What are the factors affect coagulation and flocculation process?

A doubly drained specimen, 2.54 cm in height, is consolidated in the lab under an applied stress. The time for 50% overall (or average) consolidation is 12 min.

(a) Compute the cv value for the lab specimen.

(b) How long will it take for the specimen to consolidate to an average consolidation of 50%?

(c) If the final consolidation settlement of the specimen is expected to be 0.43 cm, how long will it take for 0.18 cm of settlement to occur?

(d) After 14 minutes, what percent consolidation has occurred at the middle of the specimen?

1. Determine the 25-year flow for a 200 square mile watershed in Region 10 of Arizona, which has annual precipitation of 15 inches per year. Comment on its accuracy, that is what are the upper and lower error estimates in terms of cubic feet per second.

2. Determine the 5-year flow for a 25 square mile watershed in Region 14 of Arizona at an elevation of 5000 feet. Comment on its accuracy, that is what are the upper and lower error estimates in terms of cubic feet per second.

3. Determine the 100-year flow of a 70 square mile watershed in Region 12 of Arizona at an elevation of 3500 feet. Comment on its accuracy, that is what are the upper and lower error estimates in terms of cubic feet per second.

1. Describe and sketch a weld cross section including the weld metal, heat affected zone, and base metal on cold worked material. In the heat affected zone, make sure to label what is happening as the distance increases from the weld.

Determine the reactions at the support of the beam. Shear force and bending moment for the beam are described by V(x)= c0 + c1x + c2x2 and M(x)= k0 + k1x + k2x2 + k3x3, respectively. Calculate the coefficients for the shear force and bending moment equations. Use L = 5.8 m, q = 2.7 N/m, and w = 8.6 N/m for your calculation.

Also, determine

Vertical reaction force at A in N (upwards force is positive, round your result to 1 decimal place)

Reaction moment at A in Nm (clockwise moment is positive, round your result to 1 decimal place)

Location of the maximum shear force in the beam in m (round your result to 1 decimal place)

Maximum shear force in the beam in N (round your result to 1 decimal place)

Discuss the feasibility, difficulties, and merits of building an offshore wind farm in Hong Kong.

Identify five product, structure or system designs you think can be improved. For your initial post, pick one of the five and write a preliminary problem statement for the engineering design process.

1) Describe how you can use measurements of stream height (stage) to estimate discharge and what pieces you need to do so. (I’m looking for you to describe both the curve and one method for making discharge measurements)

2) If a flood occurs and erodes the channel where we are measuring stage, can we still use the same relationship between stage and discharge? Why or why not?

In the year 2015, leaders from 193 countries of the world gathered and moderated by the United Nation and finally summarized that there are 17 goals for the world to be achieved in 2030 named as UNDP Sustainable Development Goals (SDG) towards 2030.

1. Explains 5 (five) of the goals with the examples that important to be in line with engineering profession which you can contribute in your career after graduation.

THIS IS THE LINK FOR 17 GOAL.

https://www.undp.org/content/dam/undp/library/corporate/brochure/SDGs_Booklet_Web_En.pdf

Pick two of the five assumptions that are required to apply the unit hydrograph to a watershed. For each assumption, state what it is, describe it, and give an example of how that assumption might be violated in the real world.

A) what is the difference between BOD vs COD and sBOD vs sCOD ?

B) Explain the application of using TBOD, sBOD, sCOD and TCOD.

C) which measurement should be used to evaluate or make sure that the process is working properly: i) Primary treatment ii) Secondary treatment with clarifier iii) secondary treatment with membrance

A Sample of coarse grained soil tested in the laboratory. The gradation analysis results are as shown
in the table below.
Sieve Size
(mm)
Mass retained on
each sieve (g)
4.75 0
2.00 40
0.850 60
0.425 89
0.250 140
0.180 122
0.150 210
0.075 56
Pan 12
Classify the soil according to Unified Soil Classification System (USCS)

The City of Columbus recently issued an NPDES permit to a beer brewery discharging wastewater at a flowrate of 0.15 m³/sec into Buckeye Creek (flowrate = 0.25 m³/sec), such that BOD₅ of immediately after discharge must not exceed 2.5 mg/L. Upstream of the discharge, BOD₅ in Buckeye Creek was measured at 1.5 mg/L. BOD decay rate constants were measured separately for the upstream creek (k = 2 d^-1), the wastewater effluent (k = 0.2 d^-1), and the downstream creek after mixing (k = 0.5 d^-1).

1. What would be the ultimate BOD of Buckeye Creek immediately upstream and downstream of the wastewater discharge, assuming the brewery meets the permitted BOD₅?
2. What would be the wastewater’s maximum ultimate BOD to meet the NPDES permit limits?
3. If this discharge caused an initial dissolved oxygen deficit in the stream of 2 mg/L, what would be the oxygen deficit at the critical point?

finite element problem

Tapered bar subjected to variable axial distributed load A Titanium tapered bar of 25 in. length has a variable cross-sectional area that decreases linearly from 20 in2 to 10 in2 . It is fixed at one end and subjected to an axial concentrated force F = 100 kip at the free end, as shown in the following figure. It’s also subjected to a linearly axial distributed load of variable intensity ?(?) = 0.1 (1 − ? ? ) kip/in. The problem is considered as one dimensional, and the aim of this project is to find, using Finite Element Method, the displacement ?(?) at any position on the x-axis.

The differential equation governing this elastic bars problem is given by: − ? ?? (??(?) ?? ??) − ?(?) = 0 ; 0 < ? < ? Where ? is the Titanium’s Young Modulus of 16. 106 ???; ?(?) is the variable cross-sectional area; and ?(?) is the intensity of the axial distributed load.

Part A: a) Give the expression of the differential equation governing this problem as a function of ?;

b) Give the approximate functions for a quadtratic element;

c) Give the elementary stifness matrix for a quadtratic element;

d) Give the elementary load vector for a quadtratic element;

Part B: We’ll calculate the displacement using a Finite Element Model of one quadratic element.

a) Give the elementary stiffness matrix of the element representing the whole bar

b) Give the elementary load vector of the element representing the whole bar;

c) Give the global matrix form of the Finite Element Model;

d) Give the boundary conditions on the nodal variables (primary as well as secondary variables)

e) Give the condensed equations of the Finite Element Model;

f) Calculate the displacements at ? = ? and ? = ? /2

g) Using the approximation functions, calculate the displacements at ? = ?/ 4 and ? = 3?/ 4

Part C: We’ll calculate the displacement using a Finite Element Model of two quadratic elements.

a) Give the elementary stiffness matrix of each element;

b) Give the elementary load vector of each element;

c) Give the global Matrix Form of the Finite Element Model;

d) Give the boundary conditions on the nodal variables (primary as well as secondary variables);

e) Give the condensed equations of the Finite Element Model;

f) Calculate the displacement at ? = ? /4 ; ? = ? /2 ; ? = 3? /4 and ? = ?..

Design an aeration tank for activated sludge wastewater treatment designed to meet an effluent standard of 10 mg/L BOD₅. The flow from the primary effluent is 10 m³/min with a primary effluent BOD₅ of 250 mg/L. The design calls for the suspended solids to equal 3500 mg/L for an SRT of 5 days. The decay rate constant is 0.03 day^-1 and the yield is 0.75 mg/mg. Determine:

1. the tank volume required to meet these specifications,
2. the resulting mass of sludge wasted each day (kg/day), and
3. the F/M ratio.