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 detailElectroinitiated polymerization
Jérôme, Christine ULg

in Matyjaszewski, Krzysztof; Möller, Martin (Eds.) Polymer Science: a comprehensive reference ; volume 4: Ring-Opening Polymerization and Special Polymerization Processes (2012)

Electroinitiated polymerization, a method particularly relevant in coating technology, offers the unique opportunity of imparting permanent functionality/reactivity to a variety of surfaces, provided that ... [more ▼]

Electroinitiated polymerization, a method particularly relevant in coating technology, offers the unique opportunity of imparting permanent functionality/reactivity to a variety of surfaces, provided that the solid substrate is (semi)conducting. By focusing on the electroinitiation of acrylic monomers, basic concepts and some tools dedicated to the analysis of this peculiar polymerization process are discussed in this chapter. The important role of this polymerization method in the field of conjugated polymers is also highlighted. Finally, this chapter concludes with the opportunities and future challenges of this technology. [less ▲]

Detailed reference viewed: 13 (3 ULg)
See detailELECTROKINETIC CHARACTERIZATION OF IMMOBILIZED ASPERGILLUS-NIGER BETA GALACTOSIDASE
Paquot, Michel ULg; LESAGE, V.

in Belgian Journal of Food Chemistry and Biotechnology (1986), 41(6), 161-165

Microcrystalline cellulose was activated with diphenylmethane 4,4-diisocyanate and triethylamine and was used to immobilize beta-galactosidase (beta-Gal) at 4 or 20C and pH 3.6 or 4.6. The activation ... [more ▼]

Microcrystalline cellulose was activated with diphenylmethane 4,4-diisocyanate and triethylamine and was used to immobilize beta-galactosidase (beta-Gal) at 4 or 20C and pH 3.6 or 4.6. The activation procedure modified the electrokinetic characteristics of the carrier, making the zeta potential less negative; at pH below 4.5 the zeta potential became positive. Immobilization of beta-Gal shifted the isoelectric point to acid pH. Conditions to produce the highest residual beta-Gal activity were pH 4.6 and temp. of 4C. Addition of 1250 p.p.m. NaCl, CaCl2 or Ca(NO3)2 at the optimum pH decreased beta-Gal activity, effects being greater for the immobilized enzyme than for free enzyme. Optimum pH after immobilization was increased by approx. one unit by Ca salts, while Na had no effect. Ca(NO3)2 caused a shift of zeta potential to more positive values and the isoelectric point of the immobilized enzyme to alkaline pH. Na had less influence on zeta potential but at 50 p.p.m. did displace the isoelectric point. [less ▲]

Detailed reference viewed: 51 (0 ULg)
Full Text
Peer Reviewed
See detailElectrokinetic Model Refinement Via a Perturbation Finite-Element Method—From 2-D to 3-D
Ferreira da Luz, Mauricio V.; Dular, Patrick ULg; V Sabariego, Ruth ULg et al

in IEEE Transactions on Magnetics (2010), 46(8), 2839-2842

A method for increasing the contact area of a grounding system with the earth is the installation of counterpoise wires. Counterpoise wires improve the reliability of overhead power transmission lines ... [more ▼]

A method for increasing the contact area of a grounding system with the earth is the installation of counterpoise wires. Counterpoise wires improve the reliability of overhead power transmission lines. They are conductors buried in the ground parallel to or at an angle to the line conductors. This paper presents an electrokinetic model refinement via a perturbation finite-element method to calculate the grounding resistance of counterpoise wires. The perturbation method is herein developed for refining the electric field distribution in soil starting from simplified models, based on electric field distributions from 2-D models, that evolve towards a 3-D accurate model. The analysis of the distribution of the electric field and of the electric potential around the tower footing allows accurately determining the tower footing resistance. The comparisons between the grounding resistance simulated and calculated analytically of a counterpoise wire are presented. [less ▲]

Detailed reference viewed: 73 (1 ULg)
Peer Reviewed
See detailELECTROKINETICAL ASPECTS DURING BETA-GALACTOSIDASE IMMOBILIZATION ONTO SOLID SUPPORT
Paquot, Michel ULg; HASNAOUI, A.

in Lebensmittel-Wissenschaft & -Technologie = Food Science & Technology (1986), 19(1), 17-21

Detailed reference viewed: 4 (0 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic absorption properties of carbon nanotube nanocomposite foam filling honeycomb waveguide structures
Quiévy, Nicolas; Bollen, Pierre; Thomassin, Jean-Michel ULg et al

in IEEE Transactions on Electromagnetic Compatibility (2012), 24(1), 43-51

Carbon nanotube reinforced polymer foams filling a metallic honeycomb were processed and characterized for the production of hybrid materials with high electromagnetic absorption potential ... [more ▼]

Carbon nanotube reinforced polymer foams filling a metallic honeycomb were processed and characterized for the production of hybrid materials with high electromagnetic absorption potential. Electromagnetic modeling and experimental characterization of the hybrids proved that the honeycomb, acting as a hexagonal waveguide, improves the absorption properties in the gigahertz range above the cutoff frequency. The electromagnetic absorption can be tuned by changing the hybrid material properties. The required levels of electrical conductivity are attained owing to the dispersion of low amounts (1–2 wt%) of carbon nanotubes inside the polymermatrix. The combination of the foam and honeycomb architecture contributes to decrease the real part of the relative effective permittivity Re{εr,eff }. Varying the cell shape of the honeycomb changes the frequency range for high absorption. An analytical model for the absorption has been developed, showing good agreement with the experimental results. [less ▲]

Detailed reference viewed: 29 (3 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic compatibility analysis of unstructured mains networks for high-speed data transmission: Part 1
Battermann, Sven; Garbe, Heyno; Silva, Ferran et al

in IET Science, Measurement & Technology (2008), 2(3), 146-153

Different approaches for the characterisation of relevant parameters of the low-voltage mains network, used for high-speed data transmission (BPL, broadband over power line) are described. Part 1 of the ... [more ▼]

Different approaches for the characterisation of relevant parameters of the low-voltage mains network, used for high-speed data transmission (BPL, broadband over power line) are described. Part 1 of the paper depicts the disturbance scenario of these BPL devices and the motivation will be given for the development of a new measurement procedure in CISPR for the estimation of the high-frequency characteristics of AC mains network. The improvements of the measurement method is not restricted to BPL applications, but can also be applied to other wire-based telecommunication systems. Part 2 of the paper shows the definitions and comparisons of different symmetry factors. The transfer of the results on the compliance test for BPL devices will be shown. [less ▲]

Detailed reference viewed: 48 (0 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic compatibility analysis of unstructured mains networks for high-speed data transmission: Part 2
Battermann, Sven; Garbe, Heyno; Silva, Ferran et al

in IET Science, Measurement & Technology (2008), 2(3), 154-159

Different approaches are described for the characterisation of the low voltage mains network that is used for high-speed data transmission broadband over power line (BPL). Part 1 investigated the ... [more ▼]

Different approaches are described for the characterisation of the low voltage mains network that is used for high-speed data transmission broadband over power line (BPL). Part 1 investigated the disturbance scenario of these BPL devices and importance will be given to develop a new measurement procedure in Comite Internationale Special des Perturbations Radioelectrotechnique (CISPR) to estimate the high-frequency characteristics of AC mains networks. The improvements of the measurement method that can also be applied to other wire-based telecommunication systems will also be presented. Part 2 shows the definitions and comparisons of different symmetry factors. The transfer of the results on the compliance test for BPL devices will also be depicted. [less ▲]

Detailed reference viewed: 56 (0 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic force density in a ferromagnetic material
Henrotte, François; Vande Sande, Hans; Deliège, Geoffrey ULg et al

in IEEE Transactions on Magnetics (2004), 40(2), 553-556

Detailed reference viewed: 9 (0 ULg)
See detailElectromagnetic force density in a ferromagnetic material
Henrotte, François; Vande Sande, Hans; Deliège, Geoffrey ULg et al

Conference (2003)

Detailed reference viewed: 28 (1 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic hypersensitivity and occupational exposure to electromagnetic fields (EMF)
Demaret, Isabelle ULg

Conference (2014, April 07)

Introduction Scientific publications on electromagnetic hypersensitivity began in the early 80' and were first related to video display terminals in the professional environment. Electromagnetic ... [more ▼]

Introduction Scientific publications on electromagnetic hypersensitivity began in the early 80' and were first related to video display terminals in the professional environment. Electromagnetic hypersensitivity is now more heterogeneous and complaints about electromagnetic fields (EMF) are often associated to mobile phone or wifi. Provocation studies did not find that persons claiming to have electromagnetic hypersensitivity were more able to detect EMF than others or that they displayed any special physiological changes when exposed to EMF. Since 1996, WHO defined this syndrome as Idiopathic Environmental Intolerance to ElectroMagnetic Fields (IEI-EMF), characterised by symptoms attributed to EMF. The diagnostic is made by the person itself. The symptoms are heterogeneous and are frequently encountered in the general population. Despite the lack of a proven causal relationship with EMF, these symptoms, and the anxiety related, can lead to important suffering. Some persons with IEI-EMF are even unable to work. IEI-EMF is classified among the functional somatic syndromes as other syndromes with no physiological basis (as multiple chemical sensitivity). Directive and IEI-EMF Studies showed that persons who feel more stressed in their professional environment and are less satisfied with their work are more prone to IEI-EMF. There are some elements in the directive that could frighten these persons: the directive does not consider long term effects; the limit values can be exceeded temporarily and a worker must be informed that he can have transient symptoms. Discussion Persons with IEI-EMF are afraid of adverse health effects and often think that these effects are not taken into account by official agency. For them, everything that can aggravate their fears will be difficult to handle. [less ▲]

Detailed reference viewed: 22 (2 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic modes in dusty plasmas with charge and mass distributions
Verheest, F.; Cattaert, Tom ULg

in Physics of Plasmas (2003), 10(4), 956-962

Electromagnetic modes in dusty plasmas are studied for polydisperse dust grains with a distribution in charge and mass. Owing to the different charge and mass weightings of the velocities, there occurs an ... [more ▼]

Electromagnetic modes in dusty plasmas are studied for polydisperse dust grains with a distribution in charge and mass. Owing to the different charge and mass weightings of the velocities, there occurs an infinite chain of equations of motion, coupled through the magnetic part of the Lorentz force. Depending on the frequency and associated convergence regimes, one has to close the chain in ascending or in descending order. Both series together lead to the polydisperse dispersion law that is a generalization of monodisperse or size distributed dust. Power-law distributions typical for heliospheric plasmas are discussed as an application. (C) 2003 American Institute of Physics. [less ▲]

Detailed reference viewed: 8 (1 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic properties for arbitrary spin particles: Natural electromagnetic moments from light-cone arguments
Lorce, Cédric ULg

in Physical Review. D, Particles, Fields, Gravitation, and Cosmology (2009), D79

We revisit the old-standing problem of the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and $Q^2=0$ should be conserved ... [more ▼]

We revisit the old-standing problem of the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and $Q^2=0$ should be conserved nontrivially by the electromagnetic interaction, we are able to derive all the natural electromagnetic moments for a pointlike particle of any spin. We provide here a transparent decomposition of the electromagnetic current in terms of covariant vertex functions. We also define in a general way the electromagnetic multipole form factors, and show their relation with the electromagnetic moments and covariant vertex functions. The light-cone helicity conservation argument determines uniquely the values of all electromagnetic moments, which we refer to as the ‘‘natural’’ ones. These specific values are in accordance with the standard model, and the prediction of universal g=2 gyromagnetic factor is naturally recovered. We provide a very simple and compact formula for these natural moments. As an application of our results, we generalize the discussion of quark transverse charge densities to particles with arbitrary spin, giving more physical support to the light-cone helicity conservation argument. [less ▲]

Detailed reference viewed: 10 (2 ULg)
Peer Reviewed
See detailElectromagnetic waves in periodic structures
Guenneau, S.; Nicolet, A.; Geuzaine, Christophe ULg et al

in Proceedings of the Eleventh International Symposium on Applied Electromagnetics and Mechanics, ISEM 2003 (2003)

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailElectromechanical FEM models and electrostatic forces near sharp corners
Hannot, Stephan; Rixen, Daniel; Andreykiv, Andriy et al

E-print/Working paper (2009)

Accounting for multiphysical coupling in models of Micro Electro Mechanical Systems (MEMS) is essential for accurate simulations. One essential multiphysical effect in MEMS is the electromechanical ... [more ▼]

Accounting for multiphysical coupling in models of Micro Electro Mechanical Systems (MEMS) is essential for accurate simulations. One essential multiphysical effect in MEMS is the electromechanical coupling since electrostatic forces are often used for actuation or sensing in those devices. Often MEMS are designed such that their shape exhibits many corners. In this paper two different numerical approaches are used to model this coupling using the Finite Element Method: the electrostatic forces are either derived from the variational approach or a local approach based on the Maxwell stress tensor such as implemented in commercial Finite Element codes. The evaluation of electrostatic forces near corners is investigated in detail and in this paper the two approaches are compared around corners. Although the issue of numerical models around singularities is not new, the question addressed here is related to the computation of electric forces in the vicinity of corners. Since those forces are quadratic functions of the electric field, namely the gradient of the electric potential, here the primal unknown, computing those forces accurately is a challenge in itself. Elements which use special shape functions are used to discretize the field near this corner singularity as well. In the work presented here, it is shown that a significant discrepancy appears in the electrostatic force computed around a corner depending on the discretization approach considered, and we conclude that the variational approach or equivalently the full Maxwell tensor should be used to properly evaluate electrostatic forces around corners. [less ▲]

Detailed reference viewed: 84 (6 ULg)
Full Text
Peer Reviewed
See detailElectrometric assessment of the effect of a zinc oxide paste in diaper dermatitis.
Xhauflaire, Emmanuelle ULg; Henry, Frédérique ULg; Pierard, Claudine ULg et al

in International Journal of Cosmetic Science (2009), 31(5), 369-74

Diaper dermatitis affects nearly 50% of infants as well as some bed-ridden adults particularly in the elderly people. This condition is induced by irritation and maceration, and may be further exacerbated ... [more ▼]

Diaper dermatitis affects nearly 50% of infants as well as some bed-ridden adults particularly in the elderly people. This condition is induced by irritation and maceration, and may be further exacerbated by Candida sp. colonization and infection. A key factor in the pathogenesis is the alteration in both the barrier function and the water-holding capacity of the stratum corneum. The purpose of this study was to assess the effects of an unmedicated zinc oxide-petrolatum paste and to observe for possible shielding and restoring effects on the water-holding capacity of the stratum corneum altered by diaper dermatitis. The paste appeared to load the hollow skin microrelief. It was inferred that this effect was responsible for a reticulated shielding effect. Compared with healthy skin and untreated diaper dermatitis, the application of the anhydrous paste resulted in a trend to normalize electrometric properties of skin reflecting the combination of transepidermal water loss and the water-holding capacity of the stratum corneum. [less ▲]

Detailed reference viewed: 35 (0 ULg)
Full Text
Peer Reviewed
See detailElectromyographic activity of the knee flexors and extensors during isokinetic fatigue assessments
Maquet, Didier ULg; Bosquet, L.; Forthomme, Bénédicte ULg et al

in Isokinetics & Exercise Science (2007), 15

Detailed reference viewed: 23 (4 ULg)