sethoflagos

This is a typo that I make all too frequently. I believe that it's because I've written or typed these words so many thousands of times that I don't need to think about the individual letters; the pattern for typing the entire word is firmly ingrained in muscle memory and can be reproduced automatically as a single unit. Exactly the same way an experienced musician can execute fast scales and arpeggios without thinking about the individual notes. The problem is that these words are also homophones, so if the trigger for generating the motor pattern is the sound of the word in your head, the brain has three different patterns to pick from. Inevitably, it may pick the wrong one from time to time. Also none of these examples are typically emphasised in a sentence, and the mind is likely to be focussed elsewhere. So I can't see myself confusing weir & we're for example, though I might have to watch myself with wares, wears & where's. Those who dismiss such errors as illiteracy or laziness might perhaps take a quick glance into a mirror.

Apologies. Not aware there was one. Where do I find it? Done.

No, it's not quite so easy. The diffusion function you seem to be looking for is an appropriate solution to Fick's 2nd Law for your specific geometry. Have a look at https://en.wikipedia.org/wiki/Fick's_laws_of_diffusion and in particular the section "Example solution 1: constant concentration source and diffusion length".

As there seems to be some link to a physiological context, might the OP be referring to neural firing rates? Not my field but I think it's common knowledge that nerve signals are either on or off, and therefore have to convert stimulus amplitude to frequency as and when required (eg pain receptors etc.). I can see diffusion rates of neurotransmitters etc released during the off and on states possibly playing some part in setting the time period(?). Just a guess. Post Script - I just pulled up the calculator link provided by the OP and there's a heavy emphasis on neurotransmitter diffusion. So less of a guess now.

Gymnaspics?

Given the scenario presented, the occupants are hit by a surge wave (essentially water-hammer) generated by the almost instantaneous deceleration of the incoming flow reaching something it can't shift (the water coming in the opposite direction). We generally estimate this initial spike with the Joukowski formula which is summarised here. From the figures given, the Joukowsky 'spike' looks to be around 0.6 GPa (~6,000 bar), so 'Yes', very much so. In passing, I would be very surprised if there were any significant heat transfer during such an extremely rapid deformation process. Simply not enough time.

I was told to rotate the workpiece 900 at every grit change. Different set of objectives perhaps.

Depends on how exactly the word is understood. I guess there's an unspoken assumption here of the early 20th century switch in meaning to modern pantheists and nature-worshippers of a distinctly English tradition (a far cry from its original meaning of 'peasant'). If that's the concept we're working with then I'd tend to look at trends in book and DVD sales of Lord of the Rings rather than tiktok polls. I feel that being a 'free spirit' and self-identifying as part of a countable group are mutually exclusive.

I did my apprenticeship in a paperboard mill where we regularly ran a grade for conversion to fish boxes for storage and transport of frozen fish. Typical product range details can be found at https://diepvriesurk.nl/en/packaging/carton-packing/ Storing such boxes in strong direct sunlight would not be recommended. Why would anyone want to do this?

Guess I'm fortunate that all my stainless polishing needs (trumpet valves mainly) are quite adequately met by Duraglit. Well-over 50 years regular use and no freakish accidents yet, touch wood.

GRIND GRIND GRIND GRIND GRIND GRIND GRIND GRIND GRIND GRIND GRIND GRIND buff buff buff Many. This is a typical medium duty one for an industrial workshop. From whatever a decent domestic power drill costs these days upwards. Consider looking at taking a training course in basic metalworking first. It is REALLY easy to lose an eye or a finger with these things if you get it wrong.

It was indeed. There are quite a few episodes of Up Pompeii floating around Youtube space.

The 2nd Law formally states that the primary prerequisite for an isentropic process is that there is no nett exchange of heat with the surroundings. Since heat transfer (and other dissipative processes such as friction) are relatively slow processes then fast processes lean toward the isentropic. Like a power station? Near isentropic compression and expansion through the boiler feedwater pumps and steam turbines respectively are extremely rapid. But the working fluid spends far more residence time exposed to the heat transfer surfaces. The steam condenser is intrinsically near isothermal in operation, and although the radiatively heated water wall is not, the ancillary surfaces: deaerator, economiser, superheater and reheater bundles; are sized and positioned so as to maximise overall station thermal efficiency. Which is equivalent to saying that they are designed to fit the station cycle to the Carnot optimum theoretical cycle as closely as possible. I guess this is not what you envisage when you write 'engine'. A better word may be 'machine' which has a precise engineering meaning: a device that transforms one form of energy into another. Heat engines, electrical transformers and power stations are all machines by this definition.

Fast processes tend towards the isentropic. Efficiency and overall economics work hand in hand. Isothermal processes in extremis call for infinite cycle time and/or infinite heat transfer area. The economics just don't work as a practical proposition so we have to compromise. There is really no such thing as a Carnot design as it is an abstract theoretical concept: not a tangible object like an Otto or Stirling engine. Some designs can approach the Carnot limit more closely than others and that's all there is to it. Closer approaches need bigger budgets with ever-declining potential Return On Investment.

Bump.

'Half-empty' is a misleading concept when your gas density is >80% of the liquid density as in this case. Even if the receiving cylinder were free of liquid, at pressure it's still > 80% full. A syphon discharge from below the liquid level of the main storage vessel will definitely get a few more pounds delivery, though some of this will evaporate on transit. If the deficit is so important, then you could consider placing the receiving cylinder in a bath of iced water both prior to and during filling. This will condense everything coming in from the supply vessel. Even if the supply vessel pressure falls to 40 bar or so, the receiving cylinder will repressurise when returned to ambient so maybe think twice before exceeding the cylinder's rated CO2 weight capacity.

I've been a heavy smoker since I was 19. Just background fact. After maybe 17 malaria-free years in Nigeria, I eventually came down with it in 2016 (P. falciparum) and running 400 C I was immediately hospitalised for 3 days on a combination quinine/paracetamol drip. This repeated 2 years later. On both occasions, I had three days of no urge to smoke whatsoever, which was a really big deal to me. Normally two hours abstention pushes me into a tense, hyperactive somewhat sociopathic state that can alarm those around me. Basically. I smoke to stay in employment (and married!). So any way out of this circular trap would be highly beneficial. Of course, I discussed this with the medical staff responsible for my treatment, but they showed not the slightest interest whatsoever. Which didn't impress me much. I doubt that it's malaria that will kill me in the long run. When the treatment finished, immediate cold turkey. A third infection a couple of years ago I self-medicated with artemisinin/lumefantrine combination (+paracetamol as antipyretic) which worked but didn't give the same respite from my nicotine addiction. Has anyone the slightest inkling of what may be behind the addiction respite? I can't find anything relevant online, and I've looked. Numerous times.

Introducing the air at the base would require much more compression, and since the expansion occurs overwhelmingly in the top couple of hundred metres, that's where the suction will be generated in any case. There are such animals as flexible submarine hoses (eg here), but these are highly complex composite builds that have other issues to address. I would have thought that rigid wall piping was mandatory whatever the pumping method. I'm not clear on what sort of flowrate we are supposed to be considering now. For the Mm3/s range, a somewhat buoyant cylindrical honeycomb structure a couple of km in diameter held in place by a suitable spread of anchor chains strikes me as potentially feasible. It could conceivably be constructed predominantly from a couple of km3 of reprocessed plastic waste which would be one approach to carbon sequestration. Whether appropriate or not for the climate, as a technical challenge, this topic has some very interesting aspects. It's still performed some PdV work on its surroundings, so yes, there will be a corresponding if small adiabatic temperature drop.

Beat them to it by spontaneously launching your own preferred non-contact greeting.

PS: I was going to say something about whether polyethylene was up to handling the considerable tensile forces involved, but perhaps we can save that for later. And for >>1m in the previous post please read <<1m. I really must get my eyes checked.

Actually looking at this a little more closely, if the 1 metre diameter pipe (say 0.785 m2 cross-section) were to oscillate the full one metre wave height (crest to trough I assume) and back every 5 seconds then 0.785 / 5 x 3600 x 24 = 13,572 m3/d at 100% efficiency doesn't it? So how does the quoted 13,000 m3/d amount to 60% efficient operation? Now I'm a little suspicious. The pipe is tracing a displacement ca. h = 0.5 sin (1.26 t) m where 0.5 - wave height / 2, 1.26 = 2 x pi / wave period Hence pipe velocity dh/dt = 0.628 cos (1.26 t) m/s Pipe acceleration d2h/dt2 = - 0.792 sin (1.26 t) m/s2 Mass of pipe contents ~ 0.785 x 1,025 x 1,000 = 804,625 kg Maximum upward force exerted by buoy = 0.792 x 804,625 = 637,007 N = 64,954 kgf neglecting friction So the buoy must be capable of developing a lift of 64,954 kgf with >> 1 m displacement from the ocean surface. Clearly some displacement is required so let's take 0.1 m Buoy cross-section >= 64,954 / 1,025 / 0.1 = 634 m2 hence buoy diameter >= 28.4 m That's pretty big even by single buoy mooring standards but I guess it can't be ruled out as a concept. For a moment I thought we were looking at a supertanker hull.

An interesting paper. The technical feasibility and volumetric scale factor of the scenario is defined by the following: The Kithil reference was rather difficult to locate but I eventually found it here. So the pumping principle is essentially that of a wave-powered shaduf (no disrespect - it's just a mental picture). Perhaps we should note that wave height and period given here are roughly in tune with a consistent 20 knot wind which implies installation in the 'roaring forties' for example..

The game changer appears to be arbitrarily reducing the seawater flowrate by a factor of 106 and moving the seawater intake from the abyssal plains to 3 parts of the way up the continental rise. Are we done with the original thread?

At the instant you posted the OP, it is more than arguable that the universe of the current instant didn't exist. It had no mass, possessed no energy, occupied no space. In short, it was the absolute nothing you referred to in your OP. Yet now the present exists in all its spacious, energetic enormity. How did it arise from absolutely nothing? If absolute Now has a perfect inverse Now such that Now + Now = 0, then perhaps they can and do arise spontaneously in a manner consistent with all our expectations of conservation of funamental properties, and separating as Now tracks its property gradients in one time direction while Now tracks its own back into the past. Hence Now deevolves back into Then. at exactly the right time to meet the instant you posted the OP whereupon Then + Then = 0. Hence the past also vanishes for eternity into absolutely nothing. And so on until the first Dawn where there was no Then to annihilate with. So Dawn and Dawn evolved in perfect mirror symmetry. For a better explanation of this inverse universe idea see Advanced Waves Detected (John G. Cramer) on which my amateur musings borrow heavily.