You will hear a lecture. After listening to the lecture, in 10 seconds, please speak into the microphone and retell what you have just heard from the lecture in your own words. You will have 40 seconds to give your response.

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 参考背景: This is a bomb calorimeter, this is the actual piece of equipment that researchers used to calculate the energy content of either biodiesel or maybe even the potato chips that you had for lunch today. When they calculate the amount of energy. They’re going to calculate it in heat unites which would either be joules or calories. I want you to look inside the bomb calorimerter inside here, you can see that there’s a silver bucket water goes all in here and this is actually the bomb is the smaller silver cylinder what you do is put your fuel sample in there then these two electrodes are connected to the bomb. These provide the spark that will ignite your sample when your sample burns or combust that gives off energy. So how is the energy collected or how did a scientist figure out how much energy is being given off. Well, it’s a closed system, there’s a lid here that goes on top of this calorimeter and what’s in here in the lid is a stirrer. The stir is going to stir the water. That’s in this big pool here so that the heat given off from the sample is going to warm the water in a uniform way. This is the temperature probe, this goes down in the water also and measures the change in temperature because as the sample is burned, it will give off heat and the temperature the water will increase. So, the lid goes on the sample is prepared. The last thing that you need to make a combustion reaction happen is oxygen and at some point, during the process, some oxygen is added by a tank. That’s connected to the calorimeter here. So, we are going to burn a sample of the biodiesel that you’ve prepared and get some feedback on the energy content of it. You’ll be able to use this to compare it to petroleum-based fuels like octane.