not the first to think of that.
not the first to think of that.
Change to Propane (110 octane) or LNG (octane 130). Though probably have to retrofit underwing or tip tanks (already some types on market). Both are much cheaper fuels, and engines could be made higher performance with higher compression ratios.
Turboprops are not more efficient.
Diesels get peak efficiencies of 40-45% at car sized, 45-48% at truck sized, 53% for biggest ships. Bump that up a little when operating in cold air at altitude. Small helicopter turboshafts and turboprops for light aircraft are typically 25% efficient. Even the biggest 777 turbofans are only about 40% efficient at sea level. though that rises to mid to high 40's at cruise altitude where it is -60C
They have been doing demos at small scale, but to really pay out big it needs to be done at much larger scale - as the line drag becomes a smaller and smaller loss the bigger you go and the wind stronger the higher they get. Given that most of their challenges are control system related solving them in small scale means the scale up should be far less risky (flying kites is really really hard compared to aircraft etc due to dominating and unknowable future variance of wind speed and direction)
And if you look at it from a simple cost of materials point of view the systems will be far less than 10% the weight of the turbines they replace, while the wind power flux they can access is several times as high at the altitudes they are aiming at. They are predicting less than half the cost of existing wind energy, but might end up even lower.
Fundamentally there is nothing preventing 10's or even eventually 100's of MW per wing, and its a lot easier to stick out at sea or in other tricky geographical locations than trying to assemble the current huge turbines and their towers.
A very unflattering analysis of Rossi's latest:
Get a duty free bottle of champagne, make a 100W heater element with some silicone sealant or an o-ring that you can insert into the top and lock in under high pressure.
Open bottle in toilet, insert heater, put in bag surrounded by insulating clothes inside a plastic bag to prevent release of burning smells. Hook into the onboard laptop power supply in your business class seat, wait about 8-10 hours.
Eventually steam pressure and temperature overwhelms bottle strength. Boom - equivalent of about 3-400g high explosive.
All airport security is obviously bullshit. Men can easily fit 1kg of high explosive up their arses if they are willing to practice, and women have more than one option for hiding such items beyond the view of all scanning.
Even if it was igniting and had good fusion gain, there are such a huge array of serious engineering issues that they have got no economic answers for that it is never going to work commercially. High precision optics in close proximity to nuclear blasts?? High precision targets that cost $10k (but would have to reduce to $0.25 to be commercial) being introduced into a plasma filled chamber at 15Hz that must be positioned with sub mm precision? May as well keep it running now for the materials side of things, but as much as possible fusion R&D budgets should be directed away from NIF and ITER (tokomaks are too big and too expensive to be commercially viable) and towards fusion options with at least some potential for commercial viability like:
General fusion (liquid metal implosion on plasma target), Tri-Alpha, Helion (electromagnetic compression of plasma toroids), Polywell (Inertial electrostatic confinement in a magnetised 'wiffleball' trap).
Also Fission in fast breeders provides a far more certain short term payoff, cheap, managable engineering issues, no nasty tritium to deal with and massively reducing radioactive waste compared to current non-breeding reactors. There is enough accessible Thorium and Uranium to power our civilisation at current levels until the sun kills the earth.
There must be a pretty good chance that USSR and perhaps also China have smuggled nukes into the USA and buried them near important strategic targets like the Pentagon, The Mall, and possibly even some major cities. To give an ultimate and anonymous 1st strike capability. Given how porous US borders are a competent govt backed group could pull this off with very low risk.
Excellent, so at 1% for usps insurance, and with a product that has enormous markup on it (probably >80% for hipster shoes), this business will be profiting with 5% higher sales. Not to mention increasing their profile with their target market due to the religious persecution of the USPS.
God works in mysterious ways.
So why does it appear that water vapour in the atmosphere (upper atmos) has been falling for the last 30 years even as global temperatures and CO2 have been increasing? Faults in the Data or in the Theory?
The only reason that North Korea currently exists is to maintain a few 1000 top officials in relative wealth - but even that wealth is pretty poor compared to the West. If South Korea were to offer the top 10,000 officials in the north $1-100 million each (depending on position) + immunity from prosecution then they could probably reunify Korea within a year, and save themselves a lot of money in the long term.
A number of reviewers have noted that the methodology is somewhat flawed in that the temporal resolution of the proxies used to reconstruct ancient temperatures is very low - up to 500 years, whereas the modern global temperature data that is appended to produce the hockeystick graph is at high resolution.
This, along with the averaging effect of combining numerous noisy proxy data streams has the effect of removing significant features such as the medieval, roman, minoan warming periods where temperatures rose by as much as 2C for periods of 1-300 years. It also removes similar long duration temperature dips.
So ultimately the picture presented of historical temperatures is not realistic, if we were to apply the same temporal low pass filtering to the modern temperature record as well you would not even see the recent temperature rise, and the little ice age would probably disappear as well. Eg look as Gisp2 ice core temp data for a reasonably good picture of historic temperatures:
shows same general trend as this paper, just preserves the frequent 1-500 year temp oscillations
There are quite a few other relatively cheap options below 77K. In particular using vacuum to lower the temperature of liquid Nitrogen is pretty easy and gets you to 64K with the nitrogen still a liquid. Same trick with liquid Oxygen (also dirt cheap) gets you to 55K and liquid Neon is about 25K (and when we run out of easily mineable Helium it will be cheaper than helium). Liquid Hydrogen can be used at down to 14K using evacuation (20K at atmospheric pressure).
if SSDs were made up of several smaller swappable/replaceable SSD chunks in a Raid 5 or 6 setup then that would basically put a stop to unreliable SSDs by giving a recoverable failure mode. It might also make it more practical to use denser and cheaper but shorter life flash memory in the SSDs.
US system is FUBAR, 50million uninsured, huge numbers of medical induced bankruptcies (for the heinous crime of being unlucky), lower life expectancy.
Nationalised single payer with optional extra private coverage is demonstrably cheaper and has (on average) better outcomes. Anyone with half a brain would get behind establishing it in the US. Oh and while you are at it do something about malpractice tort reform - the major cause of excessive medical costs.