exchemist

First of all, what evidence do you have for your claim that the reasons for the use of warfarin as an anticoagulant are to do with excess Vitamin K? I'm on an anticoagulant myself - though not warfarin - because I am susceptible to atrial fibrillation, which apparently can lead to strokes, that's all. Vitamin K doesn't come into it.

On the railway thing, the 3rd rail is always turned off in the event of needing to evacuate a train. In fact, on the London Underground the driver even carries (or used to) a bar to short the rails himself and trip the circuit breakers, if the controllers don't turn it off for him. (Must make quite a bang. What fun!) II'm sure the same would happen with an elevated railway. So nobody would mess about with rope ladders. Nobody except an utter idiot misses his stop on a railway. The trains stop at every station, they are all clearly signed and, as you say there are even recorded announcements nowadays to help the blind - and the drunk. So there really is no reason to rely on landmarks. If you know the city well enough to recognise the landmarks, you will also know the station to get off at. Elevated railways are an appalling eyesore for the city and tend to cut communities in half, so pretty terrible in terms of urban planning. We have some in Docklands (Docklands Light Railway), but that is in former industrial areas so no established community is wrecked by them. London does have Victorian elevated sections of the suburban railway (and the District Line of the Underground), on brick viaducts. The arches have become garages, workshops even restaurants in some areas, but they do still cut up the neighbourhood. Underground is better, if the geology is favourable, as it was in much of London on the north bank of the Thames. To the south it is different (a lot of sand and gravel, which is far harder to tunnel through), which is why the Underground network is far more extensive north of the river.

I suppose you can ensure the solution is saturated by having some free crystals at the bottom. But then I think you need to make sure your chosen seed crystal is the largest, as I seem to recall the largest one will grow at the expense of the smaller ones, due to it being fractionally more stable (more favourable ratio of stable sides to less stable edges).

I can barely summon the energy for this, but...[stifles yawn].... because there are many other types of component in most machines of any complexity: off the top of my head, gears, blades, cranks, pistons and cylinders...oh and probably most crucial of all, bearings, both plain and rolling element type - plus a host of others, not least sensors of various kinds and microprocessors. Now let's guess what happens next. I reckon you will claim, in some way, that all of these can be treated as special cases of the six items on your original list. At which point it will be "Thank you and goodnight" from me. 😉

You could use a very fine mesh over any openings, known as mosquito netting. The mesh size needs to be 1mm or less - and, therefore, so do any gaps where the mesh is attached. Mosquitos (the females) feed on blood, in order to get the nourishment they need for egg production. Human beings are not an alternative to water for them. Insects do not impale themselves on barbed wire, as a rule.

Of course not.

Your hovercraft appears to be full of eels.

In my case I just sleep badly in a strange environment if it is not quiet - and planes never are, even if they lay off the announcements. In fact I am only now starting to get a good night's sleep on the overnight ferry from Portsmouth to St. Malo, now that the sound of the engines and the faint motion have become familiar. But not flying any more is one of the blessings of retirement, in my opinion. The whole experience is vile. But the seat-cum-bed did help a bit on the longest journeys.

As the bed is made from a fully reclined seat, you don't have to. You can un-recline it at your convenience.

Excellent point about the mosquitos - I was forgetting that. I seem to recall in Dubai we weren't allowed to have any standing water in gardens, apart from swimming pools that were treated and circulated. Even in London, in a water butt with a lid on it, I find I get quite a few mosquito larvae in it, in summertime.

I've looked into this a bit more and it seems I was at least partly wrong to say gravity is responsible for the restoring force in the very fine ripples one sees on the surface of a liquid in a glass. These ripples are, it seems, something called capillary waves: https://asa.scitation.org/doi/10.1121/1.2019710 In capillary waves the dominant restoring force at very short wavelength is surface tension rather than gravity, though gravity plays an increasing role as the wavelength goes up: https://en.wikipedia.org/wiki/Capillary_wave However I don't think surface tension will result in true elastic behaviour either, as the restoring force on a wave crest or trough will not increase linearly with deformation (i.e. stress is not proportional to strain).

Gosh that is weird. So 2 x 55USG barrels. But that's fair bit. I just have one barrel, but my garden is not a big one. So far as I know I can have as many as I like. In fact we are all encouraged to use rainwater, since if we don't it all goes into the main sewer (no dual system in London) and in heavy rainfall that creates problems for the waste treatment plants. What we do sometimes get is a hosepipe ban in summer if water is short. As such times a water butt is very handy.

What? You mean it's illegal to have a water butt connected to the gutter on your roof? Surely not. Where is this? I have one because I have camellias, which don't like the high pH of London water, coming as it largely does, from chalk hills. Very useful in dry weather. Oh I see. I have not heard of that, but it could easily be done, once one has the dual sewer pipework system installed in the community. (The example I gave was from N Ireland, where it rains all the bloody time, so I suppose they just want o get rid of it! )

You are advised to keep yourself loosely strapped even when in the bed. A PA warning is not adequate - you can get turbulence with no warning. The way they handle the space is to have basically a seat that reclines flat. They arrange these in a sort of staggered arrangement that minimises the wasted space. But this is only feasible for a business class or 1st class seating arrangement of seats in pairs between each aisle. They can't do it for the 3 across arrangement, so far as I know. But it's more than ten years since I last flew long haul on business so things may have changed.

There are beds in long haul business class on some airlines. I've slept in them (badly). But not bunks: you don't want people falling out if you get turbulence.

Well we've had water butts for centuries, to collect run-off from roofs. But run-off water won't generally be suitable for drinking, because of what is on the surfaces it runs off. And some countries, or areas, have sewer systems that keep rainwater run-off separate from waste water. So there is exactly the infrastructure you are talking about in some places. Here's an example (N Ireland) : https://www.nidirect.gov.uk/articles/connecting-your-home-right-drains

Bye.

Don't forget you can apply the Sine Rule to the big triangle as well as to the 2 smaller ones. So, for example, you can make ratios of Sin 48deg with TV as well as with TD.

No. You've been given 2 ideas on what to do so now you need to show some initiative. We don't just give answers here, because that does not help people learn.

Sine rule?

Mr Bean again. You've done this before, haven't you?

It maybe be a bit of a tangent to your request but, when I retired, I was given a fantastic present by the team I worked with, which was software that scans a musical score and turns that into audio. I was able to use it to send music files to members of a choir I sang with, in which I could separate out the various voices in the harmony, so each could learn their part. It was called Sibelius. I think there are several on the market.

It's been fun. Hope we both got something out of it, anyway.

Zero is also part of the set of real numbers, isn't it?

I don't know the answer: I was hoping you might, having had it drawn to your attention! But, looking at the ring structure of lactose, on the glucose ring one of the -OH groups is part of the hemi-acetal. If you exclude that one, there remain 3 of them on the glucopyranose ring and 4 on the galactopyranose ring. HOWEVER, looking in my ancient Finar Part 2 (old-fashioned, even at Oxford in the 1970s!) it looks to me as if the methylated OH that is part of the hemi-acetal is hydrolysed in the following hydrolysis step, leaving you with only 3 methylated hydroxyls on the glucose side. So that would account for it. (That would make sense as acetals are easily hydrolysed to give the aldehyde or ketone.) I think that's about the best I can do on this. I hope you can construct an answer now that makes some sort of sense. If we've got it wrong, I'd be interested if you can come back here and let me know the right answer in due course. I must say I found carbohydrate chemistry terribly confusing and tedious, due to the close similarity of all these structures. And the lecturer we had was the most boring man imaginable. So I'm afraid the details are not something that has stayed in my mind 45 years later......... 😁