Sur le plan moléculaire, le transport de petites molécules à travers les bicouches lipidiques est un processus fondamental. L'objectif de ce travail consiste a étudier les différents mécanismes de transfert de molécules hydrophiles à travers la bicouche liposomale. La calcéine a été choisie comme molécule hydrophile modèle pour simuler la vectorisation de principes actifs. Dans une première étape, la formulation des liposomes a été optimisé en considérant ses propriétés physico-chimiques (taille, efficacité d'encapsulation, fluidité et etc.) par différentes méthodes (DSC, TEM, SAXS et etc). Les résultats montrent que la taille moyenne, le potentiel zêta, Tc, l'efficacité d'encapsulation et la fluidité, sont influencés par la composition lipidique des liposomes. Les interactions entre les molécules hydrophiles encapsulées et le vecteur ont été étudiés par spectroscopie Raman, balance de Langmuir et analyse thermique différentielle. Les résultats obtenus montrent que la calcéine est capable d'interagir avec le groupement polaire de la phosphatidylcholine, en s'intercalant entre les chaînes acyles et modifiant de ce fait l'organisation de la membrane. La perméabilité des membranes à la calcéine a d'abord été évaluée sur la base d'une cinétique du premier ordre par spectrofluorimètrie. L'effet de la composition en lipides sur la fluidité membranaire a été étudié en fonction des conditions environnementales. Un modèle simulant les conditions de la digestion a été élaboré pour estimer la vitesse de libération du calcéine à travers la bicouche liposomale, son coefficient de partage, en utilisant l'AFM et la méthode STED. Les résultats obtenus ont confirmé que la calcéine diffuse lentement à travers la membrane liposomale sans pour autant déstructurer le liposome / From a molecular point of view, transport of small molecules across lipid bilayers is a fundamental and functional process. The release of efficacious dose of bioactive-entrapped in liposome depends on different parameters such as liposome permeability, bioactive structural properties and strength of liposome / bioactive interaction. The aim of this study was investigation the possible mechanisms of hydrophilic molecules transfer through liposomal bilayer. Calcein was chosen as model of hydrophilic drugs. In the first step, we optimized liposome formulation by considering its physicochemical properties (size, encapsulation efficiency, fluidity and etc.) by different methods such as DSC, TEM, SAXS, DLS, NMR and Spectroufluremtere. The reported results show that mean size, zeta potential, Tc, entrapment efficiency and fluidity were influenced by liposome lipid composition. Then, we tried to investigate hydrophilic bioactive agents? interaction with liposome by Raman Spectroscopy, Langmuir Balance and Differential Scanning Calorimetry. The obtained results indicated that calcein is being able to interact with the choline polar-head group of the lipids but probability it could intercalate into the acyl chains and disturb the chain order. Finally, the permeability of calcein across some liposome membranes was first evaluated on the basis of the first-order kinetics by spectrofluorometer. Second, the composition/fluidity effect of liposome as well as the incubation temperature/pH effect was investigated. Furthermore, a model simulating the conditions of digestion was developed to estimate the partition coefficient and to determine the mechanism transfer through liposomal bilayer by using AFM and STED methods. The results confirmed that calcein permeates slowly through liposomal membrane by diffusion without liposome disruption

Doctor Educationis / In summary, it has been shown during this study that bimetallic Fe and Mn containing catalysts can be prepared by wet impregnation and not by ion exchange because of the competition between two different metals at different oxidation number. Only a single metallic phase catalyst could be prepared successfully by using ion exchange. / South Africa

Aucune étude physicochimique majeure des eaux du fleuve Chari n’a été réalisée malgré le fait que depuis l’indépendance du Tchad (1960), quelques usines agroalimentaires, des hôpitaux, des usines textiles, des abattoirs… se soient installés sur ses rives. Les résultats des analyses obtenus après un suivi de 2008 à 2010 ont montré la présence des métaux traces dans le Chari. Sur l’ensemble des échantillonnages d’eau analysés, le fer est l’élément métallique majeur devant le manganèse, le zinc et le nickel. Ces résultats varient en fonction des périodes de prélèvement (saison des pluies ou saison sèche). La plupart des valeurs obtenues dépassent largement les seuils acceptables selon les recommandations de l’OMS. La présence des métaux traces dans le Chari résulte aussi bien du processus naturel que de l’activité humaine. Bien que les concentrations de Ni, Cr, Co, Mn et Zn ne soient pas aussi élevées que celle du fer, le profil de répartition de ces éléments entre les différents sites montre une certaine similarité. Les valeurs moyennes de pH indiquent que les effluents ont un caractère légèrement alcalin, tandis que celles relatives à l’oxygène dissous sont satisfaisantes. De ce fait, les eaux du Chari sont impropres, du point de vue physicochimique voire potentiellement dangereuse pour la santé environnementale et humaine. La lutte contre les pollutions doit être entreprise le plus précocement possible / No physicochemical major study of water of the Chari river was carried out in spite of the fact that since the independence of Chad (1960), some food agro factories, hospitals, textile factories, slaughter-houses… were installed on its banks. Also, this work aims to the “contribution to the analytical study of the pollutants (particularly heavy metals) in waters of the Chari river crossing the town of N’Djamena” using the suitable chemical techniques. The results of the analyses obtains after a follow-up from 2008 to 2010 showed the presence of trace metals in the Chari river. On the whole of analyzed water samplings, iron is the major metal element in front of manganese, zinc and nickel. These results vary according to the periods of taking away( rainy season or dry season). The majority of the values obtained largely exceed the acceptable thresholds according to recommendations of WHO. The presence of trace metals in the Chari river results as well from the natural process as of human activity. Although the concentrations of Ni, Cr, Co, Mn, Cu and Zn are not as high as those of iron, the profile of distribution of these elements between the various sites shows a certain similarity. The average values of pH indicate that the effluents are slightly alkaline, while those relating to dissolved oxygen are satisfactory. So the waters of Chari are unsuitable, from the physicochemical point of view, even potentially dangerous for environmental and human health. The control of pollution must be undertaken the most preciously as possible

There is interest in the pharmaceutical area in the use of sponges, produced with biopolymers, as matrices for the controlled release of drugs. The biopolymers for pharmaceutical applications must have physicochemical and appropriate mechanical and biocompatibility. Alginate is a biopolymer, obtained from the alginic acid, which has been largely studied due to its ability to incorporate and promote the controlled release of drugs. Gelatin is a protein obtained by hydrolysis of collagen and has been used in obtaining produce hydrogels and sponges with therapeutic properties. Usnic acid (UA) is the most abundant metabolite of the lichen Cladonia substellata has proven antimicrobial, anti-inflammatory, analgesic and healing activities. In this context, the aim of this work was to physicochemical characterization and evaluate the effect of alginate-gelatin sponges, containing usnic acid on wound healing in rats. The sponges were prepared from gelatin, alginate and incorporated with usnic acid in concentrations of 1 and 5% (m/v) and freeze dried. For material characterization were used thermogravimetry/derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), infrared absorption spectroscopy (FTIR), scanning electron microscopy (SEM) and mechanical properties tests. The biological assay was performed with 36 rats divided into three groups: without treatment (CTR); treated with inert sponge (ALG/GEL); and treated with the sponge containing usnic acid 5% (AU 5%). After 7 and 14 days, six animals from each group were submitted to euthanasia for histological analysis. The average content of usnic acid was 60.03 and 97.38% for sponges in 1 and 5%, respectively. DSC analysis results show the absence of endothermic peak of UA pure, indicating that the drug was incorporated into the polymer system. TG/DTG curves corroborate with the DSC data and showed that the incorporation of usnic acid has not changed the thermal behavior of sponges. The FTIR spectra of sponges showed a sum corresponding to the event of usnic acid, alginate and gelatin bands, indicating the presence of these compounds in the system. The analysis by SEM showed that the incorporation of different concentrations of UA, in sponges promotes changes in microscopic structure, resulting in different mechanical behaviors. The biological assays in 7 days, showed an inflammatory reaction in the marginal and central portions of the wound, but ALG/ GEL and AU 5% groups, promoted an acceleration in the formation of granulation tissue. In 14 days, in the AU 5% group, was a clear reduction of the inflammatory component even in the central portion of the wound. Additionally, there was a marked reduction in vascular component, when compared to the CTR group with a homogeneous pattern of colagenization type III in the entire length of the scar. In conclusion, the incorporation of usnic acid has not changed the thermal stability of sponges and, in addition, the use of alginate-gelatin sponge and promotes the wound healing and the incorporation of the drug eases wound contraction and a homogeneous deposition of collagen, avoiding the formation of hipertrophic scars. / Existe um interesse na área farmacêutica no uso de esponjas, produzidas com biopolímeros, como matrizes para a liberação controlada de fármacos. Os biopolímeros para aplicações farmacêuticas devem possuir propriedades físico-químicas e mecânicas adequadas, além de serem biocompatíveis. O alginato é um biopolímero, obtido a partir do ácido algínico, que tem sido largamente estudado devido a sua capacidade de incorporar compostos e promover a liberação controlada de fármacos. A gelatina é uma proteína obtida pela hidrólise do colágeno e vem sendo empregada na obtenção de hidrogéis e esponjas com propriedades terapêuticas. O ácido úsnico (AU) é o metabólito mais abundante do líquen Cladonia substellata e possui comprovada atividade antimicrobiana, anti-inflamatória, analgésica e cicatrizante. Neste contexto, o objetivo deste trabalho foi caracterizar físico-quimicamente e avaliar o efeito de esponjas de alginato-gelatina, contendo ácido úsnico sob a cicatrização em ratos. As esponjas foram preparadas a partir do alginato e gelatina, incorporadas com ácido úsnico, nas concentrações de 1 e 5% (m/v) e liofilizadas. Para caracterização do material foram utilizadas a análise termogravimétrica/termogravimétrica derivada (TG/DTG), a calorimetria exploratória diferencial (DSC), espectroscopia de absorção na região do infravermelho (FTIR), microscopia eletrônica de varredura (MEV) e testes de propriedades mecânicas. O ensaio biológico foi realizado com 36 ratos divididos em três grupos: sem tratamento (CTR); tratados com esponja inerte (ALG/GEL); e tratados com esponja contendo ácido úsnico a 5% (AU 5%). Após 7 e 14 dias, seis animais de cada grupo foram eutanasiados para análise histológica. O teor médio de ácido úsnico foi de 60,03 e 97,38% nas esponjas de 1 e 5%, respectivamente. Os resultados da análise de DSC mostram a ausência do pico endotérmico referente ao AU puro, indicando que o fármaco foi incorporado ao sistema polimérico. As curvas TG/DTG corroboram com os dados do DSC e mostraram que a incorporação do ácido úsnico não alterou o perfil geral da decomposição térmica das esponjas. Os espectros FTIR das esponjas mostraram um somatório de eventos correspondentes às bandas do ácido úsnico, alginato e gelatina, indicando a presença dos referidos compostos no sistema. A análise por MEV mostrou, que a incorporação de diferentes concentrações de AU, nas esponjas promove alterações na estrutura microscópica, resultando em diferentes comportamentos mecânicos. Os ensaios biológicos em 7 dias, mostram uma reação inflamatória nas porções centrais e marginais da ferida, porém os grupos ALG/GEL e AU 5%, promoveram uma aceleração na formação de tecido de granulação mais maduro. Em 14 dias, no grupo AU 5%, foi nítida a redução do componente inflamatório mesmo na porção central da ferida. Adicionalmente, observou-se uma marcante redução na rede vascular, quando comparado ao grupo CTR, acompanhada de um padrão homogêneo de colagenização tipo III em toda a extensão da cicatriz. Em conclusão, a incorporação do ácido úsnico não alterou a estabilidade térmica das esponjas e, além disso, o uso de esponja de alginato e gelatina favorece a cicatrização de feridas e a incorporação do fármaco facilita a contração da ferida e uma deposição homogênea de colágeno, evitando a formação de cicatrizes antiestéticas.

O mel é um alimento doce feito por abelhas a partir do néctar das flores. Estudos consideram o mel um adoçante natural, fonte de compostos antioxidantes, que quando incluídos na dieta tornam-se aliados contra danos oxidativos. No entanto, a composição do mel é muito variável, pois depende da fonte floral que o origina, das condições ambientais onde é produzido e do modo como é recolhido e processado. A região Sul distingue-se das demais regiões brasileiras em função do seu clima e vegetação. Além disso, o somatório dos principais estados da região Sul representa 49 % da produção de mel do país, destacando-se o estado do Rio Grande do Sul (RS) como o maior produtor. Uma recente pesquisa demonstrou que outro produto da colmeia, o pólen apícola, produzido na mesma região, apresentou maior capacidade antioxidante quando comparado ao pólen produzido em outras regiões do país, tornando oportuna a busca por méis com possíveis efeitos benéficos à saúde. Nesse contexto, o presente trabalho teve como objetivo caracterizar os méis de Apis mellifera, produzidos no estado do RS, quanto as propriedades físico-químicas e antioxidantes, e estabelecer correlações com a origem botânica. Para isso, foram obtidas 52 amostras, adquiridas na Casa do Mel, em Viamão, no RS, de diversas origens botânicas e diferentes locais do estado. As propriedades físico-químicas avaliadas foram: análise melissopalinológica, umidade, cinzas, condutividade elétrica, pH e acidez livre, cor, atividade diastásica, açúcares, hidroximetilfurfural (HMF) e reações qualitativas de Fiehe e Lund, de acordo com as análises preconizadas pelas normas brasileira e internacional. A avaliação das propriedades antioxidantes consistiu na identificação e quantificação dos compostos fenólicos por cromatografia líquida de alta eficiência; determinação da capacidade redutora do Folin-Ciocalteu; determinação de flavonoides totais; capacidade de absorção de radicais de oxigênio (ORAC); determinação do poder redutor do ferro (FRAP); e sequestro do radical estável DPPH. Os resultados para a análise físico-química caracterizaram os méis em: monoflorais (eucalipto, aroeira, quitoco, uva japão, flor do campo e laranjeira) e heterofloral; a umidade apresentou média de 18,3±0,7 % (máx. 20); o valor médio para cinzas foi de 0,3±0,2 % (máx. 0,6); a condutividade elétrica foi de 0,59±0,2 mS.cm-1 (máx. 0,8); o pH com média de 4,18±0,3 e a acidez livre com 32±9,8 mEq.Kg-1 (máx. 50); a cor variou do extra branco ao âmbar; a média da atividade diastásica foi de 16,4±11,0 °Gothe (mín. 8); as médias para frutose e glicose foram, respectivamente, 37,9±1,4 e 32±2,5 g.100-1, onde a razão frutose/glicose foi de 1,2±0,1; o teor médio de HMF foi de 5,6±5,8 mg.Kg-1 (máx. 60); e as reações de Fiehe e Lund apresentaram, respectivamente, resultados negativo e positivo para todas as amostras, indicando a pureza dos méis analisados. No que concerne à análise de antioxidantes, os ácidos gálico, cinâmico e o p-cumárico, e os flavonoides quercetina e miricetina, foram identificados. O teor de fenólicos e flavonoides totais foram de 61,3±18,3 mgEAG.Kg-1 e 0,7±0,7 mgQE.100g-1, respectivamente. A capacidade antioxidante pelo método ORAC foi de 7,8±4,3 mmolET.Kg-1; pelo ensaio FRAP foi de 1,2±0,6 &#181;molET.g-1; e pelo método DPPH (EC50) foi de 72,4±89,8 mg.ml-1. Os méis apresentaram-se de acordo com os parâmetros físico-químicos exigidos pela legislação brasileira e recomendações internacionais, para o controle de qualidade do mel. A capacidade antioxidante foi semelhante à encontrada na literatura científica. As espécies botânicas que apresentaram maior atividade antioxidante foram eucalipto e aroeira. O conteúdo de fenólicos totais não apresentou diferença estatística entre esses dois tipos de méis, no entanto o teor de flavonoides nos méis de aroeira foi maior (p<0,05) do que o referido nos méis de eucalipto. O ácido gálico foi o composto majoritário presente nos méis de eucalipto e aroeira, e o ácido p-cumárico nos méis de uva japão. Por fim, as propriedades físico-químicas e biologicamente ativas dos méis foram influenciadas pela origem floral. / Honey is a sweet food made by bees from the nectar of flowers. Previous studies consider honey as a natural sweetener, source of antioxidant compounds that when included in the diet become allies against oxidative damage. However, honey composition is variable because it depends on the floral source, environmental conditions where it is produced and how it is collected and processed. The southern region is different from other Brazilian regions because of its climate and vegetation. In addition, the sum of the main states of the South is 49% of the country\'s honey production, and Rio Grande do Sul (RS) state is the biggest producer. A recent study showed that another product of the hive, bee pollen, derived from this region showed higher concentrations of antioxidant compounds when compared to other regions of the country, encouraging researches for honeys with possible beneficial health effects. In this sense, this study aims to characterize Apis mellifera honey produced in the state of RS, as the physicochemical and antioxidants properties, and establish correlations with the botanical origin. For this, 52 samples were obtained, collected from Honey House, in Viamão, RS, of various botanical origins and different parts of the state. The physicochemical properties evaluated were: melissopalinological analysis, moisture, ash, electrical conductivity, pH and free acidity, colour, diastase activity, sugars, hydroxymethylfurfural (HMF), and Fiehe and Lund reactions, according to the analytical standards established by the Brazilian and international recomendations. The evaluation of antioxidant properties consisted in the identification and quantification of the phenolic compounds by high-performance liquid chromatography; determining the reducing capacity of the Folin-Ciocalteu; determination of total flavonoid; ability to absorb oxygen radical (ORAC); determining the reducing power of iron (FRAP); and DPPH radical scavenging method. The results for the physicochemical analysis characterized the honeys in: monofloral (eucalyptus, mastic, quitoco, Japan grapes, field flower and orange) and heterofloral; the average to moisture was 18.3±0.7 % (max. 20%); the average of ashes was 0.3±0.2 % (max. 0.6%); the electrical conductivity was 0.59±0.2 mS.cm-1 (max. 0.8); the result to pH was 4.18±0.3 and free acidity was 32±9.8 mEq.Kg-1 (max. 50); the colour varied to extra white to amber; the average of diastase activity was 16.4±11.0 °Gothe (min. 8); the average of glucose and fructose determination were, respectively, 37.9±1.4 and 32±2.5 g.100-1; the ratio fructose/glucose was 1.2±0.1; the average content of HMF was 5.6±5.8 mg.Kg-1 (max. 60); and the Fiehe and Lund reactions presented, respectively, negative and positive results to all samples, indicating the purity of honeys analyzed. Regarding the analysis of antioxidants, gallic acid, cinnamic acid and p-coumaric acid, and flavonoids quercetin and myricetin, were identified. Flavonoid and phenolic total content were 61.3±18.3 mgEAG.Kg-1 and 0.7±0.7 mgQE.100g-1, respectively. ORAC antioxidant capacity was 7.8±4.3 mmolET.Kg-1; FRAP was 1.2±0.6 &#181;molET.g-1; and DPPH assay (EC50) was 72.4±89.8 mg.ml-1. Analyzed honeys presented all physicochemical parameters in accordance to honey quality control from Brazilian and international recommendations. The antioxidant capacity was similar to data from scientific literature. The botanical species with the highest antioxidant activity were eucalyptus and mastic. Total phenolic content showed no statistical difference between these two types of honeys, however flavonoid content of mastic honeys was higher (p<0.05) than eucalyptus honeys. Gallic acid was the major compound present in eucalyptus and mastic honeys, and p-coumaric acid in Japan grape honeys. Finally, physicochemical and biologically active properties honeys were influenced by honey floral source.

Polymers with mucoadhesive properties are universally used in the development of mucoadhesive drug delivery system. Their physicochemical properties as well as the mechanisms related to their adhesive actions draw great attention for the modification of mucoadhesive properties. In this study, relationships between physicochemical properties of hydroxypropyl methylcellulose (HPMC) compacts and mucoadhesive performance were investigated. Different commercial grades of HPMC (K3, E3, E5, E50, K4M, E4M and K15M) were prepared into compacts, and their surface hydrophilicity and hydration behavior were characterized. The in vitro mucoadhesive performance was determined by the tension strength between the compacts and different regions of mucous membrane (buccal, sublingual, stomach, and intestine). Positive correlations were found between: (1) viscosity of HPMC compacts and contact angle values measured by different simulated body fluids; (2) viscosity of HPMC compacts and in vitro mucoadhesive force; (3) contact angle values and in vitro mucoadhesive force. The hydration behavior exhibited improvement with the increasing viscosity of HPMC compacts. Moreover, the polar lipid content of each mucosa was likely an important factor affecting the mucoadhesion phenomenon. Different ratios of ethyl cellulose (EC) was mixed with HPMC grade K15M to form combination compacts for the purpose of modifying the surface property. The mucoadhesive mechanism of both different grades of HPMC compacts and combination compacts were studied via the thermodynamic analysis of Lifshiz-van der Waals interaction and Lewis acid-base interaction. The total free energy of adhesion (〖∆G〗^TOT) provided a prediction of an overall tendency of mucoadhesion, however, the results were showing disagreement with the measured mucoadhesive force. In general, the involving of EC in the combination compacts did not give a boost to the whole mucoadhesive performance.

No description available.

The presence of postharvest sanitizers has shown to be an effective approach to reducing microbial cross contamination in agricultural washing operations. However, choosing an appropriate sanitizer can be challenging due to produce commodity, processing conditions and interference with organic load. Current research shows a wide variety of methods to mimic the organic load of vegetable processing conditions, with paddle mixing and blender as the most commonly used. Controlling and understanding the physiochemical properties of wash water is key in maintaining sanitizer efficacy. The effects of simulated wash water preparation method on the physiochemical properties were tested at 0 and 50 COD(mg/L) and no significant difference was observed. However, at high levels of organic load results showed a significant difference between turbidity values at 1,500 COD. Free residual chlorine titration methods were compared, using DPD-titrimetric and Iodometric method. Results showed a significant difference between titration methods in organic load heavy environments. Commercially available chlorine based sanitizers, Pure Bright™ Germicidal Bleach and Clorox® Germicidal Bleach, were compared to a concentrated solution of sodium hypochlorite. Pure Bright™ Germicidal Bleach showed to perform the best by reducing 7 log CFU/ml of E. coli O157:H7 after 30 seconds in no organic load environments, whereas Clorox Germicidal bleach was able to reduce 7 log CFU/ml of E. coli O157:H7 after 30 minutes. These studies aim to provide best management practices for small in medium growers in the implementation of antimicrobial solutions for the maintenance of water quality in postharvest washing solutions.

Ce travail est consacré au développement d’un couplage méthodologique entre la méthode d’Analyse de Cycle de Vie (ACV) et un logiciel de génie de procédés (Aspen Plus), en vue d’améliorer la qualité des données de l’Inventaire du Cycle de Vie (LCV) de la filière classique de production d’acier. La nouvelle approche développée est destinée à la réalisation de l’inventaire pour un système défini à partir de modèles physico-chimiques simplifiés. Ainsi, à l’aide du logiciel Aspen Plus, nous avons mis en oeuvre la modélisation de chaque sous-système considéré dans les frontières de la filière classique de production d’acier : cokerie, agglomération, haut fourneau, convertisseur et laminoir à chaud. L’approche de modélisation adoptée a été basée sur des considérations physiques et chimiques et sur des observations expérimentales à l’échelle industrielle et/ou à l’échelle pilote pour chaque sous-système. Les modèles permettent le calcul de la plupart des émissions engendrées par le système : CO2, CO, NO, SO2, COV, HCl, H2S, poussières et métaux lourds ainsi que des déchets. La validation des modèles a été faite par comparaison des résultats calculés avec des mesures expérimentales disponibles pour des sites industriels. De plus, le comportement des modèles a été testé en réalisant des simulations en utilisant une base de données "de référence" définie dans le cadre du projet européen ULCOS (Ultra Low CO2 Steelmaking). Il est montré que cette approche méthodologique assure le contrôle total du bouclage des bilans de matière et d’énergie du système, difficile à réaliser à partir des données provenant exclusivement de mesures industrielles et/ou de la littérature. De plus, le fait que les émissions soient calculées sur des considérations physicochimiques, conduit à donner une forte crédibilité à l’inventaire réalisé / This work was devoted to a new methodological framework, which combines the Life Cycle Assessment (LCA) method and the process simulation software (Aspen Plus), in order to improve the quality of data used for carrying out the Life Cycle Inventory (LCI) of the classical steelmaking route. The new approach adopted in the present work, is to carry out the inventory of the defined system via simplified physical-chemical models. Using Aspen Plus software, we have developed simplified physical-chemical models for each of the subsystem defined by the boundaries of the classical steelmaking route: coking plant, sintering plant, blast furnace, basic oxygen furnace and hot rolling. The modelling strategy was based on physical and chemical considerations and on the experimental observations made on an industrial and/or a pilot scale for each subsystem.The models allow for calculation of the principal pollutants evolved by the system such as CO2, CO, NO, SO2, COV, HCl, H2S, dust, heavy metals and solid waste. The models validation was made by comparing the calculated results with experimental data given by the industrial sites. Furthermore, the maturity of the models was tested through simulations using data coming from the "benchmark" data base defined in the frame of ULCOS project (Ultra Low CO2 Steelmaking).Through the models simulation, it was proved that this methodological framework assures the total control of mass and heat balances of the system which is difficult to achieve when using only data from industry and/or literature. However, the fact that the emissions calculated within the models are based on physical-chemical considerations gives a strong credibility to the life cycle inventory

Une étude comparative des caractéristiques statiques, dynamiques et structurale a été menée sur 8 membranes échangeuses d'ions (MEIs), 4 neuves (MEIN) et les mêmes usagées (MEIU) après 2 ans de fonctionnement en ED dans l'industrie agroalimentaire. L'objectif essentiel était de mieux connaître les mécanismes de vieillissement in situ. Nous avons donc mesuré pour chacune de ces MEIs la capacité d'échange, la teneur en eau, la perméabilité ionique, la conductivité électrique, le nombre de transport, l'angle de contact, le courant limite, le module d'Young et la résistance à la traction. Aussi, nous avons effectué des analyses d'IRTF, de MEB et d'EDX. Cette étude nous a permis de conclure que (i) la MEC2 est restée presque stable après les 2 ans d'ED, alors que la MEA1 s'est très fortement dégradée. D'une manière générale, les MEAs sont plus sensibles au vieillissement que les MECs, (ii) les sites fonctionnels sulfoniques s'éliminent de la MEC. Nous ne pouvons pas affirmer ce mécanisme dans le cas des MEAs, mais nous soupçonnons un phénomène d'empoisonnement des sites fonctionnels, (iii) les MEAs se colmatent en surfaces avec des ampleurs différentes entre la MEA1 et la MEA2 / A comparative study of static characteristics, dynamic and structural was conducted on 8 ion-exchange membranes (MEIS), 4 new (IEMN) and the same used (IEMU) after two years of ED operation in the food industry. The main objective was to better understand the mechanisms of in situ ageing. We therefore measured for each IEMs exchange capacity, water content, ionic permeability, electrical conductivity, transport number, contact angle, current limit, Young's modulus and tensile strength. Therefore, we performed analysis of FTIR, SEM and EDX. This study concluded that (i) CEM2 remained almost stable after 2 years of ED, while AEM1 has sharply deteriorated. In general, the AEMs are more susceptible to ageing than CEMs, (ii) the sulfonic functional sites are eliminated from the CEMs. We cannot confirm this mechanism in the case of AEMs, but we suspect a poisoning phenomenon of functional sites, (iii) the AEMs fouled in surfaces with different degrees between AEM1 and AEM2