Wikipedia:Reference desk/Archives/Science/2015 August 12

= August 12 =

ROVs
What types of ROVs are used in maritime rescue work? 2601:646:8E01:9089:2C02:9BB5:5007:AC7 (talk) 00:43, 12 August 2015 (UTC)


 * The US Navy developed the Submarine Rescue Diving Recompression System for rescuing the crews of sunken submarines. Not sure if there are any other drone rescue craft actually in operation. A number of countries have been discussing the use of unmanned aerial vehicles to locate, but not rescue, victims of maritime disasters. Someguy1221 (talk) 02:00, 12 August 2015 (UTC)


 * Thanks! Any ROVs out there for saving drowning people?  I'm making a game document for a co-op multiplayer rescue simulator, you see, and I want to know what types of vehicles I should include.  The SRDRS will definitely be included, along with it's manned counterpart the Mystic-class DSRV (hey, where the hell did that article go -- it was there just the other day?!) -- any others I should put in there? 2601:646:8E01:9089:2C17:EABD:3104:7BA2 (talk) 05:43, 12 August 2015 (UTC)


 * DSRV-1 Mystic. Someguy1221 (talk) 07:17, 12 August 2015 (UTC)
 * NATO is working on the ICARUS search-and-rescue vehicle, and Israel has developed the Silver Marlin. The Silver Marlin was primarily developed as a weapon system, but is also advertised as a search-and-rescue vehicle. Googling "unmanned rescue boat" turns up a great many pages describing similar vehicles in development by public and private organizations, but I assumed you only wanted ones that actually existed. Someguy1221 (talk) 07:25, 12 August 2015 (UTC)


 * Thanks a million, once again! Yes, I want ROVs which either exist in real life or at least have their detailed designs finalized, and it doesn't really matter if they are designed for something else, as long as they have a solid search-rescue capability.  Now, one last question: On How It's Made, in the "Underwater Robots" episode, they showed the manufacture of a robot which can actually submerge and recover drowning victims from underwater -- anyone happen to know the model name? 2601:646:8E01:9089:2C17:EABD:3104:7BA2 (talk) 07:40, 12 August 2015 (UTC)


 * Regarding how it's made, I'm not sure what the model number was, but the submersible they showed was built by SeaBotix. Maybe that will help you track it down. Someguy1221 (talk) 07:55, 12 August 2015 (UTC)


 * Thanks once again! 2601:646:8E01:9089:2C17:EABD:3104:7BA2 (talk) 10:51, 12 August 2015 (UTC)
 * Follow-up: In case anyone else wanted to ask the same question, I tracked down the ROV in the "How It's Made" episode, and it was really somewhat of a mix-up on their part -- the capabilities that the narrator was talking about applied to the SARbot, but most of the video footage showed another model, the LBV200-4. 2601:646:8E01:9089:A5A7:EFF3:62C3:EFD8 (talk) 04:47, 14 August 2015 (UTC)

Chemical composition of liquid paraffin (medical type)
I'm trying to find out the chemical composition of liquid paraffin. Apparently the medical type is distinct from the type used as a fuel. In particular I'm interested in the range of lengths of the carbon chain. --78.148.104.21 (talk) 17:18, 12 August 2015 (UTC)
 * Our article on this substance-application is Liquid paraffin (medicinal). DMacks (talk) 17:29, 12 August 2015 (UTC)
 * ...and neither it nor the parent Mineral oil article on the family of substances covers typical chain-length for various purposes:( It's certainly a pretty large chain, given vapor pressure is negligible and flash point is >180°C (per its MDS). If you have a list of alkanes, knowing the density is 0.845g/mL might give you an approximate length. DMacks (talk) 17:35, 12 August 2015 (UTC)
 * This links says chain lengths between C14 and C30. https://books.google.com/books?id=vPUOgqtxd-kC&lpg=PA778&ots=iQyfO1eFFe&dq=paraffinum%20liquidum%20carbon%20chain%20length&pg=PA777#v=onepage&q&f=false Justin15w (talk) 22:00, 12 August 2015 (UTC)

How big was the Chernobyl explosion?
How big was the Chernobyl explosion? E.g. in terms of TNT tonnage or something else? I know it wasn't a nuclear detonation. --78.148.104.21 (talk) 23:19, 12 August 2015 (UTC)


 * Doesn't look all that big considering it was nuclear. According to this site (which has a little bit of a commercial interest), maybe 300 tons of TNT.  This source and this source both says about a tenth of that.  30 to 40 tons seems a safer bet, with 300 being exaggeration or a typo.  Ian.thomson (talk) 23:27, 12 August 2015 (UTC)


 * EDIT: Double checking, the source I've scratched out is self-published. That said, the one I've bolded is from Infobase Publishing, so I'm gonna say that their figure of 40 tons (36 metric tons) is accurate. Ian.thomson (talk) 23:29, 12 August 2015 (UTC)


 * It was not "nuclear" at all in the sense of being a nuclear explosion. It was a steam explosion of the reactor. The idea that nuclear reactors can explode like nuclear bombs is an extremely common misconception. The effects of the Chernobyl disaster were from the breach of the reactor and the resulting fire, which spewed the radioactive fission products around. --108.38.204.15 (talk) 23:59, 12 August 2015 (UTC)


 * Actually our article (Chernobyl_disaster) gives a 10 ton-equivalent nuclear "fizzle" as one of four possible causes for the second explosion. Rmhermen (talk) 03:12, 13 August 2015 (UTC)


 * This is a photo of the power plant from two years ago. There are so many trees now that it is hard to see it. You can see that there was certainly no 300 megaton explosion because it is not reasonable to believe that the woodland animals rebuilt all the power station buildings after the humans left. 209.149.114.32 (talk) 13:47, 13 August 2015 (UTC)
 * Who knows? Maybe the radiation exposure created a race of hyperintelligent squirrels who are rebuilding the plant to power their civilization...-- Jayron 32 15:03, 13 August 2015 (UTC)


 * And, in case it isn't obvious to all, the issue wasn't the size of the explosion, but rather the release of radiation, just like at the Fukushima Daiichi nuclear disaster. 15:35, 13 August 2015 (UTC)


 * I finally found a good photo of the building after the explosion here. It is obvious that it was one building, very destroyed. It didn't blow up the entire power center. It really didn't blow up the entire city. If you want a non-radioactive equivalent, see the Oklahoma City bombing here. It has been estimated at 0.002kt (see our article). 209.149.114.32 (talk) 16:33, 13 August 2015 (UTC)
 * I got a 'file not found' page with your link. Dismas |(talk) 02:43, 14 August 2015 (UTC)
 * I've been within 100m of it (so sorry, this is original research) and although you cannot see inside the old sarcophagus you get the impression from the guides and display photographs that the explosion was pretty timid. Bent metal, and that sort of thing.188.247.76.211 (talk) 06:51, 14 August 2015 (UTC)


 * While the Japanese immediately took care of the Fukushima Daiichi Power Plant, the Russian tried over days to fight the fire in the reactor of Chernobyl Nuclear Power Plant. A telephone call to Moscow was done by the Swedish diplomatic staff asking are you killing us? Did you drop an nuclear bomb? No Moscow answered to Stockholm, why are You asking? … Moscow called the Chernobyl Nuclear Power Plant, is everything fine? – We have a little fire in the plant. – Oh really, we already heard form your litte fire. We want you to get here immediately and tell us about the fire in the reactor… Lessions in management followed and the disaster took lots of peoples health. The Japanese had the problem not to know what happend to the valves in the coolant system when the backup generators failed, there was no relyable monitoring of the plant anymore. So they had no idea what to do next. They were still trying. The scanario was not covered by emergency traing. A good advice is to order a helicopter with water and control the values manually, but this scenario was not supported by design. It seems, some of todays automotive engines were lubricated more relyable as some nuclear reactors operate it's cooling systems. -- Hans Haase (有问题吗) 18:40, 14 August 2015 (UTC)