Scientists advance in quest for alternative energy source

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• Heat from toxic waste sites in developing countries linked to rising cases of disease, disability, early death

A research team from the University of Michigan (U-M), United States (U.S.), has found a way to nearly double the efficiency of a particular class of thermoelectric material that is made with organic semiconductors.

It has been demonstrated that thermoelectric materials can be used to turn waste heat into electricity or to provide refrigeration without any liquid coolants.

According to the study published recently in Nature Materials, the U-M researchers improved upon the state-of-the-art in organic semiconductors by nearly 70 per cent, achieving a figure-of-merit of 0.42 in a compound known as PEDOT:PSS.

Also, a solar-powered airplane that developers hope eventually to pilot around the world landed safely in Phoenix on the first leg of an attempt to fly across the U.S. using only the sun’s energy, project organisers said.

The plane, dubbed the Solar Impulse, took 18 hours and 18 minutes to reach Phoenix on the slow-speed flight, completing the first of five legs with planned stops in Dallas, St. Louis and Washington on the way to a final stop in New York.

According to a report by Reuters, the spindly-looking plane barely hummed as it took off Friday morning from Moffett Field, a joint civil-military airport near San Francisco.

The report reads: “It landed in predawn darkness at Sky Harbor International Airport in Phoenix, according to a statement on the Solar Impulse’s website. The flight crew plans pauses at each stop to wait for favorable weather. It hopes to reach John F. Kennedy International Airport in New York in about two months.

“Swiss pilots and co-founders of the project, Bertrand Piccard and Andre Borschberg, will take turns flying the plane, built with a single-seat cockpit. Piccard was at the controls for the first flight to Arizona.

“The lightweight carbon fiber Solar Impulse has a wingspan of a jumbo jet and the weight of a small car and from a distance resembles a giant floating insect.

“The plane was designed for flights of up to 24 hours at a time and is a test model for a more advanced aircraft the team plans to build to circumnavigate the globe in 2015. It made its first intercontinental flight, from Spain to Morocco, last June.

“The aircraft is propelled by energy collected from 12,000 solar cells built into the wings that simultaneously recharge four large batteries with a storage capacity equivalent to a Tesla electric car that allow it to fly after dark.

“The lightweight design and wingspan allow the plane to conserve energy, but make it vulnerable. It cannot fly in strong wind, fog, rain or clouds. The plane can climb to 28,000 feet and flies at an average of 43 miles per hour (69 km per hour).

“The project began in 2003 with a 10-year budget of €90 million ($112 million) and has involved engineers from Swiss escalator maker Schindler and research aid from Belgian chemicals group Solvay.”

Meanwhile, a study in three developing countries has found that living near a toxic waste site may represent as much of a health threat as some infectious diseases.

According to the study published in Environmental Health Perspectives, researchers analysed 373 toxic waste sites in India, Indonesia and the Philippines, where an estimated 8.6 million people are at risk of exposure to lead, asbestos, hexavalent chromium and other hazardous materials. Among those people at risk, the exposures could cause a loss of around 829,000 years of good health as a result of disease, disability or early death, the team reports May 4 in

In comparison, malaria in these countries, whose combined population is nearly 1.6 billion, causes the loss of 725,000 healthy years while outdoor air pollution claims almost 1.5 million healthy years, according to the World Health Organisation (WHO).

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⏰ Last updated: May 10, 2013 ⏰

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