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See detailMeasurement of the magnetic field inside the holes of a drilled bulk high-Tc superconductor
Lousberg, Grégory ULg; Fagnard, Jean-François ULg; Noudem, Jacques G et al

in Superconductor Science and Technology (2009), 22

We use macroscopic holes drilled in a bulk YBCO superconductor to probe its magnetic properties in the volume of the sample. The sample is subjected to an AC magnetic flux with a density ranging from 30 ... [more ▼]

We use macroscopic holes drilled in a bulk YBCO superconductor to probe its magnetic properties in the volume of the sample. The sample is subjected to an AC magnetic flux with a density ranging from 30 to 130 mT and the flux in the superconductor is probed by miniature coils inserted in the holes. In a given hole, three different penetration regimes can be observed: (i) the shielded regime, where no magnetic flux threads the hole; (ii) the gradual penetration regime, where the waveform of the magnetic field has a clipped sine shape whose fundamental component scales with the applied field; and (iii) the flux concentration regime, where the waveform of the magnetic field is nearly a sine wave, with an amplitude exceeding that of the applied field by up to a factor of two. The distribution of the penetration regimes in the holes is compared with that of the magnetic flux density at the top and bottom surfaces of the sample, and is interpreted with the help of optical polarized light micrographs of these surfaces. We show that the measurement of the magnetic field inside the holes can be used as a local characterization of the bulk magnetic properties of the sample. [less ▲]

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See detailMeasurement of the magnetic flux threading holes of drilled superconductors
Lousberg, Grégory ULg

Poster (2007, September)

Article associé : Measurement of the magnetic field inside the holes of a drilled bulk high-Tc superconductor

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See detailMeasurement of the magnetic hysteresis cycle of bulk superconductor / ferromagnet hybrids
Philippe, Matthieu ULg; Fagnard, Jean-François ULg; Wera, Laurent ULg et al

Conference (2013, November 07)

Large grain, bulk YBa2Cu3O7-δ (YBCO) high temperature superconductors (HTS) can be potentially used as powerful permanent magnets for magnetic levitation. The magnetic flux distribution above a bulk HTS ... [more ▼]

Large grain, bulk YBa2Cu3O7-δ (YBCO) high temperature superconductors (HTS) can be potentially used as powerful permanent magnets for magnetic levitation. The magnetic flux distribution above a bulk HTS magnet, however, is strongly non-uniform compared to the rather flat distribution above a ferromagnet. In the present work, we study experimentally how cylindrical pieces of FeNi soft ferromagnetic alloys can be combined with a cylindrical, bulk, large grain YBCO superconductor to improve the distribution of the trapped field at the surface or its average value through the volume of the sample. The magnetic properties of each hybrid structure are measured at 77 K under axial magnetic field up to 3 T. The remanent induction distribution near the top and bottom surfaces is determined by miniature Hall probe mapping. Pick-up coils wound around the superconductor are used to measure the average flux density inside the superconductor. This technique relies on low level voltage measurements (typically a few microvolts) and allows non-destructive measurement of the average magnetic hysteresis curve of the entire bulk superconductor. [less ▲]

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See detailMeasurement of the partial pressure of CO2 in bulk sea ice
Geilfus, Nicolas-Xavier ULg; Verbeke, Véronique; Delille, Bruno ULg et al

Poster (2007, July)

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Peer Reviewed
See detailMeasurement of the power output during the acceleration phase of all-put arm cranking exercise
Vanderthommen, Marc ULg; Francaux, Marc; Johnson, D. et al

in International Journal of Sports Medicine (1997), 18

Detailed reference viewed: 9 (0 ULg)
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See detailMeasurement of the tibial subchondral bone mineral density: a potential tool for diagnosis and monitoring of knee osteoarthrits
Bruyère, Olivier ULg; Zegels, Brigitte ULg; Dardenne, Charles-Bernard et al

in Osteoarthritis and Cartilage (2001), 9(Suppl.B), 61

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See detailMeasurement of the tibial subchondral bone mineral density: a potential tool for diagnosis and monitoring of knee osteoarthrits
Bruyère, Olivier ULg; Zegels, Brigitte ULg; Dardenne, Charles-Bernard et al

in Clinical Rheumatology (2001), 5(Suppl.1), 411

Detailed reference viewed: 4 (0 ULg)
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See detailMeasurement of tomato firmness by using a non-destructive mechanical sensor
Lesage, Patrick; Destain, Marie-France ULg

in Postharvest Biology & Technology (1996), 8

A non-destructive mechanical sensor (Cantifruit) was designed to measure the firmness of tomatoes. It consists of a small plunger constrained to penetrate slightly into the fruits, by using an accurate ... [more ▼]

A non-destructive mechanical sensor (Cantifruit) was designed to measure the firmness of tomatoes. It consists of a small plunger constrained to penetrate slightly into the fruits, by using an accurate lever mechanism. A highly significant correlation exists between firmness measurements performed with this device and the Stable Micro Systems (SMS), fitted with the same plunger dimaeter. Using the Cantifruit, data related to firmness variability and changes are easily obtained. The firmness of tomatoes varies about 12 % around its circumference. In a single lot of tomatoes picked at the same time, the variability may exceed 25 %. If the tomatoes are stored at 4-5 °C and 92-99 % relative humidity (RH), their firmness decreases by about 20 % over ten days. [less ▲]

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See detailMeasurement of Total Respiratory Impedance in Calves by the Forced Oscillation Technique
Gustin, Pascal ULg; Dhem, A.R.; Lomba, Fernand et al

in Journal of Applied Physiology (Bethesda, Md. : 1985) (1988), 64(5), 1786-1791

We have determined the resistance (Rrs) and the reactance (Xrs) of the total respiratory system in unsedated spontaneously breathing calves at various frequencies. A pseudorandom noise pressure wave was ... [more ▼]

We have determined the resistance (Rrs) and the reactance (Xrs) of the total respiratory system in unsedated spontaneously breathing calves at various frequencies. A pseudorandom noise pressure wave was produced at the nostrils of the animals by means of a loudspeaker adapted to the nose by a tightly fitting mask. A Fourier analysis of the pressure in the nostrils and flow signals yielded mean Rrs and Xrs, over 16 s, at frequencies of 2-26 Hz. A good correlation was found between values of pulmonary resistances measured by the isovolume method at the respiratory frequency of animals and values obtained at a frequency of 6 Hz by use of our technique. The linearity of the respiratory system, the reproducibility of the technique, and the effects of upper airways on results have been studied. In healthy calves, Rrs increases with frequency. Mean resonant frequency is 7.5 Hz. Bronchospasm was induced in six calves by administration of intravenous organophosphates. Rrs tended to decrease with increasing frequency. Resonant frequency exceeded 26 Hz. All parameters returned to initial values after administration of atropine. In healthy calves, atropine produces a decrease in Rrs, especially at low frequencies. Values of resonant frequency are not modified. [less ▲]

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See detailMeasurement of Total Respiratory Impedance in Dogs by the Forced Oscillation Technique
Clercx, Cécile ULg; Gustin, Pascal ULg; Landser, F. J. et al

in Veterinary Research Communications (1993), 17(3), 227-239

The resistance (Rrs) and reactance (Xrs) of the total respiratory system were determined at various frequencies in 14 healthy conscious beagle dogs. A pseudorandom noise pressure wave was produced at the ... [more ▼]

The resistance (Rrs) and reactance (Xrs) of the total respiratory system were determined at various frequencies in 14 healthy conscious beagle dogs. A pseudorandom noise pressure wave was produced at the nostrils of the animals by means of a loudspeaker adapted to the nose by a tightly fitting mask. A Fourier analysis of the pressure and flow signals yielded mean Rrs and Xrs, over 16 s, at frequencies from 2 to 26 Hz. The influence of the posture of the dog, the position of its head, the linearity of the respiratory system, the reproducibility of the method and the effects of upper and lower airway obstructions were studied. In sitting and standing healthy dogs with the head in the extended position, Rrs values increased progressively with frequency from 5.4 +/- 0.4 (SEM) cmH2O L-1s at 6 Hz up to 8.8 +/- 0.7 cmH2O L-1s at 26 Hz, the mean resonant frequency being 6.1 +/- 0.5 Hz. No significant differences were observed between measurements performed with the head in the normal or the extended position. In a recumbent posture, all Rrs values were increased but Rrs was still dependent on the frequency in the same way (7.1 +/- 0.7 cmH2O L-1s at 6Hz up to 10.0 +/- 0.5 cmH2O L-1s at 26 Hz). Tracheal compression also induced higher Rrs values without changes in the frequency dependence or in the resonant frequency. In anaesthetized dogs, airway obstruction was induced by inhalation of histamine (4 mg/ml for 5 min; the Rrs values tended to decrease with increasing frequency, and the resonant frequency was markedly increased [less ▲]

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See detailMeasurement of Trace levle Dechlorane Flame Retardants in Food and Feed by GC-MS/MS
L'Homme, Benjamin ULg; Calaprice, C; Brasseur, Catherine ULg et al

Poster (2014, May 21)

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See detailMeasurement of urinary biomarkers of parabens, benzophenone-3 and phthalates in a Belgian population
Dewalque, Lucas ULg; PIRARD, Catherine ULg; Charlier, Corinne ULg

in BioMed Research International (2014), 2014(Article ID 649314,), 1-13

Parabens, benzophenone-3 (BP3) and phthalates are commonly used as antimicrobial conservator, UV-filter and plasticizer respectively, and are thought to exhibit endocrine disrupting properties. These ... [more ▼]

Parabens, benzophenone-3 (BP3) and phthalates are commonly used as antimicrobial conservator, UV-filter and plasticizer respectively, and are thought to exhibit endocrine disrupting properties. These endocrine disrupting activities have been recently assumed to lead to cutaneous malignant melanoma. Humans are exposed to these chemicals through different sources such as food, personal care products or cosmetics. In this study we measured urinary levels of 4 parabens, BP3 and 7 metabolites of phthalates in samples collected from 261 participants living in and around Liege (Belgium). The analyses were carried out by liquid chromatography tandem mass spectrometry (LC-MS/MS) using isotopic dilution. To the best of our knowledge, this is the first time that the urinary levels of these 3 classes of chemicals are reported for the same general population in Belgium. Most of the parabens, the BP3 and all the phthalate metabolites were detected in 82.8 to 100.0% of the samples. For most of these chemicals, the exposure patterns significantly differ between children and adults, but also between males and females, especially with higher concentrations of parabens and phthalate metabolites in female and children subjects respectively. [less ▲]

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See detailMeasurement requirements for environmental monitoring : application of the electronic nose principle.
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Andre, Philippe ULg

Conference (2000)

As regards environment, the information to be provided to the decision maker or to the manager must be clear, accurate, unambiguous, and ideally it should be the result of the aggregation of a great ... [more ▼]

As regards environment, the information to be provided to the decision maker or to the manager must be clear, accurate, unambiguous, and ideally it should be the result of the aggregation of a great number of data or parameters. For example, the person in charge of the security of a municipality must have at his disposal an information of the type "all or nothing" to be able to decide if the population must be evacuated in the event of a severe pollution. However, that very simple information should be the result of a calculation based on several time series of pollutant concentration values and of meteorological data. Even the farmer who wants to know if it is the right time to spread manure without affecting too much the environment must have a single information which should be the aggregation of some complex variables. The lecture presents the concept of some "integrated index", already used to assess the quality of the environment. For example, Organic Pollution Index combines 4 laboratory measurement values of pollutants in water to make a single index characterising the global pollution in a river. Some apparatus are able to compute the integrated index "on line" and to supply directly to the user the value of the medium quality. For example, the PMV index estimates globally the thermal comfort in a building from the on line measurement of 5 parameters. FUL has designed some "smart sensors" or "smart instrument" aiming at supplying such index. Two applications are presented. The first one concerns the measurement of soil quality by means of a porous sensor combining in a single index the measurement of temperature, salinity and water contents. But the lecture develops particularly a second application which exploits the principle of the "electronic nose" to assess, in a single "signature", the quality or the intensity of an environmental odour. Such instrument, equipped with an array of "non specific" gas sensors, should be able, after a suitable learning phase, to recognise the odour source and to monitor it continuously in the field. The instrument response is thus a "pattern", similar to an integrated index, directly related to the annoyance, as felt by neighbouring people. It gives thus an information which can be handled by a manager, and which is more rich than individual pollutant concentration values. FUL has tested such instrument in the environment. The results are promising : a first design of electronic nose was able to recognise 5 odorous sources in the environment, and a portable instrument has been used to monitor the odour around a landfill site. The same concept is now tested to appraise as a whole the indoor air quality in different buildings. [less ▲]

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See detailMeasurement uncertainty for persistent organic pollutants by isotope dilution mass spectrometry
Eppe, Gauthier ULg; Diletti, G; Fernandes, A et al

in Organohalogen Compounds (2014, September), 76

Detailed reference viewed: 7 (4 ULg)
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See detailMeasurement uncertainty for the analysis of serum 25-hydroxyvitamin D: response to Stepman and Thienpont
Cavalier, Etienne ULg; Delanaye, Pierre ULg; Cormier, Catherine et al

in Osteoporosis International (2010), 21

Detailed reference viewed: 41 (2 ULg)