Robert Pogson

One man, closing all the windows.

Daily Archives / Friday, January 18, 2013

  • Jan 18 / 2013
  • 3

Lithium Ion Batteries in Boeing’s Dreamliner Didn’t Scale Well

Lithium ion batteries pack a very high energy density and when things go wrong a fire or explosion is the result. Tiny batteries are cooled by conduction to their surfaces in contact with other inert material. We have seen that go wrong on notebook PCs. Larger batteries have a lower surface/volume ratio making heating/cooling more critical.

Of course, Boeing wanted that high energy to weight/volume characteristic to increase the efficiency of the planes but they may have gone too far…

“The batteries at the heart of the problem, manufactured by the Japanese firm GS Yuasa Corporation, are essentially giant versions of the lithium-ion batteries used in cell phones and laptops. Like those batteries, the Dreamliner’s use a lithium-cobalt oxide cathode, which is "an inherently unsafe cathode," said Mark Allen, assistant professor of chemistry and biochemistry at the University of Maryland, Baltimore County. And in the larger form used by Boeing, they pose an even larger risk. When overcharged or damaged, they can become essentially a firebomb inside the airplane—one that burns without air and can’t be put out by usual aircraft fire suppression systems.

see Boeing’s Dreamliner batteries “inherently unsafe”—and yours may be too | Ars Technica.

  • Jan 18 / 2013
  • 0

FLOSS In Education Has Grown

Once again, a list has been created of useful FLOSS applications for education. Looking over it, I noticed many of the old standards such as and KOHA integrated library suite and GIMP image processor but was amazed at the depth of more specialized applications like classroom managment and school management. In line with my experience there truly is no reason to stick with Wintel in education.

“To compile the list, the Oxford-based organisation worked with the educational community and with the open source communities around many of the featured projects. The list contains several generic packages, Johnson writes, "but we’ve looked at them specifically in the context of their application to an educational situation, such as using an office package to author e-books."

see List of open source options for education published by OSS Watch | Joinup.

In small schools where I usually worked, FLOSS including GNU/Linux operating systems permit reliable and economical IT limited in function only by imagination of which there is no lack in the younger generation. In larger schools, FLOSS truly flies as FLOSS greatly increases productivity and lowers costs in bulk because there are no restrictive licensing/authentication schemes. Many systems don’t even require a full time IT person because the users can manage the software and only annual cleaning/inspection may require professional IT. In FLOSS, everything can be automated and remotely administered.