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Messages - a10t2

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3196
The Pub / Re: Japan quake
« on: March 18, 2011, 02:25:32 PM »
I used to mine Uranium underground. I worked in quite a lot of radon, and had to be put on the surface a couple times to "cool" off.  What irks me is that we used RADs and now we are using a total different scale and that just keeps me learning I guess...

Yeah, I don't have much of an intuitive sense for sieverts either. Fortunately the conversion factor's easy: 1 Sv = 100 rem. AFAIK the industry in the US has gone metric on everything else, but for some reason we're stuck on rem.

I have immense respect for you guys who knowingly dosed yourselves day after day. I've had to take exactly one decon shower (my lab partner dropped a sealed source and it broke open) and even through my dosimeter only picked up 20-25 mrem it was absolutely terrifying.

Japan today raised the threat level for the crisis at the Fukushima Daiichi nuclear plant from a 4 to 5 -- putting it on par with the 1979 crisis at Pennsylvania's Three Mile Island.

Which doesn't surprise me from all the reports that we've been getting.

Me neither. The problem with the INES scale is that it stipulates "at least one death" for a level 4 accident and "multiple deaths" for a level 5. So while the radiation releases from this accident are many orders of magnitude higher than at TMI, it doesn't really fit neatly into the criteria. They're being very conservative with both the public evacuations and the worker dosage limits, and at this point I'm optimistic that once it's all said and done there won't be any radiation deaths.

3197
The Pub / Re: Do you know your State Capitals? - Friday Fun
« on: March 18, 2011, 02:12:09 PM »
I got 49, but it's my own fault - I was clicking through too quickly and missed Texas. :-\

Here's a fun trivia question: What are the four state capitals not served by an interstate highway?

Edit: Speeling...

3198
The Pub / Re: Lunar Perigee
« on: March 17, 2011, 08:23:05 PM »
Sweet.  Maybe a10t2 can tell us why it looks bigger, and the vertical1 can tell us why the world might end. ;D ;)

I was going to, but now I think my feelings are too hurt. :'(

3199
The Pub / Re: Japan quake
« on: March 17, 2011, 06:17:24 PM »
Ok Gurus, The fallout from the path of that plume is leaving a deposit of material on / thereby in the pacific. What is the effect of that, dead or sickly floura and fauna?

Probably not. The highest number I've seen reported is 400 mSv/hr, which by the time it's dispersed in the atmosphere isn't going to be enough to be noticeable. (To put things in perspective, 1 mSv is about the dose you'd get by eating 1,000 bananas.)

3200
The Pub / Re: Japan quake
« on: March 17, 2011, 01:28:44 PM »
If radiation weighting factors for xray or gamma photons or electrons of any energy are 1 and alpha particles possess a factor of 20 why wouldn't it be preferable to be exposed by gamma rays?

Alphas are little trickier in that they are very high-energy, but also very massive. The median stopping distance for an alpha in air is about 20 cm IIRC. So the thing you have to remember with the quality factor tables is that they're for radiation that's already in the body. Alpha emitters that aren't ingested are essentially harmless; they have a quality factor of 0. And like I said earlier, most alpha emitters (and all the long-lived ones) are transuranics. There are chemical toxicities associated with them as well, and they don't play any role in any biological systems I'm aware of. So alpha exposure is only an issue with fallout - if there's radioactive dust in the air and you breathe it or it ends up on crops and you eat it, there could be major health issues. But even in a worst case scenario, Chernobyl-type release (which would be physically impossible in the Japanese BWRs anyway), all you have to do is wear a mask and rinse your food with water, and your alpha dosage drops to zero.

BTW, I forgot to post the link to the *only* news source I've been able to follow that has up-to-date, factual information specifically about the nuclear issues. It's the IAEA's facebook page: http://www.facebook.com/iaeaorg The times, they are a-changin'...

3201
Yeast and Fermentation / Re: Starter Questions
« on: March 17, 2011, 09:05:22 AM »
When propagating a blend, all the rules go out the window. So let's just ignore the Brett.

Assuming your pack is pretty fresh (85% viability), you could do a 1.5 L first stage, 2.3 L second stage. That gets you to your ~550 billion cells.

http://seanterrill.com/2010/03/08/two-stage-starter-calculations/

3202
The Pub / Re: Japan quake
« on: March 17, 2011, 08:44:09 AM »
If im not mistaken the plants lost power and there was no other way to pump water to the cooling towers setting up a chain of events that either may or will lead to a full out meltdown.

That's not entirely correct. This was a triple failure. The earthquake severed the power lines operating the pumps, as a result of which the backup generators kicked on. Minutes later, the tsunami washed through and destroyed the backup generators. In the following days, with grid power still not available, hydrogen explosions and fires pretty much destroyed the rest of the plants' systems, and ensured that any containment measures taken would be irreversible. That's worth repeating: as soon as they had the opportunity to do so, the operator junked all four reactors, including the two that were apparently under control. None of them will ever operate again, and the capital cost alone of that will certainly exceed a billion US dollars.

All that aside, these reactors were designed to survive a 7-8 Richter earthquake (depending on whose scale, and whose reports you choose to believe). To anticipate the reactor cores surviving a magnitude 8.9 quake is like expecting a car that's certified safe in a head-on collision at 60 mph to also survive a collision at 118 mph. The fact that (apparently) only one of the four pressure vessels has suffered a breach is a testament to how over-engineered they are.

This is an accident of almost incomprehensible scope, for the nuclear industry, and a radiation release of unforgivable scale. That still doesn't make it dangerous. Why we play by different rules than other power plants, I don't know, but there you have it. Every story about this will use the word "Chernobyl", but the phrase "Deepwater Horizon" will fade from memory within a few years. I don't think there's anything funny about the situation. But I also won't stand silent in the face of that kind of hypocrisy.

If anyone has factual questions about nuclear power, or the dangers of radiation exposure, I'll answer them to the best of my abilities.

3203
The Pub / Re: Japan quake
« on: March 16, 2011, 06:31:56 PM »
She's gone from suck... to blow!

Now that's just silly. I'm warning this thread not to get silly again.

3204
The Pub / Re: Japan quake
« on: March 16, 2011, 01:19:09 PM »
The workers have fled (supposedly) due to the radiation.
The utility evacuated non-essential personnel after a radiation monitor at the gatehouse spiked to 6 mSv/hr, with consistent readings over 2 mSv/hr. There are still about 50 people working inside the perimeter.

3205
All Grain Brewing / Re: Adding Magnesium to Brewing Liquor
« on: March 15, 2011, 11:39:37 PM »
This doesn't provide definitive guidance on Mg's effect of yeast growth and performance, but I believe that it doesn't hurt as long as the Mg concentration is kept moderate.  You will start to have taste impact at concentrations of 30 ppm.  Therefore, I recommend that a preferred Mg range is 5 to 30 ppm in the mash and sparging water.

Based on the only controlled study I've seen on it, there isn't an impact on fermentation performance until you get over 200-300 ppm anyway. I'll try to dig up the paper when I get home.

3206
The Pub / Re: Japan quake
« on: March 15, 2011, 10:54:12 PM »
Make a really long pipe.  One that stretches from the ground up into outer space.  At one end you have a vacuum, at the other end you've got 1 atmosphere of pressure.  A 14.7 psi of pressure differential... Voila!  instant vacuum cleaner.

Unless you've figured out a way to turn off the gravity inside the pipe, I don't think you've cracked that nut yet. ;)

3207
The Pub / Re: Japan quake
« on: March 15, 2011, 04:45:03 PM »
Yes, but which ones turn you into the Hulk?  Gamma.

See? It's win-win. SEAN SMASH!

3208
The Pub / Re: Japan quake
« on: March 15, 2011, 04:19:30 PM »
Hopefully any "fallout" will end up in the Pacific before it blows over the US mainland or any islands. I'm more fearful of alpha and beta than gamma so would like to see that stuff in the ocean than on human skin, crops or living enviromments.

That's pretty much backwards, actually. Alphas are high-energy, but most of that is tied up in their mass (~4 amu). They can't even penetrate skin. Plus most of the major alpha emitters are transuranics, so there's limited potential for uptake into the ecosystem. Betas are a little bit more of a concern, but most of the emitters (with the notable exception of Sr-90) are prompt sources, so by this point they've already been through a couple half-lives and are falling off. The major sources of radiation in nuclear fuel are the long-lived fission products like Cs-137, which tend to be gamma emitters. They have half-lives of a few decades, and limited potential for chemical toxicity, so they tend to wind up in the environment.

3209
General Homebrew Discussion / Re: Surface Sterilization of Dry Hops
« on: March 14, 2011, 10:14:01 PM »
I've never heard of a brewery doing that either, and a search at ProBrewer didn't turn up anything. I think the biggest negative is that you'd boil off some of the volatile aromatics. So you wouldn't get as much bang for you buck as you would by just throwing in the hops. You'd also isomerize some alpha acids, but unless you were transferring the water along with the hops I don't think there would be a perceptible increase in bitterness as a result.

3210
So before I pitch my yeast I should probably take a least one more gravity reading after a good aeration, correct?

In my experience you still won't be able to get consistent readings. The only way to be accurate is to take the reading from the wort before topping off, then divide by the dilution ratio.

Also, I get an estimated OG of ~1.077, so you may not have been as far off as you think. That's assuming 43 point-gal/lb for the DME, 36 for the LME, 45 for the brown sugar, and 38 for the honey.

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