From experimental results, the hydraulic conductivity of a sand at a void ratio of 0.75 is 0.030 cm/sec. Estimate the hydraulic conductivity of this sand at a void ratio of 0.43. Use Casagrande and Kozeny-Carman relationships.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?