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Showing posts from March, 2015

Environmental technology (Alternative and clean power ; Education)

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Alternative and clean power The  Tesla Roadster  is the only all-electric sports car for sale and in serial production. It can be plugged into conventional outlets and can be charged fully or partially on  renewable energy , including  solar ,  hydroelectric , geothermal  or  wind power . Principles: Green syndicalism Sustainability Sustainable design Sustainable engineering Scientists continue to search for  clean energy  alternatives to our current power production methods. Some technologies such as anaerobic digestion  produce renewable energy from  waste  materials. The global reduction of  greenhouse gases  is dependent on the adoption of energy conservation technologies at industrial level as well as this clean energy generation. That includes using unleaded gasoline ,  solar energy  and  alternative fuel  vehicles, including  plug-in hybrid  and  hybrid electric  vehicles. Since industrial use of energy accounts for 51% of worldwide energy usage [9]  improv

Environmental technology(part-2)

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Recycling Renewable energy A view across a  reverse osmosis desalination  plant in  Nepal . Renewable energy  is  energy  that can be replenished easily. For years we have been using sources like wood, sun, water, etc. for means for producing energy. Energy that can be produced by natural objects like wood, sun, wind, etc. is considered to be renewable. [1] § Water purification Water purification : The whole idea/concept of having dirt/germ/pollution free water flowing throughout the environment. Many other phenomena lead from this concept of purification of water. Water pollution is the main enemy of this concept, and various campaigns and activists have been organized around the world to help purify water. [2] § Air purification Air purification: Basic and common green plants can be grown indoors to keep air fresh because all plants remove CO 2  and convert it into oxygen . The best examples are:  Dypsis lutescens ,  Sansevieria trifasciata , and  Epipremnum au

Environmental technology (intro)

Environmental technology Environmental technology  ( envirotech ), green technology ( greentech ) or clean technology ( cleantech ) is the application of one or more of  environmental science ,  green chemistry ,  environmental monitoring  and electronic devices to monitor, model and conserve the  natural environment  and resources, and to curb the negative impacts of human involvement. The term is also used to describe sustainable energy generation technologies such as  photovoltaics ,  wind turbines ,  bioreactors , etc.  Sustainable development  is the core of environmental technologies . The term  environmental technologies  is also used to describe a class of electronic devices that can promote sustainable management of resources. Examples Biofiltration Bioreactor Bioremediation Desalination Doubly fed electric machine Energy conservation Energy saving modules Electric vehicles Wave energy Green computing Hydroelectricity Wind power Wind turbine Hydrogen

History of Internet (Networking in outer space and Internet governance)

Networking in outer space The first live Internet link into  low earth orbit  was established on January 22, 2010 when astronaut T. J. Creamer posted the first unassisted update to his Twitter account from the International Space Station , marking the extension of the Internet into space. [54]  (Astronauts at the ISS had used email and Twitter before, but these messages had been relayed to the ground through a NASA data link before being posted by a human proxy.) This personal Web access, which NASA calls the Crew Support LAN, uses the space station's high-speed  Ku band  microwave link. To surf the Web, astronauts can use a station laptop computer to control a desktop computer on Earth, and they can talk to their families and friends on Earth using  Voice over IP  equipment. [55] Communication with spacecraft beyond earth orbit has traditionally been over point-to-point links through the  Deep Space Network . Each such data link must be manually scheduled and configured. I

History of Internet (Global digital divide)

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Global digital divide Internet users in 2012 as a percentage of a country's population Source:  International Telecommunications Union . [39] Fixed broadband Internet subscriptions in 2012 as a percentage of a country's population Source:  International Telecommunications Union . [40] Mobile broadband Internet subscriptions in 2012 as a percentage of a country's population Source:  International Telecommunications Union . [41] While developed countries with technological infrastructures were joining the Internet, developing countries began to experience a  digital divide  separating them from the Internet. On an essentially continental basis, they are building organizations for Internet resource administration and sharing operational experience, as more and more transmission facilities go into place. Africa At the beginning of the 1990s, African countries relied upon X.25  IPSS  and 2400 baud modem UUCP links for international and inter

History of the Internet (part-2)

Precursors The telegraph system is the first fully digital communication system. Thus the Internet has precursors, such as the  telegraph  system, that date back to the 19th century, more than a century before the digital Internet became widely used in the second half of the 1990s. The concept of  data communication  – transmitting data between two different places, connected via some kind of electromagnetic medium, such as radio or an electrical wire –  predates the introduction of the first computers . Such communication systems were typically limited to point to point communication between two end devices.  Telegraph systems  and  telex machines  can be considered early precursors of this kind of communication. Fundamental theoretical work in  data transmission  and  information theory  was developed by  Claude Shannon ,  Harry Nyquist , and  Ralph Hartley , during the early 20th century. Early computers used the technology available at the time to allow communication betwee

History of the Internet (intro)

The  history of the Internet  begins with the development of electronic computers in the 1950s. Initial concepts of  packet networking originated in several computer science laboratories in the United States, Great Britain, and France. The US Department of Defense awarded contracts as early as the 1960s for packet network systems, including the development of the  ARPANET  (which would become the first network to use the  Internet Protocol .) The first message was sent over the ARPANET from computer science Professor Leonard Kleinrock's laboratory at  University of California, Los Angeles  ( UCLA ) to the second network node at  Stanford Research Institute  ( SRI ). Packet switching  networks such as ARPANET,  Mark I  at  NPL in the UK ,  CYCLADES ,  Merit Network ,  Tymnet , and  Telenet , were developed in the late 1960s and early 1970s using a variety of  communications protocols . The ARPANET in particular led to the development of protocols for  internetworking , in which m