Recent content by gjfelix2001

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    Is there more than one Crank-Nicolson scheme?

    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...
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    Calcium current to amount of substance units (mol)

    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...
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    RC circuit differential equations

    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...
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    RC circuit differential equations

    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...
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    How Do You Model a Damped Harmonic Oscillator with External Forces?

    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...
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    What is the Differential Equation for This Mechanical System?

    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...
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    GaP Band Structure: Find Paper & Reference

    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...
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    Understanding the Exchange-Correlation Term in Density Functional Theory

    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...
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    What does band gap bowing means?

    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.
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    How Do You Calculate Torque on a Dipole in a Non-Uniform Electric Field?

    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...
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    Searching for L. Vegard & Z. Kristallogr. Papers

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

    Hello, i am looking for papers about GaN and GaP "history", i mean serious papers or sources, everything will be useful. Thanks. :smile:
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    Vergard's Law Help - Get References & Read About It

    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...
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    Vergard's Law Help - Get References & Read About It

    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
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