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Cake day: March 31st, 2025

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  • you see, you can be as wrong as you want to be. i won’t be teaching you middle school level chemistry against your will in a comment section. in concrete Ca2+ remains Ca2+, be it as hydroxide or carbonate or silicate and it cannot become reduced in normal concrete conditions and definitely it can’t be oxidized.

    The Calcium Carbonate degrades into Calcium Oxide

    no it fucking doesn’t, this is what happens when cement is prepared in a kiln. near surface of curing concrete calcium hydroxide captures carbon dioxide from air, then this crust of precipitate blocks it from moving deeper. which is why the rest of calcium hydroxide reacts with silica forming calcium silicate, which takes more time and is responsible for late strengthening. before you lost plot i was talking about oxidation of steel rebar, and it depends on many things, but for regular carbon steel if there’s no oxygen then it’s much slower. and because concrete is not very permeable to oxygen, there are all these engineering requirements about how deep rebar has to be. anyway, a little bit of vinegar would be just neutralized by calcium hydroxide from concrete and won’t do anything, a little bit of salt would be diluted massively and also won’t do anything, hydrogen peroxide would decompose because anything will do that




  • coated rebar isn’t, it’ll always get dinged somewhere. stainless is expensive and the real available scalable option is either galvanized or sometimes basalt fiber, or glass fiber but i’ve not heard about it too much. the most important factor in slowing down corrosion is how thick concrete layer is on top of rebar, because concrete is very slightly porous and will let oxygen in, but the thicker that layer is, the slower oxygen gets to rebar, then the slower corrosion is, and this means it takes longer for rust layer to grow enough for concrete around rebar to fail due to swelling, because rust takes more volume than corroding steel

    a bit of vinegar might strip zinc layer, but won’t do too much and definitely it won’t matter long term until most of zinc layer is gone. salt also promotes corrosion but this also depends on oxygen availability and won’t be too fast, it would only matter if there’s salt in concrete in large amounts









  • Yeah they’ll make medbeds any day now. Or maybe it’s for their internal use only, because they’ll noticed bubble and don’t like what they’re seeing. I wonder if they’re foolish enough to vacuum up all data from companies that used their chatbots to come up with something hoping that no one will notice

    Every single bit of that is so fucking stupid, they’re replaying crypto playbook 1:1. Spot an industry that they think they’ll manage in, then try to leech off of it in purest display of rentseeking imaginable, coupled with techbros folk belief that since programming is soo haard, then as they can do that they can do everything else too, all with no plan, no labs, no specialists onboard or faintiest idea what they’re doing


  • fullsquare@awful.systemstohmmm@lemmy.worldhmmm
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    22 days ago

    apparently it’s NFPA (american fire safety code) thing. these regulations might have been written when inhalational anesthetics were flammable. also keep in mind that people under anesthesia can’t move and that was also probably a factor


  • fullsquare@awful.systemstohmmm@lemmy.worldhmmm
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    22 days ago

    maybe it is for power cord specifically, and the same type is used for hospital equipment. some of (modern) anesthetics are powerful solvents but not particularly flammable. maybe it also has something to do with potential extra oxygen (or nitrous oxide) content in air







  • that destination could be still somewhere with access to stranded fuel and with access to other port, like oman, or they could perhaps truck it to yanbu and ship from there, but it doesn’t matter because price increase would probably need to be even bigger for it to make sense. facility would also need to run only on fraction of capacity, and there’s probably no point in that if you can’t export everything that’s made there. currently it might be damaged anyway. what i mean is, there are problems solvable by throwing money at them, but it’s probably not one of these