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deepak gautam
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Return of incandescent light bulbs as MIT makes them more efficient than LEDs


by Sarah Knapton, Science Editor

11 January 2016 • 5:00pm

Ever since the EU restricted sales of traditional incandescent light bulbs, homeowners have complained about the shortcomings of their energy-efficient replacements.

The clinical white beam of LEDs and frustrating time-delay of ‘green’ lighting has left many hankering after the instant, bright warm glow of traditional filament bulbs.

But now scientists in the US believe they have come up with a solution which could see a reprieve for incandescent bulbs.
"The lighting potential of this technology is exciting."
Prof Gang Chen, MIT

Researchers at MIT have shown that by surrounding the filament with a special crystal structure in the glass they can bounce back the energy which is usually lost in heat, while still allowing the light through.

They refer to the technique as ‘recycling light’ because the energy which would usually escape into the air is redirected back to the filament where it can create new light.

"It recycles the energy that would otherwise be wasted," said Professor Marin Soljacic.
An energy efficient light bulb
An energy efficient light bulb

Usually traditional light bulbs are only about five per cent efficient, with 95 per cent of the energy being lost to the atmosphere. In comparison LED or florescent bulbs manage around 14 per cent efficiency. But the scientists believe that the new bulb could reach efficiency levels of 40 per cent.

And it shows colours far more naturally than modern energy-efficient bulbs. Traditional incandescent bulbs have a ‘colour rendering index’ rating of 100, because they match the hue of objects seen in natural daylight. However even ‘warm’ finish LED or florescent bulbs can only manage an index rating of 80 and most are far less.

"This experimental device is a proof-of-concept, at the low end of performance that could be ultimately achieved by this approach," said principal research scientist Ivan Celanovic.

"An important feature is that our demonstrated device achieves near-ideal rendering of colours.

“That is precisely the reason why incandescent lights remained dominant for so long: their warm light has remained preferable to drab fluorescent lighting for decades.”

Thomas Edison patented the first commercially viable incandescent light bulb more than 130 years ago so that "none but the extravagant" would ever "burn tallow candles.”

It works by heating a thin tungsten wire to temperatures of around 2,700 degrees Celsius. That hot wire emits what is known as black body radiation, a very broad spectrum of light that provides a warm look and a faithful rendering of all colours in a scene.
The first prototype of a light bulb
The first prototype Credit: MIT

However most of the energy is wasted as heat which is why many countries have now phased out the inefficient technology. The UK government announced in 2007 that incandescent bulbs would be phased out by 2011 however many manufacturers still sell them, using a loophole which says they can be put in industrial buildings.

The Energy Saving Trust calculates that typical living room usage of a 60-watt incandescent lightbulb over a year would cost £7.64. Using an equivalent energy efficient fluorescent or ‘CFL’ lightbulb would cost £1.53 per year, while an LED would cost just £1.27.

But if the new bulbs live up to expectations they would cost under 50p a year to run and even improve health.

Previously researchers have warned that the blue light emitted by modern bulbs could be stopping people from getting to sleep at night and campaigners have expressed concerns about the dangerous chemicals they contain.

Prof Gang Chen, Head of the Department of Mechanical Engineering at MIT added: "The lighting potential of this technology is exciting.”

The research was published in the journal Nature Nanotechnology.

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deepak gautam

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I got 2646 points while escaping from a Giant Demon Monkey. Beat that! http://bit.ly/TempleRun2Android
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Air is shot at this sphere of water in Zero Gravity, showing the behavior of its surface tension.

#fluidynamics   #physics   #zerogravity  
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Hello Pluto
Earlier, the space agency released the most detailed picture yet as it hurtled towards the dwarf planet on Tuesday.
The probe was set to grab more pictures and other science data on the object, as it passed 12,500km from the surface.

Controllers got a last health status report, before the robotic craft turned its antenna away from the Earth to concentrate on its target.
Only when New Horizons has its trove of images safely in its onboard memory will it call home again.

This is not expected to happen until just after midnight (GMT) into Wednesday.

Article:
http://www.bbc.com/news/science-environment-33524589
Reference:
http://pluto.jhuapl.edu/

#nasa   #pluto   #space   #newhorizons  
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Bizarre fourth state of water discovered
You already know that water can have three states of matter: solid, liquid and gas. But scientists at the Oak Ridge National Lab (ORNL) have discovered that when it's put under extreme pressure in small spaces, the life-giving liquid can exhibit a strange fourth state known as tunneling.

The water under question was found in super-small six-sided channels in the mineral beryl, which forms the basis for the gems aquamarine and emerald. The channels measure only about five atoms across and function basically as cages that can each trap one water molecule. What the researchers found was that in this incredibly tight space, the water molecule exhibited a characteristic usually only seen at the much smaller quantum level, called tunneling.

Basically, quantum tunneling means that a particle, or in this case a molecule, can overcome a barrier and be on both sides of it at once – or anywhere between. Think of rolling a ball down one side of a hill and up another. The second hill is the barrier and the ball would only have enough energy to climb it to the height from which it was originally dropped. If the second hill was taller, the ball wouldn't be able to roll over it. That's classical physics. Quantum physics and the concept of tunneling means the ball could jump to the other side of the hill with ease or even be found inside the hill – or on both sides of the hill at once.

"In classical physics the atom cannot jump over a barrier if it does not have enough energy for this," ORNL instrument scientist Alexander Kolesnikov tells Gizmag – Kolesnikov is lead author on a paper detailing the discovery published in the April 22 issue of the journal Physical Review Letters. But in the case of the beryl-trapped water his team studied, the water molecules acted according to quantum – not classical – laws of physics.

"This means that the oxygen and hydrogen atoms of the water molecule are 'delocalized' and therefore simultaneously present in all six symmetrically equivalent positions in the channel at the same time," says Kolesnikov. "It's one of those phenomena that only occur in quantum mechanics and has no parallel in our everyday experience."

By using neutron-scattering experiments, the researchers were able to see that the water molecules spread themselves into two corrugated rings, one inside the other. At the center of the ring, the hydrogen atom, which is one third of the water molecule, took on six different orientations at one time. "Tunneling among these orientations means the hydrogen atom is not located at one position, but smeared out in a ring shape," says a report in the online news journal Physics.

"This discovery represents a new fundamental understanding of the behavior of water and the way water utilizes energy," says ORNL co-author Lawrence Anovitz. "It's also interesting to think that those water molecules in your aquamarine or emerald ring – blue and green varieties of
beryl – are undergoing the same quantum tunneling we've seen in our experiments."
Because the ORNL team discovered this new property of water but not exactly why and how it works, Anovitz also says that the finding is sure to get scientists working to uncover the mechanism that leads to the phenomenon.

Kolesnikov adds that the discovery could have implications wherever water is found in extremely tight spaces such as in cell membranes or inside carbon nanotubes. The following video from ORNL provides more details on the discovery.
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Check out WhatsApp Messenger for your smartphone. Download it today from https://whatsapp.com/dl/
WhatsApp Messenger :: cross-platform mobile messaging app for iPhone, BlackBerry, Android, Windows Phone and Nokia. Send text, video, images, audio for free.
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very interesting
 
Guianan cock of the rock
These birds are found in tropical rainforests, near its preferred habitat of rocky outcrops. The males plumage is bright orange and the males have a prominent half-moon crest. The females are brownish in color, and are generally much duller colored than the males. 

During the height of the mating season, males engage in competitive displays in lek, which is a complex courting behavior that is done to attract females. Males and females live separately except when the females choose a mate. The mating success varies based on multiple factors, ranging from the plumage exhibited by a male to the composition of the lek itself. The females choose a male by flying down to the ground and pecking the male on his rump. The male then turns around and the mating takes place almost immediately

Watch:
https://www.youtube.com/watch?v=jEuZ8aIGaHI

Know more:
http://www.oiseaux-birds.com/card-guianan-cock-of-the-rock.html

Photo via:
http://focusingonwildlife.com/news/ornithologists-map-family-tree-of-mysterious-cotinga-birds/

#biodiversity   #amazingbirds  
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The study appears in the July 17 online version of the journal Current Biology.

When an adult female mosquito needs a blood meal to feed her young, she searches for a host — often a human. Many insects, mosquitoes included, are attracted by the odor of the carbon dioxide (CO2) gas that humans and other animals naturally exhale. However, mosquitoes can also pick up other cues that signal a human is nearby. They use their vision to spot a host and thermal sensory information to detect body heat.
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    chemistry, 1994
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