Due to the growing concern for the environment, several Technologies for treatment of industrial effluents are being developed in order to minimize the impacts on water resources. Amid the various studied technologies, Advanced Oxidations Processes (AOPs) have received attention considerable. Among AOPs, the Fenton reaction, as source of generation hydroxyl radicals, has been outstanding. The Fenton reaction is the catalytic process of decomposition of hydrogen peroxide (H2O2) by ferrous ion (Fe2+) generating hydroxyl radicals, (HO•). The hydroxyl radical has a high oxidizing power, which leads to a partial or total degradation of large number of pollutants compounds. The ferrous ion, in appropriate pH, has the coagulant properties and may contribute to the removal of suspended particles in solution. The efficiency of the Fenton reaction can be enhanced when combined with the settling process. Depending of effluent, the sedimentation may be a slow step that can to reduce the application process on an industrial scale. The use of settler can accelerate the process, allowing the use of the method and also in continuous flow and also the use of iron concentrations higher, increasing the efficiency of treatment. In this study it was evaluated the efficiency of the coagulation processes, Fenton / flocculation, and coagulation followed by Fenton / flocculation in the treatment of effluents from the paints industries. In this study also was projected a lamellar settler to accelerate the sedimentation process. The results confirmed the efficiency of Fenton reaction followed by coagulation / flocculation in the treatment of real effluent of paint industry. The treatment led to a reduction of approximately 95% of COD of effluent, it suitable for disposal. Applying the same technology, using the settler in the sedimentation processes, the efficiency of COD reduction was the same, however, the treatment time was about eight times lower. The application of the Fenton reaction followed by sedimentation trough the lamellar settling led to a reduction of 95% of COD of effluent. The system Fenton / flocculation with lamellar settler was the process more promising, due using of lower concentrations of reactants. The process can be applied in the treatment of industrial effluent, with advantages over conventional methods. / Em função da crescente preocupação com o meio ambiente diversas tecnologias de tratamento de efluentes industriais estão sendo desenvolvidas, visando minimizar os impactos gerados sobre os recursos hídricos. Em meio às diversas tecnologias estudadas, os Processos Oxidativos Avançados (POAs) têm recebido considerável atenção. Dentre os POAs a utilização da reação de Fenton como fonte geradora de radical hidroxila tem se destacado. A reação de Fenton consiste no processo catalítico de decomposição do peróxido de hidrogênio (H2O2) pelo íon ferroso (Fe2+) gerando os radicais hidroxila (HO•). Os radicais hidroxilas têm alto poder de oxidação, o que leva a uma degradação parcial ou total de inúmeros compostos poluentes. O íon ferroso, em pH apropriado, apresenta propriedades coagulante, podendo contribuir com a remoção de partículas suspensas em solução. A eficiência da reação de Fenton pode ser ampliada quando associada ao processo de sedimentação. Dependendo do efluente tratado, a sedimentação pode ser uma etapa lenta que pode prejudicar a aplicação do processo em escala industrial. A utilização de sedimentadores pode acelerar o processo, permitindo a utilização do método em regime continuo e também trabalhar com altas concentrações de ferro, aumentando a eficiência do tratamento. Neste estudo buscou-se avaliar a eficiência dos processos de coagulação, Fenton /Floculação, e coagulação seguida de Fenton / Floculação no tratamento de efluentes oriundos da indústria de tintas. Também empregou-se um sedimentador lamelar tubular para acelerar o processo de sedimentação.Os resultados comprovaram a eficiência da coagulação seguida de Fenton / Floculação no tratamento de um efluente real de uma indústria de tinta local. O tratamento levou a redução de aproximadamente 95% da DQO do efluente, adequando-o para descarte. Aplicando-se a mesma tecnologia, utilizando o sedimentador lamelar nos processos de sedimentação, a eficiência para a redução da DQO foi basicamente a mesma, no entanto, o tempo d o tratamento foi aproximadamente oito vezes menor. A aplicação da reação de Fenton seguida de sedimentação através do sedimentador lamelar levou a redução de 95% da DQO do efluente. Dos processos estudados o sistema Fenton / Floculação com sedimentador lamelar foi o mais promissor, pois, utilizou menores concentrações dos reagentes, podendo ser aplicado no tratamento do efluente industrial, com vantagens frente aos métodos convencionais utilizados.

Dans les sédiments marins, la conversion de l'azote en diazote est traditionnellement supposée avoir lieu via le processus de nitrification-dénitrification bactérienne ou par l'oxydation anaérobie de l'ammonium (anammox). Mais, les faibles concentrations d'ammonium observées dans les sédiments riches en oxyde de manganèse suggèrent l'existence d'une voie alternative qui pourrait avoir lieu via un processus chimique. Parmi les oxydes de manganèse, la birnessite est la forme la plus existante dans les sols et les sédiments. C'est un oxyde lamellaire contenant à la fois du Mn (III) et du Mn (IV) dans sa structure et caractérisé par sa haute réactivité. Ce travail vise à mettre en évidence la nature de la réactivité de la Na-birnessite triclinique synthétisée par une méthode redox avec l'ammonium. Cette interaction était soupçonnée, dans des études antérieures, d'impliquer un mécanisme d'échange cationique seulement. La première partie de ce manuscrit est consacrée à la synthèse d'une birnessite pure via un processus redox. Le rapport Mn (VII): Mn (II) de 0,33 a été choisi et trois méthodes ont été utilisées consistant en un mélange rapide sous agitation vigoureuse de deux des trois réactifs et ensuite en l’ajout goutte à goutte du troisième. L'étude de paramètres réactionnels (ordre de mélange des réactifs, temps d'addition du troisième réactif, méthode de vieillissement, nature du cation utilisé et présence ou absence de l'oxygène dissous) a mis en évidence le rôle clé de l'oxygène dans la formation de la birnessite pure et un mécanisme de formation a été proposé. La deuxième partie a porté sur l'interaction de la Na-birnessite avec l'ammonium. L'étude de nombreux paramètres réactionnels (concentration initiale en ammonium, temps de contact, pH et température du milieu), en suivant à la fois les changements solides et liquides, a permis de démontrer que la birnessite n'agit pas seulement comme échangeuse cationique envers NH4+. En effet, l'analyse de surface réalisée par XPS a montré que les spectres N1s sont caractérisés par l'existence de deux environnements différents : un attribuable à NH4+ dans le domaine interfoliaire et le second à une espèce N chimisorbée. Des transformations structurales et chimiques ont été observées sur la birnessite avec un déficit de bilan massique d'azote. L’analyse des espèces en solution : NH4+, Na+, Mn2+, NO3- et NO2- et solides (état d'oxydation moyen de Mn, capacité d'échange cationique, teneur en azote solide et évolution de symétrie identifiée par DRX et FTIR) indique sans ambiguïté que NH4+ réagit chimiquement avec la birnessite / In marine and sediments, the conversion of combined nitrogen to dinitrogen is traditionally assumed to take place via the coupled bacterial nitrification-denitrification process or through the anaerobic ammonium oxidation (anammox). But, the low ammonium concentrations observed in the Mn-oxide rich sediments suggested the existence of an alternative pathway that might take place via a chemical process. Among manganese oxide, birnessite was found to be the most existing form in soils and sediments. It is a lamellar oxide containing both Mn(III) and Mn(IV) in its structure and characterized by its high reactivity. This work aims to highlight the nature of the reactivity of the triclinic Na-birnessite synthesized via a redox method with ammonium. This interaction was suspected, in previous studies, to involve a cationic exchange mechanism only. The first part of this manuscript is dedicated to the synthesis of a pure phase birnessite via a redox process. The Mn(VII):Mn(II) ratio of 0.33 was chosen and three methods were used consisting in a quick mixing under vigorous stirring of two of the three reagents and then on the dropwise addition of the third one. The study of numerous reaction parameters (the order of reagent mixing, the addition time of the third reagent, the aging method, the nature of the cation used and the dissolved oxygen effect) highlighted the key role played by oxygen in the formation of a pure birnessite and a mechanism of formation has been proposed. The second part focused on the interaction of Na-birnessite with ammonium. The study of numerous reaction parameters (the initial ammonium concentration, the contact time, the pH and the temperature of the medium) by monitoring both solid and liquid changes allowed us to demonstrate that birnessite is not only acting as a cationic exchanger toward NH4+. Indeed, the surface analysis performed by XPS showed that N1s spectra are characterized by the existence of two different environments: one assignable to an interlayer NH4+ and the second to a chemisorbed N-species. Structural and chemical transformations were observed on birnessite with nitrogen mass balance deficit. The monitoring of NH4+, Na+, Mn2+, NO3- and NO2- and solid changes (average oxidation state of Mn, cation exchange capacity, solid nitrogen content and symmetry evolution identified by XRD and FTIR) indicate unambiguously that NH4+ reacts chemically with the birnessite

Made available in DSpace on 2014-06-11T19:23:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-24Bitstream added on 2014-06-13T19:09:50Z : No. of bitstreams: 1 macedo_lr_me_jabo.pdf: 704711 bytes, checksum: 5b7cb390daed7f40913d5a7cfd9176c2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Avaliaram-se descritivamente, à clínica, à histopatologia e à imunoistoquímica (ki 67- marcador de proliferação celular) os resultados, da cicatrização da córnea, após ceratoplastias lamelares com membrana de celulose microfibrilar em coelhos. Para tal, utilizaram-se 30 coelhos , distribuídos em 5 grupos de 6 animais, avaliados por até 60 dias de pós operatório. A avaliação clínica revelou manifestações moderadas de edema, blefaroespasmos, fotofobia desde o segundo dia, evoluindo para formas discretas ou ausentes a partir do sétimo dia, onde observou-se clinicamente o reparo do defeito da córnea. A histopatologia revelou uma fina camada de células escamosas, recobrindo totalmente a área lesada, aos sete dias, e com leve infiltrado de células polimorfonucleares. Observou-se a presença de vasos no epitélio a partir do 15º dia , com regressão aos 48º dias .A imunoistoquímica mostrou aumento de células em proliferação aos 15 dias no epitélio (p= 0,049) e aos trinta dias no estroma (p= 0,042). Frente aos resultados obtidos, há como admitir que mesmo com o defeito corneal concluído, aos sete dias, o sistema de defesa celular ainda se manteve ativo, pois a proliferação celular no epitélio se mostrou mais intensa aos 15 dias de observação ,conforme demonstrado imunoistoquimicamente. Onde nesse período ocorreu remodelamento e adesão epitelial da córnea, características satisfatórias em ceratoplastia lamelar em coelhos . / Were evaluated the clinic, the histopathology and immunohistochemistry (ki 67 - marker of cell proliferation), the results of the membrane of cellulose in lamellar keratoplasty in rabbits. To this end, 30 rabbits were used, divided into 5 groups of 6 animals, assessed by up to 60 days of post-operative. The assessment showed clinical manifestations of moderate swelling, blefarospasmos, photophobia since the second day, evolving into discrete forms or absent from the seventh day, where there was clinically repair the defect of the cornea. The histopathology revealed a thin layer of squamous cells, completely covering the injured area, the seven days, and with mild infiltration of polymorphonuclear cells. There was the presence of vessels in the epithelium from the 15 th day, with regression of days to 48. Immunohistochemistry showed increased cell proliferation in the 15 days in the epithelium (p = 0049) and the thirty days in the stroma (p = 0042) . Facing the results achieved, as there admit that even with the beginning of healing, and with the defect of the cornea closed to seven days, the system of defence cell remained active, as in the epithelial cell proliferation was more intense at 15 days, as shown imunoistochemistry. Where in that period showed epithelial remodeling and membership, characteristics satisfactory in lamellar keratoplasty in rabbits.

Introduction: Recent advances in posterior lamellar keratoplasty necessitated the preparation of posterior corneal lamellae even in the Czech Republic. The aim of this work was to introduce and standardize a novel method of manual preparation of corneal lamellae for Descemet Membrane Endothelial Keratoplasty with a Stromal rim (DMEK-S) in an ocular tissue bank. After setting the criteria for endothelial quality, we obtained a licence to provide the tissues for transplantation purposes. The obtained results were analysed after two years. Furthermore, a novel lamellar insertion technique using a cartridge was assessed. The potentials for the long-term storage of posterior corneal lamellae by the vitrification in liquid ethane was studied using human amniotic membrane as a model tissue. Material and Methods: Corneoscleral buttons stored in tissue cultures were used to prepare lamellae consisting of a central zone of endothelium and Descemet membrane supported by a stromal rim at the periphery. The manual preparation was performed on an artificial anterior chamber using the big bubble technique. Endothelial quality was assessed before storage, before and immediately after preparation as well as after 2 days of storage at 31řC. A group of 12 corneas with a live endothelial cell density ≥ 2500 cells/mm2...

Compostos lamelares do tipo da hidrotalcita ou hidróxidos duplos lamelares (HDL), são materiais que possuem notáveis propriedades estruturais, químicas, eletrônicas, iônicas, ópticas e magnéticas. Em função dessas propriedades, os HDL apresentam uma diversidade de aplicações tais como adsorventes e catalisadores. Este trabalho tem por objetivo utilizar polímeros e macromoléculas na preparação e caracterização de HDL, visando melhorar as propriedades texturais dos HDL de MgAl-CO3 preparados em meio contendo polímeros orgânicos ou a intercalação direta de dendrímeros tipo PAMAM de gerações -0,5 e +0,5 em HDL do sistema Zn/Al. Os HDL de MgAl-CO3 foram preparados pela adaptação do método de coprecipitação a pH decrescente, com a presença de polímeros solubilizados no meio, como molde. Os materiais foram caracterizados por difração de Raios X, análise termogravimétrica, espectroscopia no infravermelho e medidas de área superficial por BET. Baseando-se nos resultados obtidos, pode-se concluir que propriedades texturais dos HDL preparados são modificadas, quando na presença de alguns polímeros. Na maioria dos casos, os valores calculados de área superficial específica foram mais elevados, em comparação com aquele obtido para o HDL preparado em meio reacional sem polímero. Isto pode ser explicado pela diminuição do tamanho de partículas e aumento no diâmetro médio de poros dos materiais preparados, provocada pela presença de polímeros no meio reacional. Os HDL intercalados com dendrímeros PAMAM G-0,5 e PAMAM G+0,5 foram preparados por duas rotas diferentes: coprecipitação a pH constante e troca iônica em fase dupla. Os materiais obtidos foram caracterizados por meio de difração de Raios X, análise de termogravimétrica associada à espectrometria de massas e espectroscopia no infravermelho. Utilizando os dois procedimentos de preparação, a intercalação de PAMAM G-0,5 deu origem a HDL com os mesmos espaçamentos basais, concordando com a intercalação dos ânions do dendrímero em um arranjo perpendicular à lamela do HDL, enquanto que para a intercalação do PAMAM G+0,5, espaçamentos basais muito menores do que o tamanho da molécula foram obtidos. A diferença entre a distância interlamelar observada e a esperada pode ser explicada por um arranjo peculiar das moléculas desse dendrímero em uma forma elipsoidal, devido às interações intramoleculares. Espectros no infravermelho confirmam a presença dos dendrímeros nos materiais Zn2Al-PAMAM G-0,5 e Zn2Al-PAMAM G+0,5. Finalmente, a presença destes dendrímeros foi confirmada por análise térmica associada com espectrometria de massas. Os estudos de Raios X com variação de temperatura in situ e as análises termogravimétricas revelaram que o material obtido pela intercalação do PAMAM G+0,5 é termicamente menos estável do que aquele intercalado com PAMAM G-0,5, concordando com a diferença de estabilidade entre os dendrímeros livres. / Hydrotalcite-like lamellar compounds or layered double hydroxides (LDH) are materials that present notable structural, chemical, electronic, ionic, optical and magnetic properties. Depending on these properties, the LDH present a great variety of applications such as adsorbents and catalysts. The aim of this work is to prepare and to characterize MgAl-CO3-LDH prepared in aqueous media containing organic polymer to improve textural properties, and to prepare HDL by intercalation of dendrimer (PAMAM) of generations -0.5 and +0.5 in ZnAl-HDL. MgAl-CO3-HDL samples were prepared by an adaptation of the coprecipitation method at decreasing pH, with the presence of polymers in the aqueous media as template. The materials were characterized by powder X-ray diffraction, termogravimetric analysis, infrared spectroscopy and BET isotherms. Based on the obtained results, it can be concluded that the textural properties of the prepared LDH were modified. The calculated values of specific surface area were higher in most of the cases compared with those obtained by the LDH prepared without polymer due to a decrease of the particle size and an increase in the average pore diameter of the prepared materials due to the presence of polymers. HDL with intercalated (PAMAM) dendrimers G-0.5 and G+0.5 were prepared by two different methods: coprecipitation at constant pH, and ionic exchange in double phase. The obtained materials were characterized by powder X-ray diffraction, thermal gravimetric analysis associated with mass spectrometry, and infrared spectroscopy. X-ray powder diffraction patterns exhibit the characteristic profiles of the lamellar materials with basal spacing depending on the nature of the dendrimer. For both preparation methods, the intercalation of PAMAM G-0.5 gives rise to LDH with basal spacing in agreement with the dendrimer molecules perpendicular to the layer of the host structure, while for PAMAM G+0.5 a basal spacing smaller than the molecule size was obtained. The difference between the obtained and the expected value is explained by an accommodation of the dendrimer molecule in an ellipsoidal shape, due to the intra-molecular interactions. Infrared spectra confirm the presence of dendrimers in the Zn2Al-PAMAM G-0.5 and Zn2Al-PAMAM G+0.5 materials. Finally, thermal analyses associated with mass spectrometry confirm the presence of these dendrimers. Powder X-ray diffraction with in situ temperature variation reveals that the material obtained by the PAMAM G+0.5 intercalation is thermally less stable than that prepared by PAMAM G-0.5 intercalation, in agreement with the difference in the thermal stability of the free dendrimers.

O objetivo desta pesquisa foi desenvolver e aperfeiçoar uma formulação com fase gel lamelar contendo óleo de Calendula officinalis e avaliar seu potencial na atividade cicatrizante de úlceras em ratos. A formulação estudada possui valor de EHL 6,0, constituída por óleo de calêndula e sistema tensoativo formado por derivados etoxilados dos alcoóis cetílico e estearílico (Ceteth 2/Steareth 20). Primeiramente, determinou-se a região do diagrama ternário de fases em que se encontravam as emulsões com fase gel lamelares (EFGL), macroscopicamente estáveis. Em seguida foi avaliada a estabilidade do sistema e parâmetros que poderiam influenciar na formação das estruturas anisotrópicas. Avaliou-se o comportamento das emulsões utilizando o teste de perda de massa por evaporação. Na avaliação in vitro, foram realizados testes de citotoxidade do óleo de calêndula frente às células de fibroblastos da linhagem L929 através do ensaio de apoptose e necrose. O teste in vivo foi realizado através do Índice de Cicatrização de Úlceras (ICU) no modelo em dorso de ratos (úlcera excisional contrátil) a fim de avaliar o potencial cicatrizante da emulsão proposta comparando com o sham (grupo controle). As úlceras foram avaliadas mediante análise de imagem nos tempos de 0, 2, 7, 14 e 21 dias após o procedimento cirúrgico. A EFGL demonstrou maior estabilidade frente aos testes de estabilidade preliminar e acelerada em relação as demais formulações. Além disso, esta formulação demonstrou menor área de histerese (tixotropia), portanto menor grau de espalhabilidade e com maior tempo de contato com a úlcera. Durante a evaporação das emulsões houve manutenção das estruturas anisotrópicas O óleo bruto da Calendula officinalis não apresentou interferência na via da apoptose e necrose na concentração de até 1000 ?g/mL em fibroblastos L929. A formulação proposta promoveu melhor cicatrização no modelo de úlcera cutânea (ICU) na região dorsal de ratos, supondo- se modular a fase inflamatória do processo de cicatrização, pois o maior recrutamento de células inflamatórias bem como a colagênese, diminuída no grupo EFGL, foram fatores essenciais que permitiram a total reepitelização das úlceras cutâneas. Portanto, pode-se concluir que a metodologia utilizada nesta pesquisa foi útil para a obtenção de emulsões com fase gel lamelar, sendo que a formação dessa estrutura é importante para a estabilidade do sistema, podendo ser utilizada como uma formulação viável e eficaz no processo cicatricial de feridas. / The aim of this research was to improve a lamellar gel phase emulsion containing Calendula officinalis oil and to investigate its potential as a modern wound dressing. First, we determined the region of the ternary phase diagram in which the emulsions were stable and we also evaluated the intrinsic stability of the system and the action of some parameters which may influence the formation of lamellar gel phase. In addition, we analyzed the samples\' behavior during the evaporation process. Moreover, an in vitro cytotoxicity assay of the calendula oil was performed in order to evaluate apoptosis and necrosis in fibroblast cell line L929. Then, an in vivo test was carried out by the wound healing rate (WHR), using a specific model of ulcer in rats (excisional contractile ulcer), in order to assess potential healing of the proposed emulsion (LGP) by comparing with the sham group. The ulcers were evaluated by image analysis at 0, 2, 7, 14 and 21 days after surgery. The emulsion 6 \'showed greater stability in the preliminary and accelerated stability tests in relation to the previous studied formulation. Moreover, this formulation presented more compatible characteristics, because it showed smaller hysteresis area of ? (thixotropy), therefore a lower degree of spreadability and, accordingly, the formulation may increase contact span with ulcer, which is a desirable characteristic. During evaporation of the emulsions, the anisotropic structures were maintained, but their type varied depending on the decreased amount of water in the system. The crude oil of Calendula officinalis showed no interference with the pathway of apoptosis and necrosis in the concentration of 1000 mg / mL in L929 fibroblasts. The proposed model has promoted better wound healing rate in the ulcers in the dorsal region of rats. It seemed to modulate the inflammatory phase of the healing process, because of the increased recruitment of inflammatory cells as well as collagenesis, once LGP emulsion decreased in the group, were factors essential that allowed total reepithelialization of skin ulcers in rats treated with LGP emulsion. In conclusion, this study produced an enhanced and useful LGP which can be used as a new approach to stimulate the healing process and treat wounds efficiently.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22003号 / 医博第4517号 / 新制||医||1038(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長船 健二, 教授 川口 義弥, 教授 柳田 素子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Block copolymers, long chain molecules of two distinct chemical species joined covalently to one another, have long been known to form organized structures on the nanoscopic level. For example, if the two chains are the same length a lamellar structure results . In this work we show how this internal structure causes distinct deviation from 'normal' fluid behavior. We begin with the observation of block copolymer droplets with atomic force microscopy. We note the droplets form nearly conical shapes in stark contrast to the usual spherical cap. These droplets are found t o spread at an incredibly slow speed, and to have interesting instabilities in their wetting layer. We move on to studies of completely wet substrates (i.e. thin films) near the order-disorder transition of the material. Here we directly observe, with optical microscopy, a change in the fundamental spacing of the diblock's internal structure. This represents a superior method of measurement of the Flory-Huggins interaction parameter, which we verify in several ways. We also use the change in lamellar thickness to drive diffusion from one layer to another, and by similar measurements we can determine the kinetics of diffusion between the lamellar layers. In the last study we measure the lamellar edges on a gradient thickness sample with optical microscopy. In so doing we can directly observe surface induced ordering, and for the first time, can precisely resolve the near surface ordering dynamics. / Thesis / Doctor of Philosophy (PhD)

Tensile strength modelling is usually done to predict the mechanical properties of lamellargraphite iron considering microstructural features. This work attempts to create a simplifiedmodel incorporating cooling rate and solidification time without considering themicrostructural features. This model will save time and cost in industry with the presence of acommercially available software such as Magmasoft which simulates solidification time andcooling rate. A plate model was designed for this purpose as the test geometry to createvariation in solidification time and cooling rate. By altering fraction solid, thermalconductivity, specific heat capacity in Magmasoft, a good fit was created between simulatedcooling curve and experimental cooling curves. The experimental UTS data of samples fromthree moulds were investigated and a regression model was created using statistics toolMinitab. The effect of solidification time and alloying on the graphite length Lmax was studiedfor twelve samples from each mould. Quantification of the effect of cooling rate and alloyingon the pearlitic properties of grey iron like matrix microhardness, pearlite inter-lamellarspacing was also investigated in this work.The developed model has sixty three percent correlation and explains UTS well in terms ofsolidification time and cooling rate. Microhardness measurements show that there is an almostlinear relationship between the cooling rate and microhardness of the matrix structure.Microhardness data also provides an overview of the pearlite fineness/interlamellar spacing.Analysis of the outliers showed that the presence of free ferrite on a fully pearlitic structurereduces the UTS significantly. Comparison of the regression model obtained from this workwith previous work showed that, there is a reduction in the predicted strength with this model.The effort to identify the reason for this reduction was not successful and needs furtherinvestigation. Pearlite inter-lamellar spacing measurement was not accurate. The relationshipbetween pearlite interlamellar spacing and matrix microhardness needs to be investigated inthe future using a better technique for pearlite spacing measurement. This will be useful tounderstand the effect of cooling rate on pearlite spacing and consequently on the UTS of greycast iron. / Draghållfasthetsmodellering görs vanligtvis för att förutsäga de mekaniska egenskaperna av lamellärt grafitjärn. Detta arbete har försökt att skapa en förenklad modell som innehåller kylhastighet och stelningstid utan att överväga mikrostrukturella egenskaper. Modellen kommer att spara tid och kostnad i industrin tillsammans med kommersiellt tillgänglig mjukvara som Magmasoft som simulerar stelningstiden och kylningshastighet. En plattformig modell utformades för detta ändamål som testgeometrin för att skapa variation i stelningstid och kylningshastighet. Genom att ändra fraktion fast fas, termisk konduktivitet och specifik värmekapacitet i Magmasoft skapades en bra anpassning mellan simulerade och experimentella kylkurvor. Experimentella draghållfasthetsdata (UTS) för prover från tre gjutningar undersöktes och en regressionsmodell skapades med hjälp av statistikverktyg Minitab. Effekten av stelningstid och legeringshalt på grafitlängden Lmax studerades för tolv prover från varje form. Effekten av kylhastighet och legering på de perlitiska egenskaperna hos grått järn som matrismikrohårdhet och perlitlamellavstånd undersöktes också i detta arbete.  Den utvecklade modellen har sextiotre procent korrelation och förklarar UTS väl med avseende på stelningstid och kylningshastighet. Mikrohårdhetsmätningar visar att det finns ett nästan linjärt förhållande mellan kylhastigheten och mikrohårdheten hos matrisstrukturen. Mikrohårdhetsdata ger också en översikt över perlitens finhet/interlamellära avstånd. Analys av outliers visade att närvaron av fri ferrit på en fullständigt perlitisk struktur minskar UTS betydligt. Jämförelse av regressionsmodellen erhållen från detta arbete med tidigare arbete visade det att det finns en minskning av den förutsagda styrkan med denna modell. Ansträngningen att identifiera orsaken till denna minskning var inte framgångsrik och behöver ytterligare undersökas. Perlit mellan lamellär avståndsmätning var inte korrekt. Förhållandet mellan perlitens interlamellära avstånd och matrismikrohet måste undersökas i framtiden med hjälp av en bättre teknik för perlit-avståndsmätning. Detta kommer att vara användbart att förstå effekten av kylhastighet på perlitavståndet och följaktligen på UTS av grå gjutjärn

Lamellar cast iron is a very important technical alloy and the most used material in the casting production, and especially in the automotive industry which is the major consumer. Beside the many great properties, it is inclined to form casting defects of which some can be prevented, and some may be repaired subsequently. Shrinkage porosity is a randomly returning problem, which is difficult to understand and to avoid. This defect is a volumetric deficiency which appear as cavities inside the casting in connection to the casting surface. Another frequent defect is the metal expansion penetration. This defect is a material surplus squeezed to the casting surface containing sand inclusion from the mold material. Shrinkage porosity is usually mentioned together with metal expansion penetration as the formation mechanism of both defects have common roots. It is also generally agreed, that these type of defects are related to the volumetric changes occurring during solidification. Additionally, the formation of these defects are in connection with the coherency of the primary austenite dendrites. The purpose of this work was to develop knowledge on factors affecting a volume-change related casting defect formation in order to minimize the presence of these defects in engine component production. This was done by extending the existing solidification investigation methods with novel solutions. Introduction of expansion force measurement in the determination of dendrite coherency combined with multi axial volume change measurement refine the interpretation of the solidification. Comparison of registered axial and radial linear deformation in cylindrical samples indicated an anisotropic volume change. Different methods for dendrite coherency determination have been compared. It was shown that the coherency develops over an interval. Dependent on the added inoculant the coherency is reached at different levels of fractions of a solidified primary phase. It is also shown, that inoculation has an effect on the nucleation and growth of the primary phase. Quantitative image analysis has been performed on the primary phase in special designed samples designed to provoke shrinkage porosity and metal expansion penetration. It was found, that the inter-dendritic space varies within a casting. This was explained by the coarsening of the primary dendrites which originates from differences in the local time of solidification. / <p>QC 20131210</p>