3,749 research outputs found

    Melhoramento de espécies aquícolas com foco na resistência a doenças.

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    Introdução. Aspectos a serem considerados no melhoramento genético com foco em doenças. Estimativas de herdabilidade e de correlações genéticas entre resistência a doenças e outras características. Cuidados no desenho experimental dos desafios para a fenotipagem de animais. Considerações finais. Referências.bitstream/item/136151/1/CNPASA2015doc17.pd

    Modeling electrodialysis and a photochemical process for their integration in saline wastewater treatment.

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    Oxidation processes can be used to treat industrial wastewater containing non-biodegradable organic compounds. However, the presence of dissolved salts may inhibit or retard the treatment process. In this study, wastewater desalination by electrodialysis (ED) associated with an advanced oxidation process (photo-Fenton) was applied to an aqueous NaCl solution containing phenol. The influence of process variables on the demineralization factor was investigated for ED in pilot scale and a correlation was obtained between the phenol, salt and water fluxes with the driving force. The oxidation process was investigated in a laboratory batch reactor and a model based on artificial neural networks was developed by fitting the experimental data describing the reaction rate as a function of the input variables. With the experimental parameters of both processes, a dynamic model was developed for ED and a continuous model, using a plug flow reactor approach, for the oxidation process. Finally, the hybrid model simulation could validate different scenarios of the integrated system and can be used for process optimization

    Researches is health of Pirarucu, Arapaima gigas: partnership between EMBRAPA-SEBRAE.

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    Aiming to deepen the scientific knowledge on health aspects of pirarucu, and attempting to improve the fingerlings survival rates a partnership was signed between SEBRAE and EMBRAPA, in collaboration with the UFT

    Reactive power management of a wind farm to prevent voltage collapse of an electric power system

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    Nowadays, the large penetration of wind power generation poses new challenges for dynamic voltage stability analysis of an electric power system. The practical importance of dynamic voltage stability analysis is to help in designing and selecting counter-measures in order to avoid voltage collapse and enhance system stability. The impact of wind integration on reactive reserve requirements is a current area of interest for renewable integration studies and power system operators. In this paper is studied a new wind power plant model with reactive power management. The active power and the frequency management are taken into account too. The developed model can be used to represent, in a simplified way, an entire wind farm in order to simulate the dynamic voltage stability of the system, whatever the technology involved in the wind turbine. The system is completely modelled by a single dynamic converter model with appropriate control loops intended to reproduce the overall response of a wind farm for different grid events, such as faults or voltage and reactive power management at the point of common coupling. Â(c) 2015 IEEE

    Planetary Nebula Abundances and Morphology: Probing the Chemical Evolution of the Milky Way

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    This paper presents a homogeneous study of abundances in a sample of 79 northern galactic planetary nebulae whose morphological classes have been uniformly determined. Ionic abundances and plasma diagnostics were derived from selected optical line strengths in the literature, and elemental abundances were estimated with the Ionization Correction Factor developed by Kingsbourgh & Barlow (1994). We compare the elemental abundances to the final yields obtained from stellar evolution models of low-and intermediate-mass stars, and we confirm that most Bipolar planetary nebulae have high nitrogen and helium abundance, and are the likely progeny of stars with main-sequence mass larger than 3 solar masses. We derive =0.27, and discuss the implication of such a high ratio in connection with the solar neon abundance. We determine the galactic gradients of oxygen and neon, and found Delta log (O/H)/Delta R=-0.01 dex/kpc$ and Delta log (Ne/H)/Delta R=-0.01 dex/kpc. These flat PN gradients do not reconcile with galactic metallicity gradients flattening with time.Comment: The Astrophysical Journal, in pres

    Sulfur, Chlorine, & Argon Abundances in Planetary Nebulae. I: Observations and Abundances in a Northern Sample

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    This paper is the first of a series specifically studying the abundances of sulfur, chlorine, and argon in Type II planetary nebulae (PNe) in the Galactic disk. Ratios of S/O, Cl/O, and Ar/O constitute important tests of differential nucleosynthesis of these elements and serve as strict constraints on massive star yield predictions. We present new ground-based optical spectra extending from 3600-9600 Angstroms for a sample of 19 Type II northern PNe. This range includes the strong near infrared lines of [S III] 9069,9532, which allows us to test extensively their effectiveness as sulfur abundance indicators. We also introduce a new, model-tested ionization correction factor for sulfur. For the present sample, we find average values of S/O=1.2E-2(+/- 0.71E-2), Cl/O=3.3E-4(+/- 1.6E-4), and Ar/O=5.0E-3(+/- 1.9E-3).Comment: 44 pages, 6 figures. Accepted for publication in the Astrophysical Journa

    Alternative Intelligent Material for Packaging Using Chitosan Films as Colorimetric Temperature Indicators

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    Chlorophyll was incorporated into chitosan films, forming intelligent systems able to detect variations in temperature. Chitosan is a biodegradable polymer that forms flexible, resistant films with an efficient oxygen barrier. Chlorophyll was added (0.25 g/100 g) into chitosan suspension (2.00 g/100 g) and intelligent films (FIQ) were cast. the effects of temperature (10 degrees C to 50 degrees C) and luminosity (0 to 1000 lx) on the films were studied using an experimental design with two variables, analyzing the color parameters L*, a*, b* and mechanical properties. the films were characterized according to their homogeneity, flexibility, color and handling. Chitosan suspensions containing chlorophyll were also applied as coating on the surface of pieces of card-paper, forming a card paper film system (S-FP). By visual inspection we observed the color of the S-FP changing irreversibly from green to yellow when the temperature was above 50 degrees C. Therefore, the S-FP system can potentially be used as a colorimetric indicator for the 50 degrees C to 70 degrees C range, being advantageous owing to the ease of fabrication, biodegradability, safe use for food and low cost.Clorofila, um pigmento natural termossensível, foi incorporado à matriz de filmes de quitosana visando a obter sistemas inteligentes de indicação de variação de temperatura. A quitosana é um polímero biodegradável que forma filmes flexíveis com eficiente barreira ao oxigênio, podendo ser alternativa ao uso de polímeros sintéticos. Clorofila foi adicionada (0,25 g/100 g) à suspensão de quitosana (2,00 g/100 g) formando filmes inteligentes de quitosana (FIQ). Os efeitos da temperatura (10 °C a 50 °C) e luminosidade (0 a 1000 lx) foram estudados utilizando um planejamento experimental, avaliando os parâmetros de cor (L*, a*, b*) e propriedades mecânicas. As suspensões de quitosana contendo clorofila foram aplicadas como revestimento em superfície de papel cartão formando o sistema de material flexível filme-papel cartão (S-FP), reduzindo significativamente o tempo de secagem. Os filmes caracterizaram-se pela homogeneidade, flexibilidade, coloração esverdeada e fácil manuseio. A variação de cor foi visualmente observada no sistema S-FP, alterando irreversivelmente de verde para amarelo quando submetido a temperaturas acima de 50 °C, independentemente da luminosidade. Desta forma, o sistema proposto tem potencial de aplicação como indicador colorimétrico de temperatura na faixa de 50 °C a 75 °C, com a vantagem de simples fabricação, biodegradabilidade e uso de materiais seguros para aplicação em contato direto com alimentos e fármacos, além do baixo custo.Univ Estadual Campinas, UNICAMP, Fac Engn Quim, BR-13083852 Campinas, SP, BrazilUNIFESP, Dept Ciencias Exatas & Terra, Campinas, SP, BrazilUNIFESP, Dept Ciencias Exatas & Terra, Campinas, SP, BrazilWeb of Scienc

    Interferência do avaliador quanto à resposta positiva ao teste do álcool em amostras de leite resfriado.

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    No Brasil a prova do álcool/alizarol é realizada no momento da coleta do leite nas propriedades para verificar a qualidade do mesmo, como um indicativo da estabilidade térmica e ou da acidez do produto. A amostra de leite é cuidadosamente misturada a uma solução alcoólica contendo um indicador de pH (alizarina) e observa-se se ocorre a formação de um precipitado, ou coagulação. O resultado está relacionado à identificação pelo avaliador da formação ou não de grumos e sua intensidade. Na Embrapa Pecuária Sul, foi realizado um experimento, objetivando verificar a influência de diferentes avaliadores sobre a incidência de respostas positivas ao teste do álcool. As amostras foram coletadas pela manhã, refrigeradas e analisadas à tarde quanto a sua reação ao teste. Cada avaliador realizou individualmente a leitura de 6 amostras por vez, em placas de petri individuais, para cada concentração. Foram analisadas 280 amostras para o avaliador 1 (AVAL1), 280 para o avaliador 2 (AVAL2) e 273 amostras para o avaliador 3(AVAL3), totalizando 833 amostras de leite. Houve diferença significativa (P0,05) entre o AVAL2 e o AVAL3. Desta forma, a ocorrência de resultados positivos no teste do álcool sofreu a influência de diferentes avaliadores
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