can you 'shine' candoluminescent materials coated on metals with induction? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: January 18, 2019, 10:52:41 pm
content: So we all know of the simple mantle lamp, like using Yttrium.Typically I guess they coat the mesh with its oxide and heat it with a flame. As pointless as it is, can you use induction or microwaves to heat some kind of susceptible matrix to turn it into a light source?

author: gibbled
author_rank: Regular Contributor
timestamp: January 19, 2019, 12:36:24 am
content: There's sulphur lamps...https://en.wikipedia.org/wiki/Sulfur_lamp

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 19, 2019, 01:08:24 am
content: No, it seems to be a radical catalysis process.You can certainly bulk-heat things, as above.Tim

author: coppercone2
author_rank: Super Contributor
timestamp: January 19, 2019, 01:55:25 am
content: It's not direct conversion of heat into light? It is a chemical reaction with the plasma?So you need a carbon laiden flame? (hydrogen wont work then, if you wanna be green or something)

author: cdev
author_rank: Super Contributor
timestamp: January 19, 2019, 02:20:31 am
content: Is this the stuff that glows when you're in the woods on a new moon and its pitch black?

author: coppercone2
author_rank: Super Contributor
timestamp: January 19, 2019, 02:22:05 am
content: i have no idea what you are talking about

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 19, 2019, 04:16:50 am
content: Quote from: coppercone2 on January 19, 2019, 01:55:25 amIt's not plasma, it's neutral. Radicals are molecules with unpaired electrons, which are typically very reactive.The molecular fragments in a flame are high energy and quite reactive indeed. To the tune of 3+ eV per molecule, hence the blue color of a flame.The white emission of these oxides seems to be a combination of catalysis, fluorescence, and non-black body emission spectrum.QuoteHydrogen may work. Hydrogen flames contain hydroxyl radicals. Evidently all hydrocarbon flames work, from methane up. Probably the presence of CH. radicals is sufficient.I wonder if others work, e.g. H + Cl (not that that reaction needs much if any catalyst to proceed), or O2 + H2S, or...Tim

author: cdev
author_rank: Super Contributor
timestamp: January 19, 2019, 04:44:32 am
content: Many people are familiar with the bluish glow emitted by the ocean waters when there is a so called "Red tide" - Which is relatively bright.There is also a form of bioluminescence which is found in woods - at least in California's redwood forests, and similar, you are only likely to see it in pitch darkness.Only in very dark woods will it be seen, pieces of wood will emit a cool bluish green light.Sometimes I've seen lots of these luminescent materials almost like a constellation of stars. The temperature conditions probably matter so its not present all the time. Only at certain times.Also, fireflies emit their bioluminescence. Thats much brighter than the wood kind. Very deep underwater there are a great many strange looking underwater creatures that utilize these kinds of light producing phenomena too. Especially fish that live in the very deepest parts of the ocean where sunlight doesn't penetrate.These kinds of glowing chemicals are produced by living cells and have been utilized by man as markers - the genetic codes to make cells glow in different colors are now used extensively as markers in biotechnology. For example, one use for these phosphorescent genes is to make it easier to count new cells that have grown, say in a healing response to an injury.https://en.wikipedia.org/wiki/Bioluminescence

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 19, 2019, 04:57:42 am
content: Quote from: cdev on January 19, 2019, 04:44:32 amI wonder if bioluminescent bacteria can survive on a rare-earth-oxide framework at 1750K? 🤔Tim

author: coppercone2
author_rank: Super Contributor
timestamp: January 19, 2019, 12:38:30 pm
content: 🤔what would happen if you add this stuff to black powder or thermite? I said black powder because it defiantly will have carbon. Or a flash powder with some carbon in it. Or silicon thermite.Maybe you make little spheres/balls/grains of whatever chemical composition is burning and coat them in a macoscopic YO2 cage so as they burn the stuff passes next to it?Maybe some kind of super signal flare (think for being lost at sea to signal plane) or light generator (maybe really slow burning bright) or decoy (something with military) thing can be made?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 19, 2019, 07:27:24 pm
content: I don't know that burning carbon would do it. CO does burn with a pale blue flame. Doubtful a powder or pressed composition would keep the REO around long enough to be significant. It would just cool down the composition. Much better to burn the metal directly, i.e. Al, Mg or Ti typically.I wonder if burning Mg vapor excites MgO. Sure seems like it. The vapor seems to burn orange (which may just be sodium present), but where it lights the oxide, brilliant white.Tim

author: coppercone2
author_rank: Super Contributor
timestamp: January 19, 2019, 10:06:47 pm
content: i don't think it would cool it down significantly. It would be a challenge not to destroy it IMO.

author: coppercone2
author_rank: Super Contributor
timestamp: January 21, 2019, 03:25:31 am
content: another idea, can you like, heat it with EM and then pass gas at a lower pressure over it?The idea being to minimize the amount of gas used. I don't understand the reaction. Do you need the stuff hot and the radicals will form or do you need the actual combustion reaction to be happening at the candoluminsent material matrix?

author: spec
author_rank: Frequent Contributor
timestamp: January 21, 2019, 07:25:12 am
content: Quote from: coppercone2 on January 18, 2019, 10:52:41 pmHi coppercone2Not sure if this is of interest/relevant, but you can illuminate fluorescent tubes with RF. We used to point aircraft radars at the hanger ceiling florescent lighting as a quick check to see if the radar was working.

author: rs20
author_rank: Super Contributor
timestamp: January 21, 2019, 09:38:29 am
content: Quote from: coppercone2 on January 19, 2019, 01:55:25 amI thoughtnothingcould convert heat into anything else. Some law of thermodynamics?A heat difference between two reservoirs can be converted to more useful forms of energy (Sterling cycle, etc), sure, but not just heat in one place like you'd be claiming here.

author: spec
author_rank: Frequent Contributor
timestamp: January 21, 2019, 09:51:47 am
content: Quote from: rs20 on January 21, 2019, 09:38:29 amI think heated material naturally converts heat to EM radiation, the frequency being proportional to the temperature.

author: coppercone2
author_rank: Super Contributor
timestamp: January 21, 2019, 01:26:42 pm
content: the (partial?) explanation is here:https://en.wikipedia.org/wiki/CandoluminescenceWhat is interesting me now is the idea of a minimum-fuel candoluminescence phenomena. If you get something hot enough, can you pass low gas flow/reduced pressure gas flow past the hot object to get the candoluminescent reaction?A experiment might be to take a light bulb apart, dust the filament in YO2 powder (mesh size?), and put it back together in a modified vacuum chamber and add various gasses to the chamber to see if the light output changes? then play with vacuum level, gas concentration and filament power.I actually don't know what a oxy-gas mixture does at reduce pressure. Will the light bulb explode? maybe you can get a non flame concentration going that still forms radicals? then the nature of the chemical reactions can be explored carefully.the other idea might be some kind of super bright flare.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 21, 2019, 10:13:17 pm
content: Quote from: rs20 on January 21, 2019, 09:38:29 amHeat is converted directly into light and vice versa, as black body radiation; the stipulation is that it must be in thermal equilibrium, so you aren't going to get any more intensity and wavelength than what temperature it's at.It's okay to have a non-ideal-black-body that emits most of its power in a narrow band, so long as its internal temperature is consistent with the peak intensity in that band, and the total spectral power is consistent with the law. This could be relevant in the present case, but doesn't seem to be. (There are lightbulbs under development which reflect IR back towards the filament, or which prohibit the filament from emitting as much in the first place, which do use this mechanism.)You could superheat a gas stream until it breaks up into radicals and plasma (this will be some thousands K for most gasses), which may exhibit catalytic behavior in the present case. But this basically forces you to use a flame in the first place (the flame temperature of most burning gasses is high enough, besides the chemical process at work), or heating the gas with a plasma discharge (like a plasma cutter or carbon arc torch).Tim