1,624 research outputs found

    Development and application of a laminar coflow burner for combustion studies at high pressure

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    In the present thesis, it is attempted to build a bridge between the most simplified systems that have already been studied in literature (laminar flame burners, in which simple fuels such as methane, ethane or ethylene are burnt at atmospheric pressure) and the much more complex and demanding environment that is found in practical combustion engines. This is accomplished by designing and constructing a high pressure vessel and laminar burner (HPVB) integrated with an evaporation system. The capability of the HPVB setup of burning vaporized liquid fuels in laminar diffusion and partially premixed flames brings the important opportunity to isolate more easily the impact of fuel chemistry on the combustion behavior of relevant fuels and biofuels. This experimental setup is particularly designed to offer optical accessibility for laser diagnostic techniques, also allowing their assessment and development at elevated pressures. Background information on the type of burners mostly used for combustion studies in laminar flames is given in chapter 2 with focus on measurements in a high pressure environment. A detailed description of the design capabilities of the HPVB setup and the flame stability issues encountered are also presented and discussed. The theory behind the laser diagnostic techniques applied in this work are reviewed in chapter 3. The chapters 4 to 6 present the measurements carried out to characterize a large range of flames from gaseous and vaporized liquid fuels using laser diagnostics. In chapter 7, the heat flux method for laminar burning velocity measurements is presented and a feasibility study is performed to extend the applicability of the method to higher pressures. This is accomplished by integrating the heat flux burner in the high pressure vessel of the HPVB setup. Chapter 8 summarizes the conclusions and provide recommendations

    Immune response and performance of growing Santa Ines lambs to artificial Trichostrongylus colubriformis infections

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    AbstractThis study was carried out to evaluate the immune response and the impact of Trichostrongylus colubriformis infections on the performance of growing Santa Ines lambs. Thirty male lambs, 3–4 months of age, were maintained in individual pens and restrictively randomised by weight into 3 treatment groups: (1) infected group, artificially infected with 2500 T. colubriformis larvae, three times a week, for 13 weeks, and fed ad libitum; (2) Pair-Fed Group, non-infected and fed with the same amount of food consumed by the infected animal of the same class on the previous day; and (3) control group, non-infected and fed ad libitum. Refused feed was weighed daily to assess the food intake of each lamb. Animals were weighed weekly and blood and fecal samples were collected. At the end of the trial, all lambs were euthanized to determine worm burden and collect intestinal tissues and mucus samples for histological and immunological analysis. The infected group presented eosinophilia, increased number of inflammatory cells in the mucosa, in addition to an increased production of specific immunoglobulins against T. colubriformis, which partially prevented the establishment of infective larvae. As a consequence of parasitism, the infected lambs presented reduced serum albumin concentrations and demonstrated severe small intestine lesions, such as villous atrophy and epithelial erosion, which impaired the digestion and absorption of nutrients, causing a significant loss in performance. The infected group presented a 37% reduction in daily weight gain (107.26±10.8g/day), when compared with the control group (171.07±7.15g/day). The infected lambs also demonstrated the worst food conversion, i.e., each animal needed to consume on average 10.05±0.52kg of food to gain 1kg live weight. The voluntary hay intake depression in infected animals was small, and statistical difference (P<0.01) was seen only on two occasions (ninth and 12th weeks), in comparison with the control group. In conclusion, Santa Ines lambs infected with T. colubriformis demonstrated a reduction in performance, caused by the damages produced by the adult nematodes in intestinal mucosa, and also by the immunopathological changes associated with the infection

    Naturally occurring ingredients as potential antiaging cosmetics

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    The criteria adopted for establishing whether a determined substance has potential as a cosmetic constituent are based on the present legislation of each country. In this study, natural antiaging constituents as Fomes officinalis, rice protein and glutamic acid were pharmacologically evaluated using neuromuscular preparation. These constituents induced a neuromuscular blockade, individually and also in mixture, simulating a Botox®, but not, dimethylaminoethanol-effect. The pharmacological knowledge is beneficial since the real effect of each ingredient becomes apparent, increasing the consumer's confidence on the antiaging cosmetic.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Naturally occurring ingredients as potential antiaging cosmetics

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    The criteria adopted for establishing whether a determined substance has potential as a cosmetic constituent are based on the present legislation of each country. In this study, natural antiaging constituents as Fomes officinalis, rice protein and glutamic acid were pharmacologically evaluated using neuromuscular preparation. These constituents induced a neuromuscular blockade, individually and also in mixture, simulating a Botox®, but not, dimethylaminoethanol-effect. The pharmacological knowledge is beneficial since the real effect of each ingredient becomes apparent, increasing the consumer's confidence on the antiaging cosmetic.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Avaliação do impacte de fogos florestais em recursos hídricos subterrâneos

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    Comunicação apresentada no Seminário sobre Águas Subterrâneas, organizado pela Associação Portuguesa de Recursos Hídricos, que decorreu de 1 a 2 de Março de 2007 em Lisboa.Apresentam-se os objectivos, as tarefas e os primeiros resultados obtidos do Projecto actualmente em curso “Avaliação do impacte de fogos florestais nos recursos hídricos subterrâneos” (POCI/AGR/59180/2004). Os objectivos principais deste Projecto são estudar o impacte dos fogos nas quantidades de água envolvidas nos diversos processos do ciclo hidrológico e estudar o impacte das substâncias poluentes existentes nas cinzas florestais, no solo e no meio hídrico subterrâneo. Criou-se uma rede de monitorização da piezometria e da qualidade da água, e seleccionaram-se pontos de amostragem de solos e de cinzas em quatro áreas ardidas e não ardidas no concelho de Mação, para caracterizar e avaliar a influência que os fogos florestais têm na potencial degradação das Associação Portuguesa dos Recursos Hídricos 2 águas de superfície e subterrâneas. As áreas seleccionadas foram: bacia do Caratão, bacia do Carvoeiro, Bacia da Quebrada e Penhascoso. Para estas áreas estuda-se o coberto vegetal, os solos, a hidrogeologia, o clima e as condições de escoamento. Tem sido feita a monitorização dos níveis de água em furos e poços, assim como a amostragem de água para análise físico-química dos iões maiores e dos hidrocarbonetos aromáticos policíclicos (HAP). Para os solos, cinzas e lixiviados são analisados os seguintes elementos: Al, Ca, Fe, K, Na, Mg, Cd, Cu, Cr, Mn, Ni, Pb, Zn, Hg, S, C, H, N, e HAP. Para as bacias do Caratão e do Carvoeiro foi feito o inventário fitosociológico, comportando os aspectos fisiográficos, de geologia, de hidrologia e de vegetação (considerando 23 espécies), tendo-se desenvolvido a análise estatística dos dados, e foi feita a caracterização pedológica quanto aos parâmetros pH, matéria orgânica, P e K. Nas mesmas bacias foi feita a recolha de material vegetal para incineração em instalação de combustão, existindo já resultados analíticos para cinzas de arbustos e respectivos lixiviados

    Constraining Warm Inflation with the Cosmic Microwave Background

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    We discuss the spectrum of scalar density perturbations from warm inflation when the friction coefficient Γ\Gamma in the inflaton equation is dependent on the inflaton field. The spectral index of scalar fluctuations depends on a new slow-roll parameter constructed from Γ\Gamma. A numerical integration of the perturbation equations is performed for a model of warm inflation and gives a good fit to the WMAP data for reasonable values of the model's parameters.Comment: 6 pages, 2 figures, RevTeX

    Salvado de harina y salvado de fécula de mandioca como potenciales excipientes para comprimidos

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    Acknowledgements: Fundação Dom Aguirre, for finantial support to Valéria Campos Orsi. Project funding by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, São Paulo, Brazil) (FAPESP Ref. No. 2018/05522-9 (Project PsaPhageKill)) in the form of a BPE fellowship granted to Victor M. Balcão is hereby gratefully acknowledged. This work also received support from CNPq, National Council for Scientific and Technological Development Brazil, in the form of Research Productivity (PQ) fellowships granted to Victor M. Balcão (Refs. No. 306113/2014-7 and 308208/2017-0).Objectives: The physicochemical characteristics of bran of cassava starch flour and bran of cassava flour (viz. organoleptic characteristics, pH value, moisture content, total ashes, lipid, protein, starch and fiber contents) and biopharmacotechnical parameters (viz. granulometry, flow capacity, angle at rest, outflow time and apparent density) were evaluated aiming at assessing their potential use as tablet excipients. Methodos: Three tablet formulations of venlafaxine hydrochloride were proposed, having as excipients bran of cassava flour, bran of cassava starch flour and Starch 1500®. The tablets were produced using two different pressures (98±5 MPa and 32±6 Mpa) and their mechanical (hardness and friability) and dissolubility characteristics were evaluated. Results and Conclusions: The tablets produced with both cassava flours, using higher pressures, presented similar physicochemical characteristics to those obtained with the excipient Starch1500®, thus indicating that cassava flours possess the potential to be used as disintegrating agents in tablets.Objetivos: Se evaluaron características físico-químicas del salvado de harina y del salvado de la fécula de mandioca (características organolépticas, pH, humedad, cenizas totales y contenido de lípidos, proteínas, almidones y fibras) y biofarmacotécnicas (granulometría, capacidad de flujo, ángulo en reposo, tiempo de salida y densidad aparente) con el objetivo de evaluar el uso de estos residuos como excipientes para comprimidos. Métodos: Se propusieron tres formulaciones en comprimidos de venlafaxina teniendo como excipientes salvado de harina de mandioca, salvado de fécula de mandioca y Starch 1500 ®. Las pastillas se produjeron utilizando dos presiones diferentes (98 ± 5 MPa y 32 ± 6 Mpa). Las características mecánicas (dureza y friabilidad) y de disolución de los comprimidos se evaluaron. Resultados y Conclusiones: Los comprimidos producidos con ambos salvados de mandioca, utilizando las presiones más elevadas, presentaron características físico-químicas similares a las obtenidas con el excipiente Starch1500®, indicando que las harinas de mandioca poseen potencial para ser utilizadas como agentes desintegrantes en comprimidos

    Desenvolvimento de uma metodologia para avaliação de impactos qualitativos dos fogos nas águas subterrâneas : aplicação aos casos de estudo do Vale de Manteigas e de Mação

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    No Projecto POCI/AGR/59180/2004, concluído em 2009 (cf. Lobo-Ferreira et al., 2009), apresenta-se uma metodologia para avaliação quantitativa dos impactos dos fogos florestais na quantidade e qualidade das águas superficiais e subterrâneas. Nesta metodologia procura-se avaliar as alterações que possam ter ocorrido após o fogo: (A) em volumes de recarga, (B) volumes de escoamento superficial, (C) qualidade das águas superficiais e subterrâneas. Esta metodologia considera: (1) tipo e densidade de coberto vegetal à data do incêndio; (2) tipos de poluentes que podem ser libertados pelas diferentes comunidades vegetais afectadas pelo fogo; (3) extensão e volume do aquífero e sua porosidade eficaz, para aferir dos volumes de reservas de água; (4) recarga média anual; (5) tempo de permanência das águas no sistema subterrâneo. Para a avaliação do tipo e densidade de coberto vegetal e consequente biomassa combustível à data do incêndio usou-se a inventariação fitossociológica, cartografia da vegetação, análise estatística multivariada e estimativa da biomassa florestal ardida, realizada pelo Instituto Politécnico de Castelo Branco-Escola Superior Agrária. Os tipos e cargas poluentes libertados calcularam-se com base nos valores de biomassa ardida e estudos (realizados por INETI – Departamento de Engenharia Energética e Controlo Ambiental) de cinzas de ensaios de combustão de espécies florestais e arbustivas representativas do coberto vegetal ardido, e ensaios de lixiviação de solos e cinzas. A avaliação das variações na recarga baseou-se na informação recolhida nos estudos quantitativos realizados na bacia de Manteigas, associada a modelos hidrológicos conceptuais e cenários de variação de escoamento e evapotranspiração quando a informação não era suficiente para colmatar as lacunas de conhecimento. Com base na biomassa ardida, características composicionais das suas cinzas e potenciais de lixiviação, calculou-se a quantidade e tipo de poluentes em fase sólida e dissolvida passíveis de entrar nas águas superficiais e subterrânea. As características hidráulicas dos meios geológicos afectados deram os volumes de armazenamento e as prováveis velocidades de circulação nestes materiais, o que serviu para prever espaços temporais de contaminação da área. Da avaliação dos volumes de carga poluente calculados e dos dados de campo de decaimento destas cargas poluentes nas águas superficiais e subterrâneas em zonas de coberto vegetal similar estabeleceram-se cenários possíveis do tempo de desaparição do poluente na área ardida. Nesta comunicação realçam-se os aspectos relacionados com a qualidade das águas subterrâneas

    Grondwet van de republiek Nederland

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