Improvement of Thermoacoustic engine with glass beads (end of the Rice engine era)

link to my relevant previous videos:
• How to make a thermoac...
• Themoacoustic heat eng...
• Thermoacoustic engine ...
The rice engine although performs fanatically over short run, but its long term performance is very poor. The rice gradually get soften and sticks together, blocking the movement of air. This stops the engine functionality. the rice must be replaced and the wet rice also damage the steel wool, which after several time it also must be replaced. After experimenting with several replacement material (pasta, wheat, orange peel, small grains, etc.) I notices that size of these material plays a role. a size of 3-5 mm seems optimum. to have a robust material that does not burn, I decided to replace the rice with glass beads. This produce satisfactory results. The glass beads are not going to stick together and we will not have mold inside the engine. Furthermore, I placed a stainless steel wool in the lower section of engine so that more this more rust resistant layer be the first to have contact with vapor. normal steel wool is placed on top of it.
With this the rice era is finished and now i will work to improve other aspects of the engine.
Last week Hassan defended his master thesis. Congratulations Hassan and good luck. With this my last MSc student of 2021-2022 has graduated.
Finance: N=60
subs=2119
Available budget (N): 2119-100-60*(60+1)=-1641
Storage limit: 2^ln(2119)=202,06