What is a justified way to visualize one-dimensional geometrical configuration of dust molecular clouds?

There are several papers which are using following formula (as shown in the picture) to calculate the dust mass (Md) of the dusty environments such as Nebula, loops etc in the ISM. The expression for dust mass shows that it depends on grain size, grain density and grain emissivity, here, for IRAS Survey, grain size = 0.1 micron, density = 1000 kg/m3 and emissivity = 0.0010 for 100 micron, respectively, are used. Are these constants same for AKARI and WISE survey too? OR, are there any other methods for the dust mass calculation using AKARI and WISE data? I would be very much happy to get your valuable suggestions. Thank you :)

This question is directed to observational astrophysicists. I am working on the radiation problem associated with massive star formation. I want to know if the opacity of the gas in molecular does vary with distance from the center of a molecular clouds. I see that in the literature this opacity is assumed to be a constant taking a value of about 20 m^2/kg. I will be happy to get an answer from you!

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What are the major unsolved theoretic problems on the astrophysical dust molecular clouds and their evolutionary dynamics?

What are the physical properties of the largest dust grain existing in astrophysical media?

I am interested in the motivated stability analysis of magnetized rotating spherical nonuniform inhomogeneous dust molecular clouds on the Jeansean scales of space-time. The components of the Lorentz and Coriolis forces are the complicating factors. Can anyone extend any help in terms of suggestion for simplification, or literature for execution?

When considering bending modes for linear polyatomic molecules containing hyperfine structure, how does increasing the vibrational state affect the various molecular parameters involved in calculating the hyperfine energy levels?

How can I access the daily dust data of Iraq for the statistical period 1986-2019?