#SEM #microscopy #introduction, covering issues like critical-point drying, field emission vs. thermionic, magnetic astigmatism, secondary electron noise, #vacuum, etc.
#fluidic #pump
#vacuum levels
#FIB #vacuum #machining #paper from 01999, “A review of focused ion beam milling techniques for TEM specimen preparation”, Giannuzzi and Stevie
Jeri Ellsworth’s work
#LinuxCNC on #Raspberry-Pi: “I am having problems installing rtai on a Raspberry Pi 4.” “RTAI is x86 only.” “Unlike most others I intend to use the base thread for my i/o, a latency of < 20uS would be desirable but not obtainable on this platform, maybe not any platform. Not using Mesa. Plan to build my own 48 pin optically isolated i/o and using stepgen.” Success not reported.
why #STM #microscopy is usually done at ultra-high #vacuum (picotorrs). Handy chart: roughly XHV = attotorrs, UHV = picotorrs, HV = nanotorrs, MV = microtorrs, rough vacuum = millitorrs. “At a pressure of 1×10⁻⁶ Torr the crystal surface will be contaminated with a monolayer of gas in 1 second.”
02014 #AFM #microscopy by “whoand” (Dr. Edwin (En-Te) Hwu, Institute of Physics, Academia Sinica, Taipei, Taiwan) under GPL. “I am pleased to share with you that the DIY AFM is reported by the latest Nature Nanotechnology 10, 480 (2015) that the DIY AFM is assembled by junior high school student...” Using store-bought AFM probes, though. Uses four piezo buzzers instead of cutting one into quarters like Berard’s STM. Uses FR4 (?) circuit board material for stiffness. Concrete block on bicycle inner tube for vibration isolation.
Maxim Shusteff’s 02006 #AFM at MIT. #microscopy
Crème fraîche can be made by souring cream with buttermilk. #recipes
#Charity’s retrospective #introduction to #observability in 02021. “The world doesn’t need another classification word for existing data types. And it doesn’t need another synonym for “telemetry” or “insights.” But there is a coherent set of practices that started to emerge about five years ago, in response to changes in how we build modern systems — particularly microservices. Those practices are a fairly discontinuous leap from their heritage of using metrics and logs. In fact, some of the best practices are exactly opposite those of monitoring, and the respective data formats used are entirely incompatible. Those practices do need a word.”
#observability: “Observability is a borrowed term from mechanical engineering/control theory. It means, paraphrasing: “can you understand what is happening inside the system — can you understand ANY internal state the system may get itself into, simply by asking questions from the outside?” We can apply this concept to software in interesting ways, and we may end up using some data types, but that’s putting the cart before the horse.”
Big Ball of Mud Pattern: “Keep It Working.”
“A #filesystem “change journal” and other topics” (in support of, e.g., backups) #Linux
"reflinks" allow you to make a copy-on-write link to a file snapshot; now supported both on #Linux (cp --reflink) and #MacOS (cp -c). Not supported by ext4fs I think. #filesystem
The #XFS #filesystem on #Linux has supported #reflinks since about 02016 (XFS 4.9), and btrfs for longer.
#thermodynamics properties of air.
#thermodynamics properties of steam, CO₂, R134a, etc., #CC BY-NC-SA
“Engineering #Thermodynamics: A graphical approach” textbook #ebook from 02010, #CC BY-NC-SA
WAITS files could be inserted into because they contained variable-length records, allowing the E editor to not bring the entire file into core or rewrite it. #PDP-10 #retrocomputing #history
#PDP-10 ITS images and instructions for #retrocomputing
#Babylonian #mathematics #history including multiplication #algorithm and stuff for quadratic and cubic equations
#avalanche transistor pulse generator #hardware for speed-of-light #metrology
sutta on sexual bondage in #Buddhism
#avalanche transistor pulse generator #hardware test in EEVblog #306
https://welcolab.wixsite.com/discovery/9-avalanche-transistors #avalanche transistor pulse generator info: “The LHC project Q-switch Pockels cell drivers use avalanche transistors... the favoured choice is usually either a string of expensive ZTX415 native avalanche transistors, or hand picked cheap ordinary 2N5551 transistors... The easiest way to build a high voltage avalanche driver is to use Zetex ZTX415 etc purpose designed avalanche transistors however they are very expensive, typically $10 each.” Extensive bibliography. Images not captured by archive.today, nothing captured by archive.org. #hardware
#avalanche transistor pulse generator #hardware
Jenny List’s 2N3904 #avalanche transistor pulse generator #hardware from 02016 based on Kerry Wong’s design
Kerry Wong’s “#Avalanche Pulse Generator Build Using 2N3904” #hardware
Spaced repetition learning with systems like AnyMemo, SuperMemo, Anki, and the #psychology behind it
#USA #politics #Trump’s "Truth Social", a GPL-violating Mastodon instance, defaced by pranksters
Dan Luu quoting Brian Marick claiming his aptitude for programming is low
Jef Raskin’s poem on “I before E”: “Education is forfeit for reinforcing such rules! / Sound a feisty reveille while eyeing the schools! / Neither will our heirs be agreeing to deceptions / Once seeing, herein, these sufficient exceptions:...”
Dan Luu on the benefits of being willing to look stupid. “I got pretty good at the game3 and my “one weird trick” was to think about what went wrong every time something went wrong and then try to improve.”