A packed bed of uniform spherical particles of diameter, d= 2.5 mm, density ρs= 4000 kg/m3 , and voidage e= 0.45 is fluidised by means of a liquid of viscosity μ= 1 mN s/m2 and density ρ= 900 kg/m3 . (a) Starting from Carman’s and Ergun’s equations reported in the attached equations sheet, derive the corresponding expressions for the minimum fluidising velocity, umf, for both equations and explain their meaning.

A falling-head permeameter containing a silty clay loam soil sample has a sample diameter of 10 cm, a falling-head tube of diameter 2 cm, and a sample length of 4 cm. If the initial head is 15 cm. It falls 4 cm over a period of 6 hours. (a) Find the hydraulic conductivity of the soil sample in m/s and ft/d.

(b) What would be the hydraulic head after 12 hours?

(c) How long would it take for the hydraulic head to drop to 95% of the initial value?

An ideal gas is expanded from 5 bars to 1 bar through isentropic(reversible and adiabatic) operation of a turbine. For ambient conditions at 25°C and 1 bar, calculate the exergy of the turbine when the gas inlet temperature to the turbine is:

I) above ambient conditions at 250°C (8marks)

ii) below ambient condition at -50°C (8marks)

iii) comment on your answer to I and ii above (4marks)

(Cp=1.0KJ/Kg.K , n=1.4)

Carbon dioxide dissolved in soda can escape from the PET bottle slowly by means of diffusion. How long does it take for the soda to lose 10% of its original concentration? The following information might be useful: The inside surface of the bottle can be assumed to be saturated with carbon dioxide. The outside surface concentration can be neglected. It can be assumed that diffusion only takes place through the walls of the cylinder and not through the top or bottom. The bottle can be considered as a cylinder.

Diffusivity of CO2 in PET = 2×10-13 m2 /s;

Inner diameter of the bottle = 0.08 m;

Height of the bottle = 0.2 m;

Solubility limit of CO2 in PET = 10 kg CO2 per m3 of PET;

PET thickness = 0.5 mm;

Initial concentration of CO2 in cola = 7 g/L

State whether the following statements are CORRECT or FALSE. If statement is FALSE, correct it

. 1- Smelting is a process that is used to extract Aluminium from ore

. 2- To measure the mechanical property of a material, in non-destructive testing, you need to destroy the specimen.

mixture of 10 kmol of 70 mol% benzene in toluene is distilled at atmospheric pressure using differential distillation with a constant boil up the rate of 10 mol/min. When 50% (by mole) has been vaporized, report the residue composition, the average vapor composition, the temperature of the still, and how long the process takes using :

1. K-constant=1.48

2.alpha constant=2.41

I am currently pursuing my chemical engineering degree. I want to know, if i want work in chemical industry in future, what are the most important Subject (specific topic) / concept which are important from industry perspective (list them). Also list some of most important book that every chemical engineer should have. Thankyou!!

Explain the applications of the solid/vapor equilibrium.

Air at a temperature of 20 0C and 750 mm Hg has a relative humidity of 80%. Calculate,

(i)The molal humidity of the air

(ii)The molal humidity of this air if its temperature is reduced to 10 °C and pressure increased to 2000 mm Hg condensing out some of the water

(iii)Weight of water condensed from 1000 litre of the original wet air

Vapour pressure of water at 20 °C = 17.5 mm Hg

Vapour pressure of water at 10 °C = 9.2 mm Hg

A mixture of 85% n-heptane, remaining cyclohexane gas at 1 bar and 308 K is compressed to a final state at 1443.47 K and 64.475 bar. Estimate the enthalpy and entropy changes for the process using residual properties and by the Lee/Kessler correlations. In its initial state, the system may be assumed an ideal gas.

A mixture of 85% n-heptane, remaining methanol gas at 1 bar and 308 K is compressed to a final state at 1220.04 K and 113.575 bar. Estimate the enthalpy and entropy changes for the process using residual properties and by the Lee/Kessler correlations. In its initial state, the system may be assumed an ideal gas.

What do you think of the materials used in Smartphones?

You must write one paragraph, with a topic sentence and supporting ideas, and citations and an APA reference list.

Question 1. Estimating the time of a victim’s death during homicide investigations is a complex problem that cannot be solved by analysising simple equations or functions of one variable. However, many mathematical texts examine time of death estimation based around analysis of Newton’s Law of Cooling. Such analysis is based on implicit simplifying assumptions that: the only dependent variable of interest in determining the time of death is the victim’s body temperature, T(t); the victim’s baseline body temperature when alive, T0, is known; and the air temperature of the victim’s surroundings, Ts, is constant. Here we will examine such a problem.
(a) Assume that immediately following death, a victim’s body begins to cool from a standard healthy body temperature of 37◦ Celsius. Further, assume that experimental work has determined that the rate constant in Newton’s Law of Cooling for a human body is approximately k = 0.1947 when time t is measured in hours. Determine a function derived from Newton’s Law of Cooling, T(t), that models the temperature of a victim’s body t hours after death, assuming that the temperature of the body’s surroundings is a constant 15.5◦ Celsius.

(b) If the temperature of the victim’s body is now 22.2◦, how long ago was their time of death?

(c) If the victim’s body temperature at death had instead been 36.3◦ Celsius (within the range of normal body temperatures for a healthy adult), what time of death would be estimated via a Newton’s Law of Cooling model? By what duration does this estimate differ to the time that you determined in part (b)?

(d) In reality, how might the modelling assumptions made to address this problem be violated?