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See detailDetection of wheat root and straw in soil by use of Near Infrared hyperspectral imaging system and Partial Least Square discriminant analysis
Eylenbosch, Damien ULg; Fernández Pierna, Juan Antonio; Baeten, Vincent et al

Poster (2014, August 26)

Monitoring of root systems development and crop residues decomposition is only possible if these constituents can be discriminated from soil and quantified. In this work, Near Infrared (NIR) combined with ... [more ▼]

Monitoring of root systems development and crop residues decomposition is only possible if these constituents can be discriminated from soil and quantified. In this work, Near Infrared (NIR) combined with Hyperspectral Imaging (HSI) and Partial Least Square Discriminant Analysis (PLS-DA) is proposed as a new rapid and reliable method to discriminate soil, roots and straws. NIR-HSI provides simultaneously spectral and spatial information and PLS-DA allows discrimination between classes based on spectra of each pixel linked to chemical nature of sample constituents on the image. [less ▲]

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See detail“Latin American women in the global city of Brussels, defying their disadvantageous gendered positions through the construction of Transnational Artistic Careers.”
Vivas Romero, Maria ULg

Scientific conference (2014, August 26)

The life goal of constructing Transnational Artistic Careers might open up transnational opportunities for some migrant women who wish to participate in today’s global cities cultural domains. This paper ... [more ▼]

The life goal of constructing Transnational Artistic Careers might open up transnational opportunities for some migrant women who wish to participate in today’s global cities cultural domains. This paper is based on my first observations in the field as a PhD student through, which I encountered complex dynamics of Latin American and Gender identities constructions, both among my participants and myself. Therefore, drawing from a transnational and cosmopolitan practices perspectives, through this paper I refer to Transnational Artistic Careers that served the women invoked in my analysis, to develop cosmopolitan skills and competencies by which they develop multiple forms of identification. These competencies I will argue served these women as a tool to find recognition as well as to express, a sense of belonging that extended beyond ethnic categorizations deployed by more hegemonic perspectives. These women described themselves as the entrepreneurs of their own careers, which later helped them to engage in Cosmopolitan Sociabilities that ultimately served them to develop alternative representations of how they ultimately wanted to be known by “others”. By aiming to discover different forms of Transnational Artistic Careers and Cosmopolitan Sociabilities this paper, focuses on the agency by which these women contested, resisted and empowered themselves against racialized, and ethnicized global hierarchies of power. [less ▲]

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See detailIncreasing the efficiency of Organic Rankine Cycle Technology by means of Multivariable Predictive Control
Hernandez Naranjo, Jairo Andrés ULg; Desideri, Adriano ULg; Ionescu, Clara et al

Conference (2014, August 25)

The Organic Rankine Cycle (ORC) technology has become very popular, as it is extremely suitable for waste heat recovery from low-grade heat sources. As the ORC system is a strongly coupled nonlinear ... [more ▼]

The Organic Rankine Cycle (ORC) technology has become very popular, as it is extremely suitable for waste heat recovery from low-grade heat sources. As the ORC system is a strongly coupled nonlinear multiple-input multiple-output (MIMO) process, conventional control strategies (e.g. PID) may not achieve satisfactory results. In this contribution our focus is on the accurate regulation of the superheating, in order to increase the e fficiency of the cycle and to avoid the formation of liquid droplets that could damage the expander. To this end, a multivariable Model Predictive Control (MPC) strategy is proposed, its performance is compared to the one of PI controllers for the case of variable waste-heat source profi les. [less ▲]

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See detailCreation of universal MIR calibration by standardization of milk spectra: example of fatty acids
Grelet, Clément; Fernandez Pierna, Juan; Soyeurt, Hélène ULg et al

Poster (2014, August 25)

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Peer Reviewed
See detailmodelling heat and mass transfer during convective drying of a building material
Kahlerras, Loubna ULg

Conference (2014, August 24)

The purpose of this study is to characterize experimentally the behaviour of a cement mortar during its convective drying. The work presented here focuses on mortars with water-to cement ratios (w/C) of 0 ... [more ▼]

The purpose of this study is to characterize experimentally the behaviour of a cement mortar during its convective drying. The work presented here focuses on mortars with water-to cement ratios (w/C) of 0, 5. The drying tests are realized in a convective dryer designed for the drying of small samples (0 - 8g). Experiences are realized with different conditions of drying air temperature (60, 90 and 130 °C) and velocity (2, 3 and 5 m/s) the results show the influence of temperature and velocity on drying curve. Mathematical models have been used for the description of drying curves. The exponential mathematical model seems the most adequate to describe the drying curves of cement mortars, with correlation coefficients changing with the air temperature and velocity and close to unity. The convective mass and heat transfer coefficients are determined from the experimental data. The results showed that both mass and heat transfer coefficients were affected by the air temperature and velocity. The convective mass transfer coefficient changed from 0.0232m/s at V=2m/s to 0.045m/s at V=5m/s, and from 0.055 m/s at 60°c to 0.023 at 130°c. Heat transfer coefficient changed from 14.767 w/m2°c at V=2m/s to 28.64 w/m2°c at V=5m/s and from 7.71 at 60° c to 14.77 at 130°c The temperature dependency of the two coefficients was expressed using an Arrhenius-type equation and related parameters were deduced [less ▲]

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See detailExperimental study of the drying kinetic of mortar
Kahlerras, Loubna ULg

Conference (2014, August 24)

This work reports the results of an experimental study concerning on one hand the influence of water-to cement ratios (W/C), and the role of aggregates on the other hand on the drying kinetics of cement ... [more ▼]

This work reports the results of an experimental study concerning on one hand the influence of water-to cement ratios (W/C), and the role of aggregates on the other hand on the drying kinetics of cement pastes during thermal drying. Three types of cement pastes were realized and studied; cement pastes with ratios W/C 0.4, W/C 0.5 and mortar with ratio W/C 0.5. These tries present the advantage to reproduce the natural conditions met in the problems of interaction atmosphere and material. Cylindrical samples of cement of size (17 X 13) mm are dried in a convective dryer. The sample is continuously weighed during the drying test and its mass is recorded every 60 s, in the purpose to obtain the drying curves. The results show that the increase of the W/C ratio leads to an increase of the drying rate due to the increase of the initial porosity. The effect of the introduction of aggregates is observable by the comparison of the drying curve obtained for the mortar and the cement pastes. The results show a decrease of the drying kinetics with mortars. The results also show that the air drying temperature has a large impact on the drying process, increasing the temperature leading to significant drying time reduction. The Effective diffusion coefficient is calculated by comparison between the experimental results and the analytical solution of Fick’s equation written for a finite medium. [less ▲]

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See detailAge-dependent and age-independent effects of testosterone in male quail
Cornil, Charlotte ULg; Schmit, Mélanie; de Bournonville, Catherine ULg et al

in General and Comparative Endocrinology (2014), 208C

Various studies in rodents recently concluded that puberty should be considered as a second period of organization of brain and behavior and that action of sex steroids at that time is long lasting and ... [more ▼]

Various studies in rodents recently concluded that puberty should be considered as a second period of organization of brain and behavior and that action of sex steroids at that time is long lasting and possibly permanent. We tested this notion in male Japanese quail that had been castrated before 3 weeks post- hatch by analyzing whether a similar treatment with exogenous testosterone initiated at 3, 5 or 7 weeks post-hatch has a differential influence on the development of testosterone-dependent morphological, behavioral and neural characteristics that are known to be sexually differentiated. The growth of the androgen-dependent cloacal gland was significantly faster when testosterone treatment was initiated later in life indicating that the target tissue is not ready to fully respond to androgens at 3 weeks post- hatch. The three groups of birds nevertheless developed a gland of the same size typical of intact sexually mature birds. When adults, all birds expressed copulatory behavior with the same frequencies and laten- cies and they displayed the same level of aromatase activity and of vasotocinergic innervation in the pre- optic area as gonadally intact males despite the fact that they had been treated with testosterone for different durations starting at different ages. Surprisingly, the frequency of cloacal sphincter contractions, a measure of appetitive sexual behavior, was significantly higher when testosterone treatment had been initiated later. Together these data provide no clear evidence for an organizational action of testosterone during sexual maturation of male quail but additional experiments should investigate whether estrogens have such an action in females. [less ▲]

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See detailDynamic Simulations of Combined Transmission and Distribution Systems using Parallel Processing Techniques
Aristidou, Petros ULg; Van Cutsem, Thierry ULg

in Proceedings of the 18th PSCC (2014, August 22)

Simulating a power system with both transmission and distribution networks modeled in detail is a huge computational challenge. In this paper, we propose a Schur-complement-based domain decomposition ... [more ▼]

Simulating a power system with both transmission and distribution networks modeled in detail is a huge computational challenge. In this paper, we propose a Schur-complement-based domain decomposition algorithm to provide accurate, detailed dynamic simulations of the combined system. The simulation procedure is accelerated with the use of parallel programming techniques, taking advantage of the parallelization opportunities inherent in domain decomposition algorithms. The proposed algorithm is general, portable and scalable on inexpensive, shared-memory, multicore machines. A large-scale test system is used for its performance evaluation. [less ▲]

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See detailComparison of robust detection techniques for local outliers in multivariate spatial data
Ernst, Marie ULg; Haesbroeck, Gentiane ULg

Conference (2014, August 22)

Spatial data are characterized by statistical units, with known geographical positions, on which non spatial attributes are measured. Spatial data may contain two types of atypical observations: global ... [more ▼]

Spatial data are characterized by statistical units, with known geographical positions, on which non spatial attributes are measured. Spatial data may contain two types of atypical observations: global and/or local outliers. The attribute values of a global outlier are outlying with respect to the values taken by the majority of the data points while the attribute values of a local outlier are extreme when compared to those of its neighbors. Usual outlier detection techniques may be used to find global outliers as the geographical positions of the data is not taken into account in this specific search. The detection of local outliers is more complex, especially when there are more than one non spatial attributes. This talk focuses on local detection with two main objectives. First, we will shortly review some of the local detection techniques that seem to perform well in practice. Among these, one can find robust ``Mahalanobis-type'' detection techniques and a wheighted PCA approach. We suggest an adaptation to one of these to further develop its local characteristic. Then, examples and simulations, based on linear model of co-regionalisation with Matern models, are reported and discussed in order to compare in an objective way the different detection techniques. [less ▲]

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See detailIn vivo skin fluorescence imaging in young Caucasian adults with early malignant melanomas
PIERARD, Gérald ULg; Hermanns-Lê, Trinh ULg; Pierard, Sébastien ULg et al

in Clinical, Cosmetic and Investigational Dermatology (2014), 7

Background: Human cutaneous malignant melanoma (CMM) is an aggressive cancer showing a dramatic worldwide increase in incidence over the past few decades. The most prominent relative epidemiological ... [more ▼]

Background: Human cutaneous malignant melanoma (CMM) is an aggressive cancer showing a dramatic worldwide increase in incidence over the past few decades. The most prominent relative epidemiological increase has been disclosed in young women. The aim of the study was to assess the effects of chronic sun exposures in order to rate the extend of melanocytic stimulations in the vicinity of CMM. Methods: The study was designed to evaluate the melanin distribution and density using ultraviolet light illumination. The present study was performed on surgical excision specimens of thin CMM lesion removed from the upper limbs of 55 Caucasian adults (37 women and 18 men). Two control groups comprised 23 men and 21 women of similar ages who had medium-size congenital melanocytic nevi, also present on the upper limbs. The peritumoral skin was scrutinized using a Visioscan® VC98 device, revealing the faint mosaic melanoderma (FMM) pattern that grossly indicates early signs of chronic photodamage in epidermal melanin units. Results: The median extent of relative FMM was significantly higher in the CMM male group. By contrast, the CMM female group showed a reverse bimodal distribution in FMM size. Only 12/37 (32.5%) of the CMM female group had an increased FMM size, whereas 25/37 (67.5%) of females with CMM had a global FMM extent in the normal range, relative to the controls. Conclusion: Thin CMM supervening in young women appear unrelated to repeat photoexposure. Other mechanisms are possibly involved. [less ▲]

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See detailPedigree-based haplotype reconstruction, identification of cross-overs and detection of map and genotyping errors using PHASEBOOK
Druet, Tom ULg; Georges, Michel ULg

Conference (2014, August 22)

Haplotype reconstruction is important in many applications in animal genomics. In livestock species, thanks to the availability of large half-sibs families and genotyped relatives, phasing methods can ... [more ▼]

Haplotype reconstruction is important in many applications in animal genomics. In livestock species, thanks to the availability of large half-sibs families and genotyped relatives, phasing methods can rely on strong familial information and results in families with more than 10 offspring are very accurate. However, most methods are sensitive to genotyping and map errors which will be more common with next generation sequencing data. Such problems are particularly important when studying recombination rate as we plan to do in the near future. We herein describe a novel algorithm which is robust to genotyping errors and which can identify errors in marker maps. Using a large dairy cattle data set genotyped with high-density genotyping arrays, we show that the novel algorithm strongly reduces the occurrence of spurious cross-overs due to different sources of errors, and identifies map errors for most of the bovine autosomes. The implemented version is still experimental and further research will be conducted to characterize the novel method (including simulations) and to fully describe the identified map errors. [less ▲]

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See detailEcosystem Services and Agriculture
Boeraeve, Fanny ULg

Diverse speeche and writing (2014)

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See detailSensitivity based Assessment of Transient Voltage Sags caused by Rotor Swings
Weckesser, Tilman; Jóhansson, Hjörtur; Ostergaard, Jacob et al

in Proc. 18th Power System Computation Conference (2014, August 22)

The paper introduces an approach to investigate voltage sags, which are caused by large generator rotor swings following a transient disturbance. Therefore, the method exploits sensitivities derived from ... [more ▼]

The paper introduces an approach to investigate voltage sags, which are caused by large generator rotor swings following a transient disturbance. Therefore, the method exploits sensitivities derived from the algebraic network equations. These provide information on the impact of a generator on the voltage magnitude at a load bus and the effect of load variation on the generator’s power injection. It is shown that these sensitivities give valuable information to identify critical generator-load pairs and locations for applying preventive control measures. [less ▲]

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See detailModeling of the cyclic lipodepsipeptide Pseudodesmin A self-assembly through molecular dynamic simulations
Crowet, Jean-Marc ULg; Sinnaeve, Davy; Fehér, Krisztina et al

Poster (2014, August 21)

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a ... [more ▼]

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a cyclic lipodepsipeptide of nine residues which presents a moderate antibacterial activity and whose structure has been resolved by X-ray and NMR. In acetonitrile, Pseudodesmine A is monomeric while in chloroform, it has the same structure but assembles in a supramolecular complex. This structure could associate with membranes and be responsible for the biological activity of the peptide. Comparison of NMR data in the two solvents has given indications on the intermolecular contacts that arise in chloroform and a model for the self-association was proposed. To study in more details this assembly, molecular dynamics simulations have been carried on. The resultswere compared with detailed information given by NMR, regarding the dimensions of the assembly and the orientation of the individual peptide building blocks inside the supramolecular assembly. In acetonitrile, the simulations show that the peptide has transient interactions while in chloroform, interactions between monomers are always observed. In agreement with NMR, these interactions arise mainly between the backbone protons of the LEU1 and the GLN2, the GLN2 sidechain and the loop located on the opposite end of the monomer structure. From 10 simulations of dimerization, hydrogen bonds were followed and specific interaction patterns were identified regarding the hydrogen bonds formed. Peptide interactions are mainly described by 13 interaction patterns characterized by 2 to 4 hydrogen bonds. In dimers, the peptides can have a linear, a perpendicular or a side by side configuration. From the linear dimer, it is possible to reconstruct filaments and, by combining a linear and a lateral dimer, it is possible to build fibrils with multifilaments, as found in the NMR-derived model. Two self-consistent supramolecular models can be built from dimers and they present a very good correlation with NMR data regarding the supramolecular organization. Besides, the perpendicular dimer can gives peptide rings that can also explain the potential ability of this peptide to form ion pores in membranes. [less ▲]

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See detailModeling of the cyclic lipodepsipeptide Pseudodesmin A self-assembly through molecular dynamic simulations
Crowet, Jean-Marc ULg; Sinnaeve, Davy; Fehér, Krisztina et al

Conference (2014, August 20)

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a ... [more ▼]

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a cyclic lipodepsipeptide of nine residues which presents a moderate antibacterial activity and whose structure has been resolved by X-ray and NMR. In acetonitrile, Pseudodesmine A is monomeric while in chloroform, it has the same structure but assembles in a supramolecular complex. This structure could associate with membranes and be responsible for the biological activity of the peptide. Comparison of NMR data in the two solvents has given indications on the intermolecular contacts that arise in chloroform and a model for the self-association was proposed. To study in more details this assembly, molecular dynamics simulations have been carried on. The resultswere compared with detailed information given by NMR, regarding the dimensions of the assembly and the orientation of the individual peptide building blocks inside the supramolecular assembly. In acetonitrile, the simulations show that the peptide has transient interactions while in chloroform, interactions between monomers are always observed. In agreement with NMR, these interactions arise mainly between the backbone protons of the LEU1 and the GLN2, the GLN2 sidechain and the loop located on the opposite end of the monomer structure. From 10 simulations of dimerization, hydrogen bonds were followed and specific interaction patterns were identified regarding the hydrogen bonds formed. Peptide interactions are mainly described by 13 interaction patterns characterized by 2 to 4 hydrogen bonds. In dimers, the peptides can have a linear, a perpendicular or a side by side configuration. From the linear dimer, it is possible to reconstruct filaments and, by combining a linear and a lateral dimer, it is possible to build fibrils with multifilaments, as found in the NMR-derived model. Two self-consistent supramolecular models can be built from dimers and they present a very good correlation with NMR data regarding the supramolecular organization. Besides, the perpendicular dimer can gives peptide rings that can also explain the potential ability of this peptide to form ion pores in membranes. [less ▲]

Detailed reference viewed: 7 (1 ULg)
See detailLe poids d'août 1914 dans les relations belgo-allemandes (1914-1964)
Brüll, Christoph ULg

Conference (2014, August 20)

Detailed reference viewed: 5 (1 ULg)
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See detailA multifractal analysis of air temperature signals based on the wavelet leaders method
Deliège, Adrien ULg; Nicolay, Samuel ULg

Conference (2014, August 20)

We present the wavelet leaders method (introduced by S. Jaffard) as a tool to study the Hölder regularity of signals, which is closely related to some functional spaces. We use the associated multifractal ... [more ▼]

We present the wavelet leaders method (introduced by S. Jaffard) as a tool to study the Hölder regularity of signals, which is closely related to some functional spaces. We use the associated multifractal formalism to show that surface air temperature signals are monofractal, i.e. these are regularly irregular. Then we use this result to establish a climate classification of weather stations in Europe which matches the Köppen-Geiger climate classification. This result could give rise to new criteria to determine the effectiveness of current climatic models. [less ▲]

Detailed reference viewed: 12 (4 ULg)