Distance from one end of water surface (m) |
depth of water(d) , (m) |
Immersion of current meter below water surface (m) |
||
depth (m) |
sec |
rev |
||
0 |
0 |
— |
— |
— |
2 |
1 |
0.6 |
10 |
40 |
4 |
2.2 |
0.44 |
36 |
48 |
1.76 |
20 |
50 |
||
6 |
4 |
0.8 |
40 |
57 |
3.2 |
30 |
53 |
||
8 |
8 |
1.6 |
46 |
59 |
6.4 |
33 |
57 |
||
10 |
4.2 |
0.84 |
33 |
51 |
3.36 |
29 |
49 |
||
12 |
2.5 |
0.5 |
34 |
52 |
2 |
29 |
53 |
||
14 |
1.2 |
0.72 |
16 |
48 |
16 |
0 |
— |
— |
— |
Rating equation of current meter: v = 0.2 N + 0.04, where N = rev./sec, v = velocity (m/sec).
In: Civil Engineering
The following are average operating data from a secondary activated sludge:
Wastewater flow = 29160 m3/d
Vol. of aeration tanks = 8400 m3
Influent SS = 120 mg/L Influent BOD5 = 170 mg/L
Effluent SS = 22 mg/L Effluent BOD5 = 20 mg/L
Volatile fraction of mixed liquor and effluent suspended solids is 0.65.
Mixed liquor suspended solids = 2500 mg/L
Waste sludge flow = 200 m3/d SS in Waste sludge = 9800
mg/L
Determine the following:
Aeration period, Food to micro-organisms in kg BOD/kg MLVSS /d, Volumetric BOD Loading ,Sludge age ,Observed yield in gVSS/g BOD5 ,True yield in gVSS/g BOD5 assuming a kd of 0.05 d-1 ,Daily oxygen demand
In: Civil Engineering
Please determine the dimensions and air flowrate required for a 3m deep aerated grit chamber designed to remove 70% of 0.02 cm diameter sand [specific gravity = 2.65] at 20ºC. Assume that only particles of 0.001 cm will be scoured away. The wastewater flow rate is 10000 m3/d. Use a b of 0.04 and f of 0.03 for calculations.
In: Civil Engineering
Consider a vapour
compression refrigeration cycle
that uses R-134a as
refrigerant. The R-134a
enters the compressor
as a saturated
vapour at 200 kPa,
and exits the
condenser as a
saturated liquid at
900 kPa. The rate
of refrigeration of
the cycle is to
be 6.0 tons of
refrigeration (1 ton
of refrigeration =
3.517 kW). The
compressor isentropic
efficiency is 80%.
Determine: a) The temperature
of evaporation and
condensation of the
refrigerant; b) Mass flow
of the refrigerant
R-134a, in kg/min; c)
Coefficient of Performance
(COP) of the
refrigeration cycle. Typical
vapour compression
refrigeration systems use
a throttling valve
(or an orifice
tube, or a
capillary tube) to
reduce the liquid
refrigerant’s pressure. This
is a highly
irreversible process. If
the cycle efficiency
is to be improved
by replacing the
throttle with a
rotary expander with
70% isentropic efficiency,
d) What is
the new COP? The
expander delivers its
work developed to
the compressor.
In: Civil Engineering
In: Civil Engineering
A field test is conducted in a confined aquifer by pumping a constant discharge of 14.9 m3/hr from 20-cm-diameter well. After an approximate steady state is reached, a drawdown of 0.98 m is measured in the pumped well. Also measured are drawdowns of 0.73 m, 0.65 m, 0.60 m, and0.57 m, respectively, at 8.0 m, 30.0 m, 80.0 m, and 132 m from the pumped well. Determine the transmissivity of this aquifer. Also, determine how far away from the well you must be before the drawdown becomes less than 0.45 m.
In: Civil Engineering
Explain, with reasons, whether you can use the following tests to simulate the behavior of sand in liquefaction
i) Unconsolidated Undrained Triaxial Test
ii) Direct Shear Test
iii) What is the most suitable type of triaxial test that should be used? (Does not have to be (i) or (ii))
In: Civil Engineering
QUESTIONS:
Design a square column footing for a 20-in. square tied interior column that supports loads of DL (170) k and Live load LL (210) k. The column is reinforced with eight No 8 bars, the bottom of the footing is 5 foot below final grade, and the soil weighs 100 lb. /ft3 the allowable soil pressure is 4 w ksf. The concrete strength is 4,000 psi and the steel is Grade 60.
In: Civil Engineering
Environmental lapse rate = 0.1 degree C/100m upto 100 m altitude (surface temperature drop at nighttime).
Environmental lapse rate = -0.7 degree C/100m after 100 m altitude
The adiabatic lapse rate is based on moist air.
Find the atmospheric condition from the example below.
a) Mixed radiational inversion
b) Radiational inversion
c) Subsidentail inversion
d) Frontal inversion
e) Advective inversion
Will upvote, thanks in advance
In: Civil Engineering
A Class I two-lane highway is on level terrain with passing permitted throughout. The highway has 3.6 m lanes with 1.1 m shoulders. There are 13 access points per kilometer. The base FFS is 96.5 km/hr. During the peak hour, 500 vehicles are traveling in the analysis direction and 400 vehicles are traveling in the opposing direction. If the PHF is 0.8 and there are 7% large trucks, 7% buses, and 7% recreational vehicles, what is the level of service?
In: Civil Engineering
The rate of change of the grade of a parabolic summit curve is 0.5%. The grade of ascending and descending tangents are 6% and -2.0% respectively. The elevation of VPT is 200 ft at Sta 15+80. Determine the:
a) length of curve;
b) elevation of the summit,
c) location of the summit;
d) the vertical distance from VPI to the curve;
e) elevation at Sta 06+80.
In: Civil Engineering
Give reason:
why when velocity across a pipe fitting increases the pressure drop also increases.
In: Civil Engineering
For a coastal area, you are asked as the responsible sanitary engineer to design a waste treatment plant. Briefly select the following and give a sound engineering justification: Effluent treatment train, Sludge treatment train, Effluent reuse/recycle/reclamation or ultimate disposal, Treated sludge usage or final disposal, Location of your suggested wastewater treatment plant, and Methods to be used for unit engineering design
please solve this question with a clear hand writing
In: Civil Engineering
In: Civil Engineering
A speed field; It is defined by V(u,v)=(V1/L)(-xi+yj) , here V1 and L are fixed. This flow is 2 dimensional and stable.
(a)In which position in the flow area does the velocity equal the velocity V1? Make an outline of the speed field by drawing arrows for x>=0 , these arrows should represent fluid velocity in representative positions.
(b)Draw the flow line. (dx/u=dy/v)
In: Civil Engineering