Experimental Study of a Homogeneous Charge Compression Ignition Engine Using Hydrogen at High-Altitude Conditions

Round 1

Reviewer 1 Report

1.       Line number 50 Expand ICE

2.       Check English terms throughout the manuscript. Better to use English instead of other languages

3.       Change Fig. 1 with standard English terms

4.       Check line 193. Figure 1 is not related to engine setup?

5.       Modify Figure 2 with English words

6.       Check the units properly

7.       Couldn’t understand the first row in Table 3

8.       Try to add more output parameters.

9.       More explanations are required in results and discussion part.

..   Resubmit the article again with proper English.

Correct it carefully. 

Author Response

Thank you very much for all your comments and suggestions to improve the manuscript quality, we have addressed every comment and question one by one, and the results are presented below. 

Author Response File: Author Response.docx

Reviewer 2 Report

Some comments are given as follows:

1.      After a comprehensive discussion about the contributions and novelties, please, list them briefly.

2.      The structure of the manuscript is not mentioned in the introduction.

3.      The list of references does not include any paper published in Sustainability. Is your work well targeted?

4.      The bibliography may be improved, as there are 21 out of 26 references, i.e. over 80% older than 5 years. Also, there are 17 out of 26 references, i.e. over 65% older than 10 years.

5.      The theoretical contribution may be improved.

6.      Please use English in the entire article; Figs. and...

7.      Write the material formula correctly; indices and exponents.

8.      It is better to change the title of section 4 to Conclusions.

9.      The conclusion section may be improved. Please, clarify and justify future works.

10.  This version needs professional proofreading to address the grammatical errors and writing mechanics.

This version needs professional proofreading to address the grammatical errors and writing mechanics.

Author Response

Thank you very much for all your comments and suggestions to improve the manuscript quality, we have addressed every comment and question one by one, and the results are presented below. 

Author Response File: Author Response.docx

Reviewer 3 Report

1. Revise the introduction to clearly demonstrate the innovation of this study;

2. Cite relevant literatures in the order of which appeared in the text, without any confusion, such as "[8]" in Line 63 should appear before precede "[10]" in line 58;

3. The name of Figure 1 should appear below it and cannot be separated from Figure 1. Additionally, the name of table in Line 95 is missing;

4. Should “Figure 1” in Line 193 be “Figure 2”?

5. Should "(1)" in Line 317 be "(7)", and "(2)" in Line 318 be "(8)"?

6. The width of Figure 5, Figure 7, Figure 9, and Table 3 should not be wider than the width of the text;

7. Revise the format of references, such as references [4], [6], [8], [10], [14-19], [25-26], etc. Moreover, it is recommended to cite references in recent years.

Revise the English expression of the paper.

Author Response

Thank you very much for all your comments and suggestions to improve the manuscript quality, we have addressed every comment and question one by one, and the results are presented below. 

Author Response File: Author Response.pdf

Reviewer 4 Report

The manuscript, at the present form needs major changes. Therefore,  in the following, I enlist some major issues that need to be incorporated by the authors.

- The contribution is no more than a student paper. The Introduction should make a compelling case for why the study is useful along with a clear statement of its novelty or originality by providing relevant information.

- The abstract is very poorly written. 

-  Improve the literature review of the knowledge recently published in journals.

-  In order to make the proposed method understandable, authors need to add a graphical overview.

- Equation numbers are not properly defined,  after Equation (5) is again Equation (1)

-  The results should be extended because there are too many figures / graphs, but proper explanation is missing. Also many captions are missing.

- Authors need to add more key findings in conclusion and also limitations of this research.

Author Response

Thank you very much for all your comments and suggestions to improve the manuscript quality, we have addressed every comment and question one by one, and the results are presented below. 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Accept

Author Response

Thank you very much for Accept

Reviewer 2 Report

Please apply the previous comments correctly.

1.      Please include the content of the response to comment 1 in the manuscript.

2.      Enter the number of sections in the changes related to comment 2 in the manuscript.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf