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See detailModeling leucine's metabolic pathway and knockout prediction improving the production of surfactin, a biosurfactant from Bacillus subtilis
Coutte, François; Niehren, Joachim; Dhali, Debarun et al

in Biotechnology journal (2015), 10(8), 1216-1234

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See detailModeling Lymphangiogenesis in a three-dimensional culture system
Bruyere, Françoise; Melen-Lamalle, Laurence; Blacher, Silvia ULg et al

in Nature Methods (2008), 5(5), 431-437

Unraveling the molecular mechanisms of lymphangiogenesis is hampered by the lack of appropriate in vitro models of three-dimensional (3D) lymph vessel growth which can be used to exploit the potential of ... [more ▼]

Unraveling the molecular mechanisms of lymphangiogenesis is hampered by the lack of appropriate in vitro models of three-dimensional (3D) lymph vessel growth which can be used to exploit the potential of available transgenic mice. We developed a potent reproducible and quantifiable 3D-culture system of lymphatic endothelial cells, the lymphatic ring assay, bridging the gap between 2D-in vitro and in vivo models of lymphangiogenesis. Mice thoracic duct fragments are embedded in a collagen gel leading to the formation of lymphatic capillaries containing a lumen as assessed by electron microscopy and immunostaining. This assay phenocopies the different steps of lymphangiogenesis, including the spreading from a preexisting vessel, cell proliferation, migration and differentiation into capillaries. Our study provides evidence for the implication of an individual matrix metalloproteinase, MMP-2, during lymphangiogenesis. The lymphatic ring assay is a robust, quantifiable and reproducible system which offers new opportunities for rapid identification of unknown regulators of lymphangiogenesis. [less ▲]

Detailed reference viewed: 158 (26 ULg)
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See detailModeling medium-scale TEC structures observed by Belgian GPS receivers network
Kutiev, Ivan; Marinov, Pencho; Fidanova, Stefka et al

in Advances in Space Research (2009), 43

Detailed reference viewed: 36 (4 ULg)
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See detailModeling Microbial Cross-contamination in Quick Service Restaurants by Means of Experimental Simulations With Bacillus Spores
Baptista Rodrigues, Ana Lúcia ULg; Crevecoeur, Sébastien ULg; Dure, Remi et al

Poster (2010)

Cross contamination has been frequently mentioned as being in the origin of a wide range of food borne outbreaks. Handling of food is one of the ways through which cross contamination may occur. For many ... [more ▼]

Cross contamination has been frequently mentioned as being in the origin of a wide range of food borne outbreaks. Handling of food is one of the ways through which cross contamination may occur. For many different reasons, quick service restaurants are particularly at risk. Due to its importance, cross contamination via the hands should be taken into consideration when carrying out a quantitative risk assessment. The main goal of this study was to determine transfer rates of bacteria to and via the hands, reduction rates of two hand sanitizing procedures and to apply the results to a quantitative microbial risk assessment model. According to our results, handling of a portion of raw minced meat contaminated at 4.104 cfu leads to the presence of 24 cfu on both hands, 3 cfu on ready-to-eat product (RTE) manipulated with unwashed hands, 1 cfu on RTE manipulated with wiped hands and absence on RTE manipulated with washed hands. This study provides adequate quantitative data for quantitative microbial risk assessment. [less ▲]

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See detailModeling microdamage behavior of cortical bone
Donaldson, Finn; Ruffoni, Davide ULg; Schneider, Philipp et al

in BIOMECHANICS AND MODELING IN MECHANOBIOLOGY (2014), 13(6), 1227-1242

Bone is a complex material which exhibits several hierarchical levels of structural organization. At the submicron-scale, the local tissue porosity gives rise to discontinuities in the bone matrix which ... [more ▼]

Bone is a complex material which exhibits several hierarchical levels of structural organization. At the submicron-scale, the local tissue porosity gives rise to discontinuities in the bone matrix which have been shown to influence damage behavior. Computational tools to model the damage behavior of bone at different length scales are mostly based on finite element (FE) analysis, with a range of algorithms developed for this purpose. Although the local mechanical behavior of bone tissue is influenced by microstructural features such as bone canals and osteocyte lacunae, they are often not considered in FE damage models due to the high computational cost required to simulate across several length scales, i.e., from the loads applied at the organ level down to the stresses and strains around bone canals and osteocyte lacunae. Hence, the aim of the current study was twofold: First, a multilevel FE framework was developed to compute, starting from the loads applied at the whole bone scale, the local mechanical forces acting at the micrometer and submicrometer level. Second, three simple microdamage simulation procedures based on element removal were developed and applied to bone samples at the submicrometerscale, where cortical microporosity is included. The present microdamage algorithm produced a qualitatively analogous behavior to previous experimental tests based on stepwise mechanical compression combined with in situ synchrotron radiation computed tomography. Our results demonstrate the feasibility of simulating microdamage at a physiologically relevant scale using an image-based meshing technique and multilevel FE analysis; this allows relating microdamage behavior to intracortical bone microstructure. [less ▲]

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See detailModeling milk urea of Walloon dairy cows in management perspectives.
Bastin, Catherine ULg; Laloux, Laurent; Gillon, Alain ULg et al

in Journal of Dairy Science (2009), 92(7), 3529-40

The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management ... [more ▼]

The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management purposes. Data included 607,416 MU test-day records of first-lactation cows from 632 dairy herds in the Walloon Region of Belgium. Several advanced features were used. First, to detect the herd influence, the classical herd x test-day effect was split into 3 new effects: a fixed herd x year effect, a fixed herd x month-period effect, and a random herd test-day effect. A fixed time period regression was added in the model to take into account the yearly oscillations of MU on a population scale. Moreover, first autoregressive processes were introduced and allowed us to consider the link between successive test-day records. The variance component estimation indicated that large variance was associated with the random herd x test-day effect (48% of the total variance), suggesting the strong influence of herd management on the MU level. The heritability estimate was 0.13. By comparing observed and predicted MU levels at both the individual and herd levels, target ranges for MU concentrations were defined to take into account features of each cow and each herd. At the cow level, an MU record was considered as deviant if it was <200 or >400 mg/L (target range used in the field) and if the prediction error was >50 mg/L (indicating a significant deviation from the expected level). Approximately 7.5% of the MU records collected between June 2007 and May 2008 were beyond these thresholds. This combination allowed for the detection of potentially suspicious cows. At the herd level, the expected MU level was considered as the sum of the solutions for specific herd effects. A herd was considered as deviant from its target range when the prediction error was greater than the standard deviation of MU averaged by herd test day. Results showed that 6.7% of the herd test-day MU levels between June 2007 and May 2008 were considered deviant. These deviations seemed to occur more often during the grazing period. Although theoretical considerations developed in this study should be validated in the field, this research showed the potential use of a test-day model for analyzing functional traits to advise dairy farmers. [less ▲]

Detailed reference viewed: 101 (35 ULg)
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See detailModeling Neuronal Adaptation in the Brain: Integrating Receptor Signaling and Electrophysiology
Vadigepalli, R.; Fey, Dirk ULg; Schwaber, James S

in 2nd Conference on Foundations of Systems Biology in Engineering, Stuttgart, Germany (2007)

Detailed reference viewed: 21 (1 ULg)
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See detailModeling of 3-D losses and deviations in a throughflow analysis tool
Simon, Jean-Francois; Nicks, Alain; Paris, Nicolas et al

in Proceedings of the 8th International Symposium for Experimental and Computational Aerothermodynamics of Internal Flow (2007, July)

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See detailModeling of 3-D losses and deviations in a throughflow analysis tool
Simon, Jean-Francois; Léonard, Olivier ULg

in Journal Of Thermal Science (2007), 16(3), 208-214

This contribution is dedicated to the modeling of the end-wall flows in a throughflow model for turbomachinery applications. The throughflow model is based on the Euler or Navier-Stokes equations solved ... [more ▼]

This contribution is dedicated to the modeling of the end-wall flows in a throughflow model for turbomachinery applications. The throughflow model is based on the Euler or Navier-Stokes equations solved by a Finite-Volume technique. Two approaches are presented for the end-wall modeling. The first one is based on an inviscid formulation with dedicated 3-D distributions of loss coefficient and deviation in the end-wall regions. The second approach is directly based on a viscous formulation with no-slip boundary condition along the annular end-walls and blade force modification in the region close to the end-walls. The throughflow results are compared to a series of 3-D Navier-Stokes calculations averaged in the circumferential direction. These 3-D calculations were performed on the three rotors of a low pressure axial compressor, for a series of tip clearance values. [less ▲]

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See detailModeling of 3-D stranded inductors with the magnetic vector potential formulation and spatially dependent turn voltages of reduced support
Dular, Patrick ULg; Gyselinck, Johan

in IEEE Transactions on Magnetics (2004), 40(2, Part 2), 1298-1301

An alternative method is developed to take three-dimensional stranded inductors into account with the magnetic vector potential magnetodynamic formulation. The definition of the turn voltages as a ... [more ▼]

An alternative method is developed to take three-dimensional stranded inductors into account with the magnetic vector potential magnetodynamic formulation. The definition of the turn voltages as a continuous spatially dependent quantity of reduced support enables us to simplify the turn circuit relations, relating currents and turn voltages. The continuous extension of these relations for all the wire turns then reduces the bandwidth in the system matrix in comparison with the usual method. The voltage of each turn is, moreover, directly known and, hence, does not require a postprocessing. [less ▲]

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See detailModeling of a continuous rotary reactor for carbon nanotube synthesis by catalytic chemical vapor deposition
Pirard, Sophie ULg; Bossuot, Christophe; Pirard, Jean-Paul ULg

in AIChE Journal (2009), 55

The modeling of carbon nanotube production by the CCVD process in a continuous rotary reactor with mobile bed was performed according to a rigorous chemical reaction engineering approach. The geometric ... [more ▼]

The modeling of carbon nanotube production by the CCVD process in a continuous rotary reactor with mobile bed was performed according to a rigorous chemical reaction engineering approach. The geometric, hydrodynamic, physical and physicochemical factors governing the process were analyzed in order to establish the reactor equations. While the study of the hydrodynamic factor suggests a co-current plug-flow approximation, the physical factor mainly deals with the phenomena of transport and the transfer of mass, which can be neglected. Concerning the physicochemical factor, the modeling is based on knowledge of the expression of the initial reaction rate, and takes into account catalytic deactivation as a function of time, according to a sigmoid decreasing law. The reactor modeling allows obtaining the evolution of partial pressure, carbon nanotube production and catalytic deactivation along the reactor for given initial operating conditions. The comparison between experimental and calculated production highlights a very good fit of data. (c) 2009 American Institute of Chemical lEngineers AIChE J, 55: 675-686, 2009 [less ▲]

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See detailModeling of a glass mineral wool process in view of Life Cycle Analysis
Gerbinet, Saïcha ULg; Briard, Vincent; Léonard, Angélique ULg

in Matériaux et Techniques (2014), 102(502),

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products ... [more ▼]

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products through LCA. Knauf Insulation has several glass wool factories in Europe that produce various products, and for a specific market, the same product can be produced in several factories. As the plants that produce glass wool work with similar pathways, a generic model for LCA usable for every plant and every glass wool product has been designed. The general principle of glass wool production is the following: the raw materials, sand, limestone, soda ash, borax, sodium carbonate, as well as recycled off-cuts from the production process, are weighed and mixed. Knauf Insulation also uses a large amount of recycled glass (cullet). The mix is sent to a furnace at high temperature (1350°C). The melted material is then fiberized and the binder is added, a process called forming. Knauf Insulation uses a special binder with ECOSE Technology, a new and formaldehyde-free binder. The wool fibers are collected, by suction, on a conveyor belt, and the mattress then goes through the curing oven. For some products a facing is added. Finally the product is compressed and packed. Specific attention is put in certain LCA aspects, such as allocations procedures, and we have used ISO 14040 and 14044 along with the ILCD handbook as guides during the model development. LCA is performed from raw materials extraction to end-of-life. Nevertheless, the impacts of the insulation system use phase are not included, as they strongly depend on parameters such as construction systems, etc. The functional unit is defined as 1 m3 of specific glass mineral wool product. The model, implemented in GaBi 6, is made as generic as possible by including, for each step, all the raw materials that can be used in one of the factories as well as all the energy sources. Parameters allow to define the amount of each raw material consumed, therefore the model can be adapted to any factory simply by setting these parameters accordingly. Moreover, the transport distances are also parameters and the origin of the energies (electricity or heat) can also be selected. This simplifies the data collection, since the template is the same for all the factories, it can be supported by data collection tools already existing. A part of the model is dedicated to weighting between factories, so a combination of factories can also be studied. This allows to study products sold on a specific market. The model can also be adapted to almost all Knauf Insulation products by using parameters where necessary: for example, several products have different binder contents, so a parameter defines the amount of binder. As some materials can be recycled between several parts of the process, special attention has been paid to recycling loops inside the model. The model is flexible enough to be used for Environmental Product Declaration (EPD) as well as for Eco-Design purposes. [less ▲]

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See detailModeling of a glass mineral wool process in view of Life Cycle Analysis
Gerbinet, Saïcha ULg; Léonard, Angélique ULg; Briard, Vincent

Conference (2014, May 20)

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products ... [more ▼]

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products through LCA. Knauf Insulation has several glass wool factories in Europe that produce various products, and for a specific market, the same product can be produced in several factories. As the plants that produce glass wool work with similar pathways, a generic model for LCA usable for every plant and every glass wool product has been designed. The general principle of glass wool production is the following: the raw materials, sand, limestone, soda ash, borax, sodium carbonate, as well as recycled off-cuts from the production process, are weighed and mixed. Knauf Insulation also uses a large amount of recycled glass (cullet). The mix is sent to a furnace at high temperature (1350°C). The melted material is then fiberized and the binder is added, a process called forming. Knauf Insulation uses a special binder with ECOSE Technology, a new and formaldehyde-free binder. The wool fibers are collected, by suction, on a conveyor belt, and the mattress then goes through the curing oven. For some products a facing is added. Finally the product is compressed and packed. Specific attention is put in certain LCA aspects, such as allocations procedures, and we have used ISO 14040 and 14044 along with the ILCD handbook as guides dur-ing the model development. LCA is performed from raw materials extraction to end-of-life. Nevertheless, the impacts of the insulation system use phase are not included, as they strongly depend on parameters such as construction systems, etc. The functional unit is defined as 1 m3 of specific glass mineral wool product. The model, implemented in GaBi 6, is made as generic as possible by including, for each step, all the raw materials that can be used in one of the factories as well as all the energy sources. Parameters allow to define the amount of each raw material consumed, therefore the model can be adapted to any factory simply by setting these parameters accordingly. Moreover, the transport distances are also parameters and the origin of the energies (electricity or heat) can also be selected. This simplifies the data collection, since the template is the same for all the factories, it can be supported by data collection tools already existing. A part of the model is dedicated to weighting between factories, so a combination of factories can also be studied. This allows to study products sold on a specific market. The model can also be adapted to almost all Knauf Insulation products by using parameters where necessary: for example, several products have different binder contents, so a parameter defines the amount of binder. As some materials can be recycled between several parts of the process, special attention has been paid to recycling loops inside the model. The model is flexible enough to be used for Environmental Product Declaration (EPD) as well as for Eco-Design purposes. [less ▲]

Detailed reference viewed: 62 (6 ULg)
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See detailModeling of a glass mineral wool process in view of Life Cycle Analysis
Gerbinet, Saïcha ULg; Léonard, Angélique ULg; Briard, Vincent

Poster (2014, May 12)

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products ... [more ▼]

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products through LCA. Knauf Insulation has several glass wool factories in Europe that produce various products, and for a specific market, the same product can be produced in several factories. As the plants that produce glass wool work with similar pathways, a generic model for LCA usable for every plant and every glass wool product has been designed. Moreover, combination of different factories is also possible. The general principle of glass wool production is the following: the raw materials, sand, limestone, soda ash, borax, sodium carbonate, as well as recycled off-cuts from the production process, are weighed and mixed. Knauf Insulation also uses a large amount of recycled glass (cullet). The mix is sent to a furnace at high temperature (1350°C). The melted material is then fiberized and the binder is added, a process called forming. Knauf Insulation uses a special binder with ECOSE Technology, a new and formaldehyde-free binder. The wool fibers are collected, by suction, on a conveyor belt, and the mattress then goes through the curing oven. For some product a facing is added. Finally the product is compressed and packed. The model, implemented in GaBi 6, is made as generic as possible by including, for each step, all the raw materials that can be used in one of the factories as well as all the energy sources. Parameters allow to define the amount of each raw material consumed, therefore the model can be adapted to any factory simply by setting these parameters accordingly. This also simplifies the data collection, since the template is the same for all the factories, it can be supported by data collection tools already existing. A part of the model is dedicated to weighting between factories, so a combination of factories can also be studied. The model can also be adapted to almost all Knauf Insulation products by using parameters where necessary: for example, several products have different binder contents, so a parameter defines the amount of binder. As some materials can be recycled between several parts of the process, special attention has been paid to recycling loops inside the model. The model is flexible enough to be used for Environmental Product Declaration (EPD) as well as for Eco-Design purposes. [less ▲]

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See detailMODELING OF A GLASS WOOL PROCESS IN VIEW OF LIFE CYCLE ASSESSMENT (L.C.A.)
Gerbinet, Saïcha ULg; Renzoni, Roberto ULg; Briard, Vincent et al

Poster (2012, November)

Taking into account the environmental aspects in the building sector has become unavoidable. In France, environmental and sanitary statements for building products (“Fiches de Déclarations ... [more ▼]

Taking into account the environmental aspects in the building sector has become unavoidable. In France, environmental and sanitary statements for building products (“Fiches de Déclarations Environnementales et Sanitaires” (FDE&S)) have been developed. The environmental part of the statement is based on Life Cycle Assessment. So, KnaufInsulation, glass wool producer for the French market, has started to evaluated the environmental impacts of it process in view of FDE&S realization. The process has been modeling in GaBi with industrial data. Adjustable parameters have been introduced to allow to study the environmental impacts of almost all the KnaufInsulation products. So the FDE&S can be easily done for the different products. This model is also used for eco-conception. The LCA results allow to show the life cycle leaks. More, in modifying the model, the impact of a change in the process on its environmental performances will be highlighted. So relevant improvement will be brought out. The model and the mains results as the eco-conception strategy will be presented. The interest of making a modeling based on the step and process of the life cycle of a product or a product range will be clearly understood. [less ▲]

Detailed reference viewed: 46 (1 ULg)
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See detailMODELING OF A GLASS WOOL PROCESS IN VIEW OF LIFE CYCLE ASSESSMENT (L.C.A.)
Gerbinet, Saïcha ULg; Renzoni, Roberto ULg; Briard, Vincent et al

in LCA conference 2012 - Proceeding of the 2nd international conference on life cycle approaches (2012, November)

Taking into account the environmental aspects in the building sector has become unavoidable. In France, environmental and sanitary statements for building products (“Fiches de Déclarations ... [more ▼]

Taking into account the environmental aspects in the building sector has become unavoidable. In France, environmental and sanitary statements for building products (“Fiches de Déclarations Environnementales et Sanitaires” (FDE&S)) have been developed. The environmental part of the statement is based on Life Cycle Assessment. So, KnaufInsulation, glass wool producer for the French market, has started to evaluated the environmental impacts of it process in view of FDE&S realization. The process has been modeling in GaBi with industrial data. Adjustable parameters have been introduced to allow to study the environmental impacts of almost all the KnaufInsulation products. So the FDE&S can be easily done for the different products. This model is also used for eco-conception. The LCA results allow to show the life cycle leaks. More, in modifying the model, the impact of a change in the process on its environmental performances will be highlighted. So relevant improvement will be brought out. The model and the mains results as the eco-conception strategy will be presented. The interest of making a modeling based on the step and process of the life cycle of a product or a product range will be clearly understood. [less ▲]

Detailed reference viewed: 87 (7 ULg)