In: Mechanical Engineering
In: Mechanical Engineering
What is the answer to this question?
Imagine if an artificial cartilage is fully made of chondrocytes which has a compression modulus 0.41 KPa and apparent viscosity of 3.0 KPa.s.
a) If such a artificial cartilage is under a sudden load stress
of 0.1 KPa, use a simple Kelvin model, can you give an estimate of
the time period needed to equilibrium from the given mechanical
properties?
b) What is the final equilibrium strain?
c) Plot out the creep function (strain/load stress) of this
cartilage under a sudden load stress of 0.1 MPa at time t=0.
You can modify the sample Matlab skeleton code below.
syms sig0 eps emod mvis
dsolve('Deps + (emod/mvis)*eps = sig0/mvis') emod=0.1;
mvis=1.0;
sig0=1.0;
C5=1.0;
t=0:1:100;
epsresult=(sig0 - C5*exp(-(emod*t)/mvis))/emod
plot(epsresult,t);
d) Comment on why a good artificial cartilage can not be made with only chondrocytes and what is missing.
In: Mechanical Engineering
Problem 2: Plot the LST (y?axis) corresponding to 10:00 AM versus months (x?axis) (consider the 21st day of each month as the representative of each month) for Panama City Bay, Florida.
In: Mechanical Engineering
What is the best way to reduce the average grain size in a metal speciman.
In: Mechanical Engineering
A thick steel slab (ρ= 7800 kg/m3, c= 480 J/kg·K, k=
50 W/m·K) is initially at 300°C and is cooled by water jets
impinging on one of its surfaces. The temperature of the water is
25°C, and the jets maintain an extremely large, approximately
uniform convection coefficient at the surface. Assuming that the
surface is maintained at the temperature of the water throughout
the cooling, how long will it take for the temperature to reach
50°C at a distance of 28 mm from the surface?
In: Mechanical Engineering
1- The interdependence between materials and their __________
must also be recognized.
a.
environment
b. processing
c. structure d. properties
2-The design process primarily consists of design, prototype,
and __________ stages.
a. production
b. selection
c. quality d. structure
3- Approaches to material selection goes through a sequence of
activities of design, material selection, process selection,
manufacture, evaluation, and _________.
a. production
b. marketing
c. feedback d. none of
the above
4- List three geometric considerations to consider for the needs
of the product.
5- List three mechanical properties to consider for the needs of
the product.
6- List three physical properties to consider for the needs of
the product.
Chapter 11: Fundamentals of Casting
1- A primary objective of materials processing is the production
of a desired shape in the __________ quantity.
a. maximum b.
minimum c.
multiple d. none of the above
2- The six basic steps in most casting processes include using a
mold cavity, melting process, pouring technique, solidification
process, mold removal. List the sixth step.
Sixth step is:
3- One of the first features that must be considered by a
designer of castings is the location and ___________ of the parting
plane.
a.
orientation
b. dimensional
accuracy c.
design d. quality
4- __________ is the term used to describe he taper on a pattern or casting that permits it be withdrawn from the mold.
Riser b.
Gate c.
Draft d. none of the above
In: Mechanical Engineering
1- The interdependence between materials and their __________
must also be recognized.
a.
environment
b. processing
c. structure d. properties
2-The design process primarily consists of design, prototype,
and __________ stages.
a. production
b. selection
c. quality d. structure
3- Approaches to material selection goes through a sequence of
activities of design, material selection, process selection,
manufacture, evaluation, and _________.
a. production
b. marketing
c. feedback d. none of
the above
4- List three geometric considerations to consider for the needs
of the product.
5- List three mechanical properties to consider for the needs of
the product.
6- List three physical properties to consider for the needs of
the product.
Chapter 11: Fundamentals of Casting
1- A primary objective of materials processing is the production
of a desired shape in the __________ quantity.
a. maximum b.
minimum c.
multiple d. none of the above
2- The six basic steps in most casting processes include using a
mold cavity, melting process, pouring technique, solidification
process, mold removal. List the sixth step.
Sixth step is:
3- One of the first features that must be considered by a
designer of castings is the location and ___________ of the parting
plane.
a.
orientation
b. dimensional
accuracy c.
design d. quality
4- __________ is the term used to describe he taper on a pattern or casting that permits it be withdrawn from the mold.
Riser b.
Gate c.
Draft d. none of the above
In: Mechanical Engineering
Complete the following program so that C = A*B where A and B are the matrices defined below.
N=4;
M=3;
A=rand(M,N);
B=rand(N,M);
C = ?
for m = 1: M
for n = 1 : ?
for p = 1 : ?
C (m,n) = ?
end
end
end
You may upload a script
In: Mechanical Engineering
What are some of the common decision-making errors that teams and groups encounter?
In: Mechanical Engineering
An insulated pump receives liquid engine oil (density ρ = 55 lbm/ft3 , specific heat c = 0.442 Btu/lbm-R) at 75 oF and 15 psia, and exhausts the oil at 3000 psia and 140 oF. The mass flow rate of the oil is 1.2 lbm/s. Determine the power required by the pump.
In: Mechanical Engineering
step by step solution on how to create Index Slide in solidworks
In: Mechanical Engineering
The air in a room has a pressure of 1 atm, a dry-bulb temperature of 24°C, and a wetbulb temperature of 17°C. Using the psychrometric chart, determine
(a) The specific humidity,
(b) The enthalpy, in kJ/kg dry air,
(c) The relative humidity,
(d) The dew-point temperature,
and (e) The specific volume of the air, in m3/kg dry air.
In: Mechanical Engineering
Air enters a steady-flow turbine. The conditions of the air entering and leaving the
turbine are as follows: inlet, 300 kPa and 52°C; exit, 100 kPa and 12°C. The mass
flow rate is 10 kg/s. Heat transfer from the turbine to the surroundings and the
kinetic and potential energy effects are negligible. Calculate the power developed
by the turbine. Determine whether the process in the turbine is reversible. If not,
determine the isentropic efficiency of the turbine.
In: Mechanical Engineering
In large steam power plants, the feedwater is frequently heated in closed feedwater heaters (basically heat exchangers) by steam extracted from the turbine at some stage. Steam enters the feedwater heater at 1.5 MPa and 250℃ and leaves as saturated liquid at the same pressure. Feed water enters the heater at 2.5 MPa and 60℃ and leaves at 10℃ below the exit temperature of the steam. Neglecting any heat losses from the outer surfaces of the heater, determine (a) the ratio of the mass flow rates of the extracted steam and the feedwater heater and (b) the total entropy change for this process per unit mass of the feedwater.
In: Mechanical Engineering