Enthalpy

NaCl vs KOH is just experimental knowledge. If you leave a packet of table salt open, it takes weeks to get damp. Do the same with NaOH (and KOH does supposedly the same) and soon you get a paste. I did the experiment of moisture absorption. It was glycerine (known to be hygroscopic), impregnating a cloth, left in open air in a workshop. I measured the mass every day. It took weeks to add 10% to its mass. So with just an open canister there's nothing to worry about. And, yes, ethanol will evaporate.

When each solid remains pure, the case is easy to understand. Molecules can separate still as easily from the solid to float away in the liquid (ptovided both liquids mix easily), while there are fewer molecules of the proper kind in the liquid that can deposit on each solid. This favours melting.

Insensitivity of light to electric fields and their gradient, too. Having zero rest mass, which combines with light speed, looks uncompatible with one or two charges, as this means energy at rest.

Hi rpenner, nice to see you here!

It happens in materials where electrons have a negative mass, in metals just as in semiconductors.

I have no objection based on orbital mechanics against the coilguns on space stations. But practical objections, sure. Departure from Leo to lunar transfer takes about 3.2km/s, braking at the Moon 1km/s. With rockets, both use fuel so mission planners add the expenses, but with the coilgun only the acceleration needs energy. However, 10 tons would demand a heavy space station, because already 50m/s changes the orbit a lot. 10t and 3.2km/s make 51GJ, or 70t lithium batteries and heavier capacitors, with efficient coilguns that don't exist. 60kW from solar panels provide this energy in 10 days. And, well, we don't have the proper electric guns. Gravity assist: I have the biggest doubts that a craft accelerated by the Moon could come back to a station on Leo. There are angle conditions on the craft's orbits before and after the flyby, and if the return angle is symmetric I vaguely feel that no speed has been gained. But I'm not easy with gravity assist. Some other scenarios have been proposed, like Halo and Kolomaro transfers, between Earth and Moon or Mars. I don't know how they work, it could be a tidal effect. For sure, such transfers are very slow, taking many orbits of the Moon or planet.

This is exactly the kind of "explanation" you should neglect and avoid. Thinking at that will bring you nothing. Go straight to the proper decription of light, with electric and magnetic fields, and with photons: it's less abstract than this kind of philosophical descriptions, and it works.

All planets are near the ecliptic plane, but objects beyond Neptune have randomly distributed orbit inclination - these are too small to be planets. The same pattern applies to the moons of Jupiter, Saturn and to the Milky Way. I imagine (but could be horribly wrong) that gas and dust concentrate in a disk early as the system forms, thin because of shocks, but wide because of the pre-existing rotation, and that nearer to the centre this happens faster. Then planets and moons form, consequently in a plane for those near to the centre.

These are the technology development for the last architectures I described as of today, with the date of first suggestion and if possible a search keyword. ---------- Processors Explicit macro-op instructions, 01 January 2016, search "macro-op". Meaningful for any Cpu, most useful for the simplest ones with lowest consumption. The compiler must be adapted. This needs thoughts and paperwork first, possibly at a university or elsewhere. Cpu optimized for integer add and compare at low power. 31 January 2015. Hints on 26 February 2015, 12:44 AM. Description on 25 October 2015. Useful for databases, web servers, web search machines, artificial intelligence as noted on 31 January 2015 and meanwhile. This can begin as paperwork before switching to a semiconductor company. Cascaded logic instruction, 26 February 2015 two messages, search "cascade", and Wide cascaded logic instruction, Jul 06, 2016 6:34 pm, search "wide cascade". Mostly for databases, web servers, web search machines, hence belongs to any Cpu. Small hardware development immediately at the silicon design company. Extensions to the optimizing compiler by the editor, may benefit from theoretical thoughts at a university. Find string instruction, 26 February 2015, search "string". For any Cpu. Some existing Cpu must already offer it. Hardware development at the silicon design company. Extensions to the optimizing compiler by the editor. Complex 32b mul-acc, 18 October 2015 - 01:25 PM, search "complex". Multiple flow control units, 26 October 2015, search "flow control". Subtract-one-and-branch instruction, 26 October 2015, search "subtract one". Desired everywhere outside linear algebra. May well exist already. This can begin as paperwork before switching to a semiconductor company. ---------- Memory Common point: at most one Dram chip per computing node, with enough throughput to feed the processor. Dram chip with many accesses, 19 November 2013. Full-speed scaled indexed access, 19 November 2013, search "scaled". For any Cpu, Gpu, gamestation, database, web server, number cruncher. Needs clear thoughts before, possibly at a university. Then, easy silicon. Full-speed butterfly access, 19 November 2013, search "butterfly". For number crunchers, especially signal processing. Needs clear thoughts before, possibly at a university. Then, easy silicon. Bit transposed copy, Jul 06, 2016 5:05 pm, search "transposed copy". Mostly for databases. Needs thoughts before. Then, easy silicon. Flash chips with big throughput, 01 May 2015. A need, not a solution. Flash chips close to the computing nodes, with ports faster than Usb and Sata. For server machines and also number crunchers. A task for the Flash company. ---------- Stacked chips Adaptive connections accept misalignment, 08 and 23 February 2015, search "adaptive" (not only chips). For any Cpu, Gpu, gamestation, database, web server, number cruncher. Hardware development at the silicon design company. Optional upsized proof-of-concept at any electronics lab. Capacitive connections, Nov 12, 2015 2:47 am, search "capacit" (not only chips) For any Cpu, Gpu, gamestation, database, web server, number cruncher. PhD thesis exists already. No fine lithography, hence by any semiconductor lab, including equipped university. Connections by reflow accept misalignment, search "reflow". Nov 12, 2015 2:47 am, details 27 December 2015. No fine lithography, hence by any semiconductor lab, including equipped university. ---------- Software OS subset for small unit Dram, 13 September 2015. A need, not a solution. Database machines can have a unit Dram even smaller than present supercomputers. Usually done by the computer manufacturer, could be a collective effort too. Lisp, Prolog interprets, inference engine for small unit Dram, 07 December 2013. A need, not a solution. ---------- Boards Data vessels, 08 February 2015, search "vessel". By any electronics lab, or the Pcb company. Pcb with more signals: denser or more layers (or bigger). A task for a Pcb company. ---------- Machines Crossboards, 01 February 2015. For most machines with several boards. Electrical engineers, possibly with a (opto-) chip company, shall bring throughput. Optical board-to-board connectors, 02 February 2015 and 22 February 2015 - 12:47 AM, search "optical link". For most machines with several boards - but consider capacitive connectors. Needs some optics and some fast electronics, possibly together with an optochip company. Capacitive board-to-board connectors, 08 February 2015, search "capacitive". For most machines with several boards. Proof-o-concept by a skilled and equipped electronics lab, then chips by semiconductor designer and manufacture. Flexible cables with repeaters for many fast signals, 02 December 2013. For every machine except the smallest ones. By a skilled and equipped electronics lab together with a manufacturer of flexible printed circuits. Cable to board connectors by contact, 02 December 2013. For most machines with several boards - but consider capacitive connectors. Needs skills for mechanical engineering and fast electronics. Wider so-dimm-like connector, 18 October 2015 - 01:25 PM. For Pci-E boards, maybe others. Development by the connector manufacturer, needs skills for fast electronics. Capacitive cable to board connectors, Nov 12, 2015 1:49 am, search "capacitive". For most machines with several boards. Almost the same development as the capacitive connections between chips. Superconducting data cables, 02 December 2013, search "superconduct". For many-cabinet machines. Needs skills for superconductors, (printed?) cables and fast electronics. Insulating coolant, 15 November 2015. Chemistry lab.

I propose a bit transposition capability to take advantage of a processor's ability to make logic operations on 32, 64 or more bits at a time. Some applications, especially databases, must compute bitlogic operations on many items, but the homologue information bits are often spread as one per item (example: item for sale is new with tag, new without box, refurbished, used) while bitlogic needs them grouped in one word. So the instruction would perform Destination [word i, bit j] = Source [word j, bit i] on 64 words of 64 bits for instance, prior to the sequence of bitlogic operations that filters the items through a set of conditions, and possibly after it. The bit transposition would nicely combine with the "scaled copy" I already described http://www.scienceforums.net/topic/78854-optical-computers/page-2#entry778467 The scaled copy extracts the bit fields of a group of items and packs them in consecutive words, then the bit transposition puts homologue bits extracted from varied items in one word, ready for parallel bitlogic processing, after which a bit transposition and a scaled copy can write the processed bits to the items when necessary. One operation could combine the scaled copy with the bit-reversed copy, but I don't feel it vital. The execution unit could hardly shuffle so much data, but the Dram or the datacache can. It could then be a transposed copy instruction similar to the already described "scaled copy" and "bit-reversed copy", to be done between address areas corresponding to variables named by the source program, which would then care about data coherency as it has the necessary information for it while the hardware has not. Here too, the cache or Dram must receive and execute more detailed instructions than read and write, which is easier when they're linked at manufacture. Transposing 32 words * 32 bits or 64 words * 64 bits means 128 or 512 bytes, an efficient size for data transfer between the Dram and the cache. For words of 256 or 512 bits, do it as you can. Data areas don't always start and stop at multiples of 64 words, and memory page protection will meddle in too. I happily leave these details to other people . Solutions exist already for vector computers. Marc Schaefer, aka Enthalpy ================================================================= I suggest a wide cascaded logic operation that operates on many independent bits in parallel, for instance the word width of the execution unit, and computes at once a small chain of logic operations over a few registers. It can be similar and complementary to the cascaded logic operation I aleady described : http://www.scienceforums.net/topic/78854-optical-computers/page-3#entry854751 and following The reverse polish notation and an implicit stack simplify the execution; Four bits can encode the operations And, Or, Eq, Gt, Lt and complements, plus Push, Swap, Nop... Three or four bits can designate the successive source registers (rather than the source bits for the previous cascaded logic) The logic expression to parse a database isn't known at compilation, so the operation follows a computed data rather than a set of opcodes. For healthy context switching, some general registers can hold this information about the source registers and the chain of operations. For instance, one 64b register can indicate 7 source registers among 32 coded on 5 bits plus 7 operations coded on 4 bits. This seems enough for a simple low-power processor that specializes in databases. Or one 64b register can indicate 16 source registers among 16 coded on 4 bits, and an other register indicate 16 operations coded on 4 bits. This fits the consumption and complexity of a number cruncher better. The throughput of the Dram and cache can be a limit. The "wide cascaded logic" operation combines nicely with the "transposed copy" and "scaled copy" operations. As the resulting bitfield can indicate which database items to process further, and the wide cascaded logic screens the items in less than one cycle each, one more instruction could usefully indicate where the first 1 bit is in the result and discard it. Some Cpu have that already. Marc Schaefer, aka Enthalpy

Yes, that's it. This is difficult for the tool because - It must fit in the curved groove it cuts - The chip must come out despite the groove is curved. If you can make a shoulder at the cylinder instead of a groove, and then an other shoulder at the head instead of making it flat, this step of machining is easier. The O-ring then fits between both shoulders. Whatever the design you choose, mind at what side of the ring the sitting plane of both parts is: it must retain the ring pushed by the pressure. And of course, don't forget the proper screws and pre-tensioning. The screws must press the head stronger than the fluid will: it's not just a matter of resistance, but really of pre-stressing - or else the O-ring gets extruded. At a past employer, we had 24mm screws all around a cylinder, but bigger is often necessary. One practical limit is 16mm (100kN), the maximum possible to tighten with a simple wrench.

Here are optimizations for a pressure-fed stage with wound graphite tanks. These apply to a "sailback" first stage with a graphite sandwich (it works for raceboats) cylinder holding the tanks. Helium from a high-pressure tank at oxygen temperature (heat pipe?) tops each propellant at its temperature all the time. The chamber and propellant pressures drop *0.45 at the end as does the thrust. The nozzle expands to 0.6bar at the beginning. The stage provides 4000m/s vacuum equivalent. Composite plies work at 1200MPa at all tanks, the cylinder weighs 10kg per ton of propellants, the engine 20kg/t, the paraglider and undetailed items hers 15kg/t. The injectors are 88% efficient, vanes 95% when not throttling additionally. The best chamber pressure is 49bar at beginning with Pmdeta, but 45bar is as good and saves helium and graphite. Logically more than 36bar, the optimum with heavier steel. Pmdeta remains an excellent choice with graphite: hard to light, nearly nontoxic, mass-available and cheap, good Isp, and its nitrogen saves cold oxygen hence helium and tank mass. Bulky and cold methane is the worst performing with graphite too. Flammable spiropentane, azetidine and cyclopropane would but outperform Pmdeta: 3.4%, 2.1% and 2.1% more payload per stage. This makes 10% more mass in Gto, not worth the risk. Boctane (cyclobutylcyclobutane) is as good as Pmdeta, Rg-1 and Jp-10 are worse than Pmdeta and no better than the cheap cis-pinane. Strained amines like diazetidylcyclopropane are as efficient as cyclopropane, hard to light, and easier to produce than strained hydrocarbons. They save helium and graphite too. Best improvement to Pmdeta. Trimethyltriazinane and the viscous Deta are 1% less efficient than Pmdeta, and they save helium and graphite. A eutectic with Pmdeta would be nice. A first stage with 150t propellants would carry 1.8t helium (36k€ in 2015), still there at the end of propulsion and possibly when the stage lands at the coast. A graphite pressure-fed first stage delivers 4000m/s easily. 5000m/s are reasonable, 6000m/s overstretched and an Ssto impossible. This tops steel tanks by 1000m/s to save one stage or enable other stage combinations. The construction is already described for light tanks and pumped propellants: http://www.scienceforums.net/topic/60359-extruded-rocket-structure/page-3#entry917836 The tanks are just thicker here. Here's an example of arrangement - some tanks could be oblate or toroids at a short stage: The nozzle of a second stage can expand to a lower pressure, for instance to push 180kN in D=2.2m with Pmdeta, and then 25bar in the chamber is optimum as it lightens the tanks, but 20bar is nearly as good. With the smaller engine weighing 10kg per ton of propellants, the cylinder 10kg/t, undetailed 10kg/t without paraglider, and helium filled to 165bar, the stage without electronics weighs 54kg/t, wow. Expansion to 2.2kPa achieves Isp=3537m/s=361s, wow again. 5500m/s is easy for such a stage, 7000m/s reasonable and 8000m/s overstretched. Marc Schaefer, aka Enthalpy

Welcome, Adze! I measured it for glycerine, and my opinion is that the flow of air above the liquid surface determines the rate - unless the absorbent is very inefficient or saturated. And even if the air had a flow fast and turbulent enough, then the spreading of water molecules in the liquid would be the limiting factor, which itself depends on flow and turbulence of the liquid rather than on its hygroscopic properties. For a powder, the grain size and the way air flows (Lifting the powder? Gently through the powder? Over it?) would be determining. So the rate of absorption would not be an intrinsic property of a good hygroscopic substance. NaCl is inefficient as a hygroscopic substance, while KOH is very efficient (but has drawbacks). With ethanol, you'll get more vapour in air than humidity in alcohol. Why shouldn't you choose normal compounds like glycerine, PEG, calcium chloride?

For having done it, I know that one has plenty of time to remove the aluminium.

Hi Externet, It depends on where your O-ring shall seat, and unfortunately I lack English vocabulary here. If you have freedom in the way you split the parts, it may be possible to have only shoulders in all parts, which is easy to machine. Better solution, even if this needs more parts or more O-rings. When you need a groove and the parts are in an other, the proper tool does it if the part fits in a turning machine; noncylindrical parts instead are machined by milling, but usually not with a milling cutter: a fitting holds an eccentric single-tooth tool like this https://en.wikipedia.org/wiki/File:Universal_Plan-_und_Ausdrehkopf_von_Wohlhaupter.jpg I didn't find the eccentric adapter's English name. Wohlhaupter in French like the name of a company, and Ausschlagfutter in German. Maybe a boring head. If the parts are butt and you need a groove, you may still try the eccentric tool holder, but the working conditions are horrible for the cutting tool. It's better to use just a usual narrow milling cutter moved in a circle by a CNC milling machine. Though, an O-ring demands smooth surfaces, which isn't automatic with CNC machines. As well, too narrow milling cutters are fragile. With a narrow milling cutter and without CNC, one would have hold the part in rotating vices (approximate name) in the milling machine's table. One hour to half a day adjustment time. Don't forget to specify the tolerances and the smoothness of the groove in a drawing, because O-rings have special needs, indicated by their manufacturer in the catalogue. Catalogues of O-ring manufacturers often propose design variants for the grooves, and experts at the manufacturer can check you design and give advice. Exactly this point in a design can cost one minute machining and work properly, or cost half a day and fail, so invest the necessary engineering time.

Dear friends of music, arts, and all inquiring minds! Here's a nice web address to hear a celesta https://www.celesta-schiedmayer.de/en/celesta/celesta-audio-samples/ at the website of one manufacturer - there aren't so many. Also pictures and explanations there. In short, the celesta has a keyboard and hammers like a piano to strike high-pitched metal bars placed over tuned air resonators. Many symphony orchestras have one, but it's not very common. One other manufacturer http://www.glockenspiel-lippert.de/celesta.html and Wiki claims Yamaha produces some too. A third-dozen more companies have existed, including the inventor's one, Mustel. Some instruments subsist, from Jenco among others; you may observe that the design differs much among the manufacturers. Enjoy!

Decades ago I had an equivalent containing only NaOH and Al, no idea if it's available where you live. After dissolution, Al can be removed by filtering.

The usual situation is that a gamma photon produces a positron-electron pair near a nucleus. The strong electric field (not gravitation) is necessary, and this is much more efficient with a neavy atom than a light one. The energy of a photon depends on the observer, that's the Döppler effect (the gravitation potential has an influence too). Though, the photon's energy won't get zero nor infinite whatever the other observer's speed. The photon keeps its speed versus any observer and a finite energy, consistent with zero rest mass. I have supposed very vaguely that photons of high energy arriving at a horizon event might help the creation of new particles, a process more efficient than Hawking radiation, but this is uneducated guess. Translate: not mainstream physics. Or shorter: probably crank. http://www.scienceforums.net/topic/84942-seeded-hawking-radiation/

I may have been fooled because the strong force increases with the distance. So, would I understand you properly by putting that way: The confined quarks have a (always positive) kinetic energy tending to expand the nucleon, but the (positive and increasing quickly with distance) strong force keeps the nucleon small, an their sum is positive? Then, the quarks and gluons wouldn't even need a "rest mass" (whatever this may mean here) to achieve the nucleons' mass.

In addition, a thermometer would tell that iron gets hotter in sunlight than wood or plastic. The heat emissivity makes a difference, though in our atmosphere, it's not the most important.

The binding energy is negative and reduces the particles' mass. Since particles have a positive mass, I expect other contributions to outweigh the binding energy. Or? And does the mass of all particles rely on the Higgs mechanism, or only of a few of them?

I hadn't search for them because I use this data regularly and know it by heart. Here's a doc from Fuchs for titanium alloys. In German, MPa means MPa, mm means mm, and so on. The one alloy widely available is TiAl6V4 in state "geglüht" or annealed, offering 830MPa yield strength. The others are rare and made on order; Fuchs only indicates 1105MPa yield strength, up to maximum 75mm thickness - but I've already seen 1200MPa. Ti_Fuchs_Warmausgelagert.pdf For a doc about Maraging steel, search Vascomax C-350 Vascomax C-300 yield strength is 2344MPa and 1999MPa. These things do exist (for decades), I used them. They're tough, weldable, can be machined prior to hardening (and after to some extent). As opposed to ledeburitic steel, parts of Maraging steel can be designed just like tempered steel. Other, cheaper alloys may be less tough or get strong internal stress at hardening, which then limits the parts shape.

Is there such a rest frame?

OK, I was wrong. Essentially outdated. https://en.wikipedia.org/wiki/European_Parliament#Legislative_procedure The Parliament can veto many proposals by the Commission, but it can't decide alone nor take the initiative, in most cases. Though, I suspect that Wiki's description refers to regulations, laws and directives. There must be other institutional acts for which the Commission needs no approval from the Parliament and can't be vetoed. ======================== "Referendum not democratic": Bypassing representatives is an improvement of democracy. If half of a population doesn't vote, they should blame themselves and nobody else. Anyway, nobody should suppose that those who didn't vote would have had a different opinion. Be reassured that the representatives don't understand the issues neither. This way of thinking is dangerous. I know very well that accepting a vote opposed to your strong opinion is hard, but it's the only way. Just consider that if some better-knowing person shall decide rather than the majority, you'll probably not be this person, and this person is very likely to decide what you dislike and what the majority dislikes. So, the proper way for democracy to work is that even when the people is wrong, the people is still right. ======================== I wonder about the EU import tax. It's not universally known, but pretty much every good entering the EU is taxed, by 19% if memory serves - a LOT of money. Presently, many overseas companies have some bureaus in the UK to receive the goods and sell or dispatch them in the EU. And since - please correct if I'm wrong - this tax goes to the country where a good lands first, it makes huge incomes for the UK budget. With an exit, these companies would reconsider their European location, and anyway, the tax would be collected by other member states. At least for that aspect (which doesn't compensate the loss of a strong and close partner), the Brexit would bring some advantage to potential entry and contact point countries: Netherlands, Belgium, Luxemburg, and because of its size, Germany.

The least volatile compound may deposit as a tight layer on the powder grains, preventing the evaporation of the more volatile compound. A parry is to heat the cylinder's end enough to evaporate both compounds. Thanks JC!