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
Peer Reviewed
See detailFunctional Templates and Their Applications to 3-D Object Recognition
Delanoy, Richard L.; Verly, Jacques ULg; Dudgeon, Dan E.

Conference (1992, March)

Detailed reference viewed: 3 (0 ULg)
Full Text
Peer Reviewed
See detailA functional test procedure for the improved commissioning of a VAV system
Andre, Philippe ULg; Lacôte, P.; Aparecida Silva, Cl. et al

Conference (2004, October)

In the context of the IEA40 research project, a specification of a “Functional Test Procedure” was progressively developed using the CA-MET building in Namur as real size test bench for the application ... [more ▼]

In the context of the IEA40 research project, a specification of a “Functional Test Procedure” was progressively developed using the CA-MET building in Namur as real size test bench for the application and validation of the procedure. The target system is a typical VAV system devoted to the ventilation, cooling and air conditioning functions. The procedure consists in a series of operations to be applied to the system, considered as a set of connected components and taking into account the following constraints: - time availability - intrinsic limitations of the system - reference performances The proposed procedure is divided in two sets of actions: - a number of preliminary actions allowing to take the best benefit of the subsequent phases: o identification of available measurement points o identification of actuators characteristics o identification of control strategies o aeraulic network calculations o selection of measurement techniques and experimental design - the verification tasks themselves: The philosophy of the verification process is to bring the system into a number of states whoch allowed each specific checks to be carried out. The organisation of the procedure tries to optimize the time spent for commissioning by logically sequencing the operations according to the following order: - test in manual operation - test in manual stop - test in normal operation - test at maximum flowrate - test at minimum flowrate - test in automatic stop The paper will provide the specific operations to be carried out at each step and will illustrate the whole process with the prototyping work performed on the CA-MET building in Namur. [less ▲]

Detailed reference viewed: 16 (1 ULg)
Full Text
Peer Reviewed
See detailFunctional traits are weak predictors of tree sapling growth worldwide
Paine, C. E. Timothy; Auge, Harald; Baraloto, Christopher et al

Conference (2013, June 26)

Functional traits, well-defined characteristics of organisms that influence or coordinate with ecological performance, promise that one may predict vital rates, such as survival and growth, by measuring a ... [more ▼]

Functional traits, well-defined characteristics of organisms that influence or coordinate with ecological performance, promise that one may predict vital rates, such as survival and growth, by measuring a few aspects of anatomy and physiology. Functional traits have been shown to correlate significantly, though weakly, with the relative growth rate (RGR) of trees in five Neotropical forests. Here, we estimated size-standardized height RGR for 26344 saplings of 240 species from 23 sites around the world using nonlinear models of growth. We then predicted the contribution of three functional traits (specific leaf area, wood density and seed mass) to individual RGR with a hierarchical Bayesian model. The three functional traits, alone and in combination, explained a relatively small amount of variance in RGR, with variation among continents and between temperate and tropical regions. We echo the calls for researchers to shift toward the measurement of 'hard' functional traits, with clear linkages to realized vital rates, rather than 'soft' functional traits, which are easier to measure but may only indicate the theoretical maxima of vital rates. Doing so would advance ecology onto a more solidly functional foundation. [less ▲]

Detailed reference viewed: 23 (7 ULg)
Full Text
Peer Reviewed
See detailA functional variant of lymphoid tyrosine phosphatase is associated with type I diabetes.
Bottini, Nunzio; Musumeci, Lucia; Alonso, Andres et al

in Nature Genetics (2004), 36(4), 337-8

We report that a single-nucleotide polymorphism (SNP) in the gene (PTPN22) encoding the lymphoid protein tyrosine phosphatase (LYP), a suppressor of T-cell activation, is associated with type 1 diabetes ... [more ▼]

We report that a single-nucleotide polymorphism (SNP) in the gene (PTPN22) encoding the lymphoid protein tyrosine phosphatase (LYP), a suppressor of T-cell activation, is associated with type 1 diabetes mellitus (T1D). The variants encoded by the two alleles, 1858C and 1858T, differ in a crucial amino acid residue involved in association of LYP with the negative regulatory kinase Csk. Unlike the variant encoded by the more common allele 1858C, the variant associated with T1D does not bind Csk. [less ▲]

Detailed reference viewed: 27 (8 ULg)
Full Text
Peer Reviewed
See detailFunctional, inflammatory and morphological characterisation of a cat model of allergic airway inflammation
Kirschvink, N.; Leemans, Jérôme ULg; Delvaux, François et al

in Veterinary Journal (2007), 174(3), 541-553

The aims of this study were to characterise a model of feline allergic airway inflammation and to test through a longitudinal investigation whether five repeated allergen exposures would lead to signs of ... [more ▼]

The aims of this study were to characterise a model of feline allergic airway inflammation and to test through a longitudinal investigation whether five repeated allergen exposures would lead to signs of airway remodelling that would be detectable in vivo. Eight healthy control cats and eight cats sensitised with Ascaris suum allergens were investigated. Barometric whole body plethysmography (BWBP) was used for the assessment of respiratory variables and airway responsiveness (AR). Bronchoalveolar lavage fluid (BALF) was sampled for cytology and determination of F-2-isoprostane concentration and matrix metalloproteinase type 9 (MMP-9) activity. Thoracic radiography and bronchoscopy scores were also established. Cats were investigated prior to sensitisation and after inhalation of placebo or allergen challenge 1. BWBP measurements revealed a significant increase of enhanced pause (Penh), an index of bronchoconstriction, and AR in sensitised cats in response to allergen challenge 1. A significant increase in BALF neutrophil and eosinophil %, F-2-isoprostane concentration and MMP-9 activity, and increased radiography and bronchoscopy scores were recorded. After a recovery period of 6 weeks, all variables except BALF MMP-9 returned to baseline values. Four further allergen challenges induced similar changes to those seen in challenge I and no signs of persistent changes suggestive of bronchial remodelling were detectable. The model provides an in vivo approach to functional, inflammatory and morphological changes occurring in response to single and repeated allergen exposure. [less ▲]

Detailed reference viewed: 24 (4 ULg)
Full Text
Peer Reviewed
See detailFunctionalisation and chemical characterisation of cellulose derived carbon aerogels
Grzyb, Bartosz; Hildenbrand, Claudia; Berthon-Fabry, Sandrine et al

in Carbon (2010), 48

Detailed reference viewed: 35 (2 ULg)
Full Text
Peer Reviewed
See detailFunctionality in single-molecule devices: Model calculations and applications of the inelastic electron tunneling signal in molecular junctions
Dash, Louise K; Ness, Hervé; Verstraete, Matthieu ULg et al

in Journal of Chemical Physics (2012), 136

We analyze how functionality could be obtained within single-molecule devices by using a combination of non-equilibrium Green's functions and ab initio calculations to study the inelastic transport ... [more ▼]

We analyze how functionality could be obtained within single-molecule devices by using a combination of non-equilibrium Green's functions and ab initio calculations to study the inelastic transport properties of single-molecule junctions. First, we apply a full non-equilibrium Green's function technique to a model system with electron-vibration coupling. We show that the features in the inelastic electron tunneling spectra (IETS) of the molecular junctions are virtually independent of the nature of the molecule-lead contacts. Since the contacts are not easily reproducible from one device to another, this is a very useful property. The IETS signal is much more robust versus modifications at the contacts and hence can be used to build functional nanodevices. Second, we consider a realistic model of a organic conjugated molecule. We use ab initio calculations to study how the vibronic properties of the molecule can be controlled by an external electric field which acts as a gate voltage. The control, through the gate voltage, of the vibron frequencies and (more importantly) of the electron-vibron coupling enables the construction of functionality: nonlinear amplification and/or switching is obtained from the IETS signal within a single-molecule device. [less ▲]

Detailed reference viewed: 22 (2 ULg)
Full Text
Peer Reviewed
See detailFUNCTIONALITY OF SYNTHETIC POLYCATIONS FOR THE MASKING OF ANTIGENIC SITES BY MEANS OF OPTICAL METHODS
Relancio, MF; Riquelme, B; Dumas, D et al

in Proceeding of the 91st Annual Meeting of the Argentine Physics Association (2006)

Detailed reference viewed: 6 (0 ULg)
See detailFunctionalization of AFM tips by electrografting
Jérôme, Christine ULg; Willet, Nicolas ULg; Gabriel, Sabine ULg et al

Poster (2003, May 16)

Detailed reference viewed: 18 (3 ULg)
Full Text
See detailFunctionalization of aliphatic polyesters by “click chemistry” in supercritical carbon dioxide
Grignard, Bruno ULg; Schmeits, Stephanie ULg; Riva, Raphaël ULg et al

Poster (2009, May 14)

The combination of ring-opening polymerization of lactones and “click” copper-catalyzed Huisgen’s [3+2] cycloaddition is known to be a very efficient strategy for the functionalization of poly(ε ... [more ▼]

The combination of ring-opening polymerization of lactones and “click” copper-catalyzed Huisgen’s [3+2] cycloaddition is known to be a very efficient strategy for the functionalization of poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA). Whenever the “click” reaction occurs in an organic solvent (THF or DMF), at relatively low temperature (35°C) and within short reaction time (2 hours), no significant degradation of polyester chains is detected. This strategy was implemented in previous works to graft alkynes substituted by different functional groups, such as hydroxyl, tertiary amines, acrylates or ammonium salts onto azide-functionalized PCL. Moreover, this approach was previously extended to the synthesis of grafted copolymers, either by the grafting of omega-alkyne-PEO onto azide-functionalized aliphatic PLA or PCL (“grafting onto” technique) either by grafting of an ATRP initiator followed by the polymerization of vinyl monomers, such as styrene (“grafting from” technique). These functionalized aliphatic polyesters are promising materials for the development of new biomedical devices. In this work, novel conditions were implemented for the “click” reaction in order to avoid the use of organic solvents and to limit the amount of catalyst remnants in functionalized aliphatic polyesters. Toward this end, if was found that the functionalization by “click” chemistry can be efficiently carried out in supercritical carbon dioxide rather than in THF or DMF. For that sake, it turned out necessary to synthesize a perfluorinated polyamine in order to solubilize the catalyst in supercritical carbon dioxide. Aliphatic polyesters are not soluble in supercritical carbon dioxide. Nevertheless, even under heterogeneous conditions, the functionalization of aliphatic polyesters by “click” chemistry is quantitative. Interestingly enough, no degradation was observed. Last but not least, the copper catalyst was easily removed by supercritical fluid extraction leading to a very low content of residual copper in the final copolyester. [less ▲]

Detailed reference viewed: 128 (16 ULg)
See detailFunctionalization of carbon nanotubes by polymers using grafting to methods
Thomassin, Jean-Michel ULg; Jérôme, Robert ULg; Jérôme, Christine ULg et al

in Mittal, Vikas (Ed.) Surface modification of nanotube fillers (2011)

The huge research effort devoted to the chemical modification of CNTs by grafted macromolecules is driven by the need to enhance their affinity for a variety of environments, a necessary step for ... [more ▼]

The huge research effort devoted to the chemical modification of CNTs by grafted macromolecules is driven by the need to enhance their affinity for a variety of environments, a necessary step for designing advanced nanomaterials. This chapter aims at reviewing the until now investigated “grafting to” methods used for the surface modification of carbon nanotubes (CNTs) by polymers of various functionalities. Two major strategies are emphasized on the basis of the number of needed modification steps. The first technique consists in functionalizing the CNTs surface to promote in a second step the covalent anchoring of polymer chains bearing complementary reactive groups either at one chain-end or along the chain. The second approach is straightforward as result of the ability of the selected polymer to add directly onto the sp2 carbons of the CNTs surface. The major advantage of the “grafting onto” techniques is that the molecular characteristics (molecular weight, polydispersity, functionality,…) of the polymers can be tailored prior to the grafting reaction. Moreover, when using the proper controlled or living polymerization techniques and grafting conditions, polymers of well-defined architecture, functionality and properties can be easily anchored to the CNTs surface, which makes the “on-demand” tuning of the chemical properties of CNTs possible. [less ▲]

Detailed reference viewed: 56 (5 ULg)
Full Text
Peer Reviewed
See detailFunctionalization of carbon xerogels for the preparation of palladium supported catalysts applied in sugar transformations
Mager, Nathalie; Meyer, Nathalie; Léonard, Alexandre ULg et al

in Applied Catalysis B : Environmental (2014), 148-149

Detailed reference viewed: 48 (6 ULg)
Peer Reviewed
See detailFunctionalization of carbon xerogels for the preparation of Pd/C catalysts by grafting of Pd complex
Diverchy, C.; Hermans, S.; Job, Nathalie ULg et al

Poster (2010, July 11)

Detailed reference viewed: 9 (0 ULg)
Full Text
Peer Reviewed
See detailFunctionalization of carbon xerogels for the preparation of Pd/C catalysts by grafting of Pd complex
Diverchy, Chantal; Hermans, Sophie; Job, Nathalie ULg et al

in Studies in Surface Science and Catalysis (2010), 175

Detailed reference viewed: 21 (1 ULg)
Full Text
Peer Reviewed
See detailFunctionalization of multi-walled carbon nanotubes by electrografting of polyacrylonitrile
Petrov, Petar; Lou, Xudong; Pagnoulle, Christophe et al

in Macromolecular Rapid Communications (2004), 25(10), 987-990

As a result of their unique architecture and remarkable mechanical and electrical properties[1,2] carbon nanotubes (CNTs)[3] have great potential that remains, however, un-exploited because of poor ... [more ▼]

As a result of their unique architecture and remarkable mechanical and electrical properties[1,2] carbon nanotubes (CNTs)[3] have great potential that remains, however, un-exploited because of poor dispersibility in liquids and problems of processability, Major efforts have, therefore, been devoted towards any modification of the CNTs that could improve their handling[4,5] Typically, chemical modification of CNTs is based on severe oxidation processes that often damage the tubes[5] Mild and single-step electrochemical modification of CNTs is a valuable alternative to the oxidative treatment. There are several reports in the scientific literature on the electrochemical functionalization of CNTs by electroreduction of diazonium salts,[6-8] and on the halogenation of MWNTs by electrolysis However, the grafting of polymers instead of low-molecular-weight compounds onto CNTs by an electrochemical process is a possible strategy for dispersing CNTs in polymer matrices and improving the mechanical properties of CNT-based nanocomposites.. For the past few years, we have been interested in the electiografting of insulating polymer films onto cathodic surfaces, for example, nickel and glassy carbon, provided that the potential and solvent are properly selected.[10-15] These films are designated as "grafted films", because they have the unique property of remaining attached to the electrode surface even when they are prepared and kept in a solvent in which the polymer is highly soluble. The extension of this technique to CNTs has been explored with acrylonitrile as monomer. This communication aims at reporting the functionaliza-tion of multi-walled carbon nanotubes (MWNTs) by the electropolymerization of acrylonitrile. [less ▲]

Detailed reference viewed: 27 (4 ULg)
Full Text
Peer Reviewed
See detailFunctionalization of poly(epsilon-caprolactone) by pendant hydroxyl, carboxylic acid and epoxide groups by atom transfer radical addition
Riva, Raphaël ULg; Lenoir, Sandrine ULg; Jérôme, Robert ULg et al

in Polymer (2005), 46(19), 8511-8518

A straightforward strategy is proposed for grafting hydroxyl, carboxylic acid and epoxide groups along poly (epsilon-caprolactone) chains. Statistical copolymerization of epsilon-caprolactone (epsilon-CL ... [more ▼]

A straightforward strategy is proposed for grafting hydroxyl, carboxylic acid and epoxide groups along poly (epsilon-caprolactone) chains. Statistical copolymerization of epsilon-caprolactone (epsilon-CL) with alpha-chloro-epsilon-caprolactone (alpha-Cl-epsilon-CL) has been initiated by 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP), followed by the atom transfer radical addition (ATRA) of but-3-en-1-ol, vinylacetic acid and 1,2-epoxyhex-5-ene, respectively, onto the alpha-chloro units of a poly(alpha-Cl-epsilon-CL-co-epsilon-CL) copolymer. alpha-Cl-epsilon-CL is easily prepared by the Baeyer-Villiger oxidation of 2-chlorocyclohexanone. The influence of the experimental conditions, i.e. temperature, solvent, catalyst, on the grafting yield has been discussed. Because ATRA is tolerant of the investigated functional groups, no protection/deprotection reaction is required, which is a major advantage of the method. [less ▲]

Detailed reference viewed: 54 (5 ULg)
Full Text
See detailFunctionalization of poly(ε-caprolactone) and its macromolecular engineering
Riva, Raphaël ULg

Doctoral thesis (2007)

Macromolecular engineering is one of the most powerful tools to control the molecular parameters, including architecture of polymers, and to improve their performances or to impart them new properties ... [more ▼]

Macromolecular engineering is one of the most powerful tools to control the molecular parameters, including architecture of polymers, and to improve their performances or to impart them new properties. This contribution aims at reporting on a novel strategy for the macromolecular engineering of poly-ε-caprolactone (PCL) which is based on the use of functional ε-caprolactone, the α-chloro-ε-caprolactone (αClεCL). Indeed, αClεCL is a precursor of polymers and copolymers with εCL that bear pendant activated chlorides well suited to “grafting from” reaction. These (co)polyesters have been used as macroinitiators for the Atom Transfer Radical Polymerization (ATRP) of methyl methacrylate leading to the corresponding graft copolymer. They have also been involved in an Atom Transfer Radical Addition (ATRA) reaction with a series of olefins bearing different functional groups (hydroxyl, carboxylic acid and epoxy group) in order to functionalize the polyester backbone without deleterious degradation. ATRA of PEO chains with an unsaturation end groups has also been carried out in order to prepare PCL-g-PEO of different compositions to be used as stabilizers of polyester nanoparticles. Combination of ring-opening polymerization of ε-caprolactone and the copper-catalyzed Huisgen’s [3+2] cycloaddition is a novel strategy for going a step further in the macromolecular engineering of poly-ε-caprolactone (PCL). This ‘click” reaction is very well-suited to the chemical modification of aliphatic polyesters because, its implementation under very mild conditions prevents chain degradation from occurring. Indeed, alkynes were cycloadded onto azide containing PCL at low temperature (35°C) in an organic solvent (DMF or THF). Originally, α-chloro-ε-caprolactone and ε-caprolactone were randomly copolymerized in toluene at room temperature followed by reaction of the activated chlorides with sodium azide. In order to make a wide range of functional aliphatic polyesters available, poly(α-azide-ε-caprolactone-co-ε-caprolactone) copolyesters were reacted with a series of alkynes substituted by a functional group, e.g., hydroxyl, acrylate and quaternary ammonium salts, This strategy turned out to be efficient to synthesize for instance hydrophilic, photo-cross-linkable and hydrosoluble PCL. Moreover, a variety of graft copolymers were prepared by both the “grafting from” and the “grafting onto” techniques. Indeed, an ATRP initiator was attached onto PCL followed by polymerization of vinyl monomers, whereas alkyne end–capped PEO was cycloadded onto azide-containing PCL with formation of amphiphilic PCL-g-PEO copolymers. Last but not least, the “click” chemistry was very instrumental in imparting an antimicrobial activity to PCL or for the preparation of new functionalized caprolactones. [less ▲]

Detailed reference viewed: 147 (92 ULg)
See detailFunctionalization of traditional biodegradable polyesters
Detrembleur, Christophe ULg

Conference (2001, July 15)

Detailed reference viewed: 5 (0 ULg)