Orientadores: Nelma de Mello Silva Oliveira, Gisela de Aragão Umbuzeiro, Simone Valente Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-27T02:06:39Z (GMT). No. of bitstreams: 1 Resende_MariellyReis_M.pdf: 1924615 bytes, checksum: 1591718b0b86c23e64a29629b4589246 (MD5) Previous issue date: 2015 / Resumo: Embora tenha grande utilidade e diversas aplicações nos setores industriais, há anos a discussão sobre o potencial genotóxico do corante tartrazina vem sendo abordada, uma vez que há vários resultados controversos descritos na literatura. É provável que a presença de impurezas nas amostras possa ser uma das causas do possível potencial mutagênico. Dessa forma, esse estudo visa avaliar a atividade mutagênica do corante tartrazina com diferentes graus de pureza e possíveis interferentes presentes nas amostras, utilizando o ensaio Salmonella/microssoma a partir das linhagens recomendadas pela OECD 471. Os resultados obtidos demonstraram que o corante tartrazina ?99 % e o corante tartrazina comercial 90%, não apresentaram atividade mutagênica para as linhagens TA97a, TA98, TA100, TA1535 e TA102 demonstrando ausência de impurezas mutagênicas ou que as mesmas estejam em baixas concentrações nas amostras avaliadas / Abstract: Although very useful and diverse applications in industry, for years the discussion on the genotoxic potential of the dye tartrazine has been addressed, since there are several controversial results in the literature. It is likely that the presence of impurities in the samples may be a cause of the possible mutagenic potential. Thus, this study aims to evaluate the mutagenic activity of the dye tartrazine with different degrees of purity and possible interferences present in the samples, using the Salmonella / microsome test from the lines recommended by the OECD 471. The results showed that the dye tartrazine ?99 % and the dye tartrazine commercial 90% showed no mutagenic activity for the strains TA97, TA98, TA100, TA1535 and TA102 showing absence of mutagenic impurities or that they are in low concentrations in the analyzed samples / Mestrado / Tecnologia e Inovação / Mestra em Tecnologia

Diploma thesis introduces the problems of electromigration, fluxes and flux residues. It includes a proposal for methods of measuring surface insulation resistance, information about selected types of fluxes and conformal coatings. It focuses on the influence of temperature, humidity. There are applied conductometric method and method of measuring SIR by IPC-25-B. The thesis describes the practical measurement of SIR and ionic contamination of PCB covered with flux and influence of RH, temperature and applied voltage is evaluated and discussed.

Parmi les nouveaux matériaux massifs pour le silicium photovoltaïque (PV), le silicium multicristallin haute performance (HPmc-Si) a émergé en raison de son rendement de conversion supérieur à celui du silicium multi-cristallin (mc-Si) utilisé largement pour le solaire PV. Ce travail de recherche vise à comprendre l'influence des germes et des conditions de croissance sur les lingots HPmc-Si (structure de grains, dislocations, impuretés et propriétés PV). Cinq lingots ont été élaborés par solidification dirigée. Pour l’un d’entre eux, deux types de germes ont été utilisés. Les caractéristiques de la région de croissance initiale (jusqu’à 50 mm) sont directement liées aux propriétés de la couche de germes. Or, celle-ci dépend à la fois des types de germes utilisés et des paramètres de l’étape de fusion. Les paramètres de croissance prennent le contrôle de la structure de grains après la région affectée par la couche initiale de germes. Cependant, les paramètres de croissance étudiés modifient peu les caractéristiques entre lingots HPmc-Si et le rendement de conversion des cellules solaires. Les zones de faible durée de vie des porteurs minoritaires déterminent le rendement de conversion et peuvent être principalement associées aux défauts structuraux et à la taille du grain, en plus des impuretés métalliques. La compétition des grains est un phénomène dynamique qui permet la disparition de certains grains défectueux pendant la croissance et surtout le maintien d’une taille de grains et homogène. Cette homogénéité obtenue pour la gamme de paramètres étudiée est une des caractéristiques principales des lingots HPmc-Si / Among new bulk silicon PV materials, HPmc-Si is one to be considered due its higher conversion efficiency compared to mc-Si solar PV. This research work aims at understanding the influence of the seeding materials and growth conditions on HPmc-Si ingots (dislocations and impurities). Five ingots were grown, and two types of seeding materials are compared to study the grain structure, the electrical properties and the conversion efficiency of solar cells. The initial growth region up to 50 mm is directly linked to the seed layer properties which are dependent on the melting segment parameters. The growth parameters take control on the grain structure after the seed affected region. The growth parameters studied modify little the characteristics of HPmc-Si ingots and the solar cell conversion efficiency. Low carrier lifetimeareas determine the conversion efficiency and they can mainly be associated to the grain size, besides metallic impurities. The grain competition is very dynamic to suppress defective grains and to maintain smaller grain size variation, homogeneous grain size and properties being the most important characteristic of HPmc-Si ingots

In this thesis, we summarize the material-specific theories of strongly correlated systems and apply them to selected materials. We describe and apply the corre- lated band theory methods: the local density approximation plus Coulomb U, and the density functional theory plus exact diagonalization of single impurity An- derson model. First, we investigate the systems containing impurity atoms: cobalt impurity located in the bulk copper and samarium, and neodymium adatoms on the surface of graphene. We present the spectral densities and study the magnetism of those compounds. Afterwards, we analyze three Np-based compounds: NpPt2In7, Np2Ni17 and NpBC. For all three compounds we analyze the spin, orbital and to- tal magnetic moments and the total density of states, as well as its projections for selected orbitals and spins. Moreover, for NpPt2In7 and NpBC we perform the to- tal energy analysis between different magnetic moment arrangements on the Np atoms.

In order to study the electronic and optical properties of complex materials an approach providing a reliable estimate of band gaps in combination with the reasonable description of the ground state is required. In the present study of pure and defective perovskite crystals, the fulfillment of such requirements is clearly demonstrated using a simple hybrid HF/DFT scheme containing an admixture of non-local Fock exchange. In present theoretical investigations, a wide class of perovskite oxides is represented by three, the most attractive (from a scientific point of view) crystals of SrTiO3, BaTiO3, and PbTiO3 in their high symmetry cubic phases. These perovskite crystals present a great technological and fundamental interest due to their numerous applications related to ferroelectricity, non-linear and electro-optics, superconductivity, and catalysis. Although the above-mentioned perovskite-type materials have been intensively investigated theoretically and experimentally at least in the last fifteen years, a proper description of their electronic properties is still an area of active research. In order to make a contribution to the explanation of various electro-optical effects observed in perovskite materials, their ground-state properties have been calculated from first principles and analyzed in the present study.

Aluminium has great properties that are utilised the world over, but the production of primary aluminium is very energy intensive. In order to reduce the energy-cost, the aluminium can be recycled by re-melting aluminium scrap. This results in a circularity of the aluminium, as it is produced from ore to a metal and then the metal scrap can be re-melted again for other use.  The study also focuses on secondary production in Sweden. Through interviewing diverse actors in Sweden and analysing literature, an understanding of how the circulatory systems work was developed and the problems that can occur within it.  The major problems found is that through re-melting, the previous alloying elements can become impurities in the new scrap-based material. These impurities can change the properties in the aluminium. Separating these impurities from the aluminium is not an easy process, but a growing research question. Easiest is to minimise these contaminations, companies do this by sourcing where scrap is coming from and its compositional information, so to better organize or use the scrap for a similar purpose aluminium alloy.  This study looked at how the circulation of aluminium scrap works and how used scrap is once again returned to new reusable aluminium. With an understanding of how the processes it is easier to locate problems to improve the processes. / Aluminium har mycket goda mekaniska egenskaper som används i hela världen, men att producera primär aluminium är extremt energikrävande. För att minska energikostnaden kan man återvinna aluminiumet, det görs genom att återanvända gammalt aluminiumskrot. När man gör detta så leder det till ett cirkulärt kretslopp, där det börjar från malm som produceras till metall, när metallen blir till skrot så kan det återanvändas för att producera nytt aluminium.  Genom att intervjua folk inom branschen och att analysera litteratur inom ämnet, så skapades en förståelse hur det cirkulär kretsloppet fungerar och problem som kan uppstå inom systemet.  Det största problemet som hittades var att genom att återvinna aluminium skrot, så kan det tidigare legeringselement bli föroreningar i den nya skrot baserade materialet. Dessa föroreningarna kan ändra egenskaperna hos aluminiumet. För att får bort dessa föroreningar kan vara en svår process eller fortfarande utvecklande processen. Det är mycket lättare att försöka undvika dessa föroreningarnas från börja. Företagen gör detta genom att veta var skrotet kommer ifrån och skrotets legeringsämnen innan de återanvänder det. Då kan de organisera skrotet bättre och använda det till liknande skrot material i framtiden.  Denna studien fokuserar på hur skrotbaserat aluminium fungerar i ett kretslopp och hur gammalt skrot kan återanvändas till ny användbar aluminium. Med en förståelse på hur processen fungerar, så är det mycket lättare att hitta problem som kan leda till möjligheter att förbättra processen.

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<p>U okviru ove doktorske disertacije ispitani su i utvrđeni optimalni uslovi za proces lju&scaron;tenja semena suncokreta visokooleinskog tipa, kao sirovine za proizvodnju ulja. Sprovedena istraživanja su dala podatke o optimalnim vrednostima sadržaja vlage u semenu i pritiska vazduha u lju&scaron;tilici na osnovu kojih je utvrđen model za lju&scaron;tenje semena. Sprovedenim istraživanjima obuhvaćeno je i ispitivanje uticaja promenljivih tehnolo&scaron;kih parametara, sadržaja ljuske u opsegu od 0 do 20% i sadržaja nečistoća u opsegu od 0 do 10% na sastav i kvalitet hladno presovanih ulja i pogače, prinos ulja, oksidativnu stabilnost, senzorski kvalitet i boju hladno presovanih ulja semena suncokreta visokooleinskog tipa.<br />Dobijeni rezultati su obrađeni primenom savremenih klasifikacionih (klaster analiza i analiza glavnih kompomenata) i regresionih hemometrijskih metoda i postavljeni hemometrijski modeli čija bi primena doprinela proizvodnji hladno presovanog ulja vrhunskog kvaliteta i visoke oksidativne stabilnosti. Utvrđeno je da su definisani modeli statistički validni i da se mogu primeniti za optimizaciju tehnolo&scaron;kih parametara u proizvodnji hladno presovanog ulja semena suncokreta visokooleinskog tipa. Validnost postavljenih modela, odnosno kvalitet dobijenih korelacija su procenjeni na osnovu parametara unakrsne validacije.<br />Maksimalna efektivnost lju&scaron;tenja semena suncokreta visokooleinskog tipa može se postići pri optimalnim uslovima tj. sadržaju vlage u semenu 6,0% i pritisku vazduha u lju&scaron;tilici 800 kPa. Hladno presovano ulje semena suncokreta visokooleinskog tipa se, u pogledu sastava i kvaliteta ulja i pogače, prinosa ulja, oksidativne stabilnosti, senzorskog kvaliteta i boje ulja, može proizvoditi od semena koje sadrži 10-20% ljuske i 0-5% nečistoća.</p> / <p>In this dissertation the optimal conditions for the dehulling process of high-oleic sunflower seeds, as raw material for oil production, were tested and determined. The conducted studies provided data for the optimal values of moisture content in the seed and the air pressure in the seed dehulling machine, what presented the base for determination of the dehulling model. Also, conducted studies examine the effect of variable technological parameters, such as content of hull (ranging from 0 to 20%) and the impurities content (ranging from 0 to 10%) on the composition and quality of oil and cake, oil yield, oxidative stability, sensory quality and colour of cold pressed high-oleic sunflower oil.<br />The obtained results were analyzed by modern classification (cluster analysis and principal component analysis) and regression chemometrics methods, and chemometric models whose implementation could contribute to the production of cold pressed oil of high quality and high oxidative stability were set. It was found that the defined mathematical models are statistically valid and that they could be used to optimize the technological parameters of production of cold pressed high-oleic sunflower oil. The validity of the set models, that is the quality of obtained correlations, were estimated based on the parameters of cross-validation.<br />The maximum effectiveness of high-oleic sunflower seeds dehulling can be achieved under optimal conditions, i.e. when the moisture content in seed is 6,0% and when the air pressure in seed dehulling machine is 800 kPa. Regarding composition and quality of the oil and cake, oil yield, oxidative stability, sensory quality and color, cold pressed high-oleic sunflower oil could be produced from seed containing 10-20% hull and 0-5% impurities.</p>

Les conditions pour la fusion DT peuvent-être obtenues dans les tokamaks. Dans ces machines, l'interaction plasma-paroi et l'extraction de puissance sont gérées dans une cavité appelée divertor. Toutefois, les hautes puissances impliquées et les limitations des composants face au plasma (CFP) sont problématiques. Ce domaine fait l'objet de nombreuses recherches dans le contexte de ITER qui doit démontrer 500 MW de puissance fusion durant 400 s. Ces opérations nécessitent sur la réduction des flux de chaleur sur les CFP à un niveau gérable et repose sur le détachement du plasma dans le divertor qui implique la décroissance des flux de particules et de chaleur. Malheureusement, ce processus demeure difficile à modéliser. Le but the ce doctorat est d'utiliser la modélisation d'expériences de JET avec EDGE2D-EIRENE pour faire des progrès dans la compréhension du détachement. Les simulations reproduisent le détachement observé en environnement C comme Be/W. La distribution du rayonnement est reproduite par le code en C mais des écarts subsistent en Be/W. La comparaison entre différents processus de physique atomique montre que les collisions élastiques ion-molécule sont responsables du détachement. Ce processus permet le confinement des neutres dans le divertor ainsi que des pertes de moments significatives à basse température lorsque le plasma est recombinant. La comparaison entre EDGE2D-EIRENE et SOLPS4.3 montre des tendances similaires pour le détachement. Les deux codes suggèrent que tout processus capable d'améliorer le confinement des neutres dans le divertor devrait faciliter la modélisation du détachement. / The conditions required for fusion can be obtained in tokamaks. In most of these machines, the plasma wall-interaction and the exhaust of heating power are handled in a cavity called divertor. However, the high heat flux involved and the limitations of the materials of the plasma facing components (PFC) are problematic. Many researches are done this field in the context of ITER which should demonstrate 500 MW of DT fusion power during ~ 400 s. Such operations could bring the heat flux on the PFC too high to be handled. Its reduction to manageable levels relies on the divertor detachment involving the reduction of the particle and heat fluxes on the PFC. Unfortunately, this phenomenon is still difficult to model. The aim of this PhD is to use the modelling of JET experiments with EDGE2D-EIRENE to make some progress in the understanding of the detachment. The simulations reproduce the observed detachment in C and Be/W environments. The distribution of the radiation is well reproduced by the code for C but with some discrepancies in Be/W. The comparison between different sets of atomic physics processes shows that ion-molecule elastic collisions are responsible for the detachment seen in EDGE2D-EIRENE. This process provides good neutral confinement in the divertor and significant momentum losses at low temperature, when the plasma is recombining. Comparison between EDGE2D-EIRENE and SOLPS4.3 shows similar detachment trends but the importance of the ion-molecule elastic collisions is reduced in SOLPS4.3. Both codes suggest that any process capable of improving the neutral confinement in the divertor should help to improve the modelling of the detachment.