Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 5
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
A CFD approach to assess the effects of different opening combinations in poultry houses AGRIAMBI
Saraz,Jairo A. O.; Rocha,Keller S. O.; Damasceno,Flavio A.; Tinoco,Ilda F. F.; Osorio,Robinson; Tobón,Julio C. A..
ABSTRACT The aim of this study was to use computational fluids dynamics (CFD) to evaluate hygiene and comfort conditions in function of temperature level and ammonia (NH3) concentration during the night in commercial poultry houses used in Brazil and countries with tropical and subtropical climates. Four models with different curtain heights and different air inlet and outlet positions were used, adopting the open building typology without thermal insulation. The validated CFD model did not present statistical differences from the experimental data, making it possible to use this model to predict the behavior in the four proposed cases. This model can be used to improve the internal conditions of the poultry facilities during the night and could be an...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Natural ventilation; Ammonia concentration; Computational simulation.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017001200852
Imagem não selecionada

Imprime registro no formato completo
Cattleya walkeriana growth in different micropropagation systems Ciência Rural
Moreira,André Luís; Silva,Adriano Bortolotti da; Santos,Aline; Reis,Caroline Oliveira dos; Landgraf,Paulo Roberto Correa.
The aim of the present research was to verify the in vitro growth of orchids in different systems of micropropagation, being cultivated in a bioreactor, with natural ventilation and conventional systems. Cattleya walkeriana plants were obtained from the germination of seeds in culture medium. After 8 months, seedlings with 1 cm of length were placed in a culture vessel according to the treatments, which counted with two micropropagation systems (conventional and natural ventilation) in three media of culture (liquid, solid with 5 or 6g L-1 of agar). Two additional treatments in bioreactor of temporary and continuous immersion were performed. The design was entirely randomized (ERD), consisting of a 2x3 factorial with two additional treatments, totaling 8...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Bioreactor; Temporary immersion; Liquid medium; Natural ventilation; In vitro culture.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782013001000012
Imagem não selecionada

Imprime registro no formato completo
Enhancement of the greenhouse air ventilation rate under climate conditions of central Mexico Agrociencia
Romero-Gómez,Pedro; Choi,Christopher Y.; Lopez-Cruz,Irineo L..
Mexican plastic-covered greenhouses use natural ventilation as the main method to control temperature and humidity. However, no studies on the dynamic behavior of airflow and ventilation rates are available. In the present study, air exchange rates were analyzed in a naturally-ventilated greenhouse in Mexico using Computational Fluid Dynamics (CFD). To enhance greenhouse cooling, roof vent areas and screen characteristics were examined undef various scenarios to quantify ventilation rates. The air exchange rates through the tight insect screen (model S) were about 50 % of those achieved with actual and loose insect screen (model SF) at the same outside wind speed. Enlargement of the roof vent size ftom 6 % (current) to 15 % of the greenhouse-floor area...
Tipo: Info:eu-repo/semantics/article Palavras-chave: CFD; Greenhouse; Natural ventilation; Rates.
Ano: 2010 URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952010000100001
Imagem não selecionada

Imprime registro no formato completo
Retrofitting multi-span dairy buildings to improve indoor environment CIGR Journal
Abdelbary, Khaled M..
Several dairy farms still have old multi-span barns which are encountering several problems in summer and they are: low ventilation rates, non-uniformed air distribution, heat stress and high indoor concentrations of harmful gases. A solution has been suggested, in this study, which is refurbishing the roofs of old multi-span dairy barns by modifying the roof design, increasing the cowshed height and the roof slope angle. In order to implement this new roof design, rigorous experimental measurements and theoretical calculations were carried out to evaluate the indoor environment before and after refurbishment which was determined by measuring and estimating the following parameters: air exchange rate, indoor temperature, gaseous concentrations (NH3, CH4,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Agricultural Engineering Farm Buildings dairy buildings; Roof refurbishment; Natural ventilation; Indoor environment; Air quality; Gaseous emissions.
Ano: 2017 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4228
Imagem não selecionada

Imprime registro no formato completo
Tracer gas technique, air velocity measurement and natural ventilation method for estimating ventilation rates through naturally ventilated barns CIGR Journal
Alaa Kiwan Kiwan; Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Germany.; Werner Berg; Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Germany.; Reiner Brunsch; Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Germany.; Sezin Özcan; K.U. Leuven, Faculty of Bioscience Engineering, Leuven, Belgium.; Hans-Joachim Müller; Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Germany.; Manfred Gläser; Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Germany.; Merike Fiedler; Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Germany.; Christian Ammon; Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Germany.; Daniel Berckmans; K.U. Leuven, Faculty of Bioscience Engineering, Leuven, Belgium..
Naturally ventilated barns have the advantage of providing an energy-efficient and low-noise micro-environment for animals.  Such barns are very common, especially for cattle, which are a major source of ammonia and methane emissions as well as other airborne pollutants. Emission fluxes are calculated as the product of the ventilation rate (VR) and the gas concentration.  The VR of naturally ventilated barns are directly influenced by atmospheric conditions.  Therefore, the estimation of VR involves high uncertainties; furthermore, there is no reference method for VR estimation.  For these reasons, three different methods were investigated to estimate VR through naturally ventilated dairy barns: (1) the tracer gas...
Palavras-chave: Natural ventilation; Tracer gas technique; Radioactive isotope 85Kr; Air velocity; Air exchange rate; Dairy barn.
Ano: 2012 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/1981
Registros recuperados: 5
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional