Characterization of the Droplet Population Generated by Centrifugal Atomization Nozzles of UAV Sprayers
, Job Teixeira de Oliveira 1,*, Marcos Eduardo Miranda Alves 1, Larissa Pereira Ribeiro Teodoro 1, Fernando França da Cunha 2 and Paulo Eduardo Teodoro 1
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper presents solely experimental results but lacks corresponding theoretical analysis.
It is recommended to conduct a theoretical analysis from the perspectives of nozzle structure and fluid dynamics characteristics, in order to explain the underlying reasons for the formation of the spray characteristics observed in the two types of nozzles discussed in the text.
It is advisable to undertake a detailed comparative analysis of the experimental results presented in this paper with those of other types of nozzles, elucidating their respective advantages and disadvantages.
Comments on the Quality of English LanguageMinor editing of English language required.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsI read the manuscript entitled 'Characterization of the Droplet Population Generated by Centrifugal Atomization Nozzles of UAV Sprayers' with interest, but it has a lot of big flaws, as detailed below
- Line 14 – 18: This is too confounded. Please, make it very simple as possible
- The pattern of writing was not followed in the abstract at all…. There was no mention of the methodology at all
- A good abstract should have the following sequentially
1) The importance of the study
2) Objectives
3) Methodology
4) Results
5) Conclusion
- All these elements of a good abstract are completely missing, and this section should be re-written. Also, include quantitative values of measured parameters in the result presentation section of the abstract, just the cogent ones
- Line 29; ……………. even as UAVs (un- manned aerial vehicles) should be un- manned aerial vehicles (UAVs)
- Please, combine paragraphs 2 and 3
- Line 52; authors said the most notable and again in line 53 authors said the most commonly used … Please, there is no much difference in the meaning of these two sentences. Rewrite to make the intention clearer
- Line 66; Using this technology, a hydraulic flow provides a low flow ……. Please, this does not flow well grammatically
- The shortcoming in this study was that the introduction section lack proper documentation of previous study, which will guide or lead to the innovation of the work. Authors dwell too much on the advantages and disadvantages of spraying by hydraulic nozzles; centrifugal 52 atomization; thermal atomization; and gas atomization, including those of the droplet characteristics
- For example line 88 – 91 ………… However, recent research with this technology involves studying the flight height, effective width or application swath, and flight speed of the RPA. LiĴle has been studied about the quality of the droplet population generated by these nozzles, especially because they are recently developed ….. These is a fact also stating that recent researches, without any citation(s)
- Line 100 and 101; why was the data analyzed separately?
- Line 106 – 110; the experimental design is not clear. ….. 3 application rates and 3 hydraulic tips. This should form 9 treatments and x 5 replicates = 45 trials. This break down was not well stated
- If this is truly the combination, it can’t be a CRD, maybe you mean RCBD
- Line 156; ….. The data were subjected to analysis of variance using the RBio program …. Which data ? and to do what type of analysis ?
- Line 156; Re-sponse surfaces were adjusted using the SigmaPlot program for each test…. This is strange… can response surface be adjusted or you mean developed ?
- What test was sigma plot used for ?
- Line 158; …… significance of the regression coefficients using the t-test…. T-test is not used for regression. It is used for comparing means between two groups
- Line 159 – 160; principal component analysis was performed containing all treatments to verify the similarity between the variances and determine which variables best contributed to such similarity or disparity……………… How was the PCA carried out ? what software… was it based on rotation or not … None of this information. Moreso, nothing like PCA was mentioned in both abstract and introduction.
- Did authors test the suitability of the data-set for PCA …. This is done checking for Kaiser–Meyer–Olkin (KMO) and Barlett tests
- The results are too shallow …. Where is the means comparison result using the T-test and what significance level ? It’s missing
- Even the RSM figures lack coefficient of determination as mentioned in the methodology
- The PCA result is not deep.
- Authors need to carry out correlation analysis using Pearson correlation and determine the KMO value before PCA analysis
- What are the loading factors in each of the PC components
- What parameters were considered for the PCA, this should be distinctly presented and let the readers know which one has the highest loading factor.
Comments on the Quality of English LanguageExtensive editing required
Author Response
attached document with all the answers
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors1. Materials and methods section need to be improved. It is not explained according to the objectives
2. Statistical research plan may be given in tabular form considering independent operation parameters (height, speed, nozzle discharge, nozzle rpm, etc.) and dependent parameters such as droplets characteristics.
3. Experimental setup to test the centrifugal nozzle is not clearly explained. Kindly add a clear photo of experimental setup with labeling the different parts of control unit like, how to vary centrifugal nozzle rpm, rpm display unit, pressure variation unit or remote PWM setting, height, etc. in lab.
4. In materials and method, kindly explain clearly the experiment was conducted in lab as well as field test site with field photos of drone with centrifugal nozzles. In tile given UAV but there is no photo of UAV in manuscript.
5. Line no. 112-113, the standardized speed of 20 km h-1 (5.56 m s-1) was used to calculate the spray application rate. Please give reference of recommended calibration at 20 km/h, why not below and upper speed. Also what is the basis of this rpm range: The 11 rotations evaluated were 2,000, 3,000, 4,000, 5,000, 6,000, 7,000, 8,000, 9,000, 10,000, 11,000, and 12,000 rpm (rotations 117 per minute).
6. What is the recommended VMD for agricultural sprayer drone is the 100 to 150 um is suitable for spraying. Droplets characteristics is also depend on % coverage, density, etc. but study it is not considered
7. In centrifugal nozzle droplets particle size is very fine and chance of drift is more, what is recommended wind speed?
8. Results and discussion, conclusions should be modified according to research plan. This should be explain with effect of operating parameters of drone spraying system such height, speed, nozzle discharge, nozzle rpm, etc. on droplets characteristics.
Comments on the Quality of English LanguageIt is ok
Author Response
attached document with all the answers
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThe paper titled “Characterization of the Droplet Population Generated by Centrifugal Atomization Nozzles of UAV Sprayers” aims to characterize the droplet population produced by both hydraulic nozzles and centrifugal atomization nozzles used in sprayers mounted on remotely piloted aircraft.
Overall, the paper is well-written and presents interesting results with substantial discussions on the topic. The authors have adequately addressed the previous concerns.
Line 101-103: Consider rewriting this section to avoid repeating the abstract. Here, you could explore in more detail the research gap that this study seeks to fill.
Line 104: I suggest subdividing this section into topics, for example, 2.1 Study Area.
Figure 5: It might be helpful to slightly reduce the font size of the red text or place it elsewhere to avoid cluttering the image.
Author Response
##Reviewer: 4
Recommendation: Minor Revision
Comments:
Overall, the paper is well-written and presents interesting results with substantial discussions on the topic. The authors have adequately addressed the previous concerns.
Response: Thank you very much for your comments. The manuscript had already undergone a first round of review, and the authors believe that the comments made by the reviewers were important and were accepted.
Line 101-103: Consider rewriting this section to avoid repeating the abstract. Here, you could explore in more detail the research gap that this study seeks to fill.
Response: Thank you. A work hypothesis sentence has been inserted. The authors believe that leaving the research objective the same as the text written in the abstract is an appropriate form of presentation, so as not to promote an inadequate interpretation.
Line 104: I suggest subdividing this section into topics, for example, 2.1 Study Area.
Response: Thanks for the suggestion. The modification has been made.
Figure 5: It might be helpful to slightly reduce the font size of the red text or place it elsewhere to avoid cluttering the image.
Response: Thanks for the suggestion. The modification has been made.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsComments on the Quality of English Language
Author Response
The reviewer did not point out any specific points to be corrected or changed.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsMy major concerns about the manuscript remain the same
Comments on the Quality of English LanguageExtensive English Editing Required
Author Response
The reviewer did not point out any specific points to be corrected or changed.
Author Response File: Author Response.pdf
Round 3
Reviewer 2 Report
Comments and Suggestions for AuthorsMy concerns remain the same, especially in the aspect of KMO and Berlette analysis to test the suitability of the data for PCA. Moreso, other aspect of statistically addressed.
Comments on the Quality of English LanguageEditing required
Author Response
A KMO value of at least 0.5 is generally considered acceptable for factor analysis. However, it is important to note that we did not use factor analysis in this manuscript. We used a principal components analysis, which does not have any statistical assumptions to be performed. Therefore, we chose not to present the KMO and Bartlett tests on the manuscript because they do not test assumptions for this analysis.
Although we chose not to present the results of the KMO test in the manuscript, we have forwarded the results below. Thus, we believe that the request has been addressed.
It is also important to note that the requested person correlations were entered in graphical form (Pearson correlation analysis – Fig. 9).
Furthermore, we have added the sentence with the assumptions regarding the topic in the manuscript, so that we could adjust/adapt an address on the subject.
Thanks by the comments.
- KMO analysis for the hydraulic nozzle:
Kaiser-Meyer-Olkin factor adequacy
Call: KMO(r = data)
Overall MSA = 0.53
- KMO analysis for the centrifugal atomization nozzle:
Kaiser-Meyer-Olkin factor adequacy
Call: KMO(r = data)
Overall MSA = 0.45
- KMO analysis for the centrifugal atomization nozzle (now limiting rotation variation treatments from 5000 to 9000 RPM):
Kaiser-Meyer-Olkin factor adequacy
Call: KMO(r = data)
Overall MSA = 0.52
Yours sincerely,
Best regards
Job T. de Oliveira
Department of Agronomy
Federal University of Mato Grosso do Sul (UFMS)
