Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
See detailDéserts, poussières et migrations
Ozer, Pierre ULg

Article for general public (2006)

Chaque année, le Sahara injecte près d'un milliard de tonnes de poussières dans l'atmosphère. Plus de 100 millions de tonnes de ces poussières prennent la direction de l'Europe. Beaucoup d'entre elles se ... [more ▼]

Chaque année, le Sahara injecte près d'un milliard de tonnes de poussières dans l'atmosphère. Plus de 100 millions de tonnes de ces poussières prennent la direction de l'Europe. Beaucoup d'entre elles se perdent dans la Méditerranée avant d'atteindre le Vieux Continent. D'autres retombent au gré des pluies et recouvrent périodiquement nos véhicules. Elles constituent un véritable problème de santé publique dans le sud de l'Europe, comme en Espagne, car l'importante concentration de ces fines particules dégrade la qualité de l'air que nous respirons. Certes, ce phénomène a toujours existé. Mais il a très fortement augmenté depuis les années 1980, depuis que les zones péridésertiques sont sujettes aux processus de plus en plus pressants de désertification. La végétation ayant disparu sur des centaines de millions d'hectares, de nouveaux sols ont été emportés par le vent. [...] [less ▲]

Detailed reference viewed: 452 (51 ULg)
See detailLe désherbage mécanique, une technique d'avenir
Dardenne, J.; Dewez, G.; Vandersmissen, P. et al

in Revue de l’Agriculture = Landbouwtijdschrift (1992), 45(6), 1193-1200

Detailed reference viewed: 15 (1 ULg)
See detailDesiccation-tolerance : an advantage for the biotechnological applications of bacteria
Weekers, F.; Jacques, Ph.; Springael, D. et al

Poster (1999, July)

Detailed reference viewed: 17 (0 ULg)
Peer Reviewed
See detailDesign aids for the design of steel moment connections
Jaspart, Jean-Pierre ULg

in Proceedings of the 5th International Colloquium on Stability of Metal Structures (1996)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailDesign and analysis of an SOI MEMS voltage step-up converter
Gleeson, R.; Kraft, Michaël ULg; White, N. M.

in Journal of Micromechanics and Microengineering (2013), 23(11), 114017

Detailed reference viewed: 7 (0 ULg)
Peer Reviewed
See detailDesign and characterization of novel forms of human 16K prolactin, an antiangiogenic factor
Mainfroid, Véronique; Struman, Ingrid ULg; Weiner, Richard I. et al

Poster (1998, January)

Detailed reference viewed: 6 (0 ULg)
Full Text
See detailDesign and development of new polyamides by ring-opening polymerization for high performance composite materials
Tunc, Deniz; Carlotti, Stéphane; Lecomte, Philippe ULg et al

Poster (2013, May 16)

Detailed reference viewed: 57 (5 ULg)
Full Text
Peer Reviewed
See detailDesign and dimensioning of hydrogen transmission pipeline networks
de Wolf, Daniel ULg

in European Journal of Operational Research (2013), 229(1), 239-251

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailDesign and evaluation of a semantic enrichment process for bibliographic databases
Lacasta, Javier; Nogueras-Iso, Javier; Falquet, Gilles et al

in Data & Knowledge Engineering (2013), 88

The limited semantics of thesauri and similar knowledge models hinder the searching and browsing possibilities of the bibliographic databases classified with this type of resources. This work proposes an ... [more ▼]

The limited semantics of thesauri and similar knowledge models hinder the searching and browsing possibilities of the bibliographic databases classified with this type of resources. This work proposes an automatic process to convert a knowledge model into a domain ontology through the alignment with DOLCE, an upper level ontology. This process is facilitated by an intermediary alignment with Wordnet, a lexical model. The process has been tested with the thesauri and bibliographic databases of Urbamet and the European Urban Knowledge Network. The Urbamet model has been used to create an atlas of urban related resources with advanced search capabilities. [less ▲]

Detailed reference viewed: 32 (7 ULg)
Full Text
See detailDesign and evaluation of new hydrogels for biomaterial purposes
Grandfils, Christian ULg; Barakat, I; Fairon, N et al

Conference (2003, October 23)

Detailed reference viewed: 5 (1 ULg)
Full Text
See detailDesign and evaluation of new reinforced hydrogel membranes for biomaterial purposes
Fairon, N; Grandfils, Christian ULg; Barakat, I et al

Poster (2003, October 23)

Detailed reference viewed: 9 (1 ULg)
Full Text
Peer Reviewed
See detailDesign and Experimental investigation of a Small scale organic Rankine using a scroll expander
Declaye, Sébastien ULg; Quoilin, Sylvain ULg; Lemort, Vincent ULg

in Proceeding of the 13th International Refrigeration and Air Conditioning Conference at Purdue (2010, July 11)

The world is facing a historical increase in energy demand and energy consumption. As consequence the conventional fossil fuels are depleting faster with an inherent pollution causing sever damages to our ... [more ▼]

The world is facing a historical increase in energy demand and energy consumption. As consequence the conventional fossil fuels are depleting faster with an inherent pollution causing sever damages to our environment. Renewable energy sources are considered as a solution to both environmental issue and energy demand. At the same time a lot of waste heat is witnessed in processes in industries and other thermal devices such internal combustion engines. Our objective is to propose a solution to recover this heat wasted. The organic Rankine cycle appeared to us as a solution. This paper presents a study carried out on a prototype of small scale organic Rankine cycle (ORC) driven by two waste heat hot air streams. The prototype was designed using a diaphragm pump, a set of plate heat exchangers and an oil-free scroll compressor adapted to run in expander mode. The available literature on Organic Rankine Cycles only proposes theoretical studies of fluid selection for a given application. This study aims at comparing fluids experimentally. Therefore, several fluids (including R245fa and R123) were tested in the prototype and the performance was measured. The tests were performed to study the performance of the ORC system and the expander over a wide range of working conditions. The temperature of the heat sources varied between 150°C and 200°C. The maximum expander shaft power was above 2kW and maximum expander efficiency was 70%. These tests allowed to point out the critical characteristics that should be taken into account while selecting the components for the design of an ORC. [less ▲]

Detailed reference viewed: 409 (30 ULg)
Full Text
See detailDesign and fabrication of a variable wall thickness two-stage scroll expander to be integrated in a micro-solar power plant
Dickes, Rémi ULg

Master's dissertation (2013)

Improving access to energy in developing countries without exacerbating climate change requires novel technical strategies. MicroCSP power plants using organic Rankine cycles (ORCs) are one example of a ... [more ▼]

Improving access to energy in developing countries without exacerbating climate change requires novel technical strategies. MicroCSP power plants using organic Rankine cycles (ORCs) are one example of a promising approach for meeting this challenge. Specifically, expander development has been identified as a critical component for enhancing the performances of small ORC units. The goal of this project is to develop an optimized two-stage scroll expander to be integrated in a MicroCSP power plant designed to supply remote, off-grid areas. The expansion requirements are firstly defined so as to meet production specifications. Then, employing a deterministic model and a selection process, optimal scroll geometries are chosen for both expansion stages. The deterministic model is executed with Matlab and accounts for the relevant physical phenomena i.e. radial and flank leakages, throttling losses at the intake and exhaust processes, friction between the two scrolls and mechanical losses in the different bearings. A performance enhancement of about 6\% of the isentropic efficiency is predicted in comparison with baseline practice. A CAD model of a single-stage prototype is developed in Solidworks following the main architectural features of a compliant HVAC scroll compressor. This CAD is updated and improved with the optimal scroll geometries and some parts are 3D printed to verify their mechanical assembly. Toolpaths to control CNC machines are generated using the CAM program HSMXpress and the parts constituting the expander prototype are manufactured in a machine shop. In conclusion, the properties of the enhanced scroll expander are evaluated in the context of a typical Micro-CSP plant. A simple steady state model in EES is developed to quantify how three parameters (T_ev, T_cond and eta_exp) influence the power plant overall sunlight to electricity conversion efficiency (a gain of 0.73% is predicted). This project underscores the importance of optimizing the expansion process and identifies further research pathways to progress towards this goal. [less ▲]

Detailed reference viewed: 181 (33 ULg)
Full Text
Peer Reviewed
See detailDesign and fabrication of an electrode array sensor for probing the electric potential distribution at the mesoscopic scale in antistatic felts
Boutaayamou, Mohamed ULg; Lemaire, Philippe; Vanderheyden, Benoît ULg et al

in Measurement Science and Technology (2014), 25

We present an original voltage probe design for measuring the electric potential distribution at the mesoscopic scale (i.e., 1 mm–1 cm) in antistatic felts. The felts are composed of a mixture of non ... [more ▼]

We present an original voltage probe design for measuring the electric potential distribution at the mesoscopic scale (i.e., 1 mm–1 cm) in antistatic felts. The felts are composed of a mixture of non-conductive and metallic fibers and exhibit complex nonlinear electric behavior—including possibly nonlinearity and hysteresis effects—which may be due to localized electrical or electromechanical phenomena. The sensor consists of an array of 8 × 9 needle electrodes (phgr 160 µm at the shaft and less than phgr 50 µm toward the apex), which are mechanically maintained at fixed relative positions while their tips are inserted inside the fabric of the sample. The interelectrode distance is 1.5 mm and the overall active area is 12 × 12 mm². The electrical insulation resistance for nearest neighbor pairs of electrodes was found to be larger than 860 GΩ, thus making the sensor suitable for measuring antistatic felts with an electric resistance that typically does not exceed a few GΩ. The sensor was successfully used for measuring the distribution of the electric potential in a polyester fabric subjected to voltages of up to 6.2 kV, and in a sample containing 2% in weight of metallic fibers, demonstrating the presence of irreversible changes in that felt sample (i.e., with conductive fibers) at high voltages. It is concluded that the developed probe voltage is a promising technique that could be used for the assessment of the conduction mechanisms in the antistatic materials at the mesoscopic scale. [less ▲]

Detailed reference viewed: 45 (19 ULg)
Full Text
See detailDesign and Implementation of a Distributed Lattice Boltzmann-based Fluid Flow Simulation Tool
Dethier, Gérard ULg

Doctoral thesis (2011)

Lattice Boltzmann-based (LB) simulations are well suited to the simulation of fluid flows in complex structures encountered in chemical engineering like porous media or structured packing used in ... [more ▼]

Lattice Boltzmann-based (LB) simulations are well suited to the simulation of fluid flows in complex structures encountered in chemical engineering like porous media or structured packing used in distillation and reactive distillation columns. These simulations require large amounts of memory (around 10 gigabytes) and would require very long execution times (around 2 years) if executed on a single powerful desktop computer. The execution of LB simulations in a distributed way (for example, using cluster computing) can decrease the execution time and reduces the memory requirements for each computer. Dynamic Heterogeneous Clusters (DHC) is a class of clusters involving computers inter-connected by a local area network; these computers are potentially unreliable and do not share the same architecture, operating system, computational power, etc. However, DHCs are easy to setup and extend, and are made of affordable computers. The design and development of a software system which organizes large scale DHCs in an efficient, scalable and robust way for implementing very large scale LB simulations is challenging. In order to avoid that some computers are overloaded and slow down the overall execution, the heterogeneity of computational power should be taken into account. In addition, the failure of one or several computers during the execution of a simulation should not prevent its completion. In the context of this thesis, a simulation tool called LaBoGrid was designed. It uses existing static load balancing tools and implements an original dynamic load balancing method in order to distribute the simulation in a way that minimizes its execution time. In addition, a distributed and scalable fault-tolerance mechanism based on the regular saving of simulation’s state is proposed. Finally, LaBoGrid is based on a distributed master-slave model that is robust and potentially scalable. [less ▲]

Detailed reference viewed: 262 (56 ULg)