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Science (non-SETI) :
New light bulb?
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KLiK Send message Joined: 31 Mar 14 Posts: 1304 Credit: 22,994,597 RAC: 60 |
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Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
So, does this mean new life for the incandescent light bulb? Is it 10% more efficient than LED bulbs or 10% better than the old incandescent bulbs? Bob DeWoody My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events. |
Darth Beaver Send message Joined: 20 Aug 99 Posts: 6728 Credit: 21,443,075 RAC: 3 |
Graphene wonderful stuff that mmm now light bulbs . Graphene is being experimented with as Capacitor Battery's with as much power as Lithium ion battery's have only charge in a 20th of the time |
ML1 Send message Joined: 25 Nov 01 Posts: 20140 Credit: 7,508,002 RAC: 20 |
So, does this mean new life for the incandescent light bulb? Is it 10% more efficient than LED bulbs or 10% better than the old incandescent bulbs? [rant] Re Media Ignorance blackening all Science Welcome to wonderful media ignorance of all things science and physics! Unfortunately, that widely repeated example is even more cringe-worthy than the common media confusion between kW (rate of energy conversion/use) and kWh (the 'amount of energy' converted/used). Similarly so for the all too often (mis)use of capitals or non-capitals in units... The 10% clearly states in the original science abstract for up to "10% quantum efficiency". Unfortunately, the media wordsmiths have read the word "quantum" and not understood or even recognized that as a word with meaning. So completely ignoring that and their ignorance, to instead seize upon the more understandable and sexy "efficiency", to then literally make all the rest of various waffle stories up as pure fiction! Sickening! I've seen some horrible howlers that made whatever entire news article unintelligible other than "something" graphene from Manchester with "something" to do with some sort of 'light bulb'. Was all lost in the Canadian connection translations?! Phah! [/rant] In brief summary, my understanding is that sheets of graphene have been doped to form a series of LEDs. A big advantage of graphene for this is mechanical strength, high conductivity, and it is transparent to let the light out, and the finished device is a super-thin flexible (small) sheet of lightweight light! :-) Looks good! I suspect there is a long way to go yet before there is a mass produced range of products on the market. Keep searchin', Martin ps: To directly answer the obvious question of "how efficient" the graphene device is compared to other light sources, a good comparison is given by Wikipedia: Luminous efficacy. Hence, if you assume you want just green light from the grephene, then their device at the quoted 10% would give you 68 lumens/W as compared to around 14 lumens/W for tungsten incandescent bulbs and about the same efficiency as existing LEDs. Note also that well designed cold-electrodes compact fluorescents can achieve similarly good efficiencies. Presumably the graphene advantage is for the flexible low cost construction and the potential to be developed further. Hope of interest. See new freedom: Mageia Linux Take a look for yourself: Linux Format The Future is what We all make IT (GPLv3) |
ML1 Send message Joined: 25 Nov 01 Posts: 20140 Credit: 7,508,002 RAC: 20 |
... I have 2 clear 150W GLS in my attic/loft, and a 100W under my stairs, they are fit for purpose, give good clear immediate light, and I wouldn't change them for $1000! ... You being sentimental? ;-) Keep searchin', Martin See new freedom: Mageia Linux Take a look for yourself: Linux Format The Future is what We all make IT (GPLv3) |
KLiK Send message Joined: 31 Mar 14 Posts: 1304 Credit: 22,994,597 RAC: 60 |
The old incandescent clear and pearl bulbs were brilliant (pun intended!) at providing what was needed from a light bulb, instant good quality light. But they are expensive to manufacture, harmful to the environment, and energy hungry. Modern CFL, LED, and energy saving bulbs are dearer but much more energy efficient. The problem is that they need a warm up time and the light they provide is not as good a quality as GLS bulbs. I have 2 clear 150W GLS in my attic/loft, and a 100W under my stairs, they are fit for purpose, give good clear immediate light, and I wouldn't change them for $1000! LED doesn't need a warm-up time... but CFL, they don't give enough light! that is true... non-profit org. Play4Life in Zagreb, Croatia, EU |
JaundicedEye Send message Joined: 14 Mar 12 Posts: 5375 Credit: 30,870,693 RAC: 1 |
Another claimed use for graphene is 'Atmospheric Ion Harvesting'. I ran across this on YouTube(where else?). Are there any physicists out there that can shoot any holes in this or is it really the power source they claim? https://www.youtube.com/watch?v=ENeDkGce5-4 "Sour Grapes make a bitter Whine." <(0)> |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
Only time will tell. Bob DeWoody My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events. |
janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
Another claimed use for graphene is 'Atmospheric Ion Harvesting'. I ran across this on YouTube(where else?). Are there any physicists out there that can shoot any holes in this or is it really the power source they claim? Watching the clip it seems to work. But why are they talking so much of electric potential (voltage)? It's power we want. In physics, power is the rate of doing work. It is equivalent to an amount of energy consumed per unit time. In the SI system, the unit of power is the joule per second (J/s). But can we use 'Atmospheric Ion Harvesting' in a large scale? |
JaundicedEye Send message Joined: 14 Mar 12 Posts: 5375 Credit: 30,870,693 RAC: 1 |
Electric Potential Energy Potential energy can be defined as the capacity for doing work which arises from position or configuration. In the electrical case, a charge will exert a force on any other charge and potential energy arises from any collection of charges. For example, if a positive charge Q is fixed at some point in space, any other positive charge which is brought close to it will experience a repulsive force and will therefore have potential energy. The potential energy of a test charge q in the vicinity of this source charge will be: where k is Coulomb's constant. In electricity, it is usually more convenient to use the electric potential energy per unit charge, just called electric potential or voltage. Application:Coulomb barrier for nuclear fusion Energy in electron volts. Source: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elepe.html "Sour Grapes make a bitter Whine." <(0)> |
janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
Electric Potential Energy A good analogy of Electric Potential Energy is a waterfall. There are small waterfall that have a high potential. There are big waterfall that have a low potential. What waterfall produce the most Power? |
Darth Beaver Send message Joined: 20 Aug 99 Posts: 6728 Credit: 21,443,075 RAC: 3 |
hehehehe The one with the most water flowing through it and has the biggest generators . Just don't stand in front of the out flow tunnel you will get wet . |
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