Waste to Valuable by-Product: Kinetic and Thermodynamic Studies of Cd, Cu and Pb Ion Removal by Decanter Cake

Palm oil mills generate about 4 - 5 tons of decanter cake for every 100 tons of palm fresh fruit bunch processed. Due to the high organic content, the decanter cake could be converted to adsorbent for the removal of metal ions from waste water. The decanter cake was first dried at 105 oC and then carbonized at 500 oC. Earlier data showed that 500 oC had highest performance in ions removal. The resulting carbonized decanter cake were tested for removing cadmium (II), copper (II), and lead (II) ions. Proximate analysis using thermogravimetry of decanter cake carbonized at 500 oC indicated that the adsorbent contained 4% moisture, 21% volatile, 23% fixed carbon, and 52% ash. Adsorption test was carried out by mixing 1.0 g of the decanter cake in 100 mL aqueous solution of the various ions. Langmuir and Freundlich isotherm models were used to fit the isotherm experimental data. The maximum uptakes of Cd, Cu and Pb onto the carbonized decanter cake in this study were estimated to be 24, 23, and 97 mg/g respectively. The adsorption kinetics was found to follow the pseudosecond-order kinetic model. Thermodynamic parameters such as standard enthalpy (H), standard entropy (S) and standard free energy (G) were determined

ROBUST MOTION CONTROLLER DESIGN FOR PRECISE TRACKING OF BALL SCREW DRIVEN POSITIONING SYSTEM

This paper presents the design and analysis of cascade NP/PI position controller for machine tools application. The proposed control structure is an enhancement over the classical cascade P/PI position controller whereby a nonlinear function was designed and embedded onto cascade P/PI controller scheme to add element of robustness to the controller characteristics. The controller design consisted of three steps, namely; design of speed loop, design of position loop, and design of the nonlinear function. Both the speed loop and the position loop were designed based on loop shaping method in frequency domain using gain margin and phase margin as design considerations. The controller gains were confirmed based on results of stability. Three parameters identified for the nonlinear function were rate of variation of nonlinear gain (KO), maximum value of error, (emax) and sampling frequency, (δ). The controller tracking performances were numerically analysed and validated on an XY feed table positioning system. Cascade NP/PI were found to produce superior tracking performance over cascade P/PI controller with improvement in tracking performance of 6.63% and 15.63% at reference tracking frequencies of 0.4Hz and 0.7Hz respectively

EVALUATION ON TRACKING PERFORMANCE OF NPID TRIPLE HYPERBOLIC AND NPID DOUBLE HYPERBOLIC CONTROLLER BASED ON FAST FOURIER TRANSFORM (FFT) FOR MACHINE TOOLS

Accuracy and precision are the area of interest in machine tools application. It is evaluated via the measurement of tracking performance of the controllers. This study presents a Fast Fourier Transform (FFT) technique that used to evaluate the tracking performance of two controllers, namely NPID Triple Hyperbolic controller and NPID Double Hyperbolic controller for XY Table Ball-screw driven system. The cutting force characteristics are observed by using a FFT technique. Peak amplitude of FFT error on harmonic frequency was observed as a cutting force occurrence on the control system. Two cutting force disturbances that are generated from spindle speed of 1500 rpm and 2500 rpm at frequency of 0.2 Hz of speed of motor were used as a configuration set up to compare the tracking performance between the two controllers. The average error reduction of FFT error at cutting force of 1500 rpm between NPID Double Hyperbolic and NPID Triple Hyperbolic was 25.12%. This average error reduction result showed that the NPID Double Hyperbolic controller produced better tracking performance compared to the other controller. For future work, it is recommended to explore the superiority features offered in artificial intelligence tool box for better judgment in tuning control parameters

Fuzzy Analytic Hierarchy Process (FAHP) Integrations for Decision Making Purposes: A Review

Fuzzy Analytic Hierarchy Process (FAHP) is generally used as decision making purpose. However, AHP provides a single numerical number. As the method can only yield binary decisions of either “yes” or “no”, the method is not compatible when the decision has uncertainties. Consequently, previous researchers have fused AHP with fuzzy to process alternatives with uncertainty judgment. In this paper, fundamental knowledge of separate tool was reviewed. Fundamental of both fuzzy and AHP were also  summarized in this article. The next phase of this paper was to split the types of FAHP namely to determine the relative weight and the rank or score. Two methods were utilized under FAHP to determine relative weight ; triangular and trapezoidal FAHP. Next type of FAHP was to determine the score of each alternative often carried out after triangular or trapezoidal FAHP. The second types of FAHP were Fuzzy TOPSIS, and VIKOR. These FAHPs were explained and steps to carry out were presented in this paper. In conclusion, all types of FAHP are compared in terms of computational time, number of steps and level of difficulty

DEVELOPMENT OF A SIMPLE MOBILE ROBOT FOR HUMAN-ROBOT INTERACTION IN HEALTH CARE ENVIRONMENT

Human-robot interaction (HRI) field investigates how humans interact with robots. This project develops a simple robot with HRI features to solve the waiting problem of hospital patients and visitors to get attention from nurses. Interactive features of the robot include a LCD touchscreen mounted on a line-following mobile platform and a wireless remote call button. SolidWorks 2013 software was utilized to design the outlook of the HRI robot. The best conceptual design with safe and user-friendly features was fabricated. Using Proteus, the electrical circuit was simulated and the Nextion Editor created the Graphical User Interface (GUI) for the LCD display. Programming for Arduino Mega controller involved infrared sensor, DC motors, ultrasonic sensor and RF module. The completer robot has features including line following, obstacle avoidance, remote call button and carries bottled drinking water. Its LCD boost a GUI system and a cartoon game. Reliability tests were conducted to establish the robot’s viability and functionality. Usability test at the ward in UTeM Health Center showed that the patient volunteers could communicate with and able to request for services provided by the robot. This indicates that the simple robot with HRI features was able to interact with patients in real hospital environment