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Comment Re:6.8 Billion (Score 1) 344

Well, smaller reactors will have a lower non-leakage percentage due to the decreased number of mean free paths the volume covers which will affect the effective multiplication factor, but the total macroscopic cross section can be increased by fabricating with a higher fissile number density in an attempt to overcome this or even having a specially-designed reflector. As for economics, the idea behind Small Modular Reactors is that the n-th of a kind product, assuming a factory exists to pump them out, will ultimately be far more cost effective than the monolithic reactors we have today and, in some scenarios, even treated as commodities on the international market. But there is still a lot of research to due to overcome the current industrial-scale inertia, and if countries like the U.S. continue to experience the 2%-ish annual energy growth, large monolithic reactors may still have their place on the grid in a low carbon energy future.

Comment Re:Parody (Score 1) 255

I didn't ignore it but simply didn't consider the dilution of the brand as a reason to deny a fair use argument and still don't. I quote page 781 of the SCOTUS document:

The fair use doctrine thus “permits [and requires] courts to avoid rigid application of the copyright statute when, on occasion, it would stifle the very creativity which that law is designed to foster.” ...

The task is not to be simplified with bright-line rules, for the statute, like the doctrine it recognizes, calls for case-by-case analysis.

Denying a work the protection of fair use due to the possibly that other less-deserving works might take the same path goes against the very essence of fair use.

(P.S. Sorry for the late reply. You know, life).

Comment Re:Parody (Score 4, Interesting) 255

Fair enough. But let me put on my lawyer hat (i.e., go to Wikipedia, try to find a pertinent precedent, find the actual opinion, and quote like hell) and see what I can do. ...

I reference Campbell, aka Skyywalker, et al. v. Acuff-Rose Music, Inc. from the United State Reports Volume 510: Cases Adjudged in The Supreme Court at October Term,1993 (PDF page 773).

Concerning the fair use defense of 2 Live Crew to parody Roy Orbison's song "Oh, Pretty Woman", to quote Justice Souter's opinion for a unanimous Court decision (pp. 782-783):

The first factor in a fair use enquiry is ... to see ... whether the new work merely "supersede[s] the objects" of the original ..., or instead adds something new, with a further purpose or different character, altering the first with new expression, meaning, or message; it asks, in other words, whether and to what extent the new work is "transformative."

I would argue, thought I'm sure not without debated, that POWER/RANGERS fulfills this transformative requirement of fair use.

Concerning the issue of parody, Justice Souter goes on to say (p.784):

For the purposes of copyright law, the nub of the definitions, and the heart of any parodist’s claim to quote from existing material, is the use of some elements of a prior author’s composition to create a new one that, at least in part, comments on that author’s works.

POWER/RANGERS offers the perspective, or critique, of teenagers being recruited to fight an intergalactic war with more actual war-like elements that stand in stark contrast to the light-hearted portrayal of the sampled work. It mimics the characters and world but does make a point: war isn't as fun as was shown.

Concerning the issue of excessive use of elements from the original work, the Justice says (p.792):

Parody presents a difficult case. Parody’s humor, or in any event its comment, necessarily springs from recognizable allusion to its object through distorted imitation. Its art lies in the tension between a known original and its parodic twin. When parody takes aim at a particular original work, the parody must be able to “conjure up” at least enough of that original to make the object of its critical wit recognizable.

I would argue that the author of the work in question took as many elements as needed to make the parody recognizable to the audience such that the parody would function. In taking those elements however, the author did transform a number of aspects to suite the intended parodic purpose of the piece (e.g., newly added machine guns, Bulk and Skull turning homicidal, the protagonists losing and dying).

Lastly, concerning the economic incentive, the Justice states (p.794):

[The fourth fair use factor] requires courts to consider not only the extent of market harm caused by the particular actions of the alleged infringer, but also "whether unrestricted and widespread conduct of the sort engaged in by the defendant . . . would result in a substantially adverse impact on the potential market" for the original.

Since the work is blatantly made without the desire of monetary feedback, is not intended to supersede or replace any of the extant or future productions of the original work or author, and has done nothing but bring attention to the original work through this parody, the fourth factor of fair use is satisfied.

But again, I'm no lawyer. I just play one on Slashdot.

Comment Re:Parody (Score 1) 255

But it is intentionally parodying Power Rangers by its very tone and visual style relative to the source material. Just because the actors don't wink at the camera doesn't mean they're are not poking fun at both the show and the remake craze.

But I do feel this short film is devisive on this reason for a similar reason that Verhoeven's Starhship Troopers was: if you take yourself too seriously, people won't know what think or, worse, complete misinterpret you. Or maybe I've just internalized Poe's Law too much.

Comment Re:Fusion isn't "expensive", it's lossy (Score 2) 315

It is indeed about accessing the energy already stored, which is what Q > 1 means. The Second Law of Thermodynamics will come into play when they convert that energy into useful work and electricity.

And the power conversion system is almost never talked about when fusion reactor designs are presented. Their journal article actually does mention a power cycle, which is nice to see. And they nonchalantly decided upon a supercritical CO2 Brayton Cycle to "maximize the overall efficiency". Reading through the small section on this, I don't think they've fully considered the extra engineering involved in dealing with that fluid (which can be quite corrosive for a number of materials) and the required experience to actually maintain that system. The choice seems to be one of what hip-and-new versus solid, robust technology (I don't know why people are afraid of water-based Rankine cycles; they're so nice). Their neutronics check out, but their power cycle analysis is lacking.

Comment The NRC's job is safety (Score 5, Informative) 135

The NRC's job is safety. That's it. They have people stationed at power plants, and their only job is to ask questions and enforce policies such that the plant operates safely. With that beaten home, let's get to some specifics.

The biggest concern for the current fleet of U.S. reactors (mostly all Generation II designs) in terms of long operation is embrittlement of the reactor pressure vessel (RPV) due to radiation damage (mostly neutronic). Embrittlement of the RPV comes into play when severe accident responses (for either Design Basis Accidents (DBAs) or Beyond Design Basis Accidents (BDBAs)) dictate fast, extreme cooling of the RPV that can lead to pressurized thermal shock (PTS) events. The biggest hurdle toward getting approval is proving which-and-every way to a high confidence level that a PTS breach of the RPV will not occur from this embrittlement. If plants cannot do this, the NRC will not issue a license extension because the plant cannot prove its safety. If you care to read more on it, consult 10 CFR 50.61 for details (or the whole thing at the10 CFR 50 Part Index.

Are there other requirements? Yes (see the 10 CFR 50 index above). However, this is the one aspect I wanted to expound upon since turbomachinery has been replaced/upgrade, fuel is refreshed every 18 months or so, and piping is constantly checked. But I wanted to stress the safety issue. The NRC has 100% no qualms about telling a plant "no" if that plant cannot prove it is safe to operate.

Comment Re:Not the way to economical fusion power generati (Score 2) 109

Actually, ITER is supposed to be a proof-of-concept. That is, ITER is designed to show that a controlled and burning plasma can be created and sustained over a long period of time with a net power out (like any baseload power plant should). It's a toroidal tokamak simply because it is one of the most well-understood fusion reactor designs; spherical tokamaks, inertial confinement, electrostatic confinement, and (my personal favorite) stellarators being less so.

DEMO, another experiment, is the next step and is intended to be the bridge between ITER and a commercial design. What is DEMO is still up in the air, but it will definitely be influenced by lessons learned from ITER and other various research institutions (like, shameless alma mater plug, UW-Madison with its toroidal tokamak, spherical tokamak, and stellarators experiments).

Comment Two misleading statements (Score 4, Informative) 162

The post states that the paper "is claiming to have found the solution to another Millennium Prize Problems" while the article's title is “Existence of a strong solution of the Navier-Stokes equations". By my interpretation, the paper is claiming to show the existence of strong solutions (that is, solutions satisfying the Navier-Stokes equations in non-Weak Form subjected to some set of boundary data) not a general (or any) solution, in particular. While the proof of existence is the Millennium Prize if the proof includes smoothness (continuity after some degree of differentiation), the fact of whether or not these solutions exist is irrelevant to most (if any) Fluid Mechanics texts and engineers/modelers.

The post also states that the Navier-Stokes is "fundamental [set of] partial differentials equations that describe the flow of incompressible fluids"; this is true if all the physical parameters (density, viscosity, and pressure) are taken as constants such that an equation-of-state and energy equation are not needed. However, if they are not assumed constant, the Navier-Stokes equations also perfectly describe the flow of compressible fluids if equipped with an energy equation, an equation-of-state, and other constitutive relations as needed. The only rub comes in when dealing with a fluid that is either not a contiguous field (such as fluids that break-up when immersed in another or, in some cases, a fluid undergoing phase change) or a fluid that does not obey the Stokes Hypothesis (an extension of the idea of a Newtonian fluid to multiple dimensions) which is used as a constitutive relation for the stress tensor in the Navier-Stokes equations.

Comment Re:PDFs? (Score 1) 843

I was thinking the opposite. Since a Word Documents (.doc or .docx) require, by definition, Word to view on a computer, I would assume more people would publish/save to/print to PDFs since the format is highly portable with many free readers.

That is if the intent of the document is to be viewed. If it is to be edited amongst a group, feel free to choose in the group the editor/creator of choice. Word, Abiword, Lotus Symphony, OO Writer, LaTeX, Google Docs (where I mainly created in HTML and CSS when I do) ... There are a ton of document creators out there; no reason to hate on just one because everyone uses it (or just doesn't know about others).

Comment Re:Externality (Waste Disposal) (Score 1) 575

Where does the waste go?

The used assemblies, usually on a 12-18 month cycle, will be put into wet storage (a big pool of cooled water) for a period of time until all highly radioactive/short half-life substances have decayed to reasonable levels. Then they will be put into dry casks and stored on-site until such a time as the Federal Government opens a suitable long-term or interim storage repository.

What is the cost of waste disposal?

Nuclear waste disposal and technology development is all on the Federal Government. As per the Nuclear Energy Act of 1982, the generators (plants) will pay the DOE 1 mill/KWe-h (1 $/MWe-h) to assume ownership of the waste.

Have they factored that cost into their calculations?

Under the assumption that TVA is a money-making entity and has a finance department, I would assume they do

Comment Re:is nuclear power clean? (Score 1) 867

Not only that but if not for massive government subsidies nuclear power would not be profitable, it may actually loose money.


That is a funny thing to say considering that in 2007 the U.S. gave 4,875 million dollars to renewables (81% in Tax credits) opposed to 1,267 million dollars to nuclear (72% R&D) and 5,451 million dollars to Coal/Petroleum/Natural Gas.

Energy Information Administration Report

Comment Re:Not many choices... (Score 1) 867

No need for a correction. The heat/kinetic energy from both fission and fusion reactions comes from the mass difference of the product(s) and reactant(s). The difference lies in that fusion combines light nuclei resulting in a surplus of energy per nucleon while fission divides heavy nuclei resulting in a surplus of energy per nucleon.

Comment Re:Not many choices... (Score 1) 867

No need for a correction. The heat from nuclear fission and fusion chain reactions comes from the mass difference between the products and reactants of the reaction. The difference lies in that fusion combines nuclei to achieve a higher energy per nucleon while fission divides nuclei to achieve a higher energy per nucleon.

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Faith may be defined briefly as an illogical belief in the occurence of the improbable. - H. L. Mencken