Almost forgot this one :)
Brendan McMonigal et al., "Alcubierre warp drive: On the matter of matter", Phys. Rev. D 85, 064024 (2012)
Abstract: The Alcubierre warp drive allows a spaceship to travel at an arbitrarily large global velocity by deforming the spacetime in a bubble around the...
Parthiban Santhanam et al., "Thermoelectrically Pumped Light-Emitting Diodes Operating above Unity Efficiency", Phys. Rev. Lett. 108, 097403 (2012)
Abstract: A heated semiconductor light-emitting diode at low forward bias voltage V<kBT/q is shown to use electrical work to pump heat from the...
The following circuit is given:
[PLAIN]http://img822.imageshack.us/img822/6369/image2lz.jpg
Switch S is closed until the charge q2 on C2 reaches its maximum, then at t=0 the switch is opened. Find q1(t).
Using Kirchkoff's rules I found:
EMF= (q1)/(C1+I2R
I2R= q2/C2
I1= I2+I3
In order to...