Wikipedia:Reference desk/Archives/Science/2021 October 13

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October 13

fenilbeta

In Primo Levi's If This is a Man (chapter Die drei Leute vom Labor), he tells his experience of how, while working at the "chemical" Kommando at the Buna plant near the Monowitz concentration camp, he had to work with fenilbeta. It comes in 60-Kg bags. It has a sharp odor that gets in the prisoners' uniforms. If it gets between the skin and the uniform in summer, it sticks to the sweaty skin and corrodes it. I suspect it is PHENYL-beta-NAPHTHYLAMINE but there is no article about phenyl-beta-naphthylamine. There are two articles about Naphthylamine, though. My questions are:

• What is the usual name of fenilbeta?
• What is it used for (especially at the Buna plant)?

Thanks. --Error (talk) 00:39, 13 October 2021 (UTC)

In Survival In Auschwitz (p. 136) by Primo Levi, it is translated as "phenylbeta". Alansplodge (talk) 10:44, 13 October 2021 (UTC)

Possibly:

N-Phenyl-beta-Naphthylamine is a light tan or gray flake or powder. It is used in making rubber products, other chemicals, and as a stabilizer in lubricants. This chemical is no longer used in the United States... Contact can irritate the skin and eyes. [1]

Buna Werke was a synthetic rubber plant.

Alansplodge (talk) 11:09, 13 October 2021 (UTC)

See the Pubchem summary of uses, section 10.4 and the short WP article de:N-Phenyl-2-naphthylamin (in German), which confirms Alansplodge's suggestion. Mike Turnbull (talk) 11:43, 13 October 2021 (UTC)

Regarding reverse current after zener breakdown

Can I light the bulb from circuit even after zener breakdown? I know reverse current gradually increase after increasing input voltage after zener breakdown. I am confused because of the term "reverse" present here.Rizosome (talk) 02:21, 13 October 2021 (UTC)

I think you need a much more better understanding of basic electromagnetic terminology, such as "current," before you start trying to understand much more complex concepts, such as zener breakdown. I'm not trying to be condescending, either, but you have had several questions recently that show a fundamental misunderstanding of what terms like "current" mean. Just as one should learn to walk before they learn to run, you probably need a more basic understanding of electromagnetic theory before jumping to things like the Zener effect that depend on things like quantum tunneling or understanding p–n junction type semiconductors. --OuroborosCobra (talk) 20:46, 13 October 2021 (UTC)

Ok, is this reverse current from aforementioned zener breakdown considered as Backfeeding? Rizosome (talk) 05:05, 14 October 2021 (UTC)

Swimfins' drag

To what extent, if any, the swimfins' advantages are offset by the muscular efforts to overcome drag, which is greater than without them? Thanks. 212.180.235.46 (talk) 20:04, 13 October 2021 (UTC)