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See detailPhotometry of p/ Halley 1982I
Sterken, C.; Manfroid, Jean ULg; Arpigny, Claude ULg

in Astronomy and Astrophysics (1987), 187

Abstract image available at: http://cdsads.u-strasbg.fr/abs/1987A&A...187..523S

Detailed reference viewed: 6 (0 ULg)
See detailPhotometry of southern stars in the uvby system.
Manfroid, Jean ULg

in Bulletin de la Société Royale des Sciences de Liège (1980), 49

Not Available

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See detailPhotometry of the G8V Star HD 192020
Vreux, Jean-Marie ULg; Manfroid, Jean ULg

in Information Bulletin on Variable Stars (1985), 2822

Not Available

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See detailPhotometry of the Wolf-Rayet Star HD 191765
Vreux, Jean-Marie ULg; Manfroid, Jean ULg

in Information Bulletin on Variable Stars (1985), 2821

Not Available

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See detailPhotometry with FORS
Freudling, W.; Møller, P.; Patat, F. et al

in Kaufer, A. (Ed.) The 2007 ESO Instrument Calibration Workshop (2008)

Photometric calibration observations are routinely carried out with all ESO imaging cameras in every clear night. The nightly zeropoints derived from these observations are accurate to about 10%. Recently ... [more ▼]

Photometric calibration observations are routinely carried out with all ESO imaging cameras in every clear night. The nightly zeropoints derived from these observations are accurate to about 10%. Recently, we have started the FORS Absolute Photometry Project (FAP) to investigate, if and how percent-level absolute photometric accuracy can be achieved with FORS1, and how such photometric calibration can be offered to observers. We found that there are significant differences between the sky-flats and the true photometric response of the instrument which partially depend on the rotator angle. A second order correction to the sky-flat significantly improves the relative photometry within the field. We demonstrate the feasibility of percent level photometry and describe the calibrations necessary to achieve that level of accuracy. [less ▲]

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See detailPhotometry with FORS at the ESO VLT
Freudling, W.; Romaniello, M.; Patat, F. et al

in Sterken, C. (Ed.) The Future of Photometric, Spectrophotometric and Polarimetric Standardization (2007, April 01)

ESO's two FOcal Reducer and low dispersion Spectrographs (FORS) are the primary imaging cameras for the VLT. Since they are not direct-imaging cameras, the accuracy of photometry which can routinely be ... [more ▼]

ESO's two FOcal Reducer and low dispersion Spectrographs (FORS) are the primary imaging cameras for the VLT. Since they are not direct-imaging cameras, the accuracy of photometry which can routinely be obtained is limited by significant sky concentration and other effects. Photometric standard observations are routinely obtained by ESO, and nightly zero points are computed mainly for the purpose of monitoring the instrument performance. The accuracy of these zero points is about 10%. Recently, we have started a program to investigate, if and how percent-level absolute photometric accuracy with FORS can be achieved. The main results of this project are presented in this paper. We first discuss the quality of the flatfields and how it can be improved. We then use data with improved flatfielding to investigate the usefulness of {Stetson standard fields} for FORS calibration and the accuracy which can be achieved. The main findings of the FORS Absolute Photometry Project program are as follows. There are significant differences between the sky flats and the true photometric response of the instrument which partially depend on the rotator angle. A second order correction to the sky flat significantly improves the relative photometry within the field. Percent level photometric accuracy can be achieved with FORS1. To achieve this accuracy, observers need to invest some of the assigned science time for imaging of photometric standard fields in addition to the routine nightly photometric calibration. [less ▲]

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See detailPhotometry, pole orientation and shape parameters of the minor planets 624 Hektor and 43 Ariadne
Detal, Alain ULg; Collette, P.; Hainaut, O. et al

in Brahic, A.; Gérard, J. C.; Surdej, J. (Eds.) "Observations and physical properties of small solar system bodies", 30th Liège International Astrophysical Colloquium, Institut d’Astrophysique, Liège (1992)

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See detailPhoton correlation spectroscopy for molecular self-assembly investigations
Razafindralambo, Hary ULg

Conference (2013, April 11)

The molecular self-assembly performance is among the most important functionalities of amphiphilic compounds in colloidal system areas. This aptitude is required in numerous applications, depending on ... [more ▼]

The molecular self-assembly performance is among the most important functionalities of amphiphilic compounds in colloidal system areas. This aptitude is required in numerous applications, depending on solubilization, hydrotropy, rheology, separation, loading and delivery, encountered in biological and industrial processes. The main physicochemical parameter predicting the capacity of amphiphiles to self-assembly in bulk liquid, aqueous (normal micelles) or non-aqueous phase (reverse micelles), is the pair critical micelle concentration (CMC) and temperature (CMT). A variety of methods based on surface tension, spectral changes, and electrical conductivity are commonly used for determining the value of CMC. The choice usually depends on the ionic or non-ionic nature of the amphiphilic compounds. In this communication, a standard Photon Correlation Spectroscopy (PCS), also known Light Scattering-based technique for CMC determination will be theoretically and practically described in details. Its particular interest for measuring the performance of non-ionic and very high hydrophobic tail, mono or disubstituted carbohydrate-based compounds, from C16 alkyl chain, will be demonstrated. Such a method is advantageous regarding the time, amount, and resolution required, but also for additional information on micelle size, aggregate number, and stability it may provide, compared to surface tension and electrical conductivity-based measurements. [less ▲]

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See detailThe photon wave function
Cugnon, Joseph ULg

in Open Journal of Microphysics (2011), 1

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See detailPhotoperiodic control of testosterone metabolism, plasma gonadotrophins, cloacal gland growth, and reproductive behavior in the Japanese quail.
Balthazart, Jacques ULg; Massa, R.; Negri-Cesi, P.

in General and Comparative Endocrinology (1979), 39(2), 222-35

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See detailPhotophysical investigation of Rose Bengal in aqueous sodium taurocholate solutions
Seret, Alain ULg; Van de Vorst, Albert

in Journal of Photochemistry and Photobiology B : Biology (1993), 17(1), 47-56

The photophysics of rose bengal has been studied in aqueous sodium taurocholate solutions with or without 0.6 mol NaCl dm−3. The ground and first excited singlet states solubilize only in the aggregates ... [more ▼]

The photophysics of rose bengal has been studied in aqueous sodium taurocholate solutions with or without 0.6 mol NaCl dm−3. The ground and first excited singlet states solubilize only in the aggregates formed by sodium taurocholate, whereas the first triplet state solubilizes both in the bulk phase and in the aggregates. A lower limit of the corresponding entry and exit rate constants ke and ks, respectively has been estimated: ke ≥ 5 X 106 dm3 mol−1 s−1 (2x107 dm3 mol−1 s−1 with 0.6 mol NaCl dm−3) and ks ≥ 105 s−1. The triplet state as well as the semioxidized radical react with the taurocholate anion. The former reaction leads to the formation of semireduced dye. The latter is responsible for the detection of only semioxidized radicals which move freely in the aqueous phase. The results are compared with those obtained previously in aqueous sodium dodecyl sulphate solutions and the possible biological implication is discussed. [less ▲]

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See detailPhotophysical properties of Eosin dianion in cationic micellar solutions
Seret, Alain ULg; Gandin, Ezio; Van de Vorst, Albert

in Archives Internationales de Physiologie et de Biochimie (1986, November), 94(4), 15

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See detailPhotophysique et couleur cutanée.
Pierard, Gérald ULg; Uhoda, Emmanuelle ULg

in Revue Médicale de Liège (2005), 60 Suppl 1

The optical properties of skin and of chromophores orientate and absorbe light. The resulting skin colour can be assessed by visual inspection or by objective methods. Spectrophotometry, tristimulus ... [more ▼]

The optical properties of skin and of chromophores orientate and absorbe light. The resulting skin colour can be assessed by visual inspection or by objective methods. Spectrophotometry, tristimulus colorimetry and computerized image analysis are well codified methods. Epidermal melanisation is detected with great sensitivity under ultraviolet light illumination. [less ▲]

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See detailPhotoprotection cutanée.
Henry, Frédérique ULg; Pierard, Claudine ULg; Pierard, Gérald ULg

in Revue Médicale de Liège (2005), 60 Suppl 1

Physical or chemical photoprotection is mandatory in order to prevent some of the negative effects of ultraviolet light exposure.

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See detailLa photoprotection en 2012
LIBON, Florence ULg; DEZFOULIAN, Bita ULg; NIKKELS, Arjen ULg

in Skin Inc (2012)

La photoprotection est essentielle dans la prévention du processus de photovieillissement et de la carcinogenèse cutanée. Elle peut être comportementale, naturelle, induite, vestimentaire, topique et ... [more ▼]

La photoprotection est essentielle dans la prévention du processus de photovieillissement et de la carcinogenèse cutanée. Elle peut être comportementale, naturelle, induite, vestimentaire, topique et systémique. La photoprotection vestimentaire inclut le port de vêtements protecteurs, de lunettes solaires et de chapeau. La photoprotection externe topique repose sur l'utilisation de différents véhicules contenant siot des filtres minéraux, ayant pour but une réflexion de la radiation ultraviolette incidente, soit des agents chimiques qui absorbent une partie de la radiation incidente. La photoprotection systémique consiste en l'administration, par voie orale, de substances photoprotectrices. D'autres nouvelles voies de photoprotection sont les stimulations chimique ou hormonale de la mélanogenèse. Cet article revoit les dernières évolutions dans ce domaine. [less ▲]

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See detailPHOTOREDUCTION OF PROTOCHLOROPHYLLIDE IN DARK-GROWN BEAN COTYLEDONS AS A FUNCTION OF AGE
SCHOEFS, B.; Bertrand, Marie-Christine ULg; Garnir, Henri-Pierre ULg et al

in Murata, N (Ed.) Research in Photosynthesis (1992)

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See detailPHOTOREDUCTION OF PROTOCHLOROPHYLLIDE TO CHLOROPHYLLIDE IN 2-D-OLD DARK-GROWN BEAN (PHASEOLUS-VULGARIS CV COMMODORE) LEAVES - COMPARISON WITH 10-D-OLD DARK-GROWN (ETIOLATED) LEAVES
SCHOEFS, B.; Franck, Fabrice ULg

in Journal of Experimental Botany (1993), 44(263), 1053-1057

Two-d-old leaves which do not contain prolamellar bodies synthesize active protochlorophyllide in darkness. When protochlorophyllide is photoreduced by one intense white flash, a main chlorophyllide ... [more ▼]

Two-d-old leaves which do not contain prolamellar bodies synthesize active protochlorophyllide in darkness. When protochlorophyllide is photoreduced by one intense white flash, a main chlorophyllide species emitting at 690 nm is formed. After the photoreduction, the emission maximum is shifted to 675 nm within 5 s. This result suggests that in young leaves, chlorophyllide formed after one flash is quickly released from the active site of NADPH: protochlorophyllide oxidoreductase. This interpretation is strenghtened by time-resolved fluorescence measurements at room temperature, showing that 675 nm emitting chlorophyllide does not transfer excitation energy to the 696 nm emitting chlorophyllide which is formed in very low amount. In 10-d-old bean leaves, the 690 nm chlorophyllide emitting species formed after one short flash undergoes the well-known rapid and Shibata spectral shifts. The 675 nm emitting chlorophyllide appears only as a shoulder. At both ages, the fluorescence intensity of the active protochlorophyllide strongly decreases during and after photoreduction, suggesting rapid modifications in the close environment of the pigment. [less ▲]

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See detailThe photorefractive effect at large modulation depth in semiconductors with multiple defect levels
Nguyen, Ngoc Duy ULg; Schmeits, Marcel ULg

in Applied Physics B : Lasers & Optics (2002), 74

The photorefractive effect in semiconducting mate- rials with multiple defects is studied in the case of modulation depth m = 1. The basic equations are Poisson's equation and the continuity equations for ... [more ▼]

The photorefractive effect in semiconducting mate- rials with multiple defects is studied in the case of modulation depth m = 1. The basic equations are Poisson's equation and the continuity equations for electrons, holes and occupied defect levels. They include all recombination and optical generation mechanisms between the defect levels and valence and conduc- tion bands. Their explicit numerical solution yields microscopic quantities such as space- and time-dependent electrical field profiles, carrier concentrations, as well as generation and re- combination rates. The fundamental Fourier component of the electric field yields the two-wave-mixing gain. Application is made for InP with two levels in the forbidden gap, for which steady-state and transient resulting quantities are shown. The re- sulting features at large modulation depth are of non-sinusoidal shape. Due to the complexity of the system, the final results strongly depend on all parameters intervening in the models used, as is illustrated for several typical cases. [less ▲]

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See detailPhotorefractive holographic interferometry for movable artwork assessment
Thizy, Cédric ULg; Georges, Marc ULg; Koulompi, Eleni et al

in Hesselink, Lambertus; Feinberg, Jack (Eds.) Controlling Light with Light: Photorefractive Effects, Photosensitivity, Fiber Gratings, Photonic Materials and More (PR07) (2007, October)

Photorefractive holographic interferometry is applied to assessment of movable cultural heritage. Its role is to observe tiny signatures resulting from internal artwork characteristics. In the future, the ... [more ▼]

Photorefractive holographic interferometry is applied to assessment of movable cultural heritage. Its role is to observe tiny signatures resulting from internal artwork characteristics. In the future, the system will be used for both antifraud and restoration [less ▲]

Detailed reference viewed: 26 (2 ULg)