Light-emitting diode

Iran develops sea rescue drone

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Iranian engineers have tested a drone designed to rescue people at risk of drowning.

The Pars robot has eight propellers and can carry up to three life rings which it can drop within arms-length of potential victims.

The project’s engineers said they were able to reach targets more quickly than a lifeguard in tests carried out near the shore of the Caspian Sea.

But they said more time and funds would be needed to carry out real rescues.

The early-stage experiments were carried out in August, but the details were only recently reported outside Iran by the Robots.net news site.

In them the robot raced against a human lifeguard to reach a person pretending to struggle 75m (247ft) out to sea.

At its fastest, the drone was able to release a life ring to the target within 22 seconds of launch, beating the lifeguard who took about 90 seconds to reach him.

“We carried out 13 tests over a four-day period – some were done at day and a few at night using LED lights,” Amin Rigi, co-founder of Tehran-based RTS Lab told the BBC.

Pars robot
Mr Rigi says he hopes his team’s invention will one day be used to save lives

“We had a little bit of difficulty throwing the life tubes at first, but over the following days the operator got better and became very precise.

“We think that [one day] the drone could be used for rescues at coastlines, for offshore missions from floating marine platforms, and also to carry out rescues when floods occur.”

Mr Rigi said the current prototype can move at 36km/h (22mph), stay airborne for up to 10 minutes, and use GPS location technology to return to base.

For now it requires a human to direct it via a remote control throughout the rest of its flight. However, Mr Rigi said his team aimed to automate more of the process.

“We plan to add image processing for the part of the rescue mission after the drowning person has come into the sight of the robot,” he said.

“From that point it should have the ability to do the rest of mission by itself.”

He added that there are also plans to give the robot the ability to land on water in emergency situations, and for it to use an infrared sensor system to spot people in the dark.

Storm warning

News of the research was welcomed by other roboticists.

“I’m delighted to see aerobot technology being applied to such humanitarian applications,” said Dave Barnes, professor of space and planetary robotics at Aberystwyth University.

“[Delivering] greater autonomy will be a challenge. However, I can envisage such devices using thermal cameras so that they can operate at night and under other similar poor visibility conditions that are a real challenge for human rescuers to deal with when trying to locate drowning victims.”

Yvan Petillot, professor of robotics and a member of Heriot-Watt University‘s Oceans Systems Laboratory, added that the machines might ultimately work best if paired with other artificial intelligence-controlled floating vehicles rather than trying to deliver the life rings themselves.

Graphic of Pars robots on offshore base
RTS envisages coastguards and others having Pars robots ready to deploy from offshore bases

“The current idea might work to monitor beaches in the summer, at least if they can increase the flight-time,” he said.

Pars robot

“But the key problem is that in stormy conditions the controllability of the vehicle is going to be a real issue.

“To me the interesting thing about this technology is the idea of mounting a camera on a flying vehicle, which allows you to explore a bigger area than from a surface craft.

“What you might want is to create a fleet including both kinds of vehicle, with them collaborating together.”

Mr Rigi acknowledged that making the Pars robot stable in harsh weather conditions posed a challenge.

But he added that his team was working to address the problem, and planned to test a more advanced version of the machine in either April or May.

New particle might make quantum condensation at room temperature possible.

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Researchers from FOM Institute AMOLF, Philips Research, and the Autonomous University of Madrid have identified a new type of particle that might make quantum condensation possible at room temperature. The particles, so called PEPs, could be used for fundamental studies on quantum mechanics and applications in lasers and LEDs. The researchers published their results on 18 October in Physical Review Letters.

https://i0.wp.com/cdn.physorg.com/newman/gfx/news/2013/pepssystem.jpg

In quantum condensation (also known as Bose-Einstein condensation) microscopic with different energy levels collapse into a single macroscopic quantum state. In that state, particles can no longer be distinguished. They lose their individuality and so the matter can be considered to be one ‘superparticle’.

Quantum condensation was predicted in the 1920s by Bose and Einstein, who theorised that particles will form a condensate at very low temperatures. The first experimental demonstration of the quantum condensate followed in the 1990s, when a gas of atoms was cooled to just a few billionths of a degree above absolute zero (-273°C). The need for such an extremely low temperature is related to the mass of the particles: the heavier the particles, the lower the temperature at which condensation occurs. This motivated an ongoing search for that may condense at higher temperatures than atoms. The eventual goal is to find particles that form a condensate at .

PEPs

The researchers have created a particle that is a potential candidate for fulfilling the quest: the extremely light plasmon-exciton-polariton (PEP). This particle is hybrid between light and . It consists of photons (light particles), plasmons (particles composed of electrons oscillating in metallic nanoparticles) and excitons (charged particles in ).

The researchers made PEPs using an array of metallic nanoparticles coated with molecules that emit light. This system generates PEPs when it is loaded with energy. Through a careful design of the coupling between plasmons, excitons and photons, the researchers created PEPs with a mass a trillion times smaller than the mass of atoms.

Because of their small mass, these PEPs are suitable candidates for quantum condensation even at room temperature. However, due to losses in the system (such as absorption in the metal) PEPs have a short lifespan, which makes keeping them around long enough to condense a challenge.

First steps

The researchers have shown the first steps towards condensation of PEPs, demonstrating that PEPs cool down as their density increases. However, in the current system cooling down is limited by properties of the organic molecules used in the experiments, which lead to a saturation of the PEP density before sets in. The researchers envisage that it should be possible to overcome these challenges in the future.

Applications

To a large extent, PEPs are composed of photons. Therefore, their decay results in the emission of light. This emitted light has unique properties, which could constitute the basis of new optical devices. In view of recent advances from AMOLF and Philips Research towards improving white LEDs with similar systems, the researchers suggest that from a Bose-Einstein condensate might illuminate our living rooms in the future.

Power from the sea?

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Triboelectric nanogenerator extracts energy from ocean waves.

As sources of renewable energy, sun and wind have one major disadvantage: it isn’t always sunny or windy. Waves in the ocean, on the other hand, are never still. American researchers are now aiming to use waves to produce energy by making use of contact electrification between a patterned plastic nanoarray and water. In the journal Angewandte Chemie, they have introduced an inexpensive and simple prototype of a triboelectric nanogenerator that could be used to produce energy and as a chemical or temperature sensor.

Power from the sea? Triboelectric nanogenerator extracts energy from ocean waves

The triboelectric effect is the build up of an electric charge between two materials through contact and separation – it is commonly experienced when removal of a shirt, especially in dry air, results in crackling. Zhong Lin Wang and a team at the Georgia Institute of Technology in Atlanta have previously developed a triboelectric generator based on two solids that produces enough power to charge a mobile telephone battery. However, high humidity interferes with its operation. How could this technology work with waves in water? The triboelectric effect is not limited to solids; it can also occur with liquids. The only requirement is that specific electronic levels of two substances are close enough together. Water just needs the right partner – maybe a suitable plastic.

As a prototype, the researchers made an insulated plastic tank, whose lid and bottom contain copper foil electrodes. Their system is successful because the inside of the lid is coated with a layer of polydimethylsiloxane (PDMS) patterned with tiny nanoscale pyramids. The tank is filled with deionized water. When the lid is lowered so that the PDMS nanopyramids come into contact with the water, groups of atoms in the PDMS become ionized and negatively charged. A corresponding positively charged layer forms on the surface of the water. The electric charges are maintained when the PDMS layer is lifted out of the water. This produces a potential difference between the PDMS and the water. Hydrophobic PDMS was chosen in order to minimize the amount of water clinging to the surface; the pyramid shapes allow the water to drop off readily. Periodic raising and lowering of the lid while the electrodes are connected to a rectifier and capacitor produces a direct current that can be used to light an array of 60 LEDs. In tests with salt water, the generator produced a lower output, but it could in principle operate with seawater.

The current produced decreases significantly as temperature increases, which could allow this device to be used as a . It also decreases when ethanol is added to the , which suggests potential use of the system as a chemical sensor. By attaching probe molecules with specific binding partners, it may be possible to design sensors for biomolecules.

Terminator Eyes: Hi-tech contact lenses show texts and maps.

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Iafp-photo-torsten-blackwoodmagine texting while driving, or placing a call while showering, without holding your phone in your hands. It’s not sci-fi any more – a new technology allows information like text messages and driving directions to be projected onto a contact lens.

The hardware behind this invention is a spherical curved LCD display that can fit into a contact lens, developed by Ghent University‘s Centre of Microsystems Technology in Belgium.

“This is not science fiction,” chief researcher for the project Jelle De Smet told the Telegraph. “This will never replace the cinema screen for films. But for specific applications it may be interesting to show images such as road directions or projecting text messages from our smart phones straight to our eye.”

These lenses may hit the market within the next few years. In an upgrade from previous models, a new LCD display allows the entire curved surface of the lens to be used.

Earlier versions were based on LEDs, where the display resolution would be limited to only a small number of pixels.

The University of Washington has also been developing new generation of contact lenses that would receive emails and would be able to project information from the Internet, much like in the movie ‘Terminator.’

Other uses of the lens include the concept of adaptable sunglasses – the contact lenses would darken on exposure to light. The lenses could also be used in the fields of medicine and cosmetics.

These advances mark the push for a much wider development of the technology, with the aim of creating a fully pixelated contact lens display as detailed as a television screen.

Tech giants such as Google and Apple have been working to develop similar technology. This past year, Google introduced Project Glass – frames for eyeglasses that project a small computer display into a person’s field of vision. Apple has reportedly patented similar innovations.

Source: http://rt.com

LED streetlamp aims to improve public’s view of stars.

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Researchers believe they have come up with a new type of LED-powered streetlamp that could radically reduce light pollution.

Current designs “leak” large amounts of light in unwanted directions, obscuring views of the stars, wasting energy and making it harder for drivers to see.

The team, based in Mexico and Japan, said they believed their solution was the “best ever reported”.

However, they have yet to turn their theory into a working prototype.

The study – carried out by scientists in Mexico and Taiwan – appears in the open-access journal Optics Express.

LED lens

According to the researchers, conventional street lamps – which use high-pressure sodium or mercury vapour – scatter up to 20% of their energy horizontally or vertically because it is difficult to control their beams.

It is easier to direct light from LEDs because it is being emitted from a smaller area.

So, while manufacturers controlled the direction of the light rays from older lamps using a reflector typically made out of polished aluminium, they can now take advantage of lenses to be more precise.

The researchers say the best LED (light-emitting diode) streetlamps on the market direct about 10% of their energy horizontally or vertically.

But they claim their own invention could further reduce the amount to just 2%.

Their proposed lamp uses three features to ensure the vast majority of its light is limited to a pre-determined rectangular shape covering the road:

The researchers suggest that the set-up would also save on electricity costs since it should require between 10 and 50% less power to illuminate a section of road than current LED streetlamps.

They added that they were now working to build a prototype and hoped to have it completed by October.

LED revolution

London-based light design firm Speirs and Major unveiled anLED-based streetlamp design of its own last year.

The firm’s associate director, Andrew Howis, said the latest study was just one of several efforts under way aimed at tackling the problem of stray light.

“As a result of LEDs it is now possible to place light exactly where it is needed and to greatly reduce spill light and energy wastage,” he said.

“This new research is an example of the innovation in LED optics – of which there are many – which uses a fairly sophisticated optical system to produce an optimised distribution for street lighting.

“It sounds like an advance on what is already available, but of itself is not revolutionary. The change from conventional light sources to LED is the revolution.”

The Campaign to Protect Rural England (CPRE) also gave the new work a qualified welcome.

The lobby group carries out an annual star count to publicise the problem of light pollution which it says disrupts wildlife and people’s sleep.

It noted that the new technology would only be of use if councils were willing to invest in it.

“From 1993 to 2000, light pollution in England increased by 26%, which shows the huge amount of energy and money wasted,” said campaigner Emma Marrington.

“It should be seen as an investment for local authorities to install more efficient street lighting, which will save money and energy waste in the long-term.

“Design is great but councils have to follow through with investment.”

Source:BBC