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"Generating electricity is not only inefficient, it also makes pedal power less sustainable, less robust and more costly. To begin with, batteries have to be manufactured, and they have to be replaced regularly. This requires energy, which can completely negate the ecological advantage of pedal power. According to this research paper (pdf), the embodied energy of a 150Wh lead-acid battery (like the one offered with the Windstream pedal power generator) is at least 37,500 Wh, which equals 250 full charges of the battery (more sources: 1/2). In other words: if you can deliver 75 watts of power to the battery, you have to pedal for 500 hours in order to generate the energy that was needed to manufacture the battery. Because the life expectancy of a lead-acid battery can be as low as 300 discharge/charge cycles (sources: 1/2), you are basically pedalling to produce the energy required to manufacture the battery. If you also factor in the embodied energy of other electronics and parts, the ecological advantage of a pedal powered generator connected to a battery becomes rather doubtful. It might costs more energy than it delivers."

"Generating electricity is not only inefficient, it also makes pedal power less sustainable, less robust and more costly. To begin with, batteries have to be manufactured, and they have to be replaced regularly. This requires energy, which can completely negate the ecological advantage of pedal power. According to this research paper (pdf), the embodied energy of a 150Wh lead-acid battery (like the one offered with the Windstream pedal power generator) is at least 37,500 Wh, which equals 250 full charges of the battery (more sources: 1/2). In other words: if you can deliver 75 watts of power to the battery, you have to pedal for 500 hours in order to generate the energy that was needed to manufacture the battery. Because the life expectancy of a lead-acid battery can be as low as 300 discharge/charge cycles (sources: 1/2), you are basically pedalling to produce the energy required to manufacture the battery. If you also factor in the embodied energy of other electronics and parts, the ecological advantage of a pedal powered generator connected to a battery becomes rather doubtful. It might costs more energy than it delivers."

"Imagine you could use any kind of small head difference in a river or canal. The power those drops contain might surprise you. We created a technology that can make use of all these small waterfalls or rapids in a way that's safe for the environment. Gone are the days that communities had to choose between having power or fish to eat. Our robust and fish friendly vortex turbiness will generate energy 24/7 at an incredibly low cost of energy. That way you can have a project with high return on investment that improves the world just that little bit. Now, if you look at a river or canal, you'll notice that it's full of these small cascades, that's how nature builds rivers. We have created a distributed turbine system that can combines a large amount of turbines into one big virtual hydropower powerplant. These virtual hydropower plants can be as large as 10MW in power output. That's the power production of a small city! We can do this because our civil structures are designed to be easy to install, and the electronics and robust power take-offs are designed to keep working with minimal maintenance. The energy produced can be directly connected to your appliances or machinery, and at the same time connected to the national distribution grid, so you can inject the unused power to it, maximizing the revenue through a net billing connection."

"Our new blog is designed to radically reduce the energy use associated with accessing our content. Low-tech Magazine was born in 2007 and has seen minimal changes ever since. Because a website redesign was long overdue - and because we try to practice what we preach - we decided to build a low-tech, self-hosted, and solar-powered version of Low-tech Magazine. The new blog is designed to radically reduce the energy use associated with accessing our content. Why a Low-tech Website? We were told that the Internet would "dematerialise" society and decrease energy use. Contrary to this projection, it has become a large and rapidly growing consumer of energy itself. In order to offset the negative consequences associated with high energy consumption, renewable energy has been proposed as a means to lower emissions from powering data centers. For example, Greenpeace's yearly ClickClean report ranks major Internet companies based on their use of renewable power sources."

"Abstract Many people believe renewable energy sources to be capable of substituting fossil or nuclear energy. However there exist very few scientifically sound studies, which apply due diligence to substantiating this impression. In the present paper, the case of photovoltaic power sources in regions of moderate insolation is analysed critically by using the concept of Energy Return on Energy Invested (ERoEI, also called EROI). But the methodology for calculating the ERoEI differs greatly from author-to-author. The main differences between solar PV Systems are between the current ERoEI and what is called the extended ERoEI (ERoEI EXT). The current methodology recommended by the International Energy Agency is not strictly applicable for comparing photovoltaic (PV) power generation with other systems. The main reasons are due to the fact that on one hand, solar electricity is very material-intensive, labour-intensive and capital-intensive and on the other hand the solar radiation exhibits a rather low power density."

"Groups is an efficient and powerful solution, providing group-based user membership management, group-based capabilities and content access control. Groups is designed as an efficient, powerful and flexible solution for group-oriented membership and content access control."

" THE POWER TO CREATE Reuse learning assets LabXchange brings together high-quality content from a variety of sources in the form of online learning assets, including videos, assessments, and simulations. Our re-engineered Open edX platform gives users the flexibility to search, select, and insert these assets into their own customized learning pathways. Create your own pathway Users can add material to link the learning assets they select to create their own storylines, clarify new learning objectives, and adapt existing pathways to better meet their needs. Share what you have learned Users will be able to share their pathways privately or with a small group to spark discussion and receive feedback. THE POWER TO EXPERIMENT"

"EdX is a nonprofit online initiative created by founding partners Harvard and MIT and composed of dozens of leading global institutions, the xConsortium. EdX offers interactive online courses and MOOCs from the world's best universities and institutions. Open edX is the open source platform that powers edX courses. Through our commitment to the open source vision, edX code is freely available to the community. Institutions can host their own instances of Open edX and offer their own classes. Educators can extend the platform to build learning tools that precisely meet their needs. And developers can contribute new features to the Open edX platform. Our goal is to build a thriving worldwide community of educators and technologists who share innovative solutions to benefit students everywhere. We invite you to explore Open edX and participate in our growing movement. Frequently Asked Questions What is Open edX? The Open edX platform is a free--and open source--course management system (CMS) that was originally developed by edX. The Open edX platform is used all over the world to host Massive Open Online Courses (MOOCs) as well as smaller classes and training modules."

"EdX is a nonprofit online initiative created by founding partners Harvard and MIT and composed of dozens of leading global institutions, the xConsortium. EdX offers interactive online courses and MOOCs from the world's best universities and institutions. Open edX is the open source platform that powers edX courses. Through our commitment to the open source vision, edX code is freely available to the community. Institutions can host their own instances of Open edX and offer their own classes. Educators can extend the platform to build learning tools that precisely meet their needs. And developers can contribute new features to the Open edX platform. Our goal is to build a thriving worldwide community of educators and technologists who share innovative solutions to benefit students everywhere. We invite you to explore Open edX and participate in our growing movement. Frequently Asked Questions What is Open edX? The Open edX platform is a free--and open source--course management system (CMS) that was originally developed by edX. The Open edX platform is used all over the world to host Massive Open Online Courses (MOOCs) as well as smaller classes and training modules."

Speaking skills. B2 ESL learners

aplicaciones para aprender en movimiento

"Pinta is a free, open source drawing/editing program modeled after Paint.NET. Its goal is to provide users with a simple yet powerful way to draw and manipulate images on Linux, Mac, and Windows."

"A lo largo de los tres siglos que necesitó el capitalismo para consolidarse como sistema hegemónico -en el sentido gramsciano-, se fue imponiendo la ley de la oferta y la demanda, en detrimento de los gremios medievales, que durante siglos impidieron la competencia. Y cambió el significado social del dinero, que ganó un protagonismo central al tiempo que, progresivamente, se justificó el cobro de interés, que había sido condenado durante siglos. Los sistemas políticos europeos se tomaron más en serio la libertad que la igualdad y la fraternidad, de la tríada de valores de 1789 (liberté, égalité, fraternité), y la propiedad privada se erigió en el valor supremo de las constituciones, mientras se expandían por Europa las ideas de Adam Smith y John Locke. El Estado, en su concepción moderna, apareció como garante último de la reproducción del capital como eje ordenador de la sociedad; aunque, eso sí, no exento de tensiones y contradicciones, pues los estados europeos debían -y deben- sostener simultáneamente dos instituciones contradictorias: la acumulación creciente de la riqueza económica y el mantenimiento, al menos formal, de la democracia política. El engranaje capitalista estaba en marcha, pero su despegue sólo fue posible con la Revolución Industrial, que comenzó en la Inglaterra del siglo XVIII y se profundizó y expandió el siglo siguiente, sobre todo, desde el momento en que comenzaron a utilizarse los combustibles fósiles (Fernández Durán y González Reyes, 2014). La ingente cantidad de energía que éstos proveían, junto al desarrollo tecnológico, permitió el abaratamiento de los procesos productivos y la expansión de la industria y, con ello, del consumo. Entre los siglos XVIII y XIX, Europa y Estados Unidos asistieron a un espectacular aumento de la producción: para el historiador Neil McKendrick, fue la primera revolución consumista de la historia. La consecuencia inmediata fue una profundización y aceleración

"The Fairphone is a modular handset designed with repairability and ethical sourcing of its materials as headline features. It sold 60,000 units. Amazingly, for what sounds like a nerd-phone, almost half of those buyers had never owned a smartphone before. Now the Fairphone 2 is launching, and with a totally-new, in-house design. The new phone is even easier to repair, and because it was wholly designed by the FairPhone team, its supply chain is even more responsible than ever. The Fairphone is thicker than the latest iPhone or Samsung flagship, but that's the point. Instead of packing everything into a tiny case and keeping it there with glue, the Fairphone is designed to be taken apart. The lightweight magnesium frame supports modules that can be easily replaced by the user. "We have designed it with an aim to last three to five years, looking at making it robust and modular-for repairability," says Fairphone's chief communications officer, Tessa Wernink. "Obviously how long it lasts depends quite heavily on the user, so what we as a company are doing is offering an ecosystem around the phone that supports long-lasting use, first-hand or second-hand." Inside the case (itself one of several options) you'll find the core unit, containing all the chips and radios; a replaceable battery pack; a display that can be snapped off and replaced without any tools (not even a screwdriver); a receiver unit, which contains the front camera, sensors; the headset connector and microphones; a speaker/vibrator unit; and a camera module. These modules are designed to balance manufacturing complexity with repairability. For instance, the display comes as a standalone unit, but less-vulnerable components are bundled into one module. The camera, which people are most likely to upgrade as better versions become available, is also housed in its own module. That way you don't need to toss out your whole phone just to get a better camera. "In fact, the motto from the maker mo

eBreep is a powerful feedback tool for seminars and lectures

"Este curso como otros años quería hacer algún trabajo artístico para reclamar la atención del alumnado ante el problema de la violencia machista. Estaba cansada de hacer instalaciones centradas en lo luctuoso del día. Lo triste, lo que nos pone los pelos de punta. Quería añadir una nueva palabra a mi serie: CAIDAS, PERFILES, y OFRENDA . Pero deseaba encontrar alguna idea positiva, alejarme de la muerte y reflexionar sobre la esperanza, la salida al problema. Y no se como, se me ocurrió: GRITOS ¿Qué le gritarías a esas mujeres que sufren?. ¿Qué mensajes de apoyo les dirías?.¿Cómo animarlas de alguna manera a salir de esa espiral?. Y así llevé a propuesta a clase. Empecé proponiendo yo algunos de los gritos que se me ocurrían y pedí nuevos a mis alumnos en cada clase. La lista se hacía grande, grande, se repetían las frases, pero fue muy emocionante ver manos levantadas para proponer nuevos gritos y lo claro que mis alumnos lo tenían: ¡PUEDES CON TODO!, ¡NO ESTÁS SOLA!, ¡TU LO VALES!, ¡JUST DO IT!, ¡FEMELE POWER!, ¡QUIÉRETE!, ¡QUE NADA TE PARE!, ¡CREE EN TI!, ¡LUCHA POR LO QUE QUIERES!, ¡FUERA MIEDOS!,¡ ERES ÚNICA!, ¡CUÍDATE, ¡TE LO MERECES!, ¡ERES FUERTE!, ¡PUEDES SALIR!, ¡NO TE RINDAS!, ¡ERES INIGUALABLE!, ¡PAUSE THE GAME AND RESET! ¿Y la técnica?. ¿Como mezclar las imágenes del alumnado con su menajes? Mediante un Agamograph se me ocurrió mezclar retratos de cada uno de ellos con el grito que entre todos queríamos lanzar a esas mujeres que sufren, gritos de apoyo para mujeres con la autoestima por los suelos, faltas de valor por años de violencia y de impotencia."

"... In addition to serving as a great explanatory example of the potential danger of AI, I have realized that paperclip maximizer is also a perfect allegory for capitalism. Where the artificial intelligence sought to maximize paperclips, the capital maximizer seeks to maximize capital. ... While this story of the capital maximizer might strike some as the anti-capitalist rantings of socialist idealism, it is not meant as such. Capitalism is the most powerful machine that humans have ever created. It can realize the benefits of technological progress and leverage them to improving the human condition better than any other economic system yet devised. The problem is in viewing the growth of capital as an ends and not a means. If we do not demand that our systems maximize the well-being of humans and the environment which sustains us, then all is lost."

"... Reclaiming pedagogy as a form of educated and militant hope begins with the crucial recognition that education is not solely about job training and the production of ethically challenged entrepreneurial subjects and that artistic production does not only have to serve market interests, but are also about matters of civic engagement and literacy, critical thinking, and the capacity for democratic agency, action, and change. It is also inextricably connected to the related issues of power, inclusion, and social responsibility.[2] If young people, artists, and other cultural workers are to develop a deep respect for others, a keen sense of the common good, as well as an informed notion of community engagement, pedagogy must be viewed as a cultural, political, and moral force that provides the knowledge, values, and social relations to make such democratic practices possible. In this instance, pedagogy needs to be rigorous, self-reflective, and committed not to the dead zone of instrumental rationality but to the practice of freedom and liberation for the most vulnerable and oppressed, to a critical sensibility capable of advancing the parameters of knowledge, addressing crucial social issues, and connecting private troubles into public issues. Any viable notion of critical pedagogy must overcome the image of education as purely instrumental, as dead zones of the imagination, and sites of oppressive discipline and imposed conformity. ..."

"Drained fertile peatlands around the globe are hotspots for the atmospheric emission of laughing-gas -- a powerful greenhouse gas called nitrous oxide, which is partly responsible for global warming and destruction of the ozone layer, a new study shows. Research into natural peatlands such as fens, swamps and bogs, as well as drained peatlands, found that either draining wet soils or irrigating well drained soils boosts the emission of nitrous oxide significantly. Led by researchers at the University of Birmingham and the University of Tartu, Estonia, the study took in 58 peatland sites around the world. These included locations in the United States, Australia, Brazil, South America, Australia, New Zealand, East Africa, Southeast Asia, Siberia and Europe."

"The cryptocurrency uses as much CO2 a year as 1m transatlantic flights. We need to take it seriously as a climate Bitcoin's electricity usage is enormous. In November, the power consumed by the entire bitcoin network was estimated to be higher than that of the Republic of Ireland. Since then, its demands have only grown. It's now on pace to use just over 42TWh of electricity in a year, placing it ahead of New Zealand and Hungary and just behind Peru, according to estimates from Digiconomist. That's commensurate with CO2 emissions of 20 megatonnes - or roughly 1m transatlantic flights."

"Take a look inside Alibaba's smart warehouse where robots do 70% of the work. They can carry up to 500 kilograms above them around the warehouse floor. They have special sensors to avoid colliding into each other and they can be summoned using wifi. When they run out of battery, they can take themselves to a charging station. A five minute charge can power them for 4/5 hours."