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See detailOptical Device For Projection Display System
Habraken, Serge ULg

Patent (2002)

An optical system to track a laser pointer in a multi media presentation. The information is used for dispaying symbols or activation of controls

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See detailThe optical EHD method applied to the study of ageing of biodegradable oils
Cloesen, C.; Kabuya, A.; Bozet, Jean-Luc ULg

in Journal of Synthetic Lubrication (1998), 15(1), 1-12

In the present study, modifications of the lubricating properties of vegetable oils, which had undergone accelerated ageing, were quantified, using the optical EHD method. Each oil sample was examined in ... [more ▼]

In the present study, modifications of the lubricating properties of vegetable oils, which had undergone accelerated ageing, were quantified, using the optical EHD method. Each oil sample was examined in an optical viscometer in order to measure film thickness vs. contact speed. From these results the pressure—viscosity coefficient was calculated, by adjusting theoretical values. The modifications were related to molecular changes, which were observed with various tools of chemical analysis, including gel permeation chromatography (GPC). [less ▲]

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See detailOptical evolution of Nova Ophiuchi 2007 = V2615 Oph
Munari, U.; Henden, A.; Valentini, Marica ULg et al

in Monthly Notices of the Royal Astronomical Society (2008), 387

The moderately fast Nova Oph 2007 reached maximum brightness on 2007 March 28 at V = 8.52, B - V = +1.12, V - R[SUB]C[/SUB] = +0.76, V - I[SUB]C[/SUB] = +1.59 and R[SUB]C[/SUB] - I[SUB]C[/SUB] = +0.83 ... [more ▼]

The moderately fast Nova Oph 2007 reached maximum brightness on 2007 March 28 at V = 8.52, B - V = +1.12, V - R[SUB]C[/SUB] = +0.76, V - I[SUB]C[/SUB] = +1.59 and R[SUB]C[/SUB] - I[SUB]C[/SUB] = +0.83, after fast initial rise and a pre-maximum halt lasting a week. Decline times were t[SUP]V[/SUP][SUB]2[/SUB] = 26.5, t[SUP]B[/SUP][SUB]2[/SUB] = 30, t[SUP]V[/SUP][SUB]3[/SUB] = 48.5 and t[SUP]B[/SUP][SUB]3[/SUB] = 56.5 d. The distance to the nova is d = 3.7 +/- 0.2 kpc, the height above the Galactic plane is z = 215 pc, the reddening is E(B - V) = 0.90 and the absolute magnitude at maximum is M[SUP]max[/SUP][SUB]V[/SUB] = -7.2 and M[SUP]max[/SUP][SUB]B[/SUB] = -7.0. The spectrum four days before maximum resembled a F6 supergiant, in an agreement with broad-band colours. It later developed into that of a standard `FeII'-class nova. Nine days past maximum, the expansion velocity estimated from the width of Hα emission component was ~730 km s[SUP]-1[/SUP], and the displacement from it of the principal and diffuse-enhanced absorption systems was ~650 and 1380 km s[SUP]-1[/SUP], respectively. Dust probably formed and disappeared during the period from 82 to 100 d past maximum, causing (at peak dust concentration) an extinction of ΔB = 1.8 mag and an extra ΔE(B - V) = 0.44 reddening. [less ▲]

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See detailThe optical gravitational lens experiment
Surdej, Jean ULg; Refsdal, S.; Pospieszalska-Surdej, Anna ULg

in Surdej, Jean; Fraipont-Caro, D.; Gosset, E. (Eds.) et al Proceedings of the 31st Liege International Astrophysical Colloquium (LIAC 93) (1993)

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See detailOptical imaging of gravitational lenses B1422+231
Remy, M.; Surdej, Jean ULg; Smette, A. et al

in Surdej, Jean; Fraipont-Caro, D.; Gosset, Eric (Eds.) et al Liege International Astrophysical Colloquia,Gravitational Lenses in the Universe (1993)

We report here on some of the major developments achieved on optical observations of gravitational lenses since the last conference devoted to 'Gravitational Lensing'.

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See detailOptical imaging of the gravitational lens system B 1422+231
Remy; Surdej, Jean ULg; Smette, A. et al

in Astronomy and Astrophysics (1993), 278

Direct optical images (Bessel V, R and Gunn i; average seeing of 0.88 seconds) of B1422+231, obtained in March 1993 at European Southern Observatory (ESO) (La Silla), have been decomposed by fitting ... [more ▼]

Direct optical images (Bessel V, R and Gunn i; average seeing of 0.88 seconds) of B1422+231, obtained in March 1993 at European Southern Observatory (ESO) (La Silla), have been decomposed by fitting multiple Point Spread Functions (PSFs). We detect the optical counterparts of the four known radio point-like components. No additional optical image is found, but due to the compactness of the configuration, our detection limit for additional point sources is rather low (19.3 in R). The deduced positions and photometry of the four optical components agree pretty well with the radio and IR observations and this study provides further evidence supporting the gravitational lens origin of B1422+231. [less ▲]

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See detailOptical methods for non-contact measurements of membranes
Roose, Stéphane ULg; Stockman, Yvan ULg; Rochus, Pierre ULg et al

in Acta Astronautica (2009), 65(9-10), 1317-1329

Structures for space applications very often suffer stringent mass constraints. Lightweight structures are developed for this purpose, through the use of deployable and/or inflatable beams, and thin-film ... [more ▼]

Structures for space applications very often suffer stringent mass constraints. Lightweight structures are developed for this purpose, through the use of deployable and/or inflatable beams, and thin-film membranes. Their inherent properties (low mass and small thickness) preclude the use of conventional measurement methods (accelerometers and displacement transducers for example) during on-ground testing. In this context, innovative non-contact measurement methods need to be investigated for these stretched membranes. The object of the present project is to review existing measurement systems capable of measuring characteristics of membrane space-structures such as: dot-projection videogrammetry (static measurements), stereo-correlation (dynamic and static measurements), fringe projection (wrinkles) and 3D laser scanning vibrometry (dynamic measurements). Therefore, minimum requirements were given for the study in order to have representative test articles covering a wide range of applications. We present test results obtained with the different methods on our test articles. [less ▲]

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See detailOPTICAL MULTICHANNEL ANALYSIS OF PROTOCHLOROPHYLLIDE PHOTOTRANSFORMATION IN DETERGENT-SOLUBILIZED ETIOPLAST MEMBRANES OF WHEAT
Franck, Fabrice ULg; OUAZZANI, M. A.; DUJARDIN, E. et al

in Zeitschrift Fur Naturforschung C-A Journal Of Biosciences (1994), 49(1-2), 125-131

Extracts of wheat etioplast membranes obtained after treatment with 7 mM n-octyl-beta-D-glucopyranoside (OG), n-dodecyl-beta-D-maltoside (DM) or Triton X-100 contained the three spectral forms of Pchlide ... [more ▼]

Extracts of wheat etioplast membranes obtained after treatment with 7 mM n-octyl-beta-D-glucopyranoside (OG), n-dodecyl-beta-D-maltoside (DM) or Triton X-100 contained the three spectral forms of Pchlide (the photoactive Pchlide(638) and Pchlide(638) and the inactive Pchlide(650)) in various relative amounds. The OG extract had a Pchlide composition close to that of the intact membranes whereas the DM extract was enriched in Pchlide(638) and the Triton extract was enriched in Pchlide(630). Measurements of the kinetics of phototransformation and of time-resolved absorbance spectra during phototransformation in continuous Light shows that the inactive Pchlide(630) is in fact slowly transformed to Chlide, especially in the Triton extract where this form is more abundant. Addition of NADPH favours the phototransformation of Pchlide(630) and the slow regeneration of Pchlide(638) and Pchlide(650) from Pchlide(630) in darkness after illumination. No such regeneration was however observed in the Triton extract. NADPH had only slight effects on the Chlide shift towards shorter wavelengths after phototransformation in solubilized membranes. [less ▲]

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See detailOptical non-linearity in disperse red 1 dye-doped sol-gel
Rosso, Vanessa ULg; Loicq, Jerôme ULg; Renotte, Yvon ULg et al

in Journal of Non-Crystalline Solids (2004), 342(1-3), 140-145

A third-order non-linear optical effect, the optical Kerr effect, was studied in DR1-doped sol-gel using the Z-scan method which allows studying both processes of non-linear absorption and refraction. The ... [more ▼]

A third-order non-linear optical effect, the optical Kerr effect, was studied in DR1-doped sol-gel using the Z-scan method which allows studying both processes of non-linear absorption and refraction. The materials under study are sol-gel substrates, amorphous silica glasses doped by the azo-dye Disperse Red 1. Modifying the conditions of the sol-gel synthesis, in particular the pH of the catalytic medium, enabled us to vary the morphology of the sol-gel substrate. Non-linear effects of various amplitudes were observed in so-gel substrates of various porosities, involving different non-linear mechanisms. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailOptical observations of comet Hale-Bopp (C/1995 O1) at large heliocentric distances before perihelion.
Rauer, H.; Arpigny, Claude ULg; Boehnhardt, H. et al

in Science (1997), 275

The activity of comet Hale-Bopp (C/1995 O1) was monitored monthly by optical imaging and long-slit spectroscopy of its dust and gas distribution over heliocentric distances of 4.6 to 2.9 AU. The observed ... [more ▼]

The activity of comet Hale-Bopp (C/1995 O1) was monitored monthly by optical imaging and long-slit spectroscopy of its dust and gas distribution over heliocentric distances of 4.6 to 2.9 AU. The observed band intensities of the NH[SUB]2[/SUB] radical and the H[SUB]2[/SUB]O[SUP]+[/SUP] ion cannot be explained by existing models of fluorescence excitation, warranting a reexamination of the corresponding production rates, at least at large heliocentric distances. Comparing the production rate of the CN radical to its proposed parent, HCN, shows no evidence for the need of a major additional source for CN in Hale-Bopp at large heliocentric distances. The dust and CN production rates are consistent with a significant amount of sublimation occurring from icy dust grains surrounding Hale-Bopp. [less ▲]

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See detailOptical Observations of Comet McNaught from La Silla
Snodgrass, C.; Fitzsimmons, A.; Jehin, Emmanuel ULg et al

in LPI contribution 1405 (2008)

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See detailOptical observations of gravitational lenses
Surdej, Jean ULg; Claeskens, Jean-François ULg; Hutsemekers, Damien ULg et al

in Kayser, Rainer; Schramm, Thomas; Nieser, Lars (Eds.) Proceedings of the Hamburg conference on ’Gravitational Lenses’, Lecture Notes in Physics 406 (1992)

We report here on some of the major developments achieved on optical observations of gravitational lenses since the last conference devoted to 'Gravitational Lensing'.

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See detailOptical polarization from AGN
Hutsemekers, Damien ULg

Conference (2015, May)

I review the optical polarization properties of both low- and high-luminosity AGN, focusing on the origin of the polarization and its relation to AGN properties, in particular the geometry of the ... [more ▼]

I review the optical polarization properties of both low- and high-luminosity AGN, focusing on the origin of the polarization and its relation to AGN properties, in particular the geometry of the scattering regions. The use of polarization to follow AGN orientations along the large-scale structures will also be discussed. [less ▲]

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See detailOptical polarization of 203 QSOs (Sluse+, 2005)
Sluse, Dominique ULg; Hutsemekers, Damien ULg; Lamy, H. et al

Textual, factual or bibliographical database (2004)

This Table contains linear polarization measurements (mainly in the V band) of 203 QSOs. First time measurements have been obtained for 184 objects. Among them 109 known radio emitters, 42 BAL and 1 ... [more ▼]

This Table contains linear polarization measurements (mainly in the V band) of 203 QSOs. First time measurements have been obtained for 184 objects. Among them 109 known radio emitters, 42 BAL and 1 gravitationally lensed QSO. (1 data file). [less ▲]

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See detailOptical Polarization of 47 QSOs (Lamy+, 2000)
Lamy, H.; Hutsemekers, Damien ULg

Textual, factual or bibliographical database (2000)

New broad-band linear polarization measurements are presented for a sample of 47 QSOs which includes 27 broad absorption line QSOs and 2 gravitational lens candidates. (2 data files).

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See detailOptical polarization of 47 quasi-stellar objects: The data
Lamy, H.; Hutsemekers, Damien ULg

in Astronomy and Astrophysics. Supplement Series (2000), 142

New broad-band linear polarization measurements are presented for a sample of 47 QSOs which includes 27 broad absorption line QSOs and 2 gravitational lens candidates. Tables 3 and 4 are also available in ... [more ▼]

New broad-band linear polarization measurements are presented for a sample of 47 QSOs which includes 27 broad absorption line QSOs and 2 gravitational lens candidates. Tables 3 and 4 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html Based on observations collected at the European Southern Observatory (ESO, La Silla). [less ▲]

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See detailThe optical polarization of radio-loud and radio-intermediate broad absorption line quasi-stellar objects
Hutsemekers, Damien ULg; Lamy, H.

in Astronomy and Astrophysics (2000), 358

On the basis of a sample of approximately 50 broad absorption line quasi-stellar objects (BAL QSOs), we investigate possible correlations between BAL QSO radio properties and other spectral ... [more ▼]

On the basis of a sample of approximately 50 broad absorption line quasi-stellar objects (BAL QSOs), we investigate possible correlations between BAL QSO radio properties and other spectral characteristics, including polarization. For this purpose new polarization data have been obtained. The main result of our statistical study is the absence of significant correlations between the radio-to-optical flux ratio R[SUP]star [/SUP] and all other quantities: the polarization p_0 of the continuum, the slope of the continuum, the balnicity and detachment indices which characterize the BAL profiles, and the terminal velocity of the flow v_max. The claimed anticorrelation between R[SUP]star [/SUP] and v_max is therefore not confirmed, as well as the correlation between R[SUP]star [/SUP] and p_0 predicted by some models. Although marginally significant, the only possible correlations occur for the BAL QSOs with low-ionization troughs. Based on observations collected at the European Southern Observatory (ESO, La Silla) [less ▲]

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See detailOptical properties and structure of nanodiamonds
Raty, Jean-Yves ULg; Galli, G.

in Journal of Electroanalytical Chemistry (2005), 584(1 Sp. Iss. SI), 9-12

We present a theoretical study of the structure and optical properties of nanodiamonds. Using ab initio molecular dynamics simulation, we confirm that quantum confinement effects become negligible between ... [more ▼]

We present a theoretical study of the structure and optical properties of nanodiamonds. Using ab initio molecular dynamics simulation, we confirm that quantum confinement effects become negligible between 2 and 3 nm in size. In this size domain, specific surface reconstructions occur upon sample dehydrogenation, leading to fullerene-capped structures, or 'bucky diamonds' with absorption spectra similar to the experiment. We finally show that the HOMO and LUMO states are interface states in the reconstructed structures. (c) 2004 Elsevier B.V.. All rights reserved. [less ▲]

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