Solution of Dirichlet Pure Diffusion Problem Using Galerkin Method | | Author : Goh Rui Zher | | Abstract | Full Text | Abstract :Dirichlet pure diffusion problem refers to physical problem which only includes diffusion effect on the transport of variable within a continuum. It can be solved by central differencing finite volume method with good accuracy, provided that sufficient grids are prescribed. However, the solution using finite volume method may have high computational cost when the large number of grids takes place. Hence, in this study, Galerkin method is used as an alternative to solve the Dirichlet pure diffusion problem. Galerkin method is a numerical approach used to obtain numerical approximation by converting a continuous operator problem such as differential equation to a discrete problem. However Galerkin method is proven not to be a good tool for solution of this higher order partial differential equation physical problems due to its low accuracy, high complexity and unsatisfactory accessibility. |
| Water-in-Diesel Nano-Emulsion: A Preliminary Study on Its Formation and Short Term Physical Stability | | Author : Boon Hao Loh, Siti Nur Fadhilah Zainudin, Lih Jiun Yu, Khang Wei Tan | | Abstract | Full Text | Abstract :Water-in-diesel nano-emulsions were developed using blended nonionic surfactants i.e. Span 20 and Tween 80 in this study. With optimal HLB number (i.e. 11.16), emulsions with varying water wt% (2 wt% - 8 wt% of water, at 6 wt% surfactant) and varying surfactants wt% (2 wt% - 8 wt%, at 5 wt% water) were particularly studied for their characteristic size. From the results obtained, droplet size increases with the increase of water wt%, but generally decrease with increase of surfactant wt%. Water content ranging from 2 wt% to 5 wt% were prepared for short term physical stability study. Generally, no phase separation was observed. Neither significant increase nor decrease in term of droplets size was recorded for emulsions prepared at 2 wt% and 3 wt% of water, after 15 days of storage at room condition. |
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