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Comment Re:Math Doesn't Add Up (Score 1) 144

Combined-cycle gas turbines (CCGTs) can reach 60% efficiency but they're more complicated than a simple once-through gas turbine of the sort that's likely to be fitted to a truck like this. CCGT power plants boil water to steam with the turbine exhaust and use a secondary steam turbine to generate more electricity hence the 60% figure but they are bigger, heavier and more complex than any conceivable mobile power plant.

Comment Re:Math doesn't work out (Score 1) 1023

Some Lidl stores do have self-checkouts. I was in one today and used a self-checkout there. However the Lidl store I go to most often doesn't have self checkouts and I can spend more time waiting in the queue for a manual checkout than I did shopping for the half-dozen or so items I usually buy. The till operators are pretty quick but there are never enough of them on duty to save on overheads and the store is always busy because of the low prices.

Comment Numbers (Score 1) 324

A thousand tonne train of railcars pulled up a slope 100 metres in height, assuming no losses (spherical cow assumptions here but bear with me) will require Mass x Gravity x Height = 1 billion joules = 270 kWhr which at commercial rates for electricity is worth maybe $20 or $30 US. That's not a lot of energy storage given the capital cost of track and equipment and recurring maintenance costs etc.

Comment Re:We know what the next innovation is. (Score 1) 225

The big problem with iCar is that obeying the Holy Jobs design rules there will be no holes in the bodyshell large enough for people to get in and out. The solution (so to speak) to this will be the iChipper(tm) with a flexible hose and a unique patented nozzle coupling in the side of the iCar. It will require an up-to-date version of iTunes to get back out of iCar.

Comment Re:May not continue for the long-term (Score 1) 314

Solar thermal involves storing heat in something like a molten salt tank and releasing that heat later to generate electricity when the sun is down. This wastes energy -- direct use of the heat would produce more electricity in total over a day cycle but peaking over a shorter period of time.

Most of the solar thermal plants that have been constructed to date use thousands of heliostat mirrors to concentrated light on a tower-mounted heat store. The tower has to be very strong to carry the mass of the heat store and the heliostats move in both X and Y to track the sun, eating energy and breaking down. Simpler non-storing solar thermal plants are cheaper to build and operate, typically using fixed mirror troughs and heat transfer pipes to collect heat for steam turbines.

As for moving to 100% electric cars, nations that do so will need electricity to charge them and that's probably why China and India are building lots more coal-fired power stations. Assuming they can source coal locally or at low cost from places like Australia it saves them buying as much oil as they do today so it's a win-win. The new coal plants will probably have modern stack filtration so they won't be quite as toxic as the old plants but they'll still not be very "green" and of course they will emit large amounts of fossil-fuel-derived CO2.

Comment Re:Lee Se-dol also learns (Score 1) 109

There are only a few hundred records of games played by Lee Sedol and only a few dozen of them were championship games lasting several hours or even a couple of days like the AlphaGo series. The playing style of these longer games is different to the shorter games played against lower-ranked players or for tuition or study.

The DeepMind people have stated clearly that AlphaGo has NOT been prepped with games by Lee Sedol. I don't know if the reverse is true but it's common for Go players facing a particular opponent, especially in a series, to study some or all of their game records.

Comment Re:Terrorist Disables Mobile Phones On Chicago Bus (Score 2) 518

I work alongside someone who has permission to keep his mobile phone on his desk in an office which is otherwise meant to be a no-mobile zone. He's waiting for a transplant and if an organ match comes available he needs to know right away so he can get to the hospital and start getting prepped for the operation immediately. Someone using a jammer for their convenience could result in him dying before he can get treated.

Comment Re:Obligatory.. (Score 1) 90

One of the weapon systems in the US military Bag of Holding drops strings of conductive carbon fibres over electrical switching stations and generating plants to blow them out. It was used during the initial attack on Iraq in 2003, deployed by cruise missiles IIRC. There may also be a precision free-fall bomb that can do the same thing.

Comment Re:32inch 4K monitors not ready for prime time yet (Score 1) 156

I've been using a Dell 32" 4k display for about 15 months now, running it at 60Hz over DisplayPort from a budget AMD video card, the cheapest I could buy at the time that had DP output. I don't game on this monitor, other than Spider and the occasional sudoku puzzle.

I used the DP cable supplied by Dell with the montor (UP3214Q) and it's worked perfectly although it took a little time to set it up and get it to run at 60Hz since it defaulted to 30Hz out of the box for compatibility reasons. No backlight bleed that I can see.

Comment Re:Multiple heads (Score 4, Informative) 202

There were SCSI drives with four head actuators, one in each corner of the drive casing. They were treated as four separate drives logically and used to speed up reads on a "first to deliver the requested block" basis. They were horrendously expensive and it turned out to be very difficult to optimise the read process to gain the desired perfomance boost.

Comment Re:Langley (Score 1) 53

The light from the two scopes has to be combined optically though. The phase information is crucial (the two mirrors have to be aligned to a fraction of a wavelength of light).

That's not totally correct; if the processing system knows what the alignment error is at any time it can correct the image data collected, it doesn't have to have the mirrors in "perfect" mechanical alignment at all times. It's not a trivial thing to do but it's feasible. It recovers resolution at the expense of light grasp and that is a tradeoff that might be worth paying in some cases.

Comment Re:Langley (Score 3, Interesting) 53

One problem with the large-mirror spy satellites is that they can only look at one place on the ground in detail in a single pass since they only carry one large mirror. I suspect modern spy satellites carry multiple independently-targettable imaging systems with the ability to digitally combine images for higher resolution where needed on a case-by-case basis. This is similar to the way the largest land-based astronomical telescopes are now all multiple-mirror designs but without the requirement for on-the-fly reconfiguration during observation campaigns.

Comment Re:Utter Stupidity (Score 4, Interesting) 143

Gas and coal are cheap and the waste from burning them can be dumped into the atmosphere and nobody cares enough to stop burning them since that would increase the price of electricity and cost jobs (see "War on Coal"). Nuclear reactors, including breeders are expensive to build and everyone is petrified of spent fuel from reactors because they've been fed bullshit and crappy movies about the effects of radiation ever since 1945.

Using up spent fuel in new-design reactors by reprocessing and other means will cost money and new uranium fuel is really cheap at the moment (current spot price for U3O8 yellowcake is $34.15 per lb) and it will remain cheap for another 50 years and more as more mining sources are developed and brought into production.

The Russian BN-800 reactor is designed to burn spent fuel and also plutonium from decommissioned nuclear weapons but it's quite experimental and it will be a while before more reactors like it are built. The fuel for it still needs to be processed and specially fabricated, it can't just take used fuel pellets and this adds to the expected cost of operations.

Some countries such as Russia do reprocess spent fuel but that only concentrates the unusable isotopes that are actually waste and they still need to be dealt with, probably by deep geological burial. There doesn't seem to be any real problem with this idea but it gets a lot of attention from the panic merchants with the 100,000 year figure being thrown about a lot although that's quite arbitrary considering the environmental radiation sources already present around us naturally which do not emanate from the nuclear power industry.

Comment Re:High vs Low (Score 2) 339

because the fast neutrons eventually destroy every known material used as the plasma-facing "first" wall. That's something the ITER fanboys are not telling you (for obvious reasons).

That's weird, I've been aware for a decade or more now that ITER is working on assorted possible first-wall technologies and the JET in Culham, England is being repurposed as a wall material testbed. Maybe they didn't tell you but they've been telling everyone else.

The walls are going to be sacrificial, needing to be replaced using remote handling equipment. It's part of the "E" in the acronym "ITER", standing for "Experimental". Lithium, converted into tritiurm and deuterium by neutron bombardment is one possibility for walls as its product is a fuel source for further fusion. Other tougher materials might last longer, possibly decades or more before needing replacement though. ITER is a testbed for such research.

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