A "surface grinder" is apparently a grinding wheel mounted for #machining precise amounts off of a surface (with a precision down to about 2.5 μm) on a part held with low-distortion means (typically a magnetic chuck) on a movable table. #manufacturing #hardware
More about #surface-grinder #manufacturing #hardware
you can move objects around surfaces by manipulating Chladni lines, including moving several objects at once. Up to six different motions from a single acoustic actuator. Research by Quan Zhou. #hardware #resonance
The Encyclopedia Britannica 1911 article on weights and measures; its section II, “historical”, seems to be the source for Adrian Mariano’s Assyrian cubit and other measures, including the susi. #metrology
A chapter from Livio Catullo Stecchini’s #ebook “A History of Measures”, based on his doctoral dissertation (sometime in the mid-20th-century?), about ancient #metrology and the #archaeology of Mesopotamia. The images are lost, but the chapter claims that the Sumerian cubit was close to twice 249.7 mm and was divided into 30 “fingers” or, I suppose, šusi, and that earlier Sumerologists who believed in a 16-finger #Sumerian “foot” were misinterpreting a single statue from a temple dedicated by Sumerian regent Gudea. Also he derives pre-metric European units of measure from Mesopotamian and Babylonian-Egyptian units.
a chart of different kinds of #adhesives #materials for #manufacturing
pcolormesh is the #matplotlib function for #visualization of 2-D arrays as e.g. pixels.
Meanings of “computation” in the theory-of-programming and theory-of-computation senses. “Machine and language models of computation differ so greatly in the computational complexity properties of their description that they form two distinct classes that cannot be directly compared in a meaningful way.”
control is a Python library for control systems (think PID control, BIBO stability, that kind of thing) based on the MATLAB control toolbox.
Milkymist developed a #hardware design language as a Python EDSL called Migen (or maybe “FHDL”, I’m not sure); it can be simulated directly or compiled to VHDL or Verilog, but not using a Python AST walker like MyHDL.
#pdf #paper on #energy-harvesting #hardware, suggesting using a buck converter to harvest more energy from a piezo harvester. By Ottman, Hofmann, and I forget.
for US$130 you get a 1-kg wood-burning campstove with thermoelectric generator #hardware to charge your cellphone
#pdf #paper on the physical properties of possible liquid metal coolant #materials for a nuclear reactor, including sodium, lead, and lead-bismuth eutectic.
#Autism makes it hard for other people to understand your emotions, even if they’re autistic too. #psychology