Tuesday, 18 February 2014

SolarCoin cryptocurrency pays you to go green

A new cryptocurrency with a solar-powered twist could be just the incentive we need to make the shift to clean energy. While most cryptocurrencies are just themed copies of Bitcoin – Dogecoin, based on a famous internet meme, is a notable example – SolarCoins are a bit harder to earn.
SolarCoin is based on Bitcoin technology, but in addition to the usual way of generating coins through mining, crunching numbers to try and solve a cryptographic puzzle, people can earn them as a reward for generating solar energy.
People with solar panels on their house will receive solar renewable energy certificates from their energy company in return for feeding a megawatt-hour of electricity back into the grid. These certificates are already traded for cash, but present one to SolarCoin's organisers and you'll receive one coin – they expect to start distribution in a matter of weeks.
True, the coins are worthless at the moment, but if people start using the currency to support solar energy, it should acquire value. SolarCoin Foundation spokesman Nick Gogerty says the initiative is aiming for $20 to $30 per SolarCoin, effectively providing solar panel owners with a crowdfunded feed-in tariff and encouraging more people to take part.
SolarCoin chose solar rather than another renewable technology because investment in solar panels is easier than in wind turbines, for example. "Solar is interesting because it can be very grassroots," says Gogerty. He and a colleague first conceived of an energy-backed asset in 2011 but couldn't make the idea work without a central bank. Bitcoin makes the bank unnecessary. "We're very thankful for Bitcoin leading the change."
Bitcoin has been accused of wasting energy in the past because of the computing power it takes to mine coins, but Gogerty says that SolarCoin is 50 times more energy-efficient because its algorithm allows the total number of coins to be mined faster – and that's before factoring in the energy boost from new solar panels.
If SolarCoin succeeds, the model could even be applied to other environmental projects, such as conserving the rainforest or endangered species. "If someone can come up with the mechanism and the approach, it would be a great thing," says Gogerty.
Jem Bendell of the University of Cumbria, UK, says SolarCoin is an interesting idea. "What it shows you is we can use this technology that provides a distributed, secure, public, global record for other things." But he cautions that many new coins are launching on the back of the Bitcoin gold rush, and not all will last.

China's Jade Rabbit moon rover showing signs of life

Reports of the moon bunny's death may be somewhat exaggerated. Despite earlier suggestions that China's lunar rover, Yutu – or Jade Rabbit – had been officially declared dead, Chinese state media now say that the rabbit has phoned home. It remains unclear, though, whether the rover is healthy enough to continue its mission.
A news statement from state media agency Xinhua reports that the Chinese space agency is seeing signs of life from Yutu. And a website that records amateur monitoring of radio signals from space has received a downlink signal from Yutu, according to the Planetary Society.
Getting a signal from the rover raises hopes that all is not lost. According to Xinhua, a mission member has said: "The situation of the little rabbit is improving, with a little indication of awakening. Wait a while more."

Early mourning

Yutu's troubles began last month, just six weeks into its three-month mission. China's Chang'e-3 lander touched down on the moon on 14 December and released the Yutu rover about 7 hours later. Both machines successfully entered hibernation mode during their first lunar night. On the moon, night lasts for half of each Earthly month and plunges surface temperatures from daytime highs of about 90 °C to below -180 °C.
When the second lunar night rolled around on 25 January the lander went in to hibernation but Yutu appeared to have failed. It is impossible to communicate with the vehicles during lunar night, so mission operators had to wait until the new lunar day on Monday this week to confirm whether Yutu would respond.
Communication was established with Chang'e-3 but today, the ECNS news agency reported efforts to reactive the rover were unsuccessful: "China's first lunar rover, Yutu, could not be restored to full function on Monday as expected, and netizens mourned it on Weibo, China's Twitter-like service."" No other details were given at the time, leading many observers to think the rover was a goner. News of a wake-up signal is hopeful, but there are no verified reports yet on whether the rover is able to receive and carry out orders from mission controllers.

Cold, cold night

The rover's mechanical problems are likely related to critical components that must be protected during the cold lunar night. When temperatures plunge, the rover's mast is designed to fold down to protect delicate instruments, which can then be kept warm by a radioactive heat source. Yutu also needs to angle a solar panel towards the point where the sun will rise to maintain power levels. A mechanical fault in these systems could leave the rover fatally exposed to the dark and bitter cold.
China's space agency has not released any more details, but abrasive lunar dust is a top suspect. Moon soil gets ground up by micrometeoroid impacts into a glassy dust that can then become charged as it is bombarded by solar particles. During the Apollo programme the sharp-edged dust grains wore through astronaut space suits, scratched up mirrors used for laser ranging experiments and caused moon buggies to overheat.
Even if it is the end of the road for Yutu, China's race into space is just getting started. The nation has bold plans for a crewed lunar base. The rover has also helped put the moon back on the map – NASA has recently began a programme working with private companies to build robots for lunar mining.
 

Necklace projectors will throw emails onto the floor


An alternative way to access smartphone content could hang around your neck.
A digital device disguised as a necklace or brooch could one day project email, tweets and text alerts onto nearby surfaces, allowing you to open them with hand gestures.
"The projector gives you a window into the virtual world that you carry around like a flashlight, as a way of serendipitously accessing information," says Christian Winkler at the University of Ulm in Germany. His team's Ambient Mobile Pervasive Display generates a green "SMS" graphic that is projected ahead of the user (see video above). To find out who the message is from, you hold your palm in front of you and the sender's name is projected onto it. To read the message, you make a gesture, such as a subtle swipe, and the text is displayed on your hand.
The idea is that most functions that normally require a screen can be performed in this way. So, to access your running distance from a fitness app, or a football score, you could customise gestures that will project the results on your hand. The team thinks the system will be especially useful in navigation, projecting arrows on the ground, and for location-aware adverts.

Getting focused

Switching from a projection on the ground to a hand image isn't easy because the projector has to alter its focal length instantaneously. But a Kinect-style 3D sensor solves the problem by calculating the distance to the ground and to the user's hand. The projector uses this information to refocus. The 3D sensor is also used to recognise gesture controls.
In a test system – which the team is confident can be scaled down – a laptop carried in a backpack controlled the projector and sent emails and Facebook updates to the device so that it could display them. A consumer version could be feasible in two years for indoor use and later for outdoor use, Winkler says, as LED-based projectors improve in brightness, use less power and shrink in size. New camera and smartphone models already come equipped with built-in projectors.
William Coggshall, an analyst based in Menlo Park, California, who has studied the future of projector technology, is cautious about how useful the proposed system will actually be. "The size and power of a device that could project onto a sidewalk in daylight may make it pretty clunky," he says. "And the hand is not a very flat or uniform screen so a message of any meaningful length might not be very legible."

Fitbit for the mind: Eye-tracker watches your reading

Devices able to log everything you read will soon go mainstream, letting you see for yourself whether your reading habits need revamping ADDICTED to the Mail Online's infamous celebrity tittle-tattle and not spending enough time in Hemingway's company? A new breed of device could soon be logging everything you read, letting you see for yourself whether your reading habits need revamping.The "quantified self" movement has spawned wearable gadgets like Fitbit and FuelBand, which monitor physical fitness, telling you how far you've walked or how many calories you've burned. How about logging how much you read on screens instead? Like a Fitbit for the mind.
      A "cognitive activity tracker" developed by Kai Kunze at Osaka Prefecture University in Japan can tell how many words we read, how often and how fast we read, and even whether we are skim reading or actually concentrating on the content. It could also generate summaries of documents as you read them by logging which passages your eyes dwell on.
Such detail about what we look at, whether on a screen or on paper, is being made possible by the emergence of gaze-trackers – devices that monitor our eyes to analyse where we are looking. Swedish firm Tobii Technology is leading the way in commercialising the technology. It has developed a $99 system that uses infrared cameras trained on the cornea to watch for the eyeball's movements. These cameras can be built into a headset, such as Google Glass, or clipped to the top of a computer screen or tablet.
This year Tobii will launch its first consumer eye-tracking system for video games, in conjunction with gaming headset maker SteelSeries of Copenhagen, Denmark. This will allow in-game characters to react to the player's gaze, adding a spooky level of realism to first-person shooters. Crucially, the low price puts eye-tracking systems within everyone's reach, says Ralf Biedert, Tobii's chief interaction researcher, based in Stockholm.
Kunze is taking the technology in a different direction. In tests on volunteers wearing infrared eye-tracking glasses, his team found that their software could count the number of words read with an accuracy of about 94 per cent, and tell how fast you were reading, purely by looking at the movement of the eyes. By asking their volunteers to read different types of materials – novels, fashion magazines, newspapers, research papers and textbooks – they have shown that these various media can be discerned near perfectly from the way readers' eyes move around their telltale layouts.
For example, users would get Fitbit-style metrics on how much time they spend – or waste – reading celebrity gossip when they should be revising. Or, says Kunze, publishers could work out if textbook designs need rethinking by seeing how readers navigate their pages. If the software knows what the document is – a novel being read on a Kindle, say – then more advanced features can be used. "It could lead to adaptive reading materials in which the computer recognises I have trouble understanding a particular word and changes the text in real time to give me the definition in the next sentence," he says. Kunze will reveal more at the Augmented Human meeting in Kobe, Japan, in March.
Eye-tracking experts are abuzz. "I find it difficult to be consciously aware of my reading habits and my ability to absorb the textual information that surrounds me. So a reading log like this would really provide new insight, and hopefully help me improve," says Jayson Turner at the University of Lancaster, UK, who has developed a system that lets people drag and drop computer files using an eye-tracker. He thinks Kunze's system will be perfect for quickly summarising what fascinates us.
"It could infer which topics we find interesting, filtering out information we find irrelevant and recording what's important for later recall," Turner says.
Biedert says gaze-trackers could have a profound impact. "It's like when the computer mouse was invented: controlling computers with your eyes will be supported in more and more applications 

Thursday, 13 February 2014

vision over 2030 and depend upon the development of our country make Eco friendly earth to our fore coming generation 

A solar cell (also called a photovoltaic cell) is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. It is a form of photoelectric cell (in that its electrical characteristics—e.g. current, voltage, or resistance—vary when light is incident upon it) which, when exposed to light, can generate and support an electric current without being attached to any external voltage source, but do require an external load for power consumption.
The term "photovoltaic" comes from the Greek φῶς (phōs) meaning "light", and from "volt", the unit of electron-motive force, the volt, which in turn comes from the last name of the Italian physicist Alessandro Volta, inventor of the battery (electrochemical cell). The term "photo-voltaic" has been in use in English since 1849.
Photovoltaic is the field of technology and research related to the practical application of photovoltaic cells in producing electricity from light, though it is often used specifically to refer to the generation of electricity from sunlight. Cells can be described as photovoltaic even when the light source is not necessarily sunlight (lamplight, artificial light, etc.). In such cases the cell is sometimes used as a photo detector (for example infrared detectors), detecting light or other electromagnetic radiation near the visible range, or measuring light intensity.
The operation of a photovoltaic (PV) cell requires 3 basic attributes:
  1. The absorption of light, generating either electron-hole pairs or exciton.
  2. The separation of charge carriers of opposite types.
  3. The separate extraction of those carriers to an external circuit.
In contrast, a solar thermal collector supplies heat by absorbing sunlight, for the purpose of either direct heating or indirect electrical power generation. "Photo electrolytic cell" (photo electrochemical cell), on the other hand, refers either to a type of photovoltaic cell (like that developed by A.E. Becquerel and modern dye-sensitized solar cells), or to a device that splits water directly into hydrogen and oxygen using only solar illumination.


Applications

Polycrystalline photovoltaic cells laminated to backing material in a module
Polycrystalline photovoltaic cells
Solar cells are often electrically connected and encapsulated as a module. Photovoltaic modules often have a sheet of glass on the front (sun up) side, allowing light to pass while protecting the semiconductor wafers from abrasion and impact due to wind-driven debris, rain, hail, etc. Solar cells are also usually connected in series in modules, creating an additive voltage. Connecting cells in parallel will yield a higher current; however, very significant problems exist with parallel connections. For example, shadow effects can shut down the weaker (less illuminated) parallel string (a number of series connected cells) causing substantial power loss and even damaging the weaker string because of the excessive reverse bias applied to the shadowed cells by their illuminated partners. Strings of series cells are usually handled independently and not connected in parallel, special paralleling circuits are the exceptions. Although modules can be interconnected to create an array with the desired peak DC voltage and loading current capacity, using independent MPPTs (maximum power point trackers) provides a better solution. In the absence of paralleling circuits, shunt diodes can be used to reduce the power loss due to shadowing in arrays with series/parallel connected cells.
To make practical use of the solar-generated energy, the electricity is most often fed into the electricity grid using inverters (grid-connected photovoltaic systems); in stand-alone systems, batteries are used to store the energy that is not needed immediately. Solar panels can be used to power or recharge portable devices.