Select the most efficient member for the following LRFD required moments and unsupported lengths. Assume Cb = 1.0.

Evaluate the Design Strength of the following members with the specified unsupported lengths, Lb. Assume Cb = 1.0.

Problem 5. The aquifer source water used by the town of Pandarwin, IL contains 32 mg/L Fe2+ and 97 µg/L arsenic, predominantly in the form of As(III). To meet the new MCL of 10 µg/L the local water utility is considering several strategies. One strategy involves adding hydrogen peroxide (H2O2) to the water. Arsenic removal occurs indirectly as a byproduct of the reaction between Fe2+ and H2O2. When H2O2 reacts with Fe2+, hydroxyl radical intermediates (•OH) are produced which can rapidly oxidize As(III) to As(V). The As(V) can then be removed by coprecipitation with and adsorption onto Fe(OH)3(s) precipitates during sand filtration. The source water is well buffered at pH 8.0 by dissolved carbonate species.

(a) Write the balanced redox reaction between Fe2+ and H2O2. Fe2+ is converted to Fe(OH)3(s) and H2O2 is converted to H2O.

(b) The treatment plant flow rate is 107 L/day. If we assume that the reaction from part (a) goes to completion as written, calculate the mass of H2O2 that will be required each day to consume all the dissolved Fe2+ in the source water entering the plant.

(c) If we assume that each H2O2 molecule generates a single ⋅OH intermediate when it reacts with Fe2+, estimate the fraction of ⋅OH intermediates that will be used to convert As(III) to As(V) in the source water. Assume that each As(III) molecule reacts with only a single ⋅OH intermediate

Assume the speed and density at a freeway location follows a linear relationship.You observe traffic flow rate of 2250 vehicles/hour at 45 mph and 3000 vehicles/hour at 30 mph. What are the jam density, free flow speed (max speed), and capacity of this freeway location? How about the density and speed (i.e., the critical density and the critical speed) at the capacity?

Construction codes and specifications

Discuss the importance of documentation in the construction and civil engineering industry. What
method(s) are used to ensure proper documentation during construction?

Identify all US standards that are associated with pump design and operation and provide an overview of what they govern.

a. Interstitial atoms belong to line defects, yes or no?

b. What is the influence of crystallinity increase on polymer modulus?

c. Why are polymers lighter than metals and ceramics? Two reasons.

d. How can glass fiber be made (name 2 methods/procedures)? 23 24 25 26

e. What are the three main types of materials discussed in EGR218?(Ceramics , polymers & metals?)

f. What are the three limitations of ferrous alloys, generally?

g. Why poly crystals are stronger than single crystals?

h. Can polymers be purely crystalline? Yes/No

i. What are the three functions of screen pack in polymer extruding?

A falling head permeability test was performed on a re-moulded silty clay soil sample 150 mm in diameter and 250 mm in length. The diameter of the standpipe was 12.7 mm. At the start of the test, the height of the water in the standpipe measured 2,236 mm above the constant water level where the soil sample was immersed in. After 7 hours and 45 minutes, the height of the water in the standpipe was measured at 1971 mm. Determine: (i) the coefficient of permeability of the soil (in m/sec), and (ii) the estimated height of the water in the standpipe after a further 12 hours of running this test. (iii) the total time (from the start of the test in days, hours, minutes and seconds) it will take for the water level in the standpipe to reach a height of 600 mm.  

Project management process involves many phases. Construction is one of the phases. Which of the following aspects of the construction phase do you consider as most important as well as most challenging/demanding? Why do you think so?

Third party coordination
Quality Management
Safety management?

Please select only one option and justify your response.

11-1 A particular tilted aerial photograph exposed with a 152-mm-focal length camera has a tilt angle 2°45’ and a swing angle of 140°00’. On this photograph, what are the auxiliary x' and y photocoordinates for points a and b, whose photocoordinates measured with respect to the fiducial axes are xa = 69.27 mm, ya = -41.80 mm, xb = -54.72 mm, and yb = 106.38 mm?

11-3 Calculate photographic scale for image points a and b of Prob. 11-1 if flying height above datum was 7.200 ft and if elevations of points A and B were 865 ft and 1,232 ft above datum, respectively.

11-8 Compute the tilt displacement of the two points in Prob. 11-1

A Seven-sided closed field traverse has the following angles and distances in meters which were measured using a Total station:

AB = 51.7660;

BC = 76.9470;

CD = 37.0700;

The adjusted angles are as follows:

A = 128˚27’02”;

B = 101˚41’49”;

C = 102˚22’05”;

D = 143˚12’43”;

E = 161˚08’23”;

F = 131˚57’22”;

G = 131˚10’35”;

DE = 29.2019;

EF = 28.7758;

FG = 36.7056;

GA = 41.9555;

azimuth AB =251˚00’00''

question

1. Compute the coordinates of the traverse stations using coordinates of station A as 1,000.000 N, 1,000.000 E.
2. Compute the area enclosed by the traverse using the co-ordinate method.
3. It was decided to divide the traverse into two parts AGFED and DCBA, find the area of each part and the length and direction of AD.

A 16-ft long pin-pin column has to support a dead load of 100 kips and a live load of 280 kips. Using column selection tables from the Steel Manual select columns for the given shapes. All selections should be structurally safe and least weight.

50-ksi W-section (W10, 12, 14 only)

35-ksi pipe (standard, x-strong, xx-strong)

46-ksi rectangular HSS

46-ksi square HSS

42-ksi round HSS

square footing 4×4 m carrying a load of 400 KN and the moment of 200 KN.m compute the maximum and minimum bearing pressure

Responses may be 2-3 short sentences, diagrams, and/or equations as described in the question.

What is a principal plane and why is it important to determine its orientation?