Experimental Study on the Mechanical Properties of Friction, Collision and Compression of Tiger Nut Tubers
Tianhu Liu
Round 1
Reviewer 1 Report
In general, the language and grammar are ok. However, I would recommend that someone fluent in written English could proof-read the manuscript. Several sentences are way too long which makes the text unnecessary hard to follow. I will not point out grammar or spelling mistakes with some exceptions.
Furthermore, the practical significant of all the investigated properties of the tiger nut tubers it is not clear from the paper, but maybe obvious to some readers.
My personal preference is that the abstract contains too much detailed information. I would prefer a shorter and more concise abstract where a short background is given as an introduction, followed by the identification of the research gap, and then how the authors intend to fill this gap, which in turn is the novelty of the paper. Then a short summary of the most important results can be included.
Page 2: rows 68-70: “Chen et al. [8] measured the sliding friction coefficient, collision recovery coefficient of maize and wheat grain based on the discrete element method.” This sentence is misleading, the discrete element method was not used to measure anything, but rather to model something.
Page 4: rows 136-137: “The test was conducted using glue to bond the tuber into a flatter tuber plate and placed on the friction material…” The reviewer does not really follow this. In Figure 2 it looks like the tubers are placed directly on the friction material. Can the authors elaborate on why and how the tubers are glued to a “flatter tuber plate”. There should be an image or schematic of this setup.
Page 4: rows 146-148: “As shown in Figure 3, angle of repose tests were carried out on tiger nut tubers using cylinders made of stainless steel with an inner diameter of 60 mm, a height of 150 mm and a thickness of 1.5 mm.”. I suppose that there is a reason why stainless teel was chosen as cylinder material. This should be pointed out by the authors.
Page 8: rows 256-259: “At the same moisture content, the coefficient of friction between the tuber and the polyurethane, plexiglass, aluminium and steel decreases in that order, due to the reduced roughness of the four materials in that order.” How was the surface roughness of the materials measured?
Page 9: rows 287-289: “In order to reduce frictional damage during processing, a steel with a low coefficient of friction should be considered for the material of its working parts.” How is frictional damage defined in this case? Since friction and wear is not always related in the same direction, the steel with the lowest friction against a tuber would not necessarily be the most wear resistant.
Page 10, row 307: “effect of moisture content on recovery coefficien”. A “t” is missing in coefficient.
Page 11, row 338: 597 should be 0.597
Section 3.3.1 to 3.3.3 Given the accuracy of the force measurements described in section 2.2.3, it seems like the force values are given in too many significant digits.
Author Response
Dear Reviewer:
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Major issues:
The methods used in this manuscript are relatively common and there is little innovation. The limitation of previous methods should be presented.
Minor issues:
- Please provide references of experimental method. Please explain why they did not take rolling friction into account.
- Please explain why they need a tuber plate in Fig.2.
- There are great differences in surface shape and roughness between samples. How to prove that the experimental results are representative?
- Why they did not take maturity into account.
Author Response
Dear Reviewer:
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
This paper discussed the Influence of different factors on mechanical properties of tubers,
1. The surface roughness of four different materials should be listed respectively at line 258, page 8.
2. Blank spaces should be added between figures and units from line 466 to line 477;
3. In table 6, “2” in“R2” should be set as superscript ;
4. The format of reference 1 and 30 should be adjusted to be consistent with others.
Author Response
Dear Reviewer:
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
It is much improved now.
Author Response
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Reviewer 3 Report
Accept
Author Response
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