96Dudy D. WIJAYA97Iwan PRASETIYOEstablishment of a space-based atmospheric water vapour monitoring system for hydro-meteorological disaster management in Indonesia(Project 2020)Development of Sound Absorber based on Oil Palm Empty Fruit Bunch (OPEFB) for Low Frequency Absorption(Project 2020)67Hydro-meteorological disaster in Indonesia may appear into many different forms such as floods, flash floods, drought, severe weather, extreme waves, forests and land fires. It is widely known that climate changes become the main driving factor behind hydro-meteorological disaster. In order to mitigate the potential disasters, it is necessary to thoroughly observe, monitor and investigate long-term climate changes over the Indonesian area. Since atmospheric water vapour plays a crucial role in the global climate changes, hydro-meteorological disaster management may therefore take advantages if long-term variations of water vapour can be accurately observed and monitored. The main goal of the proposed research is to establish a space-based atmospheric water vapour monitoring system for hydro-meteorological disaster management in Indonesia. The system will exploit the data from space geodesy and will be designed to routinely estimate and monitor long-term variations of water vapour. Once the system has been fully operational, it will then be a complementary part for the Indonesian Early Warning System. It is important to point out here that realizing the system into practice requires some optimal methods for processing and analyzing the space geodetic data over the equatorial region of Indonesia. Therefore, the proposed research will be first focused to develop new and optimal methods for the data processing and analyses.The objective of this research is to develop sound absorbers based on natural fibers which are extracted from Oil Palm Empty Fruit bunch (OPEFB). It has been known that Indonesia is the number one country in producing oil palm in the world so that the palm plantation waste can be problematic. Moreover, porosity characteristics of proposed absorber will be investigated through SEM technique, theoretical and experimental works to observe the presence of kinematic porosity (open porosity) and non-kinematic porosity. Considering both porosities, the role of each porosity in absorption performance is expected to be more clearly. Meanwhile, chitosan bio-binder is introduced to bind the OPEFB fiber to form composite absorber while its composition in solution is varied. This is of importance to observe its effect on non-kinematic porosity forming in the composite absorber. It is found that the composite absorber performance is good where sound absorptions of 0.7 and above are pronounce in frequency of 1000 Hz – 6300 Hz. The non-kinematic porosity is mostly present in the form of microstructure closed pored while dead-end pores cannot be totally formed by the chitosan bio-binder. Moreover, resonance absorption due to the non-kinematic porosities is weakly coupled with absorption mechanism of kinematic porosities so that combination of both porosities leads to lower performance. The current progress shows that low frequency performance can be enhanced by increasing composite thickness. Apart from this, the dead-end pores are still potential to alleviate poor performance at low frequency which has been demonstrated theoretically.
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