2 resultados para Raïms -- Aclarida

em Universidad Politécnica de Madrid


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The pH, VFA concentration, total gas and met hane production were determined in the rumen of four Sicilo- Sarde rams fitted with permanent canulas. Rams received a ration that included 1.5 kg DM of oat hay and were supplemented with one of four concentrates: CC (10% barley, 43.3% corn, 25% wheat bran, 17.7% soybean meal, 4% sheep Vitamin and Mineral Mixture (VMM)), SC (66% white sorghum, 30% faba, 4% sheep VMM); TC (71% triticale, 18% faba, 7%, soybean meal, 4% VMM) or BC (71.5% barley, 17.5% faba, 7% soybean meal and 4% VMM). 50 ml samples were taken before, 2, 5 and 8 hours after the morning meal. Total gas was determined on rumen content before the morning meal. The rumen pH was statistically different (P<0.05) before and 2 hours after the morning meal among concentrates feed. It was in favour of TC and BC (P<0.05) concentrates but was comparable at the end of the day. The concentration of VFA was significantly higher (P<0.05) for diets TC and BC following the meal and became comparable among concentrates thereafter. The proportion of acetate and butyrate acids evolved in the same way during the day regardless of the regimen. The total volu me of gas was different (P<0.05) among diets, the BC showed the highest value (87.00±17.29 ml) while the lowest value was found in the TC concentrate (56.58±13.06 ml). The CH4 production for the BC was significantly different (P<0.05) from that of TC. Quantities produced by the CC and SC were similar (22.08±4.18vs . 21.16±3.21).

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In this paper the main challenges associated with the migration process towards LTE, will be assessed. These challenges comprise, among others, the next key topics: Reliability, Availability Maintainability and Safety (RAMS) requirements, end to end Quality of Service (QoS) requirements, system performance in high speed scenarios, communication system deployment strategy, and system backward compatibility as well as the future system features for delivering railway services. The practical evaluation of the LTE system capabilities and performance in High Speed Railway (HSR) scenarios, require the development of an LTE demonstrator and an LTE system level simulator. Under this scope, the authors have developed an RF LTE demonstrator, as well as an LTE system level simulator, that will provide valuable information for the assessing of LTE performance and suitability in real HSR scenarios. This work is being developed under the framework of a research project to evaluate the feasibility of LTE to become the new railway communication system. The companies and universities involved in this project are: Technical University of Madrid (UPM), Alcatel Lucent Spain, ADIF (Spanish Railway Infrastructure Manager), Metro de Madrid, AT4 Wireless, the University of A Coruña (UDC) and University of Málaga (UMA).