Answer:
the answer is below
Explanation:
a) The conductivity of graphite (σ) is calculated using the formula:
where f = frequency = 100 MHz, δ = skin depth = 0.16 mm = 0.00016 m, μ = 0.0000012
Substituting:
b) f = 1 GHz = 10⁹ Hz.
I think the answer is B) 1 a.m. and 5 a.m. I very sorry if it is wrong plz let me know if it is wrong bro thankx
Answer:
A selective surface with large absorption for solar radiation and high reflectance for thermal infrared radiation was produced by use of surface oxidation of stainless steel. The surfaces were studied for use with concentrated light in a solar power plant at temperatures of 400°C and higher.
In order to investigate the relation between surface treatment and optical properties, stainless steels (AISI 304 and 430) which were submitted to different chemical and mechanical surface treatments, were used. To increase the spectral selectivity, these surfaces were treated in air and in vacuum at different temperatures and times. The optical properties of these films were investigated. Visual and infrared spectral absorptances were measured at room temperature. The thermal hemispherical emittance and absorptance were obtained by a calorimetric method at 200°C. It was noticed that these chemically and mechanically treated stainless steel surfaces have good spectral properties without further oxidations. This is very important for high temperature uses. The best values are found for samples 7 and 8 under vacuum and air. These two samples with mechanically ground surfaces retained their selectivity and specularity after several hours oxidation. One can conclude that the surface ground treatment confers good selectivity on the steel surfaces for use in concentrating solar collectors with a working temperature of 500°C.
Sample surfaces were subjected to long temperature ageing tests in order to gain some idea of the thermal stability of the surfaces. The results promise better-performing surface and the production of durable selective finishes at, possibly, lower cost than competing processes.
Explanation:
Answer:
yes
Explanation:
blueprint of the construction is a prediction of project its is slightly auto cad
Answer:
0.067wc
Explanation:
The formula is actual static pressure loss = (total equivalent divided by 100) multiplied by rate of friction
We substitute values
actual static pressure = 0.1
Total equivalent length = 150 ft
0.1 = (150ft/100) multiplied by Rate of friction
Friction rate at 100ft = 0.067
So we have that the required friction needed is 0.067wc
