (1994)

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See detailCharacteristics and efficiency of some livestock production systems in the Red River Delta: Case study in Cam Giang district, Hai Duong province
Han Quang, Hanh ULg

in Proceedings of the 13th Animal Science Congress of the Asian-Australasian Association of Animal Production Societies (2008, September 22)

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See detailCharacteristics and evolution of hantavirus infection in Liège Area (Belgium)
Krzesinski, Jean-Marie ULg; parotte, Marie-Christine; Vanden velde, Christian

Poster (2011, June 24)

Hantavirus is a zoonosis transmitted by rodents responsible in Europe for Hemorrhagic fever with acute renal syndrome (called nephropathia epidemica or NE). Hantavirus epidemics were increased in the ... [more ▼]

Hantavirus is a zoonosis transmitted by rodents responsible in Europe for Hemorrhagic fever with acute renal syndrome (called nephropathia epidemica or NE). Hantavirus epidemics were increased in the recent years in the South part of Belgium. After acute illness, the question could be about its evolution. [less ▲]

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See detailCharacteristics and expectations of patients with erectile dysfunction: results of the SCORED
Claes, Hubert; Opsomer, Reinier; Andrianne, Robert ULg et al

in International Journal of Impotence Research: The Journal of Sexual Medicine (2008)

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See detailCharacteristics and expectations of patients with erectile dysfunction: results of the SCORED study.
Claes, Hubert; Opsomer, R.-J.; Andrianne, Robert ULg et al

in International Journal of Impotence Research : Official Journal of the International Society for Impotence Research (2008), 20(4), 418-24

In an observational study in men with erectile dysfunction (ED) consulting a general practitioner (GP) or urologist in Belgium, demographics, ED characteristics (including erection hardness score), co ... [more ▼]

In an observational study in men with erectile dysfunction (ED) consulting a general practitioner (GP) or urologist in Belgium, demographics, ED characteristics (including erection hardness score), co-morbidities and treatment expectations were evaluated using a structured questionnaire. In total, 341 GPs and 41 urologists recruited 1492 patients. Most (74%) were untreated and 25% had ED for >3 years. Considering PDE5 inhibitors, erection hardness (89%) and maintenance (92%) were considered 'very important' by most patients. Only 18% of physicians initiated discussion about ED, despite 41% of patients having >or=3 known risk factors. The questionnaire was considered helpful by 81% of GPs and 83% of their patients. Overall, patients are under-diagnosed, and physicians are reluctant to ask about ED. A questionnaire including erection hardness score is useful to facilitate discussion about ED in general practice. Erection hardness and maintenance are more important to patients as compared to fast onset or long duration of action. [less ▲]

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See detailCharacteristics and implementation of Hybrid Fire Testing (HFT)
Sauca, Ana ULg; Gernay, Thomas ULg; Robert, Fabienne et al

Conference (2015, June 18)

This presentation is dedicated to real time hybrid testing of building members subjected to the action of fire. It will be shown why, whereas pseudo-dynamic testing is possible in other fields, real time ... [more ▼]

This presentation is dedicated to real time hybrid testing of building members subjected to the action of fire. It will be shown why, whereas pseudo-dynamic testing is possible in other fields, real time hybrid testing is the only possible option for the evaluation of fire performance (except, perhaps, for pure metallic unprotected structures). For some structures subjected to fire, the load bearing mechanism in the physical component is completely modified during the test and this modification can take place within a very short period of time. Because of that, the computational demand can be very challenging if the simulated element is simulated in a fully nonlinear computer model, especially if the thermal problem (temperature distribution in the structure) and the mechanical problem have both to be solved within each time step. In order to avoid these difficulties, a possible solution may be to calculate the stiffness matrix that dictates the reaction of the simulated element on the tested element before the test. This matrix can be constant or vary as a function of the displacements measured at the interface during the test. This procedure is very robust but it also has some shortcomings and limitations. The main topic of this paper is the discussion of the advantages and limitations of this procedure applied to hybrid fire testing. A series of three tests which is now under preparation to be performed in the furnace PROMETHEE of CERIB, in France, will also be described in this respect. Preliminary results will be presented if some or all of the tests have been performed at the date of the conference. [less ▲]

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See detailCharacteristics associated with early (less than or equal to 3 months) versus late (greater than 3 months to less than or equal to 3 years) mortality after acute myocardial infarction.
Pierard, Luc ULg; Chapelle, Jean ULg; Albert, Adelin ULg et al

in American Journal of Cardiology (1989), 64(5), 315-8

To define the independent variables predictive of early versus late mortality after acute myocardial infarction (AMI), 420 consecutive patients were studied and divided into 3 groups: the 45 patients who ... [more ▼]

To define the independent variables predictive of early versus late mortality after acute myocardial infarction (AMI), 420 consecutive patients were studied and divided into 3 groups: the 45 patients who died within the initial 3 months (group 1), the 45 patients who died greater than 3 months and less than or equal to 3 years after AMI (group 2) and the 330 greater than 3-year survivors (group 3). The stepwise logistic discrimination method was applied to clinical and laboratory variables recorded during hospitalization to distinguish among the 3 groups. Six independent variables were found to be predictive of early mortality: left ventricular function score (chi-square 26.2; p less than 0.00001), ventricular fibrillation (chi-square 9.3; p = 0.002), bundle branch block (chi-square 9.0; p = 0.003), history of previous AMI (chi-square 8.7; p = 0.003), age (chi-square 5.8; p = 0.02) and atrioventricular block (chi-square 3.8; p = 0.05). Three independent variables were found predictive of late mortality: age (chi-square 13.8; p = 0.0002), anterior location of the AMI (chi-square 4.0; p = 0.04) and a low peak creatine kinase-MB level (chi-square 3.8; p = 0.05). Only 2 variables were able to distinguish between early and late nonsurvivors: peak creatine kinase-MB level (chi-square 8.7; p = 0.003) and ventricular fibrillation (chi-square 4.6; p = 0.03). Thus, the sets of independent risk factors for early and late mortality after AMI are substantially different--suggesting that differing mechanisms are responsible for outcome. [less ▲]

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See detailCharacteristics of adolescent attempts to manage overweight
Grignard, Sophie ULg; Bourguignon, Jean-Pierre ULg; Born, Michel ULg et al

in Patient Education & Counseling (2003), 51(2), 183-189

This study evaluates the actions taken by obese adolescents in an attempt to lose weight in relation to changes in weight. Particular emphasis is put on the context surrounding the management process ... [more ▼]

This study evaluates the actions taken by obese adolescents in an attempt to lose weight in relation to changes in weight. Particular emphasis is put on the context surrounding the management process. Thirty one obese adolescents aged 14-18 participated in this study. The adolescents answered a written questionnaire, took a body-size dissatisfaction test and were interviewed. Their family physicians were interviewed by telephone. Quantitative data concerned changes in weight and body-size dissatisfaction scores. Qualitative analysis included cases analyses and building up of synthesis variables. Loss of weight is linked with continuity of management attempts as well as with medical follow-up. The most frequent management attempt is diet. Self-image is correlated with weight. The exclusive emphasis put on diet is discussed in relation to the importance of more psychosocial factors such as self-image, denial and attraction to discontinuity. Some recommendations for the management of overweight adolescents are then outlined. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved. [less ▲]

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