Describe grain size refinement, solid solution strengthening, precipiation hardening, and work hardening. Why and when do you use each of these strengthening processes?

Convection heat transfer takes place owing to changes of density within the Fluid.

Discusss convective heat transfer in some detail. Your answer should include relavant sketches, equations and practical applications

1. What are the age hardening alloy systems in Al-based alloys based on classification of major alloyingsystems for Al-based alloys?

2.In alloy system of Al - 4.4%Cu - 0.8%Si - 0.8%Mn - 0.5%Mg which is commonly used for aircraft structures, sketch and explain all transformation stages during age hardening. What is the driving mechanism for each step?

Forced convection

A thin plate is suspended in air at 1 atm. with T? = 15°C. Air flows on both sides of the plate where the bottom side absorbs a uniform radiative heat flux of 1542 W/m2. The plate is oriented parallel to the flow and the length along the flow direction is 60 cm. Consider the plate is negligibly thin and the width of the plate (perpendicular to the flow) is large, so that the problem can be considered as a 2D problem.
1. If the temperature of the plate is not to exceed 80°C at any position, what air velocity would be required? Evaluate the air properties at 310 K. (3 pts)
2. Using the velocity calculated in part 1, find an expression for the heat transfer coefficient (h) and surface temperature (Ts) as a function of distance from the leading edge (x). Graph h and Ts for x = 1 ~ 60 cm.
3. If the length of the plate increases to 1.2 m and other conditions (including the air properties) remain the same as in parts 1 and 2, what is the surface temperature at the end of the plate? Graph h and Ts for x = 0.6 ~ 1.2 m

Why do we need methods in addition to tensile testing?

1. Describe how bauxite is converted to aluminium oxide (Al2O3) via the Bayer process?

2. Describe the Kroll process used to produce metallic titanium. Give the key chemical equation.

3. Give 2 short application examples of the Ellingham diagram in process metallurgy.

4. Name 2 important fields of application of Ti alloys and an alternative processing route that can provide highest purity Ti.

5. What is the main Al ore and where are the world’s largest reserves? Given the fact that these high alumina containing ore bodies might be depleted in 20-30 years, what could be an alternative source?

6. Describe the electro-refining process of copper and give the most important chemical equations.

6. A motor car, of a total mass 1400 kg, running in top gear at 55 km/h, passes on to a rsing gradient of 1 in 20 at that speed. The road and other resistances may be taken as constant at 270 N/t. With condition unchanged, the speed falls uniformly to 40 km/h in a distance of 360 m. An intermediate gear is then engaged for which the speed ratio between the engine and the road wheels is 9:1 and the transmission efficiency is 85 per cent. The engine is then developing a torque of 85 Nm
Determine;
a. The tractive effort before and after the gear change, given that the road wheels are 750 mm diameter, [851 N; 1735 kN]
b. The time between the start of retardation and the recovery of the original speed of 55 km/h and [36 s]
c. The power being developed by the engine when the car is retarding and accelerating through 50 km/h, given that the transmission efficiency in top gear is 94 per cent.         [12.56 kW; 28.35 kW]

4. A wagon of mass 14 tonnes is hauled up an incline of 1 in 20 by a rope which is parallel to the incline and is being wound round a drum of 1 m diameter. The drum, in turn, is driven through a 40 to 1 reduction gear by an electric motor. The frictional resistance to the movement of the wagon is 1.2 kN, and the efficiency of the gear drive is 85 per cent. The bearing friction at the drum and motor shafts may be neglected. The rotating parts of the drum have a mass of 1.25 tonnes with a radius of gyration of 450 mm and the rotating parts on the armature shaft have a mass of 110 kg with a radius of gyration of 125 mm.
At a certain instant the wagon is moving up the slope with a velocity of 1.8 m/s and an acceleration of 0.1 m/s2. Find the torque on the motor shaft and the power being developed. [T= 154 Nm, P=22,24 kW]

A piston with a volume of 0.5 m ^ 3 contains 0.9 kg of water at a pressure of 0.2 MPa. Heat is transferred to the cylinder until the temperature of the steam at constant pressure is 250 ° C. What happens if the change in kinetic and potential energy is neglected?

A piston with a volume of 0.5 m ^ 3 contains 0.9 kg of water at a pressure of 0.2 MPa. Heat is transferred to the cylinder until the temperature of the steam at constant pressure is 250 ° C. What happens if the change in kinetic and potential energy is neglected?

2. A four-wheeled vehicle has a mass of 1500 kg. the tractive resistance is 1100 N. The engine develops 60 kW at maximum speed of 2500 r/min. The gear ratio is 45:1 and the transmission efficiency is 87.5%. Each wheel has an effective diameter of 800 mm, a mass of 25 kg and a radius of gyration of 325 m
The parts rotating engine speed have a mass of 70 kg and a radius of gyration of 100 mm.
Determine:
a. The acceleration in m/s2 under these condition [0.7034 m/s2]
b. The maximum speed of the vehicle, in km/h [83,78 km/h]

(a) Calculate the settling velocity of glass spheres (density = 2467 kg/m3) having diameter as 1.5 mm in water. The slurry contains 65% by weight solid. Use Newton’s law.

(b) Mixture of an ore (density 2000 kg/m3) and gangue (density 7000 kg/m3) is to be separated in a hydraulic elutriator. The mixture has following size distribution, which is valid for ore as well as gangue. Predict the upward velocity of water in elutriator so that entire ore is collected in the overflow. Also ensure that not gangue should be present in overflow. Use fD = 20/Re^0.5 .

A 6 in. schedule 800 steel pipe (OD =6.62 in) will be used to transport 450 F steam from a boiler house to a new process unit. the pipe will be buried at a depth of 3 ft (to be pipe centerline). the soil at the plant site has an average thermal conductivity of 0.4 btu/h.ft F and the minimum expected ground surface temperature is 20 F. Estimate the rate of heat loss per loot of pipe length for the following cases: a. the pipe is not insulated b. the pipe is covered with a 2 in. thick layer of magnesia insulation

The gas phase reaction: 2A+B = 3C , is carried out in an isothermal packed bed reactor. The rate is first order with respect to reactants A and B (second order overall) with the rate constant of 14 [liter2 /mole kg of catalyst sec.]. The feed is 50% A, 25 % B and 25 % inert at temperature of 500 K and P = 18 atm and a total flow rate of 20 mole/sec. The exit pressure is measured to be 6 atm. To produce 12 mole/sec of product C,

a) Write the relevant equations and using POLYMATH, give the profile of pressure and conversion along the catalyst bed till its exit, where the conditions are given above (Pexit = 6atm, Fc=12 mole/sec)

b) Calculate the amount of catalyst needed

c) Calculate the amount of catalyst needed, if the pressure drop in the reactor is ignored.

how can make a doctor really feels the touch sensation while using a surgical robot? i need a plan that aims to create a system of haptic feedback that actually let the doctor feel what the robot is touching
(i just need a logical sequence of ideas without elaboration)