Recent content by gjfelix2001

Hi everybody... I want to solve the diffusion equation in 1D using the Crank-Nicolson scheme. I have two books about numerical methods, and the problem is that in "Numerical Analysis" from Burden and Faires, the differences equation for the diffusion equations...

Hi there... I have a differential equation with to terms: \frac{d[Ca2+]}{dt}=f\Big(\frac{3I_{Ca}}{z 4 \pi r^3 F}-k_{Ca}[Ca2+]\Big) I think that the first term converts the Ca2+ (density of?) current to mol units. But, where does it comes from? z is the valence; in this case of the...

RC circuit: is this the right equation? Hi everybody, I'm trying to solve the equation: I(t) = \frac{dQ}{dt}=\frac{Q(t)}{CR}-\frac{V}{R} in order to get this graph (V changes to simulate the pulse) [PLAIN]http://i.imagehost.org/0340/Respuesta1.jpg I'm not getting this response...

Hi everyone... I need to solve the differential equations of a RC circuit given a voltage and a current pulse. I have to get this responses: http://i.imagehost.org/view/0340/Respuesta1 I'm using matlab, with runge kutta. I've been solving the equations separately changing the initial...

Homework Statement Give the equations of motion of the following system: http://www.jelp.org/imagenes/mech.jpgHomework Equations So, i assume the following cases (the diagram i so deficient). 1) Black Point (x1) is fixed 2) There's a force applied at x1 (black dot) 3) The position of the...

Homework Statement In this problem I'm asked to give the differential equation of the mechanical system in the following diagram: http://www.jelp.org/imagenes/mech.jpg Homework Equations Once i understand the diagram, i'll get the motion equation by Newton or lagrange. But what is G...

Hi again, first of all i want to thanks the replies to my previous posts. Second... I'm looking for a paper about the GaP band structure. Actually i only need the band structure tu compare it with mine but i need the reference to that paper, can you help me?? sorry for my bad english by the way...

Hi, i can't understan clearly the Exchange-correlation term that appears in the develop of DFT. The only thing i know is that the first comes from the pauli exclusion principle, and the second from the quantum part of the coulomb interaction between electrons. Am i right?? but i wan't to go...

what does "band gap bowing" means? Hi, i speak spanish, and I've tried to translate the term "band gap bowing", but literally it doesn't have any sense. So, can anyone explain this term to me so i can translate it correctly?? Thanks a lot.

dipole torque problem.. Help please! Hi, the problem is: Show that if the force action on a dipole p placed in an Non uniform electric field is p\cdot \nabla E_{ext}, the torque acting on the dipole in this field is \tau =r \times (p\cdot\nabla E_{ext})+p\times E_{ext} where r is the...

Hi, i am looking for the following papers: L. Vegard, Z. Phys. 5 17 (1921); Z. Kristallogr. 67,239 (1928) Thanks a lot :smile:

Hello, i am looking for papers about GaN and GaP "history", i mean serious papers or sources, everything will be useful. Thanks. :smile:

Thanks, and help again :) Thanks a lot for this information. I want to read the article you recommend me, but it ask for a password, obviously i don't have one, so do you know another free source of information about this ? every website that has information or papers about this isn't free. I...

Hi, can anyone give me references about the Vergard's Law, i have heard about it through a couple of papers, but i haven't found a thing in my books. Where can i read about it? thanks