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January 13

How can catalyst can speed up chemical reaction without participating in it?

How can catalyst can speed up chemical reaction without participating in it? Rizosome (talk) 02:33, 13 January 2021 (UTC)[reply]

Catalysts do participate in the reaction but they aren't consumed by the reaction.Dja1979 (talk) 06:37, 13 January 2021 (UTC)[reply]

With enzymes (which are biological catalysts), the enzyme typically binds covalently to the reactants at the active site. When the reaction finishes, the products unbind; this is often caused by the enzyme changing shape. A lot of inorganic catalysts work by adsorbing the products onto their surface, which brings the products close together and holds them there so they react with each other. A good example is the Haber–Bosch process. --47.152.93.24 (talk) 01:29, 15 January 2021 (UTC)[reply]

In a letter published in 1957 in Nature, Lionel and Roger Penrose described a very simple mechanical analogue of self-replication.^[1] (demo videos: [2], [3]). I wonder, has anyone tried to construct a mechanical analogue of catalysis, with say three shapes A, B and C, where A and B can interlock and where C facilitates this? So a collection of A and B shapes, when shaken, should interlock at a certain low rate just by chance, but adding some C shapes should speed this up, while the C shapes disengage when an A and B shape interlock so that they can continue their matchmaking. --Lambiam 12:37, 15 January 2021 (UTC)[reply]

Is there any references about ionic insulators?

In the article ionic compound, there is a sentence "As solids they are almost always electrically insulating, but when melted or dissolved they become highly conductive, because the ions are mobilized." Is there any references about it? Such as determination of electrical resistance of solid ionic compounds, or some exceptions. --Leiem (talk) 03:01, 13 January 2021 (UTC)[reply]

Thank you. --Leiem (talk) 09:25, 15 January 2021 (UTC)[reply]

Why so much commercial cultivation of oil-palm in Southeast Asia, and so little in West-Southwest Africa?

I gather that oil-palm plantations in southeast Asia are often highly controversial, given the deforestation and other environmental damage they can involve. It's essentially an invasive species,

My question is twofold: According to our article on Elaeis guineensis, the plant is native to west and southwest Africa.

1. Given that in west-southwest Africa it's a native species, wouldn't you expect to see a significant chunk of the world's palm-oil production come from this region? Why is so much of the stuff produced in Indonesia and Malaysia, and so little in Angola, The Gambia, Senegal, or Ivory Coast?

(There may be issues with these countries in Africa being politically unstable, but this doesn't seem to have significantly hampered other resource exploitation in the region, such as cobalt or cacao).

2. Would cultivation in the regions of Africa where the tree is native likely be more sustainable and do less environmental damage than Indonesian and Malaysian cultivation, all else being equal? If this were the case, surely environmental activists would or should be encouraging these (African) countries to increase their production, to replace the Southeast Asian production?

EDIT: My question is about commercial-scale production, not local subsistence-level production for local consumption. Eliyohub (talk) 06:26, 13 January 2021 (UTC)[reply]

The main reason oil-palm plantations are controversial – next to the exploitation of the workers – is that they are created by the large-scale destruction of rainforest, replacing it by a monoculture, often also appropriating grounds depriving the local population of a livelihood based on crop cultivation. There is no reason to assume the external cost would be any less in areas where the palm is native. As to why there are not more African oil-palm plantations, perhaps there are historical and cultural reasons why there are not more African plantations in general, such as for bananas. Africa accounts for only 10 percent of the global total of forest plantations. [FAO. Global Forest Resources Assessment 2005, Forestry Paper No. 147. Rome, 2006.] Cocoa plantations appear to be an exception; Africa amounts for about half of global cacao production. --Lambiam 07:56, 13 January 2021 (UTC)[reply]

It should also be noted that much if not most of the worlds crops are grown extensively in areas outside of their "native" pre-civilization regions. Honestly, I would be surprised to find a crop where the worlds largest producing regions were the native regions still; I'm sure there are some, but I would never consider there to be enough for it to ever be an expectation. Some examples: Almonds are native to Iran; the world's largest almond producer by far is California. The tomato is native to the pacific coasts of Central and South America. List of countries by tomato production shows that by far the largest producers of the tomato are in Asia (China, India, and Pakistan). Sugarcane, the world's most produced crop, is native to South Asia. The largest producer by far is Brazil. You can repeat this game for lots of crops; the point is that one should disavow oneself of the expectation that because a crop is "native" to a region, that region is the likely place it is farmed. That's not a thing. Whether or not it should be a thing (for any given justification of "should") is a different question. --Jayron 32 15:06, 14 January 2021 (UTC)[reply]

@Eliyohub:, Industrial palm oil investors struggle to gain foothold in Africa says:

"During the late 2000s and early 2010s, some African governments were quick to propose their forested regions as the solution. In what was dubbed the “great African land rush,” some of the world’s largest palm oil producers signed deals across the continent. Many of those deals were massive; in Liberia, for example, concession agreements held by just two companies covered nearly 600,000 hectares (1.5 million acres)...

"...the key factor, the report says, is pushback by communities affected by the projects. Few of the companies that wanted to move into Africa had a plan for a fundamental problem: tens of thousands of people already lived on the land they’d leased. The land deals were often negotiated in near-secrecy and few local communities were consulted by their governments before their territory was offered up to investors; when the bulldozers arrived, trouble followed".

Alansplodge (talk) 16:27, 14 January 2021 (UTC)[reply]

Ffp3 mask

What does ffp stand for As in face mask — Preceding unsigned comment added by 86.24.168.231 (talk) 21:18, 13 January 2021 (UTC)[reply]

Filtering face-piece.[4] ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:07, 13 January 2021 (UTC)[reply]

Thx — Preceding unsigned comment added by 86.24.168.231 (talk) 03:55, 14 January 2021 (UTC) Er, wait I read the link It doesn't say that — Preceding unsigned comment added by 86.24.168.231 (talk) 04:03, 14 January 2021 (UTC)[reply]

The second paragraph includes "Recently, it has been recommended by the Royal College of Ophthalmologists (RCOphth) and the British and Eire Association of Vitreoretinal Surgeons (BEAVRS) that we use filtering face-piece (FFP)3 masks during vitrectomy surgery in all patients, in addition to eye protection related to the potential for aerosol production [1]. " — Preceding unsigned comment added by Baseball Bugs (talk • contribs) 05:38, 14 January 2021 (UTC)[reply]

We have an article on FFP standards. DuncanHill (talk) 17:53, 14 January 2021 (UTC)[reply]

"Sub-" in geography

Is there a specific, commonly accepted, meaning given to the prefix "sub-" as used in geography? I know it literally means "below" or "under", but what does it means in words like "subpolar", "subtropical" or "sub-Saharan"? Subpolar regions are on lower latitudes than (so, in a sense, "below") the poles, but then, subtropical regions are on higher latitudes than the tropics (so why not "supertropical"?). Could it mean "outside", with the subpolar regions being around the poles, the subtropics being on either side of the tropical zone and sub-Saharan Africa being most (but not all) of Africa outside the Sahara? — Kpalion^(talk) 21:27, 13 January 2021 (UTC)[reply]

The "Indian sub-continent" does not refer to India etc being located below the rest of central Asia but to its being smaller than a continent proper. -- Jack of Oz ^{[pleasantries]} 22:30, 13 January 2021 (UTC)[reply]

The prefix can mean in general three different things: under, beneath as in sub-saharan or subculture; subsidiary, secondary als in sub-continent or subroutine; and almost, nearly, approximately, somethling less as in subtropical, subarctic, subequatorial or subclinical, see e.g. en.wiktionary.org, merriam-webster.com 2003:F5:6F0C:8700:988A:3855:258A:E6D9 (talk) 23:12, 13 January 2021 (UTC) Marco PB[reply]

Okay, the third meaning (something less) makes sense for subpolar, subtropical and subcontinent. But how does the first meaning (beneath) make sense for Sub-Saharan Africa? It only would, if it were located underground, buried beneath the Sahara. — Kpalion^(talk) 23:31, 13 January 2021 (UTC)[reply]

Sub-Sahara is south of the Sahara, hence "under" the Sahara on a typical map. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:17, 14 January 2021 (UTC)[reply]

I just came across suboceanic, which I think means "inland". Abductive (reasoning) 08:51, 14 January 2021 (UTC)[reply]

No, it means "beneath the ocean floor". ←Baseball Bugs ^{What's up, Doc?} carrots→ 09:32, 14 January 2021 (UTC)[reply]

Not always, you should check. Abductive (reasoning) 19:50, 14 January 2021 (UTC)[reply]

I googled the term and that's what I found. Can you find another definition? ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:52, 14 January 2021 (UTC)[reply]

Influence of Site and Stand Factors on the Distribution of Crustose Lichens of the Caliciales in a Suboceanic Spruce Forest Area in Central Norway. Abductive (reasoning) 01:50, 15 January 2021 (UTC)[reply]

Of course, map orientation is arbitrary, so there's no logical reason to equate "south" with "down". But then, not all terminology has to be logical. Can you think of any other examples where "sub-" is used to mean "south of"? — Kpalion^(talk) 10:00, 14 January 2021 (UTC)[reply]

In England (specifically, not the rest of the UK) during the 13th and 14th centuries, after the Normans had taken over, Latin (as well as Norman-French) elements were sometimes added to Anglo-Saxon place names to clarify geographical locations, and hence ownership, for the educated, Latin-literate overlords and their clerics: one of the elements was sub, such that a village X (say) might be named "X sub Y" to indicate its position relative to Y (thus distinguishing it from other places also called X. (Another such element was cum when, for example, two villages were combined into a single parish or other administrative unit, such as Prestwich-cum-Oldham.) Whether or not the "sub" indicated relative altitude, or distance "down" a river, or that X was south of Y, I don't know, but someone with access to a database gazeteer and with the requisite search skills might be able to investigate the question. {The poster formerly known as 87.81.230.195} 90.200.40.9 (talk) 14:06, 14 January 2021 (UTC)[reply]

There is the idiom go south for taking a "downward" turn – a turn for the worse. --Lambiam 11:09, 14 January 2021 (UTC)[reply]

That's true, but I don't suppose geographic terminology is based on English idioms. — Kpalion^(talk) 12:32, 14 January 2021 (UTC)[reply]

The very term we're examining suggests that some may be. At least it's not called Darkest Africa any more. Matt Deres (talk) 14:21, 14 January 2021 (UTC)[reply]

The phrase "go south" is an example of the opposite phenomenon: English idiom based on geographic terminology. --Khajidha (talk) 15:57, 14 January 2021 (UTC)[reply]

As are the phrases "up North" and "down South" commonly used in England, which amusingly seem to conflict with the railway-related usage of always going "up" to London. (The latter allegedly derives from the earliest railways, for coal waggons which free-ran downhill from the mineheads to the riverside coal staithes and were then horse-hauled back up to the mines where the companies involved had their hedquarters. {The poster formerly known as 87.81.230.195} — Preceding unsigned comment added by 90.200.40.9 (talk) 17:18, 14 January 2021 (UTC)[reply]

In a few places, the term "down East" is used in the US (Maine and North Carolina), and confusing to outsiders "down Cape" is towards Provincetown when on Cape Cod, which depending on which part of the Cape you're on is either east or north. And, of course, "down the river" depends entirely on which direction the river in question is flowing. --Jayron 32 19:58, 14 January 2021 (UTC)[reply]

Specific to sub-Saharan, see here. First known use was 1899, and it is explicitly referring to "South of" rather than "lower in altitude" or "under". Also, remember that language is neither consistent nor logical. It is often enough to confuse you into thinking it should be, but one should never have the expectation that it must be. The fact that south really isn't "down" in any meaningful sense except by convention of the way maps are hung on walls, doesn't mean people don't use the terminology equating south to down in their language. Doing so is only wrong in the annoyingly pedantic sense, and so long as everyone speaking already understands the context, it's really not a problem. And once people who don't know the context have it explained to them, they no longer have an excuse for being confused. --Jayron 32 14:57, 14 January 2021 (UTC)[reply]

I must say I didn't expect logic and consistency in everyday expressions like "go south", but I did in scientific terminology. But I take it that even this expectation was wrong. Thanks to all for your answers. — Kpalion^(talk) 18:32, 14 January 2021 (UTC)[reply]

Sub-Saharan is not scientific terminology; consistency in scientific terminology only occurs in very specific situations where there is an active standards body that publishes and enforces such standards, such as the IUPAC for Chemistry nomenclature; still even so some non-standard terminology persists in chemistry literature, such as acetic acid instead of the formal "ethanoic acid". Even highly specialized terms like entropy have similar but non-overlapping meanings from different fields. Language consistency is constantly confounded by real humans, who keep using it the wrong way. Sorry about that. --Jayron 32 18:53, 14 January 2021 (UTC)[reply]