Evaluación de ensilaje de triticale inoculado con bacterias homolácticas en minisilos de laboratorio

In two experiments, we studied the characteristics of ensiling and aerobic stability of triticale (x Triticosecale spp.) ensiled with or without a homolactic bacterial inoculant (HBI). The first experiment used 60 vacuum-sealed 0.946 L glass jar mini-silos (GJ) to determine the effect of ensiling on pH, dry matter recovery (DMR) and temperature. Three GJ per treatment were opened on d 0, 1, 2, 3, 5, 7, 14, 30, 105 and 123 of fermentation. Across all lengths of fermentation, inoculation decreased (P<0.05) average silage pH and temperature upon opening the mini-silos but did not influence (P>0.05) DMR versus the Non-HBI silage. Both silages had a similar (P>0.05) pH at the end of 123 d of fermentation. The second experiment compared the nutritional and fermentation characteristics and aerobic stability of triticale ensiled with or without HBI for 123 d in either 3L PVC mini-silos packed manually (PVC) or vacuum-sealed GJ. There was little difference (P>0.05) in silage nutrient content using PVC or GJ mini-silos, nor did inoculation affect these variables. Ensiling triticale decreased (P<0.05) its 30 h neutral detergent fiber (NDF) digestibility, the lowest value being that of Non-HBI/ PVC silage, which differed (P<0.05) from the HBI/PVC silage, but these did not differ (P>0.05) from the GJ silages. Differences among silages were not found (P>0.05) in NDF at 240 h (uNDF240), total tract NDF digestion (TTNDFD) and rate of NDF digestion (NDFkd). Triticale ensiled well in GJ, however the amount of material ensiled may have been too small to detect differences due to inoculation.En el primero de dos experimentos se determinó el efecto sobre el pH, la recuperación de materia seca (RMS) y la temperatura de ensilar triticale (x Triticosecale spp.) con o sin inoculante de bacteria homoláctica (IBH), utilizando 30 minisilos de vidrio de 0.946 L sellados al vacío (GJ) por tratamiento, que se abrieron a los días 0, 1, 2, 3, 5, 7, 14, 30, 105 y 123 de fermentación. Abarcando todos los largos de fermentación, la inoculación redujo (P<0.05) las medias de pH y temperatura al abrir los minisilos, pero no influyó (P>0.05) en la RMS relativo al ensilaje sin IBH. Ambos ensilajes tuvieron un pH similar (P>0.05) al finalizar el periodo de fermentación de 123 d. En el segundo experimento se compararon las características nutricionales, la fermentación y la estabilidad aeróbica del triticale ensilado con o sin IBH durante 123d en minisilos de 3L hechos de PVC y empacados manualmente o de GJ y sellados al vacío. Hubo mínimas diferencias (P>0.05) en el contenido nutricional del ensilaje fermentado en minisilos de PVC o GJ y la inoculación tampoco afectó estas variables. El ensilamiento de triticale disminuyó (P<0.05) la digestibilidad de la fibra detergente neutro (FDN) a las 30 h, correspondiendo el menor valor al ensilaje sin IBH/PVC, que difirió (P0.05) del ensilaje IBH/PVC, pero estos no tuvieron diferencia (P>0.05) con los ensilados en GJ. No hubo diferencia entre los ensilajes (P>0.05) en FDN no degradable a las 240 h (uFDN240), digestibilidad de FDN en el tracto entero (TTNDFD) y la velocidad de digestión de la FDN (NDFkd). El triticale fermentó bien en los minisilos de vidrio, sin embargo, la cantidad de material ensilado puede que no haya sido suficiente para poder detectar diferencias debido a la inoculación

Pecuária de corte frente à emissão de gases de efeito estufa e estratégias diretas e indiretas para mitigar a emissão de metano.

Editado por: Mário De Beni Arrigoni, Cyntia Ludovico Martins, Danilo Domingues Millen, Marco Aurélio Factori, André Luis Coneglian Brichi, Alexandre Perdigão

Numerical simulation of droplet formation in a microchannel device

The formation of droplets is a phenomenon with particular importance in the development of industrial emulsions. The quality of these compounds is associated with droplet size and stability over time. Anna et al. (2003) developed a methodology named ¨flow focusing¨ to improve droplet formation processes for engineering applications. In this work, Computational Fluid Dynamics (CFD) based techniques are used to assess the capacity of a pseudo-2D numerical model to reproduce water droplets formation within silicon oil, as obtained in Anna et al.’s experiments. Average time of droplet onset obtained via numerical analysis was 1.5 times larger than observed experimentally, whereas droplets convection velocity and diameter predictions differed by 40-45% and 60%, respectively. Nevertheless, calculated velocity profiles downstream the discharge slot reproduced the expected free-jet shear layer according to outer/inner flow ratio

CFD simulation of the dispersion of exhaust gases in a traffic-loaded street of Astana, Kazakhstan

The aim of this paper is to consider one of the most traffic-loaded regions of Astana city (Kazakhstan) and to determine the concentration of carbon-monoxide (CO) in the air during the peak hours. CFD analysis based on the SolidWorks-EFD platform was used to simulate the dispersion of contaminants given the estimated emission rates and weather conditions at the crossroad of Bogenbay Batyr and Zhenis Avenues in Astana. Turbulence prediction was based on k-ε model with wall functions. The governing equations were discretized using the finite volume method and a 2nd order spatial scheme. The mesh verification was based on 1% convergence criterion for a 50% of mesh density increment; air pressure near the wall of a selected building was chosen as the parameter to control the convergence. Numerical results are presented for prevailing conditions during all 4 seasons of the year, demonstrating that the highest levels of CO are recorded in summer and reach the values up to 11.2 ppm which are still lower than the maximum level admitted for humans. Nevertheless, obtained results show that Astana is gradually becoming a city that is likely to reach the critical levels of pollutants in the nearest future if control measures are not taken with enough anticipation. As for a future work, it is proposed to perform in-situ validation of specific scenarios to check and support the results obtained with CFD and to develop then specific policies for tackling the problem before it becomes evident

Numerical simulation of droplet formation in a microchannel device

The formation of droplets is a phenomenon with particular importance in the development of industrial emulsions. The quality of these compounds is associated with droplet size and stability over time. Anna et al. (2003) developed a methodology named ¨flow focusing¨ to improve droplet formation processes for engineering applications. In this work, Computational Fluid Dynamics (CFD) based techniques are used to assess the capacity of a pseudo-2D numerical model to reproduce water droplets formation within silicon oil, as obtained in Anna et al.’s experiments. Average time of droplet onset obtained via numerical analysis was 1.5 times larger than observed experimentally, whereas droplets convection velocity and diameter predictions differed by 40-45% and 60%, respectively. Nevertheless, calculated velocity profiles downstream the discharge slot reproduced the expected free-jet shear layer according to outer/inner flow ratio

Estrategias de ahorro de energía eléctrica aplicables a la industria hotelera mexicana

Este trabajo de obtención de grado se diseñó bajo la modalidad de una investigación documental y evaluación económica financiera de un hipotético proyecto de inversión en un hotel ubicado en Quintana Roo, México. El objetivo principal fue recopilar y analizar las iniciativas y experiencias que han tenido organizaciones de la industria hotelera en el extranjero sobre el ahorro de energía eléctrica, y determinar la factibilidad de su implementación en México, así como cuantificar los beneficios económicos derivados de su aplicación y su contribución a la disminución de las emisiones de gases generadores del calentamiento global. Esta investigación presenta las estrategias para el ahorro en el consumo de energía eléctrica que pueden ser adoptadas por hoteles establecidos en México de categoría cinco estrellas, gran turismo y categoría especial (gran industria). No se tomaron para este estudio la pequeña y mediana industria turística mexicana. Con lo expuesto, esta investigación pretende ser la guía para la implementación de prácticas y dispositivos de ahorro de energía eléctrica aplicables en la industria hotelera mexicana