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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Adsorption of sulfate and phosphate at the mineral-water interface: isotherm, stoichiometry, and models

He, Liming 10 November 2005 (has links)
Processes occurring at mineral-water interfaces play critical roles for regulating the composition of surface and groundwater, for soil development, and for the availability of plant nutrients. Sulfate adsorption at three pH levels was conducted on y-AI203 and kaolinite. The adsorption isotherms were described well by the simple Langmuir, two-site Langmuir, Freundlich, and Temkin equations. The capacity of SO42-adsorption for y-AI203 was five times greater than for kaolinite, indicating the difference in reactive site density between y-Ab03 and kaolinite. Mathematical analyses for the adsorption isothenns demonstrated that S042- may not be adsorbed on the d-plane, i.e., in the diffuse layer, whereas both outer- and inner-sphere complexation mechanisms predicted S042- adsorption equally well. / Ph. D.
2

Sustainable Management of Central Victorian Mineral Waters

Shugg, Andrew James., ashugg@skm.com.au January 2005 (has links)
#DEFAULT
3

Charge Development at Iron Oxyhydroxide Surfaces : The Interplay between Surface Structure, Particle Morphology and Counterion Identity

Kozin, Philipp A. January 2014 (has links)
Iron (oxyhydr)oxide (FeOOH) minerals play important roles in various natural, technological and societal settings. The widespread abundance of these minerals has prompted numerous studies on their surface reactivity in aqueous media. Surface charge development, one that namely takes place through the adsorption of potential determining ions (p.d.i.; H+, OH-) and coadsorption of counterions (e.g. Cl-, ClO4-, Na+), is particularly interesting in this regard. Mineral surface charge development is determined by numerous factors related to the interplay of mineral surface structure, particle morphology and counterion identity. In this thesis the interplay between these factors is resolved by monitoring charge development on submicron-sized synthetic iron oxyhydroxide particles of different structures and sizes in aqueous media with counteranions of contrasting charge-to-size ratio (i.e. NaCl, NaClO4). This work, which is summarized in an introductory chapter and detailed in five appendices, is focused on three types of synthetic lepidocrocite (ã- FeOOH) of different shapes and surface roughness, three types of goethite (á-FeOOH) of different levels of surface roughness, and finally akaganéite (â-FeOOH), a mineral representing unique ion exchange properties due to its hollandite-type structure. While charge development was chiefly monitored by high precisition potentiometric titrations, these efforts were supported by a range of techniques including electrolyte ion uptake by cryogenic X-ray photoelectron spectroscopy, particle imaging by (high resolution) transmission electron microscopy, porosity analysis by N2 adsorption/desorption, surface potential development by electrokinetics, as well as thermodynamic adsorption modeling. These efforts showed that lepidocrocite particles of contrasting morphology and surface roughness acquired highly comparable pH and ionic strength p.d.i. loadings. Equilibriation times required to develop these loadings were however altered when particles became aggregated by aging. Goethite particles of contrasting surface roughness also acquired incongruent p.d.i. loadings, which were predominantly explained by the different charge-neutralizing capabilities of these surfaces, some of which were related to pore size distributions controlling the entrance of ions of contrasting sizes. Such size exclusion effects were also noted for the case of akaganéite where its bulk 0.4×0.4 nm wide channels permitted chloride diffusion but blocked perchlorate. Charge development at goethite surfaces in binary mixtures of NaCl and NaClO4 solutions also showed that the larger size-to-charge ratio chloride ion exerted a strong effect on these results even when present as a minor species. Many of these aforementioned effects were also modeled using variable, counterion- and loading-specific, Stern layer capacitance values. The findings summarized in this thesis are providing a better understanding of surface processes occurring at iron oxyhydroxide surfaces. They should impact our ability in designing uses of such particles, for example, effective sorption in aquatic media, as well as to understand how they behave in natural systems.
4

Determinação do limiar de detecção absoluto e avaliação dos niveis residuais de acetaldeido em aguas minerais acondicionadas em garrafas de polietileno tereftalato (PET) / Determination of the absolute threshold of detection and evaluation of trace levels of acetaldehyde in mineral water

Duarte, Gisele Mara Bertolazzo 28 July 2018 (has links)
Orientador: Carlos Alberto R. Anjos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-28T20:55:36Z (GMT). No. of bitstreams: 1 Duarte_GiseleMaraBertolazzo_M.pdf: 5637351 bytes, checksum: 31cc0c411ac10a3fe95906ed0b2bb30b (MD5) Previous issue date: 2001 / Resumo: O consumo de águas minerais no Brasil vem aumentando significativamente nos últimos anos. Os consumidores estão se tornando mais exigentes em relação aos hábitos de compra, qualidade, praticidade e conveniência. Dentro deste cenário e devido a uma série de vantagens técnicas e comerciais, as embalagens tradicionais de vidro, polietileno de alta densidade (PEAD) e policloreto de vinila (PVC) para águas minerais vem sendo substituídas pelas embalagens de polietileno tereftalato (PET). A resina de PET é susceptível à termodegradação durante o processo de injeção de pré-formas, ocorrendo a formação de acetaldeído que pode alterar o aroma e sabor de águas minerais e diversos outros produtos acondicionados em embalagens de PET, dependendo dos níveis existentes deste composto. Todos os setores envolvidos na fabricação de garrafas de PET, tais como fabricantes de resinas, pré-formas, garrafas e de equipamentos, vem trabalhando em conjunto com o objetivo de minimizar a formação de acetaldeído durante o processo de fabricação. Muitas dessas empresas possuem dados relativos aos seus processos, porém não são divulgados ao público. Por outro lado, as empresas envasadoras de águas minerais preocupam-se e desconhecem os níveis residuais de acetaldeído capazes de promover alteração de sabor e aroma, em seus produtos, comprometendo a qualidade após o envase. O presente trabalho teve como objetivos principais determinar o limiar de detecção ou threshold absoluto de acetaldeído em águas minerais, ou seja, determinar a concentração mínima de acetaldeído que promove diferença sensorial significativa, medir os níveis residuais de acetaldeído, através de cromatografia a gás em diferentes águas de fontes brasileiras acondicionadas em PET e verificar se as mesmas apresentam diferença sensorial significativa quando comparadas com as respectivas águas envasadas em garrafas de vidro / Abstract: The consumption of mineral water in Brazil has been increasing significantly in the last few years. Consumers are becoming more demanding with respect to their buying habits and convenience for use. Due to a series of technical advantages the traditional glass package, high-density polyethylene and PVC for mineral waters have been replaced by the PET package. The PET resin is susceptible to thermal degradation during the injection process, resulting in the formation of acetaldehyde, which can alter the flavor of the mineral waters and many other products packaged in PET. Many sectors involved in the production of PET bottles, like the resin producers, pre forms, bottles and equipment producers have been working together aiming to minimize the formation of acetaldehyde during the production processo On the other hand, the mineral water companies are concerned about the residuallevels of acetaldehyde that can promote flavor modification in their products, which could compromise the quality of the product after bottling. The present work aimed at determining the absolute acetaldehyde lhreshold in mineral water and acetaldehyde residue using gas chromatography in different brands, packaged in PET bottles. Also, to verify if the mineral water bottled in PET bottles showed any significant sensory difference when compared with the same waters packaged in glass bottles / Mestrado / Mestre em Tecnologia de Alimentos
5

Impact of Sex and Rehydrating Fluid on Parameters of Dehydration, Rehydration, and Athletic Performance

Harris, Preston Royal, Harris, Preston Royal January 2017 (has links)
Background: In humans, total body water volume and osmolality are tightly regulated by various homeostatic mechanisms, triggered by deviations in osmolality. Heat and exercise are two stressors, which in combination can cause dehydration, and an increase in fluid osmolality, contributing to health detriments, as well as deficits in aerobic exercise performance. However, it is unclear whether dehydration affects muscular strength. Deep-ocean mineral water has been shown to have benefits on various physiological and pathophysiological conditions, including aerobic performance and muscle strength. Objectives: The aims of this study were to examine any sex differences that may exist in response to dehydration of 3% of body mass, rehydration with various fluids, and the consequences of dehydration and rehydration on muscle power and hydration status. Design: We used a counterbalanced, crossover study design, in which subjects (n=17, 9 males vs 8 females) performed a dehydrating exercise protocol until achieving a 3% body mass loss, and then rehydrated with either deep-ocean mineral water (Deep), mountain spring water (Spring), or a carbohydrate-based sports drink (Sports). Subjects completed the protocol three times, with each subject receiving the rehydrating fluid in a different order to control for order effects. Saliva samples were collected throughout the protocol to measure osmolality, and muscle strength was measured by peak torque leg extension at baseline, post-exercise, and post-rehydration. Results: We found no differences between men and women in baseline or peak salivary osmolality, or in the exercise-induced increase in osmolality. Male subjects took less time to reach 3% body mass loss than females, and females demonstrated lower sweat rates than males. Salivary osmolality returned to baseline after rehydration, with the Deep group exhibiting a significantly more rapid return to baseline, for both sexes, compared to Sports and Spring. Males generated greater peak torque extension than females at baseline, while both males and females displayed a similar significant deficit in this measure following dehydration. Peak torque recovery post-rehydration was significantly affected by fluid designation and sex, and a significant difference was seen between the Deep and the Sports groups in females. Conclusions: Males reached 3% body mass loss faster than females, while dehydration resulted in increased salivary osmolality and muscle strength deficits similarly for males and females. Deep-ocean mineral water had a significant beneficial effect on hydration recovery, for both males and females, compared to the other fluids. Recovery of muscle strength after rehydration was affected by fluid and sex, with the main driver being females.
6

Vliv srážek na mělké jímání minerálních vod / The influence of precipitation on shallow mineral water abstraction

Hlaváčová, Michaela January 2014 (has links)
This study focuses on the influence of precipitation on shallow catchments of mineral springs in the special area of Františkovy Lázně. The thesis was made on the basis of the data provided by the company Spa Františkovy Lázně a.s.. The interdependent relations between yield springs, precipitations, atmospheric pressure and the content of free CO2 were studied. These relations were observed onto six springs - František, Luční, Nový, Solný, Železnatý and Žofie. The precipitations were compared with the yield of individual springs. The season was proved by three springs (František, Železnatý and Žofie). Retention of the precipitation was determined for springs František, Solný, Železnatý and Žofie. Considering more than half a year delay, we cannot claim that the precipitations should have a major influence on the dotation of mineral springs. The downtrend was founded for the free CO2 in all researched resources. Significant indirect relation was found using the correlation coefficient between atmospheric pressure and free CO2.
7

Águas minerais em São Paulo. / Evaluation of the impact of induction motors in electrical distribution networks and a regulation proposal to their access to low voltage networks.

Luiz, Thays de Souza João 06 August 2009 (has links)
Este trabalho objetiva traçar um breve panorama das Águas Minerais exploradas no Estado de São Paulo. Por meio deste trabalho será estudada a importância da exploração das Águas Minerais para o Estado de São Paulo e para o todo o país. Muitas modificações ocorreram no Mercado de Águas Minerais que em 1980 era praticamente desconhecido. Esta dissertação dará maior ênfase às modificações que ocorreram na última década que foram muito significativas tanto para o minerador como para o consumidor.Serão vistos os tipos de produtos que as empresas de Água Mineral costumam comercializar e as exigências e expectativas do consumidor com relação aos produtos de água mineral. Devido à importância da água mineral nos dias de hoje tanto como recurso hídrico, como bem mineral; este trabalho estuda o atual Mercado de Águas e até se permite fazer breves previsões futuras. / This work as aim to draw a brief panorama of Drinking Waters that are explored in the state of São Paulo. Through this work will be studied the importance of the exploration of Drinking Waters for the São Paulo state and for the whole country. Several changes occurred in the Market of Mineral Water that in 1980 it was practically unknown. This dissertation will emphasize the changes which happened in the last decade which were meaningful for the miner and for the customer. They will be seen the kind of products that the Mineral Water companies use to commercialize and the exigencies and expectations of the consumers with relation at the Mineral Water products. Nowadays, due to the importance of Mineral Water as such a hydraulic resource and as a mineral resource, this work studies the actual Market of Mineral Water and it lets itself to make future predictions about this market.
8

ÁGUAS SUBTERRÂNEAS ENRIQUECIDAS NATURALMENTE DE MINERAIS: AVALIAÇÃO DO POTENCIAL MEDICINAL.

Rocha, Thaisa Borges 24 April 2009 (has links)
Made available in DSpace on 2016-08-10T10:53:48Z (GMT). No. of bitstreams: 1 THAISA BORGES ROCHA.pdf: 749050 bytes, checksum: 3eb120b6829c11cadc85a03cfc4b1c30 (MD5) Previous issue date: 2009-04-24 / The excess of minerals or their deficiency, associated with poor diets can lead to a deviation of the values of micronutrients considered normal for a given population, allowing the emergence of various diseases. Among the possible ways of ingesting minerals are mineral waters, and the chemical composition of mainly controlled by the mineralogy of rocks and sediment. In Brazil, the ordinance MS / 917 2006, found that the hydrotherapy social)/ water therapy is an indication of recognition and use of mineral waters in a manner complementary to other treatments and health that our country has natural and human resources to its ideals development in the SUS. Therefore, this study aimed to evaluate the levels of macro minerals and trace elements in samples of water naturally rich in minerals from ibirá-SP and a water supply system from the public in Goiânia-GO, with the basal level samples of distilled water , also evaluated the possible incorporation into macro minerals and trace elements in hair samples of rats after administration of environmental matrices of water from Ibirá-SP, Goiânia-GO and distilled, respectively, in addition to assessing the medicinal potential of macro minerals and trace elements present in water naturally enriched associated human health. The study shows difference in composition of macro minerais and trace elements in water depending on the origin of these, and shows different elements in hair samples of rats according to the source of the water consumed by the groups. From the data obtained is possible to suggest that consumption of water originating from Ibirá-SP bring increased concentrations of Ca, Mg and V body, and that this concentration is not toxic levels, the practice of consumption of such water may benefit to health, especially regarding the prevention of nephrolithiasis. In conclusion, more studies are needed to assess the potential of water originating from Ibirá-SP with regard to results. / O excesso de minerais ou a deficiência destes, associados a dietas pobres, podem levar a um desvio nas concentrações corporais destes consideradas ideais para uma determinada população, e aumentar o risco de desenvolvimento de diversas patologias. Dentre as formas possíveis de ingestão de minerais estão as águas minerais, sendo a composição química destas controlada principalmente pela mineralogia das rochas e dos sedimentos pelos quais perpassam. No Brasil, a portaria MS / 917 de 2006, considerou que o termalismo social / crenoterapia constitui uma abordagem reconhecida de indicação e uso de águas minerais de maneira complementar aos demais tratamentos de saúde e que nosso país dispõe de recursos naturais e humanos ideais para seu desenvolvimento no SUS. Assim, este estudo objetivou avaliar os níveis de macrominerais e elementos traço em amostras de água naturalmente enriquecidas de minerais procedentes de Ibirá-SP e de águas procedentes do sistema de abastecimento público de Goiânia-GO, tendo como nível basal amostras de água destilada; também teve como objetivo avaliar a possível incorporação de macrominerais e elementos traço em amostras de pêlos de ratos após administração das matrizes ambientais de águas de Ibirá-SP, Goiânia-GO e destilada, respectivamente; além de avaliar o potencial medicinal dos macrominerais e elementos traço presentes nas águas naturalmente enriquecidas associado a saúde humana. O estudo aponta diferença de composição de macrominerais e elementos traço em águas dependendo da origem destas, assim como mostra diferença de elementos nas amostras de pêlos de rato de acordo com a origem da água consumida pelos grupos. A partir dos dados obtidos é possível sugerir que o consumo da água originária de Ibirá-SP traga aumento das concentrações de Ca, Mg e V corporais, e que o consumo de águas originárias desta fonte em concentrações consideradas não tóxicas poderá trazer benefícios para saúde, principalmente em relação a prevenção de nefrolitíase. No entanto, são necessários mais estudos para avaliar a potencialidade medicinal da água originária de Ibirá-SP com relação aos resultados encontrados.
9

Qualidade microbiológica da água mineral engarrafada e seu potencial como fonte de bactérias resistentes a antibióticos

Dias, Maria Fernanda Falcone [UNESP] 30 March 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-03-30Bitstream added on 2014-06-13T21:02:01Z : No. of bitstreams: 1 dias_mff_dr_arafcf.pdf: 650990 bytes, checksum: e8387e9814bf01f763121fa48d5fdae2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O uso da contagem de heterotróficos em placa (CHP) como um parâmetro de qualidade para águas minerais engarrafadas ainda requer atenção e a variação quantitativa das bactérias durante a estocagem dessas águas precisa ser melhor entendida. Além disso, a hipótese da água mineral representar uma fonte de bactérias resistentes a antibióticos, dada a possibilidade de transmissão direta aos humanos, é preocupante. Este trabalho foi dividido em três capítulos; no primeiro capítulo temos uma introdução geral e revisão de literatura e no segundo e terceiro capítulos apresentamos os artigos resultantes das pesquisas realizadas. No segundo capítulo nosso trabalho teve como objetivo detectar variações quantitativas na CHP e na presença de microrganismos indicadores durante o período de validade de águas minerais brasileiras. Nenhuma variação foi detectada na presença de microrganismos indicadores (E. coli, coliformes totais, P. aeruginosa e enterococos), mas variações na CHP foram observadas em algumas marcas, o que sugere que a qualidade dessas águas podem estar sofrendo alterações. Embora nenhum limite seja estabelecido para CHP em água mineral, este estudo se baseou no limite de 500 unidades formadoras de colônias por mL de amostra (UFC/mL) e setenta e duas garrafas (22,22%) apresentaram níveis acima deste limite com valores de até 560.000 UFC/mL. Este estudo mostrou que o controle da CHP (<500 UFC/mL) em embalagem não retornável parece ser adequado para garantir a qualidade da água mineral durante o armazenamento. Os elevados valores de CHP e suas variações detectadas durante o armazenamento parecem justificar a necessidade de uma reavaliação do uso da CHP na gestão da qualidade da água mineral. Além disso, estudos mais detalhados sobre o risco... / The use of heterotrophic plate count (HPC) as a quality parameter for bottled mineral water still requires attention and the variation of the bacteria during storage of these waters must be better understood. Furthermore the hypothesis that bottled mineral waters may represent a source of antibiotic resistant bacteria, given the possibility of direct transmission of bacteria to humans is worrying. This work was divided into three chapters, the first chapter we have a general introduction and review of literature and the second and third chapters present the articles. In the second chapter of our work aimed to detect quantitative variations in the HPC and in the presence of indicator microorganisms during their shelf life of Brazilian mineral water. No variations were identified in the presence of indicator microorganisms (E. coli, coliformes totais, P. aeruginosa and enterococos), but variations in HPC were observed in some brands, which suggests that changes may be occurring in the water quality during storage. Although no limit is set for HPC in mineral water, this study relies on the limit of 500 colonyBforming units per mL of sample (CFU/mL) and seventyBtwo bottles presented levels above this limit and up to 560,000 CFU/mL. This study showed that the control of HPC (< 500 CFU/mL) for nonBreturnable packaging seems to be adequate to ensure the quality of mineral water during storage. The high values of HPC and the variations detected during storage seem to fully justify the need for a reevaluation of the use of HPC in bottled mineral water quality management. Furthermore, more detailed studies... (Complete abstract click electronic access below)
10

Qualidade microbiológica da água mineral engarrafada e seu potencial como fonte de bactérias resistentes a antibióticos /

Dias, Maria Fernanda Falcone. January 2012 (has links)
Orientador: Adalberto Farache Filho / Banca: Clarice Queico Fujimura Leite / Banca: João Bosco Faria / Banca: Clóvis Wesley Oliveira de Souza / Banca: Suzana Segura Muñoz / Resumo: O uso da contagem de heterotróficos em placa (CHP) como um parâmetro de qualidade para águas minerais engarrafadas ainda requer atenção e a variação quantitativa das bactérias durante a estocagem dessas águas precisa ser melhor entendida. Além disso, a hipótese da água mineral representar uma fonte de bactérias resistentes a antibióticos, dada a possibilidade de transmissão direta aos humanos, é preocupante. Este trabalho foi dividido em três capítulos; no primeiro capítulo temos uma introdução geral e revisão de literatura e no segundo e terceiro capítulos apresentamos os artigos resultantes das pesquisas realizadas. No segundo capítulo nosso trabalho teve como objetivo detectar variações quantitativas na CHP e na presença de microrganismos indicadores durante o período de validade de águas minerais brasileiras. Nenhuma variação foi detectada na presença de microrganismos indicadores (E. coli, coliformes totais, P. aeruginosa e enterococos), mas variações na CHP foram observadas em algumas marcas, o que sugere que a qualidade dessas águas podem estar sofrendo alterações. Embora nenhum limite seja estabelecido para CHP em água mineral, este estudo se baseou no limite de 500 unidades formadoras de colônias por mL de amostra (UFC/mL) e setenta e duas garrafas (22,22%) apresentaram níveis acima deste limite com valores de até 560.000 UFC/mL. Este estudo mostrou que o controle da CHP (<500 UFC/mL) em embalagem não retornável parece ser adequado para garantir a qualidade da água mineral durante o armazenamento. Os elevados valores de CHP e suas variações detectadas durante o armazenamento parecem justificar a necessidade de uma reavaliação do uso da CHP na gestão da qualidade da água mineral. Além disso, estudos mais detalhados sobre o risco... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of heterotrophic plate count (HPC) as a quality parameter for bottled mineral water still requires attention and the variation of the bacteria during storage of these waters must be better understood. Furthermore the hypothesis that bottled mineral waters may represent a source of antibiotic resistant bacteria, given the possibility of direct transmission of bacteria to humans is worrying. This work was divided into three chapters, the first chapter we have a general introduction and review of literature and the second and third chapters present the articles. In the second chapter of our work aimed to detect quantitative variations in the HPC and in the presence of indicator microorganisms during their shelf life of Brazilian mineral water. No variations were identified in the presence of indicator microorganisms (E. coli, coliformes totais, P. aeruginosa and enterococos), but variations in HPC were observed in some brands, which suggests that changes may be occurring in the water quality during storage. Although no limit is set for HPC in mineral water, this study relies on the limit of 500 colonyBforming units per mL of sample (CFU/mL) and seventyBtwo bottles presented levels above this limit and up to 560,000 CFU/mL. This study showed that the control of HPC (< 500 CFU/mL) for nonBreturnable packaging seems to be adequate to ensure the quality of mineral water during storage. The high values of HPC and the variations detected during storage seem to fully justify the need for a reevaluation of the use of HPC in bottled mineral water quality management. Furthermore, more detailed studies... (Complete abstract click electronic access below) / Doutor

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