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:
15625 moles of methane is present in this gas deposit
Explanation:
As we know,
PV = nRT
P = Pressure = 230 psia = 1585.79 kPA
V = Volume = 980 cuft = 27750.5 Liters
n = number of moles
R = ideal gas constant = 8.315
T = Temperature = 150°F = 338.706 Kelvin
Substituting the given values, we get -
1585.79 kPA * 27750.5 Liters = n * 8.315 * 338.706 Kelvin
n = (1585.79*27750.5)/(8.315 * 338.706) = 15625
It is accurate to say that site engineering does not require particular consideration for soils with low percolation rates.
<h3>What are percolation rates?</h3>
- The rate at which water percolates through the soil is a measure of its ability to absorb and treat effluent, or wastewater that has undergone preliminary treatment in a septic tank.
- Minutes per inch are used to measure percolation rate (mpi).
- The process of a liquid gently moving through a filter is called percolation. This is how coffee is typically brewed.
- The Latin verb percolare, which meaning "to strain through," is the source of the word "percolation." When liquid is strained through a filter, such as when making coffee, percolation occurs.
To learn more about percolation rates, refer to:
brainly.com/question/28170860
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Answer:
38 kJ
Explanation:
The solution is obtained using the energy balance:
ΔE=E_in-E_out
U_2-U_1=Q_in+W_in-Q_out
U_2=U_1+Q_in+W_in-Q_out
=38 kJ
Answer:
See explaination
Explanation:
In the below answer "Z" is the output. please kindly check attachment for further details.
When z=1 , the vending machine gives snacks
z=0 , the vending machine doesn't give snacks.
And z becomes 1( high) only when the machine gets 20 cents or more than 20 cents. Since the machine doesn't give change, after giving snacks it will restart from initial state A (where no coins were put).
