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Studies related to making bioplastic composites based on sago starch filled with microcrystalline cellulose and betel leaf extract have several advantages. Among them is the availability of materials that are renewable, biodegradable, resistant to microbial attack, and can improve mechanical properties. The stirring speed effect at the time of mixing the ingredients in producing bioplastic composites has been carried out. The raw materials used were sago starch, microcrystalline cellulose from coconut husk, extract from betel leaves, and glycerol. The composition of the mixture of ingredients is 100 g of sago starch plus 8 %w microcrystalline cellulose, 6%w betel leaf extract, and 20 %w glycerol. The variations made were in the stirring speed of the mixer: 120, 180, 240, and 300 rpm. The process was carried out in a mixer at 70 oC for a duration of 25 minutes. Several analyses were carried out related to density, Fourier transform infrared (FTIR), water absorption, tensile properties, and antimicrobial properties of bioplastic composites. The results obtained showed that all of the bioplastic composite materials were identified in groups in the FTIR spectra. The results also showed that at a stirring speed of 180 rpm, the properties of the bioplastic composite showed the best. Density and water absorption values at 180 rpm speed respectively are 1.25 g/cm³ and 62.5%. While for tensile strength and elongation at break of 1190.643 kPa and 21.1%, respectively. This result is related to the uniform distribution of microcrystalline cellulose as filler in sago starch at a stirring speed of 180 rpm. In the case of antibacterial properties, the stirring speed has no significant effect except at 300 rpm. [ABSTRACT FROM AUTHOR]

Oil palm Empty-fruit bunches (OPEB) Bio-sorbent were modified by introducing phosphate (P) into the OPEB-cellulose structure (P-OPEB). This modification effect to increasing the surface area in purpose to enhancing the adsorption amount. Adsorption of Zn(II) was keeping the optimum adsorption by P-OPEB is higher than Fe(II). On the other hand, by using OPEB bio-sorbent, Fe(II) was adsorbed higher than Zn(II), but the adsorption amount by P-OPEB is higher than OPEB which indicated phosphate modified was effected to increasing the adsorption capability of OPEB. The properties of all adsorption systems are similar, refer to the Langmuir model, and kinetic models refer to the 2nd-order kinetics model, but Fe(II) adsorption fits better with the OPEB Bio-sorbent. Besides being able to increase the adsorption capacity, P-OPEB also makes the adsorption process faster so that can be more efficient to remove Fe and Zn contaminants. [ABSTRACT FROM AUTHOR]

The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC) system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP). Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC), or at T5 = 30ºC for constant X (4.96).