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Etude des interactions physico-chimiques des ingrédients fonctionnels des crèmes desserts et de leurs impacts sur leurs microstructures et leurs propriétés sensorielles / Improvement of tailored food development of neutral dairy desserts through linking chemical-physics interactions of ingredients, structure set up and sensory perception of the productsMatignon, Anne 19 June 2013 (has links)
L'appellation ‘desserts laitiers neutres' regroupe de nombreux produits de composition similaire mais de structure et de texture différente. Trois de leurs composants et leurs interactions définissent leur structure : l'amidon, les carraghénanes et les protéines de lait. L'objectif de cette thèse était de mieux appréhender les mécanismes physico-chimiques impliqués dans la mise en place de la structure de ces produits et leur impact sur la perception sensorielle.Ce travail s'est focalisé sur les interactions entre l'amidon et les carraghénanes en présence ou non de protéines de lait. De l'amidon modifié de maïs cireux, du lait écrémé reconstitué et des kappa-carraghénanes ont été utilisés. Différentes interactions ont été mises en avant par l'utilisation d'outils rhéologiques et microscopiques. En mélange binaire le carraghénane s'adsorbe sur le granule d'amidon gonflé. Cette interaction dépend de la densité de charge, et de la masse moléculaire du carraghénane utilisé. En mélange ternaire le carraghénane interagit préférentiellement avec les micelles de caséines et ce quel que soit le moment ou le lait est ajouté (avant ou après empesage de l'amidon). Cette modification de l'ordre d'incorporation des ingrédients permet d'obtenir des produits de microstructures différentes. Dans les deux cas les granules d'amidon sont inclus dans un réseau carraghénanes / micelles de caséines mais les caractéristiques de ces deux phases (amidon et carraghénanes / micelles de caséines), responsables de la structuration des produits, sont modifiées. Afin d'en évaluer l'impact sur la perception sensorielle de crèmes, neuf produits de formules identiques mais assemblés différemment ont été fabriqués. Un tri libre, suivi d'un classement des groupes sur des termes discriminants à consonance personnelle, ont été mis en place. Des différences entre les produits ont été perçues. Ces différences ont été décrites par des termes de texture corrélés à des mesures instrumentales de texture.Ce travail a permis de mettre en avant les mécanismes physico chimiques déterminants dans la mise en place de la structure ainsi que leur potentiel impact sur les propriétés sensorielles de produits de type crèmes desserts. Ces connaissances pourraient être mises à profit dans des démarches de conception raisonnée ou de rétro ingénierie pour formuler de nouveaux produits. / Neutral dairy desserts are composed of a large diversity of products of similar composition but different structures and textures. Their structure set up is defined by the interactions between three of their quantitatively minor components: starch, milk proteins and carrageenan. The objective of this PhD project was to better understand the chemical-physics mechanisms beyond the neutral dairy desserts structure set up and their impact on the sensory perception of the product.The study focused on single, binary and ternary mixtures containing starch. It was performed with a modified waxy maize starch, reconstituted skim milk and kappa carrageenan mostly. Using rheological and microscopic tools, different interactions were highlighted. In binary mixtures, carrageenan was found to adsorb on the starch granules. A specific study on those interactions pointed out that they depended on carrageenans' charge density and molecular weights. In ternary mixtures, preferential carrageenan / casein micelles interactions in comparison to starch / carrageenan ones were pointed out even when milk proteins were added after starch pasting in a carrageenan solution. The addition of milk before or after starch pasting led to products of same formula but different microstructures. Starch granules were in both cases embedded in a carrageenan / casein micelles network still, the starch granules states or characteristics and the network formed differed. Dispersed starch and carrageenan / milk phases were defined as the key structure parameters of neutral dairy desserts. To assess their impact on sensorial perception, nine products of same formula but built differently were produced. The evaluation was done by subjects by means of a free sorting task followed by a ranking task on free discriminating terms. Sensory differences were found between the products. These differences were characterized and correlated with instrumental attributes.This work permitted to collect numerous data on chemical-physics properties, link them to the structure set up and to their potential impact on sensory properties of dairy creams. All this knowledge would be easily used to improve tailor food development and particularly to formulate new dairy cream texture through a reverse engineering approach.
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Ochrana spotřebitele / Consumer protectionKotová, Šárka January 2010 (has links)
The work is divided into 2 parts. First part deals with general level of consumer protection. It specifies consumers discretions and duties, analyses concrete laws that govern consumer protection and institutional reinsurance of consumer protecion in the Czech Republic. The second part analyses situation in foodstuff area, it warns against traps of the market and underline quality brands, which can make consumer's choice easier.
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Sänkt temperatur i kylkedjan : Konsekvenser för transportbranschen / Decreased temperature in the cold chain : Consequences for the transportBjörkgren, Anton, Eriksson Sjöqvist, Edvin January 2017 (has links)
Idag transporteras kylda livsmedel, i Sverige, inom ett temperaturintervall på +2 °C - +8 °C. I vilken temperatur som animaliska livsmedel ska hanteras i regleras i lagstiftningen och varierar mellan +2 °C - +7 °C. Många kylskåp, både hos butik och konsument, är inställda på+8 °C. Till följd av detta är den stora majoriteten livsmedel, på förpackningen, markerade med en förvaringstemperatur på +8 °C. På senare år har diskussioner förts angående en sänkt temperatur i kylkedjan. Anledningen till detta är att överkomma matsvinnet. Forskning pekar på att ett livsmedels hållbarhet är starkt beroende av dess förvaringstemperatur. Hastigheten på mikrobiell tillväxt sjunker nämligen med lägre temperaturer. År 2020 träder en ny förordning om fluorerade växthusgaser (fgasförordningen)i kraft som förbjuder installation och påfyllning av kommersiell utrustning innehållande köldmedier med högre Global Warming Potential-faktor än 2500. Detta innebär att butiksledet i stor utsträckning kommer tvingas byta ut sina äldre kylsystem. Med nya kylsystem kan en lägre temperatur garanteras. För att vara väl förberedda ställer sig transportbranschen frågan vilka konsekvenser en sänkttemperatur kan tänkas föra med sig i deras del av kedjan. Problematiken grundar sig i att en del livsmedel kan ta skada av temperaturer nära fryspunkten. För att skydda dessa livsmedelkan transportören använda sig av produktskydd på kylkänsliga livsmedel. En annan beprövad metod är att dela in livsmedlen i flera temperaturzoner. Arbetets teoretiska bidrag är att det sammanställer tidigare forskning på områden inom livsmedelsegenskaper vid nedkylning, multitemperatursystem och produktskydd samt semistrukturerade intervjuer med experter inom sina respektive områden. Vidare undersöksäven kylkedjans uppbyggnad och dess aktörer. Perspektivet i rapporten utgår från ett av de större transportföretagen inom tempererad logistik i Sverige. Arbetets praktiska bidrag är baserat på en fallstudie som tillsammans med det teoretiska bidraget ligger till grund för en redogörelse över tänkbara konsekvenser. Analysen visar på att en del livsmedel, för att inte komma till skada och riskera kassation, måste skyddas. Antingen genom flera temperaturzoner eller genom produktskydd. Bådaalternativen kommer med för- och nackdelar. Att addera flera temperaturzoner för med sig investeringar i form av mellanväggar och kylsystem samt komplicerar livsmedelshanteringen. Flera temperaturzoner kan emellertid säkra ett livsmedels kvalitet. För produktskydden existerar det inget returlogistiksystem och ett system kan bli mycket kostnadsdrivande att upprätthålla. Slutsatsen är att en kombination av de båda lösningarna är att föredra men att branschöverskridande samarbete krävs för att samtliga parter ska gynnas. / Chilled foodstuffs are today transported within a temperature interval of +2 °C - +8 °C in Sweden. The correct temperatures in which foodstuffs with animal origin should be handled in are regulated by law and diverges between +2 °C - +7 °C. Many refrigeration systems in grocery stores and consumer’s homes are set at +8 °C. The great majority of foodstuffs are, as a result of this, on the packaging marked with a storage temperature of +8 °C. To be well prepared, the transport industry ask themselves which consequences might occur in case of a reduced temperature in the cold chain. The main reason for this is to overcome food waste. Research shows that foodstuffs durability is highly dependent on its storage temperature. The rate in which microbial growth occur drops with falling temperatures. In2020 a new EU regulation enters in to force which regulates the use of refrigerants with higher Global Warming Potential factor than 2500. The grocery stores have to, as a result of this, replace many of their older refrigeration systems. Regulating lower temperatures won’t be an issue with new modern equipment. As a result of this they can guarantee lower temperatures on foodstuff. To be prepared for what might come, the transport industry wants to know what consequences a lower temperature might bring along in their part of the cold chain. The main issue is that some foodstuff might be harmed in temperatures close to the freezing point. The use of protective coatings could offer shelter for cold sensitive products. One other proven method is to allocate foodstuff in different temperature zones. This thesis theoretical contribution compiles earlier research in areas such as foodstuffs characteristics when refrigerated, multi temperature systems, protective coatings and semi structured interviews with experts within their fields. It further examines the cold chain and the stakeholders within it. The focus of the thesis is thru the perspective of one of the major transport companies within cold chain logistics in Sweden. The practical contribution is based on a case-study together with the theoretical contribution which states consequences that possibly can occur along the transport company’s part of the cold chain. The analysis shows that, to minimize the risk of cassation, some foodstuffs need protection. Either thru multiple temperature zones or with protective covers. Both alternatives comes with advantages and disadvantages. To add temperature zones are associated with investments in the form of separable walls and cooling systems together with an increase in logistic complexity. Multi temperature systems can however secure the quality in a foodstuffs quality. The issue with protective covers is that there’s no return logistics system in place and such a system can be very expensive to uphold. The covers do however offer protection from outer temperature influence. The conclusions states that a combination of both solutions might be suitable. To accomplish this however requires collaboration over company and industry borders if all stakeholders are to be beneficial.
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Concreto de alto desempenho em ambientes com baixas temperaturas / High performance concrete in low temperature environmentLima, Sandra Maria de 06 March 2006 (has links)
O objetivo de colaborar com o equacionamento da problemática do crescimento populacional por meio de uma proposta viável economicamente, e com vantagens tecnológicas com vistas à durabilidade para a armazenagem de gêneros alimentícios em baixas temperaturas motivou o desenvolvimento desta pesquisa, na qual se propõe o uso do concreto como material alternativo para a construção de sistemas de guarda e conservação de alimentos. A partir de um adequado método de dosagem e da tecnologia desenvolvida pelo grupo de pesquisadores do Laboratório de Materiais Avançados à Base de Cimento, foram elaborados dois concretos diferenciados pela incorporação ou não de ar. A durabilidade do concreto para ambientes com baixas temperaturas tem sido relacionada a um sistema de vazios de ar com volume de 6 '+ OU -' 1 % e adequado espaçamento entre as bolhas de ar. O desempenho desses concretos em ambientes com baixas temperaturas foi avaliado acondicionando-os em uma câmara fria com temperatura de - 35 ± 2 graus Celsius. A sanidade dos corpos-de-prova foi monitorada por meio de ensaios não destrutivos (i.e. determinação da freqüência natural). O período de exposição foi de trinta e cinco dias, sendo que após o sétimo dia ocorreu a estabilização dos valores da freqüência natural dos corpos-de-prova. Os dois tipos de concretos ensaiados - com ar incorporado e sem ar incorporado - mostraram-se resistentes nestas condições de ensaio. Os resultados obtidos demonstram que os concretos, de acordo com o método utilizado, atendem a todos os requisitos para os quais foram projetados / The aim to collaborate with the set out of the world population increase problem, using a feasible and economical proposal, with technology advantages, destined to store foodstuff in low temperatures, motivated the development of this research, that suggests concrete as an alternative material to storage and conservation foodstuff system construction. Starting from the concrete design with an adequate method, and based on the technology developed by worker group of Laboratory of Advanced Cement Based Materials, were designed two kinds of concrete: with and without incorporated air. The durability of concrete in low temperatures environment were related to air voids system with 6 '+ OU -' 1% of air content, and to adequate spacing between air voids. The concrete behaviour in low temperatures environment was evaluated placing the specimens in a cold chamber, whose temperatures were about -35 '+ OU -' 2 Celsius degrees. The integrity of the specimens was evaluated by non-destructive method (determination of natural frequency). The exposure period of the specimens was thirty five days, but at seventh day the natural frequencies values were stabilized. Both kind of concrete were resistant in this condition. The obtained results show that concretes, in conformity to the used methodology, performed all requirement for that were designed
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Concreto de alto desempenho aplicado a sistemas de processamento e armazenagem de alimentos em baixas temperaturas / High performance concrete applied to storage and processing system buildings at low temperaturesLima, Sandra Maria de 20 October 2008 (has links)
O desenvolvimento de um concreto de alto desempenho aplicado a sistemas de processamento e armazenagem de alimentos em baixas temperaturas teve por objetivo atender às indústrias de alimentos no Brasil que se utilizam da tecnologia do frio em seu processo industrial. A hegemonia mundial do mercado de carnes é brasileira, sendo que nossas indústrias são responsáveis por 33% desse mercado. A ausência de estudos para aprimorar e tornar as plantas industriais mais duráveis e condizentes com a importância do setor foi determinante na delineação do tema desta tese. Desenvolveu-se um concreto de alto desempenho frente às possíveis situações em uma planta industrial: baixas temperaturas em ambientes secos e baixas temperaturas em ambientes sujeitos à umidade. A temperatura mínima a qual foram submetidos os concretos analisados foi de 35°C. O método de dosagem e as diretrizes calcadas no reforço da matriz da pasta de cimento e refinamento de poros mostraram-se como uma alternativa para vencer as agressividades causadas pelas baixas temperaturas ao concreto. Até então, estudos sugeriam um sistema de ar cujos vazios teriam diâmetros em torno de 250 µm espaçados com esta mesma distância entre eles e com conteúdo de 6±1% para a proteção de concretos expostos a baixas temperaturas. A produção de um concreto coeso, com teor de ar de 3,5%, poros com diâmetro médio de 0,02 µm e com área específica de 2,84m²/g, provaram ser duráveis quando expostos ao congelamento e a ciclos de gelo e degelo. O fator de durabilidade para esses concretos foi de 97%. Além da durabilidade, o projeto de dosagem contemplou o aspecto econômico, produzindo 1MPa com 7,8 kg de cimento por metro cúbico de concreto. Os resultados foram obtidos por meio de ensaios dinâmicos, microscopia eletrônica de varredura, porosimetria por intrusão de mercúrio, absorção de água por imersão, além dos ensaios mecânicos de resistência à compressão, à tração na flexão e módulo de elasticidade. / Brazil has rapidly emerged as one of the world\'s leading meat exporters, being responsible by 33% of this market. In face of that, a high performance concrete (HPC), that can be applied to storage and processing system buildings at low temperatures, has been developed with the aim of answering the needs of brazilian food manufacturers that use cooling technology during industrial process. The lack of studies to improve industrial plants and make them more durable was determinant to delineate this thesis subject. A high performance concrete was designed to resist to low temperatures at dry environments as well as at moist ones. Concrete was exposed to a target temperature of -35°C. The dosage method and the guidelines based on the strengthening of bulk cement and the porous refinement showed to be an alternative to overcome the aggressiveness caused by low temperatures to concrete. To this day, studies have suggested air voids systems to protect concrete from low temperature effects. According to them, the air voids should have about 250 µm of diameter, spaced from each other this same distance and with an air content of 6±1%. However, making a cohesive concrete, with 3,5% of air content and an average diameter porous of 0,02 µm with an specific surface of 2,84m²/g, resulted in a durable concrete, even when exposed to frost / thawing cycles. The durability factor of these concretes achieved 97%. Besides durability, the dosage design brought economical advantages, producing 1 MPa with 7,8 kg of cement per cubic meter of concrete. The results were obtained through dynamic tests, scanning electron microscopy, mercury intrusion porosimetry and water absorption by immersion. In addition, tests of compression, tension strength and elastic modulus were carried out.
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Valstybinės maisto ir veterinarijos tarnybos įvežamų negyvūninių maisto prekių maisto kontrolės postų efektyvumo tobulinimas / Improvement of the efficiency of non-animal orgin foodstuff import control posts of state food and veterinary serviceBilkienė, Danguolė 15 December 2006 (has links)
Darbo tikslas - ištirti Lietuvos Valstybinės maisto ir veterinarijos tarnybos negyvūninių maisto prekių importo kontrolės egzistuojančią valdymo sistemą ir jai pavaldžiu teritoriniu VMVT maisto kontrolės postu veiklos efektyvumą, įvertinant negyvūninių maisto prekių importo kontrolės tvarką, taikomą jos veikloje, ir numatyti šios veiklos tobulinimo kryptis. / Aim of the study: to analyze the management of the control system of non - animal origin imported foodstuffs and the efficiency of the activities of regional State Food and Veterinary Services (hereinafter - SFVS), in order to evaluate import control procedures of non – animal origin foodstuffs applied within the SFVS, as well as to foresee improvement possibilities for these activities.
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Potraviny nejsou odpadZIEGLER, Martin January 2017 (has links)
The thesis is concerned with a basic fact about the issue of food waste in a global level and in the Czech Republic as well. It Describes the overall problem and distinguishes a terminology of food loss, food waste etc. The practical part analyzes the consumption of food consumers via questionnaire in the region of Tabor. The goal was to determine whether the respondents are knowledgeable in this matter another aim was to find out the frequency of their purchase and consumption of food in their homes or how they liquidate the remaining food. The challenge is also to propose the own solution of this problem, because waste represents a complex economic, environmental, social and ethical problem. The final part deals with its own proposals for solutions and it finds out the need to establish food banks in the region of Tabor.
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Esforço para inovação tecnológica : uma caracterização da indústria de alimentos do município de Marília/SP.Abreu, Andréia de 02 October 2007 (has links)
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Previous issue date: 2007-10-02 / In the light of the entrepreneurial scenario, in which new competitiveness
patterns were established, companies have been forced to search for new manners of action in
order to survive the market. Among these forms, it is highlighted those which favor the
development of technological innovations and the establishment of cooperation relationships
among several partners. This same reality applies to the foodstuff industry. The development
of technological innovations has been increasingly important since they are capable of
providing the products the market need, as well as aimed at guaranteeing food safety
throughout its production and as final good already ready to consumption. Another manner
the companies adopt to overcome troubles and become more innovative is the insertion in
cooperative ventures, which occurs because these companies do not have necessary resources,
including knowledge to adopt and transfer innovation to their products and processes, or
because they want to reduce the risks related to innovation practices. According to this
scenario, the present work in intended for characterizing the efforts to establish technological
innovation and cooperative relationships to innovation on foodstuff companies based in
Marília, São Paulo, thus making possible to identify actions to aid the development and
adoption of technologies in the companies studied. Besides, this work is aimed at identifying
and evaluating how these cooperation relationships are established. In order to do so, case
studies were carried out in four foodstuff companies. As a result, it was verified that the
companies promoted a great deal of effort in order to introduce technological innovation to
their products, processes or both. / Diante do atual cenário empresarial, no qual novos padrões de competitividade
foram estabelecidos, as empresas têm sido forçadas a procurarem novas formas de atuação
para sobreviver no mercado. Entre as inúmeras formas, destacam-se aquelas que privilegiam o
desenvolvimento de inovações tecnológicas e o estabelecimento de relações de cooperação
entre diversos parceiros. Na indústria de alimentos, a realidade é a mesma. O
desenvolvimento de inovações tecnológicas tem se tornado cada vez mais importante, pois as
novas tecnologias, além de serem capazes de fornecer produtos que o mercado deseja, têm o
objetivo de garantir a segurança do alimento durante o processo de produção e no seu estado
de produto final, pronto para consumo. Uma outra forma encontrada pelas empresas deste
segmento para superar as dificuldades e tornarem-se mais inovadoras é a inserção em arranjos
cooperativos. Isto ocorre devido ao fato de não possuírem todos os recursos necessários ou
porque desejam reduzir os riscos associados à inovação. De acordo com este cenário, este
trabalho tem como objetivo caracterizar o esforço para a inovação tecnológica e as relações de
cooperação para inovação em empresas alimentícias do município de Marília/SP,
possibilitando identificar ações que possam auxiliar o desenvolvimento e a adoção de
tecnologia nas empresas estudadas. Além disso, este trabalho visa identificar e avaliar como
são estabelecidas relações de cooperação para a introdução de inovações nessas empresas.
Para que os objetivos fossem alcançados, foram realizados estudos de caso em quatro
empresas alimentícias do município. Como resultado, foi constatado que as empresas
estudadas promoveram importantes esforços visando o desenvolvimento de inovações
tecnológicas em produto, em processo ou em ambas.
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Concreto de alto desempenho aplicado a sistemas de processamento e armazenagem de alimentos em baixas temperaturas / High performance concrete applied to storage and processing system buildings at low temperaturesSandra Maria de Lima 20 October 2008 (has links)
O desenvolvimento de um concreto de alto desempenho aplicado a sistemas de processamento e armazenagem de alimentos em baixas temperaturas teve por objetivo atender às indústrias de alimentos no Brasil que se utilizam da tecnologia do frio em seu processo industrial. A hegemonia mundial do mercado de carnes é brasileira, sendo que nossas indústrias são responsáveis por 33% desse mercado. A ausência de estudos para aprimorar e tornar as plantas industriais mais duráveis e condizentes com a importância do setor foi determinante na delineação do tema desta tese. Desenvolveu-se um concreto de alto desempenho frente às possíveis situações em uma planta industrial: baixas temperaturas em ambientes secos e baixas temperaturas em ambientes sujeitos à umidade. A temperatura mínima a qual foram submetidos os concretos analisados foi de 35°C. O método de dosagem e as diretrizes calcadas no reforço da matriz da pasta de cimento e refinamento de poros mostraram-se como uma alternativa para vencer as agressividades causadas pelas baixas temperaturas ao concreto. Até então, estudos sugeriam um sistema de ar cujos vazios teriam diâmetros em torno de 250 µm espaçados com esta mesma distância entre eles e com conteúdo de 6±1% para a proteção de concretos expostos a baixas temperaturas. A produção de um concreto coeso, com teor de ar de 3,5%, poros com diâmetro médio de 0,02 µm e com área específica de 2,84m²/g, provaram ser duráveis quando expostos ao congelamento e a ciclos de gelo e degelo. O fator de durabilidade para esses concretos foi de 97%. Além da durabilidade, o projeto de dosagem contemplou o aspecto econômico, produzindo 1MPa com 7,8 kg de cimento por metro cúbico de concreto. Os resultados foram obtidos por meio de ensaios dinâmicos, microscopia eletrônica de varredura, porosimetria por intrusão de mercúrio, absorção de água por imersão, além dos ensaios mecânicos de resistência à compressão, à tração na flexão e módulo de elasticidade. / Brazil has rapidly emerged as one of the world\'s leading meat exporters, being responsible by 33% of this market. In face of that, a high performance concrete (HPC), that can be applied to storage and processing system buildings at low temperatures, has been developed with the aim of answering the needs of brazilian food manufacturers that use cooling technology during industrial process. The lack of studies to improve industrial plants and make them more durable was determinant to delineate this thesis subject. A high performance concrete was designed to resist to low temperatures at dry environments as well as at moist ones. Concrete was exposed to a target temperature of -35°C. The dosage method and the guidelines based on the strengthening of bulk cement and the porous refinement showed to be an alternative to overcome the aggressiveness caused by low temperatures to concrete. To this day, studies have suggested air voids systems to protect concrete from low temperature effects. According to them, the air voids should have about 250 µm of diameter, spaced from each other this same distance and with an air content of 6±1%. However, making a cohesive concrete, with 3,5% of air content and an average diameter porous of 0,02 µm with an specific surface of 2,84m²/g, resulted in a durable concrete, even when exposed to frost / thawing cycles. The durability factor of these concretes achieved 97%. Besides durability, the dosage design brought economical advantages, producing 1 MPa with 7,8 kg of cement per cubic meter of concrete. The results were obtained through dynamic tests, scanning electron microscopy, mercury intrusion porosimetry and water absorption by immersion. In addition, tests of compression, tension strength and elastic modulus were carried out.
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Concreto de alto desempenho em ambientes com baixas temperaturas / High performance concrete in low temperature environmentSandra Maria de Lima 06 March 2006 (has links)
O objetivo de colaborar com o equacionamento da problemática do crescimento populacional por meio de uma proposta viável economicamente, e com vantagens tecnológicas com vistas à durabilidade para a armazenagem de gêneros alimentícios em baixas temperaturas motivou o desenvolvimento desta pesquisa, na qual se propõe o uso do concreto como material alternativo para a construção de sistemas de guarda e conservação de alimentos. A partir de um adequado método de dosagem e da tecnologia desenvolvida pelo grupo de pesquisadores do Laboratório de Materiais Avançados à Base de Cimento, foram elaborados dois concretos diferenciados pela incorporação ou não de ar. A durabilidade do concreto para ambientes com baixas temperaturas tem sido relacionada a um sistema de vazios de ar com volume de 6 '+ OU -' 1 % e adequado espaçamento entre as bolhas de ar. O desempenho desses concretos em ambientes com baixas temperaturas foi avaliado acondicionando-os em uma câmara fria com temperatura de - 35 ± 2 graus Celsius. A sanidade dos corpos-de-prova foi monitorada por meio de ensaios não destrutivos (i.e. determinação da freqüência natural). O período de exposição foi de trinta e cinco dias, sendo que após o sétimo dia ocorreu a estabilização dos valores da freqüência natural dos corpos-de-prova. Os dois tipos de concretos ensaiados - com ar incorporado e sem ar incorporado - mostraram-se resistentes nestas condições de ensaio. Os resultados obtidos demonstram que os concretos, de acordo com o método utilizado, atendem a todos os requisitos para os quais foram projetados / The aim to collaborate with the set out of the world population increase problem, using a feasible and economical proposal, with technology advantages, destined to store foodstuff in low temperatures, motivated the development of this research, that suggests concrete as an alternative material to storage and conservation foodstuff system construction. Starting from the concrete design with an adequate method, and based on the technology developed by worker group of Laboratory of Advanced Cement Based Materials, were designed two kinds of concrete: with and without incorporated air. The durability of concrete in low temperatures environment were related to air voids system with 6 '+ OU -' 1% of air content, and to adequate spacing between air voids. The concrete behaviour in low temperatures environment was evaluated placing the specimens in a cold chamber, whose temperatures were about -35 '+ OU -' 2 Celsius degrees. The integrity of the specimens was evaluated by non-destructive method (determination of natural frequency). The exposure period of the specimens was thirty five days, but at seventh day the natural frequencies values were stabilized. Both kind of concrete were resistant in this condition. The obtained results show that concretes, in conformity to the used methodology, performed all requirement for that were designed
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