You are an engineer at a power plant that creates large volumes of hot waste water, which disrupts the ecosystem of the river it drains into. Another part of the plant requires warm oil, and the plant uses large amounts of energy to heat it. Inspired by countercurrent exchange in whales, you save energy and benefit the environment by

Question

A.  running the oil pipes under the river after dumping in the hot waste water
B.  running the oil pipes around the waste water pipes, to allow heat transfer from water to oil
C.  running the waste water and oil through a single pipe
D.  adding a sensor, integrating center and effectors to control temperature in both pipes

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?

Gather Content
What do you already know about countercurrent exchange? What other information is related to the question?

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?


Answer 1

B.  running the oil pipes around the waste water pipes, to allow heat transfer from water to oil

Clarify Question
What is the key concept addressed by the question?
        · This question is asking how the principle of countercurrent exchange can be used in a non-biological setting.
What type of thinking is required?
        · Apply level:
            o You are being asked to take what you already know and use, or apply, it to the use of countercurrent exchange.

Gather Content
What do you already know about countercurrent exchange? What other information is related to the question?
        · Countercurrent exchange is seen in many different species, from fish to mammals.
        · Countercurrent exchange allows the transfer of heat or a substance from blood moving in one direction to blood that is moving in the opposite direction.
        · Efficiency is maximized by the use of countercurrent exchange.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · If the oil and wastewater were traveling in the same pipe, each would become contaminated.
        · Running the pipe under the river would not serve any constructive purpose.
        · The sensor, integrating center, and effectors are components of feedback loops of living things. While similar items could be utilized here, they do not exemplify countercurrent exchange.
        · If the pipe that carries the hot wastewater out of the plant could be placed in close proximity to the pipe that directs the oil that needs to be warmed into the plant, heat would transfer from the hot wastewater pipe to the oil pipe over the entire distance that the two pipes are parallel.

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        · Apply level:
            o Answering this question correctly depended on your ability to use countercurrent exchange in a new situation. If you got an incorrect answer, did you remember that countercurrent exchange allows heat to be transferred from one vessel to another, or that it maximizes efficiency? Did you have trouble extending countercurrent exchange to determine the correct answer?