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sábado, febrero 24, 2007
La educacion comunista en Cuba
Al hacer click arriba veran el video...observen las caras de los muchachos: unos que realizan las tareas con desgano y como si los estuvieran forzando. Debe ser muy fastidioso estar varias horas sometido a contestar lo que la profesora quiere que le contesten. Observen también la rudeza del militar para que una jóven ordene su pies como a él le gusta y después que le pone en alto la cara a la muchachita, ella se fastidia de esa disciplina absurda y vuelve a colocar su cabeza como le plazca.Además, porqué pedir semejanzas con el Ché Guevara si lo lógico es utilizar la moral de MARTI.
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KEEP-VID
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El MIT nos habla del Ethanol
En el Blog que se llama LIFE, THE UNIVERSE.. y que trata sobre ciencia, tecnología y políticas gubernamentales se peued leer un artículo en ingles que proviene del MIT y que toca el tema controversial de su posible producción y uso. Hacre click arriba en el enlace.
Weighing Up the Benefits of Ethanol
Weighing Up the Benefits of Ethanol
Brazil's experience with biofuels
Alfredo Ascanio (askain)
Published 2007-02-24 16:28 (KST)
As some countries are encouraging the production of biofuels from vegetable feedstock, what will be the policy of Brazil in this important area?
Many years ago Brazil began the production of ethanol from sugar cane as a mode of import substitution, deciding that it would be mixed with gasoline.
At times of low crude oil prices, the state would subsidize ethanol, but as oil prices rose, its use was good business. In the United States the initial motivation to produce ethanol from maize was as an aid to agribusiness.
The United States has announced that, for strategic reasons, it will increase the production and importation of ethanol to reduce dependency on foreign oil producers who cannot guarantee the security of their exports.
Biofuels are by no means the optimal solution to the pollution problem, especially if not a by product of the normal cultivation of other crops, e.g., sugar cane, maize, etc.
Attendant environmental damage owing to deforestation and decline in soil fertility could threaten the putative gains. There would be a requirement for more mechanization, the increased use of fertilizers, herbicides, insecticides and fungicides, and more irrigation, this last competing with the needs of domestic and industrial users.
Brazil went from being a great sugar exporter to a producer of ethanol, but to produce ethanol means the loss of more forests and cultivating more of the Earth, to the detriment of food production for human consumption, although agribusiness could see a net gain in income. The contradictions between farm pollution and environmental pollution are obvious.
In order to produce ethanol, petroleum-based fertilizers are required, rather more if the cleared land is in a rainforest area like the Amazon basin, whose fertility declines drastically after the second or third year.
The processing of cane for ethanol consumes a lot of electricity that has to come either from hydropower or the burning of fossil fuels.
Ethanol has two carbon atoms, which means that two molecules of carbon dioxide are produced during the fermentation of one molecule of glucose (sugar). This fermentation and the burning of ethanol release large amounts of carbon dioxide, but this would be more than offset by the fixing of carbon dioxide during photosynthesis if conversion were to be implemented on a world-wide scale.
Two things have been borne out in Brazil's experience. Firstly, it did not prove to be cheaper to produce alcohol than to buy petroleum. Secondly, alcohol did not produce a net energy gain.
Ethanol alcohol production for Brazil has had a positive social impact, because the ethanol industry has spun off a large number of ancillary enterprises as well as other collateral benefits, e.g., in helping to mitigate the polarization of wealth and income.
What we must be clear about is that we will continue to require energy, but that we will not be able to continue introducing carbon dioxide into the biosphere at the rates that have prevailed since the Industrial Revolution.
There are many challenges ahead and much research to be done, but the only really clean source of energy is what comes from the sun and the wind.
©2007 OhmyNews
Other articles by reporter Alfredo Ascanio
Brazil's experience with biofuels
Alfredo Ascanio (askain)
Published 2007-02-24 16:28 (KST)
As some countries are encouraging the production of biofuels from vegetable feedstock, what will be the policy of Brazil in this important area?
Many years ago Brazil began the production of ethanol from sugar cane as a mode of import substitution, deciding that it would be mixed with gasoline.
At times of low crude oil prices, the state would subsidize ethanol, but as oil prices rose, its use was good business. In the United States the initial motivation to produce ethanol from maize was as an aid to agribusiness.
The United States has announced that, for strategic reasons, it will increase the production and importation of ethanol to reduce dependency on foreign oil producers who cannot guarantee the security of their exports.
Biofuels are by no means the optimal solution to the pollution problem, especially if not a by product of the normal cultivation of other crops, e.g., sugar cane, maize, etc.
Attendant environmental damage owing to deforestation and decline in soil fertility could threaten the putative gains. There would be a requirement for more mechanization, the increased use of fertilizers, herbicides, insecticides and fungicides, and more irrigation, this last competing with the needs of domestic and industrial users.
Brazil went from being a great sugar exporter to a producer of ethanol, but to produce ethanol means the loss of more forests and cultivating more of the Earth, to the detriment of food production for human consumption, although agribusiness could see a net gain in income. The contradictions between farm pollution and environmental pollution are obvious.
In order to produce ethanol, petroleum-based fertilizers are required, rather more if the cleared land is in a rainforest area like the Amazon basin, whose fertility declines drastically after the second or third year.
The processing of cane for ethanol consumes a lot of electricity that has to come either from hydropower or the burning of fossil fuels.
Ethanol has two carbon atoms, which means that two molecules of carbon dioxide are produced during the fermentation of one molecule of glucose (sugar). This fermentation and the burning of ethanol release large amounts of carbon dioxide, but this would be more than offset by the fixing of carbon dioxide during photosynthesis if conversion were to be implemented on a world-wide scale.
Two things have been borne out in Brazil's experience. Firstly, it did not prove to be cheaper to produce alcohol than to buy petroleum. Secondly, alcohol did not produce a net energy gain.
Ethanol alcohol production for Brazil has had a positive social impact, because the ethanol industry has spun off a large number of ancillary enterprises as well as other collateral benefits, e.g., in helping to mitigate the polarization of wealth and income.
What we must be clear about is that we will continue to require energy, but that we will not be able to continue introducing carbon dioxide into the biosphere at the rates that have prevailed since the Industrial Revolution.
There are many challenges ahead and much research to be done, but the only really clean source of energy is what comes from the sun and the wind.
©2007 OhmyNews
Other articles by reporter Alfredo Ascanio
viernes, febrero 23, 2007
Nature: la revista internacional sobre la ciencia
La revista NATURE que se puede ver haciendo click arriba trata varios temas interesantes para todos los universitarios.
miércoles, febrero 21, 2007
Y seguimos observando...
El Gusano de la Luz dice:
Después de la fiesta de carnaval: el cansancio; después de la fantasía: la realidad. Venezuela con sus vacaciones de siempre demuestra lo poco que se cambia en estas cosas. Colas, retrasos y muertos. La carne volvió a los mercados, pero a otros costos y de contado. El azúcar sigue su vida clandestina.
Venezuela vivió un carnaval de playas, embotellamientos, alcohol, alta velocidad y más accidentes y muertos que nunca. Sin duda para mitigar la angustia. El retorno es algo más que volver a casa, es enfrentar lo cotidiano de nuevo… y no es nada bonito.
Mientras el presidente, viajaba por el Caribe, con su camisa roja, con su encendido discurso anti norteamericano, que su auditorio se abstiene de aplaudir. Los antillanos quieren la energía barata del venezolano, pero no perder el turismo y la ayuda del norte. A fin de cuentas el mundial de Críquet, se llevaba a cabo en paralelo y sus sentimientos como parte de la comunidad británica les deja algo de orgullo y pertenencia. A su regreso el presidente Chávez se encuentro con el presidente Kirchner, que viene a cambiar el menudo por la morocota.
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