Briefly explain all types of engineering fractures?
5. Why steel is the most metallic materials used in engineering?
6. How can you determine the strength of specimen if you don't have tensile test machine in your lab but you have other machines?
In: Mechanical Engineering
In: Mechanical Engineering
Of cobalt based alloys, Titanium based alloys or hydroxyapatite, which would display the highest degree of viscoelastic behavior? Discuss the theories of healing of hard tissue under load & explain how this phenomenon can be exploited in improving the rate of healing.
In: Mechanical Engineering
Spinal implants, knee & hip joints comprise the majority of joint procedures. Describe & classify these joints & discuss the considerations that must be taken into account when designing devices for these applications.
In: Mechanical Engineering
In: Mechanical Engineering
At 300ºC the diffusion coefficient and activation energy for Cu in Si are
D(300ºC) = 7.8 x 10-11 m2/s
Qd = 41.5 kJ/mol
R = 8.314 J/mol -K
What is the diffusion coefficient at 684ºC (in 10-11 m2/s )
In: Mechanical Engineering
Explain the reason for the failure of the Titanic in terms of Materials Science.
In: Mechanical Engineering
Hypothetical metals A and B form an isomorphous binary phase diagram. Assume that you need to increase the strength of an A-B alloy. Can you achieve this with the help of precipitation hardening? Explain.
In: Mechanical Engineering
1) Somewhere along the flow stream in a siphon the pressure is less than atmospheric pressure.
True
False
2)it is reasonable to expect that the top speed of the boat will approximately double if a 9 Hp boat motor is replaced with an 18 Hp boat motor, All else being equal,
True
False
3)In a steady-state flow, it is not possible for fluid parcels of fixed identity to accelerate.
True
False
In: Mechanical Engineering
1.
Given the angle of rotation is small and the materials remain linear elastic, which statement below is incorrect for the torsional behavior of a long straight circular shaft:
| a. |
Straight member remains straight |
|
| b. |
Section-shape remains unchanged |
|
| c. |
End of member may warp |
|
| d. |
Plane section remains plane |
2.
The unit for a shaft’s polar moment of inertia J is:
| a. |
m2 |
|
| b. |
m3 |
|
| c. |
kPa |
|
| d. |
m4 |
3.
Provided that the bending formation of a straight member is small and within elastic range. Which of the following statements is incorrect? (select all that apply)
| a. |
The length of the longitudinal axis remains unchanged |
|
| b. |
Cross-sections remains perpendicular to the longitudinal axis |
|
| c. |
Plane sections remain plane |
|
| d. |
In-plane distortion of cross-sections with respect to the longitudinal axis is negligible |
4.
Which of the following statements is correct for bending of a straight member?
| a. |
Bending stress is inversely proportional to the moment of inertia of the section |
|
| b. |
Bending stress does not depend on the moment of inertia of the section |
|
| c. |
Bending stress is proportional to the moment of inertia of the section |
|
| d. |
Bending stress is proportional to the square of the moment of inertia of the section |
5.
Which of the following statements is true? The flexure formula for a straight member can be applied only when: (select all that apply)
| a. |
the principal axes have their origin at the centroid |
|
| b. |
bending remains in the elastic region |
|
| c. |
bending occurs about axes that represent the principal axes of inertia for the section |
|
| d. |
the principal axes are orientated along an axis of symmetry, if there is one, and perpendicular to it |
In: Mechanical Engineering
design a method for synthesis of titanium based nanoparticles from Catharanthus roseus and mention name of few techniques for its characterization and discuss in detail about the application of designed nanoparticles for controlled drug delievery?
In: Mechanical Engineering
A cylindrical pressure vessel with flat ends of length 6 ft and inner diameter of 35 in. is subjected to an internal gauge pressure of 150 psi. Neglect the end effects and the mass of ends of the pressure vessel in your design. Take the factor of safety as 1.95:
1. Design the radial thickness of the pressure vessel
using steel. For steel, assume that the Young’s modulus is 30 Msi,
Poisson’s ratio is 0.3, specific gravity of steel is 7.8, and the
ultimate normal tensile and compressive strength is 36
ksi.
2. Find the axial elongation of the steel pressure
vessel designed in part (1), assuming plane stress
conditions.
3. Find whether graphite/epoxy would be a better
material to use for minimizing mass if, in addition to resisting
the applied pressure, the axial elongation of the pressure vessel
does not exceed that of the steel pressure vessel. The vessel
operates at room temperature and curing residual stresses are
neglected for simplification. The following are other
specifications of the design:
Only 0°, +45°, –45°, +60°, –60°, and 90° plies can be
used.
The thickness of each lamina is 0.005 in.
Use specific gravities of the laminae from Example
5.6.
Use Tsai–Wu failure criterion for calculating strength
ratios.
In: Mechanical Engineering
Draw diagrams showing the components of a ball mill and movement of charge inside the mill. Label the important features.
In: Mechanical Engineering
In: Mechanical Engineering
An ideal Otto cycle has a compression ratio of 8.5 At the beginning of the compression process, air is at 98 kPa and 27∘C, If the Tmax cannot exceed 2300K and 3e-5 kg of. assuming constant specific heats at ambient temperature, determine (a) the pressure and temperature at the end of each process. (b) the net work output, (c) the thermal efficiency, and (d) the mean effective pressure for the cycle.
In: Mechanical Engineering