A corrosão é um processo eletroquímico espontâneo e, sabendo que diversos metais estão sujeitos a este fenômeno, a sua deterioração é inevitável, o que impõe à comunidade científica desafios para retardar tal efeito. A literatura sobre o tema aponta como uma das ações mais recorrentes para alcançar esse retardo a aplicação superficial de películas poliméricas, dentre as quais destaca-se o desenvolvimento de revestimentos inteligentes. A incorporação na tinta de formadores de filmes encapsulados confere ao revestimento a característica de autorreparação, e a escolha de silanos como agentes reticulantes se destaca positivamente, uma vez que o filme gerado pela molécula apresenta caráter hidrofóbico. Nesse contexto, o objetivo deste estudo é verificar, primeiro, a melhor condição de reticulação do silano na presença de radiação ultravioleta e, segundo, se a adição de microcápsulas de poli(ureia-formaldeído-melamina) contendo metacriloxissilano em uma tinta epóxi base solvente confere a este revestimento proteção contra a corrosão, pelo efeito de autorreparação. Para isso, estudou-se a cinética de polimerização do formador de filme e o seu encapsulamento em microcápsulas de poli(ureia-formaldeído-melamina). Determinada a melhor condição de encapsulamento, corpos de prova de aço carbono foram pintados com a tinta contendo as microcápsulas produzidas. O efeito de autorreparação - desencadeado pela ruptura das microcápsulas ao se provocar um defeito mecânico no revestimento - foi comprovado pelas técnicas de espectroscopia de impedância eletroquímica (EIE), técnica de varredura por eletrodo vibratório (SVET) e por ensaio acelerado de corrosão em câmara de névoa salina. / Corrosion is a spontaneous electrochemical process and, knowing that several metals are subjected to this phenomenon, its deterioration is inevitable, which imposes challenges for scientific community to delay this effect. The literature on this subject points out, as one of the most recurrent actions to achieve this delay, the superficial application of polymer films, which stands out the development of smart coatings with self-healing properties. The incorporation of encapsulated film formers gives to coatings the self-healing ability, and the choice of silanes as film-forming agent stands out positively since the film has a hydrophobic character. In this context, the aims of this study are, firstly, verify the best crosslinking condition of silane induced by UV light and, secondly, investigate whether the addition of poly(urea-formaldehyde-melamine) microcapsules containing methacryloxysilane into the solvent-based epoxy coating brings protection to this coating against corrosion by self-healing effect. For this purpose, the polymerization kinetics of the film former by ultraviolet radiation and their encapsulation in poly(urea-formaldehyde-melamine) microcapsules were studied. Given the best encapsulation condition, carbon steel panels were coated with the self-healing paint. The self-healing effect - triggered by the rupture of the microcapsules caused by an induced mechanical defect in the coating - was demonstrated by techniques as electrochemical impedance spectroscopy (EIS), scanning vibrating electrode technique (SVET) and by accelerated corrosion tests in salt spray chamber.

Realizou-se um estudo do processo descontínuo alimentado de fermentação, buscando encontrar as melhores condições de produção do ácido graxo gama-linolênico. Empregou-se como fonte de nitrogênio no meio de fermentação a uréia, que foi adicionada de forma exponencialmente crescente e como inóculo usou-se uma cepa de Spirulina platensis. Utilizou-se planejamento experimental e aplicou-se a metodologia de superfície de resposta, o qual permitiu a obtenção de equações que relacionaram as variáveis dependentes, como produtividade em células, conversão de nitrogênio em células, concentração máxima atingida de biomassa, porcentagem relativa de produção de ácido graxo gama-linolênico. com as variáveis independentes tempo de alimentação (Ta) e massa total de uréia adicionada (MUT). Os melhores resultados obtidos foram os seguintes: Px=117,26 mg/L.dia; Yx/n= 4,9; Xmax= 1759 mg/L e porcentagem de ácido graxo γ-linolênico na fração lipídica de 23,5 %, com 14 dias (Ta) e 1750 mg (MUT). / A Study on the fed-batch fermentation process was made seeking for the best Gamma-linolenic production condition. Mineral media was employed with urea as nitrogen source that was add with exponentially increasing feeding rates and Spirulina platensis as inoculum. Experimental design and a Response Surface Methodology were applied. It was composed by an experimental design which allowed a reduced number of the experiments and by the analysis of the results using equations which combined the interest variables dependent as: Productivity, best Gamma-linolenic production condition, Nitrogen convertion in Biomass, Highest Concentration and the study variables independent (Ta-feeding time and add urea-MUT). The best results were with (Ta-feeding time=14 days; add urea-MUT=1750 mg). In this conditions we had: Productivity=117,26 mg/L.day Best Gamma-linolenic production condition=23,5 per cent Nitrogen convertion in Biomass=4,9 Biggest Concentration.=1759 mg/L.

Foram realizados 2 experimentos no Departamento de Zootecnia da ESALQ/USP com o intuito de se avaliar o desempenho de tourinhos Nelore em confinamento. No experimento 1 foi avaliada a substituição da uréia (U) convencional por farelo de soja (FS) ou uréia de liberação lenta (ULL) (Optigen®) em rações de bovinos em terminação. Foram utilizados 100 tourinhos da raça Nelore (389 kg), distribuídos em 20 baias por 90 dias. As rações continham 8% de feno de Tifton (% da MS) e 65 a 69% de polpa cítrica no concentrado. Os 5 tratamentos experimentais foram assim designados (%MS): FS - ração com 5% de farelo de soja + 0,9% de uréia; U - ração com 1,7% de uréia; ULL 0,5 - ração com 0,5% de uréia de liberação lenta + 1,2% de uréia; ULL 1,0 - ração com 1,0% de uréia de liberação lenta + 0,8% de uréia; ULL1,5 - ração com 1,5% de uréia de liberação lenta + 0,3% de uréia. A ingestão de MS, o ganho de peso diário, a eficiência alimentar, o rendimento de carcaça, a espessura de gordura subcutânea e a área de olho de lombo não foram afetados pelas fontes de N testadas (P>0,05). Em conclusão, o desempenho de tourinhos Nelore em terminação alimentados com rações ricas em polpa cítrica, não é melhorado com a substituição da uréia convencional por farelo de soja ou uréia de liberação lenta na ração. No experimento 2 foram utilizados 192 animais (403 kg), distribuídos em 32 baias por 99 dias com objetivo de comparar rações contendo milho duro moído fino (M), laminado (L), ensilado (SGU) ou floculado (F), com 2 níveis de inclusão de bagaço de cana-deaçúcar: 12 ou 20% da MS da ração. Não houve interação entre processamentos do grão de milho e os níveis de forragem para nenhum parâmetro avaliado (P>0,05). A IMS foi maior (P<0,05) para o tratamento L comparado como os demais. O GPD foi maior (P<0,05) para os tratamentos F e SGU e a EA foi maior (P<0,05) para os tratamentos F, SGU e M comparados com L e para o tratamento F comparado com M. O rendimento de carcaça (RC) foi maior (P<0,05) para os tratamentos F e M. Os maiores valores (P<0,05) de energia líquida de manutenção e de ganho de peso das rações foram obtidos com os tratamentos F e SGU. A digestibilidade total do amido (DTA) foi maior nas rações contendo milho floculado, intermediária com milho moído fino e com milho ensilado e menor com milho laminado (P<0,05). A IMS foi menor (P<0,05) para os tratamentos contendo rações com 12% bagaço de cana-de-açúcar na MS da ração. O GPD, a EA, e o RC foram maiores nos animais dos tratamentos com 12% de bagaço de cana-de-açúcar na MS da ração (P<0,05). Os valores de energia líquida de manutenção e de ganho de peso das rações foram superiores (P<0,05) para os tratamentos com 12% de bagaço de cana-de-açúcar na MS. A DTA não foi alterada (P<0,05) em função do nível de inclusão do bagaço de cana-de-açúcar nas rações. Com base nos resultados conclui-se que o milho floculado e ensilado úmido são superiores, o milho moído é intermediário e o laminado inferior como fontes energéticas para tourinhos Nelore em terminação. Rações com 12% de bagaço de cana-de-açúcar contêm maior densidade energética e permitem melhor desempenho de tourinhos Nelore na fase de terminação comparadas com rações contendo 20% de bagaço de cana-de-açúcar. / Two trials were conducted at the Animal Sciences Department of the University of São Paulo Piracicaba-SP to evaluate the performance of finishing Nellore bulls. In trial 1 soybean meal (FS) and slow release urea (SRU) (Optigen®) replaced urea (U) on diets high in citrus pulp for finishing cattle. One hundred Nellore bulls (389 kg) were grouped in 20 pens for 90 days. Diets contained (%DM) 8% Tifton-85 grass hay and 92% concentrate (65 to 69% citrus pulp). The 5 treatment diets were isonitrogenous as follow (%DM): FS 5% soybean meal + 0.9% urea; U 1.7% urea; SRU 0.5 0.5% slow release urea + 1.2% urea; SRU 1.0 1.0% slow release urea + 0.8% urea; SRU 1.5 1.5% slow release urea + 0.3% urea. Animals were grouped in blocks according to initial BW. DMI, ADG, ADG/DMI, and carcass traits were not affected by N sources (P>0.05). In conclusion, on high citrus pulp diets, replacing soybean meal or slow release urea for urea does not improve performance of finishing Nelore bulls. In trial 2 192 finishing Nellore bulls (403 kg) grouped in 32 pens were fed for 99 days to compare diets containing fine ground, dry rolled, high moisture or steam flaked flint corn and two levels (12 or 20% on DM) of sugar cane bagasse. There was no interaction between corn processing methods and diet forage levels (P>0.05). DMI was higher (P<0.05) for dry rolled corn compared to the other 3 processing methods. ADG was higher (P<0.05) for steam flaked and high moisture corn than for ground or rolled corn. Feed efficiency (ADG/DMI) was higher (P<0.05) for steam flaked corn than for fine ground or dry rolled corn, and higher (P<0.05) for high moisture and ground corn than for dry rolled corn. Dressing was higher (P<0.05) for steam flaked and ground corn than for high moisture and dry rolled corn. The highest (P<0.05) diet energy values were observed for steam flaked and high moisture corn. Total tract starch digestibility was highest for steam flaked, intermediate for high moisture and ground corn and lowest for dry rolled corn (P<0.05). DMI was lower and ADG, feed efficiency, dressing and diet energy values were higher for cattle fed 12% than 20% forage diets (P<0.05). Forage level had no effect on diet starch digestibility (P>0.05). In conclusion, steam flaked and high moisture corn are highest, ground corn is intermediate and dry rolled corn is lowest in energy for finishing Nellore bulls. Performance of finishing Nellore bulls is improved with 12% sugar cane bagasse forage diets compared to 20% forage diets.

Nitrogen is one of the major elements essential for plant growth. It is the element most prone to depletion by cultivation and is usually found deficient in soils. In successful farming the problem of nitrogen supply is of special importance because plants need it in large amounts, it is fairly expensive to supply, and it is easily lost from the soil.

The United Nations Millennium Development Goals have prioritized improving access to sanitation, but unfortunately about a third of the global population is still without an improved sanitation source and one billion still practice open defecation. Lack of access to adequate and safe sanitation means the proliferation of dangerous pathogens in the environment, especially soil-transmitted helminths (STHs). In the Bocas del Toro Province of Panama (and similar locations in the world), composting latrines have been built in many of the indigenous communities in the area. They are a form of dry or ecological sanitation and are designed to produce an end product that can be used as a soil amendment for agricultural purposes. The issue is that many of these latrines are not working as designed and do not go through the composting process. Instead, they may act as incubators for harmful pathogens, such as Ascaris lumbricoides (roundworm). This research 1) provides an extensive literature review of the health situation of Panama, focusing on indigenous populations; soil-transmitted helminths and helminthiasis; Ascaris lumbricoides and its implications for wastewater reuse and land application of biosolids/sewage sludge; and inactivation of Ascaris in composting latrines; and 2) develops and proposes an experimental plan, with field-based methods, to assess the inactivation of Ascaris, by urea and solar heat (increased temperature), in composting latrines in Panama. Various experiments have been conducted in the laboratory using urea and increased temperature to inactive Ascaris; however few have been carried out in dry toilet technologies in the field. The contribution of this thesis is the field-based experimental design developed for inactivating Ascaris in composting latrines. The methods build upon previous research carried out both in the laboratory and in the field.

Graduation date: 1997

Ein viel diskutiertes Thema unserer Zeit ist die Zukunft der Energiegewinnung und Speicherung. Dabei nimmt die Nanowissenschaft eine bedeutende Rolle ein; sie führt zu einer Effizienzsteigerung bei der Speicherung und Gewinnung durch bereits bekannte Materialien und durch neue Materialien. In diesem Zusammenhang ist die Chemie Wegbereiter für Nanomaterialien. Allerdings führen bisher die meisten bekannten Synthesen von Nanopartikeln zu undefinierten Partikeln. Eine einfache, kostengünstige und sichere Synthese würde die Möglichkeit einer breiten Anwendung und Skalierbarkeit bieten. In dieser Arbeit soll daher die Darstellung der einfachen Synthese von Mangannitrid-, Aluminiumnitrid-, Lithiummangansilicat-, Zirkonium-oxinitrid- und Mangancarbonatnanopartikel betrachtet werden. Dabei werden die sogenannte Harnstoff-Glas-Route als eine Festphasensynthese und die Solvothermalsynthese als typische Flüssigphasensynthese eingesetzt. Beide Synthesewege führen zu definierten Partikelgrößen und interessanten Morphologien und ermöglichen eine Einflussnahme auf die Produkte. Im Falle der Synthese der Mangannitridnanopartikel mithilfe der Harnstoff-Glas-Route führt diese zu Nanopartikeln mit Kern-Hülle-Struktur, deren Einsatz als Konversionsmaterial erstmalig vorgestellt wird. Mit dem Ziel einer leichteren Anwendung von Nanopartikeln wird eine einfache Beschichtung von Oberflächen mit Nanopartikeln mithilfe der Rotationsbeschichtung beschrieben. Es entstand ein Gemisch aus MnN0,43/MnO-Nanopartikeln, eingebettet in einem Kohlenstofffilm, dessen Untersuchung als Konversionsmaterial hohe spezifische Kapazitäten (811 mAh/g) zeigt, die die von dem konventionellen Anodenmaterial Graphit (372 mAh/g) übersteigt. Neben der Synthese des Anodenmaterials wurde ebenfalls die des Kathodenmaterials Li2MnSiO4-Nanopartikeln mithilfe der Harnstoff-Glas-Route vorgestellt. Mithilfe der Synthese von Zirkoniumoxinitridnanopartikeln Zr2ON2 kann eine einfache Einflussnahme auf das gewünschte Produkt durch die Variation derReaktionsbedingungen, wie Harnstoffmenge oder Reaktionstemperatur, bei der Harnstoff-Glas-Route demonstriert werden. Der Zusatz von kleinsten Mengen an Ammoniumchlorid vermeidet, dass sich Kohlenstoff im Endprodukt bildet und führt so zu gelben Zr2ON2-Nanopartikeln mit einer Größe d = 8 nm, die Halbleitereigen-schaften besitzen. Die Synthese von Aluminiumnitridnanopartikeln führt zu kristallinen Nanopartikeln, die in eine amorphe Matrix eingebettet sind. Die Solvothermalsynthese von Mangancarbonatnanopartikel lässt neue Morphologien in Form von Nanostäbchen entstehen, die zu schuppenartigen sphärischen Überstrukturen agglomeriert sind. / The development of new methods toward alternative clean energy production and efficient energy storage is a hot topic nowadays. In this context nanoscience has an important role to find suitable ways of increasing the efficiency of storage and production of energy of already known materials and new materials. However, until now the most well-known syntheses of MnN0,43 and Zr2ON2 nanoparticles lead to undefined particles. A simple, cheap and safe synthesis would offer the possibility of broader applications and scalability. We herein present the so-called urea-glass route which is used as a sol-gel process. This synthetic route leads to well-defined particle sizes, novel particle morphologies and allows the tailoring of the desired products. In the case of the synthesis of manganese nitride nanoparticles (MnN0,43), nanoparticles with a core-shell structure are obtained, their use as conversion materials in batteries is first introduced. On the other hand, the formation of zirconium oxynitride nanoparticles (Zr2ON2) can be easily influenced by varying the reaction conditions such as the amount of urea or the reaction temperature. The addition of small amounts of salt prevents the formation of carbon in the final product, leading to yellow Zr2ON2 nanoparticles with a size of d = 8 nm which show semiconductor behavior.

Moisturizers are used in various types of dry skin disorders, but also by people with healthy skin. It is not unusual that use of moisturizers is continued for weeks, months, or even years. A number of moisturizers have been shown to improve the skin barrier function, while others to deteriorate it, but the reason for observed effects remains unknown. Further understanding of the mechanism by which long-term treatment with moisturizers influences the skin barrier would have clinical implications, as barrier-deteriorating creams may enhance penetration of allergens or irritants and predispose to dry skin and eczema, while barrier-improving ones could reduce many problems. The present research combined non-invasive techniques with analyses of skin biopsies, allowing studies of the epidermis at molecular and cellular level. Test moisturizers were examined on healthy human volunteers for their effect on the skin barrier, with regard to such factors as pH, lipid type, and presence of a humectant, as well as complexity of the product. After a 7-week treatment with the moisturizers, changes in transepidermal water loss, skin capacitance, and susceptibility to an irritant indicated a modified skin barrier function. Moreover, the mRNA expression of several genes involved in the assembly, differentiation and desquamation of the stratum corneum, as well as lipid metabolism, was altered in the skin treated with one of the moisturizers, while the other moisturizer induced fewer changes. In conclusion, long-term use of moisturizers may strengthen the barrier function of the skin, but also deteriorate it and induce skin dryness. Moisturizers have also a significant impact on the skin biochemistry, detectable at molecular level. Since the type of influence is determined by the composition of a moisturizer, more careful selection of ingredients could help to design moisturizers generating a desired clinical effect, and to avoid ingredients with a negative impact on the skin.

Lanthanum orthoborate (LaBO3) has aroused interest of scientists for many decades because of their remarkable properties and potential applications. They provide favorable magnetic properties for various applications. Additionally, they possess high VUV transparency and exceptional optical damage when they compose with rare earth elements. This study comprises the synthesis of pure lanthanum orthoborate, europium, dysprosium and terbium doped lanthanum orthoborate by two methods with v three fuels, citric acid, glycine and urea. LaBO3 has already been synthesized by various methods, however / in this work, two alternative roads are suggested, microwave assisted method and sol-gel microwave assisted method. The second task of the work is to find out the best luminescent product by altering the synthesis conditions, type of the doping material and the doping amount of the rare earth element. For the microwave assisted combustion method, urea was used as a fuel. After synthesis in the microwave oven, further heating up to 950&deg / C was performed. For the microwave assisted sol-gel method, citric acid and glycine were used. After obtaining the gel mixture, the product is synthesized in the microwave oven at 1200 W for ten minutes. For this route, again 950&deg / C heating for 2 hours was performed. Powder X-ray diffraction method was employed for the characterization of the material. The morphological properties of doped and un-doped materials were studied by SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope). Besides, FT-IR (Fourier Transform Infra red) spectrometry analyses were performed to detect the differences in the bond structure and also to identify the corresponding bands. Luminescence studies were performed to detect the best emission intensities by using Fluorescence spectroscopy. The XRD patterns confirmed that lanthanum orthoborate production was successful by three precursors. The space group is Pnma, and the crystal system is orthorhombic with the unit cell dimensions / a= 5.8761(1)

Access to sustainable sanitation systems is a determining factor in human health and economic development. However, more than a third of the world’s population lives without access to improved sanitation facilities. To meet the sanitation United Nations Millennium Development target, "halve, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation", a wide range of non conventional sanitation technologies have been implemented in developing countries, including waterless systems. These systems function by diverting urine away from feces and collecting, storing, and dehydrating the fecal material in watertight dehydration vaults. From a public health perspective, adequate inactivation of fecal pathogens in a sanitation system is essential before any use or disposal of fecal material. In rural areas of El Salvador, the solar toilet is capable of inactivating fecal pathogens and reducing the prevalence of parasitic infections in its users when compared to other waterless systems. Nevertheless, not all solar toilets are able to inactivate completely Ascaris spp. ova after the recommended storage period. Un-ionized ammonia (NH3) has the potential to inactivate pathogens in solutions and sludge, including Ascaris spp. ova. This study hypothesized that adding ammonia to the solar toilet will improve the technology since pathogen inactivation with ammonia could be potentiated by the alkaline medium and high temperatures achieved inside the toilet vaults. To evaluate this approach, a series of experiments in solution and biosolid were performed in a laboratory environment using physical and chemical parameters similar to those achieved by the solar toilet. Eggs of the swine Ascaris species, Ascaris suum, were used as model in all experiments. In ammonia solution, the parasite ova were stored for a period of three days and; in biosolid, the parasite ova were stored for two months. Urea was used as the source of ammonia in biosolid. In addition to the experiments with ammonia, normal viability and morphological changes within the parasite ova during incubation in vitro at 28 C° were investigated and described to complement current literature published. Results from the experiments in ammonia solution indicated that addition of ammonia (1% and 2%) could improve the system since the critical parameters that significantly reduced A. suum ova viability to zero in three days could be achieved by the solar toilet: temperature of 35°C or higher and pH value of 9.3. Results from the experiments in biosolid further showed that inactivation of A. suum ova was faster in samples exposed to urea and to temperatures higher than 28°C. All samples exposed to urea achieved 100% inactivation after 14 days (28°C), 3 days (35°C) and 24 hours (40°C and 45°C). Survival analysis of the data showed that there was a significant difference (p value <.0001) between the inactivation achieved in the samples exposed to urea (1% and 2%) and the samples not exposed to urea. A logistic regression analysis estimated the effect of Urea (Treatment, OR: 25.9), Temperature (OR: 1.8), and Storage (OR: 1.17) on inactivation. Results from the experiment with A. suum ova in normal incubation solution showed that the ova went through clearly identified morphological changes at different speed of development. Two new additional stages of development were identified (Pre-larva 1 and Pre-larva 2) and no significant statistical difference was observed among the viability reported early in incubation and the one reported after three weeks of in vitro incubation, indicating that early stages of development may be use as an alternative to reduce the time to report viability. The results of this study suggest that inactivation of Ascaris spp ova by ammonia is possible in fecal material stored in the solar toilet or any other dry toilet, if the following physical and chemical conditions are met: a closed vault with a minimum temperature of 28°C; an initial pH of 8.3, minimum moisture of 27.5%, and addition of 1% urea to the biosolid. At 28°C longer storage time would be required for 100% inactivation while at higher temperatures less time of storage would be necessary. A community intervention is recommended to include field conditions and human behavior as other predictors for Ascaris spp. inactivation by ammonia.