Papers by Keyword: Optimization

Abstract: In this study, performance of polyacrylamide grafted cellulose flocculant derived from Pandan leaves to treat reactive black 5 (RB5) dye from aqueous solution were investigated. Response surface methodology (RSM) and Box-Behnken design (BBD) of experiment were employed to identify the optimum condition for chemical oxygen demand (COD) reduction in RB5 dye. The optimization was based on three operating variables; initial dye concentration, flocculant dosage and pH. The optimum condition for COD reduction was achieved at initial dye concentration of 0.03 g/l with flocculant dosage of 0.06 g, at pH 11.72. Under this condition, the reduction of COD was achieved up to 54.24%. Linear and quadratic effects of flocculant dosage and pH are the most significant in affecting the degree of flocculation efficiency. The coefficient of determination (R²) of 81.77% for percentage reduction of COD level confirms that the models used in predicting the degree of flocculation efficiency has a very good agreement with the experimental results.

Abstract: The transesterification of waste vegetable oil (WVO) with methanol in the presence of potassium hydroxide (KOH) is studied in order to produce biodiesel. All the results were evaluated using central composite design by applying a double 5 level 3 factor full factorial designs. Twenty experiments were replicated under the typical range of parameter conditions coded as x₁ for oil molar ratio, x₂ as catalyst concentration and x₃ for reaction time. The experimental fatty acid methyl ester (FAME) are compared with the predicted FAME using RSM. The optimal predicted FAME production was obtained at 92.60%. It is specified under conditions of molar ratio 4:1 mol/mol, 0.5033 wt% catalyst concentration and reaction time of 60 minutes.

Abstract: With the rapid development of economic, energy shortages have become increasingly prominent. Developing the new clean energy, wind energy, has become an inevitable trend. In this paper, different fan foundation schemes are proposed and compared, and it shows that the total investment of the single pile foundation is higher than that of high pile caps foundation and the scheme of high pile caps foundation with 3.0 MW can be used as the optimal solution to guide the project investment.

Abstract: We describe a procedure for the optimization of a 3C-SiC buffer layer for the deposition of 3C-SiC on (001) Si substrates. A 100 – 150 nm thick SiC buffer was deposited after a standard carbonization at 1125 °C, while increasing the temperature from 1125 °C to 1380 °C. Ramp time influenced the quality and the crystallinity of the buffer layer and the presence of voids at the SiC/Si interface. After the optimization of the buffer, to demonstrate its effectiveness, a high-quality 3C-SiC was grown, with excellent surface morphology, crystallinity and low stress.

Abstract: An experimental study of GTAW was conducted to determine the optimization of weld parameters on the droplet formation in the surface quality of weld pools. These optimization investigations consisted of welding current, welding speed and feed rate. The strength and surface quality of weld pool were measured for each specimen after the welding parameter optimizations and the effect of these parameters on droplet formation were researched. To consider these quality characteristics together in the selection of welding parameters, the Orthogonal Array of Taguchi method is adopted to analyze the effect of each welding parameter on the weld pool quality, and then to determine the welding parameters with the optimal weld pool quality.

Abstract: Based on the current design of actuator for soft-close automatic car doors, function and composition of the mechanical assembly and the electronic control module of the actuator are elaborated firstly. Then the push travel section of cam profile is optimized from previous circular arcs to a spline curve to reduce impact and fatigue wear between the switch and the cam in the mechanical assembly through multi-body dynamics simulation with the Adams solving tool in NX7.5. Besides, an improvement of the MOSFET bridge drive circuit and corresponding program design through dead-time control method with half-bridge chopper are applied to solve the heating problem in the electronic control module, in the light of equivalent electronic circuit simulation in Multisim. The results demonstrate that the optimization works well, and valuable conclusions can be drawn from system simulation during the prototype stage of the actuator product is practicable.

Abstract: Effective control of an elastic space vehicle is possible only on the basis of exact information on its elastic oscillations. Exact estimation of these oscillations is possible via a distributed system of measuring instruments installed in different points of the elastic design. In recent years, new types of inertial measuring devices came into use like micro-electro-mechanical (MEMS) gyroscopes and accelerometers. Significant progress in the development of on-board computers allows the use of modern means of filtering algorithms, based on numerical integration of a large number of differential equations in real time. Miniaturization of sensors and the decrease of their power consumption increases admissible quantity of used sensitive elements and reduces restrictions for their placement. This article presents new results on optimization of placement of system of sensors on an elastic controlled object.

Abstract: Through the analysis of the feasibility of using network technology and network technology in supply chain management system, the paper puts forward the design framework of supply chain management system based on the Internet of things, describes the key technology of the system. The application of Internet of things in the supply chain management system, that will realize the effective management of the whole supply chain; enhance the competitiveness of enterprises and the whole supply chain.

Abstract: For the lack of specific constrains, the lack of multi-sectoral joint supervision and the lack of data acquisition for online overseas purchasing and irregular clearance procedures and the loss of national revenue during the process of online overseas purchasing, this paper analyzes and restructures the process of it based on iDEF0 and IDEF3 models. Advantages of the restructuring process are mentioned in this paper.

Abstract: This work try to optimize the flow field and concentration field of SCR system. Firstly, the original SCR system is simulated by Fluent and two kinds of guide plates are utilized. The simulation results show that the straight guide plate is slightly better than curve guide plate. The relatively standard deviation of velocity and concentration fields and pressure drop agree with the design rules. To verify the simulation results, a 1:10 scale cold plexiglass test plant is established and this plant is simulated correspondingly. The simulation results are in good agreement with experimental results. So the simulation results of original SCR system are credibly and can guide the practical engineering.