Slashdot Mirror


User: brambus

brambus's activity in the archive.

Stories
0
Comments
403
First seen
Last seen
Profile
(view on slashdot.org)

Comments · 403

  1. Re:My daugher had 33 MBq injected last week on One Trillion Bq Released By Nuclear Debris Removal At Fukushima So Far · · Score: 1

    Still, they have managed to make a mess with plenty of actinides, strontium-99 and caesium-133 all over the place which was emphatically *not* meant to happen.

    Well, no argument about whether the power plant was improperly sited (it clearly was) or improperly managed (it clearly was), but I'd hold off on the amount of radiation released as being "a mess" that the Japanese cleanup operation had much to do with. I ran a quick set of calculations on the numbers in this article and assuming all of the release was cesium (which it unfortunately didn't say), I estimated they released only about 340mg of Cs-137 in this cleanup operation (about 0.64ml by volume). I challenge you to find a cleanup operation that can track all pieces down to the last gram of material. That it is not to say that they shouldn't try to do better - clearly they should - but I'm not prepared to lay blame on them for not getting an extremely hard job done to ideal conditions. If the bulk of the material was Tritium, as you say, then it's even less volume/mass than this.

    And as for Tritium, at a density of ~0.27kg/m^3 (kinda comparable to helium's 0.18kg/m^3 and much below air's 1.275kg/m^3), I'd say it's not a big deal since it'll just float up in the atmosphere and probably escape to space, *unless* it burns and forms T2O molecules which would sink down towards the ground and possibly get bioabsorbed. Hydrogen has an auto-ignition temperature of ~500C, so I wouldn't really worry about that happening, but maybe I'm making a mistake somewhere. If you have more data, can you comment on my analysis?

  2. Re:My daugher had 33 MBq injected last week on One Trillion Bq Released By Nuclear Debris Removal At Fukushima So Far · · Score: 1

    33MBq of what? If it's Tc99m, then it's gone from her system in ~3 days while emitting a total of ~1 trillion 140 keV gamma photons. Now consider the following horror: your body contains ~5kBq of radioactive Potassium-40, where each decay produces betas (90%) and gammas (10%) of 10x the energy for your entire lifetime! Oh noes! So how much is that in about 80 years? About 10 trillion events, but at 10x the energy, so about 100x more energy dumped, not to speak of that beta radiation has a much shorter mean free path than gammas, so the impact is about 500-1000x worse than that of the "useless" medical procedure. And now consider that this isn't the only source of background radiation affecting your body (just the majority source of internal emitters).

    Honestly, calm down and enjoy life. Big numbers without context don't mean anything.

  3. Re:Que surprise? on Lawrence Krauss: Congress Is Trying To Defund Scientists At Energy Department · · Score: 1

    Our politicians are a bunch of pork-minded, short-sighted luddite political hacks more concerned with their privileges than with doing what's best for the American public?

    John Oliver nailed it.

  4. Once again, resource shortages come down to energy on Western US States Using Up Ground Water At an Alarming Rate · · Score: 1

    There's plenty of water on this planet, more than we could ever hope for, the only trouble is, it needs expensive desalinization, which ultimately comes down to having the energy available to perform the process. We have the technologies to do it more cheaply, but we're choosing not to use them - high temperature nuclear reactors can desalinate water by using waste heat from the reactor and end this water problem once and for all. I wonder if our future descendants will look at us with as much pity as we do at the first cave men who were struggling with mastering fire.

  5. Re:More inconvienient than the average filter. on UK Users Overwhelmingly Spurn Broadband Filters · · Score: 1
    Way to equivocate google images being used for classwork by kids with school-sponsored use for non-educational purposes (assembly). Also, many of the cases you cite would constitute fair use, but due to the corrupt system we have they're not challenged, you just tuck your tail in and run.

    Hell, some of the largest companies are getting sued for using a photograph from the Internet without permission in their advertising etc. - this is a symptom of people NOT being taught about copyright law when they are in school

    Indeed, for example you apparently weren't educated on the difference between "educational non-profit" and "commercial for-profit" use; the latter clearly not being fair use and being something I argued for.

    I'm stopping your kid's school getting sued for 10 x damages for wilfull infringement of copyright and having to pay thousands that would be better spent on, say, computers or properly licensed software or books or teachers

    Could you please, I don't know, save that money on the shitty commercial software to police their thoughts over the net and instead get to educating them about the value of open-source, sharing and open collaboration? Just a thought.

  6. Re:More inconvienient than the average filter. on UK Users Overwhelmingly Spurn Broadband Filters · · Score: 1

    1) I said "educational non-profit" - do you think there's a reason I used these two words together?

    2) I'm well aware that there are other considerations for fair use (which is why linked to the page), one of them being impact on the market value of a work.

    You can't honestly claim that a kid taking an image from google in order to use in their class work violates this. Sure there are cases in a school setting where using an image wouldn't constitute fair use, but are you seriously arguing for throwing the baby out with the bathwater? (i.e. for a few asshats we'll just destroy the value of the resource for everybody)

  7. Re:Very far from practical application on MIT Combines Carbon Foam and Graphite Flakes For Efficient Solar Steam Generati · · Score: 1

    1) You're confusing your home water heating with a power steam generator. 2) Exactly, the foam is nothing but a heat exchanger. What exactly does this do that a heat exchanger doesn't? Look, fundamentally what they've got here is just a highly porous black body. They use the blackness to absorb lots of solar radiation energy and use its porousness to transfer heat to a working fluid. Neat, but not really such a revolution. As for hexane as a working fluid: not sure a highly flammable gas with a flash point of -26C being moved through a gas turbine under high temperature and pressure is such a great idea. There's probably a reason why we tend to use inert working fluids in these things.

  8. Re:More inconvienient than the average filter. on UK Users Overwhelmingly Spurn Broadband Filters · · Score: 2, Insightful

    Last I checked, there's that thing called fair use that actually allows educational non-profit use of copyrighted works, so you can get off your moral high horse.

    >"Virtually impossible" to use the school's computers for schoolwork? How did we live before Google Images?

    I also attended school without Internet access, but damn it's a valuable educational resource to have and it wouldn't cross my mind to demolish that resource simply to protect my prudish and backwards sense of morality (assuming I had one). In short: move over grandpa.

  9. Very far from practical application on MIT Combines Carbon Foam and Graphite Flakes For Efficient Solar Steam Generati · · Score: 2
    This is all neat, but it's very far from practical application. What they've created is essentially just a very dark lump of porous carbon that can draw in water and exchange heat with it. Interesting, but not revolutionary by any means. Most important questions still remain:
    • What's the production cost of this material?
    • What are the scaling properties? (Presumably, since we're talking about surface heating here, pretty limited.)
    • What's the longevity of the material under non-stop usage?
    • What's the steam outlet temperature and pressure from a system like this? If it's 100C and ~1atm, then just install solar PV or CSP.
  10. > the inefficiencies of steam-powered power-plants are in the moving parts of the rankine cycle

    No, the inefficiencies of the Rankine cycle come from fundamental laws of thermodynamics and are inherent to all heat engines.

  11. Re:Carbon impact is misleading on Japan To Offer $20,000 Subsidy For Fuel-Cell Cars · · Score: 1

    You forgot one ingredient of electrolysis (hint: it's in the name) and guess where that comes from.

  12. Re:WTF? on Germany's Glut of Electricity Causing Prices To Plummet · · Score: 1

    Thanks for the kind words, though I must confess I'm also just an "armchair expert". The difference is I'm trained as an engineer, have studied electrical engineering and wasn't afraid to check the math on the political talking points. And although I wish it did, it simply doesn't add up.

  13. Re:Intermittancy on Researchers Claim Wind Turbine Energy Payback In Less Than a Year · · Score: 1

    You should calm down a bit and educate yourself on wind production stability a bit: http://www.gridwatch.templar.c...

    The UK has better than 10GW of installed on-shore and off-shore wind over a geographical area >1000 km across and yet over the latter half of the month of June overall average production was

    You trash engineers as too stupid when they tell you this is a serious unresolved problem, but then call on them to find a solution? Have you ever considered the possibility that the grid engineers have a bit more knowledge on the subject than you and so they understand the magnitude of the problems better? Of course not, because they're all in cahoots with "big coal" or whatever anti-corporatist conspiracy theory floats in the blogosphere this week.

  14. Re:WTF? on Germany's Glut of Electricity Causing Prices To Plummet · · Score: 1

    Unfortunately, paying somebody to take it off them is really the cheapest option. Grid scale storage systems simply do not exist. Pumped hydro is the closest (only ~25% process loss rate and ~$45 billion per GW in year-round baseload equivalent) and there simply isn't enough places to put them in Germany (at present they have 35 of them, they'd need >500 just to replace the remaining nuclear fleet, not to mention the fossil fuel plants, of which there is 4-5x as many). What's worse, most of the locations for pumped hydro is in the hilly south of Germany, whereas most of the wind resources are in the north, especially off the coast in off-shore wind, so they'll need to beef up their high-voltage transmission network (also add ~7-8% additional transport losses on top). By one estimate, it'll take an additional 100000 to 140000 miles of high-voltage lines to get to their 80% renewable target in 2050. At a cost of ~$1M/mile, that'll be another $100 billion - $140 billion on top of any storage capacity (the government budgets ~$50 billion for new lines through ~2030). Batteries are extremely expensive per Wh stored. If battery storage plants were being built, it wouldn't be shiny recyclable lithium-ion cells, which are expensive as heck (about 5-10x as much as pumped hydro), but the cheapest lead-acid crap you can find. Storage losses in batteries are somewhat lower (only about 5-10%), but their lifetime compared to pumped hydro (~10 years for batteries vs. >40 years for pumped hydro) make the capital expenses impact on ROI much worse. Hydrogen is unfortunately also a no-go. Small scale electrolysis can be up to 80% efficient, but it uses exotic metals on the electrodes and those are consumed over time via ion diffusion. Large scale electrolysis is much less efficient (maybe 50%) and even so nobody's demonstrated that it can be done on a grid level (there's no 500MW electrolysis plant anywhere). What's worse is storage. Hydrogen is extremely nasty stuff, liquid storage requires >1000 PSI (so it takes a lot of energy to compress - another significant efficiency decrease) and it's still about 12x less dense than water, so the tanks have to be HUGE. Metallic pipe embrittlement is a serious issue, as are unintended fires. Imagine a hydrogen storage plant catching fire. Hydrogen is extremely volatile and burns with an invisible flame - enjoy putting those out. The detonation speed is much higher than say butane-air so any detonation of a hydrogen-air mixture is much more destructive than, say, a natural gas explosion. Quite simply, common environmentally conscious people have been not been told the full truth about the scale of the problem by the media and it's no wonder - this is complicated stuff.

  15. Re:WTF? on Germany's Glut of Electricity Causing Prices To Plummet · · Score: 3, Informative

    I'm afraid it's a bit more complicated than that. The EEG is currently running a dangerous experiment with a highly questionable outcome with the German electricity grid and economy. The EEG guarantees renewables a feed in tariff for the next 20 years to make them appear to be ultimately profitable and forces grid operators to take the electricity regardless of the spot price on the market. Grid operators must then direct traditional plant operators to either throttle or even shut down to keep the grid stable. This is a problem for plant operators, because power plants are forced to operate fewer hours of days (prolonging amortization and ROI on the plants) and are forced to operate less efficiently (you know what it takes to restart a brown coal plant?). And what if at some point the grid operators get too much energy from renewables? More than they need or can handle? Well, they transport or even sell it abroad to the Netherlands, Poland and the Czech republic, often at negative prices, meaning, Germany pays for the others to take it. But if you remember, they were forced to purchase the energy at the renewable plant operator (solar or wind) at a guaranteed feed-in tariff, so who's paying for the difference? Partly the taxpayer and partly the grid operator, which is also one of the a reasons why their profit margins are thinning. Sooner or later this mix will blow up into German's faces, but unfortunately, the political elite is in denial, the media fuels an anti-corporatist frenzy and common people who don't know much about how electricity generation, distribution and marketing work such as yourself are simply taken along for the ride on the lie train. And unfortunately, there is no practical solution in sight.

  16. Re:Better headline... on Organic Cat Litter May Have Caused Nuclear Waste Accident · · Score: 2
    It was "hot" in a chemical, not radioactive sense. From James Conoca's article on the subject:

    Beginning over 30 years ago, activities involving separating americium (Am) from old weapons materials generated a moderate amount of transuranic waste contaminated with americium (Am), plutonium, uranium and minor amounts of other radionuclides, and containing various metal-nitrate salts (strong oxidizers), such as (Mg,Ca)(NO3)2 with minor amounts of Fe, Na and K. When dewatered, these hot evaporator bottoms were poured onto a tray, vacuum dried, flashed crystallized, rinsed with cold water and put in bags, where they sat for 30 years.

    [...snip...]

    It was recommended sometime later that inorganic kitty litter made from silicate minerals be added as a sorbent (widely used in radiochemistry as well as the home litter box), but also to dissipate heat and generally mitigate auto-oxidation reactions of the kind we think occurred in these drums in WIPP. Anhydrous citric acid (a reducer) was used to bring the pH down if over-adjusted.

    For reasons perhaps related to good intentions, or merely related to dust generation, the inorganic kitty litter was replaced by organic wheat-based litter early on in the process. There were a few other components of not much import in the drums, but additional organic components just added more fuel.

    Some decisions regarding these additives are vague and not attributable to a real chemist.

    So it seems it was a case of a well meaning idiot making stupid decisions.

  17. Re:Better headline... on Organic Cat Litter May Have Caused Nuclear Waste Accident · · Score: 5, Informative

    First off, this is from the weapons program, not power. Also, not all waste is created equal. Drums are only used for low level stuff - think lab coats, glassware, tools, etc. that at some point might have come into contact with radioactive stuff and so can have trace residue on it. This is *NOT* spent fuel. If you had cared to read the original articles, you'd know that the incident was the first in this facility's 15 year history, wasn't their fault, was extremely small, was immediately contained and rootcaused so that corrective measures could be taken. From where I'm standing, this is a good example of safety working as intended. Unlike your average coal ash spill.

  18. What cute little car on The Brakes That Stop a 1,000 MPH Bloodhound SSC · · Score: 1
    From TFA:

    While most of the retardation will be done by air brakes and parachutes, a set of car-like disc brakes still have to haul it down from 160 mph to a standstill on the slippery earth of South Africa's Kaksken Pan. At that speed, the car's steel wheels will still be spinning at 10,000 rpm.

    If at 160 mph the wheels are spinning at 10,000 rpm, then it means that the wheel are about 14 cm in diameter, which, looking at the Bloodhound SSC side on (http://www.car-addicts.com/wp-content/gallery/bloodhound_ssc/Bloodhound_SSC_01.jpg) means that the car's body is about 30cm tall. Truly a marvel of miniaturization, including the driver! In related news, motoring journalists still suck at delivering factual information to the public.

  19. Re:Lets just keep on trying... on Let's Call It 'Climate Disruption,' White House Science Adviser Suggests (Again) · · Score: 1

    The sicence behind Global Warming is so fake

    If it's so fake, why do you think it is that the vast majority of climatologists (you know, scientists who actually study the climate) are in agreement that climate change is happening and that it's caused by our actions? A vast global conspiracy across thousands of researchers in hundreds of universities and research institutions with no financial, cultural or organizational commonalities? If you think that, then you've got your tinfoil screwed on a little too tight.

    If we REALLY wanted to clean up the environment we would agressive upgrade our energy production facilities like we do with our PC's.

    Fully agree, but it's a little more difficult than with computers - large scale industrial processes aren't so easily modified due to the complexities and the expense involved, not to mention the physical difficulties in achieving quantum leaps in technology other than semiconductors. Here's a hint: you're not the smartest person on the planet, so you can rest assured that other, smarter people have already thought about. Why do you think things aren't moving along as quickly as you think them possible, despite smarter people being on the forefront of them? Do you think it's possible that these much smarter people see a little deeper than you into these areas and have good reasons why they don't think it's as easy?

    Thorium Nuclear power would be a good place to start.

    Thorium is great, but it's still got tons of unresolved issues. Reactor designs need to be developed, certified and tested. The reprocessing and refueling chemistry is still largely theoretical and untested. These are not minor issues, but large projects that will take years, if not decades to resolve and perfect.

    Chemical Fusion

    What's chemical fusion? Chemistry deals with molecules and electron-electron interactions.

    Low Energy Fusion would be another nice place to start.

    Would be, albeit nobody has found a way to demonstrate it. LENR and "cold fusion" are scams.

    We have tons of energy solutions for personal cars/transport and mass transit. We are refusing to do these things because it disrupts the power structures, all of them political.

    Like which ones? Hydrogen fuel cells? LiOn batteries? All of those have serious scaling, performance and cost issues (though BEVs are slowly improving).

    There world seems to be stuck in a rule by Oligarchs

    Ok, un-tighten your tinfoil hat again. Learn about the physics in these areas first - these are NOT easy problems.

  20. The Internet: Where Religions Come To Die on How the Internet Is Taking Away America's Religion · · Score: 4, Insightful

    Great video by a Youtuber on exactly this topic: The Internet: Where Religions Come To Die. Religions simply can't survive on the open marketplace of ideas. Religions work by indoctrination, shaming and isolating subjects to get them to believe absurd shit and then try to shield them from outside influences to make sure they don't find out. On the Internet, this ploy simply doesn't work.

  21. Re:My Advice to Tesla on Tesla Model S Caught Fire While Parked and Unplugged · · Score: 1

    [Elon Musk] is a narcissistic douche

    You mean the guy who spent all of his $150 mil goldmine out of the PayPal acquisition on starting two very risky businesses with high probability of failure - a revolutionary rocket and car business - that actually advanced the state of the art in both fields and influenced the way the public views technological advancement for the better. You call *that* guy a "narcissistic douche"? My response.

  22. Re:Series hybrids on Nissan Unveils 88 Pound 400-HP Race Car Engine · · Score: 1

    Gas turbines are actually pretty compact for the HP rating. Heck, the turbopump on a Merlin 1D rocket engine delivers in excess of 2000hp of pumping power and itself weighs only around 150lbs. The fuel economy is going to kill you, though :D

  23. Re:FEAR! on Mexico's Stolen Radiation Truck: It Could Happen In the US · · Score: 1

    The saddest thing is that this will be sold to the public under the "NUCLEAR POWER BE DANGEROUS!" banner, completely ignoring the fact that this was a radiological source for nuclear medicine - opposing that is in essence saying that you want more people with cancer to die.

  24. Re:Arithmetic denialism on Will Electric Cars and Solar Power Make Gasoline and Utilities Obsolete? · · Score: 1

    Except that only works while there's a fairly small amount of solar on the grid and the government is meddling in the market by imposing regulation such as giving hard preference to solar at the expense of other operators. At higher proportions things stop looking so rosy (recommend you read this nice paper on the real costs associated with intermittency - the reason you're not seeing them in your bill is because of government forcing the price offset onto other users, in effect subsidizing you while taxing others).

  25. # zfs set dedup=on mypool/photos

    Make sure you have enough RAM though (1GB of RAM per TB of unique data) and/or an SSD for L2ARC to make sure it doesn't grind to a halt.