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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Contribution à l'élaboration d'un modèle d'évolution physico-chimique de la neige

Bock, Josue 02 May 2012 (has links) (PDF)
Il est aujourd'hui avéré que la composition chimique de l'atmosphère des régions enneigées - et notamment des régions polaires - est sensiblement affectée par les échanges d'espèces chimiques réactives entre l'air et la neige. En effet, le manteau neigeux constitue un véritable réacteur photochimique multiphasique, mais les mécanismes physico-chimiques à l'œuvre en son sein sont encore mal connus. Une compréhension détaillée des processus s'y déroulant est indispensable pour modéliser correctement la composition et la réactivité de l'atmosphère au-dessus des régions enneigées. De plus, la reconstitution de l'évolution post-dépôt des composés chimiques stables de la neige est également un préalable indispensable pour permettre l'interprétation paléoclimatique de leurs profils de concentration enregistrés dans les carottes de glace.Le nitrate (NO3-) présent dans la neige joue un rôle fondamental, car sa photolyse induit notamment l'émission d'oxydes d'azote (NOx = NO + NO2) par le manteau neigeux, qui modifient la capacité oxydante de l'atmosphère via la production d'ozone. L'objet de cette thèse a donc été d'étudier par modélisations les processus physico-chimiques intervenants dans l'évolution de la concentration du nitrate dans la neige.Une première approche, prolongeant des études préexistantes, a visé à identifier un mécanisme réactionnel pour la photochimie du nitrate dans la neige, en postulant notamment l'existence d'une couche quasi-liquide à la surface des grains de neige. Néanmoins, les propriétés exactes de l'interface air - glace sont, à l'heure actuelle, encore mal caractérisées, et il est apparu que cette démarche présentait de trop larges incertitudes pour être poursuivie.Une discussion approfondie a alors été menée afin d'évaluer les tentatives actuelles de modélisation de la chimie de la neige, et dans le but de proposer une nouvelle approche plus réaliste au regard du niveau de connaissance actuel.Ainsi, dans une seconde partie, l'ensemble des processus d'échange physico-chimiques du nitrate entre l'air et la neige ont été étudiés puis modélisés : adsorption à la surface, diffusion en phase solide et co-condensation. Parmi les résultats obtenus, il est apparu que les paramétrisations actuelles de la couverture surfacique en nitrate étaient incapables de reproduire les concentrations mesurées, dans le cas de la neige de surface à Dome C, et révèlent d'importantes surestimations. A contratio, la prise en compte conjointe de la diffusion en phase solide ainsi que d'un processus de co-condensation permet de bien reproduire qualitativement les séries temporelles de plus d'un an, couvrant donc à la fois l'été et l'hiver austral, qui présentent chacun des caractéristiques distinctes en terme de concentration mesurées.Cette étude révèle ainsi l'importance de ces processus physico-chimiques d'échange dans la modélisation de la chimie de la neige, et pose les bases des mécanismes à prendre en compte dans le cadre de développements futurs.
302

Nouvelles approches pour la nano-caractérisation, et la micro- et nano-robotique par sondes locales

Polesel, Jérôme 02 October 2012 (has links) (PDF)
Le développement de la microscopie à effet tunnel (Scanning Tunneling Microscopy, STM), et ensuite de la microscopie à force atomique (Atomic Force Microscopy, AFM), dans les années 80 a représenté la percée la plus significative des nanosciences, sinon leur vrai point de départ. Depuis 1991, la microscopie de force AFM a été exploitée avec succès pour l'étude du monde biologique. La polyvalence de l'instrument a permis l'étude de différents objets biologiques de la protéine isolée aux tissus de cellules dans leur environnement de survie. Récemment, un intérêt croissant est né pour une transition de sondes locales micrométriques vers des sondes nanométriques pour augmenter les taux d'acquisition de données, améliorer la résolution de détection en force et ouvrir la voie à des caractérisations à très haute vitesse. Certaines de ces problématiques de vitesse ont été partiellement résolues avec l'arrivée d'un certain nombre de prototypes de microscope AFM "Ultra-Rapides", mais au détriment d'un faible nombre de pixels et d'une excursion spatiale limitée (< 1 micron) du scanner de balayage. De plus, ces techniques nécessitent l'utilisation de microleviers AFM plus petits que la dizaine de microns pour conserver une haute sensibilité de détection en force avec de hautes fréquences de fonctionnement de l'ordre du megaHertz ou plus. Ainsi, la détection optique conventionnelle par faisceau arrive aujourd'hui à ses limites pour implémenter des sondes dont les dimensions ne sont que de l'ordre de quelques longueurs d'onde. De nouvelles méthodes de détection du mouvement de la sonde AFM, ou même de nouveaux types de sondes AFM doivent donc être mis en œuvre et optimisés pour la prochaine génération d'instruments à sonde locale. Dans ce contexte, un panorama de travaux apportant des réponses à ces nouvelles problématiques de caractérisation, de manipulation, et de fabrication aux échelles micro- et nanométriques aux moyens de nouveaux instruments à sondes locales sera exposé dans ce manuscrit.
303

Cristallochimie et propriétés physiques des borates magnésiens des skarns de la province banatitique de Roumanie

Marincea, Stephan 15 June 1998 (has links) (PDF)
L'étude apporte des nouvelles données sur les borates magnésiens de cinq gites de skarns de Roumanie : Baita Bihor, Pietroasa, Ocna de Fier, Masca-Baisoara et Cacova Ierii. Les aires de skarn sont developpées autour des intrusions calco-alcalines d'âge crétacé supérieur - paléogène, connues sous le nom collectif de banatites. Les borates qui ont été identifiés, à savoir la ludwigite, la kotoite, la szaibelyite, la suanite et la fluoborite sont caractéristiques d'une association géochimique très connue, Mg-B-OFe. Les minéraux de chaque occurrence ont été minutieusement analysés en utilisant la diffractométrie des rayons X sur poudres, l'absorption infrarouge, l'étude thermique, l'analyse chimique par voie humide et à la microsonde électronique. On peut distinguer deux types d'associations géochimiques : l'une riche en fer, à Ocna de Fier, Cacova Ierii, Masca-Baisoara et l'autre déficitaire en cet élément, à Baita Bihor et Pietroasa. La cristallisation des borates a eu lieu à des températures comprises entre 300°C et 650°C pour des pressions comprises entre 0,6 et 3 kB. Toutes les espèces sont remarquablement homogènes du point de vue chimique et optique et extrêmement riches en magnésium. La ludwigite montre un comportement superparamagnétique et un puissant effet d'anisotropie magnétique de forme. Elle est inerte thermiquement jusqu'à 1000°C. Une ludwigite alumineuse a été identifiée à Pietroasa et une kotoite ferreuse à Cacova Ierii. L'occurrence de la fluoborite est restreinte aux associations riches en fluor et bore de Baita Bihor, tandis que la suanite préfère les systèmes pauvres en fer de Baita Bihor et Pietroasa. Fe<sup>2+</sup> est le principal substituant du magnésium dans toutes les espèces de borates analysées. La szaibelyite renferme usuellement des faibles teneurs en fluor et sa maille élémentaire comporte deux vibrateurs hydroxyles. La déshydratation thermique de la szaibelyite se produit à 650-670°C, quand elle passe en Mg<sub>2</sub>B<sub>2</sub>O<sub>5</sub> monoclinique.
304

Le nettoyage : une étape-clef pour une production durable par procédé à membrane : réflexion sur le lien entre conditions de production et nettoyabilité d'une membrane PES de l'industrie laitière

Diagne, Ndeye Wemsy 12 December 2013 (has links) (PDF)
Le nettoyage en place des membranes en industrie agro-alimentaire est une opération cruciale qui, outre les exigences de sécurité sanitaire des installations et des produits traités doit permettre de restaurer les performances de la filtration (sélectivité, flux) en éliminant le colmatage formé pendant l'étape de production. Malheureusement cette étape repose encore sur des bases empiriques et non optimisées. A cause d'un manque de notions fondamentales, elle est encore pressentie comme un frein à l'utilisation massive des procédés membranaires. Une démarche originale a été menée dans le cadre de cette thèse incluant la réflexion sur l'incidence des paramètres hydrodynamiques des conditions de production sur la cohésion du dépôt colmatant et plus particulièrement de sa fraction irréversible, dont la nettoyabilité est étudiée. Pour fonder cette démarche, une étude comparée du colmatage et du nettoyage au flux limite et au flux critique a été réalisée en intégrant le rôle de la physico-chimie et de l'hydrodynamique pendant la phase de production. cette étude s'inscrit dans un cadre d'éco-conception de procédé, avec une analyse de cycle de vie réalisée afin d'estimer l'impact environnemental de l'étape de nettoyage via divers scénarii simplifiés.
305

Assessment of the physico-chemical and microbiological quality of household water in the Vaalharts irrigation scheme, South Africa / G. O'Reilly.

O'Reilly, Guzene January 2012 (has links)
Water quality in the Vaalharts region in the Northern Cape Province, South Africa, decreased over the past few years and there was a need for the microbiological and physico-chemical assessment. This problem was identified through discussions with Vaalharts Water (Vaalharts Water User Association) in 2010 when the issue of the impact of deteriorating water quality on drinking water production was raised. It was thus important to investigate concerns of the water users association pertaining to water quality issues. The aim of this study was to assess the physico-chemical and microbiological quality of household water in the Vaalharts irrigation scheme. The main residential areas were Hartswater, Pampierstad, Jan Kempdorp and Warrenton. Faecal coliforms were detected in the raw water of all the drinking water distribution systems during 2011 and 2012. No faecal coliforms were detected in the household water during 2011. This was a very positive result, because not only did the household water comply with the SANS 241 (2011) standard (0 CFU/100ml), but the purification processes were successful by removing all the E. coli’s from the raw water. However, during March 2012 faecal coliforms were detected in the household water of Jan Kempdorp (191CFU/100ml). This could be due to point pollution and possible breakage of faecal coliforms in the distribution system. Low amounts of total coliforms were detected in the raw water of some of the drinking water distribution systems. This could be due to high amounts of other colonies (pink and purple) growing on the m-Endo agar which suppress the growth of the metallic green sheen (total coliform) colonies. The total coliform numbers complied with the SANS 241 (2011) standard of ≤10 CFU/100ml at most of the distribution systems, except for Hartswater during July 2011 (14CFU/100ml) and Warrenton during March 2012 (256 CFU/100ml). Heterotrophic plate count bacteria were very high in the household water of some of the distribution systems during 2011 and 2012 which exceeded the SANS 241 (2011) standard of ≤1000 CFU/ml. A large number of pigmented (yellow, orange, pink) and non-pigmented (white) colonies were isolated on R2A agar. This can be an indication of some failure in treatment processes. Other microbiological parameters that were tested such as faceal streptococci, Clostridia, Pseudomonas aeruginosa and fungi did not indicate any danger, but there were high levels of total anaerobic bacteria in the raw water during 2011 and 2012. A high level of anaerobic bacteria was detected in the household water of Hartswater during July 2011. Clostridia were also present in the household water of some of the distribution systems during 2011 and 2012. Sequencing results of the mdh, lacZ and uidA genes indicated that one of the isolates was identified as Enterobacter cloacae and the other isolates were E. coli. Four of the isolates were identified as Escherichia coli O104:H4. This is a pathogenic strain and raised concern. The physicochemical parameters that were measured complied with the SANS 241 (2011) standards during 2011 and 2012, but some of the parameters increased gradually from 2011 to 2012. Statistical analysis indicated that physico-chemical parameters had an influence on microbiological parameters and that deteriorating raw water may have an impact on drinking water quality. Another concern currently is that there is no SANS 241 (2011) for faecal streptococci, Clostridia, Pseudomonas aeruginosa, fungi and anaerobic bacteria. These are all opportunistic pathogenic bacteria and consuming water with high levels of these bacteria may cause health problems. This study indicated good progress in the treatment processes of the distribution systems over the two years. This may be due to the feedback given to Vaalharts Water during this study regarding the water quality of the residential areas. The physico-chemical and microbiological results of the present study indicated possible biofilm formation in the distribution systems. This may have impacts on the drinking water quality of the distribution systems. It was also evident that deteriorating raw water sources may have an impact on drinking water production. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.
306

Assessment of the physico-chemical and microbiological quality of household water in the Vaalharts irrigation scheme, South Africa / G. O'Reilly.

O'Reilly, Guzene January 2012 (has links)
Water quality in the Vaalharts region in the Northern Cape Province, South Africa, decreased over the past few years and there was a need for the microbiological and physico-chemical assessment. This problem was identified through discussions with Vaalharts Water (Vaalharts Water User Association) in 2010 when the issue of the impact of deteriorating water quality on drinking water production was raised. It was thus important to investigate concerns of the water users association pertaining to water quality issues. The aim of this study was to assess the physico-chemical and microbiological quality of household water in the Vaalharts irrigation scheme. The main residential areas were Hartswater, Pampierstad, Jan Kempdorp and Warrenton. Faecal coliforms were detected in the raw water of all the drinking water distribution systems during 2011 and 2012. No faecal coliforms were detected in the household water during 2011. This was a very positive result, because not only did the household water comply with the SANS 241 (2011) standard (0 CFU/100ml), but the purification processes were successful by removing all the E. coli’s from the raw water. However, during March 2012 faecal coliforms were detected in the household water of Jan Kempdorp (191CFU/100ml). This could be due to point pollution and possible breakage of faecal coliforms in the distribution system. Low amounts of total coliforms were detected in the raw water of some of the drinking water distribution systems. This could be due to high amounts of other colonies (pink and purple) growing on the m-Endo agar which suppress the growth of the metallic green sheen (total coliform) colonies. The total coliform numbers complied with the SANS 241 (2011) standard of ≤10 CFU/100ml at most of the distribution systems, except for Hartswater during July 2011 (14CFU/100ml) and Warrenton during March 2012 (256 CFU/100ml). Heterotrophic plate count bacteria were very high in the household water of some of the distribution systems during 2011 and 2012 which exceeded the SANS 241 (2011) standard of ≤1000 CFU/ml. A large number of pigmented (yellow, orange, pink) and non-pigmented (white) colonies were isolated on R2A agar. This can be an indication of some failure in treatment processes. Other microbiological parameters that were tested such as faceal streptococci, Clostridia, Pseudomonas aeruginosa and fungi did not indicate any danger, but there were high levels of total anaerobic bacteria in the raw water during 2011 and 2012. A high level of anaerobic bacteria was detected in the household water of Hartswater during July 2011. Clostridia were also present in the household water of some of the distribution systems during 2011 and 2012. Sequencing results of the mdh, lacZ and uidA genes indicated that one of the isolates was identified as Enterobacter cloacae and the other isolates were E. coli. Four of the isolates were identified as Escherichia coli O104:H4. This is a pathogenic strain and raised concern. The physicochemical parameters that were measured complied with the SANS 241 (2011) standards during 2011 and 2012, but some of the parameters increased gradually from 2011 to 2012. Statistical analysis indicated that physico-chemical parameters had an influence on microbiological parameters and that deteriorating raw water may have an impact on drinking water quality. Another concern currently is that there is no SANS 241 (2011) for faecal streptococci, Clostridia, Pseudomonas aeruginosa, fungi and anaerobic bacteria. These are all opportunistic pathogenic bacteria and consuming water with high levels of these bacteria may cause health problems. This study indicated good progress in the treatment processes of the distribution systems over the two years. This may be due to the feedback given to Vaalharts Water during this study regarding the water quality of the residential areas. The physico-chemical and microbiological results of the present study indicated possible biofilm formation in the distribution systems. This may have impacts on the drinking water quality of the distribution systems. It was also evident that deteriorating raw water sources may have an impact on drinking water production. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.
307

Liofilização como método de agregar valor ao camarão marinho litopenaeus vannamei

Rocha, Maria Margareth Rolim Martins 25 November 2010 (has links)
Made available in DSpace on 2015-04-17T14:49:45Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2168276 bytes, checksum: 5dbc05dbbef9f8d6f7a4c240e8bc725c (MD5) Previous issue date: 2010-11-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The marine shrimp Litopenaeus vannamei is a worldwide cultivated species, which is responsible for almost all the production of marine aquaculture in Brazil. Besides having a high nutritional value, it is also appreciated by consumers and there is the possibility of elaborating value-added products. The aim of this study is to evaluate the quality of the marine shrimp Litopenaeus vannamei in its lyophilizated form, using samples without pre-cooking and pre-cooked ones, and adding to them the tri and polyphospates and EDTA adictives. Experiences were made in order to determin the most adequate form of the shrimps rehydration and the physico-chemical analysis gathering centesimal composition, water activity, colour, water retention capacity, cholesterol level precision, fatty acids, aminoacids, vitamins, minerals, besides the caloric value, microbiological analysis and sensorial analysis. Lyophilization is a drying process in which the water passes from the solid to the vapor state, without going through the liquid state, leading to a decrease of the water activity and the food can be kept in room temperature. In this study, the rehydration was achieved in 2.5 minutes. The results showed that the Lyophilization process did not cause significant differences for water activity, pH and gain of weight in the rehydration. There has been a significantly different number for CRA in the TPF 5%-PC-L (99.99%). Lipids, proteins and ashes presented numbers with significant difference.The pré-cooked shrimps showed greater intensity of colour (62,05 to 71,06 for the angle a* and 19,22 to 32,59 for the angle b*). Phosphorus and Calcium presented figures between 189,06 and 301, 22 mg/100g. Cholesterol varied from 70,06 to 78,44 mg/100g. Fatty Acids with larger incidence were the mono and poliinsaturated. The aminoacids showed significant oscilations. The result of the sensorial analysis showed that the marine shrimp Litopenaeus vannamei lyophilizated is a product with a added value of great acceptation according to the consumers test. / O camarão marinho Litpenaeus vannamei é uma espécie cultivada em todo mundo, sendo responsável por quase toda produção da aquicultura marinha do Brasil. Além de ser um alimento de alto valor nutricional é bastante apreciado pelos consumidores podem ser elaborados produtos com valor agregado. Nesse contexto, de forma a avaliar a qualidade do camarão marinho, Litopenaeus vannamei, foram elaborados produtos sob a forma liofilizada utilizando-se amostras sem pre cozimento e pre cozidas, adicionadas dos aditivos tripolifosfato de sódio e EDTA. Foram realizados ensaios para a determinar a forma mais adequada da reidratação dos camarões e as análises físico-químicas envolvendo composição centesimal, atividade de água, cor, capacidade de retenção de água, determinação do teor de colesterol, ácidos graxos, aminoácidos, vitaminas, minerais, além do valor calórico, análises microbiológicas e analise sensorial. A liofilização, é um processo de secagem onde a água passa do estado sólido para o de vapor, sem passar pelo estado líquido, ocasionando uma redução da atividade de água e o alimento pode ser conservado em temperatura ambiente. No presente estudo a reidratação foi obtida em 2,5 minutos. Os resultados mostraram que o processo de liofilização não causou diferenças significativas para atividade de água, pH e ganho de peso na reidratação. Houve um valor significativamente diferente para CRA no TPF 5%-PC-L (99.99%). Lipídios, proteínas e cinzas apresentaram valores com diferença significativa. Os camarões pré cozidos apresentaram maior intensidade de cor (62,05 a 71,06 para o ângulo a* e 19,22 a 32,59 para o ângulo b*). Fósforo e Cálcio apresentaram valores entre 189,06 a 301, 22 mg/100g. Colesterol variou de 70,06 a 78,44 mg/100g. Os ácidos graxos com maior incidência foram os mono e poliinsaturados. Os aminoácidos apresentaram variações significativas. O resultado da análise sensorial mostrou que o camarão marinho Litopenaeus vannamei é um produto com valor agregado de grande aceitação pelo teste dos consumidores.
308

Estudo sobre as potencialidades de comp?sitos ? base de gesso e fibras de coco seco para aplica??o na constru??o civil

Cunha, Paulo Waldemiro Soares 28 December 2012 (has links)
Made available in DSpace on 2014-12-17T14:07:19Z (GMT). No. of bitstreams: 1 PauloWSC_TESE.pdf: 3368472 bytes, checksum: 6f9f6907ea0f81a6a00e41d776e566c5 (MD5) Previous issue date: 2012-12-28 / The use of gypsum, one of the oldest building materials for the construction industry in the country has been experiencing a significant and steady growth, due to its low cost and some of its properties that confer comparative advantage over other binder materials. Its use comprises various applications including the coating of walls and the production of internal seals and linings. Moreover, the fibers are being increasingly incorporated into arrays fragile in an attempt to improve the properties of the composite by reducing the number of cracks, the opening of the same and its propagation velocity. Other properties, depending on the function of the component material or construction, among these thermal and acoustic performances, are of great importance in the context of buildings and could be improved, that is, having better performance with this embodiment. Conduct a comparative study of physico-mechanical, thermal and acoustic composite gypsum incorporating dry coconut fiber, in the form of blanket, constituted the main objective of this work. Improving the thermal and acoustic performances of precast gypsum, used for lining and internal vertical fences of buildings, was the purpose of development of these composites. To evaluate the effect of fiber content on the properties of the composites were used to manufacture the composite layer with different thicknesses. The composites were fabricated in the form of plates with dimensions of 500x500x24mm. To facilitate the comparative study of the properties were also made with material gypsum boards only. We then determined the physico-mechanical, thermal and acoustical plaster and composites. The results indicated that the composites were significant gains in relation to thermal performance and also acoustic, in certain frequency range, increasing the thickness of the blanket. Concerning other physical-mechanical properties, the results showed that although the compressive strength was lower than for the composite did not occur after a fracture catastrophic failure. The same trend was observed with regard to resistance to bending, since the composites have not suffered sudden rupture and still continued after the load supporting point of maximum load / A utiliza??o do gesso, um dos mais antigos materiais de constru??o, pela ind?stria da constru??o civil no Pa?s, vem experimentando um sens?vel e constante crescimento, em fun??o do seu baixo custo e de algumas de suas propriedades que lhe conferem vantagem comparativa em rela??o a outros materiais ligantes. Sua utiliza??o compreende diversas aplica??es entre as quais o revestimento de paredes e a confec??o de veda??es internas e de forros. Por outro lado, as fibras v?m sendo, cada vez mais, incorporadas em matrizes fr?geis, na tentativa de melhorar as propriedades do comp?sito, atrav?s da redu??o do n?mero de fissuras, da abertura das mesmas e da sua velocidade de propaga??o. Dependendo da fun??o do material ou do componente da constru??o, os desempenhos t?rmico e ac?stico, assumem grande import?ncia no contexto das edifica??es e tamb?m poderiam ser melhoradoscom a incorpora??o de fibras. Dentre as fibras vegetais, a fibra de coco seco apresenta um grande potencial, superior ?s vantagens comparativas das demais fibras, tal como uma maior resist?nciafrente ? alcalinidade caracter?stica das matrizes ciment?cias. Realizar um estudo comparativo das propriedades f?sico-mec?nicas, t?rmicas e ac?sticas de comp?sitos ? base de gesso com incorpora??o de fibra de coco seco, sob a forma de manta, constituiu-se no objetivo geral deste trabalho. Para tanto os materiais comp?sitos foram confeccionados em forma de placas, pain?is sandu?ches, com dimens?es de 500x500x24mm, sendo as camadas externas constitu?das pelogesso e a central (recheio) pela manta de fibra de coco seco. Para avaliar a influ?ncia do teor de fibras nas propriedades dos comp?sitos foram utilizadas na confec??o dos mesmos mantas com espessuras de 8 e 10 mm. Para possibilitar o estudo comparativo das propriedades foram tamb?m confeccionadas placas apenas com gesso. Foram ent?o determinadas as propriedades f?sico-mec?nicas, t?rmicas e ac?sticas do gesso e dos comp?sitos. Os resultados indicaram que para os comp?sitos ocorreram ganhos significativos em rela??o aos desempenhos t?rmico e tamb?m ac?stico, na faixa de frequ?ncia de 102,28 Hz a 1.150,00 Hz, ganhos esses crescentes com a espessura da manta. Em rela??o ?s demais propriedades f?sico-mec?nicas, os resultados mostraram que embora a resist?ncia ? compress?o tenha sido inferior para os comp?sitos, as fibras apenas evitaram um rompimento brusco, uma vez que as mesmas n?o atuam como refor?o para esse tipo de solicita??o. O mesmo comportamento ocorreu em rela??o ? resist?ncia ? flex?o, uma vez que os comp?sitos n?o sofreram ruptura brusca e ainda continuaram suportando carga depois do ponto de carga m?xima
309

Pólen apícola do estado de Alagoas : composição físico-química, origem botânica e atividade antioxidante. / Bee pollen of Alagoas State : physico-chemical composition, botanical origin and antioxidant activity.

Vasconcelos, Maria Raphaella dos Santos 29 April 2009 (has links)
Beekeeping is an activity known worldwide. In Brazil, it has found favorable conditions for its establishment. In the State of Alagoas, where it is still a practicing of beekeeping craft, require official data on the quality of their products to become more professional. Among the bee products, bee pollen resulting from the agglutination of flower pollen and nectar with salivary substances, emerge as food for worker-bees, with therapeutic properties given its composition. It is rich in protein, carbohydrates, lipids, minerals and vitamins, phenols and growth factors. In apiaries, bee pollen is the main source of food and protection for the larvae of bees. As human food, it requires for marketing monitoring of its physico-chemical and microbiological quality, with limits established by the health legislation. In this work, it was assessed the floral origin and the physico-chemical, and possible antioxidant and antimicrobial activity, of bee pollen from three experimental apiaries representative of the mesoregions of Zona da Mata , Backlands and Seaside of Alagoas State, in the dry season of 2008/09. Physico-chemical data were submitted to tests of normality of Kolmogorov-Smirnov and Shapiro-Wilk, and then the non-parametric test of Kruskal-Wallis. The pollen spectrum was more abundant in the Zona da Mata region, where 28 plant species were represented in the bee pollen - 36% of the herbaceous layer and 64% of shrub and tree strata. In the bee pollen of the Seaside and Backlands predominated, respectively, tree and shrub strata, with sampling generally monofloral in the Backlands. The total contents of protein, glucose and lipids were measured respectively by the methods of Lowry, Antrona and Bligh & Dyer. The levels of total carbohydrates did not differ significantly between the bee pollen of the different mesoregions studied. The average content of total lipids and phenols in the bee pollen of the Backlands were the largest among the three mesoregions (respectively, 4.92-7.74% and 16.22- 46.25 eq. mg Ac. Galic.g-1). The total content of flavonoids varied considerably, but was higher in samples of Backlands (45.62 ± 32.19 eq. quercetine.g mg-1), although near the sampling of the Zona da Mata (41.22 ± 21.95 eq. quercetine.g mg-1). The antioxidant potential of samples of bee pollen of Backlands was much higher than that of other samples of other mesoregions, ranging from 53.22 to 250.19 eq. mg ac. galic.g-1. The samples of bee pollen from the Seaside were the ones that showed higher protein content (1.21-3.32 eq. mg BSA.mL-1) and lower antioxidant content (10.0-103.22 eq. mg ac. galic.g-1), although in the qualitative point of view all the samples had similar flanonoid substances. The tested did not show activity against the microorganisms Staphylococcus aureus, Salmonella Typhimurium, Escherichia coli, Helicobacter pylori concentrations of the extracts of bee pollen of the dry season (2008/09) from all mesoregions studied. / Fundação de Amparo a Pesquisa do Estado de Alagoas / A apicultura é uma atividade mundialmente conhecida e, no Brasil, tem encontrado condições climáticas favoráveis para seu estabelecimento. Configura-se neste espaço o Estado de Alagoas, onde ainda é uma prática artesanal que requer dados oficiais sobre a qualidade de seus produtos para se tornar mais profissional. Dentre os seus produtos, o pólen apícola é o resultante da aglutinação do pólen floral com néctar e substâncias salivares das abelhas operárias, e desponta como alimento com propriedades terapêuticas, face à sua composição rica em proteínas, carboidratos, lipídios, sais minerais e vitaminas, além de compostos fenólicos e fatores de crescimento. No apiário, é a principal fonte de alimento e proteção das larvas de abelhas. Como alimento humano, o pólen apícola requer monitoramento de sua qualidade físico-química e microbiológica, segundo limites estabelecidos pela legislação sanitária, para sua comercialização. Neste trabalho, portanto, efetuou-se a avaliação da origem floral e da qualidade físico-química, bem como possível atividade antioxidante e antimicrobiana do pólen apícola de três apiários experimentais de municípios representativos das mesorregiões do Sertão, Zona da Mata e Litoral do Estado de Alagoas, na estação seca de 2008/09. Os dados físico-químicos foram submetidos aos testes de normalidade de Kolmogorov-Smirnov e Shapiro-Wilk e, em seguida, ao teste nãoparamétrico de Kruskal-Wallis. O espectro polínico se mostrou mais abundante na Zona da Mata, sendo identificadas 28 espécies vegetais no pólen apícola dessa região, 36 % do estrato herbáceo e 64 % dos estratos arbustivo e arbóreo. No espectro polínico do Litoral e do Sertão identificaram-se como predominantes respectivamente os estratos arbustivo e arbóreo, sendo a amostragem do Sertão em geral monofloral. Os conteúdos de proteínas, glicídeos e lipídeos totais, foram mensurados respectivamente pelos métodos de Lowry, Antrona e Bligh & Dyer. Os teores de glicídios totais do pólen apícola de distintas mesorregiões não diferiram significativamente entre si. As médias do conteúdo de lipídios e de fenóis totais no pólen apícola do Sertão foram as maiores dentre as três mesorregiões (respectivamente 4,92-7,74 % e 16,22-46,25 eq. mg ác. gálico.g-1). O conteúdo total de flavonóides oscilou bastante, mas também foi superior nas amostras do Sertão (45,62 ± 32,19 eq. mg quercetina.g-1), embora próximo ao das amostragens da Zona da Mata (41,22 ± 21,95 eq. mg quercetina.g-1). O potencial antioxidante das amostras de pólen apícola do Sertão foi bem superior ao das demais amostras, variando de 53,22-250,19 eq. mg ác. gálico.g-1 . As amostras de pólen apícola provenientes do Litoral foram as que apresentaram maior teor em proteínas (1,21-3,32 eq. mg ASB.mL-1) e menor conteúdo antioxidante (10,0-103,22 eq. mg ác. gálico.g-1), embora do ponto de vista qualitativo todas as amostras apresentaram, praticamente, as mesmas substâncias, ainda que em quantidades diferentes. Não se constatou atividade contra os microrganismos Staphylococcus aureus, Salmonella Typhimurium, Escherichia coli, Helicobacter pylori na concentração testada dos extratos de pólen apícola da estação seca (2008/09) de todas as mesorregiões estudadas.
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Elaboração de material de referência in house para vacina contra Hib e produtos intermediários: uma proposta para normalização de testes físico-químicos do controle de qualidade

Rodrigues, Elô de Oliveira January 2009 (has links)
Submitted by Priscila Nascimento (pnascimento@icict.fiocruz.br) on 2012-11-23T15:50:27Z No. of bitstreams: 1 elo-de-oliveira-rodrigues.pdf: 697936 bytes, checksum: fb3899c2c6d659498d8e8ab0a1a0b33a (MD5) / Made available in DSpace on 2012-11-23T15:50:27Z (GMT). No. of bitstreams: 1 elo-de-oliveira-rodrigues.pdf: 697936 bytes, checksum: fb3899c2c6d659498d8e8ab0a1a0b33a (MD5) Previous issue date: 2009 / Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil. / O Instituto de Tecnologia em Imunobiológicos, Biomanguinhos, é uma unidade da FIOCRUZ produtora de vacinas, biofármacos e reativos. O Departamento de Controle de Qualidade, pertencente a unidade de Biomanguinhos, é responsável pelos diversos ensaios físico-químicos, microbiológicos e biológicos para liberação dos produtos finais, produtos intermediários e matérias-primas. Devido à necessidade de normalizar seus ensaios referentes a produtos finais e intermediários, várias medidas têm sido tomadas como: calibração e qualificação de equipamentos, validação de métodos analíticos, aquisição de padrões, entre outras atividades de melhoria. Uma das dificuldades encontradas pelos laboratórios de controle de qualidade é a aquisição de padrões que tenham características semelhantes aos produtos produzidos em Biomanguinhos. A disponibilidade de materiais de referência/padrões que atendam às necessidades do laboratório e a dificuldade em obtê-los, além dos custos elevados, os tornam impeditivos para uso nos ensaios rotineiros. Esta dissertação tem como objetivo estabelecer a prática da produção de material de referência in housepara os métodos que são utilizados para o controle de qualidade de produtos obtidos em Biomanguinhos. O planejamento eelaboração do material de referência de trabalho serão realizados considerando-se todas as condições necessárias para que a substância candidata atenda às normas vigentes relacionadas à normalização de métodos de controle de qualidade. A implantação da metodologiae dos requisitos necessários para obtenção do material serão descritos neste trabalho. O material “candidato” a material de referência é opolirribosil-ribitol fosfato, o PRRP, que após conjugação com a proteína monomérica tetânica, torna-se o princípio ativo da vacina contra Haemophilus influenzae, a vacina Hib. A avaliação do material de referência candidato é baseada nos estudos de caracterização, homogeneidade e estabilidade, utilizando-se ferramentas estatísticas adequadas, visando à atribuição do seu valor com uma incerteza de medição associada, atendendo aos propósitos desejados e agregando maior confiabilidade aos produtos analisados pelo laboratório. Além do uso interno, há a intenção de produzir este material de referência emitindo certificado de acordo com as normas vigentes, e assim fornecê-lo também para o INCQS, órgão da FIOCRUZ responsável pelo controle de qualidade nacional de vacinas e medicamentos. / The Institute of Technology in Immunobiologicals, Biomanguinhos, is a vaccine, biopharmaceuticals, and diagnostic kits production unit that belongs to Fiocruz. The Quality Control Department is responsible for the many physical-chemical, microbiological, and biological assays performed to release the final and intermediate products and the raw materials. Due to the need of standardization of the assays, some measures have been being taken, such as equipments’ calibration and qualification, validation of analytical methods, and standards purchase. One of the challenges faced by the quality control laboratories is the acquisition of standards that have the same characteristics as the Biomanguinhos products. The low availability of standards and reference materials that attend the laboratories’ needs and the difficulties in obtaining these products, besides the high costs, make their use in the laboratories routine almost impossible. This thesis intends to establish the production practice for the in-house reference materials used in Biomanguinhos’ quality control assays. The planning and elaboration of the reference materials will be made according to the current legislation that concerns the standardization of quality control methods. The deployment of the methodology and of the requirements for the material obtainment will be discussed in this work. The ‘candidate’ to be a reference material is the polyrribosil ribitol phosphate (PRRP) that, after conjugation with the tetanical monomeric protein, becomes the active substance of the Haemophilus influenzaevaccine (Hib). The evaluation of the candidate material is based in characterization, homogeneity and stability studies, using suitable statistical tools, in order to assign its value with an associated measurement uncertainty. It aggregates reliability to the products analyzed in the laboratories. Besides the internal use, the purpose of this work is to certify the reference material in accordance with the current regulations, so that itcan be more trustable and therefore be used by INCQS, Fiocruz unit responsible for the nationalquality control of vaccines and other pharmaceutical products.

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