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Showing 41 to 49 of 49 (0.018 seconds)| 41 |
Estudo do efeito da adição de gorduras alternativas na cristalização da manteiga de cacau / Influence of the addition of alternative fats on cocoa butter crystallizationQuast, Leda Battestin 15 April 2008 (has links)
Orientadores: Theo Guenter Kieckbusch, Valdecir Luccas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-10T18:45:44Z (GMT). No. of bitstreams: 1
Quast_LedaBattestin_D.pdf: 1972832 bytes, checksum: a34ffd60e85d88858ba49961e507cd34 (MD5)
Previous issue date: 2008 / Resumo: A influência da incorporação de gorduras alternativas low e zero trans na cristalização da manteiga de cacau foi avaliada através da caracterização física de misturas binárias de manteiga de cacau com gordura de cupuaçu, gordura CBR low trans e gordura CBS, nas proporções de 5, 10, 15, 20, 25 e 30 %. O processo de pré-cristalização (temperagem) foi realizado em um reator encamisado de escala piloto dotado de um agitador e com capacidade para 700 mL. As amostras foram caracterizadas através da curva de sólidos, tensão de ruptura (snap test), calorimetria diferencial de varredura e difração de raios-X. A melhor condição de pré-cristalização da manteiga de cacau pura (taxa de resfriamento de 1,8 ºC/min, cristalização à 24 ºC por um tempo de 8 minutos) também foi utilizada nos ensaios com as misturas, com exceção das amostras com 20, 25 e 30 % de CBR e CBS que foram pré-cristalizadas a 23 ºC por 10 minutos. A manteiga de cacau apresentou um perfil de fusão de gordura na boca, DS(25ºC-35ºC), de 59,2 %, que sofreu apenas pequenas alterações com a adição de até 20 % de cupuaçu e até 30 % de CBR. A curva do conteúdo de sólidos sugere a formação de um eutético entre a manteiga de cacau e a gordura CBS. A tensão de ruptura para a manteiga de cacau foi de 2,48 kgf/cm2 e a adição das gorduras tende a diminuí-la, sendo que com 30 % de cupuaçu e 30 % de CBR esse valor foi 1,90 kgf/cm2 e 1,81 kgf/cm2, respectivamente. Para a amostra com 30 % de CBS a tensão de ruptura baixou para 0,39 kgf/cm2. Observou-se uma diminuição do ponto de fusão das misturas quando comparadas à da manteiga de cacau pura. A difração de raios-X identificou a forma cristalina b como predominante para a manteiga de cacau e para a gordura de cupuaçu enquanto que para as gorduras CBR e CBS a principal forma cristalina é a b'. A incorporação de apenas 10 % das gorduras CBR e CBS à manteiga de cacau promoveu interferências na estruturação cristalina das amostras. O estudo indicou ser possível adicionar até 30 % de gordura de cupuaçu ou CBR e até 10 % de gordura CBS sem alterar de forma sensível os atributos físicos da manteiga de cacau / Abstract: Physical properties of pre-crystallized cocoa butter with the addition of alternative low and zero trans fats were studied. Binary mixtures of cocoa butter were conducted using cupuassu fat, CBR low trans and CBS at 5, 10, 15, 20, 25 and 30 % (w/w) levels. Pre-crystallization was carried out using a lab scale jacket vessel (700 mL) whit stirring system. Samples were evaluated by means of solid fat content, snap test, differential scanning calorimetry and X-Ray diffraction. The better condition for plain cocoa butter pre-crystallization was determined as follows: cooling rate (1,8 ºC/min), crystallization time (8 minutes), crystallization temperature (24 ºC). These conditions were also used for mixtures precrystallization (tempering). Mixtures with 20, 25 and 30 % of CBR and CBS were pre-crystallized at 23 ºC for 10 minutes. Regarding to solid fat content, cocoa butter fusion profile DS(25ºC-35ºC) was 59,2 %. Similar values were obtained for mixtures with up to 30 % of cupuassu and up to 30 % of CBR fats. Mixtures with CBS fat indicated eutectic effect. Snap value for crystallized cocoa butter was 2,48 kgf/cm2. The snap values decreased with the increase of the alternative fats proportion. Mixtures containing cupuassu fat or CBR have similar trend regarding to snap values profile. For mixtures with 30 % of cupuassu and CBR the snap values were 1,90 kgf/cm2 and 1,81 kgf/cm2, respectively. CBS 30% have the lowest
snap value (0,39 kgf/cm2). Similar trend was observed regarding to melting point. Alternative fats incorporation decreased the melting point of the mixtures. Regarding to X-Ray diffraction, cocoa butter and cupuassu fat patterns results showed the formation of ß phase. For CBS and CBR patterns, there are evidence of ß¿ phase formation. The addition of 10 % CBR and CBS fat to cocoa butter was detected by X-ray diffraction patterns. The addition of up to 30 % cupuassu or CBR fat, and up to 10 % CBS butter showed no significant differences of physical properties when compared to cocoa butter / Doutorado / Engenharia de Processos / Doutor em Engenharia Química
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The Revolution of 1989 in Czechoslovakia - Comparison of Memories in the Czech Republic and AbroadCrawley, Stephen John Chetwode January 2014 (has links)
This diploma thesis is attempting to analyze the events of November and December 1989 in Czechoslovakia through the eyes of English-speaking witnesses, both at the time and in retrospect, using English language sources. The goal of the thesis is to distill from the analysis notions of freedom and whether there are perceptions of change since 1989. Included in the definition of "freedom" is the means by which it was achieved.
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Implication de la région Abcg1-U2af1 dans le syndrome de Down : effets de doses de la région et rôle du gène Cbs dans les défauts de mémorisationMarechal, Damien 06 December 2012 (has links) (PDF)
Le syndrome de Down (SD), ou Trisomie 21, est l'aneuploïdie la plus fréquente chez l'humain. Le désordre génomique est tel qu'aucun traitement unique ne peut pallier à tous les symptômes (retard mental, troubles moteurs...). C'est pourquoi l'utilisation de modèles murins permet d'étudier l'impact de régions partielles du Hsa21 dans l'apparition des déficits. Mon projet de thèse s'est orienté sur un locus télomérique encadré par les gènes Abcg1 et U2af1. Mes recherches se sont focalisées sur deux modèles, Ts1Yah et Ms2Yah, dédiés à cette région. L'étude de ces lignées, combinées à d'autres modèles transgéniques, a montré la contribution de l'intervalle génique dans l'optimisation de l'apprentissage locomoteur. Dans un deuxième temps, le gène Cbs, candidat à la perte de fonction de mémoire, a permis de mettre en évidence un sauvetage fonctionnel dans une expérience à effets de doses. Cette découverte ouvre la voie à de nouvelles perspectives thérapeutiques.
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An investigation into the representations of environmental issues relating to Lake Victoria, Uganda, and their negotiation by the lakeside communities / An exploration of how CBS radio represents and constructs environmental issues relating to Lake Victoria, Uganda, and the negotiation of the radio programmes by lakeside communitiesLwanga, Margaret Jjuuko Nassuna January 2013 (has links)
The state of the environment is increasingly present as an urgent concern for contemporary political, social, cultural and physical life. Yet the roles of the mass media (radio, television and newspapers) in shaping and influencing crucial public awareness, debates and environmental decision-making remain inadequately understood. Positioned as a critical studies inquiry into media representations and audience reception, this study forms part of a wider project amongst media scholars and culture critics on the relationship between media textual production and consumption. It explores how one radio station in Uganda, Central Broadcasting Service (CBS) radio, represents and constructs the environmental crises faced by Lake Victoria, especially pollution and overfishing. The focus is on the Victoria Voice radio documentaries aired on CBS radio in the year 2005. The study further explores how three lakeside communities negotiate these issues as radio broadcasts. It recognises that while the mass media contribute significantly to creating public awareness about such social concerns, their likelihood of having a direct and predictable impact on social behaviour is slight. The context and the lived experiences at the reception stage where the decisions are made on whether to adopt an innovation are ultimately the factors which impact on how they are negotiated. The thesis is informed by the theoretical and analytical framework of Cultural Studies as well as the Participatory Approach to Communication for Development perspectives. The study is specifically informed by the theories of ‘discourse’ (Foucault, 1980a, 1981) and the ‘circuit of culture’ (du Gay et al., 1997 and Johnson, 1987) and these provided the conceptual framework for investigating the representations, the production and the consumption of media texts. Predominantly qualitative methods have been employed in data collection and analysis. In the first place, a Critical Discourse Analysis (CDA) (Fairclough, 1995a, 1995c) of the radio texts has interrogated the discourses and discursive practices of CBS’ Victoria Voice environmental radio programmes in order to consider its representations of particular issues and consequently the discourses it privileged. Qualitative methods of participant observation, in-depth interviews and focus group discussions were deployed to investigate the negotiation of the texts by the lakeside communities. This research establishes that the Victoria Voice radio texts foreground three contesting types of discourses: the discourse of basic economic survival and livelihoods is articulated largely by the ordinary people, the lakeside communities; the discourse of sustainable development, particularly the protection and sustainability of Lake Victoria, by scientists and environmental experts; and the discourse of modernisation and corporate investment by politicians and/or policy makers and industrialists. The texts, to a large degree, reaffirm the hegemonic relations of power in Ugandan society, and thus contribute to the maintenance of the status quo. The selection of an elite category of informers (scientists, experts, politicians, policy makers) serves to marginalise the less powerful ordinary people (the fisher folk, farmers and other eyewitnesses). The construction of the elite as active and speaking subjects within the various debates introduced in these programmes, for example, works both to obscure and endorse the unequal power relations. At the reception side, while the lakeside communities attest to the relevance of the programmes in providing information on the issues concerning Lake Victoria and other aspects of their livelihood, they also recognise the power relations that underpin the sets of representations. Amongst these sets is government’s complicity with industry, in line with their economic policies and the global capitalist economy, while espousing the rhetoric of nature conservation. The study argues that sustainable solutions for the crises on Lake Victoria should take into account the socio-historical and cultural contexts of the lakeside communities. For the Ugandan media, particularly radio, there is a need to rethink the nature of the coverage, which tends to neglect the contextual factors, such as local socio-economic and cultural factors within which environmental issues and problems occur and which, as this thesis establishes, greatly influences the way people make sense of environmental issues and problems. I posit that the Participatory Approach that seeks to address the communities’ most pressing concerns should be adopted – to include more of the communities’ voices and involve them in the production of radio programmes.
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O papel das tecnologias de informação e comunicação na oferta de serviços financeiros para a população de baixa renda: o caso dos correspondentes bancários do Banco LemonYokomizo, Cesar Akira 20 March 2009 (has links)
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Previous issue date: 2009-03-20T00:00:00Z / Algumas abordagens recentes chamaram a atenção para a importância das empresas mobilizarem sua capacidade produtiva para solucionar problemas das classes menos favorecidas da sociedade. Especificamente para o caso de serviços financeiros, defende-se que a atuação na baixa renda tem implicações positivas na sociedade como um todo, ao promover sua re-inclusão no sistema tradicional. Dentro desse cenário, as iniciativas de microfinanças parecem jogar luz a esse problema ao tentar levar acesso a serviços financeiros para a população de baixa renda. Porém, tais iniciativas ainda parecem não ter demonstrado o seu real potencial, e prova disso é a persistência dos crônicos indicadores de pobreza e de desigualdade social. Isso acontece porque as abordagens atuais de microfinanças apresentam limitações, dentre as quais as tecnológicas são uma das mais importantes. Por outro lado, existe um fenômeno que se manifesta especificamente no Brasil e que se refere ao grande crescimento dos chamados correspondentes bancários (CBs), em que o correspondente, que, na maior parte das vezes, é um varejo, oferta serviços em nome do banco. Alguns estudos relacionam esses dois conceitos, microfinanças e CBs, e propõem o CB como um canal tecnológico para a promoção das microfinanças. Dentro desse cenário, uma pergunta pertinente e ainda pouco explorada na literatura é: como ocorrem a adoção, implementação e uso das tecnologias de correspondentes bancários na oferta de serviços financeiros para a população de baixa renda no Brasil? De posse dessa pergunta de pesquisa, procedeu-se a um estudo de caso em profundidade e o objeto de estudo foi a forma de atuação do Banco Lemon, em especial, por possuir uma extensa rede de CBs, ser baseado exclusivamente em CBs (não tem agências físicas) e estar focado na baixa renda. A partir de uma abordagem que inclui contribuições das escolas do estruturacionismo, do construtuvismo e do contextualismo, foi possível entender como ocorreu o processo de negociação entre dois grupos relevantes, o Banco Lemon e o gestor de redes, que é um intermediário entre o banco e o varejo, na formação da tecnologia que foi adotada, implementada e usada. Os principais achados da pesquisa referem-se ao entendimento de como a tecnologia é usada para prover os serviços que o Banco Lemon quer ofertar e como dois grupos relevantes interagem, negociam e produzem a tecnologia na prática. / Recent approaches highlighted the importance of companies to redirect their productive capacity in order to meet the needs of lower-income people. When it touches financial services, some advocate participating in the lower-income segment has positive impacts on the whole society, since it brings them back to the formal market. In this context, since microfinance initiatives try to deliver financial services to the poor, they seem to throw light on this issue. On the other hand, these initiatives have not yet shown their full potential– persistent chronic poverty and inequity indicators are still at high rates. This may happen because the current microfinance initiatives have limitations, and the technological aspects are among the most important ones. At the same time, another phenomenon that takes place in Brazil is the great growth of the so-called correspondent banking (CB), where the correspondent, most of it retail shops, offer services on behalf of the bank. Some recent studies relate these two concepts–microfinance and CB–, and propose the CB as a technological channel to foster microfinance. In this regard, there is a pertinent but still scarcely developed question in the literature: how do adoption, implementation and use of the correspondent banking technology take place in the supply of financial services to the lowerincome population in Brazil? Taking this research question into account, a deep case study was conducted and its object was Banco Lemon’s way of running businesses, mainly, because it possesses a large CB network, it is based exclusively on CBs–no branches–and it is focused on the lower-income population. Using an approach that included contributions from the body of knowledge of structuralism, constructivism and contextualism, it was possible to understand how was the negotiation held between two relevant groups–Banco Lemon itself and the network integrators, which are intermediaries between Banco Lemon and the retail–in the formation of the adopted, implemented and used technology. Main findings of this research refer to the understanding of how technology is used to provide the services Banco Lemon wants to deliver and how two different relevant groups interact, negotiate and produce the technology in the practice.
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Formal and incremental verification of SysML for the design of component-based system / Vérification formelle et incrémentale de spécifications SysML pour la conception de systèmes à base de composantsCarrillo Rozo, Oscar 17 December 2015 (has links)
Vérification Formelle et Incrémentale de Spécifications SysML pour la Conception de Systèmes à Base de ComposantsLe travail présenté dans cette thèse est une contribution à la spécification et la vérification des Systèmes à Base de Composants (SBC) modélisé avec le langage SysML. Les SBC sont largement utilisés dans le domaine industrielet ils sont construits en assemblant différents composants réutilisables, permettant ainsi le développement de systèmes complexes en réduisant leur coût de développement. Malgré le succès de l'utilisation des SBC, leur conception est une étape de plus en plus complexe qui nécessite la mise en {\oe}uvre d'approches plus rigoureuses.Pour faciliter la communication entre les différentes parties impliquées dans le développement d'un SBC, un des langages largement utilisé est SysML, qui permet de modéliser, en plus de la structure et le comportement du système, aussi ses exigences. Il offre un standard de modélisation, spécification et documentation de systèmes, dans lequel il est possible de développer un système, partant d'un niveau abstrait, vers des niveaux plus détaillés pouvant aboutir à une implémentation. %Généralement ces systèmes sont faits plus grands parce qu'ils sont développés avec des cadres logiciels.Dans ce contexte nous avons traité principalement deux problématiques.La première est liée au développement par raffinement d'un SBC modélisé uniquement par ses interfaces SysML. Notre contribution permet au concepteur des SBC de garantir formellement qu'une composition d'un ensemble de composants élémentaires et réutilisables raffine une spécification abstraite d'un SBC. Dans cette contribution, nous exploitons les outils: Ptolemy pour la vérification de la compatibilité des composants assemblés, et l'outil MIO Workbench pour la vérification du raffinementLa deuxième problématique traitée concerne la difficulté de déterminer quoi construire et comment le construire, en considérant seulement les exigences du système et des composants réutilisables, donc la question qui en découle est la suivante: comment spécifier une architecture SBC qui satisfait toutes les exigences du système? Nous proposons une approche de vérification formelle incrémentale basée sur des modèles SysML et des automates d'interface pour guider, par les exigences, le concepteur SBC afin de définir une architecture de système cohérente, qui satisfait toutes les exigences SysML proposées. Dans cette approche nous exploitons le model-checker SPIN et la LTL pour spécifier et vérifier les exigences.Mots clés: {Modélisation, Spécifications SysML, Architecture SBC, Raffinement, Compatibilité, Exigences, Propriétés LTL, Promela/SPIN, Ptolemy, MIO Workbench} / Formal and Incremental Verification of SysML Specifications for the Design of Component-Based SystemsThe work presented in this thesis is a contribution to the specification and verification of Component-Based Systems (CBS) modeled in SysML. CBS are widely used on the industrial field, and they are built by assembling various reusable components, allowing developing complex systems at lower cost.Despite the success of the use of CBS, their design is an increasingly complex step that requires the implementation of more rigorous approaches.To ease the communication between the various stakeholders in a CBS development project, one of the widely used modeling languages is SysML, which besides allowing modeling of structure and behavior, it has capabilities to model requirements. It offers a standard for modeling, specifying and documenting systems, wherein it is possible to develop a system, starting from an abstract level, to more detailed levels that may lead to an implementation.In this context, we have dealt mainly two issues. The first one concerns the development by refinement of a CBS, which is described only by its SysML interfaces and behavior protocols. Our contribution allows the designer of CBS to formally ensure that a composition of a set of elementary and reusable components refines an abstract specification of a CBS. In this contribution, we use the tools: Ptolemy for the verification of compatibility of the assembled components and MIO Workbench for refinement verification.The second one concerns the difficulty to decide what to build and how to build it, considering only system requirements and reusable components. Therefore, the question that arises is: how to specify a CBS architecture, which satisfies all system requirements? We propose a formal and incremental verification approach based on SysML models and interface automata to guide, by the requirements, the CBS designer to define a coherent system architecture that satisfies all proposed SysML requirements. In this approach we use the SPIN model-checker and LTL properties to specify and verify requirements.Keywords: {Modeling, SysML specifications, CBS architecture, Refinement, Compatibility, Requirements, LTL properties, Promela/SPIN, Ptolemy, MIO Workbench}
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Entropy Maximisation and Open Queueing Networks with Priority and Blocking.Kouvatsos, Demetres D., Awan, Irfan U. January 2003 (has links)
No / A review is carried out on the characterisation and algorithmic implementation of an extended product-form approximation, based on the principle of maximum entropy (ME), for a wide class of arbitrary finite capacity open queueing network models (QNMs) with service and space priorities. A single server finite capacity GE/GE/1/N queue with R (R>1) distinct priority classes, compound Poisson arrival processes (CPPs) with geometrically distributed batches and generalised exponential (GE) service times is analysed via entropy maximisation, subject to suitable GE-type queueing theoretic constraints, under preemptive resume (PR) and head-of-line (HOL) scheduling rules combined with complete buffer sharing (CBS) and partial buffer sharing (PBS) management schemes stipulating a sequence of buffer thresholds {N=(N1,¿,NR),0<Ni¿Ni¿1,i=2,¿,R}. The GE/GE/1/N queue is utilised, in conjunction with GE-type first two moment flow approximation formulae, as a cost-effective building block towards the establishment of a generic ME queue-by-queue decomposition algorithm for arbitrary open QNMs with space and service priorities under repetitive service blocking with random destination (RS-RD). Typical numerical results are included to illustrate the credibility of the ME algorithm against simulation for various network topologies and define experimentally pessimistic GE-type performance bounds. Remarks on the extensions of the ME algorithm to other types of blocking mechanisms, such as repetitive service blocking with fixed destination (RS-FD) and blocking-after-service (BAS), are included.
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Electron Transfer and Other Reactions Using Atomic Metal AnionsButson, Jeffery M. 04 February 2014 (has links)
The atomic metal anions Rb-, Cs-, Cu-, Ag- and Fe- have been generated in the gas phase and reacted with various neutral reactants in a triple quadrupole mass spectrometer. The metal anions were formed via electrospray ionization of the metal-oxalate solutions and form in gas phase between the capillary and the first quadrupole. Neutral gas phase reactants investigated include NO, NO2, SO2, C6F5OH, C6F5NH2, C6F6, E-octafluoro-butene and 1,2,3/1,2,4/1,3,5 trifluoro-benzene. When possible, CBS-4M methods were used to suggest the lowest energy products based on relative energy. Observed reactions of atomic metal anions with the aforementioned neutral species include electron transfer and dissociative electron transfer to the neutral gas phase reactants. In addition, hydrogen abstraction and fluorine abstraction forming a neutral metal hydride or fluoride as well as the formation of multiply substituted metal-oxide/fluoride anions was also observed. Metal-complex anions observed from the gas phase reactions include CuF-,CuF2-,CuO-,CuO2-, FeO-, FeO2-, FeO3-, FeF-, FeF2-, FeF3-, CsF- and CsF2-.
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Electron Transfer and Other Reactions Using Atomic Metal AnionsButson, Jeffery M. January 2014 (has links)
The atomic metal anions Rb-, Cs-, Cu-, Ag- and Fe- have been generated in the gas phase and reacted with various neutral reactants in a triple quadrupole mass spectrometer. The metal anions were formed via electrospray ionization of the metal-oxalate solutions and form in gas phase between the capillary and the first quadrupole. Neutral gas phase reactants investigated include NO, NO2, SO2, C6F5OH, C6F5NH2, C6F6, E-octafluoro-butene and 1,2,3/1,2,4/1,3,5 trifluoro-benzene. When possible, CBS-4M methods were used to suggest the lowest energy products based on relative energy. Observed reactions of atomic metal anions with the aforementioned neutral species include electron transfer and dissociative electron transfer to the neutral gas phase reactants. In addition, hydrogen abstraction and fluorine abstraction forming a neutral metal hydride or fluoride as well as the formation of multiply substituted metal-oxide/fluoride anions was also observed. Metal-complex anions observed from the gas phase reactions include CuF-,CuF2-,CuO-,CuO2-, FeO-, FeO2-, FeO3-, FeF-, FeF2-, FeF3-, CsF- and CsF2-.
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