1. Two reactors, one of them a CMBR and the other a CSTR, are operating side by side in parallel. Each is treating one half of a total flow rate of 800 gal/min containing a substance that enters at a concentration of 80 mg/L and experiences first-order degradation with a k value of 0.1/min.

The reactors have identical volumes of 8000 gal, so they also have equal liquid retention times of 20 min.

(a) What is the concentration of the substance leaving the CMBR?

(b) What is the concentration of the substance leaving the CSTR?

(c) Why are the two concentrations as different as they are?

2. The total flow drops to 400 gal/min, the CMBR is shut down (so all of the flow is going through the CSTR), and the influent concentration of the substance jumps to 120 mg/L.

(a) What will be the new, long-term effluent C from the CSTR?

(b) What will be the effluent concentration 5 minutes after the change?

(c) 20 minutes after the change?

Consider a 10x108 m3 lake fed by a polluted stream having a flow rate of 2.0 m3 /s and pollutant concentration equal to 10.0 mg/L. There is also a sewage outfall that discharges 0.5 m3 /s of wastewater that has a pollutant concentration of 100 mg/L into the lake. The stream and sewage pollutants have a decay rate coefficient of 0.20 day-1 (first order). Under these flow conditions the lake remains the same volume (e.g. a stream enters and exits the lake) and that the lake shallow and in an area which significant wind (i.e. always has white caps). Assume there is no evaporation or other water losses or gains.

a) Which ideal reactor would be best use mathematically model this system? Why? (1 sentence)

b) What is the steady-state concentration of pollutant in the lake under current conditions?

c) If one day the wastewater plant treatment process were to be improved, releasing a pollutant concentration of 25 mg/L at the 0.5 m3 /s (which is assumed to be become immediately completely mixed in the lake), how long would it take for the system to most nearly reach steady-state.

list construction criteria for water distribution system. design, construction and operation. from an agency.
please list refrence

hydrology. water resources

ENMA 480: ETHICS AND PHILOSOPHY FOR ENGINEERING APPLICATIONS

Cigarettes   kill   more   than   400,000   Americans   each   year,   which   is   more   than   the   combined   deaths   caused  
by   alcohol   and   drug   abuse,   car   accidents,   homicide,   suicide,   and   acquired   immunodeficiency   syndrome  
(AIDS).   Cigarette   companies   do   much   good   by   providing   jobs   (Philip   Morris   employs   more   than   150,000  
people   worldwide),   through   taxes   (more   than   $4   billion   paid   by   Philip   Morris   in   a   typical   year),   and  
through   philanthropy.   Most   new   users   of   cigarettes   in   the   United   States   are   teenagers   (younger   than  
eighteen   years   of   age).   There   is   disagreement   over   just   how   addictive   cigarettes   are,   but   adults   have  
some   choice   in   deciding   whether   to   continue   using   cigarettes,   and   they   may   choose   to   continue   using   for  
reasons   beyond   the   addictive   potential   of   nicotine.  
Can   utilitarianism   provide   a   moral   justification   for   engineers   who   work   for   tobacco   companies,   for  
example,   in   designing   cigarette- making   machinery?   In   your   answer   take   account   of   the   following   facts  
(and   others   you   may   be   aware   of).
(Roger   Roseblatt,   “How   Do   Tobacco   Executives   Live   with   Themselves?”   New   York   Times   Magazine,   March   20,   1994,   34–41,   55)

1. Explain how the following systems work:

a.

Constant-volume dual-duct system

b.

Variable air volume reheat system

c.

Fan Terminal Units

d.

Fan Coils

e.

Variable Refrigerant Flow (VRF)

f.

Radiant Heating and Cooling

g.

Chilled Beam

h.

Radian Floor System

i.

Water source heat pump

j.

Dedicated outside air system

A traffic signal has a cycle length of 90 seconds. For the travel direction of interest: (1) Green Time = 60 seconds; (2) Red Time = 30 seconds; (3) Arrival Rate = 30 veh/min; (4) Saturation Flow (i.e. the queue discharge rate) = 1 veh/sec.

a) Calculate the total delay (veh*s) for the travel direction of interest.

b) What is the maximum queue size (veh)?

Assume road works are taking place ON THE STREET, downstream from the intersection, so that only 40 veh/min (in the direction of interest) can pass. The departure from the signalised intersection will be the arrival at the work zone section. Assume that the queue at the downstream restriction never backs-up into the intersection.

c) Calculate the maximum queue (veh) caused by the street work in one traffic signal cycle.

d) Calculate the total delay (veh*s) caused by the street work in one traffic signal cycle.

Interview a program/project manager; it can be inside your organization or external to your organization, preferably this individual has more than ten-years’ experience in the profession.

ask the following:

What is your approach to managing a project?

What is your school of thought on project management? Do you prefer waterfall, agile methods etc.?

What skills does a program manager need to have in today’s market?

What is the greatest challenge as a program manager?

Where do you see program management going in the future?

How do you handle politics and conflict?

Write a 2 to 4 paragraph summary of the interview, from the above questions.

Using the regime-theory method, design a channel to carry wastewater from a manufacturing plant. Assume a design discharge of 950 ft3/s.950 ft3/s. The channel will have a sand bed and banks. Use a Manning’s roughness coefficient of 0.025.

Assume: Water Temp = 60°F, slope = 0.25%

A clean sand deposit has a total unit weight gabove the groundwater table of

18.9 kN/m3and a submerged unit weight of 9.84 kN/m3. The groundwater table

is located 1.5 m below ground surface. Standard penetration tests were

performed at 3 m below the ground surface with a blow count of 3 blows for

the first 150mm, 4 blows for the second 150mm and 5 blows for the third

150mm. Estimate the shear wave velocity of the sand at 3 m below the ground

surface. If a cone penetration test was performed at 3m below the ground

surface and the cone tip resistance was 3.9 MPa, estimate the shear wave velocity.

Compare the values obtained from both approaches.