countershaft in Prob. 3–72, p. 152, is part of a speed reducing compound gear train using
20° spur gears. A gear on the input shaft drives gear A. Gear B drives a gear on the output
shaft. The input shaft runs at 2400 rev/min. Each gear reduces the speed (and thus increases
the torque) by a 2 to 1 ratio. All gears are to be of the same material. Since gear B is the
smallest gear, transmitting the largest load, it will likely be critical, so a preliminary analysis
is to be performed on it. Use a diametral pitch of 2 teeth/in, a face-width of 4 times the circu-
lar pitch, a Grade 2 steel through-hardened to a Brinell hardness of 300, and a desired life of
15 kh with a 95 percent reliability.

1) if b is meshing with another gear with a diameter d=16 in what would be the required teeth on Fb?

2)Determine factors of safety for pitting

GD&T

Explain followings:

1. Dimention placement in multiview drawings

2. General arrangement of dimensions in multuview drawings

3. Dimension system

What do you think are the advantages and disadvantages of isothermal constant volume high extension cycle? And how efficient do you think it can be?

A thick spherical pressure vessel of inner radius 150 mm is subjected to maximum an internal pressure of 80 MPa. Calculate its wall thickness based upon the (a) principal stress theory, and (b) total strain energy theory. Poisson's ratio = 0-30, yield strength 300 MPa.

please answer only if you know correctly.

Diffusion in material

You are hardening a very thick tool plate made of BCC Fe by increasing the carbon concentration in its surface layer by heating the tool in the presence of a C-rich gas (e.g. methane) which maintains a constant C concentration at the surface. A heat treatment at 600 °C for 100 minutes results in a C concentration of 0.75 wt% at a position 0.5 mm below the surface. How long would it take to obtain the same result (i.e. the same C concentration at the same depth) if the heat treatment were conducted at 900 °C. Schematically draw the C concentration profile (i.e. the C composition as a function of the distance from the surface) in the tool plate. At either of the temperatures, does the diffusion rate (measured by the diffusion flux) go up or down with increasing distance from the surface and why?

D₀ = 2 x 10^-6 m²/s and Q_d = 84 kJ/mol

What is the difference between a vane compressor and a radial compressor?

Geometric Dimensionig and Tolerancing

1. Professions (desiner, manufacturing engineer, machinist, machine programmer, inspector, tool designer) and trades, that how affected by dimentions?

2. How to reduces cost? by design through teamwork (inspector, machinist, engineer)

Kate deposits P5,000 to her bank account every year when she was in high school for four years to prepare for her college degree. She took an engineering course and since then, she stopped depositing to her bank account. Right after graduation (she graduated on time), she got a job that pays P250,000 a year. If she continues to deposit to the same bank account P50,000 every year for 10 years, calculate the future worth after 30 years if the deposits are made at the end of each year and the bank pays 2% interest per year

Search the Internet and locate a job posting from a Part 121 or 135 carrier. After locating your position, read and review the required maintenance organization management positions in AC 120-16F, Chapter 4. How does the position and job description that you identified align with one of the required positions in the advisory circular? How does it differ?

(a) While shopping at a thrift store, you purchase a cheap water-heater. The heater has a total surface area of 3 m3 which you decide to insulate using a special kind of insulation material with conductivity of 0.08 W/m K. For normal operation, you want to maintain the inside surface of the insulation at 75C while the outside is at 20C. Additionally, you want to limit heat transfer loss to 200 W. Given your requirements, how thick does the insulation need to be?

(b) The heaters on a Space X spacecraft suddenly fail. Given your expertise insulating thrift store waterheaters, you are called in to help. You discover that without the heaters, the spacecraft is losing heat via radiation at a rate of 100 kJ/h. The onboard systems generate heat at 75 kJ/h. The air within the spacecraft is at a temperature of 25C and a pressure of 100 kPa, and occupies a 10 m3 volume. Your job is to determine how long it will take before the air temperature within the spacecraft reaches - 20C.

Compare and differentiate between metal matrix composite and metal alloys in term of structure, properties and applications.(6marks)

Explain the general concept behind rotary aircraft structure and construction methods.
And describe the airworthiness requirements applicable to the design and construction of a typical rotary aircraft fuselage and system such as phlone, fule storage and symmetry

Calculate the critical size for a cube shaped nucleus which forms by homogeneous nucleation

Technology management is concerned with development, planning, implementation, and assessment of technological capabilities within an organization or entity. A simple way to think of it is management of the use of technology for human advantage.  

What, in your opinion, are the most important aspects of technology management and why? Write a 200 word minimum summary of your thoughts with rationale for your assertions.

Use and include a minimum of two external sources for your assessment.

Write in yr own words introduction and conclusion about rotary turbine aeroplane structure and system of helicopter and aircraft???