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See detailOn the compatibility equations in geometrically exact beam finite element
Sonneville; Bruls, Olivier ULg; Bauchau, Olivier A.

in Proceedings of the 12th International Conference on Multibody Systems, Nonlinear Dynamics and Control (MSNDC) within the ASME/IDETC/CIE Conference (2016, August)

This paper discusses the compatibility equations which relate the velocity field and the strain field in geometrically exact beam theory. The analysis is carried out in the context of intrinsic equations ... [more ▼]

This paper discusses the compatibility equations which relate the velocity field and the strain field in geometrically exact beam theory. The analysis is carried out in the context of intrinsic equations, namely the dynamic equilibrium equations are formulated in terms of velocity and strain only. In addition to the well established objectivity and path-independence requirements of the spatial discretization, these compatibility equations show that a consistent spatial interpolation of the velocity field should depend on the curvature of the beam, including initial curvature and curvature from the deformation, and it is shown that this consistency is connected to the ability of the element to represent rigid body motion velocity. A two node interpolation scheme is studied and it appears that, as the element gets smaller under mesh refinement, the effect of this dependency reduces, leading eventually to the classical linear shape functions. [less ▲]

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See detailModelling of multibody systems in the local frame
Bruls, Olivier ULg; Sonneville, Valentin

in Proceedings of the 24th International Congress of Theoretical and Applied Mechanics (ICTAM) (2016, August)

A local frame finite element approach is proposed to describe the kinematics of a flexible multibody system, derive the equations of motion and solve them numerically. It is argued that this approach ... [more ▼]

A local frame finite element approach is proposed to describe the kinematics of a flexible multibody system, derive the equations of motion and solve them numerically. It is argued that this approach leads to reduced geometric nonlinearities and improved computational efficiency. [less ▲]

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See detailOptimal design of flexible mechanisms using a generalized equivalent static load method
Tromme, Emmanuel; Sonneville, Valentin; Guest, James K. et al

in Proceedings of the 24th International Congress of Theoretical and Applied Mechanics (2016, August)

The equivalent static load (ESL) method is a powerful approach to solve dynamic response structural optimization problems. The method transforms the dynamic response optimization into a static response ... [more ▼]

The equivalent static load (ESL) method is a powerful approach to solve dynamic response structural optimization problems. The method transforms the dynamic response optimization into a static response optimization under multiple load cases. The ESLs are defined based on the transient analysis response whereupon all the standard techniques of static response optimization can be used. In the last decade, the ESL method has been applied to perform structural optimization of flexible components of mechanical systems modeled as multibody systems. This method considers the optimization of isolated component during the static response optimization. The present research proposes a generalized ESL method accounting for the entire system during the static response optimization, which enables to formulate the constraints with respect to the mechanism and not restricted to the individual components. The proposed method relies on a Lie group formalism which has appealing properties to derive efficiently the ESL. Examples validate the method. [less ▲]

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See detailMaladie de l'herbe (Dysautonomie Equine ou Equine Grass Sickness ) : une nouvelle étude dans le cadre du RESPE
Tritz, Pierre; Laugier, Claire; Trapprest, Jackie et al

Learning material (2016)

La maladie de l’herbe (MH) (dysautonomie équine, Equine Grass Sickness) est une polyneuropathie qui atteint le système nerveux central et périphérique chez le cheval. Cette maladie d’étiologie inconnue ... [more ▼]

La maladie de l’herbe (MH) (dysautonomie équine, Equine Grass Sickness) est une polyneuropathie qui atteint le système nerveux central et périphérique chez le cheval. Cette maladie d’étiologie inconnue atteint presque exclusivement les chevaux à l’herbe qui développent des symptômes caractéristiques en relation avec une dégénérescence neuronale dans le système nerveux autonome et dans l'innervation intestinale. Les formes aiguës et subaiguës de la maladie sont presque toujours fatales. La maladie est essentiellement décrite dans les iles britanniques et n’a fait l’objet que de très rares études et publications en France dont une étude de la commission maladies infectieuses de l’AVEF. Quelques cas ont été recensés par le RESPE, qui est alerté régulièrement par des vétérinaires ou des propriétaires inquiets, ce qui a conduit le Conseil Scientifique et Technique (CST) du RESPE à relancer une nouvelle étude épidémiologique sur cette maladie en France en collaboration avec le laboratoire de pathologie équine de l’ANSES et l’institut Pasteur (unité des toxines et pathogénie bactériennes, zone anaérobie). [less ▲]

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See detailAnalysing hypoglycin A, methylenecyclopropylacetic acid conjugates and acylcarnitines in blood to confirm the diagnosis and improve our understanding of atypical myopathy
Votion, Dominique ULg

in Equine Veterinary Education (2016), doi: 10.1111/eve.12617

Owing to recent methodological validation studies, we have now the opportunity to determine hypoglycin A, methylenecyclopropylacetic acid–carnitine and acylcarnitines concentrations in equine serum. These ... [more ▼]

Owing to recent methodological validation studies, we have now the opportunity to determine hypoglycin A, methylenecyclopropylacetic acid–carnitine and acylcarnitines concentrations in equine serum. These analytes are essential to confirm the diagnosis of atypical myopathy but also to improve our understanding of the pathophysiology of the disease. In particular, they might help elucidate why some horses seem more resistant to hypoglycin A poisoning. [less ▲]

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See detailAmphibians breeding in refuge habitats have larvae with stronger antipredator responses
Manenti, Raoul; Melotto, Andrea; Denoël, Mathieu ULg et al

in Animal Behaviour (2016), 118

Antipredator responses are a key determinant of the successful persistence of prey, and behavioural modifications are a frequent antipredator strategy. However, conspecific populations often inhabit ... [more ▼]

Antipredator responses are a key determinant of the successful persistence of prey, and behavioural modifications are a frequent antipredator strategy. However, conspecific populations often inhabit heterogeneous environments. This can determine local adaptations, and might also induce variation in antipredator responses. Nevertheless, there is limited information on whether heterogeneity of predation risk among populations determines variation in antipredator response. Here we studied the fire salamander, Salamandra salamandra, a species that can breed in both surface streams and caves, habitats that are predator-rich and predator-free, respectively, and measured differences in antipredator responses across populations with different predation risk. We combined field surveys and laboratory experiments to understand the role of predation risk on the activity patterns of larvae, while measuring behavioural differences between populations. We reared larvae from different habitats in safe and risky conditions and tested their response to predator cues before and after rearing. In the field, predation risk was much higher in surface streams than in caves; larvae moved more in the absence of predators and when the light intensity was low. During laboratory experiments, larvae were less active if reared in risky conditions, but cave larvae showed a stronger response to risk than stream larvae. Therefore, larvae from sites without predators showed higher antipredator responses than those from risky habitats. This response fits the predictions of the risk allocation model, in which prey from habitats with a high background level of risk need to be active even when predators are present, to satisfy their energetic demands. Our findings show that antipredator behaviour may differ strongly between populations and stress the importance of integrating this variability in studies on predatory responses. [less ▲]

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See detailAutomatic learning of fine operating rules for online power system security control
Sun, Hongbin; Zhao, Feng; Wang, Huifang et al

in IEEE Transactions on Neural networks and learning systems (2016), 27(8), 1708-1719

Fine operating rules for security control and an automatic system for their online discovery were developed to adapt to the development of smart grids. The automatic system uses the real-time system state ... [more ▼]

Fine operating rules for security control and an automatic system for their online discovery were developed to adapt to the development of smart grids. The automatic system uses the real-time system state to determine critical flowgates, and then a continuation power flow-based security analysis is used to compute the initial transfer capability of critical flowgates. Next, the system applies the Monte Carlo simulations to expected short-term operating condition changes, feature selection, and a linear least squares fitting of the fine operating rules. The proposed system was validated both on an academic test system and on a provincial power system in China. The results indicated that the derived rules provide accuracy and good interpretability and are suitable for real-time power system security control. The use of high-performance computing systems enables these fine operating rules to be refreshed online every 15 min. [less ▲]

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See detailHydrocarbon biostimulation and bioaugmentation in organic carbon and clay-rich soils
Masy, Thibaut ULg; Demanèche, Sandrine; Tromme, Olivier et al

in Soil Biology & Biochemistry (2016), 99

Hydrocarbon-contaminated organic carbon-rich clayey soils are challenging for bioremediation stakeholders since the pollutant is heterogeneously distributed and poorly bioavailable due to its strong ... [more ▼]

Hydrocarbon-contaminated organic carbon-rich clayey soils are challenging for bioremediation stakeholders since the pollutant is heterogeneously distributed and poorly bioavailable due to its strong adsorption on clay and organic particles. In addition, biodegradation rates are restricted by limited diffusion of oxygen and nutrients to hydrocarbon-degrading aerobes. This study assessed the benefits of bioaugmentation with the strain Rhodococcus erythropolis T902.1 versus those from biostimulation and anaerobic natural attenuation in terms of hydrocarbon (HC) degradation efficiency and changes in the bacterial community structure in a diesel-polluted clay-rich soil. Three soil samples with a similar total organic content but with a different HC concentration (0.2, 1.0 and 6.5 g/kg) were compared in a microcosm experiment. Despite a limitation in oxygen transfer, R. erythropolis T902.1 enhanced a greater HC degradation compared to the biostimulation treatment. However, this advantage decreased with time as the proportion of Rhodococci declined from 25% initially to 1% of the global community after 80 days of treatment. Similarly, the alkB gene proportion in bioaugmented soils decreased to levels close to those of biostimulated soils. Consequently, further engineering was suggested to improve the resilience of the inoculum to ensure its long-term presence and activity in such polluted environments. [less ▲]

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See detailSynthèse des données gétechniques nécessaires à l'étude de la stabilité de cinq terrils à risque en région wallonne - phase2
Delvoie, Simon ULg; Collin, Frédéric ULg

Report (2016)

Dans le cadre d’un recensement des terrils situés en Région wallonne et pouvant présenter des risques de stabilité sur le court et le long terme, l’ISSeP a chargé le Laboratoire de Géotechnologies de ... [more ▼]

Dans le cadre d’un recensement des terrils situés en Région wallonne et pouvant présenter des risques de stabilité sur le court et le long terme, l’ISSeP a chargé le Laboratoire de Géotechnologies de l’Université de Liège, représenté par Ir. F. COLLIN et S. DELVOIE, de réaliser une étude géotechnique préliminaire. Les objectifs de ce travail sont tout d’abord de recenser les informations disponibles sur le sous-sol aux environs immédiats des terrils. Les données recueillies sont ensuite exploitées par des outils informatiques SIG et seront par la suite utilisées dans l’évaluation du risque d’instabilité, réalisée par l’ISSeP. Ce travail documentaire est également complété par une inspection sur le terrain de chaque terril étudié. Les terrils faisant partie de l’étude géotechnique sont repris dans la liste ci-dessous : - Argenteau Ancien et Argenteau Nouveau – OBID 578-579 – L6 et L7 - Saint-Placide – OBID 343 – B60 - 14-17 et Siège social – OBID 5151 – B80-1 - Héribus – OBID 557 – B88-1 - Crachet 7/12 – OBID 286 – B111 [less ▲]

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See detailCrossroads - le magazine sonore du blues et des musiques africaines américaines
Sacré, Robert ULg

Diverse speeche and writing (2016)

Programme radio hebdomadaire consacré aux musiques africaines américaines ; en streaming: www.equinoxefm.be ; les podcasts www.mixcloud.com/robertsacre9

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See detailThe Economic Forces Behind Deindustrialization: An Empirical Investigation
Van Neuss, Leif ULg

E-print/Working paper (2016)

The purpose of this paper is to provide an in-depth study of deindustrialization and to systematically analyze the reasons why the world’s most economically successful countries have experienced a sharp ... [more ▼]

The purpose of this paper is to provide an in-depth study of deindustrialization and to systematically analyze the reasons why the world’s most economically successful countries have experienced a sharp decline in relative manufacturing employment over the last decades. A large strand of empirical literature on deindustrialization aims at quantifying the relative importance of the economic forces behind deindustrialization, especially of the ‘internal’ and ‘external’ factors. While this study does not contradict the widespread belief that internal factors are quantitatively more important in explaining deindustrialization in advanced countries taken as a whole, our results, based on both static and dynamic techniques and panel data on 18 OECD countries from 1977 to 2007, however suggest that the role of globalization may be revised upwards when resorting to appropriate and well-defined indicators of trade in manufactures. [less ▲]

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See detailBack to the Future of Dioxin Analyses
Patterson Jr, D; Focant, Jean-François ULg

Conference (2016, August)

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See detailREVISITED SAMPLE PREPARATION APPROACH FOR DIOXIN MEASUREMENTS IN HUMAN SERUM SAMPLES
Calaprice, Chiara ULg; Focant, Jean-François ULg

in Organohalogen Compounds (2016, August), 78

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See detailA general methodology for optimal load management with distributed renewable energy generation and storage in residential housing
Georges, Emeline ULg; Braun, James; Lemort, Vincent ULg

in Journal of Building Performance Simulation [=JBPS] (2016)

In the US, buildings represent around 40% of the primary energy consumption and 74% of the electrical energy consumption [U.S. Department of Energy (DOE). 2012. 2011 Buildings Energy Data Book. Energy ... [more ▼]

In the US, buildings represent around 40% of the primary energy consumption and 74% of the electrical energy consumption [U.S. Department of Energy (DOE). 2012. 2011 Buildings Energy Data Book. Energy Efficiency & Renewable Energy]. Incentives to promote the installation of on-site renewable energy sources have emerged in different states, including net metering programmes. The fast spread of such distributed power generation represents additional challenges for the management of the electricity grid and has led to increased interest in smart control of building loads and demand response programmes. This paper presents a general methodology for assessing opportunities associated with optimal load management in response to evolving utility incentives for residential buildings that employ renewable energy sources and energy storage. An optimal control problem is formulated for manipulating thermostatically controlled domestic loads and energy storage in response to the availability of renewable energy generation and utility net metering incentives. The methodology is demonstrated for a typical American house built in the 1990s and equipped with a single-speed air-to-air heat pump, an electric water heater and photovoltaic (PV) collectors. The additional potential associated with utilizing electrical batteries is also considered. Load matching performance for on-site renewable energy generation is characterized in terms of percentage of the electricity production consumed on-site and the proportion of the demand covered. For the purpose of assessing potential, simulations were performed assuming perfect predictions of the electrical load profiles. The method also allows determination of the optimal size of PV systems for a given net metering programme. Results of the case study showed significant benefits associated with control optimization including an increase of load matching between 3% and 28%, with the improvement dependent on the net metering tariff and available storage capacity. The estimated cost savings for the consumer ranged from 6.4% to 27.5% compared to no optimization with a unitary buy-back ratio, depending on the available storage capacity. Related reduction in CO2 emissions were between 11% and 46%. Optimal load management of the home thermal systems allowed an increase in the optimal size of the PV system in the range of 13–21%. [less ▲]

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See detailMonitoring of anatabine release by methyl jasmonate elicited BY-2 cells using surface-enhanced Raman scattering
De Bleye, Charlotte ULg; Dumont, Elodie ULg; Dispas, Amandine ULg et al

in Talanta (2016), 160

A new application of surface-enhanced Raman scattering (SERS) in the field of plant material analysis is proposed in this study. The aim was to monitor the release of anatabine by methyl jasmonate (MeJa ... [more ▼]

A new application of surface-enhanced Raman scattering (SERS) in the field of plant material analysis is proposed in this study. The aim was to monitor the release of anatabine by methyl jasmonate (MeJa) elicited Bright Yellow-2 (BY-2) cells. Gold nanoparticles (AuNps) were used as SERS substrate. The first step was to study the SERS activity of anatabine in a complex matrix comprising the culture medium and BY-2 cells. The second step was the calibration. This one was successfully performed directly in the culture medium in order to take into account the matrix effect, by spiking the medium with different concentrations of anatabine, leading to solutions ranging from 250 to 5000 µg L-1. A univariate analysis was performed, the intensity of a band situated at 1028 cm-1, related to anatabine, was plotted against the anatabine concentration. A linear relationship was observed with a R2 of 0.9951. During the monitoring study, after the MeJa elicitation, samples were collected from the culture medium containing BY-2 cells at 0, 24h, 48h, 72h and 96h and were analyzed using SERS. Finally, the amount of anatabine released in the culture medium was determined using the response function, reaching a plateau after 72h of 82 µg of anatabine released / g of fresh weight (FW) MeJa elicited BY-2 cells. [less ▲]

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See detailBiocompatibility of polymer-infiltrated-ceramic-network (PICN) materials with Human Gingival Fibroblasts (HGFs).
GRENADE, Charlotte ULg; De Pauw-Gillet, Marie-Claire ULg; Gailly, Patrick ULg et al

in Dental materials : official publication of the Academy of Dental Materials (2016)

OBJECTIVES: Polymer-infiltrated-ceramic-network (PICN) materials constitute an innovative class of CAD-CAM materials offering promising perspectives in prosthodontics, but no data are available in the ... [more ▼]

OBJECTIVES: Polymer-infiltrated-ceramic-network (PICN) materials constitute an innovative class of CAD-CAM materials offering promising perspectives in prosthodontics, but no data are available in the literature regarding their biological properties. The objective of the present study was to evaluate the in vitro biocompatibility of PICNs with human gingival fibroblasts (HGFs) in comparison with materials typically used for implant prostheses and abutments. METHODS: HGF attachment, proliferation and spreading on discs made of PICN, grade V titanium (Ti), yttrium zirconia (Zi), lithium disilicate glass-ceramic (eM) and polytetrafluoroethylene (negative control), were evaluated using a specific insert-based culture system (IBS-R). Sample surface properties were characterized by XPS, contact angle measurement, profilometry and SEM. RESULTS: Ti and Zi gave the best results regarding HGF viability, morphology, number and coverage increase with time in comparison with the negative control, while PICN and eM gave intermediate results, cell spreading being comparable for PICN, Ti, Zi and eM. Despite the presence of polymers and their related hydrophobicity, PICN exhibited comparable results to glass-ceramic materials, which could be explained by the mode of polymerization of the monomers. SIGNIFICANCE: The results of the present study confirm that the currently employed materials, i.e. Ti and Zi, can be considered to be the gold standard of materials in terms of HGF behavior, while PICN gave intermediate results comparable to eM. The impact of the present in vitro results needs to be further investigated clinically, particularly in the view of the utilization of PICNs for prostheses on bone-level implants. [less ▲]

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See detailThey will need land! The current land tenure situation and future land allocation needs of smallholder farmers in Cambodia
Diepart, Jean-Christophe ULg

E-print/Working paper (2016)

The objective of this background paper is to provide a succinct description of the land tenure situation in Cambodia and, on that basis, discuss the needs smallholder farmers have for land, projected up ... [more ▼]

The objective of this background paper is to provide a succinct description of the land tenure situation in Cambodia and, on that basis, discuss the needs smallholder farmers have for land, projected up to the year 2030. The main problem it examines lies at the intersection between, on one hand, the demographic increase in the rural smallholder population and its associated need for land in the future (the demand side) and, on the other hand, the possibility offered by the different land tenure regimes to meet this demand (the supply side); the central question focuses on how supply can meet demand.By looking first at how much land is available under different categories (the supply side), the paper succinctly presents and maps the different land tenure regimes with updated statistics and discusses their main outcomes and shortcomings. On that basis, we present a preliminary assessment of land distribution by main land tenure systems in Cambodia. The land under cultivation by smallholders represents 19 percent of the total area of the national territory and is itself sub-divided into agricultural land with land titles (systematic land registration, 6 percent and land covered by the Order 01, 6 percent), under Social Land Concession arrangements (1 percent) and untitled (6 percent). The forest cover includes forest concessions (10 percent), Community Forestry (2 percent), Protected Areas and Protection Forests (20 percent) and an unclassified forest cover area (14 percent). Economic Land Concessions under operation represent 12 percent while cancelled concessions represent 2 percent of the total territory. The actual tenure of a large non-forested area (14 percent) remains undetermined and further updates are needed to shed light on this issue. The paper suggests that the central problem of the current Cambodian land reform is its ineffectiveness in coordinating the processes of land rights security and formalization in lowland and upland areas, although both regions are closely linked through land-driven migration movements that have intensified over the past 20 years. This has been particularly contentious given the fact that in a parallel process, and driven by a strong, state-based political economy, large land deals have been concentrated in the uplands of the entire country along processes that are exclusionary in nature. The overlap of competing land claims has created a widespread conflict situation in all uplands region of the country. By looking at how much land is needed for family farmers in the future (the demand side), the paper anticipates the land requirements of smallholder farmers by 2030 based on the projected demographic increase in the economically active population in rural Cambodia and on two sets of scenarios i) the transfer of unskilled labour from the agricultural to the secondary and tertiary sectors (industries and services) and ii) the provision of land for smallholder farmers. The analysis suggests that by the year 2030, the transfer of unskilled labour from agriculture to the secondary and tertiary sectors will lag behind the demographic increase in the active rural population. With 2015 as a baseline, the scenarios suggests that by 2030 smallholder farmers will need an additional land area ranging from 320,600 ha (+10 percent in relation to the actual area at the present time) to 1,962,400 (+64 percent), with an average desirable scenario of 1,622.000 ha based on an allocation of 1ha per active labourer (in accordance with the present social concession policy) and on the continuation of the present transfer rate of unskilled manpower from agriculture to the secondary and tertiary sectors (i.e. the transfer of 40.000 workers per year). So the question that needs to be formulated does not revolve around whether or not the rural population will need land in the future, but rather around how this can occur. Along these lines, the paper discusses different options, which are not mutually exclusive, to allocate this land without further impact on the forest cover: i) by redistribution of land from cancelled Economic Land Concessions, ii) through a firmer recognition of swidden agriculture inside Protected Areas, iii) through a far more ambitious Social Land Concession programme and iv) through further reform of the forest concession system. The paper concludes by stressing the need for relevant ministries to engage in open and constructive research-based discussion so that these options can materialize into concrete actions. [less ▲]

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