Diversos corantes vitais vêm sendo estudados e utilizados para a facilitação da capsulotomia curvilínea contínua (CCC) nas cirurgias de catarata no homem e nos animais. Além de corar adequadamente a cápsula anterior da lente e favorecer um melhor desempenho do cirurgião durante a realização da CCC, os corantes vitais devem ser seguros quanto aos seus efeitos sobre as estruturas oculares, em especial ao endotélio corneano, quando empregados com esta finalidade. O azul brilhante é um corante vital já empregado em cirurgias oculares do segmento posterior para coloração da retina e atualmente estudado sobre seu potencial de utilização em cirurgias de catarata para coloração da cápsula anterior da lente. Com o objetivo de avaliar os efeitos do uso intracameral do azul brilhante 0,05% na ultra-estrutura do endotélio corneano de suínos, vinte córneas de suínos foram avaliadas divididas em dois grupos: córneas dos bulbos oculares direitos (grupo controle) e esquerdos (grupo experimental). Todos os bulbos oculares foram previamente avaliados por microscopia especular. No grupo experimental foi realizada injeção intracameral de 0,2ml do corante azul brilhante 0,05% (OPTH-blue®) que permaneceu por um minuto antes de ser removido pela aplicação de solução salina balanceada. As córneas de ambos os grupos foram excisadas e avaliadas por microscopia eletrônica de varredura. Não houve diferença entre as imagens endoteliais obtidas em ambos os grupos. O uso intracameral do azul brilhante 0,05% não causou efeitos deletérios ao endotélio corneano dos suínos e pode, portanto, ser considerado uma escolha segura para a coloração da cápsula anterior da lente para cirurgias de catarata. / Several vital dyes have been studied and used to help the continuous curvilinear capsulotomy (CCC) in cataract surgery in men and animals. Besides staining the anterior capsule of the lens properly and providing the surgeons a better performance in the CCC, the vital dyes must be safe for their effects on ocular structures, particularly the corneal endothelium when used for this purpose. The brilliant blue is a vital dye already employed in the posterior segment eye surgeries for retinal staining and currently studied about its potential use in cataract surgeries to stain the anterior capsule of the lens. In order to evaluate the effects of the use of 0.05% intra-cameral brilliant blue in the ultra-structure of the corneal endothelium of pigs, twenty swine corneas were evaluated in two groups: right eye bulb corneas (control group) and left eye bulb corneas (experimental group). All eye bulbs were previously evaluated by specular microscopy. In the experimental group, a 0.2 ml intra-cameral injection of 0.05% brilliant blue dye (blue-OPTH ®) was given, which remained for a minute before being removed by the application of balanced salt solution. The corneas of both groups were excised and evaluated by scanning electron microscopy. There was no difference between the endothelial images obtained in both groups. The use of 0.05% intra-cameral brilliant blue caused no detrimental effects to the corneal endothelium of pigs and can therefore be considered a safe choice for staining the anterior capsule of the lens for cataract surgery.

Diversos corantes vitais vêm sendo estudados e utilizados para a facilitação da capsulotomia curvilínea contínua (CCC) nas cirurgias de catarata no homem e nos animais. Além de corar adequadamente a cápsula anterior da lente e favorecer um melhor desempenho do cirurgião durante a realização da CCC, os corantes vitais devem ser seguros quanto aos seus efeitos sobre as estruturas oculares, em especial ao endotélio corneano, quando empregados com esta finalidade. O azul brilhante é um corante vital já empregado em cirurgias oculares do segmento posterior para coloração da retina e atualmente estudado sobre seu potencial de utilização em cirurgias de catarata para coloração da cápsula anterior da lente. Com o objetivo de avaliar os efeitos do uso intracameral do azul brilhante 0,05% na ultra-estrutura do endotélio corneano de suínos, vinte córneas de suínos foram avaliadas divididas em dois grupos: córneas dos bulbos oculares direitos (grupo controle) e esquerdos (grupo experimental). Todos os bulbos oculares foram previamente avaliados por microscopia especular. No grupo experimental foi realizada injeção intracameral de 0,2ml do corante azul brilhante 0,05% (OPTH-blue®) que permaneceu por um minuto antes de ser removido pela aplicação de solução salina balanceada. As córneas de ambos os grupos foram excisadas e avaliadas por microscopia eletrônica de varredura. Não houve diferença entre as imagens endoteliais obtidas em ambos os grupos. O uso intracameral do azul brilhante 0,05% não causou efeitos deletérios ao endotélio corneano dos suínos e pode, portanto, ser considerado uma escolha segura para a coloração da cápsula anterior da lente para cirurgias de catarata. / Several vital dyes have been studied and used to help the continuous curvilinear capsulotomy (CCC) in cataract surgery in men and animals. Besides staining the anterior capsule of the lens properly and providing the surgeons a better performance in the CCC, the vital dyes must be safe for their effects on ocular structures, particularly the corneal endothelium when used for this purpose. The brilliant blue is a vital dye already employed in the posterior segment eye surgeries for retinal staining and currently studied about its potential use in cataract surgeries to stain the anterior capsule of the lens. In order to evaluate the effects of the use of 0.05% intra-cameral brilliant blue in the ultra-structure of the corneal endothelium of pigs, twenty swine corneas were evaluated in two groups: right eye bulb corneas (control group) and left eye bulb corneas (experimental group). All eye bulbs were previously evaluated by specular microscopy. In the experimental group, a 0.2 ml intra-cameral injection of 0.05% brilliant blue dye (blue-OPTH ®) was given, which remained for a minute before being removed by the application of balanced salt solution. The corneas of both groups were excised and evaluated by scanning electron microscopy. There was no difference between the endothelial images obtained in both groups. The use of 0.05% intra-cameral brilliant blue caused no detrimental effects to the corneal endothelium of pigs and can therefore be considered a safe choice for staining the anterior capsule of the lens for cataract surgery.

Diversos corantes vitais vêm sendo estudados e utilizados para a facilitação da capsulotomia curvilínea contínua (CCC) nas cirurgias de catarata no homem e nos animais. Além de corar adequadamente a cápsula anterior da lente e favorecer um melhor desempenho do cirurgião durante a realização da CCC, os corantes vitais devem ser seguros quanto aos seus efeitos sobre as estruturas oculares, em especial ao endotélio corneano, quando empregados com esta finalidade. O azul brilhante é um corante vital já empregado em cirurgias oculares do segmento posterior para coloração da retina e atualmente estudado sobre seu potencial de utilização em cirurgias de catarata para coloração da cápsula anterior da lente. Com o objetivo de avaliar os efeitos do uso intracameral do azul brilhante 0,05% na ultra-estrutura do endotélio corneano de suínos, vinte córneas de suínos foram avaliadas divididas em dois grupos: córneas dos bulbos oculares direitos (grupo controle) e esquerdos (grupo experimental). Todos os bulbos oculares foram previamente avaliados por microscopia especular. No grupo experimental foi realizada injeção intracameral de 0,2ml do corante azul brilhante 0,05% (OPTH-blue®) que permaneceu por um minuto antes de ser removido pela aplicação de solução salina balanceada. As córneas de ambos os grupos foram excisadas e avaliadas por microscopia eletrônica de varredura. Não houve diferença entre as imagens endoteliais obtidas em ambos os grupos. O uso intracameral do azul brilhante 0,05% não causou efeitos deletérios ao endotélio corneano dos suínos e pode, portanto, ser considerado uma escolha segura para a coloração da cápsula anterior da lente para cirurgias de catarata. / Several vital dyes have been studied and used to help the continuous curvilinear capsulotomy (CCC) in cataract surgery in men and animals. Besides staining the anterior capsule of the lens properly and providing the surgeons a better performance in the CCC, the vital dyes must be safe for their effects on ocular structures, particularly the corneal endothelium when used for this purpose. The brilliant blue is a vital dye already employed in the posterior segment eye surgeries for retinal staining and currently studied about its potential use in cataract surgeries to stain the anterior capsule of the lens. In order to evaluate the effects of the use of 0.05% intra-cameral brilliant blue in the ultra-structure of the corneal endothelium of pigs, twenty swine corneas were evaluated in two groups: right eye bulb corneas (control group) and left eye bulb corneas (experimental group). All eye bulbs were previously evaluated by specular microscopy. In the experimental group, a 0.2 ml intra-cameral injection of 0.05% brilliant blue dye (blue-OPTH ®) was given, which remained for a minute before being removed by the application of balanced salt solution. The corneas of both groups were excised and evaluated by scanning electron microscopy. There was no difference between the endothelial images obtained in both groups. The use of 0.05% intra-cameral brilliant blue caused no detrimental effects to the corneal endothelium of pigs and can therefore be considered a safe choice for staining the anterior capsule of the lens for cataract surgery.

Ultrashort, nearly monochromatic hard X-ray pulses enrich the understanding of the dynamics and function of matter, e.g., the motion of atomic structures associated with ultrafast phase transitions, structural dynamics and (bio)chemical reactions. Inverse Compton backscattering of intense laser pulses from relativistic electrons not only allows for the generation of bright X-ray pulses which can be used in a pump-probe experiment, but also for the investigation of the electron beam dynamics at the interaction point. The focus of this PhD work lies on the detailed understanding of the kinematics during the interaction of the relativistic electron bunch and the laser pulse in order to quantify the influence of various experiment parameters on the emitted X-ray radiation. The experiment was conducted at the ELBE center for high power radiation sources using the ELBE superconducting linear accelerator and the DRACO Ti:sapphire laser system. The combination of both these state-of-the-art apparatuses guaranteed the control and stability of the interacting beam parameters throughout the measurement. The emitted X-ray spectra were detected with a pixelated detector of 1024 by 256 elements (each 26μm by 26μm) to achieve an unprecedented spatial and energy resolution for a full characterization of the emitted spectrum to reveal parameter influences and correlations of both interacting beams. In this work the influence of the electron beam energy, electron beam emittance, the laser bandwidth and the energy-angle-correlation on the spectra of the backscattered X-rays is quantified. A rigorous statistical analysis comparing experimental data to ab-initio 3D simulations enabled, e.g., the extraction of the angular distribution of electrons with 1.5% accuracy and, in total, provides predictive capability for the future high brightness hard X-ray source PHOENIX (Photon electron collider for Narrow bandwidth Intense X-rays) and potential all optical gamma-ray sources. The results will serve as a milestone and starting point for the scaling of the X-ray flux based on available interaction parameters of an ultrashort bright X-ray source at the ELBE center for high power radiation sources. The knowledge of the spatial and spectral distribution of photons from an inverse Compton scattering source is essential in designing future experiments as well as for tailoring the X-ray spectral properties to an experimental need. / Ultrakurze, quasi-monochromatische harte Röntgenpulse erweitern das Verständnis für die dynamischen Prozesse und funktionalen Zusammenhänge in Materie, beispielsweise die Dynamik in atomaren Strukturen bei ultraschnellen Phasenübergängen, Gitterbewegungen und (bio)chemischen Reaktionen. Compton-Rückstreuung erlaubt die Erzeugung der für ein pump-probe-Experiment benötigten intensiven Röntgenpulse und ermöglicht gleichzeitig einen Einblick in die komplexen kinematischen Prozesse während der Wechselwirkung von Elektronen und Photonen. Ziel dieser Arbeit ist, ein quantitatives Verständnis der verschiedenen experimentellen Einflüsse auf die emittierte Röntgenstrahlung bei der Streuung von Laserphotonen an relativistischen Elektronen zu entwickeln. Die Experimente wurden am ELBE - Zentrum für Hochleistungs-Strahlenquellen des Helmholtz-Zentrums Dresden - Rossendorf durchgeführt. Der verwendete supraleitende Linearbschleuniger ELBE und der auf Titan-Saphir basierende Hochleistungslaser DRACO garantieren ein Höchstmaß an Kontrolle und Stabilität der experimentellen Bedingungen. Zur Messung der emittierten Röntgenstrahlung wurde ein Siliziumdetektor mit 1024x256 Pixeln (Pixelgröße 26μm × 26μm) verwendet, welcher für eine bisher nicht erreichte spektrale und räumliche Auflösung sorgt. Die so erfolgte vollständige Charakterisierung der Energie-Winkel-Beziehung erlaubt Rückschlüsse auf Parametereinflüsse und Korrelationen von Elektronen- und Laserstrahl. Eine umfassende statistische Analyse, bei der ab-initio 3D Simulationen mit den experimentellen Daten verglichen und ausgewertet wurden, ermöglichte u.a. die Bestimmung der Elektronenstrahldivergenz mit einer Genauigkeit von 1.5% und erlaubt Vorhersagen zur zu erwartenden Strahlung der zukünftigen brillianten Röntgenquelle PHOENIX (Photon electron collider for Narrow bandwidth Intense X-rays) und potentiellen lasergetriebenen Gammastrahlungsquellen. Die Ergebnisse dienen als Fixpunkt für die Skalierung des erwarteten Photonenflusses der Röntgenquelle für die verfügbaren Ausgangsgrößen am Helmholtz-Zentrum Dresden - Rossendorf. Das Wissen um die räumliche und spektrale Verteilung der Röntgenstrahlung ist entscheidend für die Planung zukünftiger Experimente sowie zur Anpassung der Quelle an experimentelle Bedürfnisse.

Ultrashort, nearly monochromatic hard X-ray pulses enrich the understanding of the dynamics and function of matter, e.g., the motion of atomic structures associated with ultrafast phase transitions, structural dynamics and (bio)chemical reactions. Inverse Compton backscattering of intense laser pulses from relativistic electrons not only allows for the generation of bright X-ray pulses which can be used in a pumpprobe experiment, but also for the investigation of the electron beam dynamics at the interaction point. The focus of this PhD work lies on the detailed understanding of the kinematics during the interaction of the relativistic electron bunch and the laser pulse in order to quantify the influence of various experiment parameters on the emitted X-ray radiation. The experiment was conducted at the ELBE center for high power radiation sources using the ELBE superconducting linear accelerator and the DRACO Ti:sapphire laser system. The combination of both these state-of-the-art apparatuses guaranteed the control and stability of the interacting beam parameters throughout the measurement. The emitted X-ray spectra were detected with a pixelated detector of 1024 by 256 elements (each 26μm by 26μm) to achieve an unprecedented spatial and energy resolution for a full characterization of the emitted spectrum to reveal parameter influences and correlations of both interacting beams. In this work the influence of the electron beam energy, electron beam emittance, the laser bandwidth and the energy-anglecorrelation on the spectra of the backscattered X-rays is quantified. A rigorous statistical analysis comparing experimental data to ab-initio 3D simulations enabled, e.g., the extraction of the angular distribution of electrons with 1.5% accuracy and, in total, provides predictive capability for the future high brightness hard X-ray source PHOENIX (Photon electron collider for Narrow bandwidth Intense X-rays) and potential all optical gamma-ray sources. The results will serve as a milestone and starting point for the scaling of the Xray flux based on available interaction parameters of an ultrashort bright X-ray source at the ELBE center for high power radiation sources. The knowledge of the spatial and spectral distribution of photons from an inverse Compton scattering source is essential in designing future experiments as well as for tailoring the X-ray spectral properties to an experimental need. / Ultrakurze, quasi-monochromatische harte Röntgenpulse erweitern das Verständnis für die dynamischen Prozesse und funktionalen Zusammenhänge in Materie, beispielsweise die Dynamik in atomaren Strukturen bei ultraschnellen Phasenübergängen, Gitterbewegungen und (bio)chemischen Reaktionen. Compton-Rückstreuung erlaubt die Erzeugung der für ein pump-probe-Experiment benötigten intensiven Röntgenpulse und ermöglicht gleichzeitig einen Einblick in die komplexen kinematischen Prozesse während der Wechselwirkung von Elektronen und Photonen. Ziel dieser Arbeit ist, ein quantitatives Verständnis der verschiedenen experimentellen Einflüsse auf die emittierte Röntgenstrahlung bei der Streuung von Laserphotonen an relativistischen Elektronen zu entwickeln. Die Experimente wurden am ELBE - Zentrum für Hochleistungs-Strahlenquellen des Helmholtz-Zentrums Dresden - Rossendorf durchgeführt. Der verwendete supraleitende Linearbschleuniger ELBE und der auf Titan-Saphir basierende Hochleistungslaser DRACO garantieren ein Höchstmaß an Kontrolle und Stabilität der experimentellen Bedingungen. Zur Messung der emittierten Röntgenstrahlung wurde ein Siliziumdetektor mit 1024x256 Pixeln (Pixelgröße 26μm × 26μm) verwendet, welcher für eine bisher nicht erreichte spektrale und räumliche Auflösung sorgt. Die so erfolgte vollständige Charakterisierung der Energie-Winkel-Beziehung erlaubt Rückschlüsse auf Parametereinflüsse und Korrelationen von Elektronen- und Laserstrahl. Eine umfassende statistische Analyse, bei der ab-initio 3D Simulationen mit den experimentellen Daten verglichen und ausgewertet wurden, ermöglichte u.a. die Bestimmung der Elektronenstrahldivergenz mit einer Genauigkeit von 1.5% und erlaubt Vorhersagen zur zu erwartenden Strahlung der zukünftigen brillianten Röntgenquelle PHOENIX (Photon electron collider for Narrow bandwidth Intense X-rays) und potentiellen lasergetriebenen Gammastrahlungsquellen. Die Ergebnisse dienen als Fixpunkt für die Skalierung des erwarteten Photonenflusses der Röntgenquelle für die verfügbaren Ausgangsgrößen am Helmholtz-Zentrum Dresden - Rossendorf. Das Wissen um die räumliche und spektrale Verteilung der Röntgenstrahlung ist entscheidend für die Planung zukünftiger Experimente sowie zur Anpassung der Quelle an experimentelle Bedürfnisse.

M.A. / This study approaches a special area of comparative literature in English which has not been researched in any great detail to date. Olive Schreiner's The Story of an African Farm, first published in 1883, had an Australian counterpart in Miles Franklin's My Brilliant Career, first published in 1901. Both novels stemmed from a deep-rooted discontent with Colonial society and, specifically, with the status of women in that society. Both these novelists were early Colonial writers whose works proved to be watersheds in the development of the literary output of their respective countries. Both novelists have a similar status in their respective literature, and their novels show many comparable attributes ...

Treatment of textile wastewaters containing dye materials using the conventional methods based on biological treatment is not possible. In order to overcome this problem, ozonation based on the oxidation of organic pollutants with ozone gas dissolved in aqueous phase have been studied widely. Catalytic ozonation and advanced oxidation processes (AOP) are also used in order to increase the efficiency of sole ozonation In this work, catalytic ozonation processes in the presence of Copper Sulfide (CuS) powder and a synthesized catalyst by the impregnation of iron on alumina (Fe/Al2O3) were studied separately in the treatment of dye solutions, namely Remazol Brilliant Blue-R (RBBR) and Reactive Black-5 (RB-5). Besides catalytic ozonation runs, ozonation parameters and ozonation mechanism were also studied and a model was developed for the semi-batch ozonation. Both catalysts increased the oxidation of side products measured by the decrease in the amount of total organic carbon (TOC) in the treated dye solutions. Dye removal rates were also enhanced in the treatment of RB-5 dye solutions while no significant effect was observed on dye removal rates of RBBR solutions. TOC removals above 90% were observed in the catalytic ozonation using CuS for both of the dye solutions at pH =10 having initial dye concentration of 100 mg/L. The most significant effect of the catalyst addition was observed at pH = 3 where the TOC removals of non-catalytic ozonation were the lowest. CuS addition increased percent TOC removal at the end of the reaction period of 80 min by 123% in the treatment of 100 mg/L RBBR solution, and by 65% in the treatment of 100 mg/L RB-5 solution at pH = 3. On the other hand, addition of Fe/Al2O3 catalyst increased TOC removal of 100 mg/L RB-5 solution by 52 % at pH = 3. In addition, volumetric mass transfer coefficients (kLa) of ozone in the absence and in the presence of a chemical reaction between dye and ozone were estimated from modeling. A correlation for the enhancement factor of ozone absorbed into dye solutions in terms of initial dye concentration was obtained and reported.

In this study, silver nanorods and nanospheroids were prepared both in aqueous solution and on the surface of glass slides through seed-mediated growth approach at room temperature and used as a surface enhanced Raman scattering (SERS) substrate. The synthesis of metallic nanorods was started with the production of silver nanospheres as seed utilizing sodium borohydride and trisodium citrate as reducing and capping agents, respectively. These seeds were then added to a growth solution containing additional silver salt, ascorbic acid and cetyltrimethylammonium bromide (CTAB.) Nanorod preparation conditions were first optimized in solution phase. The plasmon absorption of the formed nanocrystals was monitored by UV-Visible spectrometry. The largest red shift in the longitudinal plasmon resonance absorption of silver nanostructures was tried to be achieved in order to realize the highest electromagnetic enhancement in Raman measurements. The images of the formed nanorods were recorded using field emission scanning electron microscopy (FE-SEM). The optimized colloidal growth conditions were adopted for the growth of nanorods on the surface of the glass substrate. Sol-gel coated glass slides were used in order to increase the porosity on the surface for an effective seeding process. We reported the development of a novel SERS substrate prepared by growing silver nanorods directly on the surface of glass surface without using any linker molecule. The SERS performances of the nanorod growth surfaces were evaluated with crystal violet (CV), brilliant cresyl blue (BCB) and benzoic acid (BA). Some modifications such as the increase in the AgNO3 concentration in the growth solution and the addition of hydrocarbons to the growth solution were investigated for the enhancement of the SERS signal. The intense spectra obtained for the model compounds demonstrated the efficiency of the prepared substrate for the SERS enhancement and its potential as a SERS detection probe for chemical and biological analysis.

The purpose of this study was to investigate the ultrastructure of the membrana limitans interna (internal limiting membrane, ILM) and to evaluate alterations to the retinal cell layers after membrane peeling with vital dyes. Twenty-five patients (25 eyes) who underwent macular hole surgery were included, whereby 12 indocyanine green (ICG)- and 13 brilliant blue G (BBG)-stained ILM were analyzed using light, transmission electron and scanning electron microscopy. Retinal cell fragments on the ILM were identified in both groups using immunohistochemistry. Comparing ICG- and BBG-stained membranes, larger cellular fragments were observed at a higher frequency in the BBG group. Thereby, the findings indicate that ICG permits an enhanced separation of the ILM from the underlying retina with less mechanical destruction. A possible explanation might be seen in the known photosensitivity of ICG, which induces a stiffening and shrinkage of the ILM but also generates retinal toxic metabolites

Un dispositif expérimental a été développé pour l'étude du couplage de la croissance d'un biofilm de Shewanella oneidensis MR-1 et du transport conservatif de l'Erioglaucine. La croissance du biofilm a été suivie par mesure de conductivité hydraulique et par acquisition d'images à l'aide d'une caméra digitale. La fraction volumique du biofilm a été caractérisée par des essais d'élution d'une macromolécule (i.e. : le Bleu Dextran) par analogie avec les méthodes de chromatographie d'exclusion ou de filtration sur gel. Ainsi au bout de 29 jours, un biofilm quasi-homogène sur l'ensemble de la cellule d'écoulement (0,1×0,1×0,05m3) et équivalent à 50% du volume poral a été formé. L'influence de la croissance du biofilm sur les propriétés de transport du milieu a été évaluée. Les essais de transport conservatif de l'Erioglaucine effectués pour deux vitesses d'injection et à deux stades de croissance du biofilm (17 et 29 jours) ont montré l'influence d'hétérogénéités locales sur les paramètres de transport (i.e. : la porosité, la perméabilité et la dispersion hydrodynamique). Ainsi après 17 jours de culture quand le biofilm occupe partiellement le milieu poreux (moitié inférieure) un modèle à deux équations ou double milieu permet de caractériser le transport conservatif. A contrario après 29 jours de culture où le biofilm occupe tout le milieu poreux, un comportement fickien classique caractérise le transport. Les valeurs théoriques du coefficient de dispersion longitudinale prédites par la méthode de prise de moyenne volumique ont permis de reproduire de manière satisfaisante le comportement observé expérimentalement / An experimental device was performed for the study of coupling the growth of a Shewanella oneidensis MR-1 bacterial biofilm and the non reactive transport of Brilliant Blue FCF. The biofilm growth was monitored by hydraulic conductivity measurements and by image acquisition with a digital camera. The biofilm volume fraction was estimated through tracer experiments with a macromolecular tracer (i.e., Dextran Blue) as in size-exclusion chromatography or gel filtration chromatography. Then after 29 days of bacterial culture a quasi-homogenous biofilm was grown in the whole flow cell (0,1×0,1×0,05m3) occupying about 50% of void space volume. The influence of biofilm growth on porous media transport properties was evaluated. Conservative tracer experiments with Brilliant Blue FCF run at two hydrodynamic conditions and at two growth steps of biofilm (17 and 29 days) showed the influence of local heterogeneities on transport parameters (i.e., porosity, permeability and hydrodynamic dispersion). Then at 17 days of growth when the biofilm partially covers the porous medium (bottom half of the flow cell) a two-equation model or double-layer model was suitable to characterize the conservative transport. A contrario after 29 days of growth, when the biofilm covers the whole porous medium, a classical fickian model was convenient. Numerical values of longitudinal dispersion coefficient from volume averaging well fitted experimental results