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See detailPhysical modelling of overbank flows with a groyne set on the floodplain
Peltier, Yann ULg

Doctoral thesis (2011)

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See detailPhysical modelling of water, fauna and flora: knowledge gaps, avenues for future research and infrastructural needs
ROBERT, THOMAS; JOHNSON, MATTHEW; FROSTICK, LYNNE et al

in Journal of Hydraulic Research (2014), 52

Physical modelling is a key tool for generating understanding of the complex interactions between aquatic organisms and hydraulics, which is important for management of aquatic environments under ... [more ▼]

Physical modelling is a key tool for generating understanding of the complex interactions between aquatic organisms and hydraulics, which is important for management of aquatic environments under environmental change and our ability to exploit ecosystem services. Many aspects of this field remain poorly understood and the use of physical models within eco-hydraulics requires advancement in methodological application and substantive understanding. This paper presents a review of the emergent themes from a workshop tasked with identifying the future infrastructure requirements of the next generation of eco-hydraulics researchers. The identified themes are: abiotic factors, adaptation, complexity and feedback, variation, and scale and scaling. The paper examines these themes and identifies how progress on each of them is key to existing and future eðorts to progress our knowledge of eco-hydraulic interactions. Examples are drawn from studies on biofilms, plants, and sessile and mobile fauna in shallow water fluvial and marine environments. Examples of research gaps and directions for educational, infrastructural and technological advance are also presented. [less ▲]

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See detailPhysical processes study in the transition zone of the Northwest African upwelling: climatological data analysis
Elmoussaoui, Abdellali; Djenidi, Salim ULg; Kostianoy, Andrey

(2003)

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See detailPhysical properties and transmission spectrum of the WASP-80 planetary system from multi-colour photometry
Mancini, L.; Southworth, J.; Ciceri, S. et al

in Astronomy and Astrophysics (2013), 1312

WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves of one transit event, obtained simultaneously using two defocussed ... [more ▼]

WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves of one transit event, obtained simultaneously using two defocussed telescopes. These data were taken through the Bessell I, Sloan griz and near-infrared JHK passbands. We use our data to search for opacity-induced changes in the planetary radius, but find that all values agree with each other. Our data are therefore consistent with a flat transmission spectrum to within the observational uncertainties. We also measure an activity index of the host star of log R'_HK=-4.495, meaning that WASP-80A shows strong chromospheric activity. The non-detection of starspots implies that, if they exist, they must be small and symmetrically distributed on the stellar surface. We model all available optical transit light curves to obtain improved physical properties and orbital ephemerides for the system. [less ▲]

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See detailPhysical properties at high magnetic fields in CeIn2.75Sn0.25
Ebihara, T.; Harrison, N.; Jaime, M. et al

in Journal of Magnetism & Magnetic Materials (2007), 310(2), 298-299

High magnetic field induces quantum criticality in CeIn3 with suppressing the Neel temperature. Estimated quantum critical. efield of CeIn3 is about 60T where the Neel temperature is suppressed to reach ... [more ▼]

High magnetic field induces quantum criticality in CeIn3 with suppressing the Neel temperature. Estimated quantum critical. efield of CeIn3 is about 60T where the Neel temperature is suppressed to reach absolute zero. The magnetic. field (60T) is too high to measure electrical resistivity or specific heat precisely. Sn doping to In site of CeIn3 reduces the Neel temperature. Reduction of Neel temperature indicates lower critical. field to facilitate investigation of electronic states at high magnetic. fields. Electrical resistivity and specific. c heat in CeIn2.Sn-85(0.25) were measured to map an H-T phase diagram. (c) 2006 Elsevier B. V. All rights reserved. [less ▲]

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See detailPhysical Properties of Particles of Ipratropium and Clenbuterol Generated by Equipment Suitable for the Inhalation of Drugs by Calves
Genicot, Bruno; Lapp, K.; Close, Roland et al

in Research in Veterinary Science (1995), 59(2), 164-167

When solutions of ipratropium and clenbuterol were atomised at 300 kPa and 450 kPa in equipment suitable for the inhalation of drugs by calves, the numbers, velocities and diameters of the particles ... [more ▼]

When solutions of ipratropium and clenbuterol were atomised at 300 kPa and 450 kPa in equipment suitable for the inhalation of drugs by calves, the numbers, velocities and diameters of the particles produced were similar. When the pressure was increased to 600 kPa more of the particles were less than 2 microns in diameter and fewer were more than 7 microns in diameter, the fractions of the total mass of the solution generated in these size ranges were similarly increased and decreased, and the velocities of the particles were increased. At any given pressure, the numbers of particles of different sizes, and the proportions of the total mass generated, were similar for the solutions of ipratropium and clenbuterol, but a solution of saline produced more particles with a diameter less than 3 microns. Particles from the solution of ipratropium had the highest velocity and particles from the solution of clenbuterol had the lowest velocity. [less ▲]

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See detailPhysical properties of silver nanowire networks: effects of percolation and thermal annealing
Langley, Daniel ULg; Lagrange, Mélanie; Giusti, Gael et al

Conference (2014)

Silver nanowire networks have recently been a heavily researched subject due to their potential use as transparent electrodes in solar cells or flat panel displays. Currently, the most commonly used ... [more ▼]

Silver nanowire networks have recently been a heavily researched subject due to their potential use as transparent electrodes in solar cells or flat panel displays. Currently, the most commonly used material for such applications (Tin-doped Indium oxide) suffers from two major drawbacks: indium scarcity and brittleness. However, metallic nanowire networks can be deposited by low cost deposition techniques and exhibit simultaneously very promising optical, electrical and electro-mechanical properties. To enhance these properties, nanowire density should be considered. For a given nanowire aspect ratio, lower nanowire densities result in higher optical transparency but demonstrate lower electrical conductivity. As the density of nanowires is increased the relationship is reversed, resulting in high electrical conductivity but low optical transparency. Numerical Montecarlo simulations on stick percolation shed light on the percolative nature of these 2D networks. Relations between simulation and experimental observations are discussed. We also show that thermal annealing can efficiently improve the electrical properties without significantly changing the optical response2. However, above a certain temperature threshold, morphological instabilities occur and induce a cancelling out of the beneficial effects. The physical mechanisms involved in thermal annealing of Ag nanowire networks are addressed as well as their effects on electro-optical properties. Finally the potential integration of Ag nanowire networks into devices is evaluated. [less ▲]

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See detailPhysical Properties of the 0.94-Day Period Transiting Planetary System WASP-18
Southworth, John; Hinse, T. C.; Dominik, M. et al

in Astrophysical Journal (2009), 707

We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we ... [more ▼]

We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we achieve a photometric precision of 0.47-0.83 mmag per observation over complete transit events. The data are analyzed using the JKTEBOP code and three different sets of stellar evolutionary models. We find the mass and radius of the planet to be M [SUB]b[/SUB] = 10.43 ± 0.30 ± 0.24 M [SUB]Jup[/SUB] and R [SUB]b[/SUB] = 1.165 ± 0.055 ± 0.014 R [SUB]Jup[/SUB] (statistical and systematic errors), respectively. The systematic errors in the orbital separation and the stellar and planetary masses, arising from the use of theoretical predictions, are of a similar size to the statistical errors and set a limit on our understanding of the WASP-18 system. We point out that seven of the nine known massive transiting planets (M [SUB]b[/SUB] > 3 M [SUB]Jup[/SUB]) have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less-massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios. Based on data collected by MiNDSTEp with the Danish 1.54  m telescope at the ESO La Silla Observatory. [less ▲]

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See detailPhysical properties, transmission and emission spectra of the WASP-19 planetary system from multi-colour photometry
Mancini, L.; Ciceri, S.; Chen, G. et al

in Monthly Notices of the Royal Astronomical Society (2013), 436

We present new ground-based, multi-colour, broad-band photometric measurements of the physical parameters, transmission and emission spectra of the transiting extrasolar planet WASP-19b. The measurements ... [more ▼]

We present new ground-based, multi-colour, broad-band photometric measurements of the physical parameters, transmission and emission spectra of the transiting extrasolar planet WASP-19b. The measurements are based on observations of eight transits and four occultations through a Gunn i filter using the 1.54-m Danish Telescope, 14 transits through an R[SUB]c[/SUB] filter at the Perth Exoplanet Survey Telescope (PEST) observatory and one transit observed simultaneously through four optical (Sloan g[SUP]'[/SUP], r[SUP]'[/SUP], i[SUP]'[/SUP], z[SUP]'[/SUP]) and three near-infrared (J, H, K) filters, using the Gamma Ray Burst Optical and Near-Infrared Detector (GROND) instrument on the MPG/ESO 2.2-m telescope. The GROND optical light curves have a point-to-point scatter around the best-fitting model between 0.52 and 0.65 mmag rms. We use these new data to measure refined physical parameters for the system. We find the planet to be more bloated (R[SUB]b[/SUB] = 1.410 ± 0.017R[SUB]Jup[/SUB]; M[SUB]b[/SUB] = 1.139 ± 0.030M[SUB]Jup[/SUB]) and the system to be twice as old as initially thought. We also used published and archived data sets to study the transit timings, which do not depart from a linear ephemeris. We detected an anomaly in the GROND transit light curve which is compatible with a spot on the photosphere of the parent star. The starspot position, size, spot contrast and temperature were established. Using our new and published measurements, we assembled the planet's transmission spectrum over the 370-2350 nm wavelength range and its emission spectrum over the 750-8000 nm range. By comparing these data to theoretical models we investigated the theoretically predicted variation of the apparent radius of WASP-19b as a function of wavelength and studied the composition and thermal structure of its atmosphere. We conclude that: (i) there is no evidence for strong optical absorbers at low pressure, supporting the common idea that the planet's atmosphere lacks a dayside inversion; (ii) the temperature of the planet is not homogenized, because the high warming of its dayside causes the planet to be more efficient in re-radiating than redistributing energy to the night side; (iii) the planet seems to be outside of any current classification scheme. [less ▲]

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See detailPhysical Therapists’ Knowledge, Attitudes, and Beliefs about Physical Activity: A Prerequisite to their Role in Physical Activity Promotion?
Mouton, Alexandre ULg; MUGNIER, Benoît ULg; Demoulin, Christophe ULg et al

in Journal of Physical Therapy Education (2014), 28(3), 120-127

Background. The promotion of physical activity (PA) is widely recognized as a major component of the prevention and management of several chronic diseases. As experts in human movement, physical ... [more ▼]

Background. The promotion of physical activity (PA) is widely recognized as a major component of the prevention and management of several chronic diseases. As experts in human movement, physical therapists (PTs) are logical agents for the promotion of PA. Nevertheless, to date only few studies have investigated factors that influence PA promotion. Objectives. This study aimed to analyze the relationships between physical therapist knowledge, attitudes, and beliefs about PA, and their own selfreported PA promotion. Design. A sample of 185 PTs (male = 102) completed a cross-sectional survey through an online questionnaire. It included 25 multiple choice, Likert scale, and open-ended questions related to (1) personal characteristics, (2) knowledge, attitudes, and beliefs about PA, and (3) self-reported PA promotion by PTs. A deductive and inductive content analysis of the openended questions was also performed. Results. The questionnaire revealed that 99% of PTs agreed (n = 30) or completely agreed (n = 154) with the fact that they have to contribute to PA promotion in their patients. Significant correlations were found between physical therapist knowledge of the definition of PA, the benefits of PA, and their self-reported PA promotion (0.251, P < .01 and 0.180, P < .05, respectively). Additional multivariate analysis of the predictors of the self-reported PA promotion exposed significant univariate effects of knowledge, attitudes, and beliefs about PA (P < .01). Conclusion. Although the role of PTs in PA promotion seems evident, this survey underlines important misconceptions about PA within this group of health care professionals. Significant relationships between physical therapist knowledge, attitudes, and beliefs about PA and self reported promotion of PA highlight the need for physical therapist education programs to emphasize teaching the fundamentals of PA. [less ▲]

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See detailPhysically based and spatially distributed modeling of floods events: The "Faitou" concept
Dubois, Jérôme; Pirotton, Michel ULg; Schleiss, Anton

in International Symposium on Flood Defence (2000)

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See detailPhysically Based Groundwater Vulnerability Assessment Using Sensitivity Analysis Methods
Beaujean, Jean ULg; Lemieux, Jean-Michel; Dassargues, Alain ULg et al

in Ground Water (2013), 52(6), 864-874

A general physically based method is presented to assess the vulnerability of groundwater to external pressures by numerical simulation of groundwater flow. The concept of groundwater vulnerability ... [more ▼]

A general physically based method is presented to assess the vulnerability of groundwater to external pressures by numerical simulation of groundwater flow. The concept of groundwater vulnerability assessment considered here is based on the calculation of sensitivity coefficients for a user-defined groundwater state for which we propose several physically based indicators. Two sensitivity analysis methods are presented: the sensitivity equation method and the adjoint operator method. We show how careful selection of a method can significantly minimize the computational effort. An illustration of the general methodology is presented for the Herten aquifer analog (Germany). This application to a simple, yet insightful, case demonstrates the potential use of this general and physically based vulnerability assessment method to complex aquifers. [less ▲]

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See detailA physically motivated pixel-based model for background subtraction in 3D images
Braham, Marc ULg; Lejeune, Antoine ULg; Van Droogenbroeck, Marc ULg

in International Conference on 3D Imaging (IC3D) (2014, December)

This paper proposes a new pixel-based background subtraction technique, applicable to range images, to detect motion. Our method exploits the physical meaning of depth information, which leads to an ... [more ▼]

This paper proposes a new pixel-based background subtraction technique, applicable to range images, to detect motion. Our method exploits the physical meaning of depth information, which leads to an improved background/foreground segmentation and the instantaneous suppression of ghosts that would appear on color images. In particular, our technique considers certain characteristics of depth measurements, such as failures for certain pixels or the non-uniformity of the spatial distribution of noise in range images, to build an improved pixel-based background model. Experiments show that incorporating specificities related to depth measurements allows us to propose a method whose performance is increased with respect to other state-of-the-art methods. [less ▲]

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See detailA Physically-Based Approach to predict input hydrographs in managed reservoirs
Pirotton, Michel ULg

in Berga, L. (Ed.) New trends and Guidelines on Dam Safety (1998)

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See detailPhysically-based groundwater vulnerability assessment for groundwater protection and land-use management
Popescu, Ileana-Cristina; Brouyère, Serge ULg; Derouane, Johan et al

Poster (2010, April 22)

Numerous groundwater vulnerability and risk mapping techniques have been developed taking into consideration a variable number of factors. Most common techniques produce maps of indexes based on a ... [more ▼]

Numerous groundwater vulnerability and risk mapping techniques have been developed taking into consideration a variable number of factors. Most common techniques produce maps of indexes based on a relatively empirical combination of weighted factors reflecting the protective effect of underground formations overlying the groundwater resource. The limitation of such methods is related to their use of a qualitative definition of groundwater vulnerability, as opposed to a definition based on a quantitative description of contaminant migration. A physically-based point of view and definition of the vulnerability is proposed and based on three factors describing a pollution event, which are the contaminant transfer time from the hazard location to the 'target', the contamination duration at the 'target' and the level of contaminant concentration reached at the 'target'. This concept allows a clear distinction between conventional aspects and physically-based results in the building of a final vulnerability indicator. This methodology has the further advantage to consider the possible impact of runoff conditions occurring at the land surface and possibly leading to lateral contamination of groundwater through downstream preferential infiltration features, such as karstic features. Practically, this method needs to describe and simulate the pollutant migration in the unsaturated zone and possibly in the saturated zone in order to assess the breakthrough curve at the 'target'. Preliminary application is illustrated on a case-study located in a Néblon limestone basin in Belgium, one of the main groundwater resources for the city of Liège in the Meuse basin. Perspectives are proposed towards a generalisation of the vulnerability concept for risk assessment within a pressure - state - impact framework. [less ▲]

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See detailPhysician Induced Demand for C-Sections: Does the Convenience Incentive Matter?
Lefevre, Mélanie ULg

Scientific conference (2014, June)

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See detailPhysician induced demand for C-sections: does the convenience incentive matter?
Lefevre, Mélanie ULg

E-print/Working paper (2014)

This paper investigates whether physicians induce demand for C-sections in the days preceding leisure periods. I reject that doctors are meaningfully increasing the number of primary cesareans to ... [more ▼]

This paper investigates whether physicians induce demand for C-sections in the days preceding leisure periods. I reject that doctors are meaningfully increasing the number of primary cesareans to accommodate their own preferences for control of deliveries around holiday Mondays. Using a sample of more than 1,300,000 deliveries, I can estimate that the induced demand due to convenience is close to zero. A small signi cant e ect is found for women having had a previous C-section. While I replicate previous results of lower C-section rates on leisure periods, I show that they are due to the way doctors schedule planned cesareans rather than to an induced demand for reason of physicians' convenience. If induced demand occurs, the decision takes place in the labor room and is not planned in advance. [less ▲]

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See detailPhysician Induced Demand for C-Sections: Does the Convenience Incentive Matter?
Lefevre, Mélanie ULg

E-print/Working paper (2013)

This paper investigates whether physicians induce demand for C-sections in the days preceding leisure periods. I reject that doctors are meaningfully increasing the number of cesareans to accommodate ... [more ▼]

This paper investigates whether physicians induce demand for C-sections in the days preceding leisure periods. I reject that doctors are meaningfully increasing the number of cesareans to accommodate their own preferences for control of deliveries around holiday Mondays. Using a sample of more than 1,300,000 deliveries, I can precisely estimate that the induced demand due to convenience is close to zero. While I replicate previous results of lower C-section rates on leisure periods, I show that they are due to the way doctors schedule planned cesareans rather than to an induced demand for reason of physicians' convenience. [less ▲]

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