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See detailMeasurements of Column Abundances of Nitrogen Dioxide, NO2, from the Ground During the Globus-NOx Campaign
Zander, Rodolphe ULg; Demoulin, Philippe ULg; Roland, Ginette et al

in Bojkov, Rumen D.; Fabian, Peter (Eds.) Ozone in the Atmosphere, Proceedings of the Quadrennial Ozone Symposium 1988 and Tropospheric Ozone Workshop (1989)

Detailed reference viewed: 14 (2 ULg)
See detailMeasurements of EMG activity of pericranial muscles in tension-type headache
MAERTENS DE NOORDHOUT, Alain ULg; Schoenen, Jean ULg

in Olesen, J.; Schoenen, Jean (Eds.) Tension-Type Headache: classification, mechanisms and treatment (Frontiers in Headache Research) (1993)

Detailed reference viewed: 19 (3 ULg)
See detailMeasurements of HCFC-22 and validation update
Kolonjari, F.; Walker, K.A.; Mahieu, Emmanuel ULg et al

Scientific conference (2012, May 24)

This talk reports about global HCFC-22 measurements derived from ACE-FTS occultation observations recorded from 2004 onwards. It further provides information on the validation of ACE-FTS products for CFC ... [more ▼]

This talk reports about global HCFC-22 measurements derived from ACE-FTS occultation observations recorded from 2004 onwards. It further provides information on the validation of ACE-FTS products for CFC-11, -12 and HCFC-22 with ground-based FTIR instruments operated at four sites: Eureka, Poker Flat, Toronto and Jungfraujoch. [less ▲]

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See detailMeasurements of heat, water vapour and CO2 fluxes above a mixed forest
Aubinet, Marc ULg; Longdoz, Bernard ULg; Yernaux, Michel et al

in Shimizu, H. (Ed.) Carbon dioxide and vegetation : Advanced approaches for absorption of CO2 and responses to CO2 (2001)

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See detailMeasurements of hindlimb blood flow recorded using Doppler ultrasound during administration of vasoactive agents in halothane-anesthetized horses
Raisis, Anthea L; Young, Lesley E; Meire, Hylton B et al

in Veterinary Radiology & Ultrasound : The Official Journal of the American College of Veterinary Radiology & the International Veterinary Radiology Association (2000), 41(1), 64-72

The purpose of the study was to determine the ability of Doppler ultrasound to detect changes in femoral blood flow during pharmacologic manipulation of arterial blood pressure. Doppler ultrasonography ... [more ▼]

The purpose of the study was to determine the ability of Doppler ultrasound to detect changes in femoral blood flow during pharmacologic manipulation of arterial blood pressure. Doppler ultrasonography was performed in the femoral vessels of six halothane-anesthetized horses before and during administration of phenylephrine HCI and sodium nitroprusside. The time-averaged mean velocity and volumetric flow were calculated. The contour of the velocity waveform was assessed, and the early diastolic deceleration slope (EDDS) and pulsatility index (PI) were calculated. Administration of phenylephrine HCI resulted in increased mean aortic blood pressure (MABP) by 40% (29.3-53.0%). This caused significant decrease in cardiac output (26.8 to 13.5 l/min), femoral arterial velocity (left artery 7.20 to 4.00 cm/s; right artery 5.01 to 3.39 cm/s) and volumetric flow (left artery 556 to 221 ml/min; right artery 397 to 193 ml/min) in the femoral vessels and significant increase in systemic vascular resistance (163 to 433 dyn-s/cm5), EDDS (1a: 285 to 468: ra: 250 to 481) and PI (1a: 9.38 to 20.4; ra 17.1 to 29.1). Administration of sodium nitroprusside resulted in a decreased MABP of 27.2% (22.5-33%). This increased cardiac output (20.8 to 32.4 L/min), however, no significant changes were observed in femoral blood flow. Despite obvious changes in the waveform contour, no significant change occurred in EDDS or PI. These results suggest that Doppler ultrasound may be useful for measuring femoral blood flow in anesthetized horses. However, waveform analysis appears to be limited when multiple changes occur in central and peripheral haemodynamics. [less ▲]

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See detailMeasurements of hydrogen cyanide (HCN) and acetylene (C2H2) from the Infrared Atmospheric Sounding Interferometer (IASI)
Duflot, V.; Hurtmans, D.; Clarisse, L. et al

in Atmospheric Measurement Techniques (2013), 6

Hydrogen cyanide (HCN) and acetylene (C2H2) are ubiquitous atmospheric trace gases with medium lifetime, which are frequently used as indicators of combustion sources and as tracers for atmospheric ... [more ▼]

Hydrogen cyanide (HCN) and acetylene (C2H2) are ubiquitous atmospheric trace gases with medium lifetime, which are frequently used as indicators of combustion sources and as tracers for atmospheric transport and chemistry. Because of their weak infrared absorption, overlapped by the CO2 Q branch near 720 cm−1, nadir sounders have up to now failed to measure these gases routinely. Taking into account CO2 line mixing, we provide for the first time extensive measurements of HCN and C2H2 total columns at Reunion Island (21° S, 55° E) and Jungfraujoch (46° N, 8° E) in 2009–2010 using observations from the Infrared Atmospheric Sounding Interferometer (IASI). A first order comparison with local ground-based Fourier transform InfraRed (FTIR) measurements has been carried out allowing tests of seasonal consistency which is reasonably captured, except for HCN at Jungfraujoch. The IASI data shows a greater tendency to high C2H2 values. We also examine a nonspecific biomass burning plume over austral Africa and show that the emission ratios with respect to CO agree with previously reported values. [less ▲]

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See detailMeasurements of long-term changes in atmospheric OCS (carbonyl sulfide) from infrared solar observations
Rinsland, Curtis P.; Chiou, Linda S.; Mahieu, Emmanuel ULg et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2008), 109(16), 2679-2686

Multi-decade atmospheric OCS (carbonyl sulfide) infrared measurements have been analyzed with the goal of quantifying long-term changes and evaluating the consistency of the infrared atmospheric OCS ... [more ▼]

Multi-decade atmospheric OCS (carbonyl sulfide) infrared measurements have been analyzed with the goal of quantifying long-term changes and evaluating the consistency of the infrared atmospheric OCS remote-sensing measurement record. Solar-viewing grating spectrometer measurements recorded in April 1951 at the Jungfraujoch station (46.5°N latitude, 8.0°E longitude, 3.58 km altitude) show evidence for absorption by lines of the strong ν3 band of OCS at 2062 cm(−1). The observation predates the earliest previously reported OCS atmosphere remote-sensing measurement by two decades. More recent infrared ground-based measurements of OCS have been obtained primarily with high-resolution solar-viewing Fourier transform spectrometers (FTSs). Long-term trends derived from this record span more than two decades and show OCS columns that have remained constant or have decreased slightly with time since the Mt. Pinatubo eruption, though retrievals assuming different versions of public spectroscopic databases have been impacted by OCS ν3 band line intensity differences of 10%. The lower stratospheric OCS trend has been inferred assuming spectroscopic parameters from the high-resolution transmission (HITRAN) 2004 database. Volume mixing ratio (VMR) profiles measured near 30°N latitude with high-resolution solar-viewing FTSs operating in the solar occultation mode over a 22 years time span were combined. Atmospheric Trace MOlecucle Spectroscopy (ATMOS) version 3 FTS measurements in 1985 and 1994 were used with Atmospheric Chemistry Experiment (ACE) measurements during 2004–2007. Trends were calculated by referencing the measured OCS VMRs to those of the long-lived constituent N2O to account for variations in the dynamic history of the sampled airmasses. Means and 1-sigma standard deviations of VMRs (in ppbv, or 10−9 per unit air volume) averaged over 30–100 hPa from measurements at 25–35°N latitude are 0.334±0.089 ppbv from 1985 (ATMOS Spacelab 3 measurements), 0.297±0.094 ppbv from 1994 ATLAS 3 measurements, 0.326±0.074 ppbv from ACE 2004 measurements, 0.305±0.096 ppbv from ACE 2005 measurements, 0.328±0.074 from ACE 2006 measurements, and 0.305±0.090 ppbv from ACE measurements through August 2007. Assuming these parameters, we conclude that there has been no statistically significant trend in lower stratospheric OCS over the measurement time span. We discuss past measurement sets, quantify the impact of changes in infrared spectroscopic parameters on atmospheric retrievals and trend measurements, and discuss OCS spectroscopic uncertainties of the current ν3 band parameters in public atmospheric databases. [less ▲]

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See detailMeasurements of mediator cascades during adult respiratory distress syndrome
Lamy, Maurice ULg; Deby-Dupont, G.; Deby, C. et al

in Adult Respiratory Distress Syndrome (1992)

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See detailMeasurements of microbial N flow to the duodenum and urinary excretion of purine derivatives in bulls.
Beckers, Yves ULg; Thewis, André ULg; Sohy, Christophe et al

in Annales de Zootechnie (1995), 44

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See detailMeasurements of non-Rutherford cross sections for 4-15 MeV alpha particles on light elements from C to Si
Chene, Grégoire ULg; Mathis, François ULg; Fleury-Frenette, Karl ULg et al

Conference (2013, September)

These last years Ion Beam Analysis users show an interest in High Energy Alpha beams[1]. These beams can be used for on-site analysis by means of radioactive sources e.g. for space application but they ... [more ▼]

These last years Ion Beam Analysis users show an interest in High Energy Alpha beams[1]. These beams can be used for on-site analysis by means of radioactive sources e.g. for space application but they also offer a powerful combination of properties for the analysis of thick layers (about 10 to 20 µm). This kind of layers is often met in cultural heritage applications but can be also present on new materials. Contrary to this kind of materials where the principal information needed is the in-depth profiles as the sample are of known composition, for cultural heritage materials the combination of elemental analysis and their in-depth distribution is essential as the nature of the material is a-priori not known. In this perspective high energy alpha beams can produce really interesting results as their PIXE cross-sections increase from 6 MeV while the lower penetration of the beam (comparing to classical protons beams) allows to limit the analysis to the layer of interest. For the elemental in depth distribution we take advantage of the good mass separation of the alpha particles and the non-Rutherford phenomena allow the analysis even of light elements which are of great interest in cultural heritage problematic as far as the cross section are well tabulated. Using two IBA facilities (AGLAE in Paris and the HE-HR beam line of the cyclotron in Liège University[2]) we explored the backscattering cross section of numerous light elements (from C to Si) from 4 to 15 MeV in order to check the lack in the literature, to verify the deviation from Rutherford law and compare it to the existing theoretical models. We begin to measure the needed cross sections using thick target in case of smooth cross section and thin layers for exploring important variation of the cross section. [less ▲]

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See detailMeasurements of odd nitrogen compounds in the stratosphere by the ATMOS experiment on Spacelab 3
Russell, J. M.; Farmer, C. B.; Rinsland, C. P. et al

in Journal of Geophysical Research. Atmospheres (1988), 93(D2), 1718--1736

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See detailMeasurements of reference ISO nozzles by high-speed imaging
De Cock, Nicolas ULg; Massinon, Mathieu ULg; Nuyttens, David et al

in Crop Protection (2016), 89

Agricultural spray characteristics determine the efficiency of a pesticide application because size and velocity affect droplet trajectory and impact behavior. At present, the relevance of different ... [more ▼]

Agricultural spray characteristics determine the efficiency of a pesticide application because size and velocity affect droplet trajectory and impact behavior. At present, the relevance of different characterization techniques remains controversial since discrepancies may be significant between measurements performed in different laboratories. A digital image acquisition technique and analysis algorithm is proposed for droplet size and velocimetry measurements as an alternative to well-established techniques such as the Phase Doppler Particle Analyzer (PDPA) or laser diffraction spectrometry (LDS). The algorithm requires double exposed shadow images acquired in a back-lighted arrangement with a Particle Image Velocimetry (PIV) camera and a pulsed light emitting diode (LED). Spatial illumination heterogeneities are corrected by subtracting from each image a mean background acquired on several images without any particle. The algorithm accuracy is ensured by the rejection of out-of-focus particles using a focus parameter depending on gradient intensity at the particle edges. Thresholds for focus particle selection were determined by studying the evolution of the focus parameter and the error on particle size measurements from images containing droplets with uniform size at various distance of the object plane. Selected droplets were identified on both pairs of images to determine their size and velocity. Droplet size distributions were corrected to account for the uneven sampling probability caused by the volumetric method. Droplet size distributions of a set of reference nozzle/pressure combinations defined in the ISO/DIS 25358 were measured. The image technique was able to distinguish each of the reference sprays well. Comparison with PDPA measurements showed that the imaging technique tends to measure an equivalent Dv50, a lower Dv10 and a higher Dv90 leading therefore to a higher relative span factor. Velocity measurements showed good agreement between both techniques except for one nozzle/pressure combination. [less ▲]

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See detailMeasurements of the 14N/15N isotopic ratio in comets's ammonia
Rousselot, P.; Pirali, O.; Jehin, Emmanuel ULg et al

Conference (2014, May)

La détermination des rapports isotopiques de l'azote dans les différents objets du système solaire est importante pour une bonne compréhension de leur origine. Les mesures du rapport 14N/15N faites jusqu ... [more ▼]

La détermination des rapports isotopiques de l'azote dans les différents objets du système solaire est importante pour une bonne compréhension de leur origine. Les mesures du rapport 14N/15N faites jusqu'à présent ont montré une grande dispersion des valeurs (de 50 à 441), tous les objets du système solaire excepté Jupiter apparaissant enrichis en 15N comparés à la nébuleuse protosolaire. Différentes explications ont été proposées pour expliquer les valeurs observées, qui sont complexes à interpréter car dues non seulement au réservoir d'origine de l'azote d'où provient l'objet étudié mais également à des mécanismes de fractionnement isotopique. Le cas des comètes, dans ce contexte, est intéressant, car leur composition est supposée relativement proche de celle de la nébuleuse protosolaire et la seule valeur disponible jusqu'à l'année dernière, avait été calculée à partir de la molécule HCN et du radical CN (issu du HCN). Ce rapport était d'environ 150, bien en dessous de la valeur mesurée dans l'atmosphère terrestre (272). Les comètes contiennent beaucoup d'azote sous forme de NH3, photodissocié en NH2 dont les raies sont nombreuses dans le spectre visible. Il était donc possible de mesurer le rapport 14N/15N dans l'ammoniac pour vérifier l'influence possible de phénomènes de fractionnement isotopique entre le HCN et le NH3, ceci à condition de connaître avec précision les longueurs d'onde des raies de 15NH2. Pour déterminer ces longueurs d'onde, nous avons mesuré le spectre d'émission de la transition Ã2A1~X2B1 de 14NH2 et 15NH2 dans la gamme spectrale 5700 Å – 6000 Å sur la ligne AILES du synchrotron SOLEIL, avec un spectromètre par transformée de Fourier. L'analyse de ces spectres a permis, au final, la détection du 15NH2 dans les spectres cométaires et la première détermination du rapport 14N/15N dans l'ammoniac des comètes. [less ▲]

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See detailMeasurements of the ground state ionization energy and wavelengths for the 1snp1P1 - 1s2 1S0(n=4-10) lines of O VII
Bartnik, A.; Biémont, Emile ULg; Dyakin, V. M. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (1997), 30

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See detailMeasurements of the ground state ionization energy and wavelengths for the nl-nl' transitions of Ni XIX (n=4-15) and Ge XXIII (n=7-9)
Biémont, Emile ULg; Magunov, A. I.; Dyakin, V. M. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (2000), 33

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See detailMeasurements of the ground-state ionization energy and wavelengths for the 1snp P-1(1)*-1s(2) S-1(0) (n=4-9) lines of Mg XI and FVIII
Pal'chikov, V. G.; Faenov, A. Y.; Skobelev, I. Y. et al

in Journal of Physics B-Atomic Molecular and Optical Physics (2002), 35(12), 2741-2754

The wavelengths of the 1snp P-1(1)0-1s(2) S-1(0) transitions in the He-like Mg XI (n = 4-9) and F VIII (n = 4-8) have been measured in laser-produced plasmas. The accuracy of the present measurements (0.4 ... [more ▼]

The wavelengths of the 1snp P-1(1)0-1s(2) S-1(0) transitions in the He-like Mg XI (n = 4-9) and F VIII (n = 4-8) have been measured in laser-produced plasmas. The accuracy of the present measurements (0.4-1.6 mAngstrom) is a large improvement over previous results. The Rydberg series is used to determine the ground-state ionization energy of F VIII and Mg XI: E-ion (F VIII) = 953.96 +/- 0.11 eV, E-ion (Mg XI) = 1761.88 +/- 0.15 eV. These experimental results are compared with theoretical data calculated by the 1/Z-expansion method and the HFR and MCDF approaches. Fairly good agreement between theory and experiment is observed with a precision up to 5 x 10(-5). Radiative corrections to the 1s(2) S-1(0) state are analysed and compared with experiments. It is found that QED corrections to the ground-state ionization energy are significant at the present level of experimental accuracy. [less ▲]

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See detailMeasurements of the helium 584 Å airglow during the Cassini flyby of Venus
Gérard, Jean-Claude ULg; Gustin, Jacques ULg; Hubert, Benoît ULg et al

in Planetary and Space Science (2011), 59

The helium resonance line at 584 Å has been observed with the UltraViolet Imaging Spectrograph (UVIS) Extreme Ultraviolet channel during the flyby of Venus by Cassini at a period of high solar activity ... [more ▼]

The helium resonance line at 584 Å has been observed with the UltraViolet Imaging Spectrograph (UVIS) Extreme Ultraviolet channel during the flyby of Venus by Cassini at a period of high solar activity. The brightness was measured along the disk from the morning terminator up to the bright limb near local noon. The mean disk intensity was ˜320 R, reaching ˜700 R at the bright limb. These values are slightly higher than those determined from previous observations. The sensitivity of the 584 Å intensity to the helium abundance is analyzed using recent cross-sections and solar irradiance measurements at 584 Å. The intensity distribution along the UVIS footprint on the disk is best reproduced using the EUVAC solar flux model and the helium density distribution from the VTS3 empirical model. It corresponds to a helium density of 8×10[SUP]6[/SUP] cm[SUP]-3[/SUP] at the level of where the CO[SUB]2[/SUB] is 2×10[SUP]10[/SUP] cm[SUP]-3[/SUP]. [less ▲]

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See detailMeasurements Of The Horizontal Sprayer Boom Movements By Sensor Data Fusion
Ooms, David ULg; Lebeau, Frédéric ULg; Ruter, R. et al

in Computers and Electronics In Agriculture (2002), 33(2),

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See detailMeasurements of thermal effects in a bulk YBCO single domain superconductor submitted to a variable magnetic field
Laurent, Philippe ULg; Vanderbemden, Philippe ULg; Meslin, S. et al

in IEEE Transactions on Applied Superconductivity (2007), 17(2, Part 3), 3036-3039

When YBCO single domains are subjected to a variable magnetic field, the motion of vortices may give rise to a significant temperature increase and a degradation of the superconducting properties. We have ... [more ▼]

When YBCO single domains are subjected to a variable magnetic field, the motion of vortices may give rise to a significant temperature increase and a degradation of the superconducting properties. We have experimentally investigated such effects in bulk melt-processed YBCO single domains. Several temperature sensors, a pick-up coil and two Hall probes were placed against the surface of a monolithic bulk YBCO pellet. Data were simultaneously recorded during the application of ac magnetic fields of various amplitudes, either with or without a pre-existing dc trapped flux. The measurement results agree well with to those obtained by numerical modeling. It was also found that a superimposed dc magnetic moment reduces the temperature increase caused by the ac magnetic field. (C) 2003 IEEE. [less ▲]

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See detailMeasurements of total respiratory impedance in dogs during nasal obstruction by the forced oscillation method
Clercx, Cécile ULg; Gustin, Pascal ULg; Lekeux, Pierre ULg et al

in 7th Comparative Respiratory Society Meeting - Liège - Belgique (1989)

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