Orientador: Inés Joekes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-23T21:39:23Z (GMT). No. of bitstreams: 1 Pires-Oliveira_Rafael_M.pdf: 1845918 bytes, checksum: 804602d2e4268c29fa89904dda528728 (MD5) Previous issue date: 2013 / Resumo: Sabe-se que tensoativos (surfactantes) de xampus causam degradação da fibra capilar. Entretanto, não há na literatura estudos para quantificar os danos decorrentes do uso de tensoativos comerciais, que são impuros. Este trabalho avalia e compara a degradação de cabelo induzida pela ação de 16 tensoativos comerciais. Cabelo-padrão Caucasiano castanho escuro foi imerso em soluções aquosas de 16 tensoativos comerciais, de dodecil sulfato de sódio (SDS) e de água destilada, em condições que imitam às do banho (38 °C, agitação constante). Obtiveram-se os espectros UV¿Vis das soluções de lavagem. O método de Lowry foi utilizado para estimar a quantidade de proteínas extraída por SDS e por água destilada. As soluções de cabelo em todos os tensoativos e em água tornam-se coloridas após tempo prolongado (dias) de contato com os cabelos. A intensidade da cor varia de acordo com o caráter iônico do tensoativo e, somente no caso dos tensoativos, aumenta com o tempo de contato. Os espectros UV¿Vis obtidos mostram que o grau de degradação da fibra capilar varia de acordo com o índice HLB (detergência) dos tensoativos. Aniônicos extraem em maior quantidade (ou mais rapidamente) as substâncias do cabelo, anfotéricos degradam menos e não-iônicos degradam na mesma intensidade que a água. A degradação se dá pela extração proteínas, fragmentos de cutículas e grânulos de melanina, sem que haja alteração de cor do cabelo. Os espectros UV¿Vis das soluções de lavagem apresentam bandas em 275 nm (proteínas) e de 525 a 625 nm (melaninas). Estas bandas correlacionam-se com a estimativa de proteína pelo método de Lowry. A partir desta correlação, a degradação de cabelos devido ao uso de tensoativos pode ser quantificada e comparada pelos espectros UV¿Vis das soluções de lavagem com os tensoativos comerciais / Abstract: It is well known that shampoo's surfactant causes degradation of human hair. However, studies that quantify hair damage caused by commercial surfactants are lacking in scientific literature. This work investigates and compares hair damage induced by 16 commercial surfactants. Standard virgin dark-brown Caucasian hair was immersed in aqueous solutions of 16 commercial surfactants, sodium dodecyl sulfate (SDS), and distilled water under conditions that imitate bath (38 °C, constant shaking). UV¿Vis spectra were recorded of the washing solutions. Lowry method estimated the amount of protein extracted by SDS and distilled water. All surfactants solutions and water become colored after prolonged (days) contact with the hair. The color intensity varies with ionic character of the surfactant and, only in the case of surfactants, increases with contact time. UV¿Vis spectra show that the degree of hair damage varies according to the HLB index (detergency) of the surfactants. Anionics extract a greater amount (or faster) of hair substances, amphoterics extract fewer, and non-ionics degrade at the same intensity as water. The degradation is caused by the extraction of proteins, fragments of cuticle and melanin granules, without change hair color. UV¿Vis spectra of washing solutions show bands at 275 nm (proteins) and 525¿625 nm (melanins). These bands correlate with protein evaluation by the Lowry method. From this correlation, hair damage due to surfactants can be quantified and compared through UV¿Vis spectra of washing solutions of commercial surfactants / Mestrado / Físico-Química / Mestre em Química

Orientadores: Eneida de Paula, Cleyton Crepaldi Domingues / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T17:11:37Z (GMT). No. of bitstreams: 1 Casadei_BrunaRenata_M.pdf: 5692711 bytes, checksum: 9dcfea152b622eb3bd7d81b793794e3e (MD5) Previous issue date: 2011 / Resumo: A visão atual sobre membranas biológicas abarca descrições cada vez mais complexas devido, principalmente, à descoberta de novos papéis atribuídos aos lipídios e sua heterogeneidade. Em particular a associação de esfingolipídios e colesterol, acrescida de proteínas específicas, constitui a base da formação de domínios membranares conhecidos como lipid rafts. Rafts são microdomínios funcionais de biomembranas e estão envolvidos em diversos processos biológicos como reconhecimento celular, endocitose, transdução de sinal, entre outros processos. Uma estratégia experimental para estudar esses domínios é a preparação de frações de membrana parcialmente resistentes ao tratamento com detergentes, a baixa temperatura (4°C). Neste trabalho demonstramos pela primeira vez o preparo e caracterização de frações resistentes a detergente (DRMs) extraídas de membranas de eritrócito humano, a partir do tratamento com os detergentes não iônicos polioxietileno 20-oleil éter (Brij 98) e polioxietileno 20-cetil éter (Brij 58), seguida de separação por ultracentrifugação em gradiente de sacarose. Essas DRMs foram obtidas a 4°C e 37°C, a partir de membranas intactas e com conteúdo reduzido de colesterol (após tratamento com metil-beta-ciclodextrina) e foram comparadas com DRMs de Triton X-100 (TX-100) em relação ao tamanho, conteúdo proteico e lipídico e grau de organização da bicamada. As frações de DRM de Brij mostraram-se enriquecidas em colesterol e fosfolipídios com ácidos graxos de cadeia saturada (em especial ácido lignocérico das esfingomielinas), características consistentes com lipid rafts. No entanto, DRMs de TX-100 apresentaram maior proporção de esfingomielinas/glicerofosfolipídios que as frações obtidas com Brij, além de menor proporção de fosfatidiletanolamina, um lipídio preferencial da monocamada interna da membrana de eritrócitos. Em relação à solubilização proteica, a membrana do eritrócito foi mais resistente ao tratamento com Brij 98 do que aos outros dois detergentes. Flotilina-2 e estomatina foram encontradas nas frações de DRMs de Brij 98 e Brij 58, porém a redução do conteúdo de colesterol da membrana eritrocitária resultou numa menor associação da flotilina-2 àquelas DRMs. Resultados de Ressonância Paramagnética Eletrônica, com uso de marcadores de spin do tipo doxil-estearato não acusaram variação significativa no grau de empacotamento dos lipídios nas bicamadas de DRMs de Brij 98 e Brij 58 em relação à membrana eritrocitária, diferentemente do observado em DRMs de TX-100 e do que seria esperado para domínios lipídicos na fase líquido-ordenada. Em conclusão, DRMs de eritrócitos humanos, com características compatíveis aos domínios funcionais de biomembranas (rafts), foram obtidas tanto a 4ºC quanto a 37ºC; essas frações resistentes aos Brij apresentaram tamanho, composição proteica e lipídica e grau de empacotamento da bicamada diferente das DRMs de TX-100, indicando um processo de extração diferencial dos componentes da membrana eritrocitária induzida por esses detergentes / Abstract: Depiction of biological membranes has been turning more and more complex lately due to the new roles assigned to their lipid components and their heterogeneity. The association between sphingolipids and cholesterol is the basis of lipid rafts formation. Rafts are functional microdomains of biological membranes which have been associated to different biological processes such as cellular recognition, endocytosis and signal transduction, among others. An useful experimental approach to study lipid rafts is the preparation of membrane fractions partially resistant to detergents under low temperature (4ºC). In this work we report the isolation of detergent resistant membranes (DRMs) from human erythrocytes treated with the non-ionic detergents polioxyethylene 20-oleoyl ether (Brij 98) and polioxyethylene 20-cetyl ether (Brij 58) followed by sucrose gradient ultracentrifugation. Such DRMs were obtained at 4°C and 37°C, from cholesterol-depleted (treated with methyl-beta-cyclodextrin) and intact erythrocyte membranes and they compared to DRMs obtained with Triton X-100 (TX-100) regarding the size, protein and lipid content and membrane fluidity. Brij DRMs were found to be enriched in cholesterol and phospholipids containing saturated fatty acids (especially those from sphingomyelin), features commonly associated to lipid rafts. Nevertheless, TX-100 DRMs presented higher sphingomyelin/phospholipid ratios and lower phosphatidylethanolamine content (a glycerophospholipid mainly present in the inner leaflet) than the Brij's. As for protein solubilization, erythrocyte membranes were more resistant to Brij 98 than to the other two detergents. Flotillin-2 and stomatin were found in both Brij 98 and Brij 8 DRMs. However, flotillin-2 was partially solubilized when DRMs were prepared from cholesterol-depleted erythrocyte membrane. Electron paramagnetic resonance experiments, with doxyl stearic acid spin labels incorporated in the DRMs showed no significant changes in the bilayer compactness of Brij 98 and 58 DRMs in comparison to intact membrane, a unexpected result for lipid domains existing in a liquid-ordered phase, and in contrast to results previously observed with TX-100 DRMs. Altogether, these results show the isolation of DRMs from human erythrocytes treated with Brij 98 and Brij 58 at low (4°C) and physiological temperature (37°C). These detergent-resistant membrane fractions, obtained with Brij 98 and 58 presented some lipid rafts features, although with differences in protein and lipid contents, size and membrane fluidity in comparison to TX-100 DRMs. Besides, these results suggest that TX-100, Brij 98 and Brij 58 induced a different solubilization process on the erythrocyte membrane / Mestrado / Bioquimica / Mestre em Biologia Funcional e Molecular

Relationships between laundry practices, detergent knowledge, perception of water quality, and satisfaction with laundry results were determined in this study. The mail survey method was used to obtain information from Virginia Extension Homemakers in April 1986. Only respondents who did laundry in their own home or apartment were used. Two hundred and seventy-six respondents, from a sample of 370 homemakers, met the criterion. Spearman's rho correlation coefficient was used to determine if relationships existed between the variables. Low correlations were found between the variables; therefore, definite conclusions regarding relationships between the variables could not be made. Some discrepancies between actual and recommended laundry practices were found. Data also revealed a lack of knowledge regarding functions of detergent ingredients and proper use with specific water conditions, and some lack of awareness and misperceptions of water quality were detected. However, satisfaction with laundry results was generally good, and most homemakers seemed relatively pleased. The findings suggested that educational programs should emphasize information about detergent formulations and water characteristics. More information on recommended laundry practices and how they should be modified according to water conditions and detergent use also was needed. / M.S.

The use of cleaned-in-place milk pipe lines has been increasing for the past several years, particularly in conjunction with the farm bulk tank. It offers an opportunity for increasing operating efficiency by reducing the amount of labor needed for the milking operations. For many dairymen who have either outgrown or worn out existing facilities it is the least expensive and most efficient way of improving their milk handling facilities. The use of pressure in circulation cleaning of permanent milk pipe lines has been developed to give satisfactory results in the dairy plant. This method involves the use of considerable extra equipment which may be used for other purposes. Pipe line milker installations on most dairy farms are cleaned by the use of vacuum circulation rather than by pressure circulation cleaning. This enables the dairy farmer to utilize the same vacuum pump for circulation cleaning of the pipe line that is used for the milking operation. This eliminates the purchase of extra equipment that would be of no value except in the cleaning operation. Our present knowledge of the factors involved in the installation, the maintenance, and the care of cleaned-in-place milk pipe lines on the farm is limited. Dairymen who are now using such a system, and those considering its use, need more scientific information on the cleaning and sanitizing aspects of the farm milk pipe line installations. Cleaning compounds which have been designed for hand cleaning operations are commonly used for pipe line cleaning. It is impossible to obtain maximum cleaning efficiency of pipe lines with these compounds because they are milder in their alkaline action than compounds designed for in-place cleaning. The chemical activity of compounds designed for in-place cleaning is increased by the maintenance of a temperature of 140 °F. or higher. The circulation temperature range of 140 to 160 °F. as recommended by the several detergent manufacturers is difficult to maintain in actual practice. Many detergents recommended for circulation cleaning are not suitable for use in all types of farm-in-place installations due to the excessive foaming of the detergents in solution when placed under vacuum. This excessive foaming causes considerable difficulty in circulation operations and prevents proper solution contact with the pipe line surface. The problem of cleaning and sanitizing cleaned-in-place pipe lines on dairy farms is confounded by the absence of standardization in the engineering aspects of cleaned-in-place systems. The introduction of shortcuts or laxity in following the proper cleaning and sanitizing procedures may result in the lowering of milk quality. The primary objective of this investigation was to evaluate the cleaning and sanitizing ability of a number of cleaning compounds used in the vacuum circulation cleaning of a pipe line milker in a stanchion type dairy barn. A second objective was to evaluate the effect of circulation temperature ranges on the cleaning efficiency of the detergents. / Master of Science

Thesis (MBA)--Stellenbosch University, 2018. / ENGLISH ABSTRACT: Creating brand equity, that is, building a strong brand is a successful strategy for differentiating a product from competing brands (Aaker, 1991: 256). Brand equity provides sustainable competitive advantages, because it creates meaningful competitive barriers. Brand equity is developed through perceived quality, brand loyalty, brand awareness and brand associations, which cannot be either built or destroyed in the short run; but can be created only in the long run through carefully designed marketing investment. This study aims to examine the practicality and application of a customer-based brand equity model, based on Aaker’s (1991: 256) well-known conceptual framework of brand equity. The study investigates the causal relationships between the 4 dimensions of brand equity and brand equity itself. It specifically measured the way in which consumers’ perceptions of the dimensions of brand equity affected the overall brand equity evaluations. Data were collected from a sample of house-wives in South Africa. The study concludes that brand loyalty and perceived quality is the most influential dimension of brand equity. Support was also found for the brand awareness and brand association dimensions. Implications for marketing managers and marketing planners are discussed. / AFRIKAANSE OPSOMMING: Die skep van handelsmerkekwiteit “brand equity”, wat die bou van sterk handelsmerke impliseer, is 'n suksesvolle strategie om 'n produk van mededingende produkte te onderskei (Aaker, 1991: 256). Handelsmerkekwiteit voorsien volgehoue mededingende voordele omrede dit betekenisvolle mededingende hindernisse skep. Dit is ontwikkel op grond van kwaliteitsherkenning, handlesmerklojaliteit, kwaliteitsbewustheid en kwaliteitsassosiasies. Handelsmerkekwiteit kan geskep word deur omsigtige bemarkingsinvestering. Die doelwit van hierdie studie was om die toepaslikheid en praktiese toepassing van 'n kliëntgebasseerde ekwiteitsmodel te ondersoek en is gebaseer op Aaker (1991: 256) se bekende konseptuele handelsmerk-ekwiteitsraamwerk. Die studie ondersoek die kousale verwantskap tussen die vier handelsmerkekwiteitsdimensies en die algehele ekwiteitsevaluasie. Dit meet die wyse waarop die verbruiker se persepsie van die dimensies ekwiteit beïnvloed en die algehele ekwiteitsevaluasie. Data-insameling is gedoen onder huisvrouens in Suid-Afrika. Die resultate bevestig dat handelsmerklojaliteitlojaliteit en kwaliteitherkenning die mees invloedryke dimensies van handelsmerekwiteit is. Ondersteuning is ook gevind vir die kwaliteitsbewustheid en assosiasie dimensies. Hiervolgens is implikasies vir bemarkingbestuurders en -beplanners geformuleer.

Thesis (MBA)--Stellenbosch University, 2018. / ENGLISH ABSTRACT: Creating brand equity, that is, building a strong brand is a successful strategy for differentiating a product from competing brands (Aaker, 1991: 256). Brand equity provides sustainable competitive advantages, because it creates meaningful competitive barriers. Brand equity is developed through perceived quality, brand loyalty, brand awareness and brand associations, which cannot be either built or destroyed in the short run; but can be created only in the long run through carefully designed marketing investment. This study aims to examine the practicality and application of a customer-based brand equity model, based on Aaker’s (1991: 256) well-known conceptual framework of brand equity. The study investigates the causal relationships between the 4 dimensions of brand equity and brand equity itself. It specifically measured the way in which consumers’ perceptions of the dimensions of brand equity affected the overall brand equity evaluations. Data were collected from a sample of house-wives in South Africa. The study concludes that brand loyalty and perceived quality is the most influential dimension of brand equity. Support was also found for the brand awareness and brand association dimensions. Implications for marketing managers and marketing planners are discussed. / AFRIKAANSE OPSOMMING: Die skep van handelsmerkekwiteit “brand equity”, wat die bou van sterk handelsmerke impliseer, is 'n suksesvolle strategie om 'n produk van mededingende produkte te onderskei (Aaker, 1991: 256). Handelsmerkekwiteit voorsien volgehoue mededingende voordele omrede dit betekenisvolle mededingende hindernisse skep. Dit is ontwikkel op grond van kwaliteitsherkenning, handlesmerklojaliteit, kwaliteitsbewustheid en kwaliteitsassosiasies. Handelsmerkekwiteit kan geskep word deur omsigtige bemarkingsinvestering. Die doelwit van hierdie studie was om die toepaslikheid en praktiese toepassing van 'n kliëntgebasseerde ekwiteitsmodel te ondersoek en is gebaseer op Aaker (1991: 256) se bekende konseptuele handelsmerk-ekwiteitsraamwerk. Die studie ondersoek die kousale verwantskap tussen die vier handelsmerkekwiteitsdimensies en die algehele ekwiteitsevaluasie. Dit meet die wyse waarop die verbruiker se persepsie van die dimensies ekwiteit beïnvloed en die algehele ekwiteitsevaluasie. Data-insameling is gedoen onder huisvrouens in Suid-Afrika. Die resultate bevestig dat handelsmerklojaliteitlojaliteit en kwaliteitherkenning die mees invloedryke dimensies van handelsmerekwiteit is. Ondersteuning is ook gevind vir die kwaliteitsbewustheid en assosiasie dimensies. Hiervolgens is implikasies vir bemarkingbestuurders en -beplanners geformuleer.

A solubilização de solutos não iônicos através de um processo de partição entre água e a pseudo-fase micelar de tensoativos não iônicos foi estudada para álcoois secundários etoxilados com grau de etoxilação variando entre 7 e 40. Mostrou-se que o coeficiente de incorporação micelar, Ks, é independente do grau de etoxilação o que corrobora a hipótese de que a partição ocorre entre água e o núcleo hidrocarbônico da micela, que não é alterado pelo aumento do número de grupos de óxido de eteno na cabeça polar do tensoativo. O uso de relações lineares de energia livre, LSER, para a predição da capacidade de solubilização de álcoois secundários etoxilados forneceu, através de regressão múltipla linear a seguinte LSER como melhor modelo: log Ks = -0,42 + 1,21E - 1,73S -0,40A - 1,13B + 3,01V com R2 = 0,98 e valor de teste F de 1390. Nesta equação, V é o volume molar do soluto, A e B são a capacidade do soluto de atuar como doador e aceptor de pontes de hidrogênio, E é a refração molar em excesso e S representa a capacidade do soluto de interagir com o meio de solubilização através de interações do tipo dipolo-dipolo e dipolo-dipolo induzido. Mostrou-se que processos de limpeza aplicados à remoção de sujidades de tecidos e superfícies sólidas não estão correlacionados ao mecanismo de solubilização descrito por um processo de partição. A dependência da redução de tensão interfacial com o grau de etoxilação sugere que a eficiência de limpeza, para superfícies sólidas e para tecidos, está correlacionada de maneira direta, mas não linear, com a capacidade do tensoativo de concentrar-se na interface \"sujidade-solução aquosa de tensoativo\" reduzindo assim a tensão interfacial entre os dois meios. / The solubilization of non-ionic solutes via partitioning between water and the micellar pseudophase of non-ionic surfactants was evaluated for a series of secondary alcohol ethoxylates with hydrophile length varying from 7 to 40 ethylene oxide units. It was demonstrated that the micellar incorporation constant, Ks, is not dependent on the hydrophile length of the surfactant. The results obtained in this study support the hypothesis that the partitioning between water and the micellar core is not disturbed by the etheylene oxide hydrophilic groups. Linear solvation free energy relationships, LSER, were used to model the ability of the surfactants to solubilize non-ionic compounds. Multiple linear regression analysis provided the following LSER with R2 of 0.98 and F value of 1390: logK = -0,42 + 1,21E - 1,73S - 0,40A - 1,13B + 3,01V. In this LSER, V is a descriptor of solute molar volume, A and B capture the overall ability of the solute to act as a hydrogen bond donor and acceptor, E is the solute excess molar refraction and S is a descriptor of the ability of the solute to interact via dipole-dipole and dipole-induced dipole interactions with its surroundings. It was demonstrated that hard and soft surface cleaning efficiencies are not correlated with the solubilization process. It was shown, however, that the change in interfacial tension caused by the change in the hydrophile portion of the surfactants has a direct, but non-linear impact on the cleaing properties of aqueous solutions containing these surfactants.

A evolução dos níveis de utilização do fósforo pelo homem tem acarretado um aumento das taxas de exploração do nutriente, tornando iminente a escassez das reservas conhecidas e exploráveis, e contribuindo para deterioração da qualidade das águas. Atentos a essas questões, diversos países buscam reduzir os impactos das atividades humanas sobre as fontes de fósforo e diminuir os níveis de eutrofização dos corpos dágua através da aplicação de medidas direcionadas para a limitação ou banimento da utilização de tripolifosfato de sódio (STPP) nos detergentes, já que esta é considerada a principal fonte desse nutriente nos esgotos domésticos. De forma paralela, e com base nos resultados obtidos, são planejadas melhorias nos sistemas de tratamento de esgotos, considerando-se as peculiaridades econômicas, sociais e ambientais de cada região. Visando contribuir para uma melhor visualização do assunto, incorporando-o na realidade do Estado de São Paulo, o presente trabalho busca retratar a dinâmica do fósforo no meio ambiente a partir das atividades humanas desenvolvidas na bacia hidrográfica, utilizando o rio Tietê como estudo de caso. Os resultados obtidos indicam que o aporte desse nutriente nas águas está relacionado com a atividade urbana, principalmente de fontes domésticas, apontando para a necessidade de se aprimorar as formas de controle da quantidade de STPP utilizado na fabricação de detergentes e saponáceos. / The evolution of the levels of phosphorus usage by man has as consequence an increase of the nutrient exploitation levels, making imminent the shortage of the known and exploitable reserves, and contributing to deteriorate the quality of water. Mindful of these issues, many countries intend to reduce the impact of human activities on the phosphorus sources and to promote the reduction of eutrophication level of the water bodies by implement measures aiming to limit or banish the use of sodium tripolyphosphate (STPP) in detergents, for this is considered the main source of this nutrient in domestic sewage. At the same time, and based on the results obtained, improvements are planned on the sewage treatment systems, considering the economical, social and environmental particularities of each region. Aiming to contribute to a better understanding of this subject, and to make clearer in the reality of the State of Sao Paulo, this study intends to portrait the phosphorus dynamics in the environment from the human activities developed at hydrographic basins, using the Tietê River as a case study. The results obtained show that the level of this nutrient in the water is related to the urban activity, especially domestic sources, pointing out the need to perfection the ways to control the amount of STPP used when manufacturing detergents and soaps.

A evolução dos níveis de utilização do fósforo pelo homem tem acarretado um aumento das taxas de exploração do nutriente, tornando iminente a escassez das reservas conhecidas e exploráveis, e contribuindo para deterioração da qualidade das águas. Atentos a essas questões, diversos países buscam reduzir os impactos das atividades humanas sobre as fontes de fósforo e diminuir os níveis de eutrofização dos corpos dágua através da aplicação de medidas direcionadas para a limitação ou banimento da utilização de tripolifosfato de sódio (STPP) nos detergentes, já que esta é considerada a principal fonte desse nutriente nos esgotos domésticos. De forma paralela, e com base nos resultados obtidos, são planejadas melhorias nos sistemas de tratamento de esgotos, considerando-se as peculiaridades econômicas, sociais e ambientais de cada região. Visando contribuir para uma melhor visualização do assunto, incorporando-o na realidade do Estado de São Paulo, o presente trabalho busca retratar a dinâmica do fósforo no meio ambiente a partir das atividades humanas desenvolvidas na bacia hidrográfica, utilizando o rio Tietê como estudo de caso. Os resultados obtidos indicam que o aporte desse nutriente nas águas está relacionado com a atividade urbana, principalmente de fontes domésticas, apontando para a necessidade de se aprimorar as formas de controle da quantidade de STPP utilizado na fabricação de detergentes e saponáceos. / The evolution of the levels of phosphorus usage by man has as consequence an increase of the nutrient exploitation levels, making imminent the shortage of the known and exploitable reserves, and contributing to deteriorate the quality of water. Mindful of these issues, many countries intend to reduce the impact of human activities on the phosphorus sources and to promote the reduction of eutrophication level of the water bodies by implement measures aiming to limit or banish the use of sodium tripolyphosphate (STPP) in detergents, for this is considered the main source of this nutrient in domestic sewage. At the same time, and based on the results obtained, improvements are planned on the sewage treatment systems, considering the economical, social and environmental particularities of each region. Aiming to contribute to a better understanding of this subject, and to make clearer in the reality of the State of Sao Paulo, this study intends to portrait the phosphorus dynamics in the environment from the human activities developed at hydrographic basins, using the Tietê River as a case study. The results obtained show that the level of this nutrient in the water is related to the urban activity, especially domestic sources, pointing out the need to perfection the ways to control the amount of STPP used when manufacturing detergents and soaps.

The goal of this research is to study the neutralization of sulfuric acid by engine oils, and more specifically study how the presence of different oil additives affects the acid-neutralizing performance of engine oils by using capillary videomicroscopy. Nowadays the formulation of engine oils has been changing due to a trend of different regulations around the world that seek to diminish the emission of atmospheric pollution from all types of vehicles driven by internal combustion engines. In the particular case of large marine ships powered by low-speed two-stroke diesel engines, pollutant emissions are high given that the marine fuel they use can contain up to 4.5 wt. % of sulfur. But this sulfur content cap in marine fuel is bound to diminish dramatically during the ongoing decades due to regulations and therefore, the industry is coming up with new engine oil formulations accordingly as to comply with these changes. Here a technique called capillary videomicroscopy was used to study new changes to engine oil formulations. The reaction and dispersion of a sulfuric acid micro-droplet into formulations of marine cylinder lubricants (MCL) was studied by microscopically observing and measuring the shrinking of a micropipette-produced droplet in real time. It was found that MCL formulations having a base number (BN) of 40 had an acid-neutralizing performance comparable to those of having BN 70. On the other hand, the addition of fatty alcohols as final additives to MCL formulations so as to boost the MCL’s acid neutralization performance was found to be slightly effective although phase separation due to alcohol insolubility in MCL at room temperatures and other resilient phases formed upon reaction can be detrimental, hence the use of fatty alcohols for boosting any MCL formulation cannot be generalized and should be studied for each formulation. In the case of passenger car motor oils (PCMO), substitution of traditional oil additives by new sulfur-free additive species is driven by the need to prevent the catalytic converter's poisoning by eliminating any sulfur present in the exhaust gas. The effect of the polymeric dispersant on the acid neutralization performance was also studied. The formation of clear, thin and resilient shells surrounding sulfuric acid droplets upon reaction with some MCLs was noticed to be a detrimental aspect towards their acid neutralization performance and more importantly, due to the formation of potential precursors for cylinder liner engine deposits. Finally it is shown a modification of the capillary videomicroscopy technique that allowed long-term monitoring of the fate of microscopic particles while reacting or dissolving under flow, by suspending them using a balance between buoyancy and drag force from creep flow. / acase@tulane.edu