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Comment: Transmutation in SFRs or LWRs too (Score 4, Informative) 187

by ghack (#47097095) Attached to: US Nuclear Plants Expanding Long-Term Waste Storage Facilities

The link goes to information about proposed accelerator driven subcritical reactors, but you can transmute plutonium, minor actinides, and fission products in sodium fast reactors (SFRs) or light water reactors with inert matrix fuel (LWRs). SFRs have nearly the same spectrum neutron energy spectrum as most proposed ADS blankets, and the technology readiness level is much higher. Basically anything you can do in an ADS you can do in an SFR, but you don't have the added cost of an accelerator. Moderated targets would be required for fission product transmutation.

Passive decay heat removal is necessary whether you are talking about an ADS or an SFR. Other than the worst reactivity insertion accidents (which can be mitigated by negative reactivity coefficients) I do not see serious benefits to an ADS over an SFR.

Comment: 2011 Refurbs (Score 2) 359

by ghack (#45999041) Attached to: GPUs Dropping Dead In 2011 MacBook Pro Models

Some early/late 2011 refurbs have been popping up on the Apple Refurb Store occasionally still (although there are none on there now there was some several weeks ago). My guess is these are machines Apple is replacing for folks with AppleCare and then they are replacing the logic board and battery and reselling them as refurbs.

I have a late 2011 (a work machine with applecare) and have never seen any issues.

Comment: Global vs. local effects (Score 5, Interesting) 517

by ghack (#45938289) Attached to: How Weather Influences Global Warming Opinions

Global warming is exactly that- a global trend, not a local one. Locally, the effects have been most pronounced near the north pole, which is not exactly a place where many people live.

Global climate change seems to have resulted recently in a "warming" trend, but as we know from Al Gore's movie, if the North Atlantic current gets shut off we are in for a polar vortex on a much longer time scale.

I am not sure who coined the phrase "global warming"; is it a PR failure by the scientists involved or a reporting failure by the news media? To quote a well known meme: "why not both?"

Comment: Re: Uh, that's a huge spread (Score 1) 226

by ghack (#45933361) Attached to: Record Wind Power Levels Trigger Energy Price Fall Across Europe

He said 'short term' ... that means for me in hours or less.
Current reactors don't do that. If you power a reactor a bit down it gets difficult to power it up again, due to different characteristics of moderation (waste products).

The difficulty is due to xenon, which can limit the magnitude of the load follow. However, trust me there are reactors that can follow. History of load following reactors from the American Nuclear Society

Comment: Re:bfd (Score 4, Interesting) 226

by ghack (#45929627) Attached to: Record Wind Power Levels Trigger Energy Price Fall Across Europe

Although wind power does not contribute to global warming through greenhouse gas emission, it does extract kinetic energy from the atmosphere and therefore may alter global climate even at continental scales

It may be the lesser of evils compared to some other supplemental energy options but it isn't perfect- and it isn't a good candidate for base load

Comment: Re:Uh, that's a huge spread (Score 2, Informative) 226

by ghack (#45928891) Attached to: Record Wind Power Levels Trigger Energy Price Fall Across Europe

On a daily basis, December was a month of extremes for Germany, with day-ahead base prices closing on December 10 and 11 at less than €60/MWh – the highest over-the-counter levels seen all year – only to fall to its lowest level December 24 to €0.50/MWh.

I have seen a nice bumper sticker before: Solar and wind are allright, but nuke's do it all night.

I agree with this sentiment. Shame Germany is phasing out nuclear in favor of coal.

Comment: Hypothesis vs. conclusion (Score 2) 247

by ghack (#45877467) Attached to: Is Earth Weighed Down By Dark Matter?

The dark matter ring is merely a hypothesis. In my field (or science, engineering, or mathematics generally) we should follow the scientific method when reporting results at a meeting.

This guy was unfortunately presenting a hypothesis. He should have waited and tried to find more compelling evidence before presenting. New Scientist should be familiar enough with the scientific method to avoid publicizing a radical and unproven hypothesis.

+ - Isaac Asimov's 50-Year-Old Prediction for 2014 Is Viral and All Wrong->

Submitted by Daniel_Stuckey
Daniel_Stuckey (2647775) writes "So the internet has obviously exalted over noted non-ass Isaac Asimov's vision for 2014, which he articulated in a New York Times opinion piece in 1964. The sci-fi writer imagined visiting the 2014 World Fair, and the global culture and economy the exhibits might reflect. NPR called his many predictions, which range from cordless smart telephones, to robots running our leisure society, to machine-cooked 'automeals', "right on." Business Insider called the forecast "spot on." The Huffington Post called the projections "eerily accurate."

The only thing is, they're not.

Taken as a whole, Asimov's vision for 2014 is wildly off. It's more that 'Genius predicted the future 50 years ago' makes for a great article hook. Asimov does hit a couple pretty close to home: He got pretty close to guessing the world population (6.5 billion); he anticipated automated cars ("vehicles with 'robot brains'"); and he seems to have described the current smartphone/tablet craze ("sight-sound" telephones that "can be used not only to see the people you call but also for studying documents and photographs and reading passages from books.")"

Link to Original Source

+ - Graphene research heats up in Asia->

Submitted by Taco Cowboy
Taco Cowboy (5327) writes "Graphene, the wonder material, has attracted a lot of research all over the world, and in Asia, in particular.

Since it's discovery in 2004 by two Russian scientists Andrei Geim and Kostya Novoselov, Graphene research has grown leaps and bounds in all direction.

In Asia, countries are competing against each others in committing resource and talents into Graphene. In the tiny island state of Singapore, for example, about half a billion dollar worth of resources have been invested to facilitate the R&D of Graphene. South Korea has reportedly invested more than 2 Billion for Graphene research. Other countries such as Japan, China, Taiwan, and India have also joined the fray, in hot pursuit for the wonder material.

http://www.physics.iisc.ernet.in/~arindam/research/Graphene.htm

http://mag.digitalpc.co.uk/Olive/ODE/physicsworld/LandingPage/LandingPage.aspx?href=UEhZU1dvZGUvMjAxMy8wOC8wMQ..&pageno=MTQ.&entity=QXIwMTQwMA..&view=ZW50aXR5

http://www.asianscientist.com/in-the-lab/researchers-grow-graphene-silicon-wafers-2013/"

Link to Original Source

Comment: Should've carried them on (Score 1) 894

by ghack (#45841901) Attached to: US Customs Destroys Virtuoso's Flutes Because They Were "Agricultural Items"

I don't really agree with most of this comment- but I do agree he should have kept them with him.

Wife and I learned the hard way when we had a bunched of stuff stolen out of our luggage flying from ORD to IST- if something has monetary and/or sentimental value, always keep it with you.

Turkish airlines sent us $100 check for the $500+ stuff that was stolen.

Comment: Maybe profit is one motivation... (Score 3, Insightful) 579

by ghack (#45791161) Attached to: Utilities Fight Back Against Solar Energy

Excess energy on the grid is a real issue, especially if there has been a significant wave of people adopting these systems. If there isn't demand for all the electricity being pumped onto the grid, there has to be a place to dump the energy. This is an even bigger issue with wind and other intermittent sources.

If the grid is overwhelmed and there is no demand, should folks expect to get paid for that energy, which could actually cost the utility money to dump somewhere?

Something else to bear in mind- the utility has to operate base load plants no matter what.

Recent literature indicates that these issues can be overcome (one example from Utilities Policy ), but that the process will take time. Utilities are a very conservative industry and are often slow to adapt new systems because they have stringent boundary conditions.

Just playing the devils advocate here- I'm sure profit is a part of it.

Some people have a great ambition: to build something that will last, at least until they've finished building it.

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