An improved ashing procedure for the determination of heavy metals in edible oils

An accurate, reliable, and simple method was described for the determination of Pb, Cu, Cd, Mn, Zn, an d Fe in edible oils by atomic absorption spectrophotometry following burning of the sample in a restricted air supply. Recoveries for the six heavy metals by the proposed methods were about 100%. The relative standard deviation of the analysis for the lead at the level of 0.074 ppm was 6%, and the copper at the levels of 0.064 ppm and 0.158 ppm were 7% and 2%, respectively. The recovery of lead was found to be suppressed by the presence of a large quantity of iron in the oil, but the suppression was alleviated by adding a Mg(NO₃)₂ solution to the charred residue before ashing.     

Dilute solution properties of cationic poly(dimethyl sulfate quaternized dimethylaminoethyl methacrylate)

The dilute solution properties of a cationic polyelectrolyte, poly(dimethyl sulfate quaternized dimethylaminoethyl methacrylate) [poly(DMAEM · C₂H₆SO₄)], are studied by measurements of intrinsic viscosity, degree of binding, and flocculation application. The intrinsic viscosity of this polyelectrolyte is related to the type and concentration of added salt. The intrinsic viscosity behavior for cationic polyelectrolyte resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. The polyelectrolyte in the presence of KCl has a lower degree of binding, indicating that the proton ion (H⁺) is relatively difficult to bind to the CH₃SO₄^? at the polymer end. The polymerization of DMAEM · C₂H₆SO₄ in 0.5M KCl aqueous solution proceeded more easily than that of DMAEM · C₂H₆SO₄ in pure water. The polymerization rate of DMAEM · C₂H₆SO₄ is found to pass through an extreme value as a function of pH. Optimum flocculation, corresponding to the complete removal of turbidity in the supernatant, is achieved. Beyond the optimum flocculation, high polymer dosages redisperse the bentonite suspensions.     

Delamination Effect on Flutter of Homogeneous Laminated Plates

The effect of delamination on the flutter boundary of two‐dimensional laminated plates are investigated theoretically. Linear‐plate theory and qusai‐steady aerodynamic theory are employed. A simple beam‐plate‐theory model is developed to predict the flutter boundaries of delaminated homogeneous plates with simply supported ends. The effects of delamination position, size, and thickness on the flutter boundary are studied in detail. The results reveal that the presence of a delamination degraded the stiffness and the natural frequencies of the plate and thereby decreases the flutter boundary of the plate. However, for certain geometries the flutter boundaries were raised due to the flutter coalescence modes of the plate altered by the presence of a delamination in the plate.     

Controlling a robot's position using neural networks

In order to fully utilise the power of robots in factories, robot process capability (RPC) must be considered and improved. To improve the RPC in on-line processing by applying robot learning, the counterpropagation network was modified in this research. With two layers, the counterpropagation network was modified to control a robot's gross and fine motions. For the first layer, the network serves as a sensor-signal generator to control the gross motion. For the second layer, the network serves as a fine motion adjuster. Also, each layer can be separated functionally. By controlling both the gross and the fine motions, the RPC can then be improved. The modified two-layer counterpropagation network control scheme was validated by computer simulation and physical implementation on a RS-2200 robot system.     

Factors affecting online group buying intention and satisfaction: A social exchange theory perspective

This study investigates factors that affect consumer continuous use intention toward online group buying and the degree that reciprocity and reputation of social exchange, trust, and vendor creativity affect consumer satisfaction and intention toward online purchasing. Data from 215 valid samples was obtained using an online survey. The research model is assessed using partial least squares (PLS) analysis. The results show that the intention to engage in online group buying is predicted collectively by consumer satisfaction, trust, and seller creativity. Consumer satisfaction with online group buying is predicted primarily by trust, followed by consumer reciprocity. The proposed research model explains 67.7% of variance for satisfaction and 39.7% of variance for intention to engage in online group buying. The results suggest that reciprocity, trust, satisfaction, and seller creativity provide considerable explanatory power for intention to engage in online group buying behavior.     

Design of a non-inverting synchronous buck-boost DC/DC power converter with moderate power level

This paper presents the design of a non-inverting synchronous buck-boost DC/DC power converter with moderate power level for a solar power management system. The buck-boost requirement arises from the rapid changes in the atmospheric condition or the sunlight incident angle. The system mainly consists of the non-inverting synchronous buck-boost DC/DC power converter, MOSFET drivers, anti-cross conduction logic circuitry, feedback compensator, and PWM regulator. The system is capable of converting the supply voltage source to higher and lower voltages to the load terminal with voltage polarity unchanged. The voltage at the load terminal is controlled by continuously adjusting the duty cycle of the PWM regulator. Application of the buck-boost converter in battery management system design is also addressed.     

Path planning of a multiple mobile robot system

We present path-planning techniques for a multiple mobile robot system. The mobile robot has the shape of a cylinder, and its diameter, height, and weight are 8 cm, 15 cm, and 1.5 kg, respectively. The controller of the mobile robot is an MCS-51 chip, and it acquires detection signals from sensors through I/O pins. It receives commands from the supervising computer via a wireless RF interface, and transmits the status of the robots to the supervising computer via a wireless RF interface. The mobile robot system is a module-based system, and contains a controller module (including two DC motors and drivers), an obstacle detection module, a voice module, a wireless RF module, an encoder module, and a compass detection module. We propose an evaluation method to arrange the position of the multiple mobile robot system, and develop a path-planning interface on the supervising computer. In the experimental results, the mobile robots were able to receive commands from the supervising computer, and to move their next positions according to the proposed method.