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
See detailLe néant comme fondement et comme liberté
Jamin, Jérôme ULg

Article for general public (2007)

Detailed reference viewed: 4 (3 ULg)
Peer Reviewed
See detailNear and far infrared transitions of Fe2+ in cubic II-VI semiconductors: Dynamic Jahn-Teller interaction
Colignon, David ULg; Kartheuser, Eduard ULg

in Zeitschrift Fur Physikalische Chemie-International Journal Of Research In Physical Chemistry & Chemical Physics (1997), 201(Part 1), 119-126

Optical-absorption and emission measurements of doubly ionized iron in CdTe, ZnTe, ZnSe and ZnS have been analyzed by means of a vibronic coupling model. The model [1] is based on the crystal-field theory ... [more ▼]

Optical-absorption and emission measurements of doubly ionized iron in CdTe, ZnTe, ZnSe and ZnS have been analyzed by means of a vibronic coupling model. The model [1] is based on the crystal-field theory, including spin-orbit and spin-spin interactions and Jahn-Teller couplings of the orbital doublet and triplet states of Fe2+ with overtones of phonons of Gamma(3) and Gamma(5) symmetries, respectively. Starting from the 25 spin-orbit wave functions appropriate to the orbital doublet and triplet manifolds, the symmetry-adapted vibronic basis is constructed and used to diagonalize the Hamiltonian matrix formed out of five blocks of symmetry Gamma(1), Gamma(2), Gamma(3), Gamma(4) and Gamma(5). Phonon overtones up to N=6 for the Gamma(3) phonon and up to N=10 for the Gamma(5) phonon were included to ensure convergence of the energy values and eigenfunction of the vibronic states. The available measured positions and relative intensities of the spectral lines in the near and far infrared are accounted for within the experimental accuracy. It is shown that the above mentioned iron based II-VI compounds (ZnS:Fe2+ excepted) exhibit a strong dynamic Jahn-Teller coupling of the upper orbital triplet state with phonons of Gamma(5) symmetry and that the spin-orbit interaction between the orbital doublet and triplet states of Fe2+ is essential to explain the data. [less ▲]

Detailed reference viewed: 44 (6 ULg)
Peer Reviewed
See detailNear Fatal Respiratory Distress Following Massive Ether Intravenous Injection
Lambermont, Bernard ULg; Dubois, Colette ULg; Fraipont, V. et al

in Intensive Care Medicine (1998), 24(6), 624-5

To the best of our knowledge, no case of ether-induced acute respiratory distress syndrome (ARDS) has been published as yet. A 36-year-old female developed pneumonitis which showed all the characteristics ... [more ▼]

To the best of our knowledge, no case of ether-induced acute respiratory distress syndrome (ARDS) has been published as yet. A 36-year-old female developed pneumonitis which showed all the characteristics of a chemical-associated ARDS due to intravenous self-administration of ether: the hemodynamic investigation demonstrated a normal blood flow pattern with low left-heart filling pressure while the anteroposterior roentgenogram evidenced disseminated bilateral lung edema. Advanced symptomatic respiratory support including inhaled nitric oxide and steroidal anti-inflammatory use was the treatment of choice. [less ▲]

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailNear infrared and Raman spectroscopy as Process Analytical Technology tools for the manufacturing of silicone-based drug reservoirs
Mantanus, Jérôme ULg; Rozet, Eric ULg; Van Butsele, K. et al

in Analytica Chimica Acta (2011), 699

Using Near Infrared (NIR) and Raman spectroscopy as PAT tools, 3 critical quality attributes of a silicone-based drug reservoir were studied. First, the Active Pharmaceutical Ingredient (API) homogeneity ... [more ▼]

Using Near Infrared (NIR) and Raman spectroscopy as PAT tools, 3 critical quality attributes of a silicone-based drug reservoir were studied. First, the Active Pharmaceutical Ingredient (API) homogeneity in the reservoir was evaluated using Raman spectroscopy (mapping): the API distribution within the industrial drug reservoirs was found to be homogeneous while API aggregates were detected in laboratory scale samples manufactured with a non optimal mixing process. Second, the crosslinking process of the reservoirs was monitored at different temperatures with NIR spectroscopy. Conformity tests and Principal Component Analysis (PCA) were performed on the collected data to find out the relation between the temperature and the time necessary to reach the crosslinking endpoints. An agreement was found between the conformity test results and the PCA results. Compared to the conformity test method, PCA had the advantage to discriminate the heating effect from the crosslinking effect occurring together during the monitored process. Therefore the 2 approaches were found to be complementary. Third, based on the HPLC reference method, a NIR model able to quantify the API in the drug reservoir was developed and thoroughly validated. Partial Least Squares (PLS) regression on the calibration set was performed to build prediction models of which the ability to quantify accurately was tested with the external validation set. The 1.2 % RMSEP of the NIR model indicated the global accuracy of the model. The accuracy profile based on tolerance intervals was used to generate a complete validation report. The 95 % tolerance interval calculated on the validation results indicated that each future result will have a relative error below ±5 % with a probability of at least 95 %. In conclusion, 3 critical quality attributes of silicone-based drug reservoirs were quickly and efficiently evaluated by NIR and Raman spectroscopy. [less ▲]

Detailed reference viewed: 73 (19 ULg)
Full Text
See detailNear infrared reflectance spectroscopy for estimating soil characteristics useful in the diagnosis of soil fertility
Genot, Valérie ULg; Colinet, Gilles ULg; Bock, Laurent ULg et al

in Proceedings of the 14th International Conference on NIR Spectroscopy (2009, November)

Detailed reference viewed: 30 (2 ULg)
Full Text
Peer Reviewed
See detailNear infrared reflectance spectroscopy for estimating soil characteristics valuable in the diagnosis of soil fertility
Genot, Valérie ULg; Colinet, Gilles ULg; Bock, Laurent ULg et al

in Journal of Near Infrared Spectroscopy [=JNRIS] (2011), 19(2), 117-138

Soil fertility diagnostics rely not only upon measurement of available nutrients but also upon the soil’s ability to retain these nutrients. Near-infrared reflectance spectroscopy (NIRS) is a rapid and ... [more ▼]

Soil fertility diagnostics rely not only upon measurement of available nutrients but also upon the soil’s ability to retain these nutrients. Near-infrared reflectance spectroscopy (NIRS) is a rapid and non-destructive analytical technique which allows to simultaneously estimate standard soil characteristics and does not require use of chemicals. Previous studies showed that NIRS could be used in local contexts to predict soil properties. The main goal of our research is to build a methodological framework for the use of NIRS at a more global scale. The specific goals of this study were (i) to identify the best spectra treatment and processing –LOCAL versus GLOBAL regression- methods, (ii) to compare NIRS performances to standard chemical protocols and (iii) to evaluate the ability of NIRS to predict soil total organic carbon (TOC), total Nitrogen (TN), clay content and cationic exchange capacity (CEC) for a wide range of soil conditions. We scanned 1,300 samples representative of main soil types of Wallonia under crop, grassland or forest. Various sample preparations were tested prior to NIRS measurements. The most appropriate options were selected according to ANOVA analysis and multiple means comparisons of the spectra principal components. Fifteen pre-treatments were applied to a calibration set and the prediction accuracy was evaluated for GLOBAL and LOCAL modified partial least square (MPLS) regression models. The LOCAL MPLS calibrations showed very encouraging results for all the studied characteristics. On average, for crop soil samples, the prediction coefficient of variation (CVp) was close to 15% for TOC content, 7% for TN content, and 10% for clay content and CEC. The comparisons of repeatability and reproducibility of both NIRS and standard methods showed that NIRS is as reliable as reference methods. Prediction accuracy and technique repeatability allow the use of NIRS within the framework of the soil fertility evaluation and its replacement of standard protocols. LOCAL MPLS can be applied within global datasets, such as the International global soil spectral library. However, the performance of LOCAL MPLS is linked to the number of similar spectra in the dataset and more standard measurements are needed to characterize the least widespread soils. [less ▲]

Detailed reference viewed: 122 (22 ULg)
Full Text
Peer Reviewed
See detailNear Infrared Spectroscopy for Non-Invasive Assessment of Intracranial Haemoglobin Oxygenation in an in Vitro Model of the Calf Head
Pringle, John; Art, Tatiana ULg; Lekeux, Pierre ULg

in Research in Veterinary Science (1998), 65(2), 103-109

An in vitro model of the calf head was used to examine the ability of near infrared spectroscopy (NIRS) to non-invasively determine oxygenation events within the calf head. The brains were removed from 16 ... [more ▼]

An in vitro model of the calf head was used to examine the ability of near infrared spectroscopy (NIRS) to non-invasively determine oxygenation events within the calf head. The brains were removed from 16 calf skulls and replaced with oxygenated dilutions of calf blood that had the oxygen progressively decreased from PO2 > 110 mmHg to < 10 mmHg. Appropriate placement of the lighting source and sensor (optodes) was examined, as were the influences of skull thickness and overlying skin of the skull (including colour). The changes in haemaglobin oxygenation in the model calf head, as observed by NIRS, were highly correlated to PO2 changes in all 16 calf skulls examined (mean r2=0.91, range 0.71 to 0.99). There was a trend for optode positioning to achieve optimal NIRS signals over the middle of the frontal bone in a longitudinal axis and with optodes spaced 4 cm apart, but with the large variation between calf heads this was not shown to be significantly different from other sites tested. The presence of skin over the skull had a significant damping effect on the NIRS signal when compared with the bare skull (P<0.01) but it was not possible to detect a difference in this damping effect between black and white coloured skin. All but the two thickest skulls (13 and 14 mm frontal bone thickness) appeared to allow sufficiently strong NIRS signals of changes in haemoglobin oxygenation. This study showed that NIRS can be used for non-invasive study of oxygenation events within the cranial cavity of calves, and established some guidelines and limitations for its use in this species. [less ▲]

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailNear infrared spectroscopy in large animals: optical pathlengh and influence of hair covering and epidemal pigmentation
Pringle, J.; Roberts, C.; Kohl, M. et al

in Veterinary Journal (1999), 158

The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues ... [more ▼]

The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues at four wavelengths in the NIR range were subsequently determined. Black hair covering and black or dark-coloured hooves prevented NIR light from penetration sufficient for conduction of pathlength or NIR spectroscopy measurements. Non-pigmented hair covering of the head did not appear to be a barrier to successful NIR light transmission. Tissues sufficiently transparent to NIR light had the differential pathlength factor (DPF, i.e. the ratio of the observed light pathlength and the geometric light source-detector separation) of NIR light determined by intensity modulated spectroscopy at the wavelengths 744, 806, 834 and 860 nm. Horse gluteal muscles had DPFs of 6.2, 6.2, 6.0, and 5.6, whereas forelimb muscles had DPF of 4.7, 4.4, 4.5 and 3.9 at the respective wavelengths. Sheep heads had DPF of 7.2 +/- 0.3, 5.8 +/- 0.5, 5.5 +/- 0.4 and 4.4 +/- 0.6 (+/- SEM) for the above respective wavelengths, of which the pathlengths all differed significantly from the other, except for between 806 and 834 nm, and 834 and 860 nm. The DPF of horse hooves were 4.8 +/- 0.1, 4.8 +/- 0.1, 4.7 +/- 0.1 and 4.4 +/- 0.1 (SEM) for the above noted wavelengths, of which the pathlength at 744 and 806 nm differed from the pathlength at 860 nm (P>0.05). These results show that NIRS is possible through lighter pigmented hair and epidermal tissues, and provide DPFs of horse feet and muscle and the sheep head that enables quantitative NIRS in these species. [less ▲]

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailNear Infrared Spectroscopy of the Normal Bovine Claw
Pringle, John; Uystepruyst, Christophe; Art, Tatiana ULg et al

in Veterinary Journal (1998), 156(2), 155-158

Detailed reference viewed: 12 (1 ULg)
Full Text
See detailNear Optimal Closed-Loop Control. Application to Electric Power Systems
Ernst, Damien ULg

Doctoral thesis (2003)

Detailed reference viewed: 45 (17 ULg)
Full Text
See detailNear real time assessment of the ionosphere effect on high accuracy GNSS applications which require ambiguity resolution
Lejeune, Sandrine; Warnant, René ULg

in Proceedings of the 2nd COST296 Workshop (2006, October)

Detailed reference viewed: 14 (2 ULg)
See detailNear real time assessment of the Space Weather effect on navigation based on the DGPS technique
Lejeune, Sandrine; Warnant, René ULg; Barré, Aline et al

Conference (2005)

Detailed reference viewed: 9 (0 ULg)
See detailNear real-time assessment of the ionospheric effect on navigation based on DGPS corrections
Lejeune, Sandrine; Warnant, René ULg; Barré, Aline et al

in Proceedings of Beacon Satellite Symposium 2004 (2005)

Detailed reference viewed: 12 (1 ULg)
See detailNear real-time evaluation of the EGNOS ionospheric correction at mid-latitude
Bavier, Michaël; Warnant, René ULg; Barré, Aline et al

in Proceedings of Beacon Satellite Symposium 2004 (2005)

Detailed reference viewed: 20 (1 ULg)
See detailNear real-time validation of GPS-TEC using ionosonde TEC at Dourbes
Warnant, René ULg; Nebdi, Hamid; Pottiaux, Eric

Report (2003)

Detailed reference viewed: 21 (2 ULg)
Full Text
Peer Reviewed
See detailNear- and mid-infrared colours of star-forming galaxies in European Large Area ISO Survey fields
Vaisanen, Petri; Morel, Thierry ULg; Rowan-Robinson, M. et al

in Monthly Notices of the Royal Astronomical Society (2002), 337

We present J- and K-band near-infrared (near-IR) photometry of a sample of mid-infrared (mid-IR) sources detected by the Infrared Space Observatory (ISO) as part of the European Large Area ISO Survey ... [more ▼]

We present J- and K-band near-infrared (near-IR) photometry of a sample of mid-infrared (mid-IR) sources detected by the Infrared Space Observatory (ISO) as part of the European Large Area ISO Survey (ELAIS) and study their classification and star-forming properties. We have used the Preliminary ELAIS Catalogue for the 6.7-μm (LW2) and 15-μm (LW3) fluxes. All of the high-reliability LW2 sources and 80 per cent of the LW3 sources are identified in the near-IR survey reaching K~ 17.5 mag. The near-IR/mid-IR flux ratios can effectively be used to separate stars from galaxies in mid-IR surveys. The stars detected in our survey region are used to derive a new accurate calibration for the ELAIS ISOCAM data in both the LW2 and LW3 filters. We show that near- to mid-IR colour-colour diagrams can be used to classify galaxies further, as well as to study star formation. The ELAIS ISOCAM survey is found mostly to detect strongly star-forming late-type galaxies, possibly starburst-powered galaxies, and it also picks out obscured active galactic nuclei. The ELAIS galaxies yield an average mid-IR flux ratio LW2/LW3 = 0.67 +/- 0.27. We discuss the f[SUB]ν[/SUB](6.7 μ m)/f[SUB]ν[/SUB](15 μ m) ratio as a star formation tracer using ISO and IRAS data of a local comparison sample. We find that the f[SUB]ν[/SUB](2.2 μ m)/f[SUB]ν[/SUB](15 μ m) ratio is also a good indicator of activity level in galaxies and conclude that the drop in the f[SUB]ν[/SUB](6.7 μ m)/f[SUB]ν[/SUB](15 μ m) ratio seen in strongly star-forming galaxies is a result of both an increase of 15-μm emission and an apparent depletion of 6.7-μm emission. Near-IR together with the mid-IR data make it possible to estimate the relative amount of interstellar matter in the galaxies. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Peer Reviewed
See detailNear-Death Experiences : Real or imagined memories?
Thonnard, Marie ULg; Laureys, Steven ULg; Brédart, Serge ULg et al

Poster (2010, September)

Detailed reference viewed: 83 (11 ULg)