Ultra-low power LEDs claim over unity electrical efficiency. How is it possible to only use 30pW of electrical energy, when the output is 65pW of luminous energy?
It was discovered that diodes doped in a certain way can absorb heat from the environment. Unfortunately, this only works for cases where the voltage is nearly 0. Meaning that you won’t see ‘real life’ applications soon. But they may be used inside electronics.
A light source of a few pW would be difficult to perceive for most people, even in pitch darkness.
Homer to Lisa Simpson (after inventing a perpetual motion machine): Lisa, in this house we respect the rules of thermodynamics!
Source: dvice.com
Why plastic-eating fungi won’t save our wasteful habits
A few months ago lots of news websites, both legit and sensationalist boomed with the seemingly incredible study that a certain fungi class, mainly hailing from the Amazon jungle, slowly degrade polyurethane (PUR) to simpler chemicals like acetates and CO2.
Why this won’t work to solve the landfill porblem we have? Many reasons:
- adapting a microorganism to work in any environment, including one filled with a toxic atmosphere and dry conditions may proove troublesome
- this may unbalance ecosystems more, adding to the damage
- ridiculous idea to implement on a large scale - how exactly are we going to get feedback?
- not that many plastics are PUR. The main use is in insulating foam. Your bottles are PET, clothes are polyesters (PS), industry use polypropylene (PP)…
- alternative treatments, such as subjection to intense UV bursts and microwaves show more promise for rapid degradation
Source: aem.asm.org
Reduce Your Christmas Rubbish
A mid-sized city throws enough packing ribbons to wrap arround the Earth’s equator if this article is to be beleived.
You may have noticed your refuse sack getting larger these few days. 30% on average larger.
Even if you don’t have a particularly hippie-green mindset, you may appreciate a few of the tips there regarding the reuse of christmas gift wrapping. Wrapping is not cheap for a reason: a good part of the price goes towards landfill, one-time use only.
Source: manassascity.org
Christmas lights and power consumption
An average town of 300 000 - 400k people needs an extra 1 to 1,5MWh during Christmas to keep the lighting working. Of this power, 2/3 is due to domestic lighting alone. To bring these numbers into scale, a conventional coal power plant assures 50-100MW of energy, whilst a single nuclear reactor provides 0.6-1GWh. During Diwali this figure would be certainly bigger.
In order to estimate this figure the following assumptions were made: 5W decorating incandescent bulbs, 1W LEDs, blinked 1/8W LED strips& optic fibre, coventional 25W christmas tree lights. 90k inhabitable homes, of which 75% would be in occupancy at the time. 2 main roads stretching a total of 50km and additional 15 important streets that are decorated by the city council.
The blue glow of an operational nuclear reactor. This is effect is called Cherekov radiation, and happens in a similar fashion to how a sonic bang is produced with a jet engine. Here, neutrons are refracted against the cooling pool, changing wave lengths.
Source: Wikipedia
