997 resultados para Fibras Alimentares


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Os padrões baixos de Actividade Física (AF), com aumento de tempo em actividades sedentárias (ActSed), num envolvimento natural (EnvN) desafiador e um elevado consumo de alimentos processados (AliPro) e de bebidas açucaradas (BeAçu), são factores responsáveis pelo aumento da obesidade nos jovens. Este trabalho tem por objectivo caracterizar os alunos do 7º ano de escolaridade, de duas escolas: Região Autónoma da Madeira (R.A.M.) e outra nos Açores (R.A.A.), bem como estudar as relações entre as variáveis AFg, ActSed, EnvN, o consumo dos AliPro e de BeAçu, e os indicadores de adiposidade. O total da amostra consistiu em 337 alunos (164 rapazes e 173 raparigas), sendo 123 da escola da R.A.A. e 214 da escola da R.A.M., ambas de um meio medianamente urbano. Os participantes preencheram questionários acerca da AF (Crocker, Bailey, Faulkner, Kowalski & McGrath, 1997), percepção de envolvimento físico (Evenson et al., 2006), ActSed e consumo alimentar (Wilson, Magarey & Mastersson, 2008). Foi efectuada a avaliação ao nível do peso, altura e pregas de adiposidade tricipital e geminal (Cooper, 2007). A %MG foi calculada segundo a fórmula de Slaughter et al.(1988) e os participantes classificados segundo as categorias de Lohman (1987). Os alunos reportaram resultados baixos nos níveis de AF, e em média um dispêndio de 3 horas por dia em ActSed. Cada participante afirma consumir aproximadamente 3 AliPro e 1 BeAçu por dia. No parâmetro da %MG, os resultados de ambas as escolas foram considerados alarmantes. Foram encontradas diferenças não significativas, entre as duas escolas, nos parâmetros de AF, ActSed, consumo de AliPro e BeAçu, EnvN e %MG (p> 0,05). Correlações moderadas entre as ActSed e o consumo de BeAçu; e fracas entre o EnvN, BeAçu e AliPro, e AliPro com o IMC e %MG. Em suma, ocorrem necessidades de hábitos de AF para a prevenção da obesidade.

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O presente trabalho teve como objectivo caracterizar a população escolar do 5.º ao 12º anos de escolaridade do concelho de Santana, relativamente aos níveis de adiposidade, de aptidão e actividade física, actividades sedentárias e hábitos alimentares. A amostra foi constituída por 505 jovens de ambos os géneros, com idades compreendidas entre os 10 e os 22 anos, distribuídos por quatro grupos etários. A composição corporal foi caracterizada através de: 1) do IMC, com base nos valores de referência de Cole et al. (2000), para determinar excesso de peso e obesidade, e de Cole et al. (2007), para a subnutrição; 2) cálculo da %MG através das pregas subcutâneas segundo as fórmulas de Slaughter et al. (1988), e classificada segundo Lohman (1987). A aptidão física foi avaliada segundo as orientações da bateria de testes Fitnessgram (Cooper Institute for Aerobics Research, 2002). As actividades sedentárias e os hábitos alimentares foram avaliados através de questionários (Sallis et al., 1999 e Wilson et al., 2008 respectivamente), e o grupo de participação desportiva, determinado a partir de questões relativas à prática de actividades desportivas organizadas. Os resultados demonstram uma taxa de prevalência de excesso de peso e obesidade de 26,7%, sendo superior a taxa de prevalência nos participantes do sexo masculino e de idade mais baixa. Ao nível da actividade física organizada extracurricular, verificou-se que 41,5% indicaram praticar outra actividade (DE ou DF), para além das aulas de EF. Relativamente a aptidão física, constatamos que metade da população avaliada, foi classificada abaixo da Zona Saudável de Aptidão Física (ZSAptF), em pelo menos 3, dos 6 testes motores avaliados. A aptidão aeróbia revelou-se como uma das componentes da aptidão com maior taxa de insucesso (54,8%). Ainda na aptidão, verificamos que os participantes classificados abaixo ZSAptF na componente aptidão aeróbia diferiam dos classificados dentro da ZSAptF, nos parâmetros: a) obesidade; b) restantes testes motores da aptidão física avaliados; c) actividades sedentárias (navegar da net; jogo de vídeo portáteis); d) participação desportiva; e) frequência de consumo de bebidas açucaradas, sendo que em média, os alunos classificados abaixo da ZSAptF, apresentam valores superiores de obesidade, piores prestações nos testes motores, menor probabilidade de participarem em actividades organizadas extracurriculares e menor consumo de bebidas açucaradas.

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ANDRADE JR., T. E. et al. Infiltração de sal de alumínio em fibras de sisal para obtenção de fibras de alumina. Cerâmica, v.51, n.317, p.37-41.ISSN 0366-6913. Disponível em:. Acesso em: 06 out. 2010.

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The evaluation of public policies that promote Food Security and Nutrition (FSN) it s a multidisciplinary activity extremely relevant to the effectiveness of actions to legitimize the Human Right to Adequate Food (HRAF). This study aimed at assessing the effectiveness of the unit project Natal-RN Café do Trabalhador in promoting SAN to its users. The theoretical framework is based on the public and political and on the dimensions of the concept of FSN (quantity and quality-regularity). Through a qualitative approach, methodologically this was the work of an evaluation of efficiency of the unit Natal-RN of Café do Trabalhador project in light of the assumptions of the concept of SAN. Data collection was conducted through retrospective archival research in official documents of the project, semi-structured interviews with managers involved in its implementation (representative of the Secretary of State for Employment, Housing and Care of RN SETHAS and third party), socioeconomic questionnaire applied to the users of the unit, check the amount, regularity and quality of meals offered for 15 days (menu routine) using the descriptive form menu and form filling type checklist for verification of compliance with good practices . Methods of analysis, we used content analysis, descriptive statistics and compared to previously established parameters for the project. As categories of analysis were defined organizational arrangement, access, user, food quantity-regularity and food quality. The results show that, it was found in the category arrangement that will implement the project dismissed technical criteria for choosing the districts and the quantitative distribution of meals for each location. It was found that the valuation of the shares of the company outsources technical SETHA has not been performed. We observed in the access category, the unit has a strategic location, but lack of space in the refectory. The main obstacle to economic access for users is the lack of a register for the beneficiaries. In the category of users, it was identified that the clientele of the project it is predominantly men, with more than 51 years, low education, earning wages less 1 obtained through informal employment, which they move up through the unit transport collective, go to all days of operation due primarily to price. About the meals category quantity-regularity of food showed that the menu serves 95% of the desired needs, and that holidays and weekends are periods of disrupting the regularity of supply of meals. Regarding the category of food quality, it was found that the nutritional aspect on the menu are food sources rich in sodium, nitrates and low in fiber. In the aspect of hygiene and sanitation are the main limitations related to waste management, lack of exposure controls of food prepared and inadequacies of the physical structure. The results showed that in general and the institutional arrangement of the organs attached to the project should establish a systematic evaluation project is to establish as a promoter of and FSN overcome these obstacles

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The use of raw materials from renewable sources for production of materials has been the subject of several studies and researches, because of its potential to substitute petrochemical-based materials. The addition of natural fibers to polymers represents an alternative in the partial or total replacement of glass fibers in composites. In this work, carnauba leaf fibers were used in the production of biodegradable composites with polyhydroxybutyrate (PHB) matrix. To improve the interfacial properties fiber / matrix were studied four chemical treatments to the fibers..The effect of the different chemical treatments on the morphological, physical, chemical and mechanical properties of the fibers and composites were investigated by scanning electron microscopy (SEM), infrared spectroscopy, X-ray diffraction, tensile and flexural tests, dynamic mechanical analysis (DMA), thermogravimetry (TGA) and diferential scanning calorimetry (DSC). The results of tensile tests indicated an increase in tensile strength of the composites after the chemical treatment of the fibers, with best results for the hydrogen peroxide treated fibers, even though the tensile strength of fibers was slightly reduced. This suggests a better interaction fiber/matrix which was also observed by SEM fractographs. The glass transition temperature (Tg) was reduced for all composites compared to the pure polymer which can be attributed to the absorption of solvents, moisture and other low molecular weight molecules by the fibers

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Sisal is a renewable agricultural resource adapted to the hostile climatic and soil conditions particularly encountered in the semi-arid areas of the state of Rio Grande do Norte. Consequently, sisal has played a strategic role in the economy of the region, as one of few options of income available in the semi-arid. Find new options and adding value to products manufactured from sisal are goals that contribute not only to the scientific and technological development of the Northeastern region, but also to the increase of the family income for people that live in the semi-arid areas where sisal is grown. Lignocellulosic fibers are extracted from sisal and commonly used to produce both handcrafted and industrial goods including ropes, mats and carpets. Alternatively, addedvalue products can be made using sisal to produce alumina fibers (Al2O3) by biotemplating, which consists in the reproduction of the natural fiber-like structure of the starting material. The objective of this study was to evaluate the conditions necessary to convert sisal into alumina fibers by biotemplating. Alumina fibers were obtaining after pretreating sisal fibers and infiltrating them with a Al2Cl6 saturated solution, alumina sol from aluminum isopropoxide or aluminum gas. Heat-treating temperatures varied from 1200 ºC to 1650 °C. The resulting fibers were then characterized by X-ray diffraction and scanning electronic microscopy. Fibers obtained by liquid infiltration revealed conversion only of the surface of the fiber into α-Al2O3, which yielded limited resistance to handling. Gas infiltration resulted in stronger fibers with better reproduction of the inner structure of the original fiber. All converted fibers consisted of 100% α-Al2O3 suggesting a wide range of technological applications especially those that require thermal isolation

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The gradual replacement of conventional materials by the ones called composite materials is becoming a concern about the response of these composites against adverse environmental conditions, such as ultraviolet radiation, high temperature and moist. Also the search for new composite using natural fibers or a blend of it with synthetic fibers as reinforcement has been studied. In this sense, this research begins with a thorough study of microstructural characterization of licuri fiber, as a proposal of alternative reinforcement to polymeric composites. Thus, a study about the development of two composite laminates was done. The first one, involving only the fiber of licuri and the second comprising a hybrid composite based of fiber glass E and the fiber of licuri, in order to know the performance of the fiber when of fiber across the hybridization process. The laminates were made in the form of plates using the tereftálica ortho-polyester resin as matrix. The composite laminate made only by licuri fiber had two reinforcing fabric layers of unidirectional licuri and the hybrid composite had two reinforcing layers of unidirectional licuri fabric and three layers of fiber short glass-E mat. Finally, both laminates was exposed to aging acceleration in order to study the influence of environmental degradation involving the mechanical properties and fracture characteristics thereof. Regarding the mechanical properties of composites, these were determined through uniaxial tensile tests, uniaxial compression and three bending points for both laminates in original state, and uniaxial tensile tests and three bending points after accelerated aging. As regards the study of structural degradation due to aging of the laminates, it was carried out based on microscopic analysis and microstructure, as well as measuring weight loss. The characteristics of the fracture was performed by macroscopic and microscopic (optical and SEM) analysis. In general, the laminated composites based on fiber licuri showed some advantages in their responses to environmental aging. These advantages are observed in the behavior related to stiffness as well as the microstructural degradation and photo-oxidation processes. However, the structural integrity of this laminate was more affected in case the action of uniaxial tensile loads, where it was noted a lower rate of withholding his last resistance property

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The use of gypsum, one of the oldest building materials for the construction industry in the country has been experiencing a significant and steady growth, due to its low cost and some of its properties that confer comparative advantage over other binder materials. Its use comprises various applications including the coating of walls and the production of internal seals and linings. Moreover, the fibers are being increasingly incorporated into arrays fragile in an attempt to improve the properties of the composite by reducing the number of cracks, the opening of the same and its propagation velocity. Other properties, depending on the function of the component material or construction, among these thermal and acoustic performances, are of great importance in the context of buildings and could be improved, that is, having better performance with this embodiment. Conduct a comparative study of physico-mechanical, thermal and acoustic composite gypsum incorporating dry coconut fiber, in the form of blanket, constituted the main objective of this work. Improving the thermal and acoustic performances of precast gypsum, used for lining and internal vertical fences of buildings, was the purpose of development of these composites. To evaluate the effect of fiber content on the properties of the composites were used to manufacture the composite layer with different thicknesses. The composites were fabricated in the form of plates with dimensions of 500x500x24mm. To facilitate the comparative study of the properties were also made with material gypsum boards only. We then determined the physico-mechanical, thermal and acoustical plaster and composites. The results indicated that the composites were significant gains in relation to thermal performance and also acoustic, in certain frequency range, increasing the thickness of the blanket. Concerning other physical-mechanical properties, the results showed that although the compressive strength was lower than for the composite did not occur after a fracture catastrophic failure. The same trend was observed with regard to resistance to bending, since the composites have not suffered sudden rupture and still continued after the load supporting point of maximum load

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This research was motivated by the requirement of asbestos s replacement in building systems and the need to generate jobs and income in the country side of the state of Bahia, Brazil. The project aimed at using fibers from licuri leaves (syagrus coronata), an abundant palm in the region, to produce composites appropriate for the sustainable production of cement fibre reinforced products in small plants. The composites were produced in laboratory using Portland cement CP-II-F32, sand, water, licuri palm fiber contents of 1.0, 1.5 and 2.0% by weight of binder (two different fiber length) and metakaolin. The latter was chosen as an additional binder for its efficiency to reduce the alkalinity of cementitious matrixes therefore preventing the degradation of vegetable fibers. The characterization of the composite components was carried out by sieving and laser particle size analyses, thermal analysis, fluorescence and X-ray diffraction. The composites performance was evaluated by 3- point-bending tests, compressive strength, ultrasound module of elasticity, free and restrained shrinkage, water capillarity absorption and apparent specific gravity. It has been found that the addition of fibers increased the time to onset of cracking over 200.00% and a 25% reduction in cracks opening in the restrained shrinkage test. The capillary absorption reduced about 25% when compared to fiber-free composites. It was also observed with regard to flexural strength, compressive strength and specific gravity, that the addiction of fibers did not affect the composite performance presenting similar results for compounds with and without fibers. In general it can be stated that the reinforced composite fibers of palm licuri presents physical and mechanical characteristics which enable them to be used in the intended proposals of this research