Saturday, September 27, 2008

Power from Wave Energy !

LONDON, England (CNN) -- The renewable energy sector has received a boost with the inauguration of the world's first commercial wave power project off the Portuguese coast.

It is hoped that the Pelamis Wave Energy Converters will provide energy for 15,000 homes.

more photos » Developed by a Scottish engineering company, Pelamis Wave Power Limited, the Pelamis Wave Energy Converters (PWEC) have been towed into position three miles off the coast of Agucadoura in north Portugal.

The first phase of the project is using three PWEC to generate 2.25 megawatts of power at a cost of nine million euros.

If successful, a second phase will see energy generation rise to 21 megawatts from a further 25 machines providing electricity for 15,000 Portuguese homes.

The project is a joint venture between Pelamis Wave Power Limited, Babcock and Brown Ltd -- a global specialist asset manager, Energias de Portugal (EDP) and Portuguese energy group EFACEC.

Named after the sea snake Pelamis, each machine measures 140 meters in length, is 3.5 meters wide and sits partially submerged in the sea.

"Effectively what you have is four long sections making up one machine. Between those sections are three small generating motors," he said.

"The four sections are all joined by hydraulic rams. As the waves run through the machine it pushes the rams in and out. The action of the rams going to and fro pushes hydraulic fluid into a high-pressure reservoir. That high-pressure reservoir then releases the fluid at a steady rate through a generating motor."

This power is fed down to a cable on the sea bed which then links back to a sub-station on shore where it is converted into useable electricity.

The PWEC are, of course, reliant on the weather. Depending on the wave resource, Pelamis predict that the machines will on average produce 25-40 percent of their full power output over the course of a year.

When the full array of 25 machines are in place it is calculated that around 60,000 tons of CO2 will be displaced.

If wave power was fully exploited, the British Wind Energy Association estimates that one-two billion tons of CO2 could be displaced every year.

Ian Fells, emeritus professor of energy conversion at Newcastle University in England, gave this latest development in wave power a cautious welcome.

"It's extraordinarily difficult to design a machine that will cope with the extreme violence of waves. Some wave machines are under the surface all the time -- but they are not as well developed as yet. Pelamis lies in the surface and it remains to be seen how successful it will be," he told CNN.

"But good luck to them. We'll just have to see how it operates over time and how it copes with serious weather conditions."

Professor Fells, a founding chairman of the New and Renewable Energy Center (NaREC) at Blyth, Northumberland, is convinced of the potential of wave power engineering but says it is still in its infancy.

"A few years ago when I was talking about a 500-kilowatt Wavegen machine, I was asked by a reporter how many of these we would need to replace the two nuclear power stations in Scotland, and the answer is 10,000. That puts things into perspective."


Friday, September 26, 2008

Scientists give artificial fingers ‘extra feeling’

Scientists give artificial fingers ‘extra feeling’

Published on Fri, Sep 26, 2008 at 00:22 in Health section


ARTIFICIAL SENSATION : Scientists give artificial hands and fingertips the power of touch.

London: People fitted with artificial hands will not only be able to sense touch, but would "instinctively" stop objects slipping from their grasp, all thanks to a group of researchers, who have developed sensitive limbs and fingers for making artificial limbs more and more life-like.

Scientists at University of Southern California, Los Angeles, have developed artificial hands and fingertips that have the power of touch and can "instinctively" stop objects slipping from their grasp.

Human hands make use of a built-in reflex that automatically estimate the minimum force needed to hold on to an object.

The reflex works by responding to tiny vibrations in the skin as an object starts to slip through our fingers.

However, the reflex mechanism is missing in existing artificial hands, thus operators have to consciously estimate the required force.

"It’s very mentally taxing," Telegraph quoted Jeremy Fishel, a member of the research team, as telling New Scientist.

The researchers have developed a system in which the finger tip consists of a rubber skin, filled with thick silicon gel.

If an object begins to slip, the vibrations in the finger’s elastic skin transmit through the silicon gel to sensors attached to a central acrylic "bone".

The vibration provides instant feedback, telling the motors in the hand to tighten their grip before the vibrations stop.

The bone of the finger is also covered with tiny electrodes, across which a small voltage is applied.

The deformations in the elastic skin caused by holding an object alter the distribution of gel in the fingertip, which changes the amount of electricity that is conducted between the electrodes.

The information could then be transmitted to a pressure device worn on a patch of the hand-operator’s healthy skin, helping them to "feel" what their prosthetic hand is touching.

A prototype of the finger will be presented at the BioRob conference in Scottsdale, Arizona

Wednesday, September 10, 2008

Scientists start world's biggest physics experiment

Scientists start world's biggest physics experiment
Courtesy: Yahoo NEWS.
Wed, Sep 10 06:51 PM

By Robert Evans

GENEVA (Reuters) - International scientists celebrated the successful start of a huge particle-smashing machine on Wednesday aiming to recreate the conditions of the "Big Bang" that created the universe.

Experiments using the Large Hadron Collider (LHC), the biggest and most complex machine ever made, could revamp modern physics and unlock secrets about the universe and its origins.

The project has had to work hard to deny suggestions by some critics that the experiment could create tiny black holes of intense gravity that could suck in the whole planet.

Such fears, fanned by doomsday writers, have spurred huge interest in particle physics before the machine's start-up. Leading scientists have dismissed such concerns as "nonsense."

The debut of the machine that cost 10 billion Swiss francs ($9 billion) registered as a blip on a control room screen at CERN, the European Organisation for Nuclear Research, at about 9:30 a.m. (0730 GMT).

"We've got a beam on the LHC," project leader Lyn Evans told his colleagues, who burst into applause at the news.

The physicists and technicians huddled in the control room cheered loudly again an hour later when the particle beam completed a clockwise trajectory of the accelerator, successfully completing the machine's first major task.

Eventually, the scientists want to send beams in both directions to create tiny collisions at nearly the speed of light, an attempt to recreate on a miniature scale the heat and energy of the Big Bang, a concept of the origin of the universe that dominates scientific thinking.

The Big Bang is thought to have occurred 15 billion years ago when an unimaginably dense and hot object the size of a small coin exploded in a void, spewing out matter that expanded rapidly to create stars, planets and eventually life on Earth.


Problems with the LHC's magnets caused its temperature -- which is kept at minus 271.3 degrees Celsius -- to fluctuate slightly, delaying efforts to send a particle beam in the counter-clockwise direction. The beam started its progression and then was halted.

"This is a hiccup, not a major thing," Rudiger Schmidt, CERN's head of hardware commissioning, told reporters, adding the second rotation should be completed on Wednesday afternoon.

Evans, who wore jeans and running shoes to the start-up, declined to say when those high-energy clashes would begin.

"I don't know how long it will take," he said. "I think what has happened this morning bodes very well that it will go quickly ... This is a machine of enormous complexity. Things can go wrong at any time. But this morning we had a great start."

Once the particle-smashing experiment gets to full speed, data measuring the location of particles to a few millionths of a metre, and the passage of time to billionths of a second, will show how the particles come together, fly apart, or dissolve.

It is in these conditions that scientists hope to find fairly quickly a theoretical particle known as the Higgs Boson, named after Scottish scientist Peter Higgs who first proposed it in 1964, as the answer to the mystery of how matter gains mass.

Without mass, the stars and planets in the universe could never have taken shape in the aeons after the Big Bang, and life could never have begun -- on Earth or, if it exists as many cosmologists believe, on other worlds either.