Papers by Keyword: Response Surface Method (RSM)

Abstract: The objective of this study is to reduce a number of defects in Hard Disk Drive (HDD) manufacturing due to spiral scratch on media by applying DMAIC steps of Six Sigma approach. The spiral scratch is firstly identified as the significant loss with 6.03% defective rate. Secondly, the paddle to disk space, top cover edge sharpness, pitch static attribute and number of load/unload cycle are found to be the key process input variables (KPIV). The experiment based on four KPIVs is then designed following Box Behnken design. With the results from the experiment, the response surface method is applied to determine the optimal setting for these four KPIVs with respect to the minimum percentage of the spiral scratch. Finally, the process with the optimal settings of the paddle to disk space at 3 mm, top cover edge sharpness at 0.002 inch, pitch static attitude at 0.01 inch and number of load/unload cycle at 10,000 times is implemented and monitored by the p control chart. After the improvement, the defective rate of the spiral scratch is decreased by 48.8% from 6.03% to 3.09%.

Abstract: With the conversion efficiency of tung oil methyl esterification as judgement index, univariate analysis for three main influencing factors, dosage of KOH and methanol, reaction time, were studied and optimized with response surface method to build a model in the one step methyl esterification of tung oil. Test and verify of this model were completed. The result showed that when dosage of KOH and methanol, time corresponded to 0.80g, 54.80g and 60min, the efficiency of tung oil methyl esterification was 94.52%. This result was only 4.72% lower than the predicted value from the model, which meant that the model was reliable to predict actual process. The efficiency of tung oil methyl esterification under two step process was 95.12%. There was little difference with one step process. But the total material cost of the optimized one step process was 1.76% less than that of the optimized two step process, and the reaction time was only need 1/4 that of two process. At the same time, operating process of one step was more simple and convenient. So, one step process for tung oil methyl esterification may be more cost-effective in industrial production.

Abstract: The single-factorial design of experiments and response surface methodology was applied to optimize ultrasonic-assisted regeneration of coconut shell activated carbon. With the pH values of the solution, solid-liquid ratio, irradiation time chosen as the independent variable and the activated carbon release of antimony as response values, the central composite design method was used to study each of the variables and their interactions on coconut shell activated carbon regeneration. The results of this study showed that: the optimum pH value was 13; solid-liquid ratio was 372 mL·g^-1; irradiation time was 6.7 h. The average content of the release of Sb from the activated carbon was 6233.95 μg·g^-1 under the optimum condition. Regeneration rate of the activated carbon was 84.45%. This demonstrated that the adsorption efficiency of Sb was close in regenerative carbon and the original carbon. The results proved that the ultrasonic-associated coconut shell activated carbon regeneration process was accurate and reliable, and can provide a reference for the regeneration of coconut shell activated carbon which had adsorbed Sb.

Abstract: In this study, our objective was to prepare levalbuterol hydrochloride drug-resin and investigate its characteristics. This work is basis for the study of the next levalbuterol hydrochloride sustained-release suspensions. The drug-resin was prepared by bath method. The effect of factors , including resin types, drug concentration, speed, temperatures and pH on evaluation index, was evaluate by Drug utilization rate and the resin loading. Then the Box-Behnken Design-response surface method was used to optimize the preparation. The drug content determined by UV method and drug-resin were characterize by IR and DSC．The best formulation of levalbuterol hydrochloride drug-resin was used the bath method IRP69 resin at 30°C. The drug concentration was 1.8 mg•ml^-1, and the rotate speed was 250 rpm, the pH was 5.8. The preparation of levalbuterol hydrochloride drug-resin method is simple and feasible, and the drug combined with the resin by the chemisorption of ionic bond.

Abstract: Investigations were carried out to optimize ultrasonic-assisted preparation of liposome-encapsulated paprika red. The effect of process variables namely the ratio of soybean lecithin to paprika red, solvent volume, cholesterol content and sonication time was evaluated using single-factor test and response surface method (RSM). The liposomes showed significant effect on the improvement of light irradiation stability of paprika red, and the stability was greatly improved when antioxidants such as tert-butyl hydroquinone (TBHQ) or dl-α-tocopherol were introduced. The optimal ingredient for liposome-incorporated paprika red was 0.1% dl-α-tocopherol supplemented, in which 32.3% paprika red remained from degradation after light irradiation for 9 h with the intensity of 4000 lux, comparing with 0% that of the control.

Abstract: To optimum the chelation technology of whey protein hydrolysate with calcium, the response surface method was used to investigate optimized technological conditions. The result showed that the optimum process parameters for the whey protein hydrolysate-calcium chelation were whey protein peptide and CaCl₂ ratio of 24 : 1 (w/w), whey protein hydrolysate concentration 3.5 %, pH 7.5, reaction time 20 min, reaction temperature 30 °C. Finally, the optimum level was established and whey protein hydrolysate-calcium chelate was obtained, which can provide basic theories for the following function and activity evaluation of this potential calcium supplement.

Abstract: Technology of Friction Stir Welding (FSW) as a technique for joining metal is relatively new. In some cases on Aluminum joining, FSW gives better results compared with the Arc Welding processes, including the quality of welds and less distortion. FSW can even use milling machine or drilling machine, by replacing the tools and the appropriate accessories. The purpose of this study is to analyze the effect of process parameters on micro Friction Stir Lap Welding to the tensile load of welds. In this case, Aluminum material A1100, with thickness of 0.4 mm was used. Tool material of HSS material was shaped with micro grinding process. Tool shoulder diameter was 3 mm, while the diameter pin was 2 mm and a length of pin was 0.7 mm. The parameter variations used in this study were the variable of spindle speed (2300, 2600, and 2900 rpm), variable of tool tilt angle (0, 1, 2 degree) and a variable of Feed rate (50, 60, 70 mm/min). Where the variation of these parameters will affect to the mechanical properties of welds (as response) was the tensile load. Analysis and optimization parameters between the micro FSLW parameters with the tensile load of welds, is used a Response Surface Methods (RSM). From the result of experiment and analysis, it is shown that the important welding parameter in Micro Friction Stir Lap welding process is tilt angle.

Abstract: It is the aim of this research to describe the horizontal well performance in different conditions, this paper firstly introduces 13 dimensionless variables to describe the influence factors of horizontal well performance in bottom water reservoir and calculates the range of all the variations from low to high level by making a statistics of the actual field data of the 23 horizontal wells, then establishes the oil recovery model with response surface method using a 3 level-13 variables Box-Behnken design (BBD) . Based on the evaluation model, single factor sensitivity and interaction analysis between any two factors are carried out. Finally, research on horizontal well in typical bottom water reservoirs indicates that the values calculated by the new evaluation model fit the actual field data, which proves that the evaluation model can provide criteria for the design or optimization of horizontal well development in a bottom water reservoir.

Abstract: Rear sub-frame is one of the important parts of automobile chassis. Tube hydroforming (THF) is a kind of the advanced manufacturing technology to produce the sub-frame. The success of a THF process is highly dependent on the loading paths (axial feed versus pressure) used. The uniform design method combined with the response surface method was used to optimize the loading path in this paper. The results obtained by numerical simulation demonstrated that product quality is good in the optimized loading path.

Abstract: This paper studied the suspension characteristics of ginkgo, and designed a cleaning machine of ginkgo as well. At the same time, the effects of feeding speed, the wind speed and the angle of wind outlet on the performance of the equipment were analyzed, and a mathematical model was established. By taking multi-objective optimization method and response surface method, this paper obtained the conclusion that the best combination conditions of cleaning equipment of ginkgo: the feeding speed was 270.86kg/h, the wind speed was 9.25m/s, and the angle of wind outlet was 17°. Then the cleaning equipment reached the best performance: the loss rate was 1.20%, while the cleaning rate was 95.21%.