My Frame of Reference

Tuesday, February 12, 2013

Li-ion battery issue of Boeing's Dreamliner 787

Santosh KC writes about a recent incident involving Li-ion battery in the Boeing's 787 Dreamliner ...

Boeing 787 Dreamliner is supposed to be one of the best planes in terms of its design, fuel efficiency and advancement of the technology. Everyone understands that every plane requires battery for backups or some electrical applications. However, the Dreamliner uses the Li-ion battery based on Lithium cobalt oxide (LiCoO2) extensively. It is because it is designed in such a way to use electrical signals for control system unlike the earlier planes with hydraulic control system. All 787s have two Li-ion batteries weighting around 63 pounds, compared with 106 pounds for nickel-cadmium battery in 777s, and holds electric charge of 65 ampere-hours, compared with 47 ampere-hours for 777 battery and measures 8.6 inches tall by 11 inches wide in dimensions... Overheating and catching fire by Li-ion battery in laptop, smartphones and electric vehicles has already been reported in many instances. However, such issues were not reported in aircraft because the Li-ion battery was not used for the electrical system in the planes to the extent as in Dreamliner.

Li-ion battery issue in Boeing’s 787 Dreamliner

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Monday, February 11, 2013

Linked profile, 200 millions and top 5% views

Recently I received a Linkedin message, stating that my profile was among one of the top 5% being viewed in the network. With about 1 profile view per day, on the average, I am guessing that you may also have received one... or will be getting one.
Here are my stats:

The stat went nicely upwards after this paper was online:
"Estimation and Bias Correction of Aerosol Abundance using Data-driven Machine Learning and Remote Sensing"
(This was presented in CIDU 2012, in Colorado; available here at ieee site:
http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=06382197

Anyways here are two links that you will get if you get the email about 5%:
http://www.linkedin.com/200million/

http://blog.linkedin.com/wp-content/uploads/2013/02/200M_Milestone_Final.jpg

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Tuesday, February 5, 2013

Domain Theory of Bird's Orientation ? #Fun

Does a bird have any preferred direction or orientation while lining up on the wire?

Well, look up the wire, in the morning or evening time when they are lined up for social gathering. They remind me of the domain theory of magnetism. Or rather the spin-spin coupling of the Ising model. The Ising model consists of discrete variables that represent magnetic dipole moments of atomic spins that can be in one of two states (+1 or −1). The spins are arranged in a lattice, allowing each spin to interact with its neighbors. Similarly, the interaction between these birds can not be more than one bird distance away on both sides! Since most of them tend to be aligned, the awkward amount of energy that they need to stay in reverse direction should be too high.