This research was undertaken to determine the nano–rheological behaviours of cassava starch–zinc–nanocomposite films under dynamic loading for assessing their suitability as food packaging materials in high speed transportation. The films, with thickness ranging between 15 ± 0.22–17 ± 0.13 µm, were prepared by casting mixtures of 24 g cassava starch, 45–55% (w/w) glycerol and 0–2% (w/w) zinc nanoparticles in plastic moulds of 8–12 mm depths. The effects of the nanoparticles, thickness and glycerol on the rheological properties of the films, including the Young’s modulus, creep, hardness and plasticity index were determined using nanoindentation technique. The results show that the Young’s modulus and hardness of the films varied inconsistently with glycerol concentration and nanoparticles due probably to their isotropic nature and sensitivity to slight change in load. The plasticity index was lower for 15 µm film, which absorbed 40 pNm and dissipated 0.5 pNm during loading and unloading stages, respectively. The response of the 15 µm film to creep was higher than 16 µm and 17 µm films, and this may be consequence of lower wear at higher loads. This implies that the nanocomposite film might be suitable for high speed transportation of packaged food.
Part of the book: Composites from Renewable and Sustainable Materials
The research work focus on design and construction of automatic system for integrated plant for grain beverages processing. A grain beverage processing plant is a complex system that integrates several operations (blending of soaked grains, mixing the slurry, extracting the aqueous liquid and discharging of the paste out of the machine) together and finished in one go. Incorporating an automatic system into the integrated system simplify its mode of operation. Essential design consideration, analysis and calculations were carried out in order to determine and select materials of appropriate strength and sizes for various part of the automatic system. The major parts of the automatic system includes power supply unit, transformer, filter capacitor, voltage regulator, power indicator, pre-set buttons, time controller, eprom, display unit, controllers, limiting sensor, solenoid valve and electro-mechanical switch. The system was designed to have two controllers, one interfaced with the button network and the other organized the operational time (blending, sieving and paste expelling) in minute. Results of the testing revealed that the highest machine output of 90.24 L/h was obtained from speed of 1650 rpm using the integrated machine with automated system, low value of output of 52.64 L/h was obtained from the same speed using the integrated machine with semi-automatic system. The least machine output of 32.59 L/h was obtained from the same speed using the integrated machine without the automated system. The machine output was found to be influenced by both the automatic system and machine speed. The automatic system allows efficient work flow, reduces human labor, ensure safety and hygiene product production by eliminating human interference. Also it increased the machine output by 67%, reduce operational time by 65% and completely eliminating human interference with the product.
Part of the book: Automation in Agriculture