New “Leaf” Is More Efficient Than Natural Photosynthesis
scientificamerican.com
scientificamerican.com
[1] Study problem on CO2 removal from NASA -- https://www.nasa.gov/pdf/519338main_AP_ED_Chem_CO2Removal_St...
[2] https://www.nasa.gov/mission_pages/station/structure/element...
"In some countries, sales of alcoholic beverages are heavily taxed. In order to avoid paying beverage taxes on alcohol that is not meant to be consumed, the alcohol must be "denatured", or treated with added chemicals to make it unpalatable."
[1] https://en.wikipedia.org/wiki/Denatured_alcohol
I assure you, the after effects of drinking most alcohols are much more devastating than your average spirit.
For reference:
ethanol (Grain alcohol) rat, oral 7,060 mg/kg
isopropanol rat, oral 3,600 mg/kg
isobutanol rat, oral 2,460 mg/kg
Hardy harr harr harr...
As little as 10 mL of pure methanol, ingested, is metabolized into formic acid, which can cause permanent blindness by destruction of the optic nerve. 30 mL is potentially fatal, although the median lethal dose is typically 100 mL (3.4 fl oz) (i.e. 1–2 mL/kg body weight of pure methanol)..
Only a difference in heat levels can still be converted to electricity, for instance by reverse Peltier effect: https://en.wikipedia.org/wiki/Thermoelectric_cooling
It's hard to generate a temperature gradient when you're blasted from the unfiltered Sun on one side, and reflected IR from Earth.
Doesn't change your conclusion though!
If you could replace "power" with "horsepower", you're on the right track!
If you could say "gallons of gas" instead of "power", you mean energy!
wHrs is energy (and kind of a dumb unit. Watts is already joules per second, so you're saying (joules/second)*hours. It would make more sense to just say joules.
Roughly speaking, energy + CO2 = carbon + oxygen. Left to right is photosynthesis. Right to left is fire.
[edit: do be careful when applying this equation in practice! Often, hitting CO2 with a big hammer just yields CO, or carbon monoxide. It's poisonous!]
https://www.quora.com/How-do-the-CDRA-and-Vozdukh-systems-sc...
An artificial leaf that removed CO2 without these downsides might justify a refit.
(RuBisCO as the protein at the center of the process is also quite strange: it's huge and slow. As in 'this ain't funny any more, start working' slow with about a reaction per second.)
[1] I use this a teleological shorthand for "the selective environment has weeded out species that happen to fall on the wrong side of the tradeoff."
Solar panels create an electric current, not fuel. This is a much easier task.
When you read that photosynthesis has 1-2% efficiency, that's because they're measuring the efficiency of converting light into sugar.
[1] https://en.wikipedia.org/wiki/Energy_density#Energy_densitie...
You'll find lipids compare favourably to jet fuel (kerosene), which is distantly related to plant-generated lipids in the first place.
A mole of glucose produces 2800kJ/mol when you burn it. A mole weighs ~180g.
Scaling the denominator of each to 1kg, that's ~46.3MJ/kg for jet fuel and ~15.6MJ/kg for glucose.
Given how biochemically cheap glucose is to produce compared to jet fuel, I'm surprised it's only off the state-of-the-art by a factor of three.
http://www.scientificamerican.com/article/when-it-comes-to-p...
Photosynthesis may be quite efficient internally, but it's not very good at capturing all of the available power. It really is 3-6%, where even cheap solar panels can achieve 15-20% or higher these days.
As others note, plants offer many, er, plantly services. They're (usually) self-supporting, have disease, insect, and pest deterrance capabilities, self-transport water and minerals, and arrange for their own replication.
In many cases, a seed in a hole, or even on bare ground, is all the infrastructure you need to start manufacturing a new plant. Constructed infrastructure tends to have higher investment requirements.
Example of such an evolutionary step. C4 vs C3 photosynthesis.
What's the argument that this is true, rather than it being better than more efficient proteins on some other metric?
Despite this, C3 plants still dominate the planet, so somehow selection pressure hasn't shifted strongly towards C4 plants in non-arid environments.
Or maybe trees are just lazy by nature?
> The device uses solar electricity from a photovoltaic panel to power the chemistry that splits water into oxygen and hydrogen. Microbes within the system then feed on the hydrogen and convert carbon dioxide in the air into alcohol that can be burned as fuel
Only the hydrogen + co2 -> alcohol part uses biological components.
Neither do leaves, they grow out of the air ;)
(arthropod blood)
Seems that increasing the efficiency of photosynthesis could lead to another agricultural revolution.
[1] - https://c4rice.com/the-science/photosynthetic-pathways/
Would not surprise me if it makes such plants more susceptible to diseases.
Because fuel is in lots of cases a better way to store (and transport) energy to be used later and a different time and potentially place.
I came across this link: http://blueskymodel.org/kilowatt-hour
Seems like solar is more or less a break even, where nuclear /wind/geothermal/hydro are pure wins, which makes sense I suppose. Could you manufacture enough of these to consume 1 kilowatt-hour without generating more CO2 in the process than they would consume in their lifecycle?
Let's say you want to generate 1 megawatt-hour of electricity (roughly enough to power an average American household for a month). With coal power, you get roughly 2,000 pounds of carbon dioxide dumped into the atmosphere. [1] To generate the same amount at a nuclear plant, the waste primarily consists of about 3 grams of spent fuel. [2][3]
(And before anyone jumps on me, I'm not trying to dismiss other renewable options... just trying to put nuclear power in perspective.)
[1]: https://www.eia.gov/tools/faqs/faq.cfm?id=74&t=11 [2]: http://www.nei.org/Knowledge-Center/Nuclear-Statistics/US-Nu... [3]: http://www.nei.org/Knowledge-Center/Nuclear-Statistics/On-Si...
Now multiply that by the number of households, and again by twelve to see the amount you'd need to permanently store each year.
Newer designs, and some others, burn spent fuel. Out of the 3 major nuclear reactor incidents, all were old reactor designs. There are new ones that also cannot meltdown in the common understanding of the term.
Don't forget coal mining releases nuclear radiation, since you are unearthing radioactive minerals. So much so, that you are exposed to more radiation in the vicinity of a coal plant than a nuclear reactor.
Here's some info from the royal commission: http://nuclearrc.sa.gov.au/
And from the Citizens' Jury: http://nuclear.yoursay.sa.gov.au/
As I understand it, being paid to store nuclear waste is being viewed as an income stream for the state to backup or replace income from mining operations.
By "still standing" do you include ruins where, say, only part of a wall remains?
Regarding the Pont du Gard, it's intact "due to the importance of its secondary function, as a toll bridge. For centuries the local lords and bishops were responsible for its upkeep, in exchange for the right to levy tolls on travellers using it to cross the river."
I believe bigiain's point is that the structures needed active upkeep to last thousands of years.
Your point is true about people robbing the masonry, but that's closely related to bigiain's comment about "keeping curious humans away from long half life radioactive trash".
I think the supply line from port to the facility would be a softer target and is something the jury and stakeholders would be considering in serious detail.
Watch how it's done: https://www.youtube.com/watch?v=HeVPMzJOFrQ
I think technology creates things, sometimes problems, and then newer technology sometimes addresses these problems. I like the concept of all of these CO2 extraction-for-energy technologies that seem to be popping up lately.
Now, let's hope they can scrub some CO2 from the atmosphere, but not too much! After all, the climate models have been proven to be underestimating the rise of temperature, so the models are deemed not reliable for prediction or forecasting.
Take too much CO2 out, and we're in for a Global Winter. Sort of like the old Twilight Zone episode on TV (Ok, I'm old) where a guy is feverish, and in the background the Earth is getting too hot because of the sun getting closer? He then wakes up and it is snowing outside, and just when you think it is fine and dandy, it is the beginning of an Apocalyptic Winter!
The leaf in this article implies a completely different product. Alcohol... It's quite a different track, and promising if true.
People will probably continue working on this for years and years before something, if anything, comes of it.
https://www.google.co.uk/search?q=urine+fuel
Usually with a platinum catalyst or something rare & expensive
"all we need to do is find a cheaper catalyst"
http://www.autoevolution.com/news/turbocharged-engines-in-fo...
Some of you might wonder how did the engine block resist to such immense detonation inside the combustion chamber. This may not be the answer you were looking for – and most of you might not believe it – but it seems BMW was in fact using seasoned inline 4 cylinder blocks – picked up from several junkyards – for their F1 operations. The interesting part about it was that the blocks were kept out in the cold and urinated upon in order to strengthen their composition.
See also: flying car, battery that lasts for years, and fusion power.
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Getting back to the history lesson, the prospects for the decade look mostly medical.
A few thousand elderly baby boomers are converging on Tehran for Woodstock Four. Europe is desperately trying to import eastern European nurses and home-care assistants; in Japan, whole agricultural villages lie vacant and decaying, ghost communities sucked dry as cities slurp people in like residential black holes.
A rumor is spreading throughout gated old-age communities in the American Midwest, leaving havoc and riots in its wake: Senescence is caused by a slow virus coded into the mammalian genome that evolution hasn't weeded out, and rich billionaires are sitting on the rights to a vaccine. As usual, Charles Darwin gets more than his fair share of the blame. (Less spectacular but more realistic treatments for old age - telomere reconstruction and hexose-denatured protein reduction - are available in private clinics for those who are willing to surrender their pensions.) Progress is expected to speed up shortly, as the fundamental patents in genomic engineering begin to expire; the Free Chromosome Foundation has already published a manifesto calling for the creation of an intellectual-property-free genome with improved replacements for all commonly defective exons.
Experiments in digitizing and running neural wetware under emulation are well established; some radical libertarians claim that, as the technology matures, death - with its draconian curtailment of property and voting rights - will become the biggest civil rights issue of all.
For a small extra fee, most veterinary insurance policies now cover cloning of pets in the event of their accidental and distressing death. Human cloning, for reasons nobody is very clear on anymore, is still illegal in most developed nations - but very few judiciaries push for mandatory abortion of identical twins.
Some commodities are expensive: the price of crude oil has broken eighty Euros a barrel and is edging inexorably up. Other commodities are cheap: computers, for example. Hobbyists print off weird new processor architectures on their home inkjets; middle-aged folks wipe their backsides with diagnostic paper that can tell how their cholesterol levels are tending.
The latest casualties of the march of technological progress are: the high-street clothes shop, the flushing water closet, the Main Battle Tank, and the first generation of quantum computers. New with the decade are cheap enhanced immune systems, brain implants that hook right into the Chomsky organ and talk to their owners through their own speech centers, and widespread public paranoia about limbic spam. Nanotechnology has shattered into a dozen disjoint disciplines, and skeptics are predicting that it will all peter out before long. Philosophers have ceded qualia to engineers, and the current difficult problem in AI is getting software to experience embarrassment.
Fusion power is still, of course, fifty years away.
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http://science.sciencemag.org/content/352/6290/1210
Found a nice quote in the LA Times coverage:
http://www.latimes.com/science/sciencenow/la-sci-sn-bionic-l...
“Stay tuned because Pam and I are on a path to do nitrogen fixation in the same sort of way we’ve just done water splitting,” [Nocera said]
On the other hand, I wonder about the potential for evolution to occur inside reactors like these, essentially self-optimising them over time.
http://www.goodreads.com/book/show/8065404-containment
(Fifth google result searching "photosynthesis venus novel")
I would guess that number should be higher than simple "photosynthesis efficiency".