Two wastewater treatment plant workers (one male and one female) are exposed to hydrogen sulfide in confined spaces in the treatment plant. The average temperature in the wet well is 25oC and the atmospheric pressure is 101.325 kPa. The recommended time weighted average air concentration for occupational exposure to hydrogen sulfide is 15 mg/m3. This concentration is based on an assumption that the individual is generally healthy and is exposed for 8 hours per day, 5 days per week, 50 weeks per year, over a working lifetime (that is from age 18 to 65 years). Assuming average body weights and inhalation rates over the working life of the individual, what is the lifetime (75 years) chronic daily exposure for each individual? Express your answers in mg/kg-day. Is the exposure greater for the manor the woman?

Go to explaination for the details of the answer.

Explanation:

In order to determine the lifetime (75 years) chronic daily exposure for each individual, we have to first state the terms of our equation:

CDI = Chronic Daily Intake

C= Chemical concentration

CR= Contact Rate

EFD= Exposure Frequency and Distribution

BW= Body Weight

AT = Average Time.

Having names our variables lets create the equations that will be used to derive our answers.

Please kindly check attachment for details of the answer.

A reheat cycle is used to increase the overall efficiency of the power plant.                            

Explanation:

The Reheat cycle is used --

1. to increase the efficiency of the turbine

2. to maintain the quality of the steam

3. to provide higher pressure ratio

The reheat cycle is used to to increase the net work output of the power plant.In reheat cycle, two turbines , one low pressure turbine and one high pressure turbine is used to increase the efficiency. The main purpose of the reheat cycle is to maintain the quality of the steam to 0.85 at the exit of the turbine.

               The figure given below shows a reheat rankine cycle.

In the cycle,

Process 1-2 is high pressure turbine

Process 2-3 is the reheater

Process 3-4 is the low pressure turbine

Process 4-5 is condenser

Process 5-6 is pump

Process 6-1 is boiler

A reheat rankine cycle is 30 -40% efficient than a simple rankine cycle.