994 resultados para 588.1


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Meat and Livestock Australia (MLA) and the Queensland Beef Industry Institute (QBII) used the marketing process Quality Function Deployment (QFD) to determine the education needs of beef producers in northern Australia with regards to beef cattle nutrition management. This is the first time that such a process has been conducted in this sector of the industry. 290 producers from across Queensland, the Northern Territory and Western Australia were interviewed. The results of this process provide considerable insights into issues of concern to northern producers in terms of beef cattle nutrition and how education, extension and research organisations can ensure that they meet the needs of their target audience. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.

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An additional anode catalyst layer with PtRu/C was hot pressed between two Nafion (R) 112 membranes and a conventional direct methanol fuel cell (DMFC) cathode/membrane/anode assembly with the above membranes as separator was fabricated. The additional catalyst layer formed an assistant cell with the cathode to prevent methanol crossover. A simple one-dimensional mathematical model was presented to describe the performance of this new type of membrane electrode assembly system. As seen from both experimental result and model analysis, the additional catalyst layer can not only effectively prevent the methanol crossover, but also generate electrical power with the crossover methanol. The percentage of output power of the assistant cell to the total power analyzed by the model is about 40% under usual condition, which is much higher than that from experimental result, indicating the potential of the development in the DMFC designing. It was also discovered that the electrical power generated from the assistant cell with crossover methanol could take higher percentage in total electrical power when the main DMFC current density became lower.

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En este trabajo resumimos algunas reflexiones sobre el papel que pueden desarrollar la tecnología en el estudio de sistemas semióticos de representación, y que constituyen el núcleo para la comprensión de los procesos de construcción del conocimiento matemático de los estudiantes. La cita corresponde con el resumen de una página publicado.

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Understanding the dynamics of fine sediment transport across the upper intertidal zone is critical in managing the erosion and accretion of intertidal areas, and in managed realignment/estuarine habitat recreation strategies. This paper examines the transfer of sediments between salt marsh and mudflat environments in two contrasting macrotidal estuaries: the Seine (France) and the Medway (UK), using data collected during two joint field seasons undertaken by the Anglo-French RIMEW project (Rives-Manche Estuary Watch). High-resolution ADCP, Altimeter, OBS and ASM measurements from mudflat and marsh surface environments have been combined with sediment trap data to examine short-term sediment transport processes under spring tide and storm flow conditions. In addition, the longer-term accumulation of sediment in each salt marsh system has been examined via radiometric dating of sediment cores. In the Seine, rapid sediment accumulation and expansion of salt marsh areas, and subsequent loss of open intertidal mudflats, is a major problem, and the data collected here indicate a distinct net landward flux of sediments into the marsh interior. Suspended sediment fluxes are much higher than in the Medway estuary (averaging 0.09 g/m(3)/s), and vertical accumulation rates at the salt marsh/mudflat boundary exceed 3 cm/y. Suspended sediment data collected during storm surge conditions indicate that significant in-wash of fine sediments into the marsh interior can occur during (and following) these high-magnitude events. In contrast to the Seine, the Medway is undergoing erosion and general loss of salt marsh areas. Suspended sediment fluxes are of the order of 0.03 g/m(3)/s, and the marsh system here has much lower rates of vertical accretion (sediment accumulation rates are ca. 4 mm/y). Current velocity data for the Medway site indicate higher velocities on the ebb tide than occur on the flood tide, which may be sufficient to remobilise sediments deposited on the previous tide and so force net removal of material from the marsh.

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The electrochemistry of phenol and 4-tert-butyl-phenol is described in [C(2)mim][NTf2] and [C(4)mpyrr][NTf2] ionic liquids. Oxidation of phenol and phenolate is observed at E-p(a) = +1.64 and +0.24 V vs. Ag in both ionic liquids. On the cathodic sweep at a potential of -2.05 P 02 V vs. Ag under an oxygen atmosphere, the production of O-2(2-) dianions triggers the formation of phenolate anions which undergo chemical oxidation to the phenoxyl radical. The phenoxyl radical then reacts with the [NTf2](-) anion of the ionic liquid to form the corresponding phenyl triflate molecule. (c) 2005 Elsevier B.V. All rights reserved.

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Objetivo: Caracterizar a los pacientes que recibieron ventilación mecánica en las unidades de cuidado intensivo (UCI) de la Fundación Santa Fe de Bogotá entre los años 2009 y 2013. Metodología: Se analizó una cohorte retrospectiva de los pacientes en UCI que requirieron soporte ventilatorio mecánico al ingreso a la unidad independientemente de la causa. Resultados: La media de edad de los pacientes fue 63,83 años; el diagnóstico más frecuente de ingreso fue revascularización miocárdica, seguido por neumonía y recambio valvular aórtico; en el 43% de los casos la causa de la falla fue el estado postoperatorio. Los modos ventilatorios más frecuentemente utilizados fueron SIMV (27,5%) y ventilación asistida controlada (26,12%). El 50% de los pacientes fueron ventilados con PEEP < 6 cmH2O. La mortalidad bruta fue del 15%. 22% de los pacientes tuvieron estancia prolongada en UCI. Se aplicó protocolo de retiro de ventilación mecánica en el 77% de los pacientes. La duración de la ventilación mecánica es mayor a medida que aumenta la edad del paciente entre los 60 y los 80 años. La mortalidad es cercana al 50% alrededor de los 50 años y mayor a 80% después de los 80 años. El soporte ventilatorio por cinco o más días aumentó la mortalidad a 80% o más. Discusión y Conclusiones: Estos resultados son comparables a los encontrados en estudios previos. Este estudio puede ser considerado como el primer paso para generar un registro adecuado de la ventilación de la mecánica de las unidades de cuidado intensivo del país.