Africa is uniquely vulnerable to the occurrence of drought. A rise in temperatures over Southern Africa occurs at almost twice that of the global rate. South Africa has begun to experience an increase in the frequency of drought, particularly in the Western and Eastern Cape. Droughts are associated with several health effects. The direct and indirect risks of climate change to human health have become a global concern. The most recent systematic review available on the adverse health effects associated with drought was published in 2013, and as such, an up-to-date review focusing on Africa is needed to inform a Cape Town specific health vulnerability index. This study aims to provide a review of available research exploring the association between drought and adverse health effects in Africa. The rationale for this study is to provide a solid research foundation from which a drought-specific health vulnerability index for Cape Town can be developed. A narrative review of original studies and published reviews was conducted. An extensive electronic literature search was performed using a combination of keywords, Medical Subject Heading (MeSH) terms and free text words. The Critical Appraisal Toolkit (CAT) was used to assess the quality of included studies. A total of 1922 publications were identified, of which twenty-four articles were included in this review. The main drought-related health effects that emerged were divided into 4 main categories: (1) drought and nutritional health including malnutrition, poor childhood health outcomes (wasting, stunting and underweight), mortality, anaemia, and nutritionrelated disability; (2) drought and food consumption including micronutrient deficiencies and motor neuron diseases; (3) drought and water-borne, water-washed and water- related diseases including cholera outbreaks, diarrhoeal diseases, protozoa parasite transmission, scabies outbreaks, trachoma, vector-borne disease outbreaks and malaria-related mortality; and (4) drought and health behaviours including health perceptions and health-seeking behaviours, HIV prevention and care behaviours and family planning practices. There was generally limited evidence in all health categories with several limitations. These limitations include studies with methodological weaknesses (e.g. a lack of comparison to a non-drought period), the singularity of published studies on health effects associated with drought and studies which did not account for potential confounders. While the evidence from the included studies is limited, this study highlights gaps in literature to encourage further research into understanding the direct and indirect impacts of drought on health, particularly in vulnerable groups. Furthermore, the results of this study emphasized the contextual factors which lower an individual's adaptive capacity and identified key indicators that can be used to begin to develop a broad framework for a vulnerability index

A research program was developed to investigate basic and applied aspects of toxicity, both lethal and sublethal, of hemoxidants, particularly nitrite, on fish, non-fish aquatic vertebrates, and crayfish. The major objectives of this research were to determine A) acute and sublethal toxicity of nitrite to selected aquatic organisms: 1. aquatic salamander larvae, Ambystoma texanum, 2. swamp crayfish, Procambarus simulans, 3. bluegill, Lepomis macrochirus, 4. bullfrog, tadpoles, Rana catesbiana, 5. channel catfish, Ictalurus punctatus, B) the influence of environmental chloride on acute and sublethal exposures to hemoxidants: 1. on acute nitrite toxicity to salamander larvae, crayfish, and bluegill, 2. on nitrite-induced methemoglobinemia in bullfrog tadpoles, Rana catesbian, C) the effect of environmental hydrogen ion concentrations (pH) on acute nitrite toxicity 1. to the crayfish, Procambarus simulans, 2. to the bluegill, Lepomis macrochirus, D) the effect of temperature in sublethal exposures to nitrite 1. methemoglobin formation in channel catfish exposed at different acclimation temperatures, 2. recovery from methemoglobinemia at different acclimation temperatures, E) the effect of the fish anesthetic TMS-222 on nitrite-induced methemoglobinemia in channel catfish 1. supression of nitrite-induced methemoglobinemia, 2. dose-response curve for TMS-222 induced methemoglobinemia, and F) if a methemoglobin reductase system is present in channel catfish.

Os sedimentos aquáticos podem fornecer importantes subsídios na avaliação dos ecossistemas aquáticos lênticos, uma vez que grande parte dos nutrientes se encontra no estado sólido. A ocorrência de uma floração de cianobactérias tóxicas originada no Blang, segundo de três reservatórios em cascata do Sistema Salto de Hidrelétricas, localizado no município de São Francisco de Paula (RS), motivou a investigação das possíveis fontes de nutrientes, especialmente de fósforo (P) que foi identificado como limitante para a eutrofização. Foram investigadas fontes de origens difusas (solos, águas e sedimentos dos tributários) e pontuais (uso urbano e a carga interna representada pelo sedimento do leito dos reservatórios). Os resultados mostraram características oligotróficas nas fontes externas e a presença de P disponível em excesso no sedimento do leito, indicando que a carga interna poderia ser uma fonte significativa de nutrientes. A possibilidade de circulação da água hipolimnética foi investigada através de números adimensionais e características físicas do corpo de água, demonstrando que dificilmente ocorreria, uma vez que somente eventos climáticos extremos poderiam provocar a inversão da massa líquida. Excluídas as fontes externas, os resultados sugerem que a fertilização do reservatório Blang tenha sido causada pela abertura da comporta de fundo do reservatório Divisa, localizado imediatamente à montante, durante uma estiagem. O segundo objetivo desta pesquisa foi avaliar a importância dos agregados de partículas e da seleção granulométrica para a análise química de nutrientes em sedimentos aquáticos. Resultados obtidos em sedimentos de ambientes lóticos e lênticos (Sistema Salto, RS), demonstraram que os agregados maiores (465 - 63 μm) concentram nitrogênio nos ambientes lênticos, por isso a análise deve ser realizada, preferencialmente, na fração ≤ 465 μm em sedimentos de ambientes lênticos e na fração ≤ 63 μm dos ambientes lóticos. O último objetivo deste estudo foi testar os efeitos da oxidação sobre a capacidade e a velocidade da sorção de fosfato em sedimentos aquáticos orgânicos, identificando as melhores condições para retenção. Foram utilizados sedimentos aquáticos siliciclásticos de origens distintas, principalmente no que se refere ao clima e à origem do conteúdo orgânico, alóctone e autóctone, representados pelos tipos Dy (Reservatório Divisa, RS) e Sapropel (Reservatório de Tapacurá, São Lourenço da Mata, PE) respectivamente. O experimento foi realizado em suspensões de sedimentos mantidos sob níveis de potencial redox compreendidos entre - 200 mV e + 400 mV. Resultados demonstram que a sorção de fosfato é maior no sedimento tipo Dy em condições reduzidas e no Sapropel em condições oxidadas. / Water-borne sediments can provide important information for evaluating lentic aquatic ecosystems because a large proportion of their nutrients are found in the solid phase. A toxic algal bloom in the Blang Reservoir, the second of three in the Salto System chain of hydroelectric dams located in Sao Francisco de Paula in Rio Grande do Sul, Brazil, motivated the investigation of possible nutrient sources, especially phosphorus, which was identified as the limiting nutrient for eutrophization. Non-point sources, including soil, water and sediment carried by tributaries, and point sources, including urban areas and the internal load from the reservoir bottom, were examined. Results showed oligotrophic characteristics in the external sources and excess P availability in bottom sediments, indicating that the internal load may be a significant source of nutrients. The possible circulation of hypolimnic water was investigated using adimensional numbers and physical characteristics of the body of water, demonstrating that this is unlikely to occur, since only extreme climatic events could cause inversion of the liquid mass. By excluding external sources, results suggest that the fertilization of the Blang Reservoir was most likely caused by the opening of the floodgates from the Divisa Reservoir immediately upstream during a drought period. The second goal of this study was to evaluate the importance of particle aggregates and particle size selection for chemical analyses of nutrients and water-borne sediments. Results from sediments in lentic and lotic environments from the Salto System show that the larger aggregates (465 - 63 μm) concentrate nitrogen under lentic conditions and that, therefore, analyses should be performed on the fraction smaller than 465 μm in lentic environments and in the fraction ≤ 63 μm in lotic environments. The final objective of this study was to test the effects of oxidation on the phosphate sorption capacity and rate in organic aquatic sediments, identifying the best conditions for retention. Silicate aquatic sediments from different origins in terms of climate and source of organic content (allochtonous or autochtonous) were used, and were represented by the types Dy (Divisa Reservoir, RS) and Sapropel (Tapacurá Reservoir, São Lourenço da Mata, PE), respectively. The experiment was carried out in suspended sediment maintained under levels of redox potential between –200mV and +400mV. Results demonstrated that phosphate sorption is greatest in sediment type Dy under reduced conditions and in Sapropel under oxidized conditions.

Os sedimentos aquáticos podem fornecer importantes subsídios na avaliação dos ecossistemas aquáticos lênticos, uma vez que grande parte dos nutrientes se encontra no estado sólido. A ocorrência de uma floração de cianobactérias tóxicas originada no Blang, segundo de três reservatórios em cascata do Sistema Salto de Hidrelétricas, localizado no município de São Francisco de Paula (RS), motivou a investigação das possíveis fontes de nutrientes, especialmente de fósforo (P) que foi identificado como limitante para a eutrofização. Foram investigadas fontes de origens difusas (solos, águas e sedimentos dos tributários) e pontuais (uso urbano e a carga interna representada pelo sedimento do leito dos reservatórios). Os resultados mostraram características oligotróficas nas fontes externas e a presença de P disponível em excesso no sedimento do leito, indicando que a carga interna poderia ser uma fonte significativa de nutrientes. A possibilidade de circulação da água hipolimnética foi investigada através de números adimensionais e características físicas do corpo de água, demonstrando que dificilmente ocorreria, uma vez que somente eventos climáticos extremos poderiam provocar a inversão da massa líquida. Excluídas as fontes externas, os resultados sugerem que a fertilização do reservatório Blang tenha sido causada pela abertura da comporta de fundo do reservatório Divisa, localizado imediatamente à montante, durante uma estiagem. O segundo objetivo desta pesquisa foi avaliar a importância dos agregados de partículas e da seleção granulométrica para a análise química de nutrientes em sedimentos aquáticos. Resultados obtidos em sedimentos de ambientes lóticos e lênticos (Sistema Salto, RS), demonstraram que os agregados maiores (465 - 63 μm) concentram nitrogênio nos ambientes lênticos, por isso a análise deve ser realizada, preferencialmente, na fração ≤ 465 μm em sedimentos de ambientes lênticos e na fração ≤ 63 μm dos ambientes lóticos. O último objetivo deste estudo foi testar os efeitos da oxidação sobre a capacidade e a velocidade da sorção de fosfato em sedimentos aquáticos orgânicos, identificando as melhores condições para retenção. Foram utilizados sedimentos aquáticos siliciclásticos de origens distintas, principalmente no que se refere ao clima e à origem do conteúdo orgânico, alóctone e autóctone, representados pelos tipos Dy (Reservatório Divisa, RS) e Sapropel (Reservatório de Tapacurá, São Lourenço da Mata, PE) respectivamente. O experimento foi realizado em suspensões de sedimentos mantidos sob níveis de potencial redox compreendidos entre - 200 mV e + 400 mV. Resultados demonstram que a sorção de fosfato é maior no sedimento tipo Dy em condições reduzidas e no Sapropel em condições oxidadas. / Water-borne sediments can provide important information for evaluating lentic aquatic ecosystems because a large proportion of their nutrients are found in the solid phase. A toxic algal bloom in the Blang Reservoir, the second of three in the Salto System chain of hydroelectric dams located in Sao Francisco de Paula in Rio Grande do Sul, Brazil, motivated the investigation of possible nutrient sources, especially phosphorus, which was identified as the limiting nutrient for eutrophization. Non-point sources, including soil, water and sediment carried by tributaries, and point sources, including urban areas and the internal load from the reservoir bottom, were examined. Results showed oligotrophic characteristics in the external sources and excess P availability in bottom sediments, indicating that the internal load may be a significant source of nutrients. The possible circulation of hypolimnic water was investigated using adimensional numbers and physical characteristics of the body of water, demonstrating that this is unlikely to occur, since only extreme climatic events could cause inversion of the liquid mass. By excluding external sources, results suggest that the fertilization of the Blang Reservoir was most likely caused by the opening of the floodgates from the Divisa Reservoir immediately upstream during a drought period. The second goal of this study was to evaluate the importance of particle aggregates and particle size selection for chemical analyses of nutrients and water-borne sediments. Results from sediments in lentic and lotic environments from the Salto System show that the larger aggregates (465 - 63 μm) concentrate nitrogen under lentic conditions and that, therefore, analyses should be performed on the fraction smaller than 465 μm in lentic environments and in the fraction ≤ 63 μm in lotic environments. The final objective of this study was to test the effects of oxidation on the phosphate sorption capacity and rate in organic aquatic sediments, identifying the best conditions for retention. Silicate aquatic sediments from different origins in terms of climate and source of organic content (allochtonous or autochtonous) were used, and were represented by the types Dy (Divisa Reservoir, RS) and Sapropel (Tapacurá Reservoir, São Lourenço da Mata, PE), respectively. The experiment was carried out in suspended sediment maintained under levels of redox potential between –200mV and +400mV. Results demonstrated that phosphate sorption is greatest in sediment type Dy under reduced conditions and in Sapropel under oxidized conditions.

Made available in DSpace on 2014-06-11T19:27:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-05-10Bitstream added on 2014-06-13T19:36:07Z : No. of bitstreams: 1 arcoverdefilho_dm_me_rcla.pdf: 6204134 bytes, checksum: 02ac879ad43e1d76e4f0e87c4a264bd8 (MD5) / A forma pela qual os recursos hídricos são utilizados vem degradando os mananciais a um nível tal que se compromete a qualidade de vida das populações. Exauridos pela atividade antrópica, esse fato pode se tornar, no futuro, causador de conflitos. O setor de saneamento básico, sendo um dos que mais se utilizam dos recursos hídricos, é parte de fundamental importância no sentido de promover a melhoria da qualidade de vida da população, utilizando os recursos hídricos de maneira ambientalmente sustentável e garantindo os serviços de abastecimento de água e esgotamento sanitário, mesmo no cenário atual de crescente urbanização, quando se enfrenta a falta de recursos suficientes para expansão dos serviços e a ineficiência no uso dos recursos arrecadados no setor. No quadro dessa problemática, este estudo analisa o espaço urbano da zona leste de Teresina, focalizando o saneamento básico em seus bairros no que diz respeito à problemática dos serviços de abastecimento de água, esgoto sanitário e coleta de lixo. Verifica-se que as camadas mais pobres da população são as que mais sofrem as conseqüências da falta de infraestrutura desses serviços, com a ocorrência de doenças como hepatite e enteroinfecções, contribuindo para a redução da qualidade de vida da população e evidenciando ainda a segregação social existente entre os bairros de uma mesma região da cidade / The way in which water resources are used is degrading the water sources at a level that compromises the quality of life of populations. Depleted by human activity, this may become in the future, causing conflicts. The basic sanitation sector, being one of the most use of water resources, is part of fundamental importance to improving the quality of life of the population using water resources in an environmentally sustainable manner and ensuring the supply services water and sanitation, even in the current scenario of increasing urbanization, when faced with the lack of sufficient resources for expansion of services and inefficiency in the use of funds raised in the industry. As part of this problem, this study examines the urban spaces of the east side of Teresina, focusing on sanitation in their neighborhoods with respect to the issue of services of water supply, sewage and garbage collection. It appears that the poorest of the population are the ones that suffer the consequences of lack of infrastructure such services, with the occurrence of diseases like hepatitis and enteroinfecções, contributing to reduced quality of life of people and showing also the social segregation between the neighborhoods of the same region of the city

Os sedimentos aquáticos podem fornecer importantes subsídios na avaliação dos ecossistemas aquáticos lênticos, uma vez que grande parte dos nutrientes se encontra no estado sólido. A ocorrência de uma floração de cianobactérias tóxicas originada no Blang, segundo de três reservatórios em cascata do Sistema Salto de Hidrelétricas, localizado no município de São Francisco de Paula (RS), motivou a investigação das possíveis fontes de nutrientes, especialmente de fósforo (P) que foi identificado como limitante para a eutrofização. Foram investigadas fontes de origens difusas (solos, águas e sedimentos dos tributários) e pontuais (uso urbano e a carga interna representada pelo sedimento do leito dos reservatórios). Os resultados mostraram características oligotróficas nas fontes externas e a presença de P disponível em excesso no sedimento do leito, indicando que a carga interna poderia ser uma fonte significativa de nutrientes. A possibilidade de circulação da água hipolimnética foi investigada através de números adimensionais e características físicas do corpo de água, demonstrando que dificilmente ocorreria, uma vez que somente eventos climáticos extremos poderiam provocar a inversão da massa líquida. Excluídas as fontes externas, os resultados sugerem que a fertilização do reservatório Blang tenha sido causada pela abertura da comporta de fundo do reservatório Divisa, localizado imediatamente à montante, durante uma estiagem. O segundo objetivo desta pesquisa foi avaliar a importância dos agregados de partículas e da seleção granulométrica para a análise química de nutrientes em sedimentos aquáticos. Resultados obtidos em sedimentos de ambientes lóticos e lênticos (Sistema Salto, RS), demonstraram que os agregados maiores (465 - 63 μm) concentram nitrogênio nos ambientes lênticos, por isso a análise deve ser realizada, preferencialmente, na fração ≤ 465 μm em sedimentos de ambientes lênticos e na fração ≤ 63 μm dos ambientes lóticos. O último objetivo deste estudo foi testar os efeitos da oxidação sobre a capacidade e a velocidade da sorção de fosfato em sedimentos aquáticos orgânicos, identificando as melhores condições para retenção. Foram utilizados sedimentos aquáticos siliciclásticos de origens distintas, principalmente no que se refere ao clima e à origem do conteúdo orgânico, alóctone e autóctone, representados pelos tipos Dy (Reservatório Divisa, RS) e Sapropel (Reservatório de Tapacurá, São Lourenço da Mata, PE) respectivamente. O experimento foi realizado em suspensões de sedimentos mantidos sob níveis de potencial redox compreendidos entre - 200 mV e + 400 mV. Resultados demonstram que a sorção de fosfato é maior no sedimento tipo Dy em condições reduzidas e no Sapropel em condições oxidadas. / Water-borne sediments can provide important information for evaluating lentic aquatic ecosystems because a large proportion of their nutrients are found in the solid phase. A toxic algal bloom in the Blang Reservoir, the second of three in the Salto System chain of hydroelectric dams located in Sao Francisco de Paula in Rio Grande do Sul, Brazil, motivated the investigation of possible nutrient sources, especially phosphorus, which was identified as the limiting nutrient for eutrophization. Non-point sources, including soil, water and sediment carried by tributaries, and point sources, including urban areas and the internal load from the reservoir bottom, were examined. Results showed oligotrophic characteristics in the external sources and excess P availability in bottom sediments, indicating that the internal load may be a significant source of nutrients. The possible circulation of hypolimnic water was investigated using adimensional numbers and physical characteristics of the body of water, demonstrating that this is unlikely to occur, since only extreme climatic events could cause inversion of the liquid mass. By excluding external sources, results suggest that the fertilization of the Blang Reservoir was most likely caused by the opening of the floodgates from the Divisa Reservoir immediately upstream during a drought period. The second goal of this study was to evaluate the importance of particle aggregates and particle size selection for chemical analyses of nutrients and water-borne sediments. Results from sediments in lentic and lotic environments from the Salto System show that the larger aggregates (465 - 63 μm) concentrate nitrogen under lentic conditions and that, therefore, analyses should be performed on the fraction smaller than 465 μm in lentic environments and in the fraction ≤ 63 μm in lotic environments. The final objective of this study was to test the effects of oxidation on the phosphate sorption capacity and rate in organic aquatic sediments, identifying the best conditions for retention. Silicate aquatic sediments from different origins in terms of climate and source of organic content (allochtonous or autochtonous) were used, and were represented by the types Dy (Divisa Reservoir, RS) and Sapropel (Tapacurá Reservoir, São Lourenço da Mata, PE), respectively. The experiment was carried out in suspended sediment maintained under levels of redox potential between –200mV and +400mV. Results demonstrated that phosphate sorption is greatest in sediment type Dy under reduced conditions and in Sapropel under oxidized conditions.

Thesis (MSc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Water-borne coatings often contain multiple additives including pigments, dispersing agents, rheology modifiers, UV stabilizers and biocides. Due to their low molar mass and endocrinedisrupting properties, many of these additives, upon leaching from the substrate film, with time pollute water systems and become hazardous to the environment and to human health. In this study, I aimed to develop a facile method for the production of a polymeric biocide to serve as alternative to low molar mass biocides used in water-borne coatings. A secondary aim was to show that, without additional modification, the polymeric species can be used in surfactant-free ab initio emulsion polymerizations. Using a two-step process, I modified a commercially available copolymer, poly(styrene-alt-maleic anhydride) (SMA 1000), with mixed amines in order to obtain latexes with inherent antimicrobial activity. In the first step, I reacted SMA 1000 with 3-dimethylamino-1-propylamine and aqueous ammonia to confer antimicrobial activity and water-solubility to the SMA copolymer. In the second step, the copolymer was incorporated into a film-forming styrene-butyl acrylate (STY/BuA) latex. The modified SMA was incorporated into a latex in two ways: (1) post-added to the latex, and (2) used as stabilizer in emulsion polymerization. In both cases, the latex remained stable for up to 11 months, and stability was probably due to steric stabilization of the polymer particles. Antimicrobial activity of the latex film was achieved with both methods. When the modified SMA was post-added, antimicrobial activity was restricted to specific areas on the eventual polymer film, and when modified SMA was used as stabilizer, antimicrobial activity was evenly distributed throughout the polymer film. Fluorescence microscopy showed homogeneous distribution of antimicrobial activity upon inoculation in Gram positive bacteria dispersions when the modified copolymer was used as polymeric stabilizer for the synthesis of STY/BuA latexes. No antimicrobial activity against Gram negative bacteria was achieved. The homogeneous distribution of antimicrobial activity throughout the film was a result of adsorption of polymeric biocide/stabilizer to each individual latex particle. With further commercial development, high molar mass copolymers modified for antimicrobial activity may be a feasible, environmentally-friendly and healthy alternative to be used as stabilizers in emulsion polymerizations to produce water-borne coatings. / AFRIKAANSE OPSOMMING: Waterverf bestaan gewoonlik uit ‘n verskeidenheid bestandele, onder andere: pigmente, verspreiding middels, reologie modifiseerders, UV stabiliseerders en biologies aktiewe verbindings. As gevolg van die lae molêre massa en die endokrien ontwrigtende vermoë van baie van die bestandele hou hulle ‘n bedreiging in vir die omgewing in terme van waterbesoedeling en menslike gesondheid, soos hulle die film oor tyd verlaat. In hierdie studie het ek beoog om ‘n eenvoudige metode vir die vervaardiging van ‘n polimeries biologies aktiewe verbindings daar te stel om sodoende as ‘n alternatief vir die lae molêre massa biologies aktiewe verbindings, wat tans in waterverf gebruik word, te dien. ‘n Sekondêre uitkoms van die studie was om te wys dat, sonder enige adissionele omskakelings, dieselfde polimeer gebruik kan word in seep-vrye emulsie polimerisasie. Deur gebruik te maak van ‘n proses, wat uit twee stappe bestaan, het ek ‘n kommersieel beskikbare kopolimeer, poly(stireen-alt-maleinesuuranhidried) (SMA 1000), met gemengde amiene reageer om ‘n sintetiese lateks van stireen en butiel akrilaat (STY/BuA) met inherente antibakteriële aktiwiteit te verkry. In die eerste stap is SMA 1000 met 3-dimetielamien-1-propielamien en waterige ammoniak reageer om ‘n water oplosbare kopolimeer met inherente anti-bakteriële aktiwiteit te verkry. In die tweede stap is hierdie kopolimeer by ‘n sintetiese lateks gevoeg op twee maniere: (1) deur dit nadat die lateks geproduseer is by te voeg, en (2) deur die kopolimeer as stabiliseerder te gebruik in die vervaardiging van die lateks. In albei gevalle is stabiele latekse verkry vir ‘n tydperk van tot 11 maande. Die stabilisering was van steriese geaardheid. Albei die latekse het gevolglik antibakteriële eienskappe getoon. Daar was nie homogene verspreiding van die aktiwiteit in die geval waar die kopolimeer na die tyd bygevoeg is nie en het veroorsaak dat daar sekere areas van die finale film was wat geen aktiwiteit getoon het nie. Fluoresensie mikroskopie het egter homegene verspreiding van die anti-bakteriële aktiwiteit reg deur die film getoon, na inokulasie met Gram positiewe bakterië suspensies wanneer die kopolimeer as polimerisasie stabiliseerder gebruik was. Geen aktiwiteit teen Gram negatiewe bakterië was egter verkry nie. Die homogene verspreiding was as gevolg van die feit dat die kopolimeer sterk adsorbeer op elke individuele lateks partikel wanneer dit as stabiliseerder gebruik word. Verdere ontwikkeling op ‘n kommersiële basis kan daartoe lei dat polimeries biologies aktiewe verbindings as ‘n lewensvatbare en omgewingsvriendelike alternatief vir heidige stabiliseerders in emulsies vir waterverf gebruik kan word.

Orientador: Sandra Elisa Contri Pitton / Banca: Ana Tereza Caceres Cortez / Banca: Amanda Erica Domingos / Resumo: A forma pela qual os recursos hídricos são utilizados vem degradando os mananciais a um nível tal que se compromete a qualidade de vida das populações. Exauridos pela atividade antrópica, esse fato pode se tornar, no futuro, causador de conflitos. O setor de saneamento básico, sendo um dos que mais se utilizam dos recursos hídricos, é parte de fundamental importância no sentido de promover a melhoria da qualidade de vida da população, utilizando os recursos hídricos de maneira ambientalmente sustentável e garantindo os serviços de abastecimento de água e esgotamento sanitário, mesmo no cenário atual de crescente urbanização, quando se enfrenta a falta de recursos suficientes para expansão dos serviços e a ineficiência no uso dos recursos arrecadados no setor. No quadro dessa problemática, este estudo analisa o espaço urbano da zona leste de Teresina, focalizando o saneamento básico em seus bairros no que diz respeito à problemática dos serviços de abastecimento de água, esgoto sanitário e coleta de lixo. Verifica-se que as camadas mais pobres da população são as que mais sofrem as conseqüências da falta de infraestrutura desses serviços, com a ocorrência de doenças como hepatite e enteroinfecções, contribuindo para a redução da qualidade de vida da população e evidenciando ainda a segregação social existente entre os bairros de uma mesma região da cidade / Abstract: The way in which water resources are used is degrading the water sources at a level that compromises the quality of life of populations. Depleted by human activity, this may become in the future, causing conflicts. The basic sanitation sector, being one of the most use of water resources, is part of fundamental importance to improving the quality of life of the population using water resources in an environmentally sustainable manner and ensuring the supply services water and sanitation, even in the current scenario of increasing urbanization, when faced with the lack of sufficient resources for expansion of services and inefficiency in the use of funds raised in the industry. As part of this problem, this study examines the urban spaces of the east side of Teresina, focusing on sanitation in their neighborhoods with respect to the issue of services of water supply, sewage and garbage collection. It appears that the poorest of the population are the ones that suffer the consequences of lack of infrastructure such services, with the occurrence of diseases like hepatitis and enteroinfecções, contributing to reduced quality of life of people and showing also the social segregation between the neighborhoods of the same region of the city / Mestre

<p>Flexographic printing is a common printing method in the packaging field. The printing method is characterized primarily by the flexible printing plate and the low viscosity inks which make it suitable for use on almost any substrate. The object of this study was to obtain further knowledge of the some important mechanisms of flexographic printing and how they influence the print quality. The thesis deals with printing primarily on board and liner but also on newsprint with water-borne ink using a full-scale flexographic central impression (CI) printing press. Several printing trials have been performed with a focus on the chemical interaction between the ink and substrate and the physical contact between the ink-covered printing plate and the substrate.</p><p>Multicolour printing exposes the substrate to water from the water-containing ink. The emphasis was to investigate the relation between print quality and water-uptake of the paper surface with heat and water. Printing trials was carried out on substrates possessing a hydrophobic, and also a rather hydrophilic surface using a regular commercial water-borne ink. The favorable effect which water or surfactant solution had on the hydrophobic substrate with regard to print mottle could depend on its surface compressibility in combination with the hydrophobic nature of its surface that could affect the wetting properties.</p><p>Conventional printing involves physical contact between plate and ink and between ink and substrate. A method for measuring the dynamic nip pressure using thin load cells is presented. Print quality was influenced by the plate material. A correction procedure taking into account the size of the sensor was developed in order to estimate the maximum dynamic pressure in the printing nip. An attempt was made to identify essential mechanical and chemical parameters, and also geometrical properties of the plate that affected print quality. Laboratory printing trials were carried out and a multivariate analysis was applied for evaluation of print quality data. The impact of the plate properties on print quality was evident. The essential properties of the plate that influence print quality were the small-scale roughness and long-scale roughness.</p>

In this research water dispersed epoxy varnishes were produced by reacting solid epoxy resin with ethylene diamine (EDA) and maleinized fatty acids of linseed oil. Maleinized fatty acid (MFA) was produced by the maleinization process, in which, fatty acid and maleic anhydride were reacted under nitrogen atmosphere. Maleinization was performed in order to insert hydrophilic groups to the fatty acid chains, which were then inserted to the backbone of the epoxy resin. This was done to give water dispersibility to the hydrophobic epoxy resin. Solid epoxy resin was dissolved in 1,4-dioxane. Ethylene diamine was then added to the solution at 50&deg / C, and stirred for 4 hours. Then the temperature was increased to 80oC and kept for 2 hours. Maleinized fatty acids were then introduced, and the reaction was carried out at 90oC for 10 hours. 1,4-dioxane was used for the removal of the water, which forms as the byproduct. Then the driers were added. The carboxylic groups of the maleinized fatty acid were neutralized by morpholine and the product was dispersed in water. The varnish was applied on test panels and left for air-drying for 24 hours and then baked at 140&deg / C for 5 hours. The free epoxy content was determined by pyridinium-chloride titration and it was seen that all the epoxy groups reacted. Also, produced fatty acid was characterized by FTIR spectroscopy and maleinized fatty acid was characterized by H-NMR and FTIR spectroscopy. Hardness, bending, impact resistance, gloss, and abrasion resistance tests were carried out on hardened varnish specimens. The samples generally showed good mechanical and physical properties. While the baking time was increased the hardness of product increased. Samples showed superior impact resistance, gloss, and flexibility.