PRACTICE MULTIPLE CHOICE QUESTIONS ON LECTURE 3, 4 AND 5
Diffusion is always occurring in materials, even when the material is absolutely pure. However a net
flux is produced only if
a) if the temperature is more than 0.4 times the absolute melting temper

TTE 5835 Pavement design and analysis
TTE 5835: Pavement Design and Analysis
Fall 2014
Catalog Description:
Function and material requirements of different elements of flexible and rigid
pavement systems; characterization of soils, materials, traffic load

Multinomial Logistic Regression- Nominal Outcomes
Example 1. Health Insurance Plans
Employees are asked to choose one of three plans (say 0, 1, 2).
The outcome variable Y (employees choice) is nominal with three
categories, distribution of Y is tri-nomi

Logistic Regression: Sampling Methods and Analysis
Simple Random Sample
An observation on a binary outcome variable y and p
independent variables x1, x2, xp are obtained from each of n
subjects or units selected completely at random from a
population of

TTE 5835
Fall 2014
HW #2
Due: September 4, 2014
1. (10 points) State the definitions of following terminology.
(a) Elastic behavior
(b) Youngs modulus (E) and Shear modulus (G)
(c) Poissons ratio
(d) Linear-nonelastic behavior (provide a diagram)
(e) Visc

Multiple Logistic Regression Model
Binary outcome, several quantitative/qualitative
independent variables x1, x2, xk
Logit(x)=ln(x)/(1-(x)= g(x1, x2, xk) = g(x), say.
exp(g(x)
(x)
=
1+ exp(g(x)
Two problems that need to be addressed are
Determine the

Analysis of binary outcome variable Statistical Model
Recall ICU Data Example
Looked at the mortality (STA) rate ignoring all factors that affect STA;
One sample proportion problem (estimation and test)
Looked at the association between admission (TYP

Exam 1
1. Difference between sensitivity and specificity
2. Difference between odds ratio and risk ratio
Odds ratio is how much likely or less likely it is for the odds of event which develops in group
E relative to group U.
Risk ratio is an individual in

Multiple Logistic Regression Model
Mathematical representation of the relationship between a
binary outcome variable and a set of p covariates
Multiple Linear Logistic Regression
Suppose we have a sample of n independent observations (y i, x1i, ,
xpi),

UNVERSITY OF BOTSWANA
DEPARTMENT OF CIVIL ENGINEERING
COURSE: CCB211 (ENGINEERING MATERIALS)
TUTORIAL SHEET NO.1
DATE: August 2016
1. Raise the THREE queries that must guide the process of selecting a material for Fitness
for Purpose.
2. In determining th

TUTORIAL 5 SEPTEMBER 2016 (DIFFUSION)
1. The diffusion coefficient for Cr in Cr2O3 is 610-19m2.s-1 at 727C and is 110-13m2.s-1 at 1400C.
Calculate:(a) the activation energy Q
(b) the constant D0
2. A 0.2 mm thick wafer of Si is treated so that a uniform c

TUTORIAL 6 (2016) MECHANICAL PROPERTIES OF MATERIALS
1. A 6 m long spring steel wire, 1.5 mm in diameter, is loaded with 150 kg. The length of the wire
increases to 6.12 m. Calculate the following:(a) Tensile stress, tensile
(b) Tensile strain, tensile
(c

TUTORIAL SHEET NO. 7 (OCTOBER 2016)
PRINCIPLES OF SOLIDIFICATION
1. Solid nickel (Ni) forms by homogeneous nucleation. What will be:(a) The size of the critical radius?
(b) The number of atoms in the critical nucleus?
You are given the lattice parameter o

TUTORIAL 4 of SEPTEMBER 2016
1. Calculate the interplanar spacing and length of the Burgers vector for slip on the expected slip
systems in FCC aluminium (Al). Assuming that the slip is a (110) plane and a [1 1 1] direction,
re-calculate the same paramete

UNIVERSITY OF BOTSWANA
DEPARTMENT OF CIVIL ENGINEERING
COURSE: CCB211 (ENGINEERING MATERIALS)
TUTORIAL SHEET NO.2
DATE: August, 2016
1. Derive the expressions relating the atomic radius to the lattice parameter in:(a) Simple cubic (SC) structure
(b) Body-

TUTORIAL 3 September 2016.
1. A steel part of area 0.24m2 is plated with a 0.04 mm thick layer of nickel (Ni).
(a) How many atoms of Ni are in the coating?
(b) How many moles of Ni are in the coating?
You are given the density & atomic mass of Ni: Ni= 8.9

Model Assessment: Goodness-Of-Fit and Diagnostic Measures
A model is considered a good fit to the data if
summary measures of the distance between observed y and predicted y are
small
the contribution of each pair (observed y, predicted y) to summary
m

Designation: E8/E8M 15a
American Association State
Highway and Transportation Officials Standard
AASHTO No.: T68
An American National Standard
Standard Test Methods for
Tension Testing of Metallic Materials1
This standard is issued under the fixed designa