This thesis describes an investigation of corrosion processes occurring under thin polymeric layers (3 -5 mum) and suggests ways by which the films suppress the onset of corrosion of the bulk metal in corrosive aqueous environments. Synthetic solutions have been developed which replicate pH and conductivity conditions, likely to be found in beverage cans and which have been used to conduct corrosion studies of commercial lacquer systems. Studies carried out highlight the following points: i) The degree and nature of the film cross-linking has a role in the anti-corrosive action of the films. ii) The quantity of iron released into the beverage is much lower than expected when the corrosivity of the solution and the relative thinness of the film are considered. Work carried out indicates a possible means by which the iron might be complexed by the phenolic cross-linker component of the film with evidence having been obtained showing the ease with which phenolic cross-linker/iron complexes can be formed. iv) Optical Emission Glow discharge spectrometry has provided evidence that iron corrosion products are trapped within the polymer matrix. The work has also highlighted a means of accurately determining the film thickness. v) Water permeation across the cured films was followed using infra-red spectroscopy. The amount of water at found to migrate across films of different cross-linking densities was observed to vary with phenolic cross-linker level present vi) Permeation of ions across cured films has been followed with the use of ion selective electrodes. The films have also been shown to be perm-selective towards the diffusion of sodium ions in preference to chloride ions, in aqueous sodium chloride solutions, thus exhibiting a duality in the nature of the coatings towards the constituents of corrosive environments. vi) Alternating Current Impedance spectroscopy, has been used to observe the electrolyte penetration and corrosion initiation processes, in situ. A knowledge of the electrochemical processes occurring for these water-based epoxy-acrylate films during electrolyte penetration, saturation of the film and development of corrosion underneath the film has been obtained.

Made available in DSpace on 2014-10-09T12:55:08Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:57Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Thesis (MTech (Biomedical Technology))--Cape Peninsula University of Technology, 2009. / In recent years antioxidants present in various beverages have attracted a great deal of research interest due to their potential benefits to human health. Epidemiological evidence shows an indirect relationship between the intake of beverages rich in antioxidants and the reduced incidences of some chronic diseases, certain cancers and coronary heart disease mortality. The study was divided into two phases. The aim of the first phase was to compile a database of antioxidant capacities (Oxygen radical absorbance capacity, Ferric reducing antioxidant potential and Trolox equivalent antioxidant capacity) and contents (polyphenols, flavonols, flavanols, anthocyanins and vitamin C) of selected South African beverages. The second phase of the project included an intervention study to investigate the short term in vivo effects of consumption of an antioxidant-rich beverage, rooibos, on the antioxidant and oxidative stress status of human participants. The parameters that were investigated in human plasma included the total antioxidant capacity (ORAC and FRAP) and content (total polyphenols) as well as the reduced-oxidised glutathione ratios (GSH/GSSG) in erythrocytes. Results from this study were used to compile a database for antioxidant capacities and contents of selected South African beverages. The results showed that, in the case of fruit juices their antioxidant capacity and content covered a wide range. This could be attributed to the juice's differences in fruit composition, e.g. either as a single fruit or as a combination of two or more fruits. In the case of wines, red wines had the highest antioxidant capacity for all the beverages tested and had 22 times higher polyphenols compared to that of white wines. Results also indicated that black tea and coffee had a higher antioxidant capacity and polyphenol content than the local herbal tea, rooibos. The duration of extraction (brewing) of the teas also influenced the antioxidant capacity. Correlations between the three antioxidant capacity assays were very high in the case of wines and teas, but lower in the case of fruit juices. This antioxidant database for South African beverages is useful not only to consumers, but also nutritionist, researchers, dieticians and functional food formulators.

Made available in DSpace on 2014-10-09T12:55:08Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:57Z (GMT). No. of bitstreams: 0 / Os materiais plásticos possuem papel importante na transformação do estilo de vida das pessoas e é cada vez mais utilizado na produção e consumo pela população mundial. O material plástico tornou possível o fenômeno do crescimento de produtos descartáveis. Como conseqüência desta conjuntura, a reciclagem desses materiais torna-se opção obrigatória da sociedade moderna. A economia proporcionada pela reutilização dos materiais reciclados é vantajosa não apenas em consideração à reutilização dos recursos naturais envolvidos nestes produtos, mas principalmente pelo beneficio proporcionado no que tange a preservação das questões ambientais. Dentro do grande universo dos plásticos e embalagens plásticas disponíveis no mercado atual, no decorrer deste trabalho, foi realizada a reciclagem mecânica das embalagens pós-consumo, produzidas a partir do polímero PET, e mais especificamente às garrafas utilizadas na embalagem de bebidas em geral como, por exemplo, bebidas carbonatadas, água mineral, isotônicos e similares. Portanto, o objetivo deste trabalho foi estudar a reciclagem do PET de origem pós-consumo, e avaliar os efeitos provocados pela ação de diferentes doses de radiação ionizante, nas propriedades deste polímero reciclado, tendo como referência o PET virgem. Com base nos resultados obtidos, concluiu-se que os efeitos provocados pela ação da radiação ionizante a partir de feixe de elétrons proveniente de aceleradores de elétrons e, raios gama emitidos por fonte de 60Co, promoveram a predominância das reações de cisão aleatória da cadeia principal do PET, com conseqüente queda da massa molar do polímero. Fato este comprovado pelos ensaios de índice de fluidez e viscosidade intrínseca. Também foi realizada a análise térmica por calorimetria exploratória diferencial (DSC) comprovando a diminuição da massa molar do PET irradiado. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

In this paper, the impact of caffeinated beverages on oral and systemic health was evaluated bringing to light a variety of outcomes. Coffee, tea and energy drinks are beverages that so many individuals around the globe consume in their daily lives yet the potential beneficial or adverse effects are rarely taking into consideration as drinks are consumed. These beverages cause positively influence antimicrobial, anti-cariogenic and anti-inflammatory responses on oral health yet there are also negative consequences that can arise. Society leads individuals to believe that these beverages are a necessity in people’s lives. Therefore, this thesis is written in hope to better understand the effects and impact these beverages have on the human body specifically the oral cavity. Some of these beverages, such as coffee and energy drinks, can have detrimental effects on oral health, teeth and systemic health. Outcomes from excessive intake of these drinks include dental erosion, cavities, and systemic health consequences. These types of beverages should be taken in moderation, otherwise negative effects can arise. On the other hand, sometimes caffeinated beverages can be beneficial to oral health such as when green or black tea are consumed. Considerable research has been performed to better understand the relationship between caffeinated beverages and how they influence the oral cavity. This thesis will evaluate this literature including both the positive and negative effects. With moderate intake, these types of beverages can play a beneficial role in oral and systemic health. In summary, studied have documented the significant beneficial effects of caffeinated beverages including tea, coffee and energy drinks on oral and systemic health. These benefits include antibacterial and anti-cariogenic effects in the oral cavity and improvement in cardiovascular health, metabolism, overcoming fatigue and anti-inflammatory properties with respect to systemic health. As with many things, high or excess intake of caffeinated products can lead to negative consequences such as increased risk of cardiovascular disease, loss of tooth integrity due to sugar and staining leading to tooth discoloration. Research has made great strides in understanding the oral and systemic effects of such beverages. However, there are still unanswered questions that should be pursued in order to truly elucidate the mechanism of action specifically related to the ingredients seen in caffeinated beverages

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Background: Between 1977 and 2002, the per capita intake of caloric beverages doubled in the United States, with most recent data from 2005–2006 showing that children and adults consume about 172 and 175 kcal daily, respectively, from sugar-sweetened beverages (SSB) (Brownell et al., 2009). Also, a high intake of SSB has been related to many adverse health outcomes including type 2 diabetes, obesity, dental carries and heart disease (Malik, Schulze, & Hu, 2006; Vartanian, Schwartz, & Brownell, 2007; Schulze et al., 2004; Ismail, Sohn, Lim, & Willem, 2009; Fung et al., 2009); however, few studies have explored factors that influence SSB consumption. In addition, no theory-based interventions have been implemented targeting this public health problem. Objective: The primary objective of this study was to apply the Theory of Planned Behavior (TPB) (Ajzen, 1991) to investigate culturally specific attitudes, subjective norms and behavioral capabilities related to SSB, water, and artificially sweetened drink consumption among adults residing in rural Southwest Virginia. In addition, programmatic issues related to implementation of SSB interventions, including small group sessions and interactive voice response (IVR) technology was explored. Methods: A total of 8 focus groups were completed with 54 participants. Each focus group took place with residents from one of the 11 identified rural Southwest Virginia counties. Four focus groups included individuals on city water and four contained residents on well water to investigate any discrepancies in attitudes, norms and perceived behavioral control related to the intake of various drinks. Participants needed to be at least 18 years of age, English speaking, and consume >1 cup of SSB per day. A semi-structured script guided by the TPB constructs was used to facilitate the focus group discussions. All focus groups were transcribed verbatim. Two researchers independently reviewed the transcripts and met to identify major themes and develop a coding system. Three researchers independently coded meaning units (MU) to the major themes and subsequently met to review codes and reconcile disagreements. Results: The most notable themes that emerged included taste (n= 161 MU), availability/convenience (n= 95 MU), cost (n= 28 MU), and habit/addiction (n= 57 MU). Participants also continuously emphasized the importance of their doctor's advice and health concerns on their beverage choices. The majority of the participants (n=27 MU) indicated they would be willing to participate in a program with three small group sessions and phone calls, yet when asked specifically about receiving multiple interactive voice technology telephone messages, most participants said that they would not be receptive to an automated message (n=21 MU). Conclusions: Collectively, these findings provide unique cultural insight to better understand the salient beliefs associated with beverage behaviors and helps inform intervention development and delivery in the targeted vulnerable region of Southwest Virginia. / Master of Science

Purpose: This article examines changes in attitude and beverage consumption after a school-wide policy change replacing sweetened beverages in vending machines with 100% juice and bottled water. Methods: Written questionnaires were administered three times to high school students (n = 278) in an ethnically-diverse, southwest Virginia school district. X ² analysis was utilized and test-retest reliability was assessed with intra-class correlation coefficients. Results: Pearson correlation coefficients for reliability between test and re-test displayed a range from r =0.53 to r =0.73. There were no significant differences in demographics (gender and ethnicity) between time periods. X ² analysis revealed students were significantly more likely to choose healthier beverage vending options after one year compared to baseline (P<0.01). Although beverage vending purchases declined to near significance immediately following the change, there were no significant changes observed between baseline and follow-up (P<0.05). X ² analysis revealed no significant (P<0.05) changes in outside purchase patterns. Students also indicated that the top reasons for snack/beverage choices were hunger, taste, and price. Conclusion: This suggests that students purchase what is convenient and available, regardless of choices. Therefore, environmental changes may be beneficial to promote healthier beverage choices among adolescents.</p> / Master of Science