We have a specific concept in Mechanical Engineering. This concept describes that when entropy generation increases, then first law of thermodynamics decreases.
I want to use these sentences in abstract of a paper. There is no plot in the abstract, I only want to describe this agreement. "This concept (or result) have created a agreement between entropy generation and first law efficiency variation. This agreement means that when entropy generation increases, first law efficiency decreases."

Now, in accordance with the following figure, I used the word "agreement" in this abstract. Is this accurate? What word can replace it?

Which of the following sentences are accurate?

  • Maximum first law efficiency of thermodynamics is in good agreement with minimum entropy generation.
  • Good agreement between the maximum first law efficiency of thermodynamics and minimum entropy generation is created.
  • Good agreement between the first law efficiency of thermodynamics and entropy generation is created.


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    Welcome to ELL! Note that 1) this could have been handled more efficiently by editing your original post (there's an 'edit' link immediately underneath your tags), 2) 'paragraphing' requires a blank line between paragraphs or 2 blank spaces at the end of the line, and 3) when you are editing it is possible to post your Figure inline using the Image icon on the edit bar--I've done this for you. – StoneyB Apr 23 '15 at 18:17
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    This sentence has multiple issues, both in grammar and in meaning. I'm uncertain what you mean by "maximum first law efficiency of thermodynamics" in particular. Energy is conserved in closed systems regardless of entropy generation. I'm hesitant to offer a proper answer without clarification. My best suggestion at this point might be: "The point/condition of minimum entropy generation coincides with the point/condition of maximum efficiency." The phrase "in good agreement with" doesn't really fit here. – Jason Patterson Apr 23 '15 at 19:10

Hmm. I want to stick to grammar and not get into a discussion of physics, but I'm having trouble understanding what you're trying to say. A law of physics does not "increase" or "decrease". How can a law decrease?

Adding the word "efficiency" doesn't help. Mass/energy is conserved, period. It isn't more or less conserved.

Maybe what you're trying to say is that the efficiency of the conversion of energy from one form to another decreases as entropy increases? Understood in a certain way, that's the definition of entropy. It's not that energy disappears, but that it becomes less usable. If that's what you're trying to say, I think you need some words about "conversion of energy from one form to another".

If that's not what you're trying to say ... please clarify.

  • Hi, Yes, first law efficiency decreases and increases. Here, physical law is not considered, But efficiency is considered. – user19061 Apr 23 '15 at 21:58
  • Entropy generation and efficiency parameters changes with flow coefficient. this variations is considered. – user19061 Apr 23 '15 at 22:08
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    My point is, it's not the law that becomes more or less efficient, it's the conversion of energy between forms. I'm not a physicist, so maybe the terminology you're using is indeed the way physicists say it. But I've never read it that way, so I suspect you're either trying to translate from your native language too literally, or you're just using some awkward wording in general. – Jay Apr 24 '15 at 13:12

To describe the relationship between the point of maximum efficiency variation and the point of minimum entropy generation you might consider these words (you don't necessarily need a preposition):


occurring at the same time


accompanying especially in a subordinate or incidental way

I opted for these for two reasons:

  1. It seems that you want to convey the meaning of these things happening at the same time
  2. Both have the word agreeing listed as a synonym at http://www.thesaurus.com/

I would say that maximum efficiency variation is depending on the minimum entropy generation or in other words maximum efficiency variation is function of the minimum entropy generation for in fact we deal with a function.

This said, I would replace agreement by depending or function as the terms in the diagram are interdependent.



I want to write these two following sentences:

  1. As a result, efficiency variation in the first law of thermodynamics is dependent to the entropy generation.
  2. The point of minimum entropy generation coincides with the point of maximum efficiency in the first law of thermodynamics.

My question is: what preposition can I use to link these two sentences?

  • I don't think that the phrase "the first law of thermodynamics" should be broken up in any place; also I think that "minimum entropy generation" and "maximum efficiency variation" should stay as such - I used Google Books search and got hits on both. – Lucky Apr 25 '15 at 5:48
  • Please do not use Answers to clarify or amplify your original question. Either edit your Question (especially if you are adding another question!) or use comments to respond to other comments. – Brian Hitchcock Jun 1 '15 at 7:39

I believe the word you are looking for is correlate (v) or correlated (adj) or correlation (n)

Two variables can have a positive correlation (one increases when the other does) or a negative correlation (one decreases as the other increases).

See, for example, http://www.investopedia.com/terms/n/negative-correlation.asp

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