No abstract

Natural polymers such as chitosan are one of the interesting things to study or are widely used as industrial raw materials such as adsorbents, membranes, and edible films. Portunus pelagicus L. is one of the sources of chitosan from nature. The shell of Portunus pelagicus L. in Bangka Island are waste from the untapped food industry. Even though this shell can have high values because there are chitin and chitosan. Good chitosan has a high degree of deacetylation. So the research purpose of this study is to see the effect deacetylation process using a microwave. The microwave used was MARS 6 - Microwave Accelerated Reaction System (CEM) using an EasyPrep Plus vessel. Various in Microwave deacetylation process is the time at 1200 W and 100°C. The method for analyzing the structure and degree of deacetylation (DD) in this study uses Fourier Transform Infrared (FTIR) spectroscopy. The results showed that deacetylation using conventional methods for 120 minutes at a temperature 100°C had DD 76.67% while deacetylation using microwave for 40 minutes at a temperature of 100°C had a DD 77.89%. Microwave deacetylation is three times faster than conventional methods.

Noise-Assisted Multivariate Empirical Mode Decomposition (NA-MEMD) can be used for qualitative interpretation of self-potential (SP) data.  Continuous Wavelet Transform (CWT) analysis was applied to identify multiple anomaly sources from SP data.  NA-MEMD and CWT were applied to SP data for qualitative and quantitative interpretations, respectively.  The combination of NA-MEMD and CWT on SP data was used to identify the location of fractures and seepage in the LUSI embankment.  The interpretation of the result was supported by direct current resistivity.

Researchers have synthesized hydroxyapatite-based porous scaffolds by the polyurethane sponge replication methods. Hydroxyapatite was derived from waste cockle shells through the co-precipitation method. The synthesis of porous scaffolds through the sponge replication methods is carried out by absorbing hydroxyapatite slurry through the addition of PVA and then followed by heating at 900 o C to decompose the polyurethane and PVA. The best of slurry that can produce a porous scaffold in this study is the slurry that prepared through the ratio of hydroxyapatite:PVA = 80:20. The decomposition of the two polymers will leave macropores on the scaffold with an average size of 460 μm. Based on the thermogravimetric analysis, X-ray diffraction and FTIR spectrophotometer revealed that the PVA and polyurethane sponge were correctly decomposed, except for scaffolds with 40% PVA. Thus, the porous scaffolds synthesized in this study satisfies the requirements of porous scaffolds for the bone therapy process.

As an archipelago, handling plastic waste in the Province of Bangka Belitung Islands is an aspect that needs to be taken seriously. Apart from being focused on developing tourist areas, plastic waste will easily be carried to the sea and prone to be degraded into microplastics, often consumed by marine animals. This community service activity focuses on Penyak Village, Kec. Koba, Kab. Central Bangka, Bangka Belitung Islands. To solve the plastic problem in that location, the community service team conducted training for the community, especially for Pendidikan Kesejahteraan Keluarga (PKK) members, related to processing plastic waste into various recycled creations such as bags, pencil cases, and different kinds of souvenirs. The training program is carried out by providing materials and direct training to increase the understanding and skills. To broaden people's insights, the team conducted training with the Ecoplantstic start-up, which focuses on developing waste-based products. Through the evaluation, it is known that the training provided can improve the knowledge and skills of the community in processing plastic waste into various recycled creations, and several participants plan to develop the skills acquired for entrepreneurial purposes.