PROCOM 2007-2008

This paper aims to develop the aerodynamical design and the geometric detrmination of a low veñocities wind tunnel. Was elected an Eiffel type open wind tunnel, according to the required conditions in the test chamber, such as the area and maximum air velocity in the test section; we propose the constructive layout with the tunnel elements and the geometry of them. We performe calculations to determine the flow veloctiy, the cross section and the aerodynamical losses in the characteristic sections of the instalation. We determine the required fan power and it’s selection according to the local market conditions.

This work shows a thermodynamical analysis of a simplified cogeneration system for combined production of electricity and proccess heat. Due to increase of energetic demands, we propose a themodynamics schema based on a steam turbin working in conditions of thermic parity. We describe the thermal and thermal-economics calculations methodology of the system. We compare the thermaleconomics indexes using two types of combustible: natural gas and glycerol (methyled), and through the results obtained, is possible to compare the joint production prices of electricity and heat for the two combustibles proposed.

The Y type injectors are classified as internal mixture injectors and are very useful in industries.The calculation methods are based on the sonic flux conditions to enter to mixture chamber. Inthis work, we present a calculation method for these injectors in the subsonic regime where theoperation conditions such as the injector geometry, the pressure and temperature conditions,the properties and mass spend of gaseous and liquid fuel of atomization are known. Underthese conditions, an analysis of Wigg equation -which determine the drops mean diameter-,show that, in the critic regime only permit us to obtain the lesser spray drops mean diameter.For any other condition, the atomization gas flows under a subsonic regime and the drop meandiameter is greater that the minimum value. Also, we compare between different equationswhich define the drop mean diameter in differents variants of Wigg e...

The aim of this study was to evaluate by simulation the accuracy of the prediction of the breeding value according to the heritability of the trait and the number of progenies. Populations were simulated with six progenies for males (n = 15, 30, 50, 75, 100 and 150) and three for females (n = 1, 2 and 3) and characteristics with three heritability (h2 = 0.098, 0.22 and 0.56). The prediction of the breeding values was calculated by the method of the best unbiased linear predictor and the accuracy was calculated from the diagonal of the matrix of the mixed model equation. It was found that the higher heritability the accuracy was also higher in all scenarios. Regarding the number of progenies per male, accuracy values above 0.9 were obtained when the progeny was greater than 30. In the case of females, the highest accuracies were 0.56 for heritability with values of 0.71, 0.74 and 0.76 for...

Resumen

The relationship between day of collection and embryo recovery was studied inmultiparous adult alpacas. Females with ?7 mm follicles were superovulated, mated withfertile males (day 0 = day of service) and embryos were recovered on day 5 (G1), 6 (G2) and 7 (G3) post copula, where the number and size of corpora lutea were echographicallyevaluated. In Exp. 1, 14 females were slaughtered and embryos were recovered from theuterine horns and the oviduct. In Exp. 2, embryos were recovered in vivo from 21 females.Each uterine horn was flushed with 250 ml of PBS using a Foley catheter; and oviductswere flushed from the utero-tubal junction to the fimbria using 20 ml of PBS. The numberand rate of embryos recovered from the uterine horns was higher in G2 and G3 as comparedto G1 (p<0.05), while in the oviduct was higher in G1. Collected embryos from uterinehorns had the condition of excellent an...

The relationship between day of collection and embryo recovery was studied inmultiparous adult alpacas. Females with ?7 mm follicles were superovulated, mated withfertile males (day 0 = day of service) and embryos were recovered on day 5 (G1), 6 (G2) and 7 (G3) post copula, where the number and size of corpora lutea were echographicallyevaluated. In Exp. 1, 14 females were slaughtered and embryos were recovered from theuterine horns and the oviduct. In Exp. 2, embryos were recovered in vivo from 21 females.Each uterine horn was flushed with 250 ml of PBS using a Foley catheter; and oviductswere flushed from the utero-tubal junction to the fimbria using 20 ml of PBS. The numberand rate of embryos recovered from the uterine horns was higher in G2 and G3 as comparedto G1 (p<0.05), while in the oviduct was higher in G1. Collected embryos from uterinehorns had the condition of excellent an...

The aim of the study was to evaluate in llama embryosthe effect of twocryopreservation methods on the in vivo and in vitro survival rate. Seventy three hatchedblastocysts were recovered by a non-surgical technique at day 6.5 after mating fromsuperstimulated llamas. Receptors were randomly allocated to a control group (n=14),vitrification (n=30) and slow freezing (n=29). On vitrification, embryos were exposed to avitrification solution (VS) containing 20% Glycerol + 20% Ethylene glycol + 0.5 M Sucrose+ 10% fetal calf serum (FCS) + 50 μg/ml gentamicin sulfate, and then plunged into liquidnitrogen in 0.25 ml straws. On the slow freezing, embryos were exposed to phosphatebuffer saline (PBS) with 1.5 M Ethylene glycol + 10% FCS + 50 μg/ml gentamicin sulfate,loaded in 0.25 ml straws, and cooled at a rate of 0.12 °C/min to 5 °C. Then, furthertemperature decrease at 5 °C /min rate, to -20 Â...

El objetivo del estudio fue evaluar el efecto de dos métodos de criopreservación sobre la supervivencia in vivo e in vitro de embriones de llama. Se recuperaron 73 embriones en estadio de blastocisto eclosionado mediante una técnica no quirúrgica a los 6.5 días post servicio en llamas superestimuladas. Las llamas receptoras se distribuyeron aleatoriamente en grupo Control (n = 14), de vitrificación (n=30) y de congelación lenta (n=29). Para la vitrificación, los embriones fueron expuestos a la solución de vitrificación (SV) conteniendo 20% Glicerol + 20% Etilenglicol + 0.5M Sucrosa + 10% suero fetal bovino (SFB) + 50 μg/ml sulfato de gentamicina, y sumergidos en nitrógeno líquido dentro de pajillas de 0.25 ml. Para la congelación lenta, los embriones fueron expuestos a fosfato buffer salino (PBS) con 1.5 M de Etilenglicol + 10% de SFB + 50 μg/ml de sulfato de gentamicina, ...