Sociala medier och framför allt Instagram har kommit att få en mer betydande roll i det vardagliga livet där vi interagerar och delar gemensamma intressen med varandra. Att ta bilder på mat och dela dem med varandra har blivit ett av de vanligaste objekten som läggs upp på sociala medier, varför gör folk det? Uppsatsens syfte är att ta reda på hur sociala medier används i vardagen hos personer i åldrarna 36-45 år som lever i barnfamiljer och hur detta påverkar vad de lagar för mat. Vid inhämtning av data användes fyra kvalitativa semistrukturerade intervjuer som kompletterades med metoden scroll-along. Där författaren gick igenom informanternas digitala miljö för att få en bättre förståelse för deras vardagliga användande. Resultatet i studien visade på att sociala medier användes av deltagarna för att inhämta inspiration och recept samtidigt som detta sällan ledde till att dem ändrade sina måltidsbeteenden och rätter de valde att tillaga mer än temporärt. Kokbokens användning i medelinkomstfamiljerna var begränsad vilket ledde till ifall inhämtande av recept från sociala medier och matbloggar är den nya kokboken. Detta kunde inte fastställas i denna studie då mer studier behövs inom ämnet och är någonting för framtida forskning. / Social media and especially Instagram has got a more meaningful part in the daily life where we are interacting and sharing our common interests with each other. If there is one object on social media that has become the most common it must be to take pictures of food and share them with others, why do people do that? The intention of this study is to see how social media is used in the daily life of people in the ages 36-45 that lives in families with children and how that affects what food they are making. The data was collected through four qualitative semi-structured interviews that was completed by the scroll-along method. Where the author went through the informant’s digital environment to get a better understanding of their daily social media-usage. The result indicates that the participants used social media to get inspirited and collected recipes whereas on the other hand rarely made them change their meal behavior and dishes they usually cooked more than just temporary. The usage of the cookbook in the middle income families was limited and led to if collecting recipes from social media and food blogs is the new cookbook. This could not be confirmed in this study because more studies within this subject is needed and is something to study more in the future.

Made available in DSpace on 2014-12-17T14:57:47Z (GMT). No. of bitstreams: 1 JoaoDPV.pdf: 1303151 bytes, checksum: 407305d41d4b24852e57967eeba5cfd5 (MD5) Previous issue date: 2007-08-17 / Companies involved in kaolin mining and treatment represent an important area of industrial development in Brazil, significantly contribution to the worldwide production of such mineral. As a result, large volumes of kaolin residue are constantly generated and abandoned in the environment, negatively contributing to its preservation. In this scenario, the objective of the present study was to characterize the residue generated from kaolin mining as well as to assess its potential use as raw material for the production of ceramic tiles. Ceramic mixtures were prepared from raw materials characterized by X-ray fluorescence, X-ray diffraction, particle size analysis and thermal analysis. Three compositions were prepared using kaolin residue contents of 10%, 20% and 30%. Samples were uniaxially pressed, fired at 1200?C and characterized aiming at establishing their mineralogical composition, water absorption, apparent porosity, specific mass, linear retraction and modulus of rupture. The results showed that the residue basically consisted of kaolinite and successfully replaced raw kaolin in the preparation of ceramic title formulations without significantly affecting the properties of the fired material / As ind?strias de minera??o e beneficiamento de caulim s?o um importante segmento econ?mico do pa?s, com uma produ??o bastante significativa no cen?rio internacional. Em fun??o disso, a produ??o de res?duos ? muito grande, poluindo e agredindo o meio ambiente. Assim, esse trabalho tem por objetivo a caracteriza??o do res?duo do beneficiamento do caulim e a avalia??o de sua aplicabilidade como mat?riaprima alternativa na produ??o de cer?mica de revestimento. As mat?rias-primas utilizadas neste trabalho foram caracterizadas por t?cnicas de: fluoresc?ncia de raios X; difra??o de raios X; analise granulom?trica; an?lise termogravim?trica e an?lise termodiferencial. Foram formuladas tr? s composi??es contendo o res?duo de caulim, em propor??es de 10%, 20%, e 30%. Foram confeccionados corpos-de-prova por prensagem e suas massas foram queimadas a 1200?C e caracterizadas qu?mica e mineralogicamente com o objetivo de identificar suas composi??es, seus elementos e suas fases. Estes corpos-de-prova foram avaliados quanto ? absor??o de ?gua, porosidade aparente, massa espec?fica aparente, retra??o linear, difra??o de raios X e o m?dulo de ruptura ? flex?o. Pode-se concluir que o res?duo de caulim ? constitu?do basicamente por caulinita, e que a incorpora??o nas propor??es estudadas teve resultados altamente satisfat?rios nas formula??es, para a produ??o de cer?micas de revestimento

Made available in DSpace on 2014-12-17T14:57:51Z (GMT). No. of bitstreams: 1 AndreaSP.pdf: 1820286 bytes, checksum: a1263199151d8fb3f317fa86bacf6014 (MD5) Previous issue date: 2006-05-19 / The State of Rio Grande do Norte, Brazil, possess major deposits of feldspar, clay, kaolin and talc, all raw materials used in the production of porcelainized stoneware tiles. Conversely, state industries manufacture only low added value red ceramics. Porcelainized stoneware tiles is one of the noblest ceramics, depicting low water absorption (typically below of 0,5%), in addition to excellent staining resistance and mechanical strength. The present work aims at investigating the potential of local raw materials for the production of porcelainized stoneware tiles. To that end, these materials were characterized by X-ray fluorescence, X-ray diffraction, particle size analysis, thermal gravimetric analysis and thermal differential analysis. Admixtures containing different compositions were prepared and fired at three temperatures, 1150, 1200 and 1250?C for 30 min. After firing, tests samples were characterized by water absorption tests, linear retraction, dilatometric analysis, apparent porosity, apparent specific mass, flexural strength, and microstructural analysis by XRD and SEM. The results revealed that ceramics with porcelainized stoneware tiles characteristics could be produced from raw materials originated in the State of Rio Grande do Norte / O Rio Grande do Norte possui grandes jazidas de pegmatitos, argilas caulin?ticas e caulim, principais mat?rias-primas para a fabrica??o de gr?s porcelanato. No entanto, o RN produz apenas produtos de baixo valor agregado em rela??o ao porcelanato, uma das mais nobres cer?micas de revestimento, devido a sua baixa absor??o d??gua (tipicamente abaixo de 0,5%), al?m de apresentar excelentes caracter?sticas t?cnicas, destacando-se elevada resist?ncia mec?nica, ao risco e ao manchamento. O presente trabalho tem a finalidade de validar o potencial de mat?rias-primas do RN (feldspato, argila, caulim e talco beneficiado) para a produ??o de gr?s porcelanato. Para isso, foi feita a caracteriza??o das mat?rias primas por FRX, DRX, AG, ATG e ATD, elaborando-se cinco formula??es que foram queimadas em tr?s temperaturas: 1150, 1200 e 1250?C com 30 minutos de patamar. Ap?s a queima, os corpos-de-prova foram submetidos a ensaios de absor??o de ?gua, retra??o linear, porosidade aparente, massa espec?fica aparente, resist?ncia ? flex?o, DRX, MEV e an?lise dilatom?trica. Obteve-se para uma das misturas, propriedades compat?veis com as exigidas para um gr?s porcelanato

Made available in DSpace on 2014-12-17T14:57:52Z (GMT). No. of bitstreams: 1 DanielJHC_TESE.pdf: 5059546 bytes, checksum: d026fcca3b608eb8f8318d620f8e0f29 (MD5) Previous issue date: 2012-02-23 / In this work, it is proposed the study of the effect of barium oxide acting as synthetic flow in the behavior of masses for stoneware from the use of raw materials found in the deposits of minerals of the Rio Grande do Norte that it makes use of a great natural potential for the industrialization of the product. The porcelanato is a sophisticated product with excellent final properties being applied as ceramic coating in buildings of high standard of engineering. The raw materials selected for the development of the study had been two types of argilas, two types of feldspatos, dolomita, talco, barium carbonate and silica, being characterized by X-ray fluorescence, X-ray diffraction, granulometric analysis, dilatometric analysis and thermal analysis. Thus, it is intended to define four formulations using the cited raw materials that will be processed, conformed and sintered in the temperatures of 1150 ?C, 1175 ?C, 1200 ?C, 1225 ?C e 1250 ?C. From the physical characterizations, chemical and morphologic of the formed formulations, the effect of barium oxide is determined in the physical and mechanical properties of the studied system carrying water absorption tests, linear retraction, apparent porosity, apparent specific mass, compacting curve, flexural strength and microstructural analysis by XRD and SEM. After analyzing the results, indicated that barium oxide acts as a flux of high temperature and as the ordering of structure, where the embedded glass phase has the nucleating effect phase potassium silico-aluminum reacting with free silica which together with the high content of potassium concentrated form a new crystalline phase called microcline. The masses studied with the addition of barium oxide present physical-mechanical properties highly satisfactory in reduced firing temperatures, which implies a saving in energy given off in the production and increased productivity / Neste trabalho, prop?e-se o estudo do efeito do ?xido de b?rio atuando como fluxo sint?tico no comportamento de massas para porcelanato a partir da utiliza??o de mat?rias-primas encontradas no estado do Rio Grande do Norte que disp?e de um grande potencial natural para industrializa??o do produto. O porcelanato ? um produto com excelentes propriedades finais, sendo aplicado como revestimento cer?mico em diversos empreendimentos da constru??o civil. As mat?rias-primas selecionadas para o desenvolvimento do estudo foram dois tipos de argilas, dois tipos de feldspatos, dolomita, talco, carbonato de b?rio e s?lica, sendo caracterizadas por an?lises de fluoresc?ncia de raios X, difra??o de raios X, an?lise granulom?trica e an?lises t?rmicas. Assim sendo, procede-se o processamento, conforma??o e sinteriza??o de quatro formula??es utilizando as mat?rias-primas citadas nas temperaturas de 1150 ?C, 1175 ?C, 1200 ?C, 1225 ?C e 1250 ?C. A partir das caracteriza??es f?sicas, qu?micas e morfol?gicas das formula??es, determina-se o efeito do ?xido de b?rio nas propriedades f?sicas e mec?nicas do sistema estudado realizando ensaios de absor??o de ?gua, retra??o linear, porosidade aparente, massa espec?fica aparente, curva de compacta??o, tens?o de ruptura a flex?o, difra??o de raios X e microscopia eletr?nica de varredura com a microan?lise por EDS. Ap?s a an?lise dos resultados, verifica-se que o ?xido de b?rio atua como fundente de alta temperatura e como ordenador de estrutura, onde incorporado ? fase v?trea, possui efeito nucleante da fase sil?cio-alum?nio-pot?ssio reagindo com a s?lica livre que juntamente com o alto teor de pot?ssio concentrado forma uma nova fase cristalina denominada microcl?nio. As massas estudadas com o acr?scimo do ?xido de b?rio apresentam propriedades f?sico-mec?nicas extremamente satisfat?rias em temperaturas de queima reduzidas, o que implica em uma economia na energia desprendida para a produ??o e aumento de produtividade / 2020-01-01

Made available in DSpace on 2014-12-17T14:57:53Z (GMT). No. of bitstreams: 1 JorgeFB.pdf: 2466045 bytes, checksum: 390a8dfd299d465779890586b1bd5be1 (MD5) Previous issue date: 2009-10-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The State Bahia, Brazil, presents different geological sites it with a very expressive variety minerals. It is situated among the very important States which produces minerals for industries, such as pointed aggregate, ornamentals stones and ceramics raw materials. Nowadays only four companies producting ceramics tiles. Porcelainized stoneware tiles is one of the noblest ceramics, depicting low water absorption (typically below of 0,5%), in addition to excellent staining resistance and mechanical strength. The present work aims at investigating the potential of local raw materials for the production of porcelainized stoneware tiles. For this purpose, these materials were characterized by X-ray fluorescence, X-ray diffraction, particle size analysis, thermal gravimetric analysis, thermal differential analysis and dilatometric analysis. Admixtures containing different compositions were prepared and fired at four temperatures, 1100 ?C, 1150 ?C, 1200 ?C and 1250 ?C with isotherm for 60 minute and heathing rate of 5 oC/min. After firing the samples, they were characterized by water absorption tests, linear retraction, analysis, apparent porosity, apparent specific mass, flexural strength, and microstructural analysis by X-ray diffraction and scanning electron microscopy . The results revealed three ceramics with porcelainized stoneware tiles characteristics and porcelain tile will be produce from raw materials originated in the State of Bahia / O Estado da Bahia apresenta uma diversidade de terrenos geol?gicos que encerra uma expressiva dota??o mineral e est? situado entre os mais importantes Estados produtores de minerais industriais, ressaltando-se agregados, rochas ornamentais e mat?rias-primas cer?micas. Atualmente somente quatro empresas produzem placas cer?micas. O gr?s porcelanato ? uma das mais nobres cer?micas de revestimento devido a sua baixa absor??o d ?gua (tipicamente abaixo de 0,5%), al?m de apresentar excelentes caracter?sticas t?cnicas, destacando-se pelas elevadas resist?ncias mec?nica, ao risco e ao manchamento. O presente trabalho tem a finalidade de avaliar o potencial das mat?rias-primas, feldspato, argila e caulim, utilizado na produ??o de gr?s porcelanato no estado da Bahia. Para isso, foi feita a caracteriza??o das mat?rias-primas por fluoresc?ncia de raios X (FRX), difra??o de raios X (DRX), an?lise granulom?trica (AG), an?lise t?rmica gravim?trica (TG), an?lise t?rmica diferencial (DTA) e an?lise dilatom?trica, elaborando-se sete formula??es que foram queimadas nas temperaturas: 1100 ?C, 1150 ?C, 1200 ?C e 1250 ?C, com isoterma de 60 minutos e taxa de aquecimento de 5 oC/ min. Ap?s a queima, os corpos-de-prova foram submetidos a ensaios de absor??o de ?gua, retra??o linear, an?lise dilatom?trica, porosidade aparente, massa espec?fica aparente, resist?ncia ? flex?o, difra??o de raios X e microscopia eletr?nica de varredura. Em tr?s formula??es foram obtidas, propriedades compat?veis com as exigidas para a produ??o do gr?s porcelanato com mat?rias-primas oriundas do Estado da Bahia

Made available in DSpace on 2014-12-17T15:03:28Z (GMT). No. of bitstreams: 1 OdeniaALS_DISSERT.pdf: 3500566 bytes, checksum: bcbbd86a88f2dade1ad704684123cb31 (MD5) Previous issue date: 2011-10-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Stabilization pond is the main technology used for treatment wastewater, in northeast Brazil, due to lower cost of deployment, operation and maintenance compared to other technologies. Most systems of stabilization ponds has been in operation for some time, on average 10 years of operation, receiving high organic loads and do not have good removal efficiencies of the main parameters for which have been designed. Therefore it is necessary to work to quantify the efficiency of current systems. This study evaluated the biodegradability of organic matter in raw sewage, the removal of organic matter in reactors and determination of the kinetic constant removal of organic matter (k), both in reactors and in raw sewage, based on the analysis made in the laboratory and through mathematical methods proposed in the literature, in nine systems stabilization ponds, located in Rio Grande do Norte. In relation the degradation kinetics in stabilization ponds, it was observed that many papers published in the literature were obtained in pilot-scale systems, which often, due to the action of external factors such as wind and temperature, these can t be considered as a reference in the analysis of the kinetic constant K, so the need for more research into systems of scale. This study had three distinct phases and simultaneous, routine monitoring, study of the daily cycle and the determination of kinetic constant of degradation of organic matter (K). The monitoring showed that the removal efficiencies of organic matter on most systems were lower than suggested by the literature, the best efficiencies of around 76% (BOD) and 72% (COD) and the worst of the order of 48% (BOD) and 55% (COD). The calculation of K in raw sewage (Ke) was within the range of variation expected in the literature (0.35 to 0.60 days-1). Already for the results obtained for K in the reactors (Kr), there were well below the values recommended in the literature (0.25 to 0.40 d-1 for complete mix and from 0.13 to 0.17 d-1 for flow dispersed), in line with the overloads that organic systems are subject / Lagoa de estabiliza??o ? a principal tecnologia utilizada para tratamento de esgotos dom?sticos no Nordeste brasileiro, devido ao menor custo de implanta??o, opera??o e manuten??o, quando comparada com outras tecnologias. A maioria dos sistemas de lagoas de estabiliza??o est? em opera??o h? bastante tempo, em m?dia 10 anos de opera??o, recebem altas cargas org?nicas e n?o apresentam boas efici?ncias de remo??o dos principais par?metros a qual foram projetadas. Portanto, faz-se necess?rio um trabalho que quantifique a efici?ncia atual desses sistemas. O presente estudo avaliou a biodegradabilidade da mat?ria org?nica no esgoto bruto, a remo??o da mat?ria org?nica nos reatores e a determina??o da constante cin?tica de remo??o de mat?ria org?nica (k), tanto nos reatores quanto no esgoto bruto, baseadas nas an?lises feitas em laborat?rio e atrav?s dos m?todos matem?ticos propostos pela literatura, em nove sistemas de lagoas de estabiliza??o, no Rio Grande do Norte. Em rela??o ? cin?tica de degrada??o em lagoas de estabiliza??o, observou-se que muitos trabalhos publicados na literatura foram obtidos em sistemas em escala piloto, o que muitas vezes, devido ? a??o de fatores externos, tais como vento e temperatura, esses n?o podem ser considerados como refer?ncia na an?lise da constante cin?tica K, por isso a necessidade de se pesquisar mais em sistemas de escala real. Essa pesquisa teve tr?s fases distintas e simult?neas: monitora??o de rotina, estudo do ciclo di?rio e a determina??o da constante cin?tica de degrada??o da mat?ria org?nica (K). O monitoramento mostrou que as efici?ncias de remo??o de mat?ria org?nica, na maioria dos sistemas, estavam abaixo do sugerido pela literatura, sendo as melhores efici?ncias da ordem de 76% (DBO) e de 72% (DQO) e as piores da ordem de 48% (DBO) e 55% (DQO). O calculo do K no esgoto bruto (Ke) mostrou-se dentro da faixa de varia??o prevista na literatura (0,35 a 0,60 dia-1). J? para os resultados obtidos para K nos reatores (Kr), verificaram-se valores bem abaixo do preconizado pela literatura (0,25 a 0,40 d-1 para mistura completa e 0,13 a 0,17 d-1 para fluxo disperso), em conson?ncia com as sobrecargas org?nicas a que os sistemas est?o sujeitos

Made available in DSpace on 2014-12-17T15:03:34Z (GMT). No. of bitstreams: 1 MiltonBV.pdf: 1188933 bytes, checksum: 0027ba3da37c2c26ef04d16c288622a2 (MD5) Previous issue date: 2006-11-30 / Waste stabilization ponds are the main technology in use for domestic sewage treatment in Rio Grande do Norte State (RN), northeast Brazil. The are around 80 systems, constructed mainly by municipal city halls, being series comprised by a primary facultative pond followed by two maturation ponds the most used configuration. Due to problems related with the production and destination of sludge and generation of bad odors, the designers have avoided the use of anaerobic lagoons. The majority of systems are rarely monitored to verify their efficiencies and to get new project parameters for future designing. This work has as purpose to make a diagnosis of efficiency of three series of waste stabilization pond series (WSPS) of Jardim Lola 1, Jardim Lola 2 and Beira Rio, located in the North Zone of the city of the Natal/RN, treating domestic raw sewage, on the removal of organic matter and thermotolerant coliform, comparing the operational conditions of the systems this inside of the bands foreseen in the project, through parameters BOD5, QOD, thermotolerant coliforms, dissolved oxygen, pH, temperature, ammoniac nitrogen, total and suspended solids. The work was carried through in the WSPS, all constituted by a primary facultative pond followed by two maturation ponds. Socioeconomic characteristics of population are predominantly low and all the plants are very near of the contributing basins. The series were monitored from of May the November of 2002, totalizing 20 collections of grab samples of raw sewage and ponds effluents between 8:00 and 9:50 h. The main aspect to be detached by the results was the great concentration of organic matter (BOD and COD) and microorganisms the raw sewage which were around two times more concentrated than those values foreseen one in project. Considering all series the highest removals of organic matter were observed in system Beira Rio (84 and 78% of BOD and COD, respectively), which presented high hydraulic detention time (TDH = 89 days). On the other hand, Jardim Lola 1 and Jardim Lola 2 presented a much lower values of HDT (36 days and 18 days respectively) and their removals of BOD and COD were the same (76% and 60%, respectively). The Beira Rio WSPS, was the most efficient verified in relation to solids and ammonia, proving the great influence of the operational variables such as HDT and applied surface organic loadings on the performance of pond series. Although the treatment plants have reached efficiencies of thermotolerant coliforms around 99,999%, the concentrations in the final effluent can be considered very high for launching in aquatic bodies, particularly those produced by Jardim Lola 1 and Jardim Lola 2 series / O sistema de lagoas estabiliza??o ? o tipo de tratamento de esgoto dom?stico mais utilizado no Estado do Rio Grande do Norte, contando com 80 sistemas, constru?dos principalmente pelas prefeituras municipais, sendo o sistema de lagoas em s?rie constitu?das de lagoa facultativa prim?ria seguida de lagoas de matura??o um dos mais utilizados. Devido aos problemas relacionados com a produ??o e destino de lodo e gera??o de maus odores, os projetistas t?m evitado o uso de lagoas anaer?bias. Vale salientar que tais sistemas de lagoas comumente n?o s?o monitorados de forma adequada para verificar suas efici?ncias e obter dados para futuros projetos. Este trabalho tem como finalidade fazer um diagn?stico da efici?ncia de tr?s s?ries de lagoas de estabiliza??o na grande Natal, Jardim Lola 1, Jardim Lola 2 e Beira Rio, na remo??o de mat?ria org?nica e coliformes termotolerantes e, verificar se as condi??es operacionais dos sistemas esta dentro das faixas previstas no projeto, atrav?s dos par?metros DBO5, DQO, coliformes termotolerantes, oxig?nio dissolvido, pH, temperatura, nitrog?nio amoniacal, s?lidos totais e suspensos. Os sistemas estudados s?o constitu?dos por uma lagoa facultativa prim?ria seguida de duas lagoas de matura??o, que atendem a uma popula??o predominante de baixa renda a qual est? bem pr?xima da esta??o de tratamento de esgoto. As tr?s ETE s foram monitoradas no per?odo de maio a novembro de 2002, totalizando 20 coletas de amostras pontuais de esgoto bruto e efluentes das lagoas entre 8:00 e 9:50 h. Os principais aspectos a serem destacados no monitoramento foram a grande concentra??o de mat?ria org?nica e microrganismos nos esgoto brutos afluentes em rela??o ao previsto em projeto. Considerando toda a s?rie as maiores remo??es de mat?ria org?nica ocorreram no sistema Beira Rio (84 e 78% de DBO e DQO, respectivamente), que apresentava um TDH de 89 dias enquanto que os sistemas de Jardim Lola 1 e 2 eram de 36 dias e 18 dias respectivamente, foram determinadas remo??es semelhantes de DBO (76%) e de DQO em torno de 60%. O sistema Beira Rio tamb?m foi o mais eficiente na remo??o de s?lidos e de nitrog?nio amoniacal, comprovando a grande influ?ncia das vari?veis operacionais tais como tempo de deten??o hidr?ulica e carga org?nica aplicada, no desempenho dos sistemas de tratamento. Embora as esta??es de tratamento tenham atingido efici?ncias de coliformes termotolerantes em torno de 99,999%, as concentra??es nos efluentes finais podem ser consideradas muito elevadas para lan?amento em corpos aqu?ticos, particularmente as de Jardim Lola 1 e 2

Made available in DSpace on 2014-12-17T15:14:50Z (GMT). No. of bitstreams: 1 FranciscoES.pdf: 1953348 bytes, checksum: d700754d09d0b7966901ab6cbebb4085 (MD5) Previous issue date: 2008-11-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Recent astronomical observations (involving supernovae type Ia, cosmic background radiation anisotropy and galaxy clusters probes) have provided strong evidence that the observed universe is described by an accelerating, flat model whose space-time properties can be represented by the FriedmannRobertsonWalker (FRW) metric. However, the nature of the substance or mechanism behind the current cosmic acceleration remains unknown and its determination constitutes a challenging problem for modern cosmology. In the general relativistic description, an accelerat ing regime is usually obtained by assuming the existence of an exotic energy component endowed with negative pressure, called dark energy, which is usually represented by a cosmological constant ? associated to the vacuum energy density. All observational data available so far are in good agreement with the concordance cosmic ?CDM model. Nevertheless, such models are plagued with several problems thereby inspiring many authors to propose alternative candidates in the relativistic context. In this thesis, a new kind of accelerating flat model with no dark energy and fully dominated by cold dark matter (CDM) is proposed. The number of CDM particles is not conserved and the present accelerating stage is a consequence of the negative pressure describing the irreversible process of gravitational particle creation. In order to have a transition from a decelerating to an accelerating regime at low redshifts, the matter creation rate proposed here depends on 2 parameters (y and ??): the first one identifies a constant term of the order of H0 and the second one describes a time variation proportional to he Hubble parameter H(t). In this scenario, H0 does not need to be small in order to solve the age problem and the transition happens even if there is no matter creation during the radiation and part of the matter dominated phase (when the ? term is negligible). Like in flat ACDM scenarios, the dimming of distant type Ia supernovae can be fitted with just one free parameter, and the coincidence problem plaguing the models driven by the cosmological constant. ACDM is absent. The limits endowed with with the existence of the quasar APM 08279+5255, located at z = 3:91 and with an estimated ages between 2 and 3 Gyr are also investigated. In the simplest case (? = 0), the model is compatible with the existence of the quasar for y > 0:56 whether the age of the quasar is 2.0 Gyr. For 3 Gyr the limit derived is y > 0:72. New limits for the formation redshift of the quasar are also established / Observa?c~oes astron?micas recentes (envolvendo supernovas do tipo Ia, anisotropias da radia??o c?smica de fundo e aglomerados de gal?xias) sugerem fortemente que o Universo observado ? descrito por um modelo cosmol?gico plano e acelerado, cujas propriedades do espa?o-tempo podem ser representadas pela m?trica de Friedmann-Robertson-Walker (FRW). Entretanto, a natureza ou mecanismo respons?vel pela acelera??o permanece desconhecida e sua determina??o constitui o problema mais candente da Cosmologia moderna. Em cosmologias relativ?sticas, um regime acelerado ? usualmente obtido supondo a exist?ncia de uma componente ex?tica de energia com press?o negativa, denominada energia escura, cuja representa??o te?rica mais simples ? uma constante cosmol?gica ?, usualmente associada com a densidade de energia do v?cuo. Todas as observa??es conhecidas est?o de acordo com o chamado modelo de concordancia c?smica (ACDM). No entanto, tais modelos apresentam v?rios problemas te?ricos e tem inspirado muitos autores a proporem candidatos alternativos para representar a energia escura no contexto relativ?stico. Nesta tese, propomos um novo tipo de modelo plano, acelerado e sem energia escura, que ? completamente dominado pela mat?ria escura fria (CDM). O n?mero de part?culas de mat?ria escura n?o ? conservado e o atual est?gio acelerado ? uma consequ?ncia da press?o negativa descrevendo o processo irrevers?vel de cria??o gravitacional de mat?ria. Para ocorrer uma transi??o de um regime desacelerado para outro acelerado em baixos redshifts, a taxa de cria??o de mat?ria proposta aqui depende de 2 par?metros (y e ?): o primeiro deles identifca um termo constante da ordem de H0 enquanto o segundo especifica uma varia??o proporcional ao parametro de Hubble H(t). Neste cen?rio, H0 n?o precisa ser pequeno para resolver o problema da idade e a transi??o ocorre mesmo quando n?o existe cria??o de mat?ria durante a era da radia??o e parte da era da mat?ria (quando o termo ? ? desprez?vel). Tal como nos modelos ?CDM planos, os dados de supernovas tipo Ia distantes podem ser ajustados com um ?nico par?mero livre. Al?m disso, neste cen?rio n?o h? o problema da coincid?ncia c?smica existente nos modelos dirigidos pela constante cosmol?gica. Os limites oriundos da exist?ncia do quasar APM 08279+5255, localizado em z = 3:91, e com idade estimada entre 2 e 3 bilh?es de anos s?o tamb?m investigados. No caso mais simples (? = 0), o modelo ? compat?vel com a exist?ncia do quasar para y > 0; 56 se a idade do quasar for 2 bilh?es de anos. Para 3 bilh?es de anos o limite obtido ? y > 0; 72. Novos limites para o redshift de forma??o do quasar s?o tamb?m estabelecidos

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2017-09-29T19:13:24Z No. of bitstreams: 2 Dissertação - William Andrés López Arboleda - 2015.pdf: 1579315 bytes, checksum: 378fd0e65f3b2919d56630143950ed75 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-02T13:35:40Z (GMT) No. of bitstreams: 2 Dissertação - William Andrés López Arboleda - 2015.pdf: 1579315 bytes, checksum: 378fd0e65f3b2919d56630143950ed75 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-02T13:35:40Z (GMT). No. of bitstreams: 2 Dissertação - William Andrés López Arboleda - 2015.pdf: 1579315 bytes, checksum: 378fd0e65f3b2919d56630143950ed75 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-03-27 / Sclerotinia sclerotiorum is a phytopathogenic fungus that infects more than 400 plant species, including common bean. Genetic variability studies in connection with phenotypic traits of agronomic interest are important to drive the control strategies against this pathogen. The aims of this study were: to evaluate the genetic variability, fungicide sensitivity, aggressiveness and to determine the proportion of MAT (Mating Type) alleles of 79 isolates of S. sclerotiorum distributed in four populations from common bean. Two populations represented a single sampling location in two different times (2000 and 2013 growing seasons). To evaluate the fungicide sensitivity a cell viability test based on the alamarBlue dye using mycelial growth was standardized. Dose-response curves for fluazinam, procymidone and benomyl were estimated using this test and were compared with dose-response curves estimated by the mycelial growth inhibition on PDA plate and the FRAC (Fungicide Resistance Action Committee) protocol. Despite the differences to assess the fungicide sensitivity between the three methods, the dose-response curves showed similar trends for the three fungicides. The fungicide sensitivity assessment at the four populations showed low sensitivity to benomyl in the Planaltina population. Furthermore, this population presented a principally clonal population structure, with a haplotype represented by 18 out of 20 isolates. Significant population differentiation in all pairwise comparisons of phi, except the comparison between EV_2013-NH, was detected. Five genetically homogeneous groups were inferred by the DAPC analysis. No group was conformed by isolates from the four populations. Only two haplotypes between the two populations from the same sampling location were shared. The hypothesis of random mating was rejected at the four populations; however this hypothesis was not rejected at the two major populations inferred by the DAPC analysis. The screening of mating type locus showed a dominance of Inv+ isolates and a high proportion of Inv+/Inv- isolates (presumable heterokaryons). / Sclerotinia sclerotiorum é um fungo fitopatogênico capaz de colonizar mais de 400 hospedeiras, sendo o agente causal do mofo branco no feijoeiro. Estudos de variabilidade genética associados a características fenotípicas de interesse agronômico, como a sensibilidade a fungicidas, oferecem informações importantes para direcionar estratégias de controle sobre este patógeno. Os objetivos deste trabalho foram avaliar a variabilidade genética, sensibilidade a fungicidas e agressividade de 79 isolados de S. sclerotiorum distribuídos em quatro populações procedentes de culturas de feijoeiro em pivô central. Duas destas populações representaram um único local de coleta em duas épocas diferentes (2000 e 2013). Para avaliar a sensibilidade a fungicidas foi padronizado um teste de viabilidade celular baseado no corante alamarBlue® sobre o crescimento micelial em microplaca de 96 poços. Curvas de dose-resposta para os fungicidas fluazinam, procimidona e benomyl, usando um isolado de S. sclerotiorum, foram estimadas com este método, e comparadas com curvas de dose-resposta obtidas com os métodos de inibição do crescimento em placa e o proposto pelo Fungicide Resistance Action Committee (FRAC). Apesar das diferentes abordagens as curvas dose-resposta mostraram tendências semelhantes para os três fungicidas. A avaliação da sensibilidade a fungicidas nas quatro populações indicou uma alta insensibilidade ao benomyl na população de Planaltina. Por outro lado, a estrutura populacional foi principalmente clonal com um haplótipo representado por 18 dos 20 isolados desta população. Diferenciação populacional significativa foi detectada em todas as comparações par a par do phi, com a exceção da comparação EV-2013-NH. A analise DAPC identificou cinco grupos geneticamente homogêneos. Nenhum dos grupos esteve constituído por isolados das quatro populações. Só dois haplótipos foram compartilhados pelas populações EV_2000 e EV_2013. A hipótese de acasalamento aleatório foi rejeitada nas quatro populações, no entanto não foi rejeitada nas duas maiores populações sugeridas pelo DAPC. O screening do Mating type locus (MAT) mostrou uma prevalência de isolados Inv+ e uma alta proporção de isolados Inv+/Inv-

Denna studie har som syfte att studera vilka tankar förskolebarn i åldern mellan 5-6 år har om energiprocesser kopplat till människokroppen. Metoden var en kvalitativ semistrukturerad intervjustudie som genomfördes på en förskola samt i en förskoleklass. Teoretiska utgångspunkten var social konstruktivism. Intervjuerna kompletterades med en docka som blev ett kommunikativt redskap. Resultatet av studien visar att de flesta barn relatera mat som en viktig energikälla. Barnens tankar om vart de får sin energi ifrån ligger i vardagsspråket, där barnen använder energi begreppet som att känner sig utvilad och har ork för att kunna leka. Den skiljer sig till den naturvetenskapliga betydelsen av energi där vi får vår energi genom cellandningen. Barns tankar om hur de får sin energi skiljer sig och sammanfattas i fem olika kategorier. Kategorierna är: genom mat, genom rörelse, genom vila, genom vätska och genom syre. / The purpose of this study is to investigate how preschool children between the age of 5 and 6 years reflect about energy processes connected to the body. The study was conducted with semi structured interviews with a preschool class and a preschool. The theoretical framework for the study is social constructivism. The study was conducted with communicative tools (a doll). The result of the study is most children relate food as an important source of energy. Children ́s perceptions about where they got the energy from, lies in the form of informal language, where they use the word energy when they feel alert and have strength to play. It differs from the science ́s descriptions of energy, that we obtain energy through cellular respiration. Children ́s perceptions about where they got the energy from are divided into five categories. The categories are: through food, through motion, through rest, through fluid and through oxygen.