"UNSCII", #viznut’s set of bitmapped #Unicode #fonts designed for #semigraphics.
#Vaxry thinks #D-BUS sucks because nothing on it conforms to any documented standard, so he thinks #hyprwire would be better. #IPC
Charlie Landau gave up on #CapROS in 02022 because of a lack of community interest. #capabilities #security
“#Hong-Kong pro-democracy campaigner and media tycoon #Jimmy-Lai has been found guilty of colluding with foreign forces under the city’s controversial national security law (#NSL).” #politics #china #news (from December)
#Adafruit says #Arduino’s new post-acquisition rules for the #SaaS they’re pushing users to are “incompatible with #open-source” because of course they are, that’s the whole point of SaaS, isn’t it? #Qualcomm #news from December
#D-star #path-planning #algorithms “widely used for mobile robot and autonomous vehicle navigation”
"D-star" #paper #PDF #path-planning
#faircompanies: “access to tools for the beginning of infinity”
#Samsung phones insert fake moon detail into photos that include the moon! #fraud #crime
#Ferrocement #dwelling building #video, part 7, framing the armature #toread
#solar #energy #sand-battery #energy-storage feeding 250 watts into a stove burner in a flowerpot full of (construction?) sand. #toread #video
#Ferrocement tank building #video #toread
#Beautiful #photos of atmospheric #sprites by Paul Smith in Oklahoma
#SIGGRAPH ’24 “thesis fast forward” half-hour #video covering 9 different #graphics dissertations.
Ruben Wiersma talks about applying 2-D neural networks on 3-D meshes in a few different ways, including three that you can pip install: deltaconv pcdiff gravomg.
Chenxi Liu talks about her #algorithms for analyzing vector sketches that artists can use to communicate visual ideas, so far apparently used only for sketch simplification and flood fill.
Rohan Sawhney talks about Monte Carlo geometry processing, specifically to solve PDEs on complex geometry without the volumetric meshing #FEM needs, using “Muller 1956”’s “Walk on Spheres” to interpolate boundary conditions into the interior of a region, using something that sounds similar to an SDF, though he doesn’t call it that; like a “ray tracer” for physics (versus FEM’s “triangle rendering”).
Silvia Sellán talks about faster computation of swept volumes, as well as some other 3-D problems like surface reconstruction; I don’t really understand the common thread between these, though she says it’s “uncertainty quantification”.
Xilong Zhou talks about how to acquire “materials” such as bricks, marble, or ceramic tile, from photos, to use their BRDFs or SVBRDFs in rendering, with some kind of #Bayesian approach.
“Hi, my name is Dr. Zachary Ferguson” talks about a new numerical method for #simulation that don’t experience numerical instability (explosion) when simulated surfaces come into contact and the time step isn’t short enough; it’s called "incremental potential contact", with a new smooth barrier function (with a singularity!) enabling Newton’s method with line search to solve the contact correctly, using continuous collison detection (“CCD”). He claims that his work has “sparked a revolution in physical simulation”, although if that’s true, I don’t know why he feels the need to introduce himself as "Dr. Zachary Ferguson", as if he were used to being ignored and dismissed.
Pascal Guehl [geɪł] talks about texture/material synthesis, what he calls “semi-procedural”, combining the advantages of “by-example” texture synthesis (trying to make things look like a photo) with procedural (adding up noise functions and frequency components). It works by finding the “closest procedural model” to a given example image. Looks really cool.
S. Mazdak “Maz” Abdulnaga talks about volumetric mapping for medical imaging, in particular by minimizing the distortion energy of a volumetric map (ℝ³ → ℝ³) between two target volumes; the energy is defined in a symmetric way, so it doesn’t change when you swap the volumes. For example, you can use this to analyze placental health during pregnancy by mapping 3-D MRI scans taken over time to one another. Other applications include improving texture transfer for surfaces.
Yiwei Hu talks about “efficient material authoring by inverse material modeling”, tackling the same problem as Pascal Guehl in more or less the same way, but using CNN #neural-networks and gradient-based #optimization; his approach seems to handle some cases like checkerboard patterns better than Guehl’s.
another #video #toread about aluminum-foil #batteries by #Thoisoi, who turns out to be Polish or Estonian, not Russian. He uses stainless-steel window screens as the cathode current collector, because it’s an #aluminum-air battery; in one case he adds a layer of graphite conductive spray paint to the screen. Additionally he’s going to use activated carbon for the cathode, sprinkling it on the epoxy-coated graphite-coated fine stainless-steel mesh, then pressing it in a jugaad five-tonne hydraulic press at 100° for 40 minutes, though he says you could just leave it for 12 hours at room temperature. In the end he has eight cathodes, four with a coarser mesh; the dry cathodes measure as only 8Ω or so on a non-autoranging multimeter. He’s making pouch cells with a food-bag hot sealer, which melts sheets of polyethylene (LDPE) together with a hot wire. His anode is 8-layer-thick aluminum foil. As an electrode separator, he uses a wet paper towel, and sandwiches the anode between two cathodes, I suppose to keep air from getting to it. Weirdly, he seals the pouch cell in plastic, so I’m not sure how the air is going to get to the cathodes. One of the cells uses 20mℓ o an electrolyte made from 5g NaCl and 5g NaHCO₃ #materials in 100mℓ of water, giving 0.75V which rapidly declines. On injecting 10mℓ 10% NaOH into the bag with a syringe, it perks up to 1.6V. Short-circuit current is 750mA, but he needs two in series (measuring 2.60V on the multimeters) to dimly light a red LED, suggesting an “internal resistance” of hundreds of ohms. With the NaOH he thinks its shelf life is only a few hours; his batteries were dead in four hours of playing his CD player.
I thought he was going to explain the results he got from different cathode geometries, but he never does. Also he never reports the power output of the battery or explains how the air is supposed to get in.
#Murray-Smith #video #toread on #DIY #manufacturing of metal-air #batteries
#video #toread on #DIY #manufacturing of aluminum-air #batteries
#video #toread where #Mr-Electron suggests #DIY #manufacturing of a 20kWh “lifetime battery” which is apparently encased in concrete?
#video on #bootstrapping aluminum-air #batteries with charcoal. Pounds homemade wood charcoal with hammer in a rag, then powders in a blender and adds (non-gelatinized!) cassava starch and water as a binder. Pounds this paste, still lacking any electrolyte, into a cut-off rectangular aluminum profile with a wooden ramstick, producing 7 bricks he sun-dries. Inexplicably he then puts the dried bricks into 7 aluminum profiles, using surgical masks as separators to prevent electrical contact. His current collector for the charcoal is a graphite rod from a carbon-zinc AA battery. Oh, and finally he adds seawater as his electrolyte. Measures 860mV open-circuit initially. Unclear how air is supposed to get to the cathode. Maybe he doesn’t know that’s necessary?
#video #toread on #bootstrapping aluminum-air #batteries
#JGC dissects disposable Fizzy Max III 60K Rechargeable Red Bull disposable vape #hardware and finds 800mAh LiPo #batteries, three microphones, and a microcontroller labeled “B0081S1” he wasn’t able to get into.
#paper on a guy whose stomach they had to remove at the Hospital Posadas because he tried to commit #suicide by drinking 500 mℓ of ferric chloride solution, which caustically etched his mouth, stained his teeth brown, and produced metabolic acidosis. They treated his acute iron intoxication with chelation therapy. Finally he died in the hospital 8 days after the operation, “product of a systemic inflammatory response syndrome (SIRS) due to respiratory complications in intensive care unit.” #medicine #materials #safety #toxicology
someone got ferric chloride burns on their arm, people tell them to not worry about the burns but fix their technique. #materials #safety toxicology
ferric chloride stains on skin last a couple of days, but in clothing are permanent unless removed with oxalate. #materials #safety
apparently in #medicine they used to use ferric chloride to treat poison ivy (dermatitis venenata) but it can permanently color the skin. #safety
#OED definition of “tinfoil”: “Tin hammered or rolled into a thin sheet; also, a sheet of the same rubbed with quicksilver, used for backing mirrors and precious stones; a similar sheet of an alloy of tin and lead, used as a wrapping to protect comfits, etc., from moisture or air.” So already 100 years ago in 01926 there was “tinfoil” that had other metals in it, specifically mercury and lead. The first citation is from 01467–8, “Tynfole”. #etymology