32 resultados para CONSUMER PRODUCTS
em Instituto Politécnico do Porto, Portugal
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Context: Some chemicals used in consumer products or manufacturing (eg, plastics, pesticides) have estrogenic activities; these xenoestrogens (XEs) may affect immune responses and have recently emerged as a new risk factors for obesity and cardiovascular disease. However, the extent and impact on health of chronic exposure of the general population to XEs are still unknown. Objective: The objective of the study was to investigate the levels of XEs in plasma and adipose tissue (AT) depots in a sample of pre- and postmenopausal obese women undergoing bariatric surgery and their cardiometabolic impact in an obese state. Design and Participants: We evaluated XE levels in plasma and visceral and subcutaneous AT samples of Portuguese obese (body mass index ≥ 35 kg/m2) women undergoing bariatric surgery. Association with metabolic parameters and 10-year cardiovascular disease risk was assessed, according to menopausal status (73 pre- and 48 postmenopausal). Levels of XEs were determined by gas chromatography with electron-capture detection. Anthropometric and biochemical data were collected prior to surgery. Adipocyte size was determined on tissue sections obtained during surgery. Results: Our data show that XEs are pervasive in this obese population. Distribution of individual and concentration of total XEs differed between plasma, visceral AT, and subcutaneous AT, and the pattern of accumulation was different between pre- and postmenopausal women. Significant associations between XE levels and metabolic and inflammatory parameters were found. In premenopausal women, XEs in plasma seem to be a predictor of 10-year cardiovascular disease risk. Conclusions: Our findings point toward a different distribution of XE between plasma and AT in pre- and postmenopausal women, and reveal the association between XEs on the development of metabolic abnormalities in obese premenopausal women
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International Congress Marketing Trends Annual Conference in Paris, 17 – 19 January 2013
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Dissertação apresentada ao Instituto Superior de Contabilidade e Administração do Porto para a obtenção do Grau de Mestre em Marketing Digital. Orientado por Mestre Inês Veiga Pereira
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Dissertação de Mestrado em Finanças Empresariais
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Dissertação apresentada ao Instituto Superior de Contabilidade e Administração do Porto para a obtenção do Grau de Mestre em Empreendedorismo e Internacionalização Orientada pela Mestre Maria Luísa Verdelho Alves
Resumo:
Cada vez mais começa a notar-se, na indústria vitivinícola, uma grande preocupação com a qualidade dos seus produtos, motivada pela maior sensibilização e exigência dos consumidores. Deste modo, a presença de defeitos organoléticos no vinho representa uma fonte de perda financeira nesta indústria, pelo que o seu controlo se torna indispensável para que se obtenha um produto de elevada qualidade. Neste sentido, torna-se interessante desenvolver um método de análise que seja rápido de forma a permitir a quantificação simultânea das moléculas identificadas como principais responsáveis pelos distúrbios olfativos dos vinhos. Assim, este trabalho surge com o objetivo de implementar e validar um método para a determinação de contaminantes em vinho por microextração em fase sólida (SPME) e cromatografia gasosa acoplada à espetrometria de massa tandem (GC-MS/MS) e a sua correlação com a análise sensorial. A técnica de microextração em fase sólida é simples e rápida na medida em que não requer um pré-tratamento da amostra. Por sua vez, a análise por GC-MS permite identificar de forma clara os compostos em estudo, nomeadamente, 4-Etilfenol (4-EP), 4-Etilguaiacol (4-EG), 2,4,6-Tricloroanisol (TCA), 2,3,4,6-Tetracloroanisol (TeCA) e 2,4,6-Tribromoanisol (TBA). Foram realizados estudos de otimização das condições de extração, comparando as fibras 100 μm PDMS e 50/30 μm DVB/CAR/PDMS. Obtiveram-se resultados mais satisfatórios, em termos de resposta e da relação sinal/ruído, com a fibra 50/30 μm DVB/CAR/PDMS e estabeleceram-se como condições de extração 55ºC para a temperatura de incubação/extração, uma velocidade de agitação de 250 rpm e 60 minutos de tempo de extração. Ao longo deste trabalho, analisaram-se 50 amostras de vinho, das quais 48 eram amostras de Vinho Tinto do Douro e 2 de Vinho do Porto. Para validar a metodologia foram realizados estudos de linearidade, limiares analíticos, repetibilidade, precisão intermédia e recuperação. De um modo geral, obtiveram-se bons resultados ao nível da linearidade para as gamas de concentração escolhidas. Quanto aos limites de deteção e de quantificação, o 4-EP é o contaminante que apresenta uma gama de concentrações mais alta, notando-se limiares analíticos mais elevados, com valores próximos dos últimos níveis de concentração, oscilando entre 65 e 583 μg/L. No caso dos Anisóis, o TBA apresenta limites de deteção mais baixos, entre 0,4 e 17,0 ng/L. Os limiares analíticos foram validados com recurso a estudos de precisão intermédia e repetibilidade, cujos resultados se encontram dentro das especificações descritas no documento SANCO/10684/2009 (%RSD ≤ 30% para os Anisóis e %RSD ≤ 20% para os Fenóis Voláteis). Foram, ainda, realizados estudos de exatidão recorrendo a ensaios de recuperação e a ensaios interlaboratoriais. Muitas vezes conseguem-se boas recuperações, no entanto notam-se maiores dificuldades para o TBA e para o TeCA. Relativamente aos ensaios interlaboratoriais, verificam-se maiores discrepâncias para o 4-EP. Já os restantes contaminantes apresentam resultados, geralmente, satisfatórios (|z-score| ≤ 2).
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The electrochemical behavior of the hydrolysis products of oxadiazon was studied by cyclic and square-wave voltammetry using a glassy carbon electrode. Maximum currents were obtained at pH 12.8 in an aqueous electrolyte solution containing 30% ethanol and the current did not decrease with time showing that there was little adsorption of the reaction products on the electrode surface. The hydrolysis products of oxadiazon were identi®ed, after isolation and puri®cation, as 1-trimethylacetyl-2-(2,4-dichloro-5-isopropoxyphenyl)-2-ethoxycarbonylhydrazine (Oxa1) and 1-trimethylacetyl-2-(2,4-dichloro-5-isopropoxyphenyl) hydrazine (Oxa2) with redox potentials 0.6Vand 70.1V (vs. Ag=AgCl), respectively. Based on the electrochemical behavior of 1-trimethylacetyl-2-(2,4-dichloro-5-isopropoxyphenyl) hydrazine (Oxa2) a simple electroanalytical procedure was developed for the determination of oxadiazon in commercial products used in the treatment of rice crops in Portugal that contain oxadiazon as the active ingredient. The detection limit was 161074 M, the mean content and relative standard deviation obtained for seven samples of two different commercial products by the electrochemical method were 28.4 0.8% (Ronstar) and 1.9 0.2% (Ronstar GR), and the recoveries were 100.3 5.4% and 101.1 5.3 %, respectively.
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The electrochemical behavior of citalopram was studied by square-wave and square-wave adsorptive-stripping voltammetry (SWAdSV). Citalopram can be reduced and accumulated at a mercury drop electrode, with a maximum peak current intensity being obtained at a potential of approximately -1.25V vs. AgCl/Ag, in an aqueous electrolyte solution of pH 12. A SWAdSV method has been developed for the determination of citalopram in pharmaceutical preparations. The method shows a linear range between 1.0x10-7 and 2.0x10-6 mol L-1 with a limit of detection of 5x10-8 mol L-1 for an accumulation time of 30 s. The precision of the method was evaluated by assessing the repeatability and intermediate precision, achieving good relative standard deviations in all cases (≤2.3%). The proposed method was applied to the determination of citalopram in five pharmaceutical products and the results obtained are in good agreement with the labeled values.
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Aiming the establishment of simple and accurate readings of citric acid (CA) in complex samples, citrate (CIT) selective electrodes with tubular configuration and polymeric membranes plus a quaternary ammonium ion exchanger were constructed. Several selective membranes were prepared for this purpose, having distinct mediator solvents (with quite different polarities) and, in some cases, p-tert-octylphenol (TOP) as additive. The latter was used regarding a possible increase in selectivity. The general working characteristics of all prepared electrodes were evaluated in a low dispersion flow injection analysis (FIA) manifold by injecting 500µl of citrate standard solutions into an ionic strength (IS) adjuster carrier (10−2 mol l−1) flowing at 3ml min−1. Good potentiometric response, with an average slope and a repeatability of 61.9mV per decade and ±0.8%, respectively, resulted from selective membranes comprising additive and bis(2-ethylhexyl)sebacate (bEHS) as mediator solvent. The same membranes conducted as well to the best selectivity characteristics, assessed by the separated solutions method and for several chemical species, such as chloride, nitrate, ascorbate, glucose, fructose and sucrose. Pharmaceutical preparations, soft drinks and beers were analyzed under conditions that enabled simultaneous pH and ionic strength adjustment (pH = 3.2; ionic strength = 10−2 mol l−1), and the attained results agreed well with the used reference method (relative error < 4%). The above experimental conditions promoted a significant increase in sensitivity of the potentiometric response, with a supra-Nernstian slope of 80.2mV per decade, and allowed the analysis of about 90 samples per hour, with a relative standard deviation <1.0%.
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The present work describes the development of an analytical method for the determination of methiocarb and its degradation products (methiocarb sulfoxide and methiocarb sulfone) in banana samples, using the QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure followed by liquid chromatography coupled to photodiode array detector (LCPAD). Calibration curves were linear in the range of 0.5−10 mg L−1 for all compounds studied. The average recoveries, measured at 0.1 mg kg−1 wet weight, were 92.0 (RSD = 1.8%, n = 3), 84.0 (RSD = 3.9%, n = 3), and 95.2% (RSD = 1.9%, n = 3) for methiocarb sulfoxide, methiocarb sulfone, and methiocarb, respectively. Banana samples treated with methiocarb were collected from an experimental field. The developed method was applied to the analysis of 24 samples (peel and pulp) and to 5 banana pulp samples. Generally, the highest levels were found for methiocarb sulfoxide and methiocarb. Methiocarb sulfone levels were below the limit of quantification, except in one sample (not detected).
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Cost-effective glass-reinforced thermoplastic matri x towpregs produced by a powder coating line were used to manufacture composite pipes by fi lament winding. A conventional 6 axes filament-winding equipment was adapted for processi ng such structures. The influence of the filament winding speed and mandrel temperature on t he composite final properties was studied in the present work. An optimized processin g window was established by comparing the composite theoretical expected mechanical prope rties with the experimentally obtained ones. The final properties determined on the produc ed pipes and structures and the technological changes introduced to the conventiona l filament-winding equipment will be presented and discussed. Besides the processing des cription and conditions, it will be presented the relationship between processing condi tions and mechanical properties.
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Pultruded products are being targeted by a growing demand due to its excellent mechanical properties and low chemical reactivity, ensuring a low level of maintenance operations and allowing an easier assembly operation process than equivalent steel bars. In order to improve the mechanical drawing process and solve some acoustic and thermal insulation problems, pultruded pipes of glass fibre reinforced plastics (GFRF) can be filled with special products that increase their performance regarding the issues previously referred. The great challenge of this work was drawing a new equipment able to produce pultruded pipes filled with cork or polymeric pre-shaped bars as a continuous process. The project was carried out successfully and the new equipment was built and integrated in the pultrusion equipment already existing, allowing to obtain news products with higher added-value in the market, covering some needs previously identified in the field of civil construction.
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The World Business Council for Sustainable Development (WBCSD) defines Eco-Efficiency as follows: ‘Eco- Efficiency is achieved by the delivery of competitively priced-goods and services that satisfy human needs and bring quality of life, while progressively reducing ecological impacts and resource intensity throughout the life-cycle to a level at least in line with the earth’s estimated carrying capacity’. Eco-Efficiency is under this point of view a key concept for sustainable development, bringing together economic and ecological progress. Measuring the Eco-Efficiency of a company, factory or business, is a complex process that involves the measurement and control of several and relevant parameters or indicators, globally applied to all companies in general, or specific according to the nature and specificities of the business itself. In this study, an attempt was made in order to measure and evaluate the eco-efficiency of a pultruded composite processing company. For this purpose the recommendations of WBCSD [1] and the directives of ISO 14301 standard [2] were followed and applied. The analysis was restricted to the main business branch of the company: the production and sale of standard GFRP pultrusion profiles. The main general indicators of eco-efficiency, as well as the specific indicators, were defined and determined according to ISO 14031 recommendations. With basis on indicators’ figures, the value profile, the environmental profile, and the pertinent eco-efficiency’s ratios were established and analyzed. In order to evaluate potential improvements on company eco-performance, new indicators values and ecoefficiency ratios were estimated taking into account the implementation of new proceedings and procedures, both in upstream and downstream of the production process, namely: a) Adoption of new heating system for pultrusion die in the manufacturing process, more effective and with minor heat losses; b) Implementation of new software for stock management (raw materials and final products) that minimize production failures and delivery delays to final consumer; c) Recycling approach, with partial waste reuse of scrap material derived from manufacturing, cutting and assembly processes of GFRP profiles. In particular, the last approach seems to significantly improve the eco-efficient performance of the company. Currently, by-products and wastes generated in the manufacturing process of GFRP profiles are landfilled, with supplementary added costs to this company traduced by transport of scrap, landfill taxes and required test analysis to waste materials. However, mechanical recycling of GFRP waste materials, with reduction to powdered and fibrous particulates, constitutes a recycling process that can be easily attained on heavy-duty cutting mills. The posterior reuse of obtained recyclates, either into a close-looping process, as filler replacement of resin matrix of GFRP profiles, or as reinforcement of other composite materials produced by the company, will drive to both costs reduction in raw materials and landfill process, and minimization of waste landfill. These features lead to significant improvements on the sequent assessed eco-efficiency ratios of the present case study, yielding to a more sustainable product and manufacturing process of pultruded GFRP profiles.
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Dissertação de Mestrado Mestrado em Empreendedorismo e Internacionalização Orientada por Mestre Anabela Ribeiro
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Dissertação de Mestrado apresentada ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Marketing Digital, sob orientação do Professor Doutor José de Freitas Santos