Parameter Calibration of Pig Manure with Discrete Element Method Based on JKR Contact Model
Round 1
Reviewer 1 Report
It is an interesting paper! The description of the design, Materials and Methods and Results is very complete but there are a lot of errors in the English language, which need to be improved. The paragraph “Discussion” must be added to provide a scientific cut to the manuscript. Please, add this type of information: “What is the novelty of this work? What did you have done different or better than other authors?” Please add a discussion of the results because it is mandatory to provide a scientific cut to the manuscript and not simply a presentation of the results.
Abstract
Please rewrite the abstract following the guidelines of the journal: “The abstract should be a total of about 200 words maximum. The abstract should be a single paragraph and should follow the style of structured abstracts, but without headings: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used. 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article: it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions”. In particular, the abstract should be a single paragraph! Moreover, the sentence “In order to introduce the discrete element method (DEM) into the research of 5 pig manure processing machinery (i.e. high-speed fermentation machine, organic fertilizer drying 6 equipment, scraping cleaner, etc).” is not clear. Please do not use a number to introduce a sentence; in this case, write three instead of 3.
Introduction
Line 31. Please, explain why the fermenting condition of pig manure could not be studied.
Line 43. Please, write force instead of Force.
Lines 45-49. Re-write this information because it is not clear and easy to understand. Please, use a more scientific way to explain this situation.
Lines 53-55. Please re-write this sentence to make it clearer, not using “sees” but a more scientific term like “shows”.
Materials and Methods
In general, in this paragraph it is necessary to describe the pigs more precisely and accurately. What were their weights? What was their diet? Please write additional information in this section (pig health, age, access to water, etc.).
Lines 66-68. Please, move this part in the paragraph “Results” because the water content is already a result.
Line 85. Please write equipment with the capital letter.
Line 94. Remove “so as”.
Line 98. Add “are”. And the average size of pig manure of different shapes and sizes ARE shown in Table 2.
Line 100. Add more information in the caption because a figure or a table should be interpreted alone, regardless of the text. I would suggest, at least in this first table, to write the acronyms in full.
Lines 101-102. Please, re-write these sentences: “In Table 2, L, W and H mean length, width and height. HoP and T mean height of pyramid (HoP) and thickness, as shown in Figure 4”. They are confused and unclear.
Line 115. Please, write used and not uesd. Be careful!
Line 116. Change “as shown in the Figure 6 and Figure 7” to “as shown in the Figures 6 and 7.”
Line 126. Change the sentence: “The general equation of the gaussian distribution is equation (1), ?0, ?, ?, ?? all are constant” to “The general equation of the Gaussian distribution is equation (1), in which ?0, ?, ?, ?? are all constant”.
Line 134. Water content? What is centent?
Lines 138-140. Please, rearrange this sentence more clearly, for example: “Considering that the physical characteristics of pig manure and soil are relatively similar, reference can be made to the literature on the calibration of parameters of discrete soil elements”.
Results
Lines 152-154. This information: “Minitab is used to carry out the Plackett-Burman experiment design. Then, EDEM, the discrete element simulation software, is used to simulate the parameters of each group, and the simulation result of AoR is obtained” must be moved in the paragraph “Materials and Methods”.
Lines 154-155. Please, join the two sentences in a more scientific way: “The experiment design results of simulations are shown in Table 4. In Table 4, the meaning of each alphabet is shown below”.
Lines 155-159. I would suggest adding the letters of the alphabet already in the Table 3 to make the results easier to be read.
Table 5. Please, write constant with the capital letter.
Lines 167-176. Please, check this whole section because there are several double spaces between some words. Moreover, change the comma to the dot after the term "test" in line 171.
Line 188. Write box-behnken test with the capital letters.
Table 7. Write the acronyms DOF, SSAdj and MSAdj in full.
In general, add the paragraph “Discussion” following the guidelines of the journal: “Discussion: Authors should discuss the results and how they can be interpreted in perspective of previous studies and of the working hypotheses. The findings and their implications should be discussed in the broadest context possible and limitations of the work highlighted. Future research directions may also be mentioned. This section may be combined with Results”. Conclusions: This section is not mandatory but can be added to the manuscript if the discussion is unusually long or complex.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
TITLE: Parameter Calibration of Pig Manure with Discrete Element Method Based on JKR Contact Model
GENERAL COMMENT
I found the paper to be interesting. I think the authors have tried to put their findings into context and my suggestions are for clarifications.
MINOR COMMENTS/CLARIFICATIONS
[line 17] expermental → experimental
[line 20- Keywords] Please, include Discrete Element Method (DEM); in the same vein, you should add the acronym of Angle of Repose (AoR).
[line 81] Figure legend 1. Please, specify. For example, Experimental equipment. Barrel.
[line 85] Figure legend 2. Please, specify. For example, simplified experimental equipment. Barrel.
[line 115] uesd → used
[line 115] Version of Photoshop. Please, include Photoshop and version to references.
[line 116] Version of Matlab. Please, include Matlab and version to references.
[line 120] Version of Origin. Please, include Origin and version to references.
[line 152] Version of Minitab. Please, include Minitab and version to references.
[line 152] Version of EDEM. Please, include EDEM and version to references.
[line 182] Determine?
[line 188] Table 7. a2, b2, c2 → a2, b2, c2
ENGLISH LANGUAGE AND STYLE
Moderate English changes are required.
Author Response
Please see the attachment
Author Response File: 
Author Response.docx
Round 2
Reviewer 1 Report
The manuscript is much improved and needs only other minor modifications. Good job!
Abstract
Line 6. Please add “and” between engineering and many pigs.
Introduction
Line 31. Please, add a dot after fermenting machine and introduce the next sentence with “indeed”. Indeed, the temperature of pig manure can not be studied directly, because it may reduce the accuracy of simulation.
Line 34. Please, write DEM in full for the first time, as in the abstract.
Line 41. Please, write only Johnson et al. [the reference number], without date and without the names of the other authors.
Lines 91-96. Please delete “and” at the beginning of the sentence and delete the dot after results to connect the two sentences.
Materials and Methods
Lines 111-112. Please write the verbs in the past simple. “The pigs were hybrid sows, the average weight of pig was about 200kg, and the feed was mixed feed for pregnant sow”.
Line 154. Please write equipment with the capital letter: “Equipment” and not “equipment”.
Lines 172-173. Please, I have asked to re-write the sentence: “In Table 2, L, W and H mean length, width and height. HoP and T mean height of pyramid (HoP) and thickness, as shown in Figure 4” and not to duplicate it. Please delete it in one of the two places.
Line 188. Delete “In gaussian distribution” because it is a repetition.
Line 192. Please write Figures and not Figure.
Discussion
Please, delete the numbers 1-5 and connect the various sentences in a single paragraph.
Line 332. Please connect the two sentences without the dot between simulated and the simulated. Lines 350-359. Please rewrite these sentences because there are unclear and difficult to understand.
Author Response
Please see the attachment
Author Response File: Author Response.docx
