[pt] Neste trabalho, apresenta-se um estudo dos processos de transporte e biodegradação do benzeno e da mistura benzeno/etanol em um solo contaminado, através de simulações em diferentes modelos. Nas simulações foi utilizado o programa de elementos finitos FEFLOW 6.1, para análise de fluxo e transporte de contaminantes. No estudo incorporou-se satisfatoriamente o modelo de reação cinético de Monod multiplicativo, para problemas de transporte de contaminantes, no módulo de reação definido pelo usuário (FEMATHED) do programa FEFLOW 6.1. Este modelo foi utilizado nas diversas simulações realizadas. Para encontrar os valores de parâmetros de Monod e da população bacteriana, simulou-se o comportamento de um bloco de solo in situ contaminado com benzeno usando dados experimentais publicado na dissertação de mestrado de Martins (2010). Como aplicação dos procedimentos estudados, foram simuladas duas colunas em PVC com amostras indeformadas de um solo residual (lisímetros), onde foi fornecida uma solução contaminante na direção vertical, contrário à gravidade, com a finalidade de avaliar ao longo da coluna, a biodegradação dos compostos de benzeno e a influência do etanol nesse processo. Além disso, avaliou-se o atraso da degradação do benzeno por causa da presença do etanol na zona saturada e pelo aumento de biomassa nos domínios simulados. O trabalho também mostra uma descrição do programa utilizado e sua formulação. Finalmente, apresenta-se, comentam-se os resultados e concluem-se a pesquisa. / [en] In this work was studied the transport and biodegradation processes of benzene and of the benzene/ethanol mixture in a contaminated soil using different simulation models. In the simulations, were used the finite element program called FEFLOW 6.1 for flow analysis and transport of contaminants. The study successfully incorporated the kinetic reaction model of multiplicative Monod, for contaminant transport problems, in a reaction module defined by the user (FEMATHED - FEFLOW 6.1). This model was applied in the simulations. To find the values of Monod parameters and bacterial population the behavior of an in situ benzene contaminated soil-block was simulated using experimental data published by Martins (2010). As an application of the studied procedures, two PVC columns filled with undisturbed residual soil were simulated (lysimeters). The lysimeters were vertically provided with a contaminant solution in the vertical direction opposite to gravity, in order to evaluate along the column, the biodegradation of benzene compounds and the influence of the ethanol in the process. In addition, was evaluated the delay of benzene degradation due to the presence of ethanol in the saturated zone and the increasing in biomass in the region of simulated model. This study also shows a description of the program used and its formulation. Finally, the results of the analyses and the incorporation of the model performed are presented, conclude and commented.

Les capteurs d’oxygène sont le plus grand apport dans la technologie des emballages actifs parce qu’ils permettent de retarder la dégradation oxydante des aliments et ainsi éviter la perte de saveurs et le développement microbien au sein des aliments. Bien que le développement des emballages actes existe depuis les années 70 dans des pays producteur agricole, la recherche sur ces emballages reste encore embryonnaire, en particulier sur les critères techniques portant sur l’absorption d’oxygène de films. Cette thèse constitue une contribution sur l’étude des cinétiques d’absorption d’oxygène de l’huile de lin comme capteur d’oxygène. L’oxydation de l’huile et d’esters insaturés (composé modèle de l’huile) est suivie sous différentes conditions d’exposition (températures comprises entre 40-110°C et pressions partielles d’oxygène entre 0 et 1 bar). Expérimentalement, on propose de caractériser l’absorption d’oxygène liée à l’oxydation de l’huile par thermogravimétrie (ATG), suivi de concentration d’oxygène et titrage de peroxide. Un modèle cinétique basé des schémas classiques avec décomposition des hydroperoxydes, est proposé pour simuler l’oxydation de l’huile de lin et des esters insaturés modèles. Ce modèle est ensuite extrapolé à des films de différentes épaisseurs de polypropylène (PP) contenant 1% d’huile de lin en considérant que cette dernière est bien dispersé dans la matrice PP et que la diffusion d’oxygène est pilotée par la matrice PP. / Oxygen scavengers (OS) are one of the most important technology of active packaging, because prevents oxidative degradation related with off-flavours, off-odours and microbial growth in food. Although active packaging has been proposed since 1970s, in developing countries with a large agricultural base, active packaging still remains unexplored both in terms of application and research, there is a lack of technical criteria on O2 scavenging films, labels, sheets, and trays. This PhD thesis is a contribution in the study of linseed oil as active ingredient for OS providing a kinetic characterization of its thermo-oxidation between 40°C and 110°C in atmospheres with different oxygen concentration. In the experimental approach, innovative application of TGA was proposed to study oxygen uptake capacity complemented by headspace and peroxide value measurements. The kinetic model, derived from a classic mechanistic scheme where initiation of thermo-oxidation results from decomposition of hydroperoxides, was capable to simulated linseed oil oxidation, and also oxygen absorptions of polypropylene films, of different thickness, containing 1% of linseed oil, with hypotheses of well dispersion of linseed oil in PP matrix, and oxygen diffusion governed by the PP matrix.

Le PEI et le PEEK sont des thermoplastiques aromatiques haute performance. Il est envisagé de les utiliser comme matrice de structures composites en environnement de moteur d’avion. En conditions de service, ils seront soumis à des cycles hygrothermiques complexes consistant à des vieillissements thermo-oxydant jusqu’à 180 °C en continu et des vieillissements humide à 70 °C dans 85 % HR. Leur durabilité ayant fait l’objet de peu de travaux de recherche, l'objectif de cette thèse était d’étudier les effets isolés et combinés des vieillissements thermique et humide de ces deux matrices. Tout d’abord, des films minces de PEI et de PEEK ont été oxydés à différentes températures (entre 180 et 320 °C) et pressions partielles d’oxygène (entre 0,21 et 50 bars). Ils ont ensuite été caractérisés aux différentes échelles structurales pertinentes : moléculaire, macromoléculaire, morphologique et macroscopique. Cette caractérisation multi-techniques et multi-échelles a permis de déterminer leurs mécanismes de dégradation thermique. Ensuite, le vieillissement humide du PEI et du PEEK a été étudié entre 30 et 70 °C, entre 10 et 100 % HR, avant et après vieillissement thermique. A partir d’une compilation des données de la littérature pour une large variété de polymères contenant un seul type de groupe polaire dans l’unité monomère, des relations structure - propriété de transport de l'eau ont été établies. Elles confirment que l’hydrophilie et la diffusion d’eau résultent essentiellement d’interactions moléculaires entre les molécules d’eau et les groupes polaires de la matrice polymère. Enfin, un modèle cinétique de thermo-oxydation a été établi pour les matrices PEI et PEEK et a été interfacé avec les relations structure – propriété de transport d’eau. Il permet de simuler l’ensemble des données expérimentales accumulées dans ce travail de thèse. / PEI and PEEK are high performance aromatic thermoplastics. They are planned to be used as matrices of composite materials in aircraft engine environment. In service conditions, they will be subjected to complex hygrothermal cycles consisting in a series of thermo-oxidative agings up to 180 °C and humid agings at 70 °C in 85 % RH. As their durability has been little studied in the literature, the aim of this PhD thesis is to study the separated and combined effects of thermal and humid agings of these two matrices. At first, thin PEI and PEEK films have been oxidised at different temperatures (between 180 and 320 °C) and oxygen partial pressures (between 0.21 and 50 bars). There have been then characterized at different structural scales: molecular, macromolecular, morphological and macroscopic. This multi-technique and multi-scale characterization has enabled the determination of their thermal degradation mechanisms. Then, the humid aging of PEI and PEEK has been studied between 30 and 70 °C and between 10 and 100 % RH, before and after thermal aging. From a literature compilation of data for a large variety of polymers containing a single type of polar group in their monomer unit, structure – water transport property relationships have been established. They confirm that hydrophilicity and water diffusion result essentially from the molecular interactions between water molecules and polar groups in polymer matrices. Finally, a thermos-oxidation kinetic model has been established for PEI and PEEK matrices and has been juxtaposed with the structure – water transport property relationships. It enables to simulate all the experimental data obtained in this PhD work.

Les résines époxy/amine obtenues grâce au mélange d’un prépolymère époxy et d’un durcisseur amine, sont utilisées dans divers domaines d’applications : peinture, potting de composés électroniques... L’objectif de cette thèse est la prédiction de la durée de vie de trois résines : DGEBA ou DGEBU/cycloalipahtique diamine, DGEBA/aliphatique diamine, soumises à un vieillissement thermo-oxydant. Pour cela, une étude multi échelle de l’oxydation est réalisée à différentes conditions de température (de 110°C à 200°C) et de pression d’oxygène (0,2 bars et 50 bars). A l’échelle moléculaire, la spectroscopie IRTF a montré la formation d’amides et de carbonyles. A l’échelle macromoléculaire, les coupures de chaînes semblent prédominantes lorsque le durcisseur est une diamine cycloaliphatique. En revanche, lorsque le système contient des séquences méthylènes portées par des segments flexibles, elles peuvent induire un mécanisme de réticulation qui peut prédominer. Ces résultats gouvernent l’évolution des propriétés fonctionnelles : la fragilisation mécanique et la dégradation des propriétés diélectriques de DGEBA/cycloaliphatique diamine se produit pour des temps d’exposition inférieurs à ceux observés pour DGEBA/aliphatique diamine. L’extrapolation des durées de vie est réalisée grâce à une modélisation cinétique basée sur un schéma mécanistique de l’oxydation des trois résines. La résolution de ce schéma cinétique permet la modélisation de l’ensemble des résultats expérimentaux (concentration en produits d’oxydation, coupures de chaînes et réticulation) pour une oxydation homogène ou bien sur des échantillons épais présentant un gradient d’oxydation. Les contraintes mécaniques engendrées lors de l’oxydation d’un échantillon épais (3 mm) de DGEBA/cycloaliphatique diamine ont été simulées afin de prédire la fissuration spontanée. / Epoxy/amine resins are thermoset materials made of epoxy prepolymer and amine hardener. Those materials are used in several industrial applications, such as paint or to encapsulate electronics. The main goal of this work is to predict lifetime of three resins: DGEBA or DGEBU/cycloaliphatic diamine, DGEBA/aliphatic diamine, in thermo-oxidative environment. In order to achieve this, a multi scale study of the oxidation is done, at several temperatures (from 110°C to 200°C) and oxygen partial pressures (0,2 bars et 50 bars). At molecular scale, the formation of amides and carbonyls has been noticed. At macromolecular scale, chain scission has been observed in epoxy/cycloaliphatic diamine but in DGEBA/aliphatic diamine cross linking seems to be predominant. Those properties are directly related to functional properties: mechanical and dielectric break down appear later in DGEBA/aliphatic diamine than in epoxy/cycloaliphatic diamine. The extrapolation of life is possible thank to kinetic modelling, based on chemical mechanistic scheme. The resolution of this kinetic scheme allowed us to model all experimental data (concentration of oxidation products, chain scission and cross linking), either in homogenous oxidation and in thick samples (3 mm). Stresses induced by oxidation in a thick sample of DGEBA/cycloaliphatic diamine have been simulated thanks to Matlab ® and finite elements by Abaqus ®.

[pt] A produção e o uso de DRI (Direct Reduction Iron) são cada vez maiores hoje em dia nos países desenvolvidos, essencialmente pela redução do preço do gás natural e do sucesso da tecnologia de extração de gás de xisto. Além disso, o menor teor de elementos contaminantes em DRI do que nas sucatas de aço, levou-o a ser considerado uma boa alternativa como carga metálica para o Forno Elétrico a Arco (FEA) e o processo no conversor LD /BOF. Os custos operacionais e os problemas ambientais, são atualmente dois fatores tecnológicos importantes a serem considerados na otimização da produção de DRI, afetando à produtividade, sustentabilidade e competitividade do processo industrial. O teor de carbono do DRI, por exemplo, tem se tornado cada vez mais importante, devido à sua capacidade de gerar energia química nas aciarias, complementando o uso de energia elétrica nos FEA e os inputs energéticos no LD. Este trabalho foi uma das partes do programa de cooperação entre a Companhia de Mineração Samarco e o Grupo de Siderurgia da Pontifícia Universidade Católica do Rio de Janeiro / PUC-Rio, que tratou especificamente do modelo cinético para a metalização e carburização simultâneas em fornos RD tipo cuba. No âmbito deste objetivo o reator foi dividido em três zonas: Redução, Transição e Resfriamento. Foram também consideradas mais três camadas concêntricas: periférica, media e central. Com base nos resultados obtidos em experiências que abrangeram diferentes tipos de pelotas, empregando misturas gasosas semelhantes às presentes nos processos industriais e obedecendo às suas correspondentes semelhanças fluidodinâmicas, foi desenvolvido um software, denominado METCARB, que incluiu na sua elaboração todas as equações e modelos cinéticos desenvolvidos experimentalmente nas três zonas do reator RD. A parte experimental foi, portanto, uma das partes principais do presente trabalho, conjuntamente com a concepção do modelo computacional e suas validações industriais. Com o METCARB, as previsões acerca da metalização e carburização simultâneas, em qualquer região interna do forno, se tornou possível, utilizando como entradas as dimensões do forno, medidas de temperaturas, composições dos gases, etc. Os resultados de metalização e carburização, também em formato gráfico, são gerados pelo sistema computacional, bem como as curvas cronométricas e tabelas de resultados. Estudos sobre dois casos reais foram realizados, a fim de validarem a ferramenta computacional desenvolvida. Constatou-se que a carburização do ferro metálico sempre ocorre simultaneamente com a redução dos óxidos de ferro e que, dependendo da temperatura e composição dos gases, pode ocorrer precipitação de finos de carbono. As simulações realizadas com o modelo METCARB mostraram que na periferia da ZR é gerado um DRI mais metalizado que na região do centro. Fenômeno contrário foi, entretanto, verificado com a carburização; Nas condições experimentais empregadas neste trabalho, os valores médios obtidos para a carburização e a metalização, no final da ZR, variam entre 0,4 - 0,7 por cento C, e 92 por cento - 97 por cento, respectivamente; Constatou-se não ocorrer progresso do grau de redução nas zonas de Transição (ZT) e de Arrefecimento (ZA), ou seja, mantiveram-se ao longo dessas zonas os valores de metalização obtidos no fundo da ZR; A influência do vapor de água no processo da carburização no caso estudado (0 - 4.25 por cento H2O) leva menor porcentagem de carburização (2,7 por cento C – 2,35). / [en] The production and the use of DRI (Direct Reduction Iron) are increasing today in developed countries, mainly by reducing the price of natural gas and the success of shale gas extraction technology. In addition, the lower level of contaminants in DRI than in metal scraps, led it to be considered a good alternative as metallic charge for the Electric Arc Furnace (EAF) and the process in LD / BOF converter. This work was one part of the cooperation program between Samarco Mining Company and Steel Group of the Pontifical Catholic University of Rio de Janeiro / PUC-Rio, which specifically dealt with the kinetic model for the metallization and carburization simultaneous in RD shaft furnaces. Under this purpose the reactor was divided into three zones: Reduction, Transition and Cooling. There were also three concentric regions considered: peripheral, media and center. Based on the results from experiments covering different types of pellets, using gas mixtures similar to those present in the industrial processes and obeying their corresponding fluid dynamic similarities, it developed a software called METCARB, which included in its preparation all kinetic equations and models developed experimentally in the three reactor zones of RD. The experimental part was therefore a major part of this work, together with the design of computational model and its industrial validations. With METCARB predictions about the simultaneous metallization and carburization in any internal region of the furnaces, it became possible, using as inputs the dimensions of the furnace, temperature measurements, compositions of gases, etc. The results of metallization and carburization also in graphic format are generated by the computer system, and the chronometric curves and results tables. Studies on two real cases were performed in order to validate the developed computational tool. It was found that the carburization always occurs simultaneously with the reduction of iron oxides and, depending on the temperature and composition of the gases; precipitation of fine carbon may occur. The simulations with METCARB model showed that the periphery of the ZR generated more DRI metallized than the center area. A contrary phenomenon has been verified with the carburization; With the experimental conditions used in this study, averages values obtained for the metallization and carburization in the final ZR vary between 0.4 - 0.7 percent C and 92 percent - 97 percent, respectively; It was not found that the progress of reduction degree occurred in the transition (ZT) and cooling (ZA) regions, in other words, it remained along these zones of the metallization values obtained at the bottom of ZR; The influence of water vapor in the carburization process in the case studies (0 - 4.25 percent H 2 O) takes a smaller percentage of carburization (2.7 percent C - 2.35).

Les énergies non-renouvelables ont été d’un apport capital dans l’industrialisation et l’urbanisation dans les derniers centenaires. L’exploitation excessive des réserves d’hydrocarbures et son impact environnemental ont contribué au developpement de plusieurs technologies durables à caractère néo-carbone neutre. A cet effet, les processus biologiques comme la fermentation pourraient être exploités pour convertir biologiquement le hydrates de carbone en énergies comme l’hydrogène (H2) ou des acides organiques commercialement rentables. Ce travail a étudié les techniques d’ingénierie pour améliorer la synthèse simultanée d’H2 et d’acide lactique à travers des conditions de fermentation capnophile lactique (CLF) par une souche de labo de Thermotoga neapolitana.En un premier temps, une comparaison génotypique entre la souche de labo et celle sauvage a révélé une ressemblance de 88,1 (±2,4) %. En plus, les analyses du génotypage par RiboPrint® et par spectroscopie de masse matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF MS) ont montré une différentiation génétique au-delà du niveau sous-espèce ; et par conséquent la souche de labo a été proposée comme sous-espèce, T. neapolitana subsp. lactica. Basé sur la caractérisation phénotypique, la souche de labo produisait 10-90% plus d’acide lactique que celle sauvage sous les mêmes conditions sans pour autant affecté le taux de production d’H2.La souche de labo a donc été étudiée pour aussi bien optimiser les conditions de croissance que pour estimer les paramètres cinétiques de croissance. Un nouveau modèle cinétique basé sur les principes de fermentation à l’obscurité (DF) et les expressions mathématiques Monod ont été développés pour permettre la simulation de la croissance en biomasse, la consommation de substrat, et la formation de produit. Le modèle n’a cependant pas pu faire une estimation des acides acétique et lactique avec précision du fait que le modèle DF n’a pas considéré la carboxylation de l’acide acétique en acide lactique par l’enzyme pyruvate ferrédoxine oxydoréductase (PFOR) sous les conditions CLF.Le model a été associé avec le mécanisme CLF et les paramètres cinétiques ont été recalibrés. Les paramètres cinétiques que sont le taux d’absorption spécifique maximum (k), la constante semi-saturation (ks), le coefficient en rendement biomasse (Y), et le taux de décomposition interne (kd) étaient de 1,30 l/h, 1,42 g/L, 0,12 et 0,02 l/h. Fait intéressant, le nouveau modèle CLF s’est parfaitement adapté avec les résultats expérimentaux et a estimé que près de 40-80% de la production d’acide lactique est attribué au recyclage de l’acide acétique et le CO2.En plus, l’adsorption de l’acide lactique par le carbone actif et les résines polymères anioniques a été appliquée avec succès comme technique de transformation en aval dans la récupération et la purification de l’acide lactique à partir du modèle de fermentation type T. neapolitana. Pour ce faire, ce travail de recherche constitue une étape majeure dans le domaine de la fermentation bactérienne utilisable pour de vastes applications scientifiques prenant en compte le développement d’énergies renouvelables et la production industrielle d’acide lactique / The environmental impact of excessive exploitation of fossil fuel reserves has inspired the innovation of several sustainable neo-carbon-neutral technologies. To that end, the biological processes like fermentation may be leveraged to bioconvert carbohydrate-rich feedstocks to fuels like hydrogen (H2) or commercially valuable organic acids like lactic acid. This research work investigated the engineering techniques for improving simultaneous synthesis of H2 and lactic acid under capnophilic (CO2-dependent) lactic fermentation (CLF) conditions by a lab strain of Thermotoga neapolitana.Primarily, the genotypic comparison between the lab strain and the wild-type revealed DNA homology of 88.1 (± 2.4)%. Genotyping by RiboPrint® and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses showed a genetic differentiation beyond subspecies level, hence the lab strain was proposed as a new subspecies, T. neapolitana subsp. lactica. The lab strain produced 10-90% more lactic acid, based on the phenotypic characterization, than the wild-type strain under similar operating conditions without impairing the H2 yield.The lab strain was then studied to optimize the growth conditions as well as to estimate the growth kinetic parameters. A new mathematical model based on the dark fermentation (DF) principles and Monod-like kinetic expressions was developed to enable the simulation of biomass growth, substrate consumption and product formation. The model failed to estimate acetic and lactic acid accurately, as the DF model did not consider the carboxylation of acetic acid to lactic acid by the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme under CLF conditions. The model was then incorporated with the CLF mechanism and the kinetic parameters were recalibrated.The calibrated kinetic parameters, i.e. maximum specific uptake rate (k), semi-saturation constant (kS), biomass yield coefficient (Y) and endogenous decay rate (kd) were 1.30 1/h, 1.42 g/L, 0.12 and 0.02 1/h, respectively, under CLF conditions. The new CLF-based model fitted very well with the experimental results and estimated that about 40-80% of the lactic acid production is attributed to the recycling of acetic acid and CO2.In addition, the adsorption of lactic acid by activated carbon and anionic polymeric resins was successfully applied as a downstream processing technique for the recovery of lactic acid from a model T. neapolitana fermentation broth. This research work serves as a practical milestone in the field of microbial fermentation with a scope for wider scientific applications, including the development of bio-based renewable energy and industrial lactic acid production

Cette thèse s’inscrit dans le développement et l’optimisation d’un panel de catalyseurs dopés ou non dopés pour le traitement des eaux usées par un Procédé d’Oxydation Avancée (POA), la photocatalyse hétérogène solaire. Ce procédé de traitement tertiaire pour la dépollution de molécules organiques biorécalcitrantes est limité par l’absorption des catalyseurs dans le domaine de l’UV ne représentant que 5 % du spectre solaire reçu à la surface de la Terre. L’objectif de ce travail est de comparer les efficacités photocatalytiques sous rayonnement UV, visible et solaire dans le but d’améliorer les efficacités dans le domaine de l’UV, de développer un catalyseur exploitant efficacement le rayonnement visible et de définir les paramètres clés régissant les réponses photocatalytiques. Dans cette optique, une étude a été menée sur les catalyseurs de ZnO dopés ou non dopés. L’ensemble des catalyseurs à base de ZnO ont été synthétisé par un seul et même procédé, le sol-gel couplé à un séchage en conditions supercritiques. Les caractérisations structurales, morphologiques, chimiques, optiques et optoélectroniques ont été réalisées en vue de définir leurs paramètres physico-chimiques pour maitriser les conditions de synthèses des catalyseurs. Elles ont également montré que le ZnO dopé décale sa bande d’absorption vers le domaine du visible. Les expérimentations photocatalytiques ont été conduites à l’aide d’un banc de mesure photocatalytique dans le domaine de l’UV, du visible et du solaire. Une attention particulière est portée sur un polluant modèle, le pyriméthanil. En parallèle, ces expérimentations ont été couplées à un modèle cinétique. Les nanoparticules de Zn1-xMxO (M : Ca, Al, Li, V, In, Co, P…) présentent des réponses photocatalytiques prometteuses dans le domaine du visible. Une corrélation a également été mise en évidence entre les propriétés physico-chimiques des catalyseurs et l’efficacité à produire des radicaux. Par ailleurs, une étude plus approfondie a été menée sur le Zn0,90Ca0,10O. Cette étude révèle la présence de défauts structuraux jouant un rôle essentiel sur les réponses photocatalytiques. / This thesis is part of the development and optimization of a doped and undoped panel of catalysts for the treatment of waste water based on an Advanced Oxidation Process (AOP), solar heterogeneous photocatalysis. This tertiary process for bio-recalcitrant organic molecules clean up is limited by the catalysts absorption in the UV range which represent only 5 % of the solar spectrum received on the earth surface. The aim is to compare photocatalytic efficiency under UV, visible and solar irradiation in order to improve efficiency in the UV range, to develop a catalyst which operates effectively under visible irradiation and to define key parameters governing the photocatalytic activities. In this context, a study is performed on doped or undoped ZnO based catalysts. All of ZnO based catalysts are synthesized by the same process, the sol-gel process under supercritical drying conditions. Structural, morphological, chemical, optical and optoelectronical characterizations is carried out to define their physico-chemical parameters in order to control the synthesis conditions of these catalysts. Doped ZnO also showed an absorption edge shift toward the visible range. Photocatalytic experiments are carried out with a photocatalysis optical bench in the UV, visible and solar range. Particular attention is paid on a model pollutant, pyrimethanil. In parallel, these experiments are coupled to a kinetic model. Nanoparticles of Zn1-xMxO (M : Ca, Al, Li, V, In, Co, P…) showed encouraging photocatalytic activities in the visible range. A correlation is showed between the physico-chemical properties of the catalysts and the radicals production efficiency. Furthermore, an extensive study is done on Zn0,90Ca0,10O. This study reveals the presence of structural defects playing a main role on the photocatalytic activities.

Plant cell and tissue cultivations are of growing interest for the production of structurally complex and expensive plant-derived products, especially in pharmaceutical production. Problems with up-scaling, low yields and high-priced process conditions result in an increased demand for models to provide comprehension, simulation, and optimization of production processes. In the last 25 years, many models have evolved in plant biotechnology; the majority of them are specialized models for a few selected products or nutritional conditions. In this article we review, delineate, and discuss the concepts and characteristics of the most commonly used models. Therefore, the authors focus on models for plant suspension and submerged hairy root cultures. The article includes a short overview of modeling and mathematics and integrated parameters, as well as the application scope for each model. The review is meant to help researchers better understand and utilize the numerous models published for plant cultures, and to select the most suitable model for their purposes.

No description available.

No description available.