Recent content by Grelbr42

In the commuter train parking lot I use, there are "disabled" parking spots close to the train. OK. That's great. How did they decide how many such spots there should be? The lot is nearly 1/4 taken up by designated accessible spots. They are nearly all empty, pretty much every day. Usually...

You should be thinking of the impulse you get per kg of fuel. That depends what efficiency you allow each type of system. And what rocket exhaust velocity you allow for the mass you chuck out the back. If you allow perfect efficiency fusion, fuse 1 kg of Hydrogen to Helium, you get about...

Yes. In that whatever number of particles have been run when the time is exceeded is what is used in the tallies. If you have enough particles to get good stats, great! If not, then you get bad stats on that run.

Just for fun, try writing that as 10000000000 not 1E10. It probably won't make any difference, but it might. I don't recall exactly what the limit on an integer is for MCNP 5, but I seem to recall it was bigger than 1E9. If you are still getting answers with too large uncertainty, there are a...

The sock problem is long solved. They cling to the inside of the dryer due to static. I go to laundromats and check the dryers. Checking ten dryers can often net you three or four unmatched socks. All freshly laundered.

Did he hold his hand palm out or palm in? https://www.oxfordreference.com/display/10.1093/oi/authority.20110803120300620;jsessionid=26D95F84B39D78036F7796424BBBBCA4

Recently I watched my brother swap the winter tires off my car for the summer tires. I have been watching him put a secondary roof on the shipping containers he has behind his house, in prep for putting solar panels on them. Recently he put new pistons in the engine of a more-than-60 year old...

Do you mean, how can such folks post things on ArXiv? https://info.arxiv.org/help/submit.html

What does the Laplace operator look like in spherical polar coordinates? If you then have this operator act on the following what happens when the "r" part of the operator hits the "Y" part of the function? And similarly for the angle parts acting on Rl(r)? The buzzword is "separability."...

You really need to get yourself one of the standard handbooks on radiation protection. Maybe you can get it from your local university library if you don't want to pay for it, or if your company does not want to pay for it. Possibly if you Google search for standard handbook of radiation...

Today I learned where the serviceberry gets its name. It comes from the fact of the time of year when the plant flowers. The flowers were taken to indicate that the soil had thawed enough such that graves could be dug, and so funeral services could proceed properly...

Devices of this type are used for a couple purposes. One is to store keys to a nearby door. You flip down the cover and it exposes a keypad. Inside is the key to the door. It's often used, for example, for parts lockers. This way, you can give out the combo to people who are supposed to be...

I would say, if it is a situation that matters, do not trust anything on WP. Never use it as a primary source. Sometimes you can use it to "get up the learning curve." But basically, keep in mind that it is created by a bunch of "wander-by" volunteers. I trust it about as much as somebody I...

Background The usual way MCNP works is to give you tallies on the basis of "per particle started." So, whatever you are tallying, say energy deposited in a target, you get the result per particle started. Then your normalize by multiplying by the number of particle per second in your source...