## 3 Results and Discussion  
### The Thermal Environment Monitoring of Enclosed Vertical-Type Composting Facilities  
A temperature rise occurs due to the decomposition of organic matter by microbes during the composting of livestock manure and serves as the best indicator of the composting process, with the optimal composting temperature being 55 to 60 \({}^{\circ}\)C [25]. For the composting period, a contour map was created using temperature data from 20 points installed inside the reactor to observe temperature changes over time and by location. The analysis focused on how the thermal environment inside the enclosed vertical-type composting facility changed throughout the composting period. On Day 0, the beginning of the experiment, the temperature range uniformly rose to between 32.0 \({}^{\circ}\)C and 35.0 \({}^{\circ}\)C. By Day 1, during the peak of the composting period, the temperature in the compost pile reached its highest, ranging from 36.7 \({}^{\circ}\)C to 67.2 \({}^{\circ}\)C. Following Day 2, the temperature gradually decreased, and by Day 7, it was measured between 28.9 \({}^{\circ}\)C and 37.2 \({}^{\circ}\)C. Based on the temperature changes according to location, the MT layer recorded the highest temperatures throughout the experimental period. The next highest layer was MB, while the B and T layers were found to be lower than the other locations. On Day 1, the deepest temperature increase, driven by the heat from the decomposition of organic matter within the compost, resulted in a difference of more than 20 \({}^{\circ}\)C between the core and the bottom part. However,  
Figure 4: Evaluation of temperature variations in layers according to grid size: (B) bottom layer; (MB) middle bottom layer; (MT) middle top layer; (T) top layer. Figure 3: Analysis of the number of grids with grid size for the grid independence test. as the composting period progressed, this variance reduced to less than 5 \({}^{\circ}\)C by the final day (Figure 5). At the start of the composting process, the temperature inside the compost pile rose due to the heat generated by microbes decomposing biodegradable material. As the biodegradable material remaining in the manure was exhausted, the temperature gradually decreased [26]. The experiment spanned 8 days, with the mixing blades inside the reactor operating continuously without any breaks, leading to a composting period that was not extended. This outcome aligned with the tendency observed in other studies using continuously stirring reactors, where the duration of composting was similarly brief [27]. In typical composting experiments, the compost located at the innermost part usually exhibits the highest temperature. However, in this experiment, the highest temperature  
Figure 5: Changes in the thermal environment inside the compost during the composting period. points were observed at two locations. This occurrence is attributed to the lower stirring efficiency at the innermost part where the axis is situated compared to other areas [28]. Nevertheless, continuous stirring is expected to maintain adequate temperature conditions for pathogen destruction, suggesting that there should not be stability issues related to pathogens [29]. Temperature variations by height indicated that the B layer was measured to have a relatively lower temperature compared to other sections, a condition attributed to the air supplied from the piping located at the bottom of the reactor. The introduction of air into the bottom part of the compost pile resulted in deviations, yet during the hottest phase, on Day 1, the lowest temperature of the B layer was recorded at 36.7 \({}^{\circ}\)C, and on the last day, Day 8, the temperature at the same spot was observed to be 35.2 \({}^{\circ}\)C. These observations suggest that the factors determining the temperature at the bottom part of the compost pile lean more towards the inflow of air and conductive heat from the bottom than the heat generated by microbial activity [30].