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Optimizing Amorphous Silica Recovery from Rice Husk Cultivated under Different Soils for Supplementary Cementitious Material Application

Hung Phan Viet, Linh Ve Quoc, Anh Vo Cong, Tien Do Thanh, Tuan Ngo Quy, Hanh Tran Duc, Phu Dao Van, Thanh Nguyen Thi, Phuong Pham Xuan, Phuc Pham Thi Thanh

Advances in Science and Technology. Research Journal

2024

Vol. 18, no 5

258--267

Amorphous silica (a-SiO₂), found in rice husk ash, is a valuable material due to its high silica content, large surface area, excellent pozzolanic properties, and strong binding ability with cement. These characteristics make it ideal for use as a supplementary cementitious material and a sustainable alternative for the partial replacement of ordinary Portland cement. This study aims to optimize the recovery process of amorphous silica from rice husks cultivated under various soil conditions (normal, drought, saline, and acidic soils), which are experiencing significant fluctuations due to climate change in many rice-producing countries. Experiments were conducted on rice husks under different pyrolysis conditions at temperatures of 700 °C, 800 °C, and 900 °C, with varying calcination durations. Through comprehensive analysis using Scanning electron microscopy (SEM) and X-ray Diffraction (XRD), along with the evaluation of amorphous silica recovery efficiency, we identified the optimal conditions for producing amorphous silica from rice husks. The analysis revealed that the highest recovery efficiency was achieved at a pyrolysis temperature of 700 °C for 1 hour. Under these conditions, the recovery efficiencies were 87.9% for normal soil RHA, 96.5% for saline soil RHA, 94.8% for drought soil RHA, and 95.6% for acidic soil RHA. The phase structure, surface morphology, and particle size of the RHA-derived amorphous silica, ground to micrometer sizes, were found to be similar to commercial products such as ordinary Portland cement and silica fume. This study provides a foundation for scaling up the production of amorphous silica from rice husk ash on an industrial scale, considering the relationship between optimal recovery efficiency and the origin of the rice husk ash, thus contributing to the development of environmentally friendly construction materials.

LQR controller design for mini motion package electro-hydraulic actuator control

Tan Nguyen Van, Tran Huy Q., Hung Phan Viet, Phu Huynh Minh

Annals of Computer Science and Information Systems

2021

Vol. 27

81--86

Electro-hydraulic actuators have been widely applied in the industry because they have several major advantages. In this paper, we focused on controlling the mini motion package electro-hydraulics actuator. First, a mathematical model of the electro-hydraulic actuator (EHA) was implemented to apply the control process to the proposed system. Second, we applied the linear quadratic regulator (LQR) controller to a linear model that is converted from the nonlinear EHA system. Finally, the numerical simulation results were performed in which the results obtained from the LQR controller were compared with the PID controller to show the superiority of the proposed solution.