Alts (mostly for modding)
@sga013@lemmy.world
(Earlier also had @sga@lemmy.world for a year before I switched to lemmings)
there is also energy released in reaction, that can cover for decrease in surface energy and also the energy of dissolution (think of copper sulphate crystals forming). Energetically it is possible. Problem is find the particular system which checks all boxes
Sorry, but I do understand this stuff, my bachellors is in materials science, I do not master this domain, but I at least understand the thermodynamics and solidfication okay enough. I know of bayers process, and I know it can not be used for 3d printing. What I am saying is
If something has very high enthalpy of formation, then end prouct is very stable - something I want for the end product (most ceramics have good enough stability for our needs).
usually activation energy required is very high - one of the best way to give activation energy is raise temperature. Problem with very high temperature is now the nucleation rate is very high (nucleation rate is rouply proportional to temperature difference between equillibrium temperature and temperature of process). If nucleation rate is very high, we will form snow like crystals - fluffy (not dense), so we can not really use it to build layers above.
If we find something with very low activiation energy (which the CaCO3 formation has (reasonably low compared to other ceramics, that is one of th ereasons why we use it as a primary test for verification) then we can perform reaction at very low temperature. And growth rate is exponential decaying with temperature (the mobility is exponential with temperature) so growth would be prefered and we will form large crystals.
another thing to control is directionality - if we can have direcctional solidification (something like silicon manufacturing) then we can perform 3d printing, otherwise things will grow accordingly to minimise the surface energy (everything technically does, but what I mean is, if there is significant anisotropy in growth rate along particular direction we can use it))
I may be wrong here, I definitely have not given it much thought, but I don’t think I am absolutely off the track. It doesn’t also help that these days I am not pursuing Material processing at all, so I may have forgotten a few details, If I still have something wrong please correct me
ceramics kinda don’t shrink. They do shrink, but CTE is very low (generally due to very deep potential wells). And assume we are at low temperature crystal growth range, we would see big crystals, with relatively low internal stresses.
that is also a problem i thought (last line of last issue). What I was thinking was that if some research group has already taken this, where for example the crystal structure has really high enthalpy (something like Al2O3) but also low enough activation energy, then at very low temps, the reaction will drive itself, and we can use fans to evaporate. I am sure there must be some goldy-locks zone somewhere
I know about this, and this is the very source of my idea - basically thinking why dont we 3d print cement. Then realised cement or concrete are way too complex structures, lets just consider slaked lime to lime
yes and no, turning sand to glass requires temperatures in ball park of 1600 C (close to glass transition temperature of Silica), even with mixing of stuff that will go to down to something like 1200, and the ones I found online were not going to that temperature. At lower temperatures, free silicates start to grow the existing silicate chains, knocking water out. Any glazing observed would be because now we are moving towards a more smoother surface (as in, due to solidification). There plenty other side reactions, but basically at low temperatures, we can only have chain growth or initiate (at this low temperature, initiation is also very slow, and growth is the dominiant mode).
what kind of ceramic prints? the clay kind or the kind I am looking for?
yes i did think of that, but that is (i think) a smaller overall effect. If tip has solidification, the edges will grow wider, and drop will get a much larger surface to form, and if i remeber correctly, for a drop to stable, it has to be basically be like a hemispherical dome, and base radii growing means a larger drop.
I just gave it up 1 day. No life changing event, no bad experience, just a shift in perspective happened, and I basically realised that I did not really need a god. I still practice some things which were part of my religious activities (donating, or serving others), but that is more of general good citizen thing rather than being religious
no, afaik kilning of clay is basically baking clay (I think that is why we have “brick kilns”) that is basically drying of silica (or some secondary or tertiary silicate chains, or aluminate or borate chains) - removal of water, which is techinically a chemical reaction, but the boring kind. What I am thinking of baiscally making the silicate chain
they are effectively GPUs
context please, I am an uneducated delinquent
used to just view reddit stuff earlier (without account due to privacy reasons), but decided to stop that during reddit API changes, and then learnt about lemmy, and been here since then (not with a single account, had a old account which I deleted this year when i switched the base instance)
There is no 1 single answer. Just do it when you (and they) feel comfortable. Considering from a practical standpoint, do it when both of you are comfortable in sharing their chores, and having dull moments in life.
Although I would like to ask, Why?
Hello from India.
in Hindi (transliterated, because not same script) - Namaste
You can do 2 things - install a custom rom or de-enshittyify
From what i got from checking - there is not any rom already present, you can try to make one yourself, but that is a hard process
to de-enshittyify - you can start with UAD https://github.com/Universal-Debloater-Alliance/universal-android-debloater-next-generation.
first boot into phone (and dont connect to internet) and enable dev mode
then connect to desktop and open UAD, and it will give a long list apps which you can consider from removal (with deifferent degrees of recommendations)
you may also disable remove google play services at your risk (google apps, and banking stuff would not work, but better battery life and privacy)
after doing this, also remove any xaomi skin apps (can be done with UAD, in case it does not find anything, check the unknown section too) (phone, sms, message, …) these are usually forked from aosp, but with added “features”
replace these apps with fdroid equivalent (a good family of apps is fossify https://www.fossify.org/, and also use newpipe)
I am a bit experienced, so I can do it all in 1.5 hours, if you have not done this before, maybe 2-3 hours, and you will have a clean phone, largely devoid of closed source apps
I have recentlly created a data directory in my home dir, and moved almost everything I need to it. Even configs and program data are in it somewhere I find ok, and symlinked to the xdg dirs (I know i can make my new location the xdg dir for config and data, but this way I selectively add stuff to my now main config, so it remains more pristine)
In case you want to look at my config https://lemmings.world/post/21375035/13799657
A(dissolved) + B (gas) -> Delta (energy released) + C(precipitate)
since a was dissolved - there was some eenrgy of dissolution, now that there is a precipitate (and lets for simplicity assume Ksp = 0) then there is some energy required to create this surface.
for reaction to be energetically favorable (Gibs free energy, so entropy is also accounted)
abs(Delta) > abs(dissolution energy) + abs(surface creation)
this is going to maintained always. Now if Delta is very large reaction will almost run to completion (provided activation energy is given, lets say in form of temperature or mechanical agitation to increase the reaction probability of A and B)