The Effects of Moisture and Temperature on the Microwave Absorption Power of Poplar Wood

Round 1

Reviewer 1 Report

In this study, the coupling interactions between moisture and temperature on the microwave 8 absorption of poplar were investigated quantitatively under microwave heating at 2450 MHz. The literature could be improved but the research looks good overall. 

Comments for author File: Comments.pdf

Author Response

In this study, the coupling interactions between moisture and temperature on the microwave 8 absorption of poplar were investigated quantitatively under microwave heating at 2450 MHz. The literature could be improved but the research looks good overall.

Response: Thank you very much for your good suggestion to our work. We have modified some sentences in our manuscript.

Author Response File: Author Response.docx

Reviewer 2 Report

The work presented by the authors is interesting. However, in my opinion, it lacks several elements which would have enriched it. 

The authors have devoted a lot of space to microwaves in the literature review, and I believe that they should also devote space here to wood sorption and other wood properties.

The paper would support the results by using an ANOVA test to determine the significance of the differences obtained, e.g: 

DOI:10.3390/en14102968

 

The conclusions in the subsection with this title begin only with the line 303.

Articles that can enrich your work: 

DOI:10.5604/01.3001.0015.6642

DOI:10.14314/polimery.2019.5.3

DOI:10.15199/62.2018.7.13

 

 

Author Response

The work presented by the authors is interesting. However, in my opinion, it lacks several elements which would have enriched it.

Response: Thank you very much for your recognition of our research work, and for your suggestions and comments.

The authors have devoted a lot of space to microwaves in the literature review, and I believe that they should also devote space here to wood sorption and other wood properties.

Response: Thanks for your good advices to our work. We have added some literatures about the point which you suggested in our manuscript.

The paper would support the results by using an ANOVA test to determine the significance of the differences obtained, e.g: DOI:10.3390/en14102968

Response: Thanks for your good advices to our work. It is very important for our work. Actually, this study measures the deviation between the theoretical calculation and the measured value of the test via Root Mean Squared Error (RMSE). For example, in table 1, we collected 11 temperature degrees during the whole heating process. And the RMSE value is 3.47 which between the test values by genetic algorithm and the monitored practical values, the others are 3.04, 1.89, 2.59 respectively. Overall, the data of poplar microwave heating obtained by the method of genetic algorithm of anti-physics problem can fit better to the values obtained by monitored practical experiments, as shown in Figure 7.

The conclusions in the subsection with this title begin only with the line 303.

Articles that can enrich your work:

DOI:10.5604/01.3001.0015.6642；

DOI:10.14314/polimery.2019.5.3；

DOI:10.15199/62.2018.7.13.

Response: Thank you very much for your good suggestion. We have corrected our manuscript.

Author Response File: Author Response.docx

Reviewer 3 Report

This is an original article applying numerical methods to wood. I found it interesting and useful. I invite the authors to consider the following points.

1. Equation 2. There seems to be a problem with the format of ε" . Please correct.
2. Equation 6. Explain the rationale supporting the choice of this relationship. Define a_i and W.
3. Figure 1. The genetic algorithm is described schematically. It would be important to give more details on it. What exactly are the output results? What are the criteria mentioned in the logical test box? How the initial conditions are determined? This algorithm is central to this work but not enough information is given to allow somebody to repeat the experience. Without enough information for it, I do not recommend to publish this manuscript. 
4. Line 104. Instead of "longitudinal end", you could use "transverse section". Instead of "wood species", you could use "wood sample".
5. Figure 3 is quite difficult to understand. What is R.H.S. ? It is poorly or not explained. The various curves refer to which axes?
6. Lines 155-156. It is mentioned that "the moisture content of each specimen was constant during every single experiment." I have some doubts about it even if the transverse section was sealed with epoxy resin. Did you measure sample weight before and after each experiment? This would be convincing to support this assumption.
7. Figure 6. Define "H".

Author Response

  Equation 2. There seems to be a problem with the format of ε" . Please correct.

Response: Thanks, we have revised our manuscript.

  Equation 6. Explain the rationale supporting the choice of this relationship. Define ai and W.

Response: Thanks for your good comment on this point. We can see that the influence of temperature and moisture on the dielectric loss factor presents a nonlinear relationship based on the literatures report. Thus, this paper assumes that the influence of wood moisture and external temperature on microwave absorption power is a nonlinear relationship.

  Figure 1. The genetic algorithm is described schematically. It would be important to give more details on it. What exactly are the output results? What are the criteria mentioned in the logical test box? How the initial conditions are determined? This algorithm is central to this work but not enough information is given to allow somebody to repeat the experience. Without enough information for it, I do not recommend to publish this manuscript. 

Response: Thanks for your question. In the process of microwave heating wood, microwave absorbed power P has a highly coupling relationship with wood moisture content and wood temperature. In this study, genetic algorithm of physical inverse problem was used to decouple the coupling relationship between the two, that is, microwave was used to heat poplar with different moisture content and collect its temperature data in the heating process. The temperature distribution in different time and space during microwave heating of poplar samples with different moisture content was obtained, that is, the temperature distribution at any time on the left side of Equation (1) was known, the heat conduction process on the right side of Equation (1) was known, and the microwave absorption power P in Equation (1) was the only unknown parameter. Based on the physical inverse problem genetic algorithm, we iterated repeatedly (this example iterated 1000 times) to calculate P. The minimum error between the theoretical calculated temperature value and the experimental observed value is the judgment criterion of our algorithm. The initial conditions and boundary conditions of the algorithm are the same as those of the experiment.

  Line 104. Instead of "longitudinal end", you could use "transverse section". Instead of "wood species", you could use "wood sample".

Response: Thanks, we have revised our manuscript.

  Figure 3 is quite difficult to understand. What is R.H.S. ? It is poorly or not explained. The various curves refer to which axes?

Response: Thanks, we have redrawn the Figure and redefined the RHS.

  Lines 155-156. It is mentioned that "the moisture content of each specimen was constant during every single experiment." I have some doubts about it even if the transverse section was sealed with epoxy resin. Did you measure sample weight before and after each experiment? This would be convincing to support this assumption.

Response: Thanks for your comment. Our test process was very short, the treatment of specimens with different water contents was between 14.7 and 39.9s, and the temperature was controlled within 100℃. In the early pre-experiment, the weight of each specimen was reduced by less than 1g before and after treatment. Therefore, we assumed that the water content did not change.

  Figure 6. Define "H".

Response: Thanks, we have revised our manuscript.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

I believe that the authors improved their manuscript. They responded to my comments in a satisfactorily manner.