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Comment Re:Stop breathing! (Score 1) 559

First, there are plenty of other ways of making cement other than with fly ash (e.g. volcanic ash). Secondly the reason it's called 'fly ash' is because it flies, i.e. escapes with the flue gases, and it's the emission regulations and capture systems which collect the fly ash and make it possible to use in the first place. And third, a lot of fly ash is currently being stored rather than used, as the supply is reduced it will become economical to use those sources.

Comment Re:Not a bad guess (Score 2) 167

each tonne of CO2 implying the consumption of about 360 kilograms of oxygen (mostly coal consumption)

Each tonne of CO2 implies the consumption of 720 kg (0.72 tonnes) of oxygen, as there are two oxygen atoms in each molecule of CO2. Burning hydrocarbon fuels however removes even more oxygen than just that which is bound as CO2, since the hydrogen is also burned to H2O. Acyclic (chain) hydrocarbons as commonly found in fuel oils have approximately twice as many hydrogen atoms as carbon atoms, so each tonne of CO2 produced from burning diesel or other fuel oils (or natural gas) will consume 720 kg of oxygen for itself and another 360 kg of oxygen for the H20.

Comment Re:Prepare to be (Score 1) 532

None of this would have seemed magical to someone from the 1980s, as the precursers to all of it already existed and it was a case of developing the technology further, which given the rate of technological progress at the time seemed very likely. And science-fiction authors and moviemakers had been describing many of those things for at least two decades (Star Trek and 2001 are but examples).

Comment Re:Did KDE survive KDE3-KDE4? (Score 1) 515

KDE used graphics features that should have worked but didn't everywhere. It was single handedly responsible for pulling up graphical support on Linux desktops and resulted in Compiz and all the other comparable Windows and OS X stuff that came about. Without KDE 4 Linux desktops would still have looked like bloody Motif.

Compiz predates KDE4 by about 2 years.

Comment Re:Large enough to help in some other way... (Score 1) 20

Most of that picnic-table sized area are the wings. The fuselage is maybe 10-12 inches across (there is a closeup photo in the article). The spare lifting capacity after batteries is one or two orders of magnitude too low to carry a human. On the other hand it won't do much damage if it hits someone or someone gets too close to the props.

Once you're at the size needed to safely lift a human the requirements for same landing and take off around trees, buildings, animals and people are much more stringent and would need a human operator, at which point a small helicopter will be cheaper and easier (at this time anyway, maybe one day ...).

Comment Re:A solution in search of a problem.. (Score 2) 111

You put the keycard (these days its more often chip based I think, but anyway) in the cradle by the door and it has the same effect (turn on/off thelights etc), usually except for one power socket which is used for the fridge. Two guests get two keycards so one is always in the room with them. Simple ... works this way across the world.

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