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Hasil Pencarian

Ditemukan 2 dokumen yang sesuai dengan query
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Sepehr Sadighi
Abstrak :
In this research, based on actual data gathered from an industrial scale vacuum gas oil (VGO) hydrocracker and artificial neural network (ANN) method, a model is proposed to simulate yields of products including light gases, liquefied petroleum gas (LPG), light naphtha, heavy naphtha, kerosene, diesel and unconverted oil (off-test). The input layer of the ANN model consists of the catalyst, feed and recycle flow rates, and bed temperatures, while the output neurons are yields of those products. The results showed that the AAD% (average absolute deviation) of the developed ANN model for training, testing, and validating data are 0.445%, 1.131% and 0.755%, respectively. Then, by considering all operational constraints, the results confirmed that the decision variables (i.e., recycle rate and bed temperatures) generated by the optimization approach can enhance the gross profit of the hydrocracking process to more than $0.81 million annually, which is significant for the economy of the target refinery.
Depok: Faculty of Engineering, Universitas Indonesia, 2018
UI-IJTECH 9:1 (2018)
Artikel Jurnal  Universitas Indonesia Library
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Rini Kusumawardani
Abstrak :
A series of cyclic triaxial tests at very low frequency was carried out on unsaturated clean sand in order to quantitatively investigate the influence of the degree of saturation on dynamic response. The conventional triaxial testing apparatus, which is usually used on saturated soil, was employed to test the unsaturated soil with the additional pore air pressure controller. During the series of tests, four different degrees of saturation level (Sr = 55%, 70%, 85%, 98%) were applied to the soil specimen based on a single value of effective confining pressure (?’3). The results revealed that the application of cyclic loading at a very low frequency occurring continuously triggered the decrease of soil resistance. For degree saturation, Sr = 55% revealed that the resistance of soil was stronger in comparison to another level. Furthermore, the experimental results confirmed that applied cyclic loading induced a change in saturation level before and after testing. In addition, at a certain level of saturation, a phenomenon of settlements was likely to occur and the soil specimen then underwent liquefaction.
Depok: Faculty of Engineering, Universitas Indonesia, 2016
UI-IJTECH 7:1 (2016)
Artikel Jurnal  Universitas Indonesia Library