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See detailMeasured Correlations of Auroral Emissions from Jupiter and Saturn With Solar Wind Variations
Clarke, J. T.; Nichols, J.; Gérard, Jean-Claude ULg et al

Conference (2007, December 01)

An extended set of Hubble Space Telescope (HST) observations of the UV auroral emissions from Jupiter and Saturn has been carried out in three campaigns over Jan.-June 2007. This is by far the most ... [more ▼]

An extended set of Hubble Space Telescope (HST) observations of the UV auroral emissions from Jupiter and Saturn has been carried out in three campaigns over Jan.-June 2007. This is by far the most extensive series of remote high resolution imaging of planetary aurora to date, and provides new physical insight into the cause and effect relationships governing the controlling processes for the giant planet auroral emissions. Simultaneous in situ measurements of local solar wind and magnetospheric plasma conditions have been made during two of these campaigns by Cassini at Saturn in Jan. 2007 and by the New Horizons mission approaching Jupiter in Feb. 2007. The UV auroral emission brightness and distributions have also been compared with estimates of the solar wind conditions near each planet extrapolated from near-Earth measurements, which can be verified by comparison with Cassini and New Horizons in situ data. It has been found that there is a good correlation at both planets between total auroral power and solar wind dynamic pressure, at least for the major solar wind disturbances arriving at each planet. At the same time, the nature of the auroral brightenings differs between Jupiter and Saturn, and the source regions of auroral activity are quite different in the two magnetospheres. In this presentation, the HST and solar wind data and the nature of the correlations will be presented. The physical significance of the correlations will be discussed, based on the much denser set of measurements now available. [less ▲]

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See detailMeasurement and comparison of elderly welfare in the EU
Lefebvre, Mathieu ULg

Conference (2010, April)

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See detailMeasurement and laser control of attosecond charge migration in ionized iodoacetylene
Kraus, P. M.; Mignolet, Benoît ULg; Baykusheva, D. et al

in Science (2015), 350(6262), 790-795

The ultrafast motion of electrons and holes after light-matter interaction is fundamental to a broad range of chemical and biophysical processes. We advanced high-harmonic spectroscopy to resolve ... [more ▼]

The ultrafast motion of electrons and holes after light-matter interaction is fundamental to a broad range of chemical and biophysical processes. We advanced high-harmonic spectroscopy to resolve spatially and temporally the migration of an electron hole immediately after ionization of iodoacetylene while simultaneously demonstrating extensive control over the process. A multidimensional approach, based on the measurement and accurate theoretical description of both even and odd harmonic orders, enabled us to reconstruct both quantum amplitudes and phases of the electronic states with a resolution of ~100 attoseconds. We separately reconstructed quasi–field-free and laser-controlled charge migration as a function of the spatial orientation of the molecule and determined the shape of the hole created by ionization. Our technique opens the prospect of laser control over electronic primary processes. [less ▲]

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See detailMeasurement and modeling of ablation of the bottom of supraglacial lakes in western Greenland
Tedesco, Marco; Luthje, M.; Steffen, K. et al

in Geophysical Research Letters (2012), 39(L02502), 5

We report measurements of ablation rates of the bottom of two supraglacial lakes and of temperatures at different depths collected during the summers of 2010 and 2011 in west Greenland. To our knowledge ... [more ▼]

We report measurements of ablation rates of the bottom of two supraglacial lakes and of temperatures at different depths collected during the summers of 2010 and 2011 in west Greenland. To our knowledge, this is the first time that such data sets are reported and discussed in the literature. The measured ablation rates at the bottom of the two lakes are of the order of ∼6 cm/day, versus a rate of ∼2.5–3 cm/day in the case of bare ice of surrounding areas. Though our measurements suggest the presence of a vertical temperature gradient, it is not possible to draw final conclusions as the measured gradient is smaller than the accuracy of our temperature sensors. In-situ measurements are compared with the results of a thermodynamic model forced with the outputs of a regional climate model. In general, the model is able to satisfactorily reproduce the measured quantities with RMSE of the order of 3–4 cm for the ablation and ∼1.5°C in the case of water temperature. Our results confirm that the ablation at the bottom of supraglacial lakes plays an important role on the overall lake volume with the ablation in the case of ice covered by a lake being 110–135% of that over bare ice at nearby locations. Beside ice sheet hydrological implications, melting at the bottom of a supraglacial lake might affect estimates of lake volume from spaceborne visible and near-infrared measurements. [less ▲]

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See detailMeasurement and modeling of methanol deposition/emission in a mixed forest
Laffineur, Quentin ULg; Heinesch, Bernard ULg; Amelynck, Crist et al

in Geophysical Research Abstracts (2011, April 07), 13

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See detailMeasurement and Representation of Ternary Vapour-Liquid-Liquid-Equilibria
Connemann, M; Gaube, J; Karrer, L et al

in Fluid Phase Equilibria (1990), 60((1-2)), 99-118

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See detailMeasurement and simulation of the cross sections for nuclide production in 56Fe and natCr targets irradiated with 0.04- to 2.6-GeV protons
Titarenko, Y. E.; Batyaev, V. F.; Titarenko, A. Y. et al

in Physics of Atomic Nuclei (2011), 74(4), 523-536

The cross sections for nuclide production in thin 56Fe and natCr targets irradiated by 0.04-2.6-GeV protons are measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and ... [more ▼]

The cross sections for nuclide production in thin 56Fe and natCr targets irradiated by 0.04-2.6-GeV protons are measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV for the 60Co 1332-keV γ line. As a result, 649 yields of radioactive residual product nuclei have been obtained. The 27Al(p, x) 22Na reaction has been used as a monitor reaction. The experimental data are compared with the MCNPX (BERTINI, ISABEL), CEM03. 02, INCL4. 2, INCL4. 5, PHITS, and CASCADE07 calculations. © 2011 Pleiades Publishing, Ltd. [less ▲]

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See detailMeasurement and simulation of the cross sections for nuclide production in natW and 181Ta targets irradiated with 0.04- to 2.6-GeV protons
Titarenko, Y. E.; Batyaev, V. F.; Titarenko, A. Y. et al

in Physics of Atomic Nuclei (2011), 74(4), 551-572

The cross sections for nuclide production in thin natWand 181Ta targets irradiated by 0.04-2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 ... [more ▼]

The cross sections for nuclide production in thin natWand 181Ta targets irradiated by 0.04-2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV in the 60Co 1332-keV γ line. As a result, 1895 yields of radioactive residual product nuclei have been obtained. The 27Al(p, x) 22Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03. 02, INCL4. 2, INCL4. 5, PHITS, and CASCADE07 calculations. © 2011 Pleiades Publishing, Ltd. [less ▲]

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See detailMeasurement and simulation of the cross sections for nuclide production in 93Nb and natNi targets irradiated with 0.04- to 2.6-GeV protons
Titarenko, Y. E.; Batyaev, V. F.; Titarenko, A. Y. et al

in Physics of Atomic Nuclei (2011), 74(4), 537-550

The cross sections for nuclide production in thin 93Nb and natNi targets irradiated by 0.04- to 2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions ... [more ▼]

The cross sections for nuclide production in thin 93Nb and natNi targets irradiated by 0.04- to 2.6-GeV protons have been measured by direct γ spectrometry using two γ spectrometers with the resolutions of 1.8 and 1.7 keV in the 60Co 1332-keV γ line. As a result, 1112 yields of radioactive residual nuclei have been obtained. The 27Al(p, x) 22Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations. © 2011 Pleiades Publishing, Ltd. [less ▲]

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See detailMeasurement and simulation of the cross sections for the production of 148Gd in thin natW and 181Ta targets irradiated with 0.4- to 2.6-GeV protons
Titarenko, Y. E.; Batyaev, V. F.; Titarenko, A. Y. et al

in Physics of Atomic Nuclei (2011), 74(4), 573-579

The cross sections for the production of 148Gd in natW and 181Ta targets irradiated by 0.4-, 0.6-, 0.8-, 1.2-, 1.6-, and 2.6-GeV protons at the ITEP accelerator complex have been measured by direct α ... [more ▼]

The cross sections for the production of 148Gd in natW and 181Ta targets irradiated by 0.4-, 0.6-, 0.8-, 1.2-, 1.6-, and 2.6-GeV protons at the ITEP accelerator complex have been measured by direct α spectrometry without chemical separation. The experimental data have been compared with the data obtained at other laboratories and with the theoretical simulations of the yields on the basis of the BERTINI, ISABEL, CEM03. 02, INCL4. 2, INCL4. 5, CASCADE07, and PHITS codes. © 2011 Pleiades Publishing, Ltd. [less ▲]

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See detailMeasurement of 3D Room Impulse Responses with a Spherical Microphone Array
Embrechts, Jean-Jacques ULg

in Proceedings of the Euronoise 2015 Congress (2015, June)

Directional room impulse responses (DRIRs) are composed of the sound contributions reaching a given location in the room from a well-defined direction in space. DRIRs can be useful in many applications ... [more ▼]

Directional room impulse responses (DRIRs) are composed of the sound contributions reaching a given location in the room from a well-defined direction in space. DRIRs can be useful in many applications, such as the evaluation of spatial room acoustics parameters, the detection of unwanted specular reflections or the 3D auralization of acoustic spaces. A spherical array containing 16 microphones has been realized to measure DRIRs. The logarithmic sinesweep technique is first applied to measure 16 impulse responses, one for each microphone. A spherical harmonics (SH) decomposition of the sound field is then obtained. Spatial aliasing, placement errors and the ‘white noise gain’ (WNG) have been analysed to define the useful bandwith of this measure, i.e. [250Hz – 4kHz]. The coefficients of the SH decomposition are then processed by some beamforming methods, in order to compute the DRIR in any direction around the spherical array. Time and 3D space representations can be generated. The results obtained in some rooms are illustrated in this paper: it is shown that the combination of the ‘delay-and-sum’ and ‘minimum-variance distorsionless response’ beamforming methods is particularly well suited for the analysis of DRIRs. [less ▲]

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See detailMeasurement of apolipoproteins B and A by radial immunodiffusion: methodological assessment and clinical applications.
Cano, M. D.; Gonzalvo, C.; Scheen, André ULg et al

in Annales de Biologie Clinique (1994), 52(9), 657-61

The clinical evaluation of apolipoproteins is of interest in order to characterize the risk profile for ischemic heart disease both in normolipidemic and hyperlipidemic subjects. In the non-specialized ... [more ▼]

The clinical evaluation of apolipoproteins is of interest in order to characterize the risk profile for ischemic heart disease both in normolipidemic and hyperlipidemic subjects. In the non-specialized and/or small practice clinical laboratory, the measurement of some apolipoproteins can be undertaken by simple methods of immunological analysis, among which radial immunodiffusion can be of interest due to its simplicity of use and because it does not require specific equipment. In this work several methodological questions concerning the measurement of plasma apolipoproteins B and A by radial immunodiffusion have been addressed; the results show that this method is particularly reliable for the apo B assay. Regression analysis between values obtained with radial immunodiffusion and radioimmunoassay was r = 0.972 for apo B and r = 0.782 for apo A. The recovery rate was above 90% for both apolipoproteins (93.8% for apo B and 99.5% for apo A). The inter and intraassay coefficients of variation were below 5%, and the detection limits were estimated as 9.6 mg/dl for apo A and 6.9 mg/dl for apo B. Neither the ingestion of a standard breakfast (500 Cal, 17 g fat, 120 mg cholesterol) 2 h prior to testing nor freezing the sample significantly affected the measurement of apolipoproteins B and A. Mean plasma concentrations of both apolipoproteins measured by radial immunodiffusion in normo and hyperlipidemic subjects are also presented. [less ▲]

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See detailMEASUREMENT OF AROMATIC CHOLINE ESTERS IN RAPESEED BY HPLC
Mabon, N.; Wathelet, Jean-Paul ULg; Marlier, M.

Poster (1999)

Aromatic choline esters are natural compounds occurring in Brassicaceae especially in rapeseed among whom the most important is called sinapine (choline ester of the 3,5-dimethoxy-4 hydroxycinnamic acid ... [more ▼]

Aromatic choline esters are natural compounds occurring in Brassicaceae especially in rapeseed among whom the most important is called sinapine (choline ester of the 3,5-dimethoxy-4 hydroxycinnamic acid). Choline esters are easily hydrolysed by entero bacteria in digestive tractus giving the correspondent acid and a choline molecule. Choline could then be broken down, by a deaminase, into trimethylamine, compound inducing a negative flavour ("fishy odour") in the milk, the meat or in yolk. So, the method improved in our laboratory is a power tool for breeders and other scientists who would like to evaluate individual aromatic choline esters in seeds or meals. Seeds (10 g) are first ground in a coffee mill (20 sec). 200 mg of ground seeds are weighed in a test tube and then placed in a water bath (75°C). Then 10 ml of boiling methanol/acetic acid (0.05M) mixture (70/30) are added plus 0.5 ml of internal standard solution (3,5-dimethoxybenzoic choline ester, 10 µmol/ml).The heterogeneous content is stirred with a magnetic stirrer for 10 min. Only one extraction step is necessary to obtain good results. Then, 1 ml of crude extract is purified with a cation exchange column (CM Sephadex C25-120). Aromatic choline esters are eluted with acetic acid 1N. Separation and quantification of individual choline esters are further realised by high performance liquid chromatography with an Inertsil 5 ODS-2 (3 x 250 mm, 5 µm) using a ternary solvent gradient (water-acetonitrile-phosphate buffer: NaH2PO4, 20 mM at pH 2 with o-phosphoric acid). In these optimised chromatographic conditions, the choline esters are separated and quantified. The retention times and the response factors have been determinated for the 36 different choline esters (benzoic or cinnamic structures with hydroxy or methoxy groups in ortho, para or meta position) synthesised in our laboratory. [less ▲]

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See detailMeasurement of carbon content in coal with laser—induced breakdown spectroscopy
Li, Ping; Lu, Jidong; Xie, Chengli et al

in Journal of Applied Optics (2008), 28(6), 756-759

The feasibility of rapid quantitative analysis of coal by Laser—Induced Breakdown Spectroscopy technique was studied.The calibration curve method for LIBS quantitative analysis is introduced.Five coal ... [more ▼]

The feasibility of rapid quantitative analysis of coal by Laser—Induced Breakdown Spectroscopy technique was studied.The calibration curve method for LIBS quantitative analysis is introduced.Five coal samples were selected as investigation subjects,the carbon plasma line of 505.2 nm was chosen as analysis spectrum line,and the carbon content of coal was analyzed quantitatively with delay of 0.8us, 1.2us, 1.6 us, 2.0 us and 2.4us. The results were compared with the results measured with Element Analysis Instrument.The error measured in1.6us delay was the minimum ,the effect of delay time on the quantitative analysis was analyzed.The results indicate that LIBS has a great potential in fast analysis of coal content. [less ▲]

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See detailMEASUREMENT OF CATTLE METHANE EMISSIONS USING THE EDDY-COVARIANCE TECHNIQUE
Dumortier, Pierre ULg; Aubinet, Marc ULg; Debacq, Alain ULg et al

Poster (2014)

Methane emissions account for 8% of the EU-15 GHG emissions and livestock generates approximately half of these emissions [1]. Recent technological advances in spectroscopy now permit methane flux ... [more ▼]

Methane emissions account for 8% of the EU-15 GHG emissions and livestock generates approximately half of these emissions [1]. Recent technological advances in spectroscopy now permit methane flux measurement using eddy covariance. Methane fluxes exchanged by a pasture were measured continuously since June 2012 at the Dorinne Terrestrial Observatory in Belgium. During grazing periods, fluxes are dominated by enteric fermentation. Methane emissions were found strongly related to cattle stocking rate. When fluxes are integrated over large periods and assuming a random position of cows on the pasture, emission per LSU (Livestock Unit) was found to be 53±3 kg CH4 year-1 LSU-1. Recently, cattle position on the grassland was monitored continuously using GPS devices and combined with a footprint analysis [2] to derive more precisely the CH4 emission per LSU. A first experiment with a stocking rate close to 0.7 LSU ha-1 validated the approach and ended in a mean emission per head of 51±10 kg CH4 year-1 head-1. This approach also allows estimating emissions per head at the hourly scale and therefore opens the possibility of studying the circadian emission cycle and to link emissions to feeding behavior of the animal and feed quality. [less ▲]

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See detailMeasurement of cerebrospinal fluid albumin in healthy dogs
Ramery, Eve ULg; Girod, Maud ULg; Allerton, Fergus et al

in Veterinary Clinical Pathology (2013)

Background: Measurement of CSF albumin aids diagnosis in human medicine but technical difficulties related to its low CSF concentration prohibit its routine use in veterinary medicine. High-resolution ... [more ▼]

Background: Measurement of CSF albumin aids diagnosis in human medicine but technical difficulties related to its low CSF concentration prohibit its routine use in veterinary medicine. High-resolution electrophoresis (HRE) has been described but often results in non-interpretable integration profiles preventing albumin determination. Fraction quantification using HRE may be more precise after concentration (cHRE) using a membrane microconcentrator technique but has not been evaluated in CSF with total protein levels below 20mg/dL. Immunoturbidimetry is routinely used for human CSF albumin measurement and was recently applied on canine samples with encouraging results. Objective: The purpose of this study was to compare HRE (including the use of a concentration step) and immunoturbidimetric assay for the measurement of albumin levels in normal canine CSF. Methods: 30 CSF specimens from 15 healthy dogs were evaluated. CSF total protein was measured by the pyrogallol red methoda and CSF albumin was determined by HREb (n=15), cHREc (n=30) and immunoturbidimetric assayd (n=30). Validation of the human immunoturbidimetric assay was performed using a purified canine albumin standarde. Results: Mean CSF total protein was 17.5 (range 7-39) mg/dL. HRE integration profiles were non-interpretable in all unconcentrated specimens. However, clear distinction of the major protein fractions was achieved for all cHRE specimens. CSF albumin levels were measureable in 29/30 specimens using immunoturbidimetry. Excellent correlation (Pearson r=0.92, p<0.001) was found between the two techniques. Conclusion: Immunoturbidimetry and cHRE may be used for routine measurement of CSF albumin. [less ▲]

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See detailMeasurement of circulating 25-hydroxyvitamin D: A historical review
Delvin, Edgar; LE GOFF, Caroline ULg; CAVALIER, Etienne ULg et al

in Practical Laboratory Medicine (in press)

The constantly increasing requests for the measurement of serum 25-hydroxyvitamin D over the last years has led reagent manufacturers to market different automated and semi-automated methods, that being ... [more ▼]

The constantly increasing requests for the measurement of serum 25-hydroxyvitamin D over the last years has led reagent manufacturers to market different automated and semi-automated methods, that being unfortunately not fully harmonized, yield different results. Liquid chromatography coupled to tandem mass spectrometry (LC/MS2) has more recently been introduced. This approach allows the distinction between the two forms of 25-hydroxyvitamin D and to measure other metabolites. This approach also requires harmonization to curtail the differences between the different analytical methods. To meet this requirement, the American National Institutes of Health (NIH), the CDC (Centre for Disease Control and Prevention) in Atlanta, the NIST (National Institute of Standards and Technology) and the vitamin D Reference laboratory of Ghent University have pooled their expertise to develop a standardization program. This article reviews the main elements and the difficulties of the automated and semi-automated methods for 25-hydroxyvitamin D, from sample preparation to the analytical phase, as well as those related to mass spectrometry. It also addresses the issues related to the clinical decision thresholds and the possibility of measurements in different biological liquids. [less ▲]

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See detailMeasurement of Dechloranes and PBDEs in European Human Serum
Brasseur, Catherine ULg; Focant, Jean-François ULg

Scientific conference (2013, May)

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See detailMeasurement of dielectric properties at low temperatures: application to the study of magnetoresistive manganite/ insulating oxide bulk composites
Vanderbemden, Philippe ULg; Rivas-Murias, Beatriz; Lovchinov, Vassil et al

in Journal of Physics: Conference Series (2010), 253

In this paper, we report low temperature dielectric measurements of bulk composite electroceramic samples containing a colossal magnetoresistive (CMR) manganite phase (La0.7Ca0.3MnO3 [abbreviated LCMO ... [more ▼]

In this paper, we report low temperature dielectric measurements of bulk composite electroceramic samples containing a colossal magnetoresistive (CMR) manganite phase (La0.7Ca0.3MnO3 [abbreviated LCMO]) and an insulating phase (Mn3O4). Details of the experimental system are given and possible experimental artefacts due to moisture are outlined. For a LCMO volume fraction of ~ 16%, the permittivity of the LCMO/ Mn3O4 composite at T = 50 K is found to be much higher than that of pure Mn3O4 and magnetic field dependent. This effect is related to an extrinsic space charge polarization mechanism between the insulating phase (Mn3O4) and the conducting magnetoresistive phase (LCMO). [less ▲]

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