11 research outputs found

    Revisiting 2D Numerical Models for the 19th century outbursts of η\eta Carinae

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    We present here new results of two-dimensional hydrodynamical simulations of the eruptive events of the 1840s (the great) and the 1890s (the minor) eruptions suffered by the massive star η\eta Car. The two bipolar nebulae commonly known as the Homunculus and the little Homunculus were formed from the interaction of these eruptive events with the underlying stellar wind. As in previous work (Gonzalez et al. 2004a, 2004b), we assume here an interacting, nonspherical multiple-phase wind scenario to explain the shape and the kinematics of both Homunculi, but adopt a more realistic parametrization of the phases of the wind. During the 1890s eruptive event, the outflow speed {\it decreased} for a short period of time. This fact suggests that the little Homunculus is formed when the eruption ends, from the impact of the post-outburst η\eta Car wind (that follows the 1890s event) with the eruptive flow (rather than by the collision of the eruptive flow with the pre-outburst wind, as claimed in previous models; Gonzalez et al. 2004a, 2004b). Our simulations reproduce quite well the shape and the observed expansion speed of the large Homunculus. The little Homunculus (which is embedded within the large Homunculus) becomes Rayleigh-Taylor unstable and develop filamentary structures that resembles the spatial features observed in the polar caps. In addition, we find that the interior cavity between the two Homunculi is partially filled by material that is expelled during the decades following the great eruption. This result may be connected with the observed double-shell structure in the polar lobes of the η\eta Car nebula. Finally, as in previous work, we find the formation of tenuous, equatorial, high-speed features that seem to be related to the observed equatorial skirt of η\eta Car.Comment: accepted for publication in MNRA

    Fresh-blood-free diet for rearing malaria mosquito vectors

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    Mosquito breeding depends on the supply of fresh vertebrate blood, a major bottleneck for large-scale production of Anopheles spp. Feeding alternatives to fresh blood are thus a priority for research, outdoor large-cage trials and control interventions. Several artificial meal compositions were tested and Anopheles oogenesis, egg laying and development into the next generation of adult mosquitoes were followed. We identified blood-substitute-diets that supported ovarian development, egg maturation and fertility as well as, low progeny larval mortality, and normal development of offspring into adult mosquitoes. The formulated diet is an effective artificial meal, free of fresh blood that mimics a vertebrate blood meal and represents an important advance for the sustainability of Anopheles mosquito rearing in captivity.Agência financiadora / Número do subsídio Bill and Melinda Gates Foundation OPP1138841 Fundacao para a Ciencia e Tecnologia GHTM - UID/Multi/04413/201 CCMAR - UID/Multi/04326/2013 UID/Multi/04326/2013 RF SFRH/BPD/89811/2012 FAPEAM, Brazil 19716.UNI472.2459.20022014info:eu-repo/semantics/publishedVersio

    Emulsifier in broiler diets containing different fat sources

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    This present study aimed at evaluating the effect of the addition of an emulsifier to diets containing soybean oil, poultry fat or their blend, on the performance, carcass traits, serum lipid levels, pancreatic lipase concentration and nutrient digestibility of broilers. A randomized block design was applied using a 3 x 2 factorial arrangement, with three fat sources (soybean oil, poultry fat, and a blend of 50% soybean oil and 50% poultry fat) and the addition or not of an emulsifier. In experiment I, broiler performance, carcass traits, serum cholesterol, HDL, and triglyceride levels, and pancreatic lipase activity in 42-day-old broilers were evaluated. In experiment II, dry matter (DM), ether extract (EE), crude protein (CP) and crude fiber (CF) coefficients of digestibility were analyzed. Broilers fed the diet containing soybean oil and emulsifier presented higher body weight, weight gain and better feed conversion ratio. When birds were fed poultry fat and the fat blend (soybean oil and poultry fat) and the emulsifier was added to the diets, pancreatic lipase concentration increased. It was concluded that the use of soybean oil, poultry fat and their blend does no in the diet does not influence the performance, carcass traits, or serum cholesterol, HDL and triglyceride levels of 42-day-old broilers. The addition of emulsifiers to diets containing poultry fat improves ether extract digestibility and increases the production and secretion of pancreatic lipase

    Training small producers in Good Manufacturing Practices for the development of goat milk cheese

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    Abstract Training in Good Manufacturing Practices enhances quality during food processing. This paper evaluates GMP training aimed at improving the chemical, sensory and microbiological quality of goat milk cheese. We worked with 26 families that produce cheese as their main source of income. Semi-structured interviews and observation were conducted to select relevant topics. The manufacturing processes were compared and samples were analyzed before and after GMP training. We trained 80% of the producers. Before receiving training, they used to make cheese from raw milk in unhygienic conditions and with little equipment. The products obtained had bad sensory characteristics, cracks, eyes on the pasta, a high number of aerobic mesophilic bacteria and total coliforms. After training, the producers pasteurized the milk and standardized processing procedures, resulting in final products that contained higher protein and calcium content, suitable sensory characteristics, and a significant reduction in microorganisms, with total coliforms falling to ≤ 5.103 UFC/g. Therefore, this study shows that the manufacturing process and the chemical, sensory and microbiological parameters of goat milk cheese improved after GMP training

    Training small producers in Good Manufacturing Practices for the development of goat milk cheese

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    <div><p>Abstract Training in Good Manufacturing Practices enhances quality during food processing. This paper evaluates GMP training aimed at improving the chemical, sensory and microbiological quality of goat milk cheese. We worked with 26 families that produce cheese as their main source of income. Semi-structured interviews and observation were conducted to select relevant topics. The manufacturing processes were compared and samples were analyzed before and after GMP training. We trained 80% of the producers. Before receiving training, they used to make cheese from raw milk in unhygienic conditions and with little equipment. The products obtained had bad sensory characteristics, cracks, eyes on the pasta, a high number of aerobic mesophilic bacteria and total coliforms. After training, the producers pasteurized the milk and standardized processing procedures, resulting in final products that contained higher protein and calcium content, suitable sensory characteristics, and a significant reduction in microorganisms, with total coliforms falling to ≤ 5.103 UFC/g. Therefore, this study shows that the manufacturing process and the chemical, sensory and microbiological parameters of goat milk cheese improved after GMP training.</p></div
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