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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 ▲]

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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 ▲]

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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 ▲]

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See detailElectromagnetic force density in a ferromagnetic material
Henrotte, François; Vande Sande, Hans; Deliège, Geoffrey ULg et al

Conference (2003)

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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

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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 ▲]

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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 ▲]

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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 ▲]

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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)

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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 ▲]

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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 ▲]

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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

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See detailElectromyographic examination of the human diaphragm using fixed electrodes
Delhez, L.; Fleron, M. H.; Brichant, Jean-François ULg et al

in Archives Internationales de Physiologie et de Biochimie (1987), 95

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See detailElectromyographie et unités de soins intensifs
WANG, François-Charles ULg

Conference (1991, November 22)

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See detailL'électromyographie laryngée
FINCK, Camille ULg

Conference (2010, November)

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See detailElectromyostimulation en medecine du sport
Vanderthommen, Marc ULg; Crielaard, Jean-Michel ULg

in Revue Médicale de Liège (2001), 56(5), 391-5

Neuromuscular electrical stimulation (NMES) is frequently used to strengthen the normal muscle. In medicine, several investigators have highlighted the value of NMES when treating amyotrophy related to ... [more ▼]

Neuromuscular electrical stimulation (NMES) is frequently used to strengthen the normal muscle. In medicine, several investigators have highlighted the value of NMES when treating amyotrophy related to immobilization. The efficacy of NMES of the quadriceps during rehabilitation following anterior cruciate ligament surgery has been well documented. These electrical stimulation programs are composed of stimulation--rest cycles and are performed with the aid of percutaneous electrodes situated in regard to muscle motor points. The stimulation frequency is chosen to induce tetanic contractions and is generally situated between 50 and 100 Hz. During NMES, the trainer or the physiotherapist can accurately modulate a large number of parameters but the sensory discomfort linked to the current intensity remains the major limitation for strength improvement. In the context of rehabilitation, the association of NMES with voluntary exercises is superior to the isolated utilization of the classic program composed of isometric voluntary contractions. To explain this advantage of associating NMES with voluntary contractions, it has been hypothesized that the electrically induced contractions impose specific patterns of muscle recruitment and a particular metabolic solicitation. [less ▲]

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See detailThe electron and proton aurora as seen by IMAGE-FUV and FAST
Frey, H. U.; Mende, S. B.; Carlson, C. W. et al

in Geophysical Research Letters (2001), 28

The Far Ultraviolet Instrument (FUV) on the IMAGE spacecraft observes the aurora in three different channels. One of them (SI12) is sensitive to the signal from precipitating protons, while the other two ... [more ▼]

The Far Ultraviolet Instrument (FUV) on the IMAGE spacecraft observes the aurora in three different channels. One of them (SI12) is sensitive to the signal from precipitating protons, while the other two (WIC and SI13) observe auroral emissions which are not only excited by precipitating electrons, but also by protons. We examine a period when in-situ particle measurements by the FAST spacecraft were available simultaneously with global imaging with FUV. The measured electron and proton energy spectra are used to calculate the auroral brightness along the FAST orbit. The comparison with the FUV/IMAGE observations shows good quantitative agreement and demonstrates that under certain circumstances high proton fluxes may produce significant amounts of auroral FUV emission. [less ▲]

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See detailElectron and Proton Auroral Dynamics
Mende, S. B.; Frey, H. U.; Carlson, C. et al

Conference (2001, May 01)

Data from the IMAGE Wide-band Imaging Camera (WIC),sensitive to far ultraviolet auroras and from the Spectrographic Imager (SI) channel SI12, sensitive to proton precipitation induced Lyman alpha, were ... [more ▼]

Data from the IMAGE Wide-band Imaging Camera (WIC),sensitive to far ultraviolet auroras and from the Spectrographic Imager (SI) channel SI12, sensitive to proton precipitation induced Lyman alpha, were analyzed during a high altitude orbit segment of the IMAGE spacecraft. This segment began during the expansive phase of a substorm. The aurora developed into a double oval configuration, consisting of a set of discrete poleward forms and a separate diffuse auroral oval equatorwards. Although IMF Bz was negative, considerable activity could be seen poleward of the high latitude arcs in the polar cap region. The optical signature of precipitating protons showed that the proton aurora was on the equatorward side of the diffuse aurora and there was a lack of intense energetic proton fluxes in the poleward arcs. A simultaneous FAST pass provided a diagnostic of the particle types in the various regions. These data showed that lower intensity protons were present throughout the entire double oval configuration but with insufficient intensity to produce aurora that could be observed by IMAGE. The FAST data also showed that the bright poleward discrete arcs were accelerated by electrostatic processes, and the wave accelerated electrons were located on the poleward edge of these features. [less ▲]

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