39 Matching Annotations
  1. Last 7 days
    1. Chemically, europium’s reactions are similar to calcium. It is used in some superconductor alloys and in television screens, where it produces the red color.

      europium has been popularly used for the red flash and light in smart phones.

    1. Alloys[edit] Antimony forms a highly useful alloy with lead, increasing its hardness and mechanical strength. For most applications involving lead, varying amounts of antimony are used as alloying metal. In lead–acid batteries, this addition improves plate strength and charging characteristics.[49][59] For sailboats, lead keels are used as counterweights, ranging from 600 lbs to over 8000 lbs; to improve hardness and tensile strength of the lead keel, antimony is mixed with lead between 2% and 5% by volume. Antimony is used in antifriction alloys (such as Babbitt metal),[60] in bullets and lead shot, electrical cable sheathing, type metal (for example, for linotype printing machines[61]), solder (some "lead-free" solders contain 5% Sb),[62] in pewter,[63] and in hardening alloys with low tin content in the manufacturing of organ pipes. Other applications[edit] Three other applications consume nearly all the rest of the world's supply.[48] One application is as a stabilizer and catalyst for the production of polyethylene terephthalate.[48] Another is as a fining agent to remove microscopic bubbles in glass, mostly for TV screens;[64] antimony ions interact with oxygen, suppressing the tendency of the latter to form bubbles.[65] The third application is pigments.[48] Antimony is increasingly being used in semiconductors as a dopant in n-type silicon wafers[66] for diodes, infrared detectors, and Hall-effect devices. In the 1950s, the emitters and collectors of n-p-n alloy junction transistors were doped with tiny beads of a lead-antimony alloy.[67] Indium antimonide is used as a material for mid-infrared detectors.[68][69][70]

      Potential uses in phone batteries and silicon wafers As semi conductors.

  2. Jan 2020
    1. a relatively poor conductor of electricity

      lead is a poor electricity conductor but good and used in phone batteries.

  3. Dec 2019

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  • Sep 2019
  • Aug 2019
  • May 2019
    1. It is a preferred component in lithium-ion batteries that power laptops, cell phones, and electric vehicles.

      what it's used for

    1. Arthur. The 16-year-old boy joined a group of young men who spent two months digging a tunnel 26m straight down before they hit a heterogenite vein. Now they descend into darkness each day, spending up to 24 hours at a time in narrow tunnels unable to stand, hacking away for cobalt. Every minute is suffused with dread, because many tunnels have collapsed in Kasulo, burying alive everyone inside.
    2. Elodie is 15. Her two-month-old son is wrapped tightly in a frayed cloth around her back. He inhales potentially lethal mineral dust every time he takes a breath. Toxicity assaults at every turn; earth and water are contaminated with industrial runoff, and the air is brown with noxious haze. Elodie is on her own here, orphaned by cobalt mines that took both her parents. She spends the entire day bent over, digging with a small shovel to gather enough cobalt-containing heterogenite stone to rinse at nearby Lake Malo to fill one sack. It will take her an entire day to do so, after which Chinese traders will pay her about $0.65 (50p). Hopeless though it may be, it is her and her child’s only means of survival.
  • Aug 2018
  • May 2017
    1. You carry some gadget, a phone or a watch or a pendant or an implant in your palm, and use it to animate any screen or surface you encounter.

      This would be useful in some situations, but maybe not when you don't want others to see what you are looking at.

  • Mar 2017
    1. blending technology with teachers to support interactive learning, exploration, and creation (instead of “drill and kill” techniques) leads to higher engagement and learning gains

      collabs with teachers

    2. digital technologies offer learners greater opportunities to be more actively involved in the learning experience.

      research opps.

  • Jan 2017
    1. His fix: Google Fi, a wireless reseller that piggybacks on several networks, requires no contract, and offers tight integration with Google’s other cloud-based products.

      Works with Pixel, Nexus 6P and Nexus 5X. Not for iPhones.