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Sedaia [141]
3 years ago
10

In the 1960s through 1980s, a medical filter manufacturer in Ann Arbor discharged 1,4-dioxane (an industrial solvent) directly i

nto the environment, where it ultimately leached into underlying groundwater aquifers. A plume of 1,4-dioxane has been spreading under Ann Arbor and could pose water quality risks if it reaches Barton Pond, which supplies 85% of the city's drinking water.
a) Barton Pond contains 1.5 billion gallons (5.68 million m3) of water and initially contains no 1,4-dioxane. Assume the pond is perfectly mixed with one stream flowing in and out at a rate of 1 m3/s. Suppose the plume enters the pond at a rate of 0.1 m3/s and contains 50 mg/L of 1,4-dioxane, which has a first-order decay constant of 6.4*105 s1. What is the steady-state concentration of 1,4-dioxane in the pond?

b) Local water authorities find a way to divert the plume such that 1,4-dioxane is no longer entering the pond. How long will it take for the 14-dioxane concentration in the pond to reach the Michigan Department of Environmental Quality's new allowable drinking water level of 7.2 ug/L?

c) The EPA classifies 1,4-dioxane as a probable carcinogen with a potency factor of 0.011 (mg/kg/d)1. If the water contains the EPA's allowable limit of 7.2 μg/L of 1,4-dioxane, calculate the carcinogenic risk based on the default EPA exposure factors over a lifetime for ingestion of potable water in an average adult. Is the water safe to drink based on the "rule of thumb" discussed in class?
Engineering
1 answer:
stepladder [879]3 years ago
5 0

Answer:

<u>Option-</u> C

  • In the 1960s through 1980s, a medical filter manufacturer in Ann Arbor discharged 1,4-dioxane (an industrial solvent) directly into the environment, where it ultimately leached into underlying groundwater aquifers. A plume of 1,4-dioxane has been spreading under Ann Arbor and could pose water quality risks if it reaches Barton Pond, which supplies 85% of the city's drinking water. So, we can evaluate the given information by concluding that the  EPA classifies 1,4-dioxane as a probable carcinogen with a potency factor of 0.011 (mg/kg/d)1. If the water contains the EPA's allowable limit of 7.2 μg/L of 1,4-dioxane, calculate the carcinogenic risk based on the default EPA exposure factors over a lifetime for ingestion of potable water in an average adult. Is the water safe to drink based on the "rule of thumb" discussed in class?                                      

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Ldentiy three industries that often need the skills of mechanical engineers. Briefly explain the skills that mechanical engineer
const2013 [10]

Answer:

3 industries that often need the skills of mechanical engineers are:

  • Automotive industry
  • Construction industry
  • Aerospace industry

The key skills mechanical engineers bring to these industries are effective technical skills, the ability to work under pressure, problem-solving skills, creativity and teamwork.

Explanation:

Automotive industry: The skills mechanical engineers bring to automotive industry include designing new cars for development, conducting laboratory testing for performance safety, and troubleshooting design or manufacturing issues with recalled vehicles. Automotive engineers have:

  • good mathematical skills, for instance in calculating the stresses power trains and other parts have to withstand;  
  • understanding and application of principles of physics and chemistry to properly design engines, electrical systems and other car components;  
  • good computer skills, because 21st century engineers rely on computer-assisted design software;
  • knowledge of ergonomics, which is applied in the process of designing a car so that the driver and passengers have a comfortable and functional environment, is another skill mechanical; engineers need.

Construction industry: Mechanical engineers are responsible for designing, building, establishing, and maintaining all kinds of mechanical machinery, tools, and components in the construction industry.

Aerospace industry: Mechanical engineers in aerospace industry produce specifications for design, development, manufacture and installing of new or modified mechanical components or systems. They design more fuel-efficient aircraft that cut emissions and build the fleets of satellites that power modern GPS technology.

4 0
3 years ago
Test question for my account
Ierofanga [76]

Answer:

Well, I hope your account is working good now :)

5 0
3 years ago
While out on the International Space Station, an engineer was able to gather a sample of a new type of unidentified rock. What k
kvasek [131]

Answer:

geology and engineering

Explanation:

In this specific scenario, the engineer would use all of his geology and engineering knowledge in order to discover some of the potential uses. This is because the field of geology focuses on understanding rocks and all the minerals that make up that specific rock. While engineers focus on finding new ways to get certain tasks done through new technology and resources. By putting his/her knowledge of both of these tasks, the engineer can quickly determine the potential that the newly discovered rock has and the value that it can bring.

3 0
3 years ago
Read 2 more answers
A particle moves along a circular path of radius 300 mm. If its angular velocity is θ = (2t) rad/s, where t is in seconds, deter
uysha [10]

Answer:

4.83m/s^{2}

Explanation:

For a particle moving in a circular path the resultant  acceleration at any point is the vector sum of radial and the tangential acceleration

Radial acceleration is given by a_{radial}=w^{2}r

Applying values we get  a_{radial}=(2t)^{2}X0.3m

Thus a_{radial}=1.2t^{2}

At time = 2seconds a_{radial}= 4.8m/s^{2}

The tangential acceleration is given by a_{tangential} =\frac{dV}{dt}=\frac{d(wr)}{dt}

a_{tangential}=\frac{d(2tr)}{dt}

a_{tangential}= 2r

a_{tangential}=0.6m/s^{2}

Thus the resultant acceleration is given by

a_{res} =\sqrt{a_{rad}^{2}+a_{tangential}^{2}}

a_{res} =\sqrt{4.8^{2}+0.6^{2}  } =4.83m/s^{2}

8 0
3 years ago
Jerry wants to manufacture flat metal sheets. Which process will he use?
Marina CMI [18]
Option choice d is the correct answer
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