środa, 13 lipca 2011
Blog - Tracking Attention, Social Activity, and Our Environment
wtorek, 12 lipca 2011
Blog - Would you Take Medical Advice from An iPhone?
Blog - Sulphur Breakthrough Significantly Boosts Lithium Battery Capacity
poniedziałek, 11 lipca 2011
Virtual Grocery Shopping
TechNewsWorld
A Futures Market for Computer Security
niedziela, 10 lipca 2011
A Less Wasteful Way to Deal with Wastewater
An Israeli company called Emefcy has developed a process that promises to decrease the energy drain of wastewater treatment. This week, Energy Technology Ventures—a joint venture between GE, NRG Energy, and ConocoPhillips—invested in the company, marking the venture's first-ever investment in a non-U.S. company.
Conventional wastewater treatment consumes 2 percent of global power capacity, some 80,000 megawatts, at a cost of $40 billion per year.
Using conventional microbial fuel-cell technology and its own proprietary engineering, Emefcy harvests energy from wastewater, generating enough to power the entire treatment process. In the treatment of particularly carbon-rich industrial wastewater, the company says, the process produces excess electricity that can be fed back into the grid at a profit.
In microbial fuel cells, naturally occurring microorganisms oxidize wastewater. An anode and cathode, placed a critical distance apart in the water, create an electrical circuit from the electrons gained from this oxidation.
Ely Cohen, Emefcy's vice president of marketing, says the company's process reduces the total cost of wastewater treatment by 30 to 40 percent by eliminating spending on energy, and also reduces the amount of sludge that must be trucked away afterward by up to 80 percent.
Traditional wastewater treatment involves forcing air through the water to aerate it. This is also important to the activity of the microbial cells. Emefcy exposes more wastewater to air but without the energy-intensive process of pumping air through water. Instead, the wastewater flows through a "biogenic reactor" made of tubes 1.7 meters in diameter and four meters high. Inside the tubes, water and air flow alongside each other separated by a membrane.
"The reactor is split into two areas," says Emefcy CEO Eytan Levy. "In one area there is a lot of wastewater but there is no air. In the other area there is air but no wastewater. These two areas are separated by a membrane wall and both areas are connected to an electrically-conductive surface on which the bacteria grows."
The electrons produced by the bacteria flow towards the oxygen in the air through nanowires made of naturally-occurring hair-like projections found on the surface of the microbes. "Under these reactor conditions the bacteria develop the ability to convert these pili to become electrically conductive and it behaves just like a metallic wire," says Levy.
The electrodes used are made of a coated plastic, which makes them cheaper, and easier to maintain.
Each stack can process 10 cubic meters of wastewater a day, and has a planned lifespan of 15 years. Stacks can be added on a modular basis, avoiding the need for a large up-front investment in infrastructure. Emefcy hope to begin industrial production this month, with first sales targeted for early 2012.
Blog - Chinese Competitor for Android Doubles Down on Web Apps
sobota, 9 lipca 2011
Blog - Virtual World Study Reveals the Origin of Good and Bad Behavior Patterns
Chinese Solar Companies Thrive on Manufacturing Innovations
piątek, 8 lipca 2011
Was the Space Shuttle a Mistake?
Facebook adds Skype video chat feature
czwartek, 7 lipca 2011
Beware, some Google+ 'invites' are spam
The e-mails mimic actual messages from the new social network, Sophos security says
Links don't appear to upload viruses or other malwareRELATED TOPICSSpam EmailGoogle Inc.Viruses and Worms (CNN) -- OK, Google
Microsoft strikes search deal with Baidu
środa, 6 lipca 2011
What if Generation Dora overruns Facebook?
Israel to Get Electric Car Battery Swap Stations
Next month, Better Place, a startup based in California, will begin selling electric cars in Israel that come with subscription packages that include a leased battery and the cost of recharging it. Gasoline is expensive and taxes on gas-powered cars are high in Israel, and the company says the packages could make owning an electric car 20 percent cheaper than owning a gasoline-powered car.
Better Place is trying to solve the biggest challenge to the widespread adoption of electric cars: the limitations imposed by battery chemistry. A battery big enough to give an electric car the same range as the average gas car would be far too large and expensive; and recharging battery packs takes hours at standard outlets, compared to the minutes it takes to refuel a conventional car.
Better Place will sell a new electric sedan made by Renault that has a range of just over 100 miles on a charge—enough for most daily commutes. For longer trips, Better Place provides battery swap stations, where an automated system switches out a depleted battery for a fully-charged one in less than five minutes. Instead of owning the batteries, the car owners buy subscriptions for a certain number of kilometers of driving per year. They can choose from several plans, much the same way mobile phone owners subscribe to minutes.
The size of Israel limits the number of swap stations needed. What's more, high taxes on gas-powered cars, as well as high prices for gasoline (about $8 a gallon), should help make electric cars more attractive.
Story continues below--Building Bigger, Better Wind Turbines
Wind power is one of the fastest-growing forms of power generation in the United States, with more capacity added onshore than coal and nuclear generation combined over the past four years. But to sustain that high growth rate into the next decade, the industry will have to start tapping offshore wind resources, creating a need for wind turbines that are larger, lower-maintenance, and deliver more power with less weight.
To support research in this area, the U.S. Department of Energy has awarded $7.5 million to six projects, each aiming to develop advanced drivetrains for wind turbines up to 10 megawatts in size. Five of the projects use direct-drive, or gearless, drivetrain technology to increase reliability, and at least two use superconductivity technologies for increased efficiencies and lower weight.
Current designs can't be scaled up economically. Most of the more than 25,000 wind turbines deployed across the United States have a power rating of three megawatts or less and contain complex gearbox systems. The gearboxes match the slow speed of the turbine rotor (between 15 to 20 rotations per minute) to the 2,000 rotations per minute required by their generators. Higher speeds allow for more compact and less expensive generators, but conventional gearboxes—a complex interaction of wheels and bearings—need regular maintenance and are prone to failure, especially at higher speeds.
On land, where turbines are more accessible, gearbox maintenance issues can be tolerated. In rugged offshore environments, the cost of renting a barge and sending crews out to fix or maintain a wind-ravaged machine can be prohibitive. "A gearbox that isn't there is the most reliable gearbox," says Fort Felker, direct of the National Renewable Energy Laboratory's wind technology center.
Story continues below--