5 resultados para Anarquismo -- Pakistan
em Universidad Politécnica de Madrid
Resumo:
Sugarcane leaf shows the classical arrangement of cells which defines a C4 species. Vascular bundles consist of xylem, phloem and fibres, surrounded by an outer layer of sclereids and an inner ring of stone cells associated with the phloem. Some sclereids located below and above the vascular bundles act as docking cells and connect the vascular bundle to the internal surfaces of upper and lower layers of the epidermis. A compact mass of sclereids occupies the total internal volume of the leaf edge. Neither docking cells nor the internal mass of sclereids in the edge were markedly coloured by acriflavin or phloroglucinol, indicating the absence of lignin in their cell walls. However, such staining indicated that fibres of the vascular bundle and the external layer of sclereids were strongly lignified. Incubation of leaf discs with an elicitor produced by the pathogen Sporisorium scitamineum increased the thickness of the lignified cell walls of sclereids as well as the mid and small xylem vessels, as a possible mechanical defense response to the potential entry of the pathogen.
Resumo:
A methodology is applied for economic evaluation of water pumping technologies. Different socioeconomic frameworks are considered for Spain, Cuba and Pakistan. The levelised cost of energy is used to determine the best technology. Wind speed, distance to grid, water storage size and elevation are considered. The water elevation has greater influence on wind pumps than on solar PV pumping.
Resumo:
This paper presents a communication interface between supervisory low-cost mobile robots and domestic Wireless Sensor Network (WSN) based on the Zig Bee protocol from different manufacturers. The communication interface allows control and communication with other network devices using the same protocol. The robot can receive information from sensor devices (temperature, humidity, luminosity) and send commands to actuator devices (lights, shutters, thermostats) from different manufacturers. The architecture of the system, the interfaces and devices needed to establish the communication are described in the paper.
Resumo:
Wind power can play an interesting role in irrigation projects in different areas. A methodology can determine the feasibility of the technology and the levels of daily irrigation demand satisfied by windmills at different levels of risk, using tomato (Lycopersicon esculentum Mill) as greenhouse crop. The present work compared the feasibility of the technology and the critical factors involved in three different countries: Cuba, Spain and Pakistan. The study considered as factors the wind speed level, the energy cost, the tomato prices, the reliability and distance to the electrical grid, and the crop development dates, determining the economic feasibility for each combination of factors in each country.
Resumo:
Esta tesis desarrolla una metodología para comparar la viabilidad económica de distintas tecnologías de suministro energético para el bombeo de agua de riego en invernaderos tanto en España, Cuba o Pakistán (países con diferentes estados de desarrollo). En concreto, se analiza el bombeo directo eólico, el bombeo solar fotovoltaico, el bombeo con generadores diesel, y mediante conexión a la red eléctrica. El análisis tuvo en cuenta los recursos eólicos y solar, la altura de elevación, el tamaño de invernadero, la distancia al punto de conexión a la red, las necesidades de almacenamiento de agua y las fechas de siembra. Las comparaciones se realizaron usando un criterio técnico-económico basado en el coste normalizado de la energía de cada tecnología. En los tres países, el bombeo directo eólico no sería económicamente recomendable, en el caso de existir una conexión a la red. Allí donde no existe conexión a la red, la distancia a la red y los recursos eólico y solar disponibles son los factores clave a tener en cuenta a la hora de decidir entre las diferentes tecnologías. Por otro lado, la altura del bombeo del agua tiene una gran influencia sobre la viabilidad económica del bombeo directo eólico, mucho más que, por ejemplo, en el caso del bombeo solar fotovoltaico. En general, los resultados revelan que los factores críticos a tener en cuenta a la hora de elegir la solución energética óptima son diferentes en cada uno de los países. En el caso de España, la proximidad a los puntos de conexión de la red eléctrica determina que ésta sea la mejor opción. El limitado potencial eólico es el factor limitante en Pakistán. En Cuba, la altura del bombeo, la distancia al punto de conexión de la red eléctrica y el almacenamiento de agua necesario son los factores críticos para determinar la tecnología más apropiada para el bombeo al disponer de buenos recursos solar y eólico. ABSTRACT This thesis develops a methodology for comparing the economic feasibility of wind pump technology, solar photovoltaic pumping, diesel generators, and connection to the electrical grid to provide energy for pumping irrigation water in commercial greenhouses in Spain, Cuba and Pakistan (countries with different developmental backgrounds). The analysis studied the importance of the wind and solar resource, the water elevation, the greenhouse size, the distance to the grid, the pumping elevation, the water storage tank volume requirements, and the planting dates. Comparisons were made in terms of the levelised cost of energy associated with each technology. For all three countries, if a grid connection was already in place, installing wind pumps would be economically unwise. Where no grid connection exists, the distance to the grid and the wind and solar resources available are key factors to be taken into consideration when deciding between options. Finally, the water elevation has a major influence on the economic feasibility of wind pump technology, much more than, for example, on solar photovoltaic pumping technology. The results reveal that, generally, the critical factors to consider when making energy management decisions differ depending between countries. In Spain, the proximity of the electrical grid makes the connection to it the best option. In Pakistan, scarce wind resources are a serious limiting factor. Cuba, however, has good wind and solar resources; water elevation, distance to the grid, and water storage needed are the critical factors when determining the economic feasibility of wind pumping.