Posts by Robert Sneddon

Amazon's EYE-OF-SAURON KindlePhone will watch you with FOUR cameras - report

Re: Anyone find this kinda creepy?

Four cameras would handle 3-D gesture recognition quite well (insert obligatory reference to _bad SF movie_ here). They might not be visible-light but IR like the Kinect uses.

The "Smith" reference might be to Winston Smith, the traitorous renegade who tried to evade Big Brother's benevolent surveillance.

Thorium and inefficient solar power? That's good enough for me

India's planned thorium reactors use MEU, about 20% enriched, as a neutron source to transmute the thorium into an isotope, U-233 that will fission and release energy. The planned fuel mix also includes plutonium for an extra kick and the two non-thorium additives produce (theoretically) about 10-20% of the energy produced in a complete refuelling cycle. As far as I know the Indians have never actually built or run a thorium-based reactor, they're still a paper exercise. A few folks are working on using thorium as a fuel additive in existing PWRs and heavy-water reactors but it's still early days and there's no economic justification for using it since uranium is really cheap now and into the forseeable future.

As for the comparison between lead-acid batteries and pumped storage... Dinorwig in Wales stores about 8 GWh at full capacity, a car battery stores about 600Wh so it would take over ten million of them to match the capacity of Dinorwig. Assume a wholesale cost of about 50 quid each just for the batteries (never mind housing them, supplying the charging gear etc.) the battery array would cost about the same as Dinorwig did to build, roughly 500 million quid. Great! Except you'd have to replace all the batteries after a couple of years of operation, especially if they get deep-cycled. Dinorwig was built about forty years ago and is still going strong -- I think it costs a few million quid a year to run and there's no plans to close it as it still works fine, it's mostly concrete and pipes and water doesn't wear out.

Re: Slightly fruity comparison

The generators at Fukushima Daiichi did in fact start up OK after the earthquake knocked out the grid connections. The tsunami arrived about 30 minutes after the earthquake and the flooding knocked out the generators. The battery power reserves kept things running for a few hours after that until they were exhausted at which point the reactor cores started to overheat and the hydrogen explosions happened.

As for earthquakes, Japan IS an earthquake zone. Over 100,000 people died in the 1923 Kanto earthquake in Tokyo, over 5000 in the 90s in the one in Kobe. I've spent a couple of months total in Japan over the past few years and I've been through two noticeable earthquakes, not noticed a couple more very small ones and seen news reports of others elsewhere in the country on the TV. The earthquake in 2011 resulted in the big refinery at Chiba blowing up and spewing massive amounts of toxic smoke across large areas of eastern Tokyo but basically there are no safe places to build anything in Japan. And let's not forget taifu (typhoons) -- did you know the cause of the second-greatest loss of life in Japan in 2011 was a pair of typhoons that killed over 90 people? At the same time no-one was dying or even getting sick from radiation at and around Fukushima Daiichi.

As for the sea defences of the nuclear power stations it's worth noting that nearly every coastal city in Japan was unprepared for a tsunami of more than a couple of metres in size. That failure to anticipate a 15 metre tsunami resulted in 20,000 people dead and large areas of the country smashed. The sea defences at Fukushima Daiichi were actually of a much higher standard than the towns where people lived (and died), built to defend against a five-metre tsunami in an perceived excess of caution.

Re: Read behind the press release

The "too cheap to meter" reference was made about proposed fusion power, not fission. It was a publicity guy who said it, not an engineer or anyone who knew what they were talking about. The falsehood is too good not repeat though even though it never applied to fission.

Nuclear electricity costs about the same as coal-generated electricity. The cost of nuclear fuel is trivial, it's paying off the loans to build a reactor in the first place that brings nuclear electricity pricing up to the same level as coal generated power where digging up and moving millions of tonnes of coal each year makes up most of the final bill. Dumping the coal waste into the atmosphere is free.

Superconductors are essential in some niche applications, without them devices like NMR scanners and the like wouldn't work. We could make do with X-rays, I suppose but the fine detail and resolution NMR can produce would be lost meaning surgery would return to being a fishing expedition again. Niche but a very useful niche. There are other tasks for which superconductors are essential (Josephson junction sensors etc.) and some engineering depends on them for good performance and energy efficiency, linear motors and maglev systems like the Shanghai airport link and the proposed Japanese high-speed maglev between Tokyo and Nagoya for example.

Ramping nuclear power plants

The French ramp some of their later-generation plants since they generate 80% of their electricity from nuclear and they don't have many fossil-fuel load-following plants available to top up production otherwise. There's a problem dialling the power down in PWRs due to a buildup of a neutron absorbing fission product, Xe-135 in the fuel rods which is usually "burned" away at full-power settings but this is fixed in the newer PWR designs like the EPR1400 coupled with better operating procedures which limits the effects of the Xe-135 buildup.

Nuclear power reactors run 100% baseload wherever possible as the cost of fuel is trivial (about 0.7 US cents/kWh according to US government figures I saw a few years back) compared to the cost of operation, regulation and paying off the loans to build the plant in the first place. Generating at a 70% power level doesn't save the operators much money, refuelling tends to be done on a fixed schedule and not when the fuel rods contain a certain amount of "ash", but ramping down output means the operators earn less money than they could at full power settings.

Re: Intermittency of Solar

Smelting aluminium is not viable with intermittent energy sources. Cutting the power off and letting the melt in a electrolysis cell solidify means using jackhammers to clean it out, it won't magically spring back into life when the wind starts blowing again as the solid crust doesn't conduct electricity. Abundant hydro in Norway and geothermal generating sources in Iceland allow them to export their cheap electricity in the form of refined Al but the electrical supply has to be reliable and on-demand for the smelters to work effectively.

Re: Flywheels anyone?

Flywheels cost money to build and operate and you don't get a lot of storage for your investment. The cheapest mass energy storage system around is pumped hydro. In the UK the two big storage plants are Dinorwic in Wales and Cruachan in Scotland, holding about 8GWhr each when fully topped up. That's about half an hour of normal consumption in the UK. They cost about a billion quid each in todays money to build so reckon to spend about 100 million quid per GWh for this sort of storage, assuming you've got lots and lots of water (not something solar plants tend to have nearby given the near-desert conditions they're situated in) and good geography with high and low reservoirs separated by only a kilometre or less to reduce energy losses due to friction. They still waste about 30% of the energy produced by solar, wind and other generators in the store/resupply cycle.

Other uses for thorium

Thorium is used in small amounts in specialist welding rods and wire. Still not a mass market though.

Re: Thorium reactors and A-bombs.

The US fired a couple of U-233 devices back in the mid-50s and they worked well enough. They may not have been weaponised i.e. turned into something they could drop out of a B-52 but they had Pu-239 and U-235 to play with. I've never heard what the Soviets might have been up to with U-233 at the same time.

The proliferation problem with thorium reactors breeding U-233 is it can be chemically separated out of the fuel stream to produce pure U-233 which will work as a bomb core. Regular uranium reactor fuel starts off with a small percentage of U-235 mixed in with lots of U-238 and the spent fuel has a mixture of Pu-239 and Pu-240 in it, produced by breeding up from the U-238. Pu-239 makes good weapon cores but the presence of Pu-240 in the mix causes a lot of technical problems if someone tries this, with massive amounts of radiation and a lot of self-heating and the Pu-240 is difficult to near-impossible to separate from the good stuff next door.

Re: Intermittency of Solar

Actually modern GenIII nukes can ramp up and down quite quickly, from 100% power to 70% power in about 15 minutes and about the same time to go back to 100% power. Older reactors can't do this easily for various reasons.

Big fuck-off weight... let's say ten tonnes, the sort of weight a beefy and expensive crane can handle so you'll be spending a few thousand quid at least to build it plus its cabling, support structure, generator/motor system, safety gear etc. into the block of flats. Raise it 10 metres, that's about the height of a three story block of flats. Potential energy is m x g x h where g is gravitational acceleration, about 10 m/s/s so that ten tonne block raised ten metres will hold a total of 1 megajoule! Wow! All that energy! That's a kilowatt over... a thousand seconds... ummm... 20 minutes... is that all?

Re: Thorium reactors

No, they didn't. By the time nuclear power reactors started to be mass-produced in the mid-60s all of the big powers who wanted nuclear weapons had made as much plutonium-239 as they needed in purpose-built reactors like the one at Windscale that caught fire or the ones in Hanford in the US etc. There were attempts to build reactors that could produce weapons-grade plutonium like the British Magnox and the Soviet RMBK-4 but they were not needed for that purpose by the time they were actually getting built.

Modern PWRs and BWRs have some plutonium in their spent fuel at the end of an operating cycle but it's a mixture of Pu-239 and Pu-240 which is pretty much useless for weapons which need high-purity Pu-239 to work well if at all and the Pu-239 can't be separated out easily -- it's actually a lot simpler to separate U-235 from U-238 if someone wants bomb-grade material and that's difficult enough.

Re: Thorium reactors

Uranium is plentiful at least for the next few decades and cheap right now so the price of fuel is a minor part of the cost of generating electricity in existing reactors. It is possible to use thorium in existing PWR designs but they need lots more neutrons to convert the thorium into uranium-233 which can then be fissioned to produce energy. In a regular reactor uranium-235 is fissioned without that breeding step so they don't need a high neutron flux to run. The planned Indian thorium reactors are designed to use medium-enriched uranium-235 and plutonium-239/240 in the fuel mix to provide the extra neutron flux needed to breed the Th-232 up into U-233; this will have knock-on effects on the reactor structures, the radio-chemistry of the fuel pellets etc. and could lead to unforeseen consequences in a decade or two.

There have been attempts to use thorium in pebble-bed reactors but they've not been a great success as the pebbles fracture, spall, shed dust, jam the mechanism etc. I think the German pebble-bed reactor that was shut down in 1985 for these reasons is still waiting for someone to come up with a way to decommission it. Basically if you see proposals for a reactor that moves the fuel around while it's running you're looking at something which can go badly wrong with very problematic consequences.

Microsoft to execs: Please don't leave us. Here, have some shares

Re: Augean Stables?

MS wrote off $6.3 billion about a year ago, the aQuantive acquisition that went nowhere but hardly anyone in the tech biz noticed. The acknowledged losses of the Surface RT are small change compared to that. As for the financial results, MSFT 2013 yearly figures released in July were up several percent over the previous year in revenues and profits, probably because the Surface RT writedown this year wasn't as brutal as the aQuantive writedown...

US gov preps sale of TOP SECRET disease research island

Ookunoshima island in Japan was the home of the Japanese chemical warfare business up to and during WWII. It's now a tourist attraction with a Poison Gas Museum and a cute rabbit mascot to attract visitors. Maybe the buyers can turn Plum Island into a tourist attraction too.

Google cripples Chromecast third party replay

Re: Would you buy...

Actually buying a Chromecast is like buying a razor-blade handle, it's incredibly cheap but the maker expects you to keep on buying expensive blades that only fit that handle for ever and ever. Making your own blades or buying cheap Hong Kong knockoffs is not part of their marketing plan.

Old Smelly 'cause he doesn't have Gillette moments.

Amazon spaffs MYSTERY private Wi-Fi waves all over Apple's orchard

Re: 802.11b/g/n is being replaced

There are very few users of 802.11ac at the moment. Once it becomes popular with more users demanding higher-speed traffic it will suffer the same problems as b/g/n is suffering from today and 802.11a (which also occupies part of the 5GHz spectrum) is starting to experience. Enjoy the wide-open spaces while you can.

Oh noes! New 'CRISIS DISASTER' at Fukushima! Oh wait, it's nothing. Again

Re: Stop downplaying it

Actually a lot of people evacuated after the tsunami and during the reactor meltdowns have returned home to the area around the plant. It's not a disaster so you haven't heard about their return in the news. The Japanese government recently finished reassessing the contamination levels and have opened more areas to the public again. The big worry of contamination shifting due to weather, rainfall, wind etc. has mostly gone away after thirty months, the areas that are still significantly contaminated won't change much and are still out of bounds.

Nobody's building older GenII plants, the sort that blew up at Fukushima due to overheating. The improvements you want have already been developed to the point where new reactors are expected to have a working life of at least sixty years minimum. What gets in the way of them being built is the high capital up-front cost and the fact existing reactors from the 70s and 80s are actually in very good condition, in part because they were overbuilt in the first place and after regular inspections they are often being given licence extensions to operate for another few years and this has reduced the demand for new construction. At the same time gas is cheap, coal is abundant and nobody cares much about CO2 levels and air pollution.

Windows NT: Remember Microsoft's almost perfect 20-year-old?

Re: Booting up

I put NT4 Workstation on a dual-PPro box doing graphics work for a printing firm. It was pretty stable as I recall. We had specified a Matrox Millenium for the graphics card, it wasn't fast but the video drivers were solid and well-supported.

The only thing that would blue-screen it reliably was our attempt(s) to install an early version of Open Office -- the installation process would attempt to overlay its own windowing manager on top of the Windows one then crash out. We did get other blue screens occasionally when our main application, Corel Draw went boink on us after doing nasty things to the 256MB of memory this monster was populated with but saving early and often meant it didn't affect us much. Corel Draw did that two-step release thing, step 1 would introduce a lot of new features along with new bugs and the next release fixed most of the bugs. A lot of the bugs caused blue screens from memory allocation faults.

Today I can reboot my current Win8 desktop after a power cut and have it come back up where I left it. Progress, eh?

Microsoft warns of post-April zero day hack bonanza on Windows XP

Re: Simplest solution to XP diehards

XP Home/Pro is a 32-bit OS with a hard RAM limit of about 3.5GB and it doesn't support drive volumes bigger than 2TB. For gamers the limit for XP is DirectX 9. Win 7 and Win 8 don't suffer from those limitations.

I've got a couple of boxes at home here still running XP but they're not connected to the internet when I do run them up which isn't very often (basically backwards compatibility testing and playing some older games).

AREA 51 - THE TRUTH by the CIA: Official dossier blows lid off US secrets

Re: Astonishingly lovely but just a little bit threatening to look at.

Ah, the old "Mysteries of the Ancients" line makes its appearance again...

The U-2 is basically a high-altitude glider and, as the Gary Powers incident proved, vulnerable to getting shot down quite easily even fifty years ago when flying and spying over somebody else's territory. A modern version would be much better than the drafting-parchment and sliderule designers could manage back then, never mind the refinements in engine technology and construction materials available to today's manufacturers but nobody would bother building one for the purpose of espionage simply because it is so vulnerable.

As for the SR-71 it was a logistical nightmare to operate with major range limitations; sure it could go fast and fly high but it was a fuel hog at the best of times and in high-speed dash mode it would run out of fuel very quickly. A 12-hour mission required a fleet of as many as eight specialised tankers orbiting in safe air outside the target country's 200-mile limit and the range limitations meant the SR-71 couldn't penetrate too far in from the coast before it would have to turn back to safe air to tanker up again. Satellites could see everything below them on every pass in multispectral mode and with the advent of electronic sensors in more detail than any camera a plane could carry and use and without the political implications of another Gary Powers incident, something that was always a risk with the SR-71 spy flights.

Shareholders hoping to squeeze cash from Kodak are deluded, says court

The pension scheme for Kodak workers is probably worth robbing, it's been done to other companies that folded as it's usually the last substantial asset left standing after the top knobs have taken their golden parachute bonuses for driving the company into extinction so competently (see the US Hostess corporation for a recent example). The Kodak shareholders group and their advocati* were probably hoping the judge would let them get at the pension fund with the long knives and fuck the retirees. Good on the judge (for once).

*Advocati -- an oily bottom-feeding scum-sucking fish with no backbone.

Canonical: Last change to Ubuntu Edge phone price – we promise

Re: Some day... who knows?

So how many hours a week do you expect to spend tweaking your "nearly working once I install the latest patches" phone? Fact is, 99.99% of phone users want a phone that will make and receive calls and play Angry Birds. A few (a very few) folks like your good self want a box-of-LEGOs toy they can play with endlessly and whether it can actually do what it's supposed to at any given time is irrelevant to you. Mr. Shuttleworth is willing to provide you with just such a toy as long as you send him money right now and then wait a few months to see if he'll actually come through with what he's promised you. Me, if I needed another phone I'd go along the street to one of the local phone emporia and get something off-the-shelf that works as a phone and I'd pay a lot less than the Ubuntuphone is going to cost.

Qualcomm exec on eight-core mobile chips: They're 'dumb'

Re: I agree. 8 core phones are pretty dumb.

How much RAM is in your smartphone? How much cache do the CPU cores have access to? If you want to rock a desktop OS like gangbusters then lots of RAM and a good helping of cache will really speed things up, and those are noticeably lacking in all the smartphone and most tablet designs I've seen. Lessee, the iPhone 5 has 1GB of RAM, not sure how much CPU cache. Androids like the Galaxy S4 have 2GB RAM so its a bit better but still quite anaemic by modern desktop OS standards. About the only affordable tablet that looks like its ready for real work on a desktop is the MS Surface Pro with an i5 CPU (3MB of cache) and 4GB of RAM, but then again it's not a phone.

Frankly it would be better for you to keep your phone in your pocket and rock a real desktop machine like gangbusters instead. Besides what would you do if you got to the office and found you'd left your phone at home?

SPEARS joins the 19-mile-high club: Intimate snaps

Model M?

Train spotters, bus spotters, Model M spotters... the four monitors together in the first picture aren't as old as the keyboard underneath them.

Lenovo ThinkPad Helix Ultrabook: Your new summer convertible?

Comparison with Apple

Worth noting the Helix comes with a 3-year warranty, no extra moolah required unlike the extra-cost Applecare options for extended coverage on their kit. I had a look at the Lenovo website but it wasn't clear what the warranty on offer actually entails, it just says "3 Year Depot/Express Warranty", what that actually means I don't know as the website seems to be rather coy on the subject.

Microsoft's earnings down on slow Windows sales, Surface RT bust

No change

The numbers MS released yesterday aren't much different to the previous quarter and year, up a bit if anything, and until the revenue and earnings figures go seriously and consistently down then Steve's job is safe.

Financial analysts are not much better than the woad-covered druids who haruspexed chickens to figure out who was going to win the next big fight the tribe was getting set for.

Boeing batteries back under spotlight as 787 burns at Heathrow

No rear rest area

It's being reported that the Etihad 787s aren't configured with a flight attendant bunkroom in the roofspace; it's an option for aircraft that are expected to do 10-hour-plus long-haul and need two FA crews on board and Etihad doesn't fly that sort of route. The scorched hull area is above the galley, however and there may be wiring runs in that area -- the APU is positioned under the tailplane.

European Space Agency goes for mostly solid Ariane 6

Re: Full spectrum dominance

The main commercial market for GEO satellites is direct-broadcast and that's still big business especially in places like India and the Pacific where fibre to the home isn't really practical or cost-effective. The bigger the satellite the more transponders it can carry, the more manoeuvering fuel it can start with, more redundancy of components, larger solar arrays etc. etc. Intelsat-20, the heaviest GEO bird ever launched (along with a smaller GEO satellite by an Ariane 5 last August) has three tonnes of fuel on board and it is expected to operate for 15 years. It replaces two other satellites positioned to the south of India and covering large chunks of east Africa, central Russia, Indonesia, Korea and at the edge of its coverage it can transmit to Japan. If you've got a decent-sized steerable dish and are in the UK it's possible you might be able to pick up a signal from one if its transponders pointed at the Middle East.

Full spectrum cominance

The Ariane 6 seems to be aimed at replacing the Soyuz spacecraft that ESA are currently operating from Kourou. They've got the Vega solid-fuel launcher (aka Berlusconi's Bottle Rocket) for small scientific payloads up to about 3 tonnes into LEO, the Soyuz for anything up to 8 tonnes or so and the full-fig Ariane V for the dual-GEO comms launches and Big Jobs like the ISS ATV cargoship (20 tonnes total into LEO). That gives them a full-spectrum launch capability that's not dependent on the Soviet^Russian Soyuz which is getting a bit long in the tooth. I don't know, for example, if the licencing agreement would allow ESA to fly military or intelligence payloads on Soyuz vehicles.

The only weirdness I can see is the intended use of the fully-cryogenic Da Vinci upper stage on the Ariane 6 as that adds expensive launchpad fuel handling problems that were mostly negated by the move to solids. A storable-propellant (N2O4/UDMH) upper stage would have been a better bet, methinks although probably giving less delta-V per tonne for payload insertions than LOX/LH2.

The Ariane 5 ME will continue to fly after (and if ever) the Ariane 6 starts taking GEO orders from its big sister. The comms people are designing bigger and bigger birds (Intelsat-20 was about 6 tonnes, too big for Falcon 9 v1.1 to launch into GTO) and at the moment the Ariane 5 has that market sewn up.

US Navy coughs $34.5m for hyper-kill railgun that DOESN'T self-destruct

Bullet speeds

Typical sniper bullets like the .338 Lapua Magnum have a muzzle velocity of about 880 m/s so a bullet travelling over a distance of 2km will take over three seconds to reach its target allowing air resistance -- by the time the bullet has gone 300 metres it's already lost 130m/s according to the ballistics charts I've read.

Air friction and Battleships

Straightline flight of a railgun projectile at sea-level (well it is being fired from a ship) will result in a cloud of molten metal a couple of clicks from the railgun's muzzle. The projectile is already bloody hot from the millions of amps passed through it as it accelerates between the rails, the air friction from travelling at Mach 7 would finish the job. Even if by some miracle it did survive it would lose a lot of its velocity due to the aforementioned air friction so it would still take a lot more than 2 minutes to go 200 kilometres.

The battleship solution is to fire a shell from a gun in a high parabolic arc so most of its trajectory is in thin air and it will retain most of its initial speed and not melt or overheat on the way. That takes even longer to get to target, of course; a 15" shell from a British WWII battleship could take 90 seconds to cover 30 kilometres with a muzzle velocity of about 750 m/s, just over Mach 2. Firing railgun projectiles in the same high ballistic arc would double or triple their time-to-target.

Like battleship shells railgun projectiles don't have terminal guidance so with wind drift, irregularities in the firing system etc. the circular error at the target 200 km away would probably be a few hundred metres. If the target is a vehicle like a tank it may not even be in the same country when the projectile arrives. If the aim is to hit a stationary building or structure then it's rare that it has to be destroyed right now and a Tomahawk or two will do the job nicely -- see the Chinese Embassy in Belgrade in the recent past to show just how precise that sort of targetting can be done.

Railguns might, just might be useful for close-in defence of major warships, able to hit to a line-of-sight threat before it comes in too close but scaling them down to something the size of a Phalanx is not going to be easy.

3-2-1... BOOM: Russian rocket launches, explodes into TOXIC FIREBALL

Re: mass driver

By "orders of magnitude" you mean about 60% less at 7 to 8km -- the air pressure at the top of Everest (9km plus) is about 35% of sea level. An SR-71 flying at about 3000 kph at 25km altitude is glowing a dull red from air friction even with the fuel being used to cool the skin before it gets pumped into the engines. A capsule from a mass driver travelling at ten times that speed (drag goes up as the cube of speed so a thousand times more heating effect than the modest 600 deg C temperature rise the SR-71 experiences) would be vapourised before it got anywhere near orbit.

Re: Oops

The Delta 4 Heavy can lift about 24 tonnes into LEO, 3 tonnes more than the Proton-M and its even cleaner than the Atlas as its fully cryogenic with no solid boosters. The Ariane V lifts about the same mass as the Proton-M but it uses solids to get it off the pad. The next Falcon 9 to fly is the uprated stretch version (v1.1) and it's only capable of 15-16 tonnes into LEO. It's also about 6 months behind schedule with the first flight now due in September.

Apple's new data center to be solar powered, 100% green

Swings and roundabouts

The Chocolate Factory is building a solar power station which will connect into Nevada's grid and generate a variable amount of electricity when the sun shines. The total amount generated each year and pumped into the grid will match or exceed what they pull out of the grid 24/7/365 to power their data centre, assuming the design and operation works out. The power station isn't being built to provide electricity just for the data centre.

Live or let dial - phones ain’t what they used to be

User Experience

It was the heavy steel frame inside the casing that gave rotary-dial handsets their weight, and they needed it since they had to stay still on the table or desk while you turned the dial to make calls. It's the same reason IBM Model M keyboards have a heavy steel plate in their base so they don't slide around as you type. The ability to crush a spammer's skull with one is a bonus.

Missed my chance

One of the local charity shops recently had a genuine nuclear-powered WMD rotary-dial Trimphone in the window. "I'll have that when I get back from the supermarket." I said to myself but it was gone by then. Damn.

Curtain drops on Apple Store ahead of WWDC: What lies behind?

Multimonitor and HDMI

I notice the new desktop Mac Pro, although it can be configured with dual GPUs only has a single HDMI port and no higher-spec DisplayPort. That means running multiple monitors can only be achieved through the Thunderbolt ports and who's the only (pricey) manufacturer of a TB-capable monitor...? Let me think...

Boffins develop 'practically free' sulphur-powered batteries

Re: Lucas Electric Vehicles,1980s called, your sodium-sulphur battery experience is needed

Sodium-sulphur batteries are being used as stationary power storage but they have a nasty habit of catching fire at which point lots of burning sodium and sulphur means they take a lot of putting out -- the fire in a 1MWh Na-S battery at the NGK offices in Japan took two weeks to extinguish.

http://www.ngk.co.jp/english/news/2011/1007.html

ESA retires Herschel space telescope as too hot to handle

Re: Dual use

It's the biggest mirror outside the atmosphere[1] by a long way, as far as I can recall which gives it an advantage in the infra-red imaging spectrum, and it actually got built and launched and used. The JWST seems to have grown roots and its launch and commissioning is receding deep into the future almost as fast as the universe is expanding...

I'm envisaging the Herschel could have carried an additional lower-resolution detector operating in the near IR, cooled by a heat-pump and used for recording time-series IR data of dynamic changes in nebulae etc. over a period of years or even (if the money and hardware held out) decades. The Hubble has been kept running for nearly thirty years now after a lot of teething-trouble TLC and it still has a few more years left under the hood so I'd expect the Herschel's "bus" with its more modern hardware to be able to match that to support an extended scientific program if the detectors were available.

[1] I think there's a radiotelescope satellite that's got a bigger collecting dish but it's not optical.

Dual use

It's a shame there wasn't another instrument on board that could make use of that ginormous mirror now the primary mission is complete.

German boffins aim to burn natural gas - WITHOUT CO2 emissions

Re: Like a lava lamp for people with X ray vision

Pumping room-temperature gas into a column of molten metal at several hundred degrees C is going to cool it down significantly, requiring more external energy to be injected to keep it operating. The more gas injected, the more energy needed to keep the column from cooling down and solidifying.

Is the decomposition reaction endo- or exothermic? If it's exothermic then it's possible some of this cooling effect can be alleviated but I suspect TANSTAAFL applies.

Global warming fingered as Superstorm Sandy supersizer

Re: Scientific Terminology

"Lessee, did I forget anything?"

Don't buy a house in a development called "The Water Meadows".

New nuke could POWER WORLD UNTIL 2083

Flash-boiling

The Three Mile Island and the Fukushima reactor explosions were not due to "flash-boiling" overpressure they were due to a high-temperature catalytic reaction involving the fuel rod cladding material, zirconium decomposing steam into hydrogen and oxygen which then recombined violently. Flash-boiling happens all the time in Boiling Water Reactors (BWRs) where water flashes into steam as it is sprayed onto hot fuel rods inside the reactor vessel.

Re: connected to a drain plug of salt that has been frozen solid

I visited Fukushima City last year. It's about 60km NW from the Fukushima Daiichi plant on the coast, in line with one of the contamination plumes. It's got a higher background count than it did before the explosions and releases but it's not been evacuated. If I spent a year there I'd have picked up about 8-10 mSv of exposure or about 10% of the annual permitted dosage of a nuclear industry worker.

Re: low carbon energy source?

Germany has a carbon footprint of about 10 tonnes per person per year despite (or possibly because of) their dash for renewables backed by burning fossil carbon in the form of Russian natural gas as well as the hundreds of millions of tonnes of lignite and hard coal they burn each year to keep the lights on. France which generates 80% of its electricity from nuclear power stations has a carbon footprint of 5 tonnes per person per year, and has done so for about thirty years now since most of their reactor fleet came on stream in the mid-80s.

Re: Even if it does generate Pu

Depleted uranium isn't particularly toxic either in its metal form (or oxide if it's the result of a DU weapon hitting an armoured vehicle and lighting off). Most uranium compounds are not absorbed easily by the body and excreted (if ingested or inhaled) quite soon after exposure. Same for plutonium although it is a bit more biologically reactive than uranium. The radiotoxicity of uranium generally (U-235 and U-238 which makes up nearly all of the uranium around) is very low; the raw ores which include billions of years of decay products are a lot more radioactive than refined metal and oxide-form fuel pellets. Pu isotopes are a lot more radioactive with shorter half-lifes and hence more radiologically dangerous if ingested or inhaled but again they don't tend to linger.

After WWII when uranium and plutonium became strategic materials being processed in tonne quantities in factories and enrichment plants a lot of research was done on their effects on the human body as contamination, ingestion, inhalation etc. were going to happen. The experimental results were as I described above, not much basically. There are a lot of other metals which are a lot more dangerous and biologically active such as arsenic, cadmium, beryllium, lead etc.

Microsoft Surface Pro will land in UK in WEEKS*

Re: An injection moulded magnesium chassis?

Never worked with magnesium, have you? It shows, rather.

There's this little thing called heat conduction -- magnesium is particularly good at it. Applying a mere thousand degree flame with a few watts of energy to a spot on a piece of solid magnesium will damage the surface but it will not cause the magnesium to undergo rapid oxidation (or to use the simpler word, "burn") since the energy is rapidly dissipated.

Igniting solid magnesium requires a lot of energy -- an acetylene torch running oxygen-rich might work on a Surface Pro's casing but not much less, a few kW of heat on a square cm or so. Magnesium alloy aircraft wheels required a bonfire before they'd go off as I've been told by friends who have experimented in that direction. A pure oxygen atmosphere would help too.

Turn the magnesium into shavings or fine powder and you've got more chance of lighting it off with a low-energy source like a cigarette lighter but then again aluminium will do the same thing, it's why Al powder is used in solid rocket engines.