Influence of the Harvesting Region on Batch Homogeneity of Ipe Wood (Tabebuia sp.) Based on Its Physical and Mechanical Properties
, Ivanildo Amorim de Oliveira 1, Ludmila de Freitas 1, VinÃcius Borges de Moura Aquino 2, Isabella Silva Menezes 2, Iuri Fazolin Fraga 2, Francisco Antonio Rocco Lahr 3, Fernando Júnior Resende Mascarenhas 2, Fernando Menezes de Almeida Filho 2 and André Luis Christoforo 2
Round 1
Reviewer 1 Report (Previous Reviewer 1)
The authors significantly improved to manuscript with the corrections , taking into account the referee's evaluations.
Author Response
We would like to acknowledge the reviewer for his contributions and time spent reviewing our manuscript. Their suggestions were essential in making the manuscript clearer, concise, and free of spelling errors. Changes have been highlighted in red in the manuscript. All points raised by the reviewer are answered below.
Response to Reviewer 1 Comments
Point 1: The authors significantly improved to manuscript with the corrections, taking into account the referee's evaluations.
Response 1: No comment on this point.
Reviewer 2 Report (Previous Reviewer 2)
The work presented here deals with wood strength issues of the tropics. In this respect, it is an important contribution to the wood industry (wood from this zone is poorly studied in terms of mechanical and chemical properties). However, it is not a novel study; an important advantage of the presented research is the use of mathematical analysis, which allows a wider comparison of results). Figures 4,5,6,7,8,9,10 show a diagram of the specimens used in the strength tests. These diagrams are well known to mechanical strength testers especially as the authors did not attempt to modify the strength test methods.
Figure 5 is not discussed in the presented paper. In addition, the authors did not refer to Tables 2 and 3 in the text. What do the presented elements contribute to the presented paper.
Please refer to the articles:
DOI: 10.1186/s10086-020-01938-4
DOI:10.15199/62.2017.3.4
DOI: 10.5604/01.3001.0013.7640
DOI:10.5604/01.3001.0014.5967
Author Response
We would like to acknowledge the reviewer for his contributions and time spent reviewing our manuscript. Their suggestions were essential in making the manuscript clearer, concise, and free of spelling errors. Changes have been highlighted in red in the manuscript. All points raised by the reviewer are answered below.
Response to Reviewer 2 Comments
Point 1: The work presented here deals with wood strength issues of the tropics. In this respect, it is an important contribution to the wood industry (wood from this zone is poorly studied in terms of mechanical and chemical properties). However, it is not a novel study; an important advantage of the presented research is the use of mathematical analysis, which allows a wider comparison of results). Figures 4,5,6,7,8,9,10 show a diagram of the specimens used in the strength tests. These diagrams are well known to mechanical strength testers especially as the authors did not attempt to modify the strength test methods.
Response 1: The batch homogeneity condition is proposed by ABNT NBR 7190:2022. The main contribution is verifying the consideration of the batch's homogeneity. Given that Brazil is a country of continental dimensions, the sawmills receive batches from several regions, and there is no control or classification of these batches received from different areas. There are some studies on the influence of the harvesting region, and these few studies do not answer this main question since there are about 16,000 species in the Amazon Rainforest. The target readership of the journal ranges from forest to civil engineers. In addition, the journal has an international reach and possibly reaches countries that do not have their standard for wooden structures. Given this, out of caution to the readers of the journal who may not know the testing methodologies and because the standard is written in Portuguese, there is a possibility that they will not be able to consult the standard, which may impair the understanding of the paper. We hope that the reviewer understands our standpoint, and we would like, if possible, for the methodology remains in the version as evaluated. Therefore, out of preciousness and care for the readers, we believe that the description of the tests should be kept, and we hope that this will not negatively impact the evaluation of the article. As previously mentioned, the intention of this work is not to modify any of the tests proposed in the standards, but to evaluate the condition of homogeneity of batches proposed by ABNT NBR 7190. The work that questions the consideration of homogeneity of the batch were for this species analyzed. For the conditions presented in the paper. It is observed that the consideration of homogeneity of the batch failed, where we do not observe the homogeneity of the batch. Once again, we reaffirm that for numerous species, one cannot answer this question with a single study.
Finally, we point out, once again, that, as stated in the text, the difficulties of controlling the conditions for a sawmill, as highlighted in lines 395 to 403, and the difference between strength classes of the same batch, impact directly on the design of timber structures, which is the main point of this paper.
Point 2: Figure 5 is not discussed in the presented paper. In addition, the authors did not refer to Tables 2 and 3 in the text. What do the presented elements contribute to the presented paper.
Response 2: Figure 5 was discussed in the fourth paragraph on page 14. Tables 2 and 3 were referenced in the text. And the results of table 1, table 2 and table 3 were discussed and compared with correlated literature results, this being the contribution to the present paper to validate the results obtained. Being that there is no study on the influence of the harvest region on the influence of the physical and mechanical characteristics of the wood.
Point 3: Please refer to the articles: DOI: 10.1186/s10086-020-01938-4; DOI:10.15199/62.2017.3.4; DOI: 10.5604/01.3001.0013.7640; DOI:10.5604/01.3001.0014.5967
Response 3: The suggestions of references to be inserted in the paper were evaluated and the article DOI: 10.1186/s10086-020-01938-4 was cited in section 2.4.7. The rest of the suggested papers we believe are not pertinent to the paper and may be considered for citation in other papers to be developed by our research group. We hope that this will not impact the new evaluation.
Author Response File: 
Author Response.pdf
Reviewer 3 Report (Previous Reviewer 3)
The biggest problem with this publication is the proportion between the chapters. The most important results from the scientific point of view and the discussion take up only four pages of the manuscript. The methodology is the most significant part. In the reviewer's opinion, describing all determinations in such detail is unnecessary. The results are discussed very simply; they add little to the science of wood.
Author Response
We would like to acknowledge the reviewer for his contributions and time spent reviewing our manuscript. Their suggestions were essential in making the manuscript clearer, concise, and free of spelling errors. Changes have been highlighted in red in the manuscript. All points raised by the reviewer are answered below.
Response to Reviewer 3 Comments
Point 1: The biggest problem with this publication is the proportion between the chapters. The most important results from the scientific point of view and the discussion take up only four pages of the manuscript. The methodology is the most significant part. In the reviewer's opinion, describing all determinations in such detail is unnecessary. The results are discussed very simply; they add little to the science of wood.
Response 1: The batch homogeneity condition is proposed by ABNT NBR 7190:2022. The main contribution is verifying the consideration of the batch's homogeneity. Given that Brazil is a country of continental dimensions, the sawmills receive batches from several regions, and there is no control or classification of these batches received from different areas. There are some studies on the influence of the harvesting region, and these few studies do not answer this main question since there are about 16,000 species in the Amazon Rainforest. The target readership of the journal ranges from forest to civil engineers. In addition, the journal has an international reach and possibly reaches countries that do not have their standard for wooden structures. Given this, out of caution to the readers of the journal who may not know the testing methodologies and because the standard is written in Portuguese, there is a possibility that they will not be able to consult the standard, which may impair the understanding of the paper. We hope that the reviewer understands our standpoint, and we would like, if possible, for the methodology remains in the version as evaluated. Therefore, out of preciousness and care for the readers, we believe that the description of the tests should be kept, and we hope that this will not negatively impact the evaluation of the article. As previously mentioned, the intention of this work is not to modify any of the tests proposed in the standards, but to evaluate the condition of homogeneity of batches proposed by ABNT NBR 7190. The work that questions the consideration of homogeneity of the batch were for this species analyzed. For the conditions presented in the paper. It is observed that the consideration of homogeneity of the batch failed, where we do not observe the homogeneity of the batch. Once again, we reaffirm that for numerous species, one cannot answer this question with a single study.
Finally, we point out, once again, that, as stated in the text, the difficulties of controlling the conditions for a sawmill, as highlighted in lines 395 to 403, and the difference between strength classes of the same batch, impact directly on the design of timber structures, which is the main point of this paper.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report (Previous Reviewer 3)
There are still some inaccuracies in the final text.
Line 456: Turkey instead of Tukey.
Lines 320 and 326: the parameter described is hammer work, not toughness.
Line 248: perpendicular, not parallel.
Equation 14: Why is 1000 there?
Line 348: You wrote about fwk in the text, but this parameter is missing in the table.
Tables 1-3 use shrinkage symbols other than those described in the methodology.
Why is only the work performed by the hammer and not the impact strength characterised in tables 1-3?
The analysis of the results is elementary. In principle, it describes the results obtained without indicating the potential reasons for the differences.
The methodology chapter is too extensive and covers ten pages of the entire manuscript. Since the markings of parameters are made according to standards, are drawings of samples necessary? Especially since not all the samples are there, but some.
Author Response
We would like to acknowledge the reviewer for his contributions and time spent reviewing our manuscript. Their suggestions were essential in making the manuscript clearer, concise, and free of spelling errors. Changes have been highlighted in red in the manuscript. All points raised by the reviewer are answered below.
Response to Reviewer 3 Comments
Point 1: Line 456: Turkey instead of Tukey.
Response 1: The suggested change has been made.
Point 2: Lines 320 and 326: the parameter described is hammer work, not toughness.
Response 2: The suggested change has been made.
Point 3: Line 248: perpendicular, not parallel.
Response 3: The suggested change has been made.
Point 4: Equation 14: Why is 1000 there?
Response 4: It is a transformation factor to use the toughness (W) in J = N·m and b and h in mm, to obtain the factor in kJ/m².
Point 5: Line 348: You wrote about fwk in the text, but this parameter is missing in the table.
Response 5: fwk has been removed.
Point 6: Tables 1-3 use shrinkage symbols other than those described in the methodology.
Response 6: The symbols were standardized according to the methodology.
Point 7: Why is only the work performed by the hammer and not the impact strength characterised in tables 1-3?
Response 7: It was changed to flexural impact strength fbw (kJ/m²).
Point 8: The analysis of the results is elementary. In principle, it describes the results obtained without indicating the potential reasons for the differences.
Response 8: The differences between the properties can be explained due to the influence of various factors such as soil, climate, relief, humidity, among other factors. To evaluate the influence of these factors it is necessary to control the growth conditions of the species. For native forests such as Tabebuia sp it was not possible to control these factors because they were collected from the Amazon rainforest. Therefore, it is not possible to explain or indicate potential reasons for the differences. Given the objective of the work to verify the condition of homogeneity of the batch, growth conditions in the region of harvest were not observed, we hope that this will not negatively impact the reassessment of the paper.
Point 9: The methodology chapter is too extensive and covers ten pages of the entire manuscript. Since the markings of parameters are made according to standards, are drawings of samples necessary? Especially since not all the samples are there, but some.
Response 9: To reduce the methodology all figures referring to samples have been removed.
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The authors have studied the influence of three different harvesting regions of Ipe wood on some physical and mechanical properties.
The manuscript is an original scientific work, hovewer it is not well written and not very easy to follow. There are also some severe organizational problems of the whole manuscript. Under the heading of “2. Materials and Methods” (line 77-92), there are some information of “Instructions to authors”, and this section is not including any information regarding to the present study. The contents of the heading “3. Results” (line 94-307) also contain the information on Materials and Methods” instead of “Results”. The findings were not discussed sufficiently with the literature in “4. Results and Discussion” section.
There are a lot of studies in literature indicating the effects of growth region on wood properties. The only difference of this study from the others is the usage of different wood species (Ipe wood). It is well known that the growth region, growth and climate conditions of trees have a great influence on both the forest yield and the quality of timber, thereof physical and mechanical properties tree species vary significantly. From this point of view, the paper did not contain a new approach, new method or new findings for literature.
It is known that the increase in altitude significantly affects the wood density. Wood density has also significant effect especially on mechanical properties of wood. In order to evaluate only the effects of growth region, the altitude from which the wood samples were obtained should be the same or close. However, there is no evaluation in the manuscript about the altitude of the regions where the wood samples were taken.
Terminologically, it would be more appropriate to use “growth region” or “harvesting region” instead of “extraction region”.
It should be better to use the EN, ISO or ASTM standards instead of local standards.
Table 1 can completely be removed from the article by indicating in the methods section that 12 samples are used for each feature investigated in the study.
There are spelling errors in the manuscript. It should be good to have it all reviewed by a native English speaker.
Reviewer 2 Report
The work presented by the authors deals with the mechanical issues of wood. Why do authors include guidelines in the manuscript to develop the article without refuting them and fail to follow them.
I do not understand the separation of chapter 3. results in which there is information about the material and methods of analysis (which should be in chapter 2)?
Why do the authors show diagrams of equipment for testing mechanical properties that are known and standardised in relevant standards (industry, EN, etc.).
The work contains essential elements but has been done carelessly. There is a need to improve it carefully and if not in the paper then to include in the supplement the output data obtained from the measurements and used to develop the results.
Reviewer 3 Report
Lines 78-92: it’s some information from the template. Please delete it.
Material and methods: something is not ok. Please correct it.
Lines 167-168: why do you use such a big sample to determine compressive strength? Is it a square area 50 times 50 mm?
Line 173: why the load speed is in MPa/min, not in N/min?
It is better to give all sample sizes in mm, not in cm.
Figure 7: what does it mean a ”glue line”? The sample is stuck with two different samples?
The title of chapter 3.4.4 should be “shear strength”.
Is the sample to shear also stuck? Figure 8 looks like it is also some “glue line”.
Line 245: there is a mistake in We. It should be bh2/6
How many pressings do you make in Janka's hardness on one sample?
What was the weight of the impact hammer?
The publication has the wrong proportions. Too long methodology, too short description of results. The discussion is short without going into the details of the differences. There are too many details in the methodology.
