Wikipedia:Reference desk/Archives/Science/2023 September 17

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September 17

“Kilo press”

In the news today; apparently some kind of equipment used in drug manufacture kilo press. No article on it on WP, nor does it google well. Could someone write it? 2603:7000:2940:21:40F6:C37B:9009:3853 (talk) 05:38, 17 September 2023 (UTC)

It's a hydraulic press used to make the compressed bricks of drugs. Here's an FBI pic of one. I don't think there is even a Wikipedia article on illegal drug packaging in general. Abductive (reasoning) 09:10, 17 September 2023 (UTC)

For information: The fox59 link may not be usable outside the USA. In the UK I see "This content is not available in your country/region" and the tab says "Access Restricted". Martin of Sheffield (talk) 09:18, 17 September 2023 (UTC)

It is a clipping of kilogram press, a term used in releases by the judicial system^[1][2][3] and police departments^[4][5] and in news reports.^[6][7][8][9] Since the pressure exerted by one kilogram is puny, the name comes perhaps from the fact that these presses can compress a quantity of one kilogram into a solid brick, as advertized here.  --Lambiam 11:21, 17 September 2023 (UTC)

Wheel load 40 - 50 t/m

This page[10], under section "Crane Sizes & Technical Specifications" lists various Wheel loads from from 30 to "50 t/m".

What's "t/m"?

I think it might be metric ton per meter, but I'm not sure. I googled around and found the Axle load article which says:

The standard rail weight for British railways is now 113 lb/​yd (56.1 kg/m).

I expected a container crane to have a far higher load than a train, but not 900 times more. Satoshit1 (talk) 06:58, 17 September 2023 (UTC)

113 lb/yd is the weight of the rail, not the weight of the train. Quite literally a yard of 113 lb rail weighs 113 lb. See Rail profile#Rail weights and sizes. The axle load article mentions that British practice limits locomotives to 22.5 tonnes per axle whereas the Australian limit is 42 tonnes per axle. Martin of Sheffield (talk) 08:17, 17 September 2023 (UTC)

These port cranes run on rails using groups of wheels. All wheels in a group are connected by balance beams, to make sure all wheels are equally loaded. Within such a group, 30 to 50 tonnes per metre sounds plausible. That number determines the strength of the foundation under the tracks.

For trains, standard axle loads and metre loads have been defined. In Europe, there's a letter for the weight per axle and a number for the weight per metre; German wiki has a nice table: w:de:Streckenklasse. The standard in my country (Netherlands) is that all routes support at least 20 tonnes per axle and 6.4 tonnes per metre (class C2) up to line speed, and most also support 22.5 tonnes per axle and 8 tonnes per metre (class D4) up to 80 or 100 km/h. That's why bulk goods trains are slower than passenger or container trains and can't use some lines during the day. High axle load combined with high speed greatly increases track maintenance, a somewhat unexpected problem when faster trains were introduced in the 1960s and '70s. American and Australian trains are much heavier than European trains, but also much slower for this and other reasons. PiusImpavidus (talk) 09:56, 17 September 2023 (UTC)

How is it possible for a man to become pregnant?

I’ve seen a few people refer to pregnancy in men and I’m wondering how this happens? My understanding of physiology is that a man would not have the uterus required to gestate a fetus. There are also issues regarding gametes (males obviously lacking ova). These are probably the top two things limiting my understanding of how a man could become pregnant. Can anyone explain it to me? Codasoat (talk) 23:08, 17 September 2023 (UTC)

Where did you see this? ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:59, 17 September 2023 (UTC)

Does male pregnancy help? Matt Deres (talk) 00:43, 18 September 2023 (UTC)

Transgender pregnancy is the most relevant article.-gadfium 01:07, 18 September 2023 (UTC)

This just in: Man tests positive on pregnancy test, leaves doctor astonished. Shantavira|^{feed me} 12:07, 18 September 2023 (UTC)

That is a side effect of a metastasised tumour that had invaded his liver. Although the hormones were those usually associated with pregnancy the man was not pregnant. Martin of Sheffield (talk) 14:16, 18 September 2023 (UTC)

As suggested, transgender pregnancy is pertinent. It is referred to in press as a "pregnant man" using self-identification of gender as the definition of "man." It is not "pregnant male" using biological definition of sex at birth. It is likely that this concept if very old as any biological female in history who became pregnant could have self-identified as a man to become the first pregnant man. 12.116.29.106 (talk) 12:56, 19 September 2023 (UTC)