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See detailFeasibility study of repetitive diffusion MRI after Neoadjuvant radiotherapy for following tumor microenvironment.
LALLEMAND, François ULg; Leroi, Natacha ULg; Bahri, Mohamed Ali ULg et al

Conference (2016, March 22)

Purpose/Objective. Neoadjuvant radiotherapy (NeoRT) improves tumor local control and tumor resection in many cancers. The timing between the end of the NeoRT and surgery is mostly driven by the occurrence ... [more ▼]

Purpose/Objective. Neoadjuvant radiotherapy (NeoRT) improves tumor local control and tumor resection in many cancers. The timing between the end of the NeoRT and surgery is mostly driven by the occurrence of side effects or the tumor downsizing. We previously demonstrated in an in vivo model that the timing of surgery and the schedule of NeoRT influenced the tumor dissemination. Here, our aim is to evaluate with functional MRI (fMRI) the impact of the radiation treatment on the tumor microenvironment and subsequently to identify non-invasive markers helping to determine the best timing to perform surgery for avoiding tumor spreading. First, we needed to demonstrate the feasibility of repetitive MRI imaging after NeoRT in mice. Material/methods. We used two models of NeoRT we previously developed in mice: MDA-MB 231 and 4T1 cells implanted in the flank of mice. When tumors reached the planned volume, they are irradiated with 2x5 Gy and then surgically removed at different time points after RT. In the mean time between the end of RT and the surgical procedure, mice were imaged in a 9,4T Agilent® MRI. Diffusion Weighted (DW) -MRI was performed every 2 days between RT and surgery. For each tumors we acquired 8 slices of 1 mm thickness and 0.5 mm gap with an “in plane voxel resolution” of 0.5 mm. For DW-MRI, we performed FSEMS (Fast Spin Echo MultiSlice) sequences, with 9 different B-values (from 40 to 1000) and B0, in the 3 main directions. We also performed IVIM (IntraVoxel Incoherent Motion) analysis, in the aim to obtain information on intravascular diffusion, related to perfusion (F: perfusion factor) and subsequently tumor vessels perfusion. Results. As preliminary results, with the MBA-MB 231 we observed a significant increase of F at day 6 after irradiation than a decrease and stabilization until surgery. No other modifications of the MRI signal, ADC, D or D* were observed. We observed similar results with 4T1 cells, F increased at day 3 than returned to initial signal. The difference in the timing of the peak of F can be related to the difference in tumor growth between MBA-MB 231 and 4T1 (four weeks vs one week). Conclusion. For the first time, we demonstrate the feasibility of repetitive fMRI imaging in mice models after NeoRT. With these models, we show a significant peak of the perfusion factor (F) at day 6 or day 3. This change occurs between the two previous time points of surgery demonstrating a difference in the metastatic spreading. Indeed, after a NeoRT of 2X5Gy we observed more metastases in the lung when MDA-MB 231 tumor bearing mice are operated 4 days after RT compared to 11 days. These preliminary results are very promising for identifying noninvasive markers for determining the best timing for surgery. [less ▲]

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See detailFEASIBILITY STUDY OF SLUDGE TRANSPORT BY INLAND WATERWAYS
Marchal, Jean ULg; Ndiaye, Alassane-Ballé ULg; Zhang, Zhaomin

in Bulletin de l’Association Internationale Permanente des Congrès de Navigation [Bulletin de l'AIPCN] (2006)

There are significant economic and environmental interests to transport the sludge, which comes from the sewage treatment plants, to the incinerators by inland waterways. Due to the physical and chemical ... [more ▼]

There are significant economic and environmental interests to transport the sludge, which comes from the sewage treatment plants, to the incinerators by inland waterways. Due to the physical and chemical characteristics of the sludge, conventional means of waterway transport meet with the limits and the new technologies should be introduced, especially in the aspects of sludge holding and handling. This paper will introduce briefly the study made for the local communities in the region Walloon (Belgium) to establish such systems of sludge transport by inland waterways. The study covered the handling and holding techniques, the optimal shipping operations, and the socio-economic benefits assessments. [less ▲]

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See detailFeasibility study of the development of Intermodal Freight transport between Belgium and Bulgaria
Marchal, Jean ULg; KISHEVA, Diana; ZHANG, Zhaomin

in Port Development and Coastal Environment (2003, June 04), PDCE 2003

The aim of the project was to perform a feasibility study for possible development of freight intermodal transport links between Belgium and Bulgaria, between North and Black sea and vice versa, taking ... [more ▼]

The aim of the project was to perform a feasibility study for possible development of freight intermodal transport links between Belgium and Bulgaria, between North and Black sea and vice versa, taking inland waterways (iww) transport mode as basic one. The key focus is assessment of benefits in adopting an intermodal manner for transferring cargo instead of the single transport mode currently in use. The paper comprises short description of trans-continental infrastructure between Belgium and Bulgaria and its abilities to serve for different transport alternatives, definitions and choice of appropriate scenarios for realising predicted cargo flows, as well as cost calculations. Comparative analysis of the considered transport alternatives has been made. The most important results obtained are transport cost evaluation and benefit assessment for investigated transport scenarios [less ▲]

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See detailFeasibility study of the diluted combustion in a domestic heating boiler
SEGGIO, Giovanni; Ngendakumana, Philippe ULg; PESENTI, Barbara et al

in 4th European Combustion Meeting (ECM2009) (2009, April)

The diluted combustion (called also flameless oxidation) has been already applied in furnaces technology to get high process thermal efficiency with low NOx emissions. The principle of this type of ... [more ▼]

The diluted combustion (called also flameless oxidation) has been already applied in furnaces technology to get high process thermal efficiency with low NOx emissions. The principle of this type of combustion consists in providing a high level of dilution of the reactants with flue gases before combustion reaction occurs, to get a slower reaction in a much larger volume than in classical combustion. The resulting lower local heat release leads to a more homogeneous temperature field in the furnace, without peak values responsible of high thermal NOx formation. There are two requirements for working in diluted combustion: the dilution level of reactants by the flue gases has to be high enough and the temperature level in the combustion chamber has to be above a threshold (the auto-ignition temperature of the mixture). The aim of this work is to assess the technical feasibility and highlight the specific problems of application of diluted combustion in a medium scale boiler. The main difficulty is due to the high geometrical confinement and heat losses of a typical boiler combustion chamber. That prevents from getting the minimum level of reactants dilution and temperature needed to reach diluted combustion regime. The idea is to use a natural gas jet-burner (to preheat the combustion chamber) along with a secondary gas injector in order to get a high entrainment of the flue gases by the reactant jets. In fact the air (through the jet-burner) and the gas (through the secondary gas injector) are injected separately in order to get a high dilution of the reactants and a mixture temperature above the auto-ignition threshold. Our test bench consists in a Viessmann hot water boiler whose nominal output power is 370 kW. The combustion chamber of this boiler is cylindrical (length = 1.41 m, diameter = 0.56 m) and is water-cooled. A preliminary CFD study (Fluent ®) has first been performed to select on the market a jet burner and to determine the position of the air and gas injectors able to generate the requirements of diluted combustion. The influence of the operating conditions (firing rate and excess air) has also been studied numerically. The simulation results show the possibility to obtain a temperature field quite homogenous (typical of diluted combustion) but with a light increase of the CO level at the exit of the combustion chamber. These numerical results (obtained with a simple combustion model) have to be validated experimentally. A first experimental study has been carried out in classical combustion on the boiler equipped with the selected jet-burner. The temperature field has been measured in the median plane of the combustion chamber for different excess air and firing rate. These measurements allowed us to verify that the preheating obtained with the jet-burner was important enough for getting a temperature level above the auto-ignition temperature near everywhere in the combustion chamber. A second experimental study in diluted combustion on the combustion chamber equipped with the secondary gas injector will allow the validation the corresponding numerical results. [less ▲]

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See detailFeasibility study of the diluted combustion in a semi-industrial boiler at low temperatures
Seggio, Giovanni; Ngendakumana, Philippe ULg; Pesenti, Barbara et al

Conference (2007, September)

The aim of this work is to assess the technical feasibility and highlight the specific problem of application of diluted (or mild) combustion in a medium scale boiler by direct gas injection. The main ... [more ▼]

The aim of this work is to assess the technical feasibility and highlight the specific problem of application of diluted (or mild) combustion in a medium scale boiler by direct gas injection. The main difficulty is due to the high geometrical confinement and heat losses of a typical boiler combustion chamber, which prevents from getting the minimum level of reactants dilution and temperature needed to reach mild combustion regime. Last year, a preliminary CFD study was performed to select a jet burner and secondary gas injector able to generate sufficient dilution and temperature of the air and gas jets before they meet in the combustion chamber of the boiler. In this work, the optimization of the position and the diameter of the gas injector has been performed. Finally, the boundary conditions and the parameters of the combustion model have been investigated. [less ▲]

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See detailFeasibility study of the diluted combustion in a semi-industrial boiler at low temperatures
SEGGIO, Giovanni; PESENTI, Barbara; LYBAERT, Paul et al

in 8th European Conference on Industrial Furnaces and Boilers (2008, March)

The diluted combustion (called also flameless oxidation) has been already applied in furnaces technology to get high process thermal efficiency with low NOx emissions. The aim of this work is to assess ... [more ▼]

The diluted combustion (called also flameless oxidation) has been already applied in furnaces technology to get high process thermal efficiency with low NOx emissions. The aim of this work is to assess the technical feasibility and highlight the specific problems of application of diluted combustion in a medium scale boiler. The main difficulty is due to the high geometrical confinement and heat losses of a typical boiler combustion chamber, which could prevent from getting the minimum level of reactants dilution and temperature needed to reach diluted combustion regime. The idea is to perform direct injection of the air and the gas in the combustion chamber in order to get a high dilution of the reactants and a mixture temperature above the auto-ignition threshold. Our test bench consists in a Viessmann hot water boiler whose nominal output power is 370 kW. The combustion chamber of this boiler is cylindrical (length = 1.41 m, diameter = 0.56 m) and is watercooled. A preliminary CFD study (Fluent ®) has first been performed to select on the market a jet burner (to be used for the preheating of the combustion chamber) and to determine the position of the air and gas injectors able to generate the requirements of diluted combustion. The selected burner has been purchased and fitted on the boiler. Then, the boiler-burner set has been characterized experimentally in normal combustion regime in order to adapt the boundary conditions to the heat balance. The temperature and the CO concentration will be measured in several locations in the combustion chamber at different firing rate and air excess. In short, the selected burner provides as expected the required preheating and the generated flame doesn’t impact the bottom of the combustion chamber. The results obtained experimentally confirm the simulation results in normal combustion regime. The last part of this work will consist in the determination of the feasibility of the diluted combustion in this boiler. [less ▲]

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See detailFeasibility study of the diluted combustion in a semi-industrial domestic heating boiler at low temperatures
SEGGIO, Giovanni; Ngendakumana, Philippe ULg; PESENTI, Barbara et al

Conference (2006, August)

The aim of this work is to assess the technical feasibility and highlight the specific problem of application of diluted (or mild) combustion in a medium scale boiler by direct gas injection. The main ... [more ▼]

The aim of this work is to assess the technical feasibility and highlight the specific problem of application of diluted (or mild) combustion in a medium scale boiler by direct gas injection. The main difficulty is due to the high geometrical confinement and heat losses of a typical boiler combustion chamber, which prevents from getting the minimum level of reactants dilution and temperature needed to reach mild combustion regime. In this work, a preliminary CFD study has been performed to select a jet burner and secondary gas injector able to generate sufficient dilution and temperature of the air and gas jets before they meet in the combustion chamber of the boiler. [less ▲]

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See detailFeasibility study of the modernization of Wielingen class frigates
Marchal, Jean ULg; Hage, André ULg; Dessart, Christophe et al

(2006, September 25)

The research group MRN04 has made a study of modernization of frigates of the Belgian Navy. The modernization includes fitting out of a landing area for an 11 tonnes helicopter, modifying the ... [more ▼]

The research group MRN04 has made a study of modernization of frigates of the Belgian Navy. The modernization includes fitting out of a landing area for an 11 tonnes helicopter, modifying the superstructure to solve the problems of cracks and reducing the radar cross section. The proposal of the group MRN04 consists of widening and stiffness the stern deck in order to permit landing of a helicopter, surrounding the existing superstructure by a new envelop having a better furtivity. The resistance of the helicopter landing area and the rigidity of the superstructure has been estimated by structural computations by finite elements method, which permits to choose the most adequate structure. Once the weight of the new elements is known, a new estimation of the weight is established. It permits to calculate the draft and the trim, and serves as the data to calculate the ship resistance. In fact, the speed of the frigate, as a crucial point, should not decrease too much. The ship resistance will be obtained by means of model tests in the towing tank in the University of Liège. The study shows the possibility to lay out a landing area for a helicopter of 11 tonnes as well as to decrease significantly the radar cross section, without severe reduction of the frigate speed. [less ▲]

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See detailFeasibility-oriented Branching Strategies for Global Optimization
Gerard, Damien ULg; Köppe, Matthias; Louveaux, Quentin ULg

E-print/Working paper (2016)

We study the spatial Brand-and-Bound algorithm for the global optimization of nonlinear problems. In particular we are interested in a method to find quickly good feasible solutions. Most spatial Branch ... [more ▼]

We study the spatial Brand-and-Bound algorithm for the global optimization of nonlinear problems. In particular we are interested in a method to find quickly good feasible solutions. Most spatial Branch-and-Bound-based solvers use a non global solver at a few nodes to try to find better incumbents. We show that it is possible to improve the branching rules and the node priority by exploiting the solutions from the non global solver. We also propose several smart adaptive strategies to choose when to run the non global solver. We show that despite the time spent in solving many more NLP problems in the nodes, the new strategies enable the algorithm to find the first good incumbents faster and to prove the global optimality faster. Numerous easy, medium size as well as hard NLP instances from the Coconut library are benchmarked. All experiments are run using the open source solver Couenne. [less ▲]

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See detailFeasibility-oriented Branching Strategies for Global Optimization
Gerard, Damien ULg; Köppe, Matthias; Louveaux, Quentin ULg

Conference (2015, July 13)

We study the spatial Brand-and-Bound algorithm for the global optimization of nonlinear problems. In particular we are interested in a method to find quickly good feasible solutions. Most spatial Branch ... [more ▼]

We study the spatial Brand-and-Bound algorithm for the global optimization of nonlinear problems. In particular we are interested in a method to find quickly good feasible solutions. Most spatial Branch-and-Bound-based solvers use a non global solver at a few nodes to try to find better incumbents. We show that it is possible to improve the branching rules and the nodes priority by exploiting the solutions from the non global solver. We also propose several smart adaptive strategies to choose when to run the non global solver. We show that despite the time spent in solving many more NLP problems in the nodes, the new strategies enable the algorithm to find the first good incumbents much faster and to prove the global optimality faster. NLP instances from the COCONUT library are benchmarked. All experiments are run using the open source solver Couenne. [less ▲]

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See detailFeast or famine: the global regulator DasR links nutrient stress to antibiotic production by Streptomyces
Rigali, Sébastien ULg; Titgemeyer, Fritz; Barends, Sharief et al

in EMBO Reports (2008), 9(7), 670-675

Members of the soil-dwelling prokaryotic genus Streptomyces produce a wealth of secondary metabolites, including antibiotics and anti-tumour agents. Their formation is intimately coupled with the onset of ... [more ▼]

Members of the soil-dwelling prokaryotic genus Streptomyces produce a wealth of secondary metabolites, including antibiotics and anti-tumour agents. Their formation is intimately coupled with the onset of development, triggered by the nutrient status of the habitat. We propose the first complete signalling cascade from nutrient sensing to development and antibiotic biosynthesis. We show that a high concentration of N-acetylglucosamine - perhaps mimicking the accumulation of N-acetylglucosamine after autolytic degradation of the vegetative mycelium - is a major checkpoint for the onset of secondary metabolism. The response is transmitted to the antibiotic pathway-specific activators via the pleiotropic transcriptional repressor DasR, whose regulon also includes all N-acetylglucosamine-related catabolic genes. The results have led to a new strategy for activating “cryptic” pathways for secondary metabolite biosynthesis, which are abundant in actinomycete genomes, thereby offering new prospects in the fight against multiply drug resistant pathogens and cancers. [less ▲]

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See detailFeature extraction for non-linear model updating
Kerschen, Gaëtan ULg; Golinval, Jean-Claude ULg

in International Conference on Structural Dynamics Modelling, Funchal, 2002 (2002, June)

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See detailFeature Extraction from Range Imagery using Mathematical Morphology
Esselman, Thomas R.; Verly, Jacques ULg

Conference (1987, October)

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See detailFeature Extraction in Laser-radar Range Imagery: I. Contour-based Approach
Williams, Brian D.; Verly, Jacques ULg; Esselman, Thomas R. et al

Conference (1986, November)

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See detailFeature Extraction in Laser-radar Range Imagery: II. Intensity-Cued Region-based Approach
Verly, Jacques ULg; Esselman, Thomas R.; Dudgeon, Dan E.

Conference (1986, November)

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See detailFeature extraction using auto-associative neural networks
Kerschen, Gaëtan ULg; Golinval, Jean-Claude ULg

in Smart Materials & Structures (2004), 13(1), 211-219

Modal analysis is now mature and well accepted in the design of mechanical structures. It determines the vibration mode shapes and the corresponding natural frequencies. However, the validity of modal ... [more ▼]

Modal analysis is now mature and well accepted in the design of mechanical structures. It determines the vibration mode shapes and the corresponding natural frequencies. However, the validity of modal analysis is limited to structures showing a linear behaviour. In non-linear structural dynamics, it is well known that mode shapes are no longer useful for the characterization of the dynamic response. The purpose of the present paper is to define new features which efficiently capture the dynamics of a non-linear structure. The proposed methodology takes advantage of auto-associative neural networks to compute one-dimensional curves which allow for non-linear dependences between the coordinates. Synthetic data sampled from a non-linear normal mode motion are used to illustrate the method and to develop intuition about its implementation. [less ▲]

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See detailFeature issue of digital holography and 3D imaging (DH): introduction
Hayasaki, Yoshio; Liu, Jung-Ping; Georges, Marc ULg

in Applied Optics (2015), 54(1), 1-2

The OSA Topical Meeting “Digital Holography and 3D Imaging (DH)” was held in Seattle, Washington, 13–17 July 2014. Feature issues based on the DH meeting series have been released by Applied Optics (AO ... [more ▼]

The OSA Topical Meeting “Digital Holography and 3D Imaging (DH)” was held in Seattle, Washington, 13–17 July 2014. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. In this year (2014), Optics Express (OE) and AO jointly decided to have one such feature issue in each journal. The feature issue includes 27 papers and covers a large range of topics, reflecting the rapidly expanding techniques and applications of digital holography and 3D imaging. The DH meeting will continue in the future, as expected, and the next meeting is scheduled to be held on24–28 May 2015, at Shanghai Institute of Optics and Fine Mechanics, Shanghai, China. [less ▲]

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See detailFeature Selection and Extraction
Verly, Jacques ULg

Scientific conference (1998)

Detailed reference viewed: 7 (1 ULg)