Please briefly answer all the questions below, and writing those clearer and tidier (It is best to use typing)

This is a problem related to the transmission electron microscopy (TEM)

1. What is the difference between the field-emission and thermionic source TEMs?
2. What is the purpose of the Wehnelt in a thermionic source? Why don’t we need one in a field emission gun(FEG)?
3. Define ‘underfocused’ and ‘overfocused’ in the TEM?
4. What causes spherical aberration and chromatic aberration?

6b2. Discuss two laser characteristics that are important for evaluating use in materials processing (laser cleaning, cutting, or welding).

For the following questions please use more detail than the band theory explanation.

1a) What atomic energy levels combine to form the valence band?? Please specify the specific energy levels; a diagram will help!

1b) What atomic energy level combine to form the conduction band?? Please specify the specific energy levels and a diagram!!

1c) If there is a relatively low concentration of an ionic impurity in an insulator how does its electronic structure appear in the band structure of the insulator (please include a diagram in your answer).

Answer each of the following questions in one paragraph. If you want/need, you can supplement your written explanation with diagrams or equations.

2. Using the Michelson-Morley experiment as an example, explain why classical mechanics was unable to explain natural phenomena.

1. Describe the early history of the Sun. What did it start as? What lead to it becoming a smallish main sequence star? 2. Describe the future of the Sun. Roughly how long will it take for the Sun to leave the main sequence? What will happen when it leaves the main sequence? Will the Sun go supernova? 3. The remnants of stars 25 to 40 times more massive than the Sun may have such a strong _______ pull that their escape speeds exceed the speed of _______ , resulting in a _______. 4. The ________________ of a star (determined after observing the star 6 months apart) can be used to determine the distance to a star, but it is only effective for the closest stars to us. 5. what process is energy produced in the core of the Sun (and other stars as well)? Be as specific as possible.

5b. Describe the basic physics aspects of photoemission and its application in a vacuum photodiode.

Two equal mass object experience a totally inelastic elastic collision. Mass 1 has an initial velocity of 10 m/s in the negative y-direction. Mass 2 has an initial velocity of 10 m/s in the positive x-direction. The collision occurs at the origin. What is the magnitude and direction of the velocity of the combined mass? What is the kinetic energy conserved in the collision? If not what fraction of kinetic energy was lost?

Launch a book from a cannon which is inclined at 45 degree to the horizontal and facing east. Write pertinent formulas and calculations that explains the motion of the book through space. Consider the effects due to: gravity near the surface of the Earth, air friction, the rotation of Earth and pseudo forces, the shape of the book and its rotation, universal gravitation, special relativity, and chaos theory. Consider a large range of initial velocities: from so small that the book just barely leaves the cannon to so large to consider special relativity.

a) A tumour located at a depth of 10 cm is treated using a non-isocentic technique with a Co-60 machine, to a dose of 1.8 Gy, with a single 5 cm x 5 cm beam. Compute the maximum dose received anywhere in the patient's anatomy. Refer to the attached table for PDD data. (5 pts) b) At what depth does the maximum dose occur? Explain. (5 pts) b) Compute the dose at a depth of 5 cm along the beam axis. (5 pts) c) Would this be a good treatment strategy? Explain. (5 pts)

a) A tumour located at a depth of 10 cm is treated using a non-isocentic technique with a Co-60 machine, to a dose of 1.8 Gy, with a single 5 cm x 5 cm beam. Compute the maximum dose received anywhere in the patient's anatomy. Refer to the attached table for PDD data. (5 pts)

b) At what depth does the maximum dose occur? Explain. (5 pts)

c) Compute the dose at a depth of 5 cm along the beam axis. (5 pts)

d) Would this be a good treatment strategy? Explain.

Percent Depth dose (in %) table for Co-60 beam for different depths and field sizes.

A tumour located at a depth of 10cm is treated using a non-isocentric technique with a Co-60 machine, to a dose of 1.8 Gy, with a single 5cmx5cm beam.

a) Compute the maximum dose received anywhere in the patients anatomy. Refer to the attached table for PDD data.

B) at what depth does the maximum dose occur? Explain

c) computer the dose at a depth of 5 cm along the beam axis.

d)would this be a good treatment strategy

NEED ANSWERED ASAP

A tumour located at a depth of 10 cm is treated using a non-isocentic technique with a Co-60 machine, to a dose of 1.8 Gy, with a single 5 cm x 5 cm beam. Compute the maximum dose received anywhere in the patient's anatomy. Refer to the attached table for PDD data.

a) At what depth does the maximum dose occur?

b) Compute the dose at a depth of 5 cm along the beam axis

a tumour located at a depth of 10 cm is treated using a non-isocentic technique with a Co-60 machine, to a dose of 1.8 Gy, with a single 5cm x 5cm beam. Compute the maximum dose received anywhere in the patients anatomy.

b)At what depth does the maximum occur? Explain

c) compute the dose at a depth of 5 cm along the beam axis

d) Would this be a good strategy? Explain

percent dose (in %) table for Co-60 beam for different depths and field sizes

Two identical double-pipe heat exchangers are constructed of a 2-in standard schedule 40 pipe placed inside a 3-in standard pipe. The length of the exchangers is 10 ft; 40 gal/min of water initially at 80◦F is to be heated by passing through the inner
pipes of the exchangers in a series arrangement, and 30 gal/min of water at 120◦F and 30 gal/min of water at 200◦F are available to accomplish the heating. The two heating streams may be mixed in any way desired before and after they enter the heat exchangers. Determine the flow arrangement for optimum performance (maximum heat transfer) and the total heat transfer under these conditions. Use both NTU and LMTD methods.

1) Sinusoidal Motion Properties in Spring Mass System- A 200g mass hangs from vibrating spring at lowest point of 3cm above table and at it's highest point at 12cm above table. It's oscillation period is 4seconds. Determine the following:

a. The spring constant in terms of T (period)

b. The maximum velocity magnitude and maximum acceleration magnitude

c. The velocity magnitude at 10cm above table

d. The vertical position, velocity magnitude and acceleration magnitude at 5 seconds