S. Mollazehi; H. Sadrnia; M. R. Bayati
Abstract
Introduction In recent decays, the microwave heating treatment is one of the best ways for the pest control. It is difficult to determine temperature in different parts of materials by Thermometer, but we can solve this problem by Comsol Multiphysics Software. In a research, results of a farm test were ...
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Introduction In recent decays, the microwave heating treatment is one of the best ways for the pest control. It is difficult to determine temperature in different parts of materials by Thermometer, but we can solve this problem by Comsol Multiphysics Software. In a research, results of a farm test were consistent with laboratory data and high temperature area was belonged to the outer part of wooden piece (Massa et al., 2015). The numerical simulation of Microwave heating was successfully done for fruits and compared with experimental measurement in two cylindrically and spherically states by Zhao et al. (2011). The results indicated that, the temperature prediction in a wooden piece under heating of a Microwave system was in conformity with experimental infra-red rays data (Rattanadecho, 2006). The outer part of the piece was impressed by inspired heating and the inner part by transmission of heating (Massa et al., 2011). A high frequency structure simulator software, a radiant trumpet shaped antenna with 2.45GHz frequencies, 100 watt electric power were the tools that were used to predict the temperature at a Date Palm Wooden piece at 10, 12, 14 and 16 centimeters (Al Shwear and Remili, 2016). Microwave pretreatment was studied with two factors of Microwave radiation (170, 450, and 850 W) and Microwave duration (2, 6, and 10 min). It can be concluded that the Ozonolysis is the most effective pretreatment regarding to saccharification percentage of sugarcane bagasse (Eqra et al., 2015). This study has been done with the aim of fighting with Rhynchophorus ferrugineus blight by microwave and removing toxins in crops. Materials and Methods Samples features such as physical, mechanical and magnetic once were established in both Tehrans Material and Energy lab and Polymer and Petrochemical Research Center, Then it was simulated by Time_ Temperature profile software. For simulating research by Comsol Multiphysics software, at first sample and chamber sizes were determined and the type of material, meshing, 2.45GHz frequencies and the time duration of heating were measured, respectively. Finally the research was analyzed and Time_Temperature profile which was one of the outcomes of Multiphysics software was determined. A cubic piece of wood (103×86×78 mm) (Fig. 1), a Digital Thermometer and a Microwave are the tools which the researcher used in this sample. The temperature was measured at three different parts of cub diagonal by Thermometer. At first, the wooden sample was divided in two equal parts and a sensor was placed in the middle of it and then it was placed in the Microwave. The primary temperature of sample and Microwaves was 27°C. We turn the Microwave on for a period of 10 minutes, after that we check the wooden piece temperature by Thermometer at 20 seconds intervals. Results and Discussion T-test was used to compare statistical results achieved by simulated and experimental temperature of cubic diagonal. According to T mark at 5 percent level, we can say that there is a significant difference between simulated and experimental temperature at point1, however, there is no such a significant difference at 2 and 3 points. In the following phase, the temperature was compared at two simulated and experimental states by variance analysis test. There was significant difference at 1, 2 and 3 points according to data are shown at figure 4. Moreover, Duncan Post hoc test is shown at figures 5 and 7 that experimental temperature shows no difference at 1 and 3 points but it makes difference at 1, 2 and 2, 3 points. Conclusion Results show that the simulation model can predict the temperature in different parts of a wooden sample. The temperature will be higher as much as the points will be closer to the wave producer resource. In order to control pests in the trunk of a tree, we should use several wave generator systems, instead of ones. It is recommended that cylindrical microwave should be simulated and designed instead cubic ones, because it is better adjusted with tree stock and the wave generator system is placed on this surface so that the temperature will be distributed symmetrically along the diagonal.
