Posts Tagged ‘bridges’
MIT’s Tiny Energy-Harvester Makes Electricity From Low-Frequency Vibrations
Wireless are used for all kinds of things, from monitoring factory machines and oil pipelines to keeping track of pollution. While the efficiency of their energy consumption has improved, the sensors' batteries still need to be changed occasionally. MIT's device, a microelectromechanical system (we prefer the term energy-harvester) makes electricity from the vibrations of foot traffic and other low-power energy sources from the environment, potentially removing the need for batteries completely.
The quarter-sized energy-harvester has improved on the designs of by taking inspiration from the bridges themselves. MIT's energy-harvester consists of a microchip with a bridge-like structure anchored at either end. On the bridge is a weight sitting on one layer of , which naturally gathers electric charge when faced with mechanical stress. Other devices use a cantilever beam instead of a bridge to pick up vibrations, which is much less efficient. MIT's design picks up a wider range of vibrations and produces 100 times more energy than any other harvester available.
The next step for the project is to get the device to pick up lower-frequency vibrations and generate at least 100 microwatts of power, a target that would be able to power a whole network of wireless sensors.
[MIT]
China Opens the World’s Longest Bridge Over Water, Toppling American Record-Holder
The new bridge spans Jiaozhou Bay, on the southern coast of China’s Shandong Peninsula in northeastern China. At 26.4 miles long, it beats Louisiana’s Lake Pontchartrain Causeway — the previous world-record holder — by at least 2 miles, according to the .
Chinese workers toiled at marathon pace to build the bridge in four years, starting at each side and meeting in the middle. The structure has 5,200 pillars and cost at least $2.3 billion, according to Chinese state-run media.
The Guinness officials say the bridge is earthquake- and typhoon-proof, and designed to withstand the impact of a 300,000-ton vessel. It links the port city of Qingdao to the island of Huangdao, cutting drive time from 40 to 20 minutes, according to the state-run .
The reports that Americans are apparently not giving up the world’s longest title without a fight, however. The newspaper talked to Carlton Dufrechou, general manager of the Lake Pontchartrain Causeway, who pointed out that the Jiaozhou bridge has a bend in it, and that the over-water length is only 16 miles, compared to 24 for his bridge.
“Bunch of wannabes,” he said. Read the for his full take, in which he calls the Chinese news “propaganda.”
In any case, the bridge looks pretty neat, especially set to this haunting soundtrack. Check out some aerial views below.
[via ]
Attractive Italian Viaduct Has Wind Turbines Built In
The concept would use the space between an existing viaduct in southern Italy to install 26 wind turbines, which designers Francesco Colarossi, Giovanna Saracino and Luisa Saracino say could provide 36 million kilowatt hours of electricity every year.
The design team conceived the Solar Wind project for a contest that aims to repurpose some old, unused viaducts near Calabria, a region in the toe of Italy. It would cost about $55 million to demolish the viaducts, so town officials for proposals that would re-use them in an environmentally friendly way. The wind turbine bridge took second place.
The proposal also includes a solar-paneled roadway to provide another 11.2 million kilowatt hours, Colarossi and colleagues say. It turns the entire viaduct into a park, with spaces to pull over and take in the view off the Italian coast. Travelers could stop and buy fresh produce grown in solar-powered greenhouses located along the bridge. The whole roadway would be covered in a dense grid of solar cells coated in a thin, transparent plastic, the designers say.
All in all, the system would be capable of generating 40 million kWh each year, enough to power 15,000 homes.
[via ]
Mathematical Model Analyzes Facebook Networks to Prioritize Who Should Receive Vaccinations
People who are "bridges" among different social groups appear as good vaccination bets
The mathematical model focused on the fact that just a few individuals often form the links between different social groups. It also made use of data that came from back in 2005, when Facebook was only open to college students.
The relationships and interactions on five university campuses provided a useful starting scenario for the model to recognize clusters of people and predict bridges between them.
"When a new virus starts spreading, neither the time nor the necessary doses of vaccine to immunize everyone is available," said Marcel Salathe, a postdoc biology researcher at Stanford University. So you'd want a strategy that allows you to protect a population as much as possible given the limited resources that you have."
More details on the Stanford work appear in the April 8 issue of the PLoS Computational Biology.
Scientists have made growing use of social networking data that contains once-personal info. HP Labs researchers recently announced that they used Twitter data to of the latest Hollywood films. And the Pentagon's DARPA challenged people to sift through the disinformation available on social networks such as Twitter and hunt down the physical location of located around the U.S.
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