How to find Reduced matrix elements for the rare earth ion transitions?

Please help me to clarify doubts on it

06 July 2013 957 7 View

Physics: Why do we describe light by referring to its wavelength, but microwaves and radar pulses by referring to their frequency?

In physics, the description of the properties of light generally refers to its wavelength (nm), while in the range of microwaves and radio waves we refer to the frequency of a signal (e.g. kHz or...

03 March 2021 1,682 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

Why are the velocities so high in my Boussinesq approximation Fluent simulation?

Hello, I have a mechanism where air rises due to convective flows. In this simulation, nothing is driving the air except this. I understand that the Boussinesq approximation only works for small...

02 March 2021 4,910 3 View

Why almost every element would be metallized in sufficiently high pressure and low temperature?

(This statement is from wikipedia, BTW). What is so special about metallic bond that is limiting high-P low-T state of a matter (as long as individual atoms exist, not white dwarf of neutron star...

02 March 2021 3,309 2 View

What is the state of the drug inside solid lipid nanoparticles (SLNs)?

I am a little confuse with the mechanism of solid lipid nanoparticles (SLNs). The main point of encapsulating drugs into SLNs is because some drugs have low solubility in water. Therefore, SLNs...

01 March 2021 3,703 3 View

What is the density for pva electrospining?

I'm Juan Carlos, a high school student who is working with electropinning, I made an electropinning machine with a 21g needle and a 30kv high voltage source and the distance between my needle is...

28 February 2021 298 3 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

Should we reduce the standard unit of length to 0.31951540592 meter ?

The reasoning behind this question is to align the ratios of the proton potential in energy per charge to the speed of light in distance per time. As these two dimensions appear to be related,...

27 February 2021 947 7 View