Suppose water is leaking from a tank through a circular hole of area

A_h

at its bottom. When water leaks through a hole, friction and contraction of the stream near the hole reduce the volume of water leaving the tank per second to cA_h

, where

c (0 < c < 1)

is an empirical constant.

A tank in the form of a right-circular cone standing on end, vertex down, is leaking water through a circular hole in its bottom. (Assume the removed apex of the cone is of negligible height and volume.)

(a)

Suppose the tank is 20 feet high and has radius 8 feet and the circular hole has radius 2 inches. The differential equation governing the height h in feet of water leaking from a tank after t seconds is

= −

. In this model, friction and contraction of the water at the hole are taken into account with

c = 0.6,

and g is taken to be

32 ft/s².

See the figure below.A right-circular conical tank containing water is shown.

• The cone opens upward and the point of the cone at the bottom is labeled: circular hole.
• A dashed line extends horizontally from the circular hole.
• The surface of the water in the tank is labeled: A_w and a line segment from the dashed line to A_w is labeled: h.
• The radius at the top of the tank is labeled: 8 ft.
• The height of the tank is labeled: 20 ft.

If the tank is initially full, how long will it take the tank to empty? (Round your answer to two decimal places.)

14.31 minutes

(b)

Suppose the tank has a vertex angle of 60° and the circular hole has radius 3 inches. Determine the differential equation governing the height h of water. Use

c = 0.6

and

g = 32 ft/s².

=  

If the height of the water is initially 11 feet, how long will it take the tank to empty? (Round your answer to two decimal places.)

Given , f'c to the power of apostrophewhat is the maximum usable strength of the concrete when designing beams?

A steel storage tank 20m in diameter will be used to hold liquid petroleum product. When filled, the tank causes a bearing pressure of 150kPa. The soil underlying the tank has a unit weight of 16.5kN/m3 above the water table and 19.8kN/m3 below the water table. For a depth of 10m below the base of the tank, compute the effective vertical stress when the tank is empty and when it is full, for points under the center and the edge. (Assume the base of the tank is on the ground surface and ground water table, GWT, is 5m below the ground surface. Ignore the empty weight of the tank).

I would like to be a civil engineering designer
What are the fundamental subjects taught in civil drafting. please what should I study first, second, third........till professional civil designer.

An asphalt rectangular channel is 7m wide and has a slope of 1° . The water is 1.5m deep. Find the discharge rate for uniform flow. What is the radius of an asphalt cylindrical channel, which is half-full, to give a similar discharge rate?

Please read the case study from your textbook - Baker v. Fennenam & Brown Properties, LLC and Southern Bells of Indiana, Inc., all d/b/a Taco Bell (pg. 175, Case Study 5 - 15).

1. Do you agree with the court's determination that Taco Bell should provide reasonable assistance to Baker even though Taco Bell was not responsible for his illness? Why or why not?

2. What is the public policy underlying the court's decision?

Conduct research on one of the first built tombs in the world. The selected tomb should have a superstructure. Specifically, focus on the, Evidential, Historical, Aesthetic and Communal Values of the tombs. In other words, determine the specific futures of a tomb in relation to their evidential, historical, aesthetic, and communal values

Architect, architectural features, construction year and duration, construction materials, construction type, structural features, construction purpose and the features that make it different and significant and the importance of the construction for the society should be included and explained under the headings of Evidential, Historical, Aesthetic and Communal Values in the report. You should illustrate your explanations with photographs which should be referred in your report.

Prepare a maximum 350-words long document

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Though steel have high tensile strength, detailing is necessary not only for the steel structures but also for the RCC members as it is the translation of all the mathematical expression’s result. For that matter, coin a comprehensive definition for detailing of reinforcement bar (steel).

A polymer rod is tested to determine its viscoelastic response. The rod’s cross-section is square with the side of 5mm. The rod’s length before loading is 500mm. A tensile force of 500N is applied to the rod and the rod’s length under load was measured as a function of time. Instantly after applying the load, the rod is stretched to 508mm. After 24 and 48 hour under load, the rod’s length was measured as 550mm and 570mm, respectively. The load was then removedand the rod’s length was measured as 525mm after a long time after the removal of the force (consider this as the permanent length). Determine the parameters of the Burger’s model for describing this type of mechanical behavior.

A wastewater treatment plant, which serves a population of 300,000 people, receives an average daily volume of 24 million gallons per day (MGD) at an average influent 5-day biochemical oxygen demand concentration of 200 mgBOD5/L and an average influent total suspended solids concentration of 220 mgTSS/L. The plant operates a primary sedimentation process that remove 65% of the incoming TSS and 35% of the incoming BOD5%. This process is followed by a secondary treatment process before discharge to the local waters.

9. What is plant average BOD5 loading? (answer will be given in the unit of !#. /01!") ,"-

10. Knowing the primary treatment BOD5 removal efficiency and the plant combined primary and secondary BOD5 removal efficiency. How much BOD5 is removed during secondary

    treatment every day? (answer will be given in !#. /01!") ,"-

11. The biomass is quantified in terms of volatile suspended solids concentration (VSS) . For example, if the content of a biological reactor has a VSS concentration of 2000 mgVSS/L, it is estimated that there is 2,000 mg of biomass per Liter of reactor.
    With that said, what will be the expected secondary treatment biomass production if the

    net biomass yield is 0.3 lb VSS/lb of BOD5 removed)? (answer will be given in !#. 633") ,"-

A wastewater treatment plant that treats wastewater to secondary treatment standards uses a primary sedimentation process followed by an activated sludge process composed of aeration tanks and a secondary clarifiers.
This problem focuses on the activated sludge process.

The activated sludge process receives a flow of 15 million gallons per day (MGD).
The primary sedimentation process effluent has a BOD5 concentration of 180 mgBOD5/L (this concentration is often referred as S). Before flowing into the activated sludge process, the primary effluent is mixed with the returned activated sludge (RAS) – concentrated biomass - that is continuously pumped out of the bottom of the secondary clarifiers. The returned activated sludge (RAS) ratio is 25%, in other word, an equivalent of 25% of plant flow (15 MGD) is pumped out of the bottom of the secondary clarifiers. The mixture of primary effluent and RAS forms make up the activated sludge, which is also called mixed liquor. The resulting mixed liquor has a total suspended solids (TSS) concentration of 2,500 mgTSS/L and a total volatile suspended solids (TVSS) concentration of 2,125 mgTVSS/L (this biomass concentration is often referred as X).
It flows into aeration thanks that have a total volume of 2.5 million gallons (Mgal) (this volume is often referred as V).

The mixed liquor then flow to secondary clarifiers that have a total volume of 5 million gallons.

Activated that settles at the bottom of the secondary clarifiers is pumped out of the tank. The majority is continuously sent back to the aeration tank as RAS but some is removed from the activated sludge process as waste activated sludge (WAS). The WAS has an average TSS concentration of 10,000 mg/L and a total mass of 10,000 lb of WAS TSS is removed every day.

The final effluent has an average BOD5 concentration of 12 mgBOD5/L and an average TSS concentration of 10 mg/L.

1. Draw a schematic of the activated sludge process and insert the different values given in the question.

2. What is the average RAS flowrate? (answer will be given in the unit of !!"#$" ?? ???) %&'

3. What is the average aeration process hydraulic detention time? Remember to include the RAS flowrate in your calculation (answer will be given in the unit of (hr))

4. What is the aeration process average BOD5 loading rate? Remember that the RAS data is

   not included in this calculation (answer will be given in the unit of ! $(*+, ")

   -... /0!1/ 23&4012 . %&'

5. What is the total mass of biomass present in the aeration tanks? (answer will be given in the unit of (lb TVSS))

6. What is the activated sludge food to microorganism (F/M) ratio? (answer will be given in the unit of ! $( *+, ") )

67 89:;; . %&'

7. The final effluent TSS is assumed to be composed of biomass that was not captured in the secondary clarification process. Therefore, the mass of final effluent TSS has to be included in the total amount of biomass removed (biomass leaving the system). With that said, what is the daily mass of TSS or biomass leaving the system with the final effluent? (answer will be given in the unit of (lb FE TSS))

8. What is the activated system sludge retention time (also called sludge age or mean cell retention time) when only considering the mass of activated sludge present in the aeration tank? (use the biomass TSS values for this question) (answer will be given in the unit of (day))

9. Based on the ”general loading and operational parameters for activated sludge process” table below, which activated process is the plant operating? (answer will be one of the 5 processes listed in the table)

10. Knowing the mass of WAS TSS removed and the WAS TSS concentration, what is the daily volume of WAS removed from the system? (answer will be given in the unit of (gallon/day))

11. Will the sludge age increase if the volume and mass of WAS removed from the system increase? (answer will be given as yes or no)

12. Will the type of bacteria present in the activated sludge and its performance likely to change as the sludge age is increased or decreased? (answer will be given as yes or no)

Environmental Engineering

Water Treatment.

Question 1:

Aeration is particularly utilized to supply oxygen in water treatment.

a) How much oxygen is required for drinking water?

b) How do the impurities (pollutants or other ions) in water affect aeration efficiency?

Question 2:  

A) How do you classify the settling types? Explain briefly.

B) Explain use of sedimentation units in water treatment (i.e. before or after which processes is sedimentation required).