Sirindhorn International Institute of Technology

About: Sirindhorn International Institute of Technology is a based out in . It is known for research contribution in the topics: Supply chain & Combustion. The organization has 1048 authors who have published 1678 publications receiving 30067 citations.

Swing Phase Control of Semi-Active Prosthetic Knee Using Neural Network Predictive Control With Particle Swarm Optimization

Abstract: In recent years, intelligent prosthetic knees have been developed that enable amputees to walk as normally as possible when compared to healthy subjects. Although semi-active prosthetic knees utilizing magnetorheological (MR) dampers offer several advantages, they lack the ability to generate active force that is required during some states of a normal gait cycle. This prevents semi-active knees from achieving the same level of performance as active devices. In this work, a new control algorithm for a semi-active prosthetic knee during the swing phase is proposed to reduce this gap. The controller uses neural network predictive control and particle swarm optimization to calculate suitable command signals. Simulation results using a double pendulum model show that the generated knee trajectory of the proposed controller is more similar to the normal gait than previous open-loop controllers at various ambulation speeds. Moreover, the investigation shows that the algorithm can be calculated in real time by an embedded system, allowing for easy implementation on real prosthetic knees.

Bio-electrochemical system for recovery of silver coupled with power generation and wastewater treatment from silver(I) diammine complex

Abstract: In this study, a bio-electrochemical system was used to investigate the recovery of silver from diammine complex [Ag(NH3)2]+, coupled with power generation and wastewater treatment, measured in terms of chemical oxygen demand (COD) removal. Acetate was oxidized by anodic microorganisms to produce electrons, which were transported to the cathode for the reduction of [Ag(NH3)2]+ complex. After 48 h of operation at different initial [Ag(NH3)2]+ concentrations (1000–3000 mg Ag/L), a Ag removal of over 96%, along with a COD removal of 60–76.80%, and a columbic efficiency of 8.55–14.69%, were achieved. Maximum power density slightly increased by 4.66%, from 3618 to 3795 mW/m3, when 10 mM NaNO3 was added to the catholyte containing 2000 mg Ag/L. The diffusion of [Ag(NH3)2]+ ions through the membrane affected the performance, as the inorganic fouling at the membrane surface increased the internal resistance. This transport was confirmed by the accumulation of silver in anodic biomass (0.853 mg Ag/g biomass) after 58 days. Scanning electron microscope (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) analysis demonstrated Ag deposits with a dendritic structure formed at the cathode surface. A deeper understanding on bio-electrochemical technology used for Ag recovery and electricity production from [Ag(NH3)2]+ complex was achieved in this study.

Crystallization of Polylactide and Its Stereocomplex Investigated by Two-Dimensional Fourier Transform Infrared Correlation Spectroscopy Employing Carbonyl Overtones

Abstract: The band origins and transitions of weak vibrational modes developed in the 3500 cm−1 region of polylactide (PLA) spectra during crystallization are investigated. The band assignment to the OH stretching mode of terminal hydroxyls is unlikely because the trace amount of chain-ends is negligible considering the long chain of high molecular weight polymer. The band intensity can be enhanced for quantitative study by increasing the sample film thickness. The results show that the transition patterns of these bands mimic those of C=O stretching modes. Therefore, these are assigned to CXO overtones. Two bands associated with crystalline and amorphous characteristics are revealed during cold crystallization. The crystalline C=O bands of PDLA and its stereocomplex counterpart are located at 3510 cm−1 and 3482 cm−1, respectively, indicating a weaker C=O bond in the latter crystal structure. Two-dimensional Fourier transform infrared (2D-FT-IR) correlation spectroscopy is then applied to study the correlation betw...