It seems, for a singular matrix H, C=[H,V] can not coomute with H and V simultanously. Is it right ?

08 September 2016 1,894 7 View

What is the distribution of partial sum in Poisson binonomial distribution?

04 May 2015 9,885 11 View

Why do you need imaginary numbers to describe Quantum Mechanics?

08 September 2014 8,928 68 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

What analysis to choose with a large neste dataset and clearly skewed or kurtotic distributions?

Hello! I have a dataset of n=3000 nested within 8 countries with approximately 200 or 400 responses in each country. I originally planned to perform multilevel modelling with 4 dependent variables...

02 March 2021 6,865 1 View

What is the characteristic length to determine the Reynolds number for the scattered turbulent fluid flow?

Dear all, I just saw this example in FB on the difference between laminar flow and turbulent flow. The flow from a pipe hits the sink and scattered. The flow from the pipe is characterized as...

02 March 2021 1,999 5 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

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

How do you mesh a thin solid in Fluent?

Hello, I have used the shell function on SpaceClaim to create thin solids for the model I am studying. These are contained within an enclosure for my study. I chose this approach as it avoids the...

24 February 2021 8,856 3 View

Are there any candidates for an Einstein's bare cosmological constant?

It is commonly accepted that General Relativity has its own 'bare' cosmological constant that contributes together with the cosmological constant resulting from vacuum energy density for an...

23 February 2021 5,448 8 View

No streamlines present in a small region inside a flow. This means exactly what?

No streamlines present means whether the flow is getting obstructed there and the velocity inside the region is zero? Or else, the fluid is trapped inside that region with a nonzero velocity?...

22 February 2021 5,249 10 View

The most suitable method to calculate the stress intensity factor in the presence of contact between the crack lips?

I'm trying to study cracked structures under a compressive load taking into account contact between the crack lips. I would like to know if the method of extrapolation by displacement remains...

21 February 2021 8,694 4 View

Can anyone help with an Accurate Diffuser Expansion Loss formula for rectangular shaped diffusers in turbulent flow regime?

I have tried Idelchik's Handbook of Hydraulic Resistance 4th Edition (2007 page 300) formulas and across some range the formulas are reported valid for, the law of conservation of energy is...

20 February 2021 2,504 1 View