Can i use a non uniform stiffness tensor in COMSOL ?

Hello, I want to simulate the propagation of some guided waves in plates, with spatially dependent stiffness tensor. Can do that with COMSOL. Thank you in advance, I am new to COMSOL, and I...

31 December 2019 7,520 1 View

What is the magnetic field due to a moving current element ?

Hello To start off, the question deals with non relativistic system. It is known that Biot-Savart law gives the magnetic field at position r (the position of the observer) , created by a...

08 September 2019 827 4 View

Boundary condition on a solid surface under traction/compression ?

Hello, I have a block of solid material in which an elastic wave is propagating. On one side of the block I maintain a static surface stress (the agent causing this stress is external to the...

06 July 2019 438 8 View

What is the induced EMF in a stationary coil by a moving current source ?

Hello, The real problem is : I have magnetic material (magnetized) that is deforming in time (let's say, because of vibration) with respect to the reference frame of the lab, I want to know,...

03 April 2019 2,808 3 View

Phase shift between, current, E field, and B field ?

Hello, I have a wire with AC current : ## Ohm's law gives : J = \sigma E J : the current density \sigma : the electric conductivity E : the electric field From this equation it is clear...

03 April 2019 5,542 3 View

How do we determine the number of electrons of an atom ?

Hello, Are we (me excluded) sure that an electron is a particle ? If not, is its nature "countable" ? Today if someone asks you to show them (experimentally of course) what is the number of...

01 February 2019 7,516 7 View

How does a static/moving electric charge maintain its field ?

Hello, Suppose I have a charge at rest, my question is, since the electric field of this charge will "go" to infinity for eternity, where does the energy come from to maintain that field. We all...

11 December 2018 4,481 20 View

How to invert the electromagnetic field to get the current source ?

Hello everyone Suppose I have the next example (see figure) : I have two experiments : I know the input current in the first coil, and from it I compute the induced current in the second coil...

10 November 2018 7,695 4 View

Does the motional electric field verify Gauss's Law ?

Hello, I have a problem understanding Gauss's law for electric field. I know that, if I have a distribution of static charges, the divergence of their electric field is equal to the charge...

09 October 2018 1,493 0 View

Magnetic but non conductive materials ?

Hello, I want to know, if there are materials that are magnetic but non electrically conductive. I already thought of Ferrit-NiZn, and some composites, however I wonder there are others. Thank...

09 October 2018 3,613 3 View

Could you recommend any books about Number Theory?

Beginner level books. High level books. Analytical Number Theory. Algebraic Number Theory. Combinatorical Number Theory. Books about partitions. Books about primes.

03 March 2021 7,174 5 View

Arena simulation - how do i model the following model in ARENA (see description) (new to ARENA)?

Hello, I'm fairly new to ARENA and I have the following problem: I have two queues in which, in each queue, a different order type arrives (both having an arrival rate of exponential 10). Order...

02 March 2021 2,431 3 View

How Relativistic effects is one reason for lanthanide contraction?

The Lanthanide contraction which is the decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, is due to poor shielding of the 4f...

01 March 2021 2,272 4 View

In Molecular Dynamics Simulation, how do I make changes to the force field according to my protein?

Hi In Molecular Dynamics Simulation, how do I make changes to the force field according to my protein? I got this error in the add-ion stage: Fatal error "./ amber99sb-ildn-HHH.ff / force...

01 March 2021 8,747 4 View

Is there a deep reason for using the squared modulus of the wave function as the probability density of the existence of the particle?

I think we were all surprised at the first time we got to know quantum mechanics that the squared modulus of the wave function is the probability density of the existence of the particle? The role...

28 February 2021 6,282 9 View

What is Flat Lens Antenna?

28 February 2021 5,433 3 View

Can impedance of antenna be less than 50 ohms?

I am simulating helix antenna in hfss, right now, giving excitation with 50 ohms port. When I see the results of Z parameter (real). It shows lower than 50 ohms. Do not understand, if it can be...

27 February 2021 4,218 7 View

What are the application of Fixed points thoery in Chemistry.?

It is said that fixed point theory has lot of applications not in the field of mathematics only but also in various areas. So I am looking for applications in Chemistry only..

26 February 2021 3,533 1 View

How to interpolate from a time-series database ?

Hi, I am having trouble with a problem, in the field of Optimal Control and the generation of optimal time-series. Let's consider a system, whose dynamics are represented by dx/dt =...

24 February 2021 9,105 2 View

How to constrain genetic algorithm input u?

My real system (buck converter) can only take an input of 0 to 1 (duty ratio) and I need to constrain the system so the controller action keeps within this bounds. How can I do this? The code for...

22 February 2021 2,125 3 View