Dans cette thèse expérimentale, on s'intéresse aux collisions de gouttes mettant en jeu des interfaces asymétriques, soit deux gouttes constituées de liquide différent ou des gouttes de taille différente et recouvertes (ou non) d'une couche de particules hydrophobes. Dans une première partie, on étudie les collisions de gouttes de liquide immiscible. L'asymétrie de tels systèmes repose alors sur le contraste des propriétés des deux liquides : la tension de surface, la viscosité et la densité. Le résultat de ces collisions est une encapsulation totale d'un liquide par un autre ou une encapsulation suivie d'une fragmentation. On s'attache à décrire les régimes observés et à établir des lois permettant de prédire les limites de fragmentation de l'objet obtenu. La seconde partie est consacrée aux interfaces couvertes de particules hydrophobes. Pour ces systèmes, l'asymétrie réside à la fois dans la présence des particules sur une interface et pas sur l'autre et dans le contraste de taille entre les objets étudiés. Ainsi, on considère l'impact entre une petite goutte (recouverte ou non de particules) et une très grosse goutte (recouverte ou non de particules). On caractérise tout d'abord les propriétés mécaniques de ces interfaces via la propagation d'ondes de surface, notamment en terme de tension de surface effective et de module de courbure. Puis, on sonde, dans différentes situations d'impact, la robustesse de ces objets afin d'évaluer la capacité de ces couches particulaires à prévenir la coalescence

Kauno gamybinėse vaistinėse dozuoti milteliai yra dažnai gaminama vaisto forma ir sudaro 11,58 proc. ekstemporalių kartinių vaistų. Miltelių gamyba, pakuojant į popierines kapsules, nėra pakankamai racionali. Pacientų atžvilgiu – tai nesandari laikyti ir nepatogi vartoti vaisto forma, todėl miltelius racionaliau yra pakuoti į kietąsias, skrandyje suyrančias kapsules. Šio darbo tikslas - nustatyti ir įvertinti dažniausiai vaistinėse pasitaikančių miltelių kapsuliavimo sąlygas. Tyrimo objektai yra sudėtiniai milteliai ir jais užpildytos kapsulės. Taikyti tyrimų metodai: miltelių technologinių savybių nustatymo metodai (Carr indeksas, Hausner koeficientas, kūgio kampas), kapsulių masės vienodumo ir stabilumo nustatymo – gravimetriniai metodai. Atrinktos dažniausiai vaistinėse gaminamos ekstemporalių kartinių miltelių sudėtys. Aspkaičiavus papildomus pagalbinių medžiagų kiekius atrinktoms miltelių sudėtims, jie pritaikyti pakuoti į kietąsias skrandyje suyrančias kapsules. Įvertinta papildomos pagalbinės medžiagos kiekio įtaka technologinėms miltelių mišinių savybėms ir dozavimo tikslumui. Atlikti užpildytų kapsulių kokybės ir stabilumo tyrimai stebint kapsulių masės vienodumą, turinio drėgmės kiekį ir kapsulių suirimo laiką. Parinkus dažniausiai vaistinėse gaminamų ekstemporalių kartinių miltelių receptūras, modeliuojant papildomus pagalbinės medžiagos kiekius, miltelių mišinys pritaikytas kapsuliavimui. Naudotos rankinės kapsulių pildymo mašinėlės “Capsuline – 15”, “Capsuline... [toliau žr. visą tekstą] / Powder is often produce drug form in Kaunas industrial pharmacy and consists of 11,58 per cent. Powder manufacture, packing in paper caps are not rational enough. An attitude of patient, this formulation is leaking and inconvenient to use. Powder is more rational packed in solid gastro - soluble capsules. The aim of this research is to set the encapsulation conditions of commonly occurring powder mixtures. The study objects are composite powders and hard gelatin capsules filled them. Research methods have been applied in this study: methods for determining powder technological properties (Carr index, Hausner ratio, angle of reponse), capsule mass uniformity and stability tests. Commonly produced extemporaneous powder mixtures in pharmacies were selected. Estimated an additional content of adjuvant substances for powder compositions and applied to the encapsulation of hard gelatin capsules. Evaluated influence of the estimated content of adjuvant substances on the technological properties of the powder mixture and dosing accuracy. Perform filled capsules quality and stability studies monitoring of moisture content in capsules, mass uniformity and disintegration time of capsules. Modeling of adjuvant substances quantities, powder mixture applied for capsulation. Manual capsule filling machines “Capsuline – 15”, “Capsuline – 60” and semi-automatic capsule filling machine “Feton Fastlock 100” were used. The uniformity of capsules mass and stability studies of produced... [to full text]

This thesis describes the development of microfluidic (MF) platforms for the study of biological and chemical processes. In particular the thesis is divided into two distinct parts: (i) development of a MF methodology to generate tunable cell-laden microenvironments for detailed studies of cell behavior, and (ii) the design and fabrication of MF reactors for studies of chemical reactions. First, this thesis presented the generation of biopolymer microenvironments for cell studies. In the first project we demonstrated a high-throughput MF system for generating cell-laden agarose microgels with a controllable ratio of two different types of cells. The MF co-encapsulation system was shown to be a robust method for identifying autocrine and/or paracrine dependence of specific cell subpopulations. In the second project we studied the effect of the mechanical properties on the behavior of acute myeloid leukemia (AML2) cancer cells. Cell-laden macroscopic agarose gels were prepared at varying agarose concentrations. A modest range of the elastic modulus of the agarose gels were achieved, ranging from 0.62 kPa to 20.21 kPa at room temperature. We observed a pronounced decrease in cell proliferation in stiffer gels when compared to the gels with lower elastic moduli. The second part of the thesis focuses on the development of MF platforms for studying chemical reactions. In the third project presented in this thesis, we exploited the temperature dependent solubility of CO2 in order to: (i) study the temperature mediated CO2 transfer between the gas and the various liquid phases on short time scales, and (ii) to generate bubbles with a dense layer of colloid particles (armoured bubbles). The fourth project involved the fabrication of a multi-modal MF device with integrated analytical probes. The MF device comprised a pH, temperature, and ATR-FTIR probes for in-situ analysis of chemical reactions in real-time. Furthermore, the MF reactor featured a temperature controlled feedback system capable of maintaining on-chip temperatures at flow rates up to 50 mL/hr.

No description available.

Avec l’apparition des nouvelles technologies de communication, le nombre des systèmes embarqués avionique et automobile est en constante augmentation. La gestion des communications entre ces systèmes devient alors de plus en plus complexe à mettre en oeuvre dans un contexte où les contraintes temporelles et environnementales sont très fortes et où le taux d’échanges de messages en augmentation continuelle. L’utilisation optimale des réseaux pour acheminer les données tout en respectant les contraintes temporelles imposées est essentielle du point de vue de la sûreté de fonctionnement. Historiquement, pour répondre aux problématiques d’efficacité et de sûreté, les industriels ont développé une palette de réseaux embarqués dédiés à leurs applications cibles (CAN, LIN, . . . ). Ces réseaux présentaient des débits relativement faibles à un moment où un besoin croissant en bande passante se faisait ressentir. le choix d’utiliser le concept de composants dit ‘sur étagères’ (off the shelf COTS) permettait alors de pallier à ce nouveau besoin. Dans un souci de conservation des capacités des réseaux à garantir les contraintes temporelles imposées par les systèmes embarqués temps réel, les industriels ont dû adapter ce concept de composants sur étagères aux systèmes embarqués. L’intérêt de l’utilisation de ces composants est un gain non négligeable en bande passante et en poids pour des coûts de développements relativement faibles. L’introduction de ces composants nouveaux s’est faite de telle sorte que leur impact sur les standards préexistants et les systèmes connectés soit minimal. C’est ainsi que les réseaux dit ‘hétérogènes’ ont vu leur apparition. Ces réseaux constituent une hybridation entre les technologies embarquées historiques et les composants sur étagère. Ils consistent en des réseaux d’extrémité utilisant des technologies éprouvées (telles que le CAN) interconnectés via des passerelles à un réseau fédérateur (backbone) utilisant des composants sur étagères. Dès lors, le défi majeur à relever lors de l’utilisation d’un réseau fédérateur est de respecter les contraintes temporelles des applications sollicitant les différents réseaux. L’objectif est mis à mal sur les points d’interconnexion des réseaux hétérogènes (Passerelles). Ainsi l’approche principale utilisée pour le passage d’un réseau à un autre est l’encapsulation de trames. Pour atteindre l’optimalité de performance de cette technique plusieurs paramètres sont à prendre en compte tels que le nombre de trames à encapsuler, les ordonnancements utilisés, le coût en bande passante ainsi que l’impact sur les distributions de délais (gigue). Dans l’optique de préservation des performances des réseaux, l’objet de nos travaux porte sur l’étude, la comparaison et la proposition de techniques permettant l’interconnexion de réseaux hétérogènes temps réels à la fois pour des applications à faibles et à fortes contraintes temporelles. Après un état de l’art sur les réseaux temps réel, nous spécifions différentes techniques d’interconnexion de réseaux hétérogènes, puis, nous présentons une étude de cas basée sur une architecture réseau interconnectant différents bus CAN via un réseau fédérateur sans fil Wi-Fi. L’étude que nous avons menée montre, par le biais de différentes simulations, que cette architecture réseau est une bonne candidate pour la transmission de flux à contraintes temporelles faibles. Une architecture réseau interconnectant différents bus CAN via un réseau fédérateur Ethernet commuté est ensuite considérée dans une seconde étude de cas ciblant les applications à fortes contraintes temporelles. Dans un premier temps, nous prenons en compte le cas d’un réseau fédérateur Ethernet-PQSE et, dans un second temps, le cas d’Ethernet-AVB. Cette étude nous permet de montrer l’impact des différentes techniques d’interconnexion sur les délais des flux du réseau.

Les dispositifs médicaux miniaturisés sont de plus en plus répandus dans le monde médical, car ils offrent de nouvelles opportunités de traitement et de surveillance. La miniaturisation des systèmes permet notamment une chirurgie minimalement invasive, une portabilité améliorée et une facilité d'utilisation. Parmi les exemples on peut mentionner les micro-stimulateurs cardiaques, les micro-implants cochléaires et les micro-capteurs ex-situ de glucose. Cependant, les micro-dispositifs implantables qui utilisent des technologies d'assemblage autres que les boîtiers métalliques sont encore à découvrir. La surveillance de paramètres physiologiques à l'aide de capteurs in-situ de pression et BioMEMS pourraient bénéficier des progrès faits sur les études d'encapsulation en couche mince destinées à protéger les micro-dispositifs de silicium contre la corrosion. En effet, une barrière qui empêche la diffusion et la pénétration des substances nocives est indispensable pour protéger à la fois le patient et le micro-dispositif. Les couches minces céramiques déposées par des procédés chimiques en phase vapeur sont de bons candidats grâce à leurs faibles perméabilités aux gazes, faibles réactivités chimique et conformités de dépôt élevées. Cependant, dans des milieux biologiques représentatifs du corps humain, peu d'études ont été réalisées dans le domaine de la protection des dispositifs microélectroniques contre la corrosion.Au cours de cette thèse, dix matériaux, choisis à l'issue d'une étude bibliographique, ont été étudiés: Al2O3, BN, DLC, HfO2, SiC, SiN, SiO2, SiOC, TiO2 et ZnO. Des couches ultrafines de ces matériaux (de 5 à 100 nm) ont été déposées par voie chimique en phase vapeur assisté par plasma (PECVD) ou par couches atomiques (ALD) sur des substrats silicium recouverts de matériaux généralement présents dans des dispositifs microélectroniques tels que le silicium cristallin, le cuivre, le tungstène nitrure et le poly-imide. Des mesures de cytotoxicité ont été réalisées et des tests de vieillissement ont été effectués pendant plusieurs semaines à des températures différentes dans une solution saline phosphatée (PBS) mais aussi dans une solution à base de sérum de veau fœtale (NaCl/SVF). Les changements dans la composition chimique et l'épaisseur ont été suivies par VASE, XPS et spectroscopie de masse d'ions secondaires à temps de vol (TOF-SIMS). Il a été montré que les couches de SiO2 et de SiN (généralement utilisées pour la protection dans l'industrie de la microélectronique) n'étaient pas stables dans le PBS et le NaCl/SVF à 37°C, même si en revanche elles offraient une bonne barrière aux gazes. L'Al2O3 a lui montré une très bonne tenu en milieu salin et une remarquable herméticité mais en revanche, il s'est corrodé rapidement dans le NaCl/SVF. Les couches de DLC, SiOC et TiO2 ont donné les meilleurs résultats de stabilité dans le PBS et le sérum de veau. Enfin, il a aussi été montré dans cette thèse que l'empilement TiO2 sur Al2O3 offrait la meilleure efficacité comme barrière hermétique et diffusive pour la protection des microsystèmes de silicium contre la corrosion dans les milieux salins. / Miniaturized medical devices are becoming increasingly adopted by doctors and patients because they enable new treatment and monitoring capabilities, minimally invasive surgery, improved portability and ease of use. Recent examples include micro pacemakers, micro cochlear implants and ex-situ micro glucose sensors. However, implantable micro devices employing packaging technologies other than metallic enclosures are yet to be seen. Physiological monitors such as in-situ pressure sensors and BioMEMS could profit significantly from advances in thin barrier films for corrosion protection of silicon micro devices. Coating films that stop the diffusion and permeation of harmful substances are necessary to protect both the patient and the micro device. Ceramic films deposited by chemical vapor deposition techniques are good candidates for this task due to their low permeability to gases, low chemical reactivity and high conformality. However, few studies are available about the corrosion protection offered by biocompatible coatings to microelectronic devices in representative biological environments.Ten materials were selected in this thesis after a bibliographic study: Al2O3, BN, DLC, HfO2, SiC, SiN, SiO2, SiOC, TiO2 and ZnO. Ultra-thin films of these materials (5-100 nm) were deposited by plasma enhanced chemical vapor deposition (PECVD) or atomic layer deposition (ALD) on substrates commonly found in electronic micro devices: crystalline silicon, copper, tungsten nitride and polyimide. In vitro cytotoxicity tests and degradation tests were performed for several weeks at different temperatures in Phosphate Buffer Saline (PBS) and NaCl supplemented with 10% Fetal Bovine Serum (NaCl/FBS). Changes in thickness and chemical composition were monitored by VASE, XPS and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). It was found that SiO2 and SiN films (generally used for protection in the microelectronics industry) are not stable in PBS and NaCl/FBS at 37°C, even though they act as good hermetic barriers. Al2O3 showed very good stability in saline solution and excellent behavior as gas barrier, but it was rapidly dissolved in NaCl/FBS.In contrast, films of DLC, SiOC and TiO2 showed very low chemical reactivity in both mediums. Finally, it was shown that multilayers of TiO2 on Al2O3 offer the best performance as hermetic and diffusion barriers for corrosion protection of silicon micro systems in saline environments.

[pt] O presente trabalho sugere uma alternativa inovadora para o tratamento e disposição do cascalho de perfuração, um dos mais complexos resíduos da indústria de petróleo contendo, em geral, altas taxas de sais solúveis e hidrocarbonetos. Estas características o tornam um resíduo nocivo ao meio ambiente. Neste trabalho é avaliada a incorporação de cascalho de perfuração na massa argilosa para produção de cerâmica vermelha. O método consiste no processamento industrial, realizado a elevadas temperaturas, a fim de se obter um material sólido, resistente e inerte. A incorporação de cascalho de perfuração na produção de cerâmica vermelha apresentou-se como uma alternativa economicamente viável e tecnicamente segura para o tratamento e destinação final deste resíduo. Uma vez que o processo de queima, inerente a produção de peças cerâmicas, encapsula e reduz a baixos teores os constituintes perigosos do cascalho de perfuração. Os resultados obtidos neste trabalho serviram de subsídios para a concessão de licença ambiental para utilização da técnica desenvolvida na remediação de cascalho de perfuração no Estado da Bahia. / [en] This thesis presents an innovative treatment technique for drilling cuttings, one of the most complex wastes of the oil industry. This waste is considered hazardous due to its high salt and hydrocarbons content and poses serious threats to the environment. The treatment process involves the incorporation of drilling cuttings to the clayey soil mass used for making bricks. It consists on applying high temperatures, over 8000C, to the clayey soil mass in order to obtain a solid, resistant and inert material. The results of the experimental programme have shown that this innovative process is technical safe and economical viable. As a result, Petrobras obtained an environmental license in the city of Mata de São João , State of Bahia, to produce in a large scale red bricks using drilling cuttings incorporated to the clayey soil mass.

Este trabalho tem como objetivo aplicar a técnica de encapsulamento, conhecida também como solidificação/estabilização, em um solo contaminado com crescentes quantidades do resíduo industrial borra oleosa ácida, utilizando como agente encapsulante o cimento Portland CP-V ARI. O programa experimental consistiu na realização de estudos pré e pós-tratamento, analisando fisicamente o solo através de ensaios de caracterização geotécnica, compactação, resistência à compressão simples, durabilidade e condutividade hidráulica. Quimicamente foram realizados ensaios de lixiviação em coluna e análises químicas e físico-químicas do lixiviado. Devido às elevadas temperaturas detectadas no momento das misturas de solo/cimento e borra oleosa ácida, foram realizados ensaios para o monitoramento da temperatura e o tempo de hidratação do cimento. Os resultados apontam que quanto maior a quantidade de borra oleosa ácida presente no solo tratado, maior é a temperatura de hidratação do cimento e mais rápido atinge o pico máximo, resultando em menor resistência à compressão simples e maior perda de massa. Em amostras sem cimento, a condutividade hidráulica diminui com o aumento de borra oleosa ácida, quando adicionado cimento a condutividade hidráulica inicialmente diminui com o acréscimo de borra oleosa ácida, mas volta a aumentar com quantidades maiores de contaminante. A técnica de encapsulamento mostrou-se eficiente quanto à redução dos metais pesados, devido, principalmente, ao aumento do pH e a precipitação de tais elementos. Porém não se mostrou eficiente quanto ao sulfato, condutividade elétrica e demanda química de oxigênio. / The objective of this study is applying the encapsulation technique, also known as solidification/stabilization, in soil contaminated with increasing amounts of acidic oily sludge industrial residues, using Portland cement CP-V ARI as the encapsulating agent. The experimental program consisted of studies pre and post-treatment, in which the soil was physically analyzed through geotechnical characterization testings, compactation, unconfined compressive strength, duration and hydraulic conductivity tests. In chemical terms, column leach testings were conducted, along with chemical and physical-chemical analyses of the leachete. Due to the high temperatures detected upon mixing soil/cement and the acidic oily sludge, tests were conducted to monitor the temperature and the hydratation rate of the cement. The results show that the greater the amount of acidic oily sludge in the treated soil, the higher the temperature necessary to hydrate the cement and the faster it reaches the maximum peak, which results in less unconfined compressive strength and greater mass loss. In samples without cement, the hydraulic conductivity reduced upon increasing the amount of acidic oily sludge. When cement is added, the hydraulic conductivity initially decreases with the acidic oily sludge, but it increases again with greater amounts of the substance. The encapsulation technique proved to be efficient in the reduction of heavy metals, due mainly to the pH increase and the precipitation of such components. However, the technique did not prove to be efficient in relation to sulphate, and to the electrical conductivity and the chemical oxygen demand.

ESTEVES, Laurenci Barros. Funções discursivas dos processos referenciais de encapsulamento em artigos de opinião. 2017. 113f. – Dissertação (Mestrado) – Universidade Federal do Ceará, Programa de Pós-Graduação em Linguística, Fortaleza (CE), 2017 / Submitted by Gustavo Daher (gdaherufc@hotmail.com) on 2017-03-17T12:57:20Z No. of bitstreams: 1 2017_dis_lbesteves.pdf: 1393575 bytes, checksum: 29b6c824e2084460dd55fe39dabbdd17 (MD5) / Approved for entry into archive by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2017-03-20T12:02:05Z (GMT) No. of bitstreams: 1 2017_dis_lbesteves.pdf: 1393575 bytes, checksum: 29b6c824e2084460dd55fe39dabbdd17 (MD5) / Made available in DSpace on 2017-03-20T12:02:05Z (GMT). No. of bitstreams: 1 2017_dis_lbesteves.pdf: 1393575 bytes, checksum: 29b6c824e2084460dd55fe39dabbdd17 (MD5) Previous issue date: 2017 / The main objective of this work is to analyze the discursive functions of the referential encapsulation processes in opinion pieces according to the theoretical approach of referentiation (MONDADA, 1994; MONDADA; DUBOIS, [1995] 2003). For that we proposed a (re)discussion of the formal and functional criteria that guide the definition and the analysis of the encapsulation phenomenon based on the researches by authors such as Francis ([1994] 2003), Conte ([1996] 2003), Apothéloz and Chanet ([1997] 2003) and Consten; Knees and Schwarz-Friesel (2007), who tend to give a formal treatment to the anaphoric encapsulation processes. Thus, we aligned these works with the theoretical postulates that are present in more recent studies that deal with this theme, such as the works by Ciulla and Silva (2008), Silva (2013), Alves (2015) among others. This theoretical construct was essential because it enabled us not only to verify the functioning of the anaphoric encapsulation in the texts that integrate the corpus of this dissertation, but also to study the relation between these processes of reference and the textual genre opinion piece, as well as to relate the different types of encapsulation to the attitude markers of the speaker in their text (HYLAND, 2005). Based on these objectives, we adopted a corpus consisting in 40 opinion pieces about the tv shows aired in the Brazilian television that were collected between the years of 2015 and 2016. Based on the qualitative analysis of the corpus, it was found that the discursive functions of the anaphoric encapsulation processes and of the referential encapsulation introductions are linked to two macrofunctions: (i) metadiscursive macrofunction, which integrates the following fuctions: a) the evaluative function; b) the introduction and encapsulation of referents; c) the function of hypostasizing pragmatic-discursive units; (ii) organizing macrofunction, which envolves: a) glossing function; b) enumerative function; c) the function of promoting topical organization. Moreover, it was also possible to verify that the encapsulation referential processes and the opinion piece genre are interinfluenced, which is probably due to the preference of the encapsulations for texts where there is a predominance of the argumentative sequence. Finally, this work also contributes with na important theoretical reflection on the importante of the encapsulations based on works published throughout the years by focusin on discoursive aspects and possible relations with text-discursive traits. / Esta dissertação possui como objetivo principal analisar, à luz da abordagem teórica da referenciação (MONDADA, 1994; MONDADA; DUBOIS, [1995] 2003), as funções discursivas dos processos referenciais de encapsulamento em artigos de opinião. Para tanto, propôs-se uma (re)discussão dos critérios formais e funcionais que norteiam a definição e a análise do fenômeno do encapsulamento com base nas pesquisas de autores como Francis ([1994] 2003), Conte ([1996] 2003), Apothéloz e Chanet ([1997] 2003) e Consten, Knees e Schwarz-Friesel (2007), cujos trabalhos preconizam um tratamento essencialmente formal aos encapsulamentos, alinhando-os aos postulados teóricos presentes em trabalhos mais recentes que tratam da temática em pauta, como os estudos de Ciulla e Silva (2008), Silva (2013) e Alves (2015). Esse percurso teórico permitiu reorganizar os processos referenciais atrelados à menção com a adição da introdução referencial encapsuladora, bem como verificar o funcionamento dos encapsulamentos nos textos que integram o corpus desta dissertação para, dessa forma, poder relacioná-los às marcas de posicionamento do locutor em seu texto (HYLAND, 2005). O corpus adotado neste estudo foi composto por 40 artigos de opinião sobre a programação da televisão brasileira, coletados entre os anos de 2015 e 2016, cuja análise permitiu concluir que as anáforas encapsuladoras e as introduções referenciais encapsuladoras respondem, no gênero em questão, a duas macrofunções: (i) macrofunção metadiscursiva, que se desdobrou em: a) função avaliativa; b) função de introduzir e encapsular referentes; c) função de hipostasiar unidades pragmático-discursivas; (ii) macrofunção organizadora, que se fragmentou em: a) função de glosa; b) função enumerativa; c) função de promover a organização tópica. Tais funções não são mutuamente excludentes e são necessárias tanto para a organização, quanto para a edificação da argumentatividade textual. Além disso, também foi possível verificar que os processos referenciais de encapsulamento e o gênero artigo de opinião se interinfluenciam, o que se deve à predileção dos encapsulamentos por textos em que há uma predominância da sequência argumentativa. Este trabalho deixa uma importante reflexão teórica sobre os estudos de encapsulamento realizados ao longo dos anos, cotejando aspectos descritivos e observando possíveis relações que podem manter com traços textual-discursivos.

O yacon (Smallanthus sonchifolius) é uma raiz de origem andina, considerada como um alimento funcional por apresentar em sua composição frutoligossacarídeos (FOS) e compostos fenólicos. Os FOS são polímeros de frutose com grau de polimerização de 3-10 e têm sido designados como prebióticos e fibras alimentares por sua não digestibilidade pelas enzimas do trato digestivo humano e por estimulando seletivamente o crescimento e a atividade de bactérias intestinais promotoras de saúde. Além da ação prebiótica, as raízes de yacon são ricas em compostos fenólicos com propriedades antioxidantes, que protegem o corpo humano dos processos oxidativos. Entretanto, a presença desses compostos torna as raízes suscetíveis à reação de escurecimento enzimático causado pela peroxidase e polifenoloxidase. Diante disso, inicialmente, foi estudada a cinética da inativação térmica e parâmetros termodinâmicos durante o branqueamento dessas enzimas e da enzima inulinase no suco de yacon. O suco de yacon, previamente acidificado com 1% de ácido cítrico foi branqueado com diferentes combinações de tempo-temperatura na faixa de 0-10minutos e 80-100 ºC. O comportamento cinético das três enzimas indicou a presença de duas isoenzimas com diferentes estabilidades térmicas, seguindo o modelo bifásico. A análise cinética demonstrou ainda, a alta resistência térmica das enzimas avaliadas, sendo que a inulinase foi a mais resistente ao calor. A análise termodinâmica indicou que a adição do ácido cítrico ao suco de yacon, provavelmente, causou a desnaturação da maior parte das enzimas que posteriormente foram agregadas durante o branqueamento. Posteriormente, o suco de yacon foi microencapsulado por atomização a fim de avaliar o uso da polidextrose como material de parede através da comparação com a goma arábica que é um dos encapsulantes mais utilizados em alimentos. Os efeitos da concentração dos agentes encapsulantes e da temperatura de secagem no teor de compostos fenólicos totais, atividade antioxidante, frutoligossacarídeos, umidade, atividade de água, solubilidade, higroscopicidade, cor e morfologia foram investigados. Os resultados indicaram que a polidextrose apresentou bom desempenho no microencapsulamento de componentes bioativos do suco de yacon, apresentando alta retenção dos compostos fenólicos e da atividade antioxidante. Em todos os tratamentos avaliados teve comportamento muito similar à goma arábica apresentando boas características, tais como baixa umidade, atividade de água e higroscopicidade e elevada solubilidade. Posteriormente, a cinética e termodinâmica de degradação dos compostos fenólicos e a cinética da degradação da diferença total de cor dessas microcápsulas foram avaliadas sob condições de cinética acelerada de armazenamento, com umidade relativa de 75 e 90% e temperaturas de 35 e 45 ºC. As microcápsulas foram atomizadas na temperatura de 140 ºC com goma arábica e polidextrose na proporção de 10% e armazenadas nessas condições por 35 dias. A degradação dos compostos fenólicos e da diferença total de cor das microcápsulas exibiram cinética de primeira ordem. Em relação à degradação dos compostos fenólicos, para todas as condições de umidade e temperatura, as microcápsulas com goma arábica foram mais estáveis do que as encapsuladas com polidextrose, apresentando maiores tempos de meia vida. Entretanto, os valores dos parâmetros termodinâmicos tiveram valores similares, indicando que a degradação dos fenóis ocorreu de forma similar nas microcápsulas independente do material de parede utilizado. As constantes de velocidades da degradação da diferença total de cor das microcápsulas não apresentaram diferença significativa com o aumento da temperatura e/ou da umidade relativa. Paralelamente, foi avaliada a estabilidade do bagaço de yacon desidratado através das isotermas de sorção e análise termodinâmica. O bagaço é o subproduto do processo de extração do suco, tem baixa atividade de água e potencial para uso em formulações alimentícias devido ao teor de FOS que permanece mesmo após a secagem. Os dados de umidade de equilíbrio de bagaço de yacon desidratado em pó foram determinados nas temperaturas de 20, 30, 40 e 50 ºC e o modelo de Halsey ajustou adequadamente os dados de sorção. As isotermas obtidas foram do tipo III, características de produtos contendo açúcares. / Yacon (Smallanthus sonchifolius) is a root of Andean origin, considered to be a functional food as it presents fructooligosaccharides (FOS) and phenolic compounds in its composition. FOS are fructose polymers with a polymerization degree of 3–10 units and have been referred to as prebiotics and dietary fibers because they are not digestible by the enzymes of the human digestive tract and they selectively stimulate the growth and activity of of health promoting bacteria. Other than their prebiotic action, yacon roots are rich on phenolic compounds with antioxidant properties, which protect the human body from oxidative processes. However, the presence of such compounds makes the roots susceptible to enzymatic browning reaction caused by peroxidase and polyphenoloxidase. Thereby, initially, a study was conducted on the kinetics of thermal inactivation and thermodynamic parameters during blanching of these enzymes as well as inulinase enzyme on yacon juice. The yacon juice, previously acidified with 1% citric acid was blanched with different time-temperature combinations in the ranges of 0-10 minutes and 80-100 °C. The kinetic behavior of the three enzymes indicated the presence of two isoenzymes with different thermal stabilities, following the biphasic model. Furthermore, the kinetic analysis showed high thermal resistance for the evaluated enzymes, where in inulinase was the most heat resistant. Thermodynamic analysis indicated that the adding of citric acid to the yacon juice, probably, caused the denaturation of the most of the enzymes that were subsequently aggregated during blanching. Afterwards, yacon juice was microencapsulated by spray drying with the aim of evaluating the use of polydextrose as wall material through in comparison to gum arabic, which is one of the more often used encapsulants in food. The effects of the concentration of the encapsulating agents and drying temperature in the content of total phenolic compounds, antioxidant activity, fructooligosaccharides, moisture, water activity, solubility, hygroscopicity, color, and morphology were investigated. The results indicated that polydextrose presented a good performance in the encapsulation of yacon juice, presenting high retention of phenolic compounds and antioxidant activity. On all the evaluated treatments, a behavior similar to arabic gum was observed, presenting good characteristics, such as low moisture content, water activity and hygroscopicity and high solubility. Hereafter, the kinetics and thermodynamics of the degradation of phenolic compounds and the kinetics of the degradation of the total color difference of these microcapsules were evaluated under accelerated storage kinetics conditions, with relative humidity of 75 and 90% and temperatures between 35 and 45 °C. The spray drying process was performed under a temperature of 140°C with arabic gum and polydextrose in a 10% concentration and stored under such conditions for 35 days. Degradation of phenolic compounds and total color of microcapsules showed first order kinetics. As of phenolic compound degradation, for all the conditions of relative humidity and temperature the microcapsules with arabic gum were more stable than the ones encapsulated with polydextrose, presenting longer half-lives. Nevertheless, values for the thermodynamic parameters were similar, indicating that the degradation of the phenols occurred in a similar way in the microcapsules, regardless of the wall material used. The kinetic analysis for total color difference of the microcapsules showed that the increase in temperature and/or relative humidity caused no significant difference on the the rate constants. Meantime, the stability of dehydrated yacon bagasse was evaluated by use of sorption isotherms and thermodynamic analysis. The bagasse is a byproduct of the juice extraction process, with low water activity and potential for usage in food formulations due to residual FOS content, even after drying. Equilibrium moisture data for powdered dehydrated yacon bagasse was determined under temperatures of 20, 30, 40, and 50°C and the Halsey model suitably adjusted to the sorption data. The isotherms thus obtained were class III isotherms, typical of sugar rich products.