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ETUDE D’ADSORPTION DE VIOLET DE GENTIANE SUR LA SCIURE DE BOIS

ETUDE D’ADSORPTION DE VIOLET DE GENTIANE SUR LA SCIURE DE BOIS

E) La Cinétique d’adsorption du colorant Violet de gentiane Pour estimer le temps d’équilibre de l’interaction entre le colorant VG et l’adsorbant, la sciure de bois, nous avons procédé comme suit : une masse de 1 g d’adsorbant est mise en contact avec 200 ml d’une solution de colorant à 20 mg/L. Les expériences d’adsorption ont été suivies pendant plus de 180 minutes. Une vitesse d’agitation de 150 tours/min a été choisie pour toutes les expériences. Pour déterminer la quantité de colorant retenue en fonction du temps, on a dosé par spectrophotométrie visible la solution après l’interaction avec l’adsorbant. Pour ce fait, le mélange adsorbant/solution de colorant est centrifugé à 3000 tr/min pendant 10 minutes. Le surnageant est récupéré et son absorbance est mesurée à la longueur d’onde d’absorption maximale.
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Etude d’élimination de violet de gentiane par les noyaux de datte a l’état brut et traités par une solution alcaline

Etude d’élimination de violet de gentiane par les noyaux de datte a l’état brut et traités par une solution alcaline

 Chapitre II: Dans ce chapitre nous avons donné quelques généralités sur l’adsorption pour mieux définir l’importance de ce processus, il aborde principalement les types d’adsorption [r]

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DEGRADATION D’UN COLORANT LE GENTIANE VIOLET PAR LA TECHNIQUE DE L’ELECTROCOAGULATION

DEGRADATION D’UN COLORANT LE GENTIANE VIOLET PAR LA TECHNIQUE DE L’ELECTROCOAGULATION

[Ala, 2009]. Figure I.12 : Structure chimique du colorant triphénylméthane "Gentian Violet" [Ala, 2009]. Le Violet de Gentiane fait partie des Violets de méthyle, qui constituent un groupe de colorants basiques. C’est un mélange de chlorhydrates de violets 5- et 6-méthylés. (pentaméthylpa-rarosaniline et violet hexaméthylé, appelé Cristal violet [Lecomte]. C’une molécule complètement symétrique dans laquelle chaque groupe amino contient 2 groupes méthyle.19 Étant donné que le GV est un trimère de diméthylaniline stabilisé par résonance pour donner un composé très coloré, il y a six groupes méthyles [Maley et al, 2013].
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Evidence for excess argon during high pressure metamorphism in the Dora Maira Massif (Western Alps, Italy), using an ultra-violet laser ablation microprobe (super 40) Ar- (super 39) Ar technique

Evidence for excess argon during high pressure metamorphism in the Dora Maira Massif (Western Alps, Italy), using an ultra-violet laser ablation microprobe (super 40) Ar- (super 39) Ar technique

11 Conclusions. In the Brossasco metagranite, minerals hthat suffered the HP conditions or hwhich recrystallized during the amphibolite grade retrogression show ages ranging from 40 Ma to 614 Ma, in a granite with U-Pb age of ca. 300 Ma. Excess argon with varying isotopic ratios has been measured using a new high resolution ultra-violet laser ablation microprobe, in phengite, biotite, quartz and K-feldspar. Though the existence of the eo-alpine HP event in the Western Alps cannot be dismissed by our data, old 40 Ar- 39 Ar ages may be reconciled with recent Sm/Nd and U/Pb ages which suggest that the peak metamorphism is 40-45 Ma old. The old argon ages are the result of artefacts caused by incorporation of variable excess argon, with 40 Ar/ 36 Ar ratios up to 10000, followed, during retrogression, either by redistribution of that excess or incorporation of a lower 40 Ar/ 36 Ar component.
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Brain responses to violet, blue, and green monochromatic light exposures in humans: prominent role of blue light and the brainstem

Brain responses to violet, blue, and green monochromatic light exposures in humans: prominent role of blue light and the brainstem

1 Cyclotron Research Centre, University of Lie`ge, Lie`ge, Belgium, 2 Hololab, Department of Physics, University of Lie`ge, Lie`ge, Belgium, 3 Department of Neurology, Centre Hospitalier Universitaire de Lie`ge (CHU), Lie`ge, Belgium, 4 Surrey Sleep Research Centre, University of Surrey, Guildford, United Kingdom Background. Relatively long duration retinal light exposure elicits nonvisual responses in humans, including modulation of alertness and cognition. These responses are thought to be mediated in part by melanopsin-expressing retinal ganglion cells which are more sensitive to blue light than violet or green light. The contribution of the melanopsin system and the brain mechanisms involved in the establishment of such responses to light remain to be established. Methodology/Principal Findings. We exposed 15 participants to short duration (50 s) monochromatic violet (430 nm), blue (473 nm), and green (527 nm) light exposures of equal photon flux (10 13 ph/cm 2 /s) while they were performing a working memory task in fMRI. At light onset, blue light, as compared to green light, increased activity in the left hippocampus, left thalamus, and right amygdala. During the task, blue light, as compared to violet light, increased activity in the left middle frontal gyrus, left thalamus and a bilateral area of the brainstem consistent with activation of the locus coeruleus. Conclusion/Significance. These results support a prominent contribution of melanopsin-expressing retinal ganglion cells to brain responses to light within the very first seconds of an exposure. The results also demonstrate the implication of the brainstem in mediating these responses in humans and speak for a broad involvement of light in the regulation of brain function.
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Electrocoagulation process applied on pollutants treatment- experimental optimization and fundamental investigation of the crystal violet dye removal

Electrocoagulation process applied on pollutants treatment- experimental optimization and fundamental investigation of the crystal violet dye removal

to the repository administrator: tech-oatao@listes-diff.inp-toulouse.fr This is an author’s version published in: http://oatao.univ-toulouse.fr/20493 To cite this version: Mbacké, Maryam Khadim and Kane, Cheikhou and Diallo, Ndeye Oury and Diop, Codou Mar and Chauvet, Fabien and Comtat, Maurice and Tzedakis, Théo Electrocoagulation process applied on pollutants treatment- experimental optimization and fundamental investigation of the crystal violet dye removal. (2016) Journal of Environmental Chemical Engineering, 4 (4). 4001-4011. ISSN 2213-3437

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THE APSIS EXPERIMENT: SIMULATING TITAN'S UPPER ATMOSPHERE AND ITS PHOTOCHEMISTRY IN THE VACUUM ULTRA-VIOLET (VUV)

THE APSIS EXPERIMENT: SIMULATING TITAN'S UPPER ATMOSPHERE AND ITS PHOTOCHEMISTRY IN THE VACUUM ULTRA-VIOLET (VUV)

S. TIGRINE 1,2,* , N. CARRASCO 1 , L. VETTIER 1 , L. NAHON 2 1 LATMOS, Université Versailles St. Quentin, UPMC Univ. Paris 06, CNRS, 11 Bvd. d’Alembert, 78280 Guyancourt, France, ² Synchrotron SOLEIL, l’Orme des Merisiers, St Aubin, BP 48, 91192 Gif sur Yvette Cedex, France (*sarah.tigrine@latmos.ipsl.fr) THE APSIS EXPERIMENT: SIMULATING TITAN'S UPPER ATMOSPHERE AND ITS PHOTOCHEMISTRY IN THE VACUUM ULTRA-VIOLET (VUV)

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Vapor phase surface functionalization under ultra violet activation of parylene thin films grown by chemical vapor deposition

Vapor phase surface functionalization under ultra violet activation of parylene thin films grown by chemical vapor deposition

Previous works have been reported on the surface functionalization of parylene. The wet route was explored for parylene N or C surfaces with or without ultra violet (UV) activation. For instance, the UV/ acrylamide [6] and UV/2-methacryloyloxyethyl phosphorylcholine – benzophenone treatments [7] permitted to divide by about 2 the water contact angle of the modi fied surfaces. The state of the art on the wet treatments without UV activation gave, under the best conditions, a final contact angle of 10° compared to initial contact angles of 75 –95° [8,9] . The dry treatments using for instance reactive vapor phases without plasma activation are particularly interesting for parylene thin films because they can be applied directly in a CVD reactor or in sequence with the CVD process in a related reactor. This is a clean multi-step process particularly convenient to control the surface properties of the parylene films. Two examples are H 2 O vapor activation by a hot W
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The effect of ultra-violet irradiation on the hydroxide absorption band in potassium bromide crystals at room temperature

The effect of ultra-violet irradiation on the hydroxide absorption band in potassium bromide crystals at room temperature

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at The effect of ultra-violet irradiation on the hydroxide absorption band in potassium bromide crystals at room temperature Pearse, H.A.; Rolfe, J.

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AlN film thickness effect on photoluminescence properties of AlN/carbon nanotubes shell/core nanostructures for deep ultra-violet optoelectronic devices

AlN film thickness effect on photoluminescence properties of AlN/carbon nanotubes shell/core nanostructures for deep ultra-violet optoelectronic devices

AlN films of different thickness values were deposited via DC reactive magnetron sputtering over vertically aligned multiwalled carbon nanotube (CNTs) arrays to obtain AlN/[r]

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A Time-Evolving 3D Method Dedicated to the Reconstruction of Solar plumes and Results Using Extreme Ultra-Violet Data

A Time-Evolving 3D Method Dedicated to the Reconstruction of Solar plumes and Results Using Extreme Ultra-Violet Data

Thanks to this model we an perform time-evolving three-dimensional tomography of the solar orona using only extreme ultra-violet images. Furthermore, there is no omplex, underlying physi al model. The only assumptions are the smoothness of the solution, the area-dependant evolution model, and the knowledge of the plume position. These assumptions allow us to onsider a temporal variation of a few days, while assuming only temporal smoothness would limit variations to the order of one solar rotation (about 27 days). T o our knowledge, the estimation of the temporal evolution has never been undertaken in tomographi re onstru tion of the solar orona.
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Nitride nanophotonics from the deep ultra-violet to the near infrared: non-linear optics and microlasers

Nitride nanophotonics from the deep ultra-violet to the near infrared: non-linear optics and microlasers

Nitride semiconductors (GaN and nitride alloys) provide a spectrally-broad transparency -expanding from the near-infrared to the ultraviolet- as well as robust excitons that [r]

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Carbon dioxide plasma treated PVDF electrospun membrane for the removal of crystal violet dyes and iron oxide nanoparticles from water

Carbon dioxide plasma treated PVDF electrospun membrane for the removal of crystal violet dyes and iron oxide nanoparticles from water

case of the plasma treated PVDF membrane showed 3.84 mg/g of the membrane. Plasma treated PVDF membrane showed two- or three-times CV adsorption capacity than neat PVDF membrane which was due to the strong electrostatic interaction between the protonated CV molecules and highly negative carboxyl groups on the surface of plasma treated PVDF membrane. The fabricated membrane had good rejection rate against Fe 2 O 3 nanoparticles which implies that most of the nanoparticles were entrapped on the surface of the electrospun membrane due to its 3D in- terconnected network pore structure which was confirmed from the SEM images. Morphology studies revealed that, after plasma treatment the surface of the PVDF electrospun membrane become more smoother compared to neat PVDF membrane. The decre- ment in the contact angle of the PVDF electrospun membrane after the plasma treatment will be reduced the fouling prob- lem of the membrane to some extent. Both pristine and plasma treated PVDF membrane showed excellent filtration performance against Fe 2 O 3 nanoparticles. The demonstrated plasma treated PVDF electrospun membrane could successfully eliminate the crystal violet dyes and Fe 2 O 3 nanoparticles via adsorption and size exclusion mechanism respectively. So, we strongly considered that the present study will be an impressive platform to design the PVDF microfiltration membranes for the removal of water pollutants via adsorption and size exclusion mechanism in the near future.
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SEM study of black, blue, violet and yellow inglaze colours of the oldest Swiss tin‐opacified stove tiles (c .1450– c .1512, canton Bern)*

SEM study of black, blue, violet and yellow inglaze colours of the oldest Swiss tin‐opacified stove tiles (c .1450– c .1512, canton Bern)*

CONCLUSIONS The studied samples pertained to the first inglaze ceramic colours realised on tin-glazed stove tiles from Switzerland. The blue, yellow, violet and black colours were silica- and Pb-rich glasses, opaci fied by submillimetre crystallites suspended in the glass matrix. The colouring was caused by (1) ions dissolved in the matrix, (2) crystalline inclusions or (3) a combination of both. The analyses showed that the Bernese potters used two types of ceramic paints, produced following two major techniques. The almost cassiterite-free first type included: (1) a Co blue I with relic ‘safre’ Fe-Co-Ni spinels; (2) a yellow full of Pb-Sb-Sn particles; and (3) a black I ob- tained by admixing a small amount of MnO to the blue I. The detection of a Pb-Sn-Sb yellow pigment is a signi ficant addition to previously reported occurrences of this rare ceramic pigment in the studied time span. The second ceramic paint type was achieved by adding Fe-Co-Ni- (resulting in blue II), Mn- (violet) or Cu- (black II) rich glass powders to already pre- pared tin-opaci fied white glaze powders. As the very low K content of the blue matrix glass showed, the blue (and black I) colour could not have been produced according to the traditional smalt recipe. In this different recipe, a Pb flux was used. Due to the CaO content, at least two tin glaze recipes could be distinguished. The colour palette of these mid-15th –early 16th centuries
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Bimodal spectroscopic evaluation of ultra violet-irradiated mouse skin inflammatory and precancerous stages: instrumentation, spectral feature extraction/selection and classification (k-NN, LDA and SVM)

Bimodal spectroscopic evaluation of ultra violet-irradiated mouse skin inflammatory and precancerous stages: instrumentation, spectral feature extraction/selection and classification (k-NN, LDA and SVM)

Because outdoor activities and esthetic considerations (such as skin tanning) are of growing interest in west- ern countries, fair-skinned populations have been more and more exposed to sun light in the past decades. Since solar ultra-violet (UV) radiation is the main environmen- tal cause of skin cancer, the incidence of the three ma- jor forms of skin cancer (melanoma, squamous cell carci- noma (SCC) and basal cell carcinoma) is growing. Even though most deaths are attributable to melanoma, SCC is the most common life-threatening cancer type [1]. In dermatology, diagnosis is based on direct visualisation of the lesion. Because such observation depends on per- sonal experience of the physician, lesions may be falsely considered benign, may not undergo biopsy, and there- fore may not be subjected to the reference diagnostic gold
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III-Nitride-on-silicon microdisk lasers from the blue to the deep ultra-violet

III-Nitride-on-silicon microdisk lasers from the blue to the deep ultra-violet

Following our recent demonstration of an optically pumped microdisk laser operating at room temperature in the UV-C spectral range, at k ¼ 275 nm, 17 we report in the present letter the declination of a whole series of microdisk lasers based on GaN/AlN and InGaN/GaN quantum wells, whose emission can be tuned from 275 nm to 470 nm. The deep-UV emission is obtained with ultra-thin binary GaN/AlN quantum wells that are presently investigated as interesting alternatives to AlGaN/AlN heterostructures. 18 All the microlasers rely on the same nitride-on-silicon platform: the quantum wells are integrated on top of a buffer layer grown on silicon that can be released into a membrane by the selective under-etching of the silicon substrate. The good radiative efficiency of the MBE (molecular beam epitaxy)-grown quantum wells results from the careful control of the crystalline quality of the very thin underlying AlN buffer layer deposited on the Si substrate. The microlasers operate under pulsed optical excitation, and the lasing threshold is reduced by a factor 10 from deep-UV GaN/AlN microdisks to the violet InGaN/GaN ones. We dem- onstrate here the broad spectral tunability of this nitride-on- silicon platform (200 nm, i.e., almost an octave) that allows foreseeing a variety of integrated photonics applications, including the multi-color integrated laser sources. All micro- disks present Q factors exceeding 1000, for a broad range of geometrical parameters, so that we are able to compare the gain thresholds of the different active layers.
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Electrocoagulation process applied on pollutants treatment- experimental optimization and fundamental investigation of the crystal violet dye removal

Electrocoagulation process applied on pollutants treatment- experimental optimization and fundamental investigation of the crystal violet dye removal

Mbacké, Maryam Khadim and Kane, Cheikhou and Diallo, Ndeye Oury and Diop, Codou Mar and Chauvet, Fabien and Comtat, Maurice and Tzedakis, Théo Electrocoagulation. process applied on [r]

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Observing the Forest Canopy with a New Ultra-Violet Compact Airborne Lidar

Observing the Forest Canopy with a New Ultra-Violet Compact Airborne Lidar

We propose using the compact ultra-violet airborne LAUVAC lidar (Lidar Aéroporté Ultra-Violet pour l’Atmosphère et la Canopée forestière, see Figure 1(a)) that has been designed as a multi-purpose system for research activities with high flexibility in terms of instrumental parameters (telescope field of view, laser divergence and emitted energy). It was developed by the Commissariat à l’Énergie Atomique (CEA) and the Centre National de la Recherche Scientifique (CNRS) to be used for atmospheric pollution [12,13] and climate studies [14]. Recently, it was adapted for airborne operation by CEA with the support of Centre National d’Etudes Spatiales (CNES) to study a Maritime pine (Pinus pinaster) forest in the Landes region (France, Figure 1(c)) in the framework of a program initiated by the Institut Pierre Simon Laplace (IPSL) and the Centre National du Machinisme Agricole, du Génie Rural, des Eaux et Forêts (CEMAGREF).
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Amélioration des taux de multiplication chez deux clones d’artichaut (Cynara Scolymus L.) Le violet d’Alger et le violet hyérois.

Amélioration des taux de multiplication chez deux clones d’artichaut (Cynara Scolymus L.) Le violet d’Alger et le violet hyérois.

Notre essai qui a consisté en une suppression des tiges florales juste après la fin du stade végétatif et le début de la phase florale c'est-à-dire l’initiation des capitules aines (premiers capitules) favorisant ainsi l’initiation des rejets (cabosses et œilletons) à la base des racines et du collet. Les résultats obtenus sont intéressants puisque le niveau de production est passé de trois cabosses par plant pour le témoin à treize cabosses par plant pour les plants traites (suppression des tiges) pour le violet hyérois. Cela signifierait que pour chaque hectare de champs de pieds mère pourra engendrer treize hectares de plants sains produits localement. S’agissant du violet d’alger, son taux de deuse n’a pas évolué mais cela n’est pas problématique dans la mesure où ce clone est très disponible.
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Elimination Du Cristal Violet Par Un Charbon Actif Granulé

Elimination Du Cristal Violet Par Un Charbon Actif Granulé

Ces résultats montrent que l’équilibre est atteint assez rapidement, un temps supposé amplement suffisant pour atteindre l’équilibre est de 90minpour cristal violet. IV.5. Effet de la dose de l’adsorbant sur l’adsorption Parmi les facteurs influençant les propriétés de l’adsorption, la dose du charbon actif parce qu’elle détermine le degré de l’adsorption et peut être utilisée pour prédire le coût du charbon actif par unité de solution traitée. Un volume de 25mL de solution et de concentration connue a été mélangé et agité avec des doses d’adsorbant comprises entre 2 et 16 g/L pendant un temps déterminé préalablement(90min) pour Cristal violet. Pour confirmer l’effet de la dose, on a étudié deux concentrations dont les résultats obtenus pour la première concentration et pour la deuxième concentration représentés sont regroupés dans le tableau IV.7 représentés graphiquement sur la figureIV.13
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