solar water heaters specifically. not the electricity-generating sort of panels
And they were not removed by Reagan. The roof had to be redone and they were simply not re-installed because they leaked so badly and weren't worth the time and expense.
Readit NewsI am not convinced about the wisdom of forbidding to take the hand luggage.
It is true that there are many people who have a big and awkward hand luggage or who need a very long time to recover their luggage from overhead.
There are also many other people who are able to recover their hand luggage from the overhead in less than a second and in much less time than most other passengers are able to just stand up.
I do not see why such passengers should be penalized, even if they would certainly not slow down the evacuation. Losing the documents and data from the hand luggage may cause very serious problems that could need many months of work for solving and passing through many unpleasant experiences until then.
The only argument against this that is correct, is that like in every other domain people would self-assess their own abilities too optimistically, so even those who are slow would believe that they can retrieve their luggage fast enough to not hinder the evacuation, but then they would be proven wrong.
Perhaps the passengers should pass a test of hand luggage retrieval speed, before the flight, in order to be pre-approved for keeping their hand luggage in the case of an emergency landing :-)
There should be a switch in the cockpit that automatically locks all overhead bins if the pilots anticipate an evacuation. This information should be given to the passengers during the pre flight briefing.
hansthehorse commented on Workers at a Boeing Supplier Raised Issues About Defects jacobin.com/2024/01/alask... · Posted by u/lamontcg
It should be remembered that Spirit makes the 737 bare bones fuselage then ships it by train to Boeing. This fuselage had the door plug installed on models that have one. When the fuselage gets to Boing the door plug is removed so the interior team can finish out the component then Boeing (not Spirit) does the final door plug installation.
If it turns out the door plug were improperly installed this is going to all on Boeing.
hansthehorse commented on Nuclear Reactor Simulator dalton-nrs.manchester.ac.... · Posted by u/loopion
Former US Navy submarine nuclear reactor operator here.
Adjusting the steam output was kind of strange. On a submarine, the steam used to propel the submarine dwarfs all the other steam loads. As a result, there's a throttleman who controls that.
Even though this simulation is simplified, it's not too bad. It does hide some of the really interesting aspects of a water cooled/moderated nuclear reactor. The most interesting thing is that water makes the reactor self-regulating because of its negative temperature coefficient of reactivity. I'll explain.
When a uranium-235 atom absorbs a stray neutron, it becomes unstable and splits. This releases more neutrons. Very few of these neutrons will be absorbed by surrounding uranium-235 atoms. This is a good thing. Most will escape the fuel, and some will bounce around in the surrounding water. This slows the neutrons down, and some of them will bounce back into the fuel to be absorbed for more fission reactions.
Let's say 1,000 fission reactions occur. If the result is that 800 neutrons from those fission reactions are absorbed by other uranium-235 atoms, you'll have 800 more fission reactions. The reactor is sub-critical as the reaction will not be self-sustaining.
If 1,000 fissions cause 1,200 neutrons to be absorbed and react, you'll have 1,200 resulting fission reactions. The reactor is super-critical as the number of fissions will increase.
If 1,000 fissions occur and the result is that 1,000 neutrons are absorbed and cause 1,000 more fission reactions, the reactor is critical. "The reactor is critical" means the number of fission reactions is self-sustaining and neither increasing nor decreasing.
How can we affect how many neutrons bounce back into the fuel? We can change the density of the water. It makes sense if you thing about it. The denser the water, the more likely neutrons will hit a water molecule and head back into the fuel.
How can we change the density of the water? We change the temperature of the water. If the water is colder, it is denser and the more likely neutrons will bounce back into the fuel.
How do we change the temperature of the water? We pull more/less heat of out it by using more/less steam.
Putting this all together, as steam demand goes up, more heat is pulled out of the water. This causes colder water to enter the reactor. Colder water will reflect more neutrons. More neutrons means more fission. More fission means more heat. More heat means warmer water and this will attenuate the increase in fission until an equilibrium is reached.
If you're creating too much power, the coolant temperature will increase and the power output will lower. If you're creating too little power, the coolant temperature will decrease and the power output will rise. That's why water is a great coolant/moderator: its negative temperature coefficient of reactivity.
After a civilian nuclear reactor is refueled mtc is positive. It makes for a fun few weeks.
hansthehorse commented on Patients recall death experiences after cardiac arrest nyulangone.org/news/patie... · Posted by u/rntn
As I told the anesthesiologist shortly before one of my many general anesthesia experiences:
The only way I'm going to know whether I died in this room is when I wake up. There is no difference between anesthesia and death.
hansthehorse commented on Why do cats love boxes so much? discovermagazine.com/plan... · Posted by u/helsinkiandrew
A lot of patients every day end up asleep and a fair few say they wish it was longer. I’d be in that group.
The noise is often described as a relaxing ‘white noise’ by this group.
The outer shells are different between vendors and the Philips ones I trained on definitely looked more ominous than the Siemens ones I use now.
The unnerving movement is partially due to the magnet interacting with the inner ear. It creates a sort of vertigo. Explaining this to someone who is anxious seems to help ‘it’s not you freaking out, it’s what magnets do to your inner ear and it eases after a few deep breaths’.
I routinely fall asleep during longer scans. It may be because I've become very familiar with the process.
US doesn’t do it because the highly-radioactive byproducts generated by the reactors were at one point the desired end-product. But even so, it’s a miniscule amount — such that things like “having an off-site storage facility” are problems that have been put off for decades (and probably can be for a few more).
In the US the Carter administration stopped spent fuel recycling due to it's fears of nuclear proliferation. Didn't make sense to me at the time and still doesn't.
what if you just pooled the water until it cooled down naturally under shade before discharging back into the Danube?
Turkey Point plant in SE Florida uses miles and miles of man made switchback canals to cool the discharge before it returns to the plant.
hansthehorse commented on Why does nuclear power plant construction cost so much? progress.institute/nuclea... · Posted by u/scythe
Yeah, but how can that happen in a changing regulatory environment? From the article it seems to me that even if you had built a plant and loved the design, it probably wouldn't be legal to build another one just like it a few years down the road. The author says that part of the reason for cost overruns is that the rules change even after construction has begun.
I worked in commercial nuclear operations for 23 years. It was a two unit site with unit one built first. It was designed as two identical units. By the time unit 2 was finished the regulations had changed so much that final reactor required operators to get a seperate license for each unit.
https://en.wikipedia.org/wiki/Be_My_Baby#Effect_on_Brian_Wil...