Papers by Keyword: Experimental Design

Abstract: Dysprosium oxide nanoparticles (Dy₂O₃-nanoparticles) have been extensively used in many different fields of technologies. In addition, with a proper synthesis modification, Dy₂O₃-nanoparticles are promising materials not only for industry purposes, but also for biomedical applications, for instance, through polyethyleneglycol (PEG) attachment as a template on nanoparticles. This study focuses on the optimization of hydrothermal synthesis of Dy₂O₃-nanoparticles using Response Surface Methodology – Box-Behnken experimental design (RSM-BBD). The influences of the volume and concentration of PEG-template to the size diameter of nanoparticles were also studied. The crystal structure and surface morphology Dy₂O₃-nanoparticles with PEG-template modification were characterized using Tabletop Scanning Electron Microscopy (TSEM) coupled with Energy Dispersive X-Rays (SEM-EDX) and X-Rays Diffraction (XRD). Dy₂O₃-nanoparticles were prepared by using hydrothermal synthesis method with PEG-template attachment on the nanoparticles. PEG as a template will create the uniform shapes and prevent the agglomeration of the nanoparticles. For further biomedical applications, it also helps to enhance the biocompatibility of nanoparticles. The optimization of influence parameters on the hydrothermal synthesis of Dy₂O₃-nanoparticles, (e.g. mass ratio precursor (PEG and Dy₂O₃), temperature, and time) were investigated using RSM-BBD. The optimum conditions were 15 g PEG and 0.45 g Dy₂O₃ at 200°C for 7 h resulting in the highest amount of Dy₂O₃-nanoparticles products. SEM image results show spherical and nanowires shapes of Dy₂O₃-nanoparticles produced with the average size diameter of 10.1 nm as the smallest size of nanoparticles. In addition, XRD-patterns indicates the typical cubic structure of Dy₂O₃-nanoparticles with the estimation crystal size of 45.47 nm.

Abstract: This study aimed to prepare diclofenac sodium (DCF)–loaded nanostructured lipid carriers (NLCs) (DCF-loaded NLCs) for optimizing the NLCs by using the Box-Behnken design. A hot emulsification method using an ultrasonic probe was employed to prepare DCF-loaded NLCs. The active ingredient, solid lipid, oil, and emulsifier were DCF, glyceryl monostearate (GMS) (X₁), oleic acid (X₂), and polysorbate 80 (X₃), respectively. The DCF-loaded NLCs had particle sizes of 69.29–187.3 nm. The polydispersity index (PDI) was in the range of 0.216–0.516, indicating a relatively narrow size distribution. The zeta potential of all formulations revealed the negative charge and ranged between -26.0 and -42.13 mV. The percentage encapsulation efficiency (%EE) was 92.71%–104.21%. The responses of all model formulations were created and the optimized formulation was selected by Design-Expert® software. The optimal formulation was composed of 2 g GMS, 0.926 g oleic acid, and 2.724 g polysorbate 80. The particle size and PDI experimental values with the optimal formulation did not differ from those predicted and were within the 95% CI. Therefore, the Box-Behnken design could be efficient in formulating and optimizing DCF-loaded NLCs.

Abstract: The results of the studies on the creation of self-compacting fine-grained fiber-reinforced concrete based on run-of-crusher stone with the use of a polyfunctional additive D-5 are presented. Compositions of self-compacting fine-grained fiber-reinforced concrete with the use of basalt fiber have been developed, which significantly reduce cement consumption and improve the characteristics of fine-grained concrete mixture and concrete. Using a polyfunctional additive D-5in mixtures makes it possible to increase the strength properties of fine-grained fiber-reinforced concrete while improving the concrete mixtures’ rheological characteristics. Replacement of cement up to 10% of the mass by ash fraction d<0.14 min fine-grained concrete mixtures does not cause a noticeable decrease in the concrete strength properties. The developed self-compacting fine-grained fiber-reinforced concretes have increased strength properties and have a low-cost price due to the use of local raw materials and run-of-crusher stone.

Abstract: The foam-mat dryingprocessof egg white, developed in the food industry, promotes a porous product, brittle and easy to grind. The powderedegg white has a good rehydration properties, safer consumption and storage conditions than fresh product, keeping the high level of proteins and vitamins contained in the egg. In this way, the objective of this work is to study, through numerical computational simulation, the physical aspects of the duck egg white foam-matdrying process. For this, the foam was characterized by its density, percentage of expansion, air over run, stability and moisture. Temperature (50, 60 and 70°C), stirring rate (levels 6, 7 and 8) and stirring time (4, 5 and 6 minutes) are taken as input conditions and the product final moisture and drying time are the output variables. Drying was performed based on the complete factorial 23 + 3 central point experimental design in this procedure. It has been observed that the time and stirring rate significantly influence the product final moisture and that the drying temperature is predominant for the total process time. From the foam moisturedata, adjustments of empirical mathematical models were made; evidencing that theModifiedPage and the Page models provided the best results, with a standard deviation lower than 0.01 and the coefficient of determination above 0.99. For this analysis, the case where the drying temperature, time and the stirring rate were, respectively, 70 °C, 6 minutes and 8 level, presented the best results.

Abstract: In this study, Nylon 6 (PA6) was reinforced with glass fibers and molded using different injection parameters. The PA6 samples were then subjected to fatigue tests, and the results were processed to study (i) how the glass fibers affected the PA6 fatigue displacement and (ii) which injection parameters influenced the PA6 fatigue property. To do so, single-factor experimental designs were implemented in which the control factors were the glass-fiber percentage, the melt temperature, the hold pressure, the hold time, the injection pressure, and the injection time. Correlational analyses were used to predict the relationships between the control factors and fatigue results. A two-factor design was then applied to determine the two factors that influenced the PA6 fatigue displacement the most, with analysis of variance being used to determine how the factors affected the fatigue property. In this study of injection plastic, the glass-fiber percentage of PA6 composite was found to be the main factor that affected the fatigue displacement the most.

Abstract: . An understanding of the dynamic characteristics of a CNC machine is a vital element in the control of the machine which has a direct effect on the machining precision. The ways in which energy is dissipated, such as friction and damping, have a significant effect on the dynamic behavior and spindle vibration of a CNC machine. The paper presents kinetic analysis of the CNC machine damper system, effect of the damper and the cutting parameters such as feed rate, cutting speed, and cutting depth on the dynamic behavior and spindle vibration of a CNC machine. Experimental results have established a second-order regression equation that demonstrates the effect of three parameters such as feed rate, cutting speed, and cutting depth on the vibration amplitude of the spindle. In addition, the comparison results show that the spindle head vibration amplitude of the machine using the damper is smaller than the spindle head vibration amplitude of the machine not using the damper.

Abstract: Due to the awareness of adverse effects of conventional fuels to environment and the frequent rise in crude oil price, the need for sustainable and environmentally friendly alternative source of energy has gained importance in recent years. This alternative has been identified to be biofuel, one of which is biodiesel. As such, this work was carried out to contribute to the development of biodiesel. The aim was accomplished by employing Design Expert, based on the chosen operating factors (reaction temperature and methanol-to-oil ratio), to design experiments carried out for the production of biodiesel using used cooking oil and methanol in the presence of alkaline catalyst. After carrying out the experiments using the design parameters generated, the results were analysed, and a model equation was developed for the system. Furthermore, the model equation was used to optimize the process using Excel Solver to obtain a temperature, a methanol-to-oil ratio and a yield of 63.45 °C, 3 and 59.32 as the optimum values, respectively. The optimum parameters estimated were validated experimentally and with the Aspen HYSYS model of the process that was also developed. The results obtained using the design factors showed that the factors considered were having effects on the yield of biodiesel. Also, the results of the experimental validation carried out with the optimum parameters obtained with the aid of Excel Solver were found to compare very well with those obtained from the simulation of the developed Aspen HYSYS model of the biodiesel production because the errors were estimated to be less than 5%. Therefore, the developed Aspen HYSYS model of biodiesel production of this work was able to represent the process very well and can be used for further studies on the process.

Abstract: A design of experiments based on the Taguchi method was used to evaluate the main parameters affecting the removal of textile dyes from aqueous solution. By using the adsorption capacity of textile dye as target response, several experiments were carried out using L₂₇ orthogonal array, and the higher-the-better as quality characteristics was applied. The controlling factors, including initial dye concentration, contact time and pH of solution were assessed. Analysis of variance (ANOVA) was used to determine the effects of each factor on the adsorption capacity. The optimum adsorption conditions giving higher adsorption capacity were selected as initial dye concentration of 500 mg.L^-1, contact time of 180 min and pH of solution of 2. The analysis results revealed that the most relevant factors affecting the adsorption process of textile dye are the initial dye concentration and pH of solution. After 3 cycles of thermal regeneration, the diatomite behavior did not change and more than 60 % of dye was eliminated from solution after regeneration at 600°C. From the obtained results, the Taguchi method was very successful to optimize of the adsorption parameters for maximum removal rate, and gives more credibility for industrial application.

Abstract: The strength development of a quaternary Portland cement composite system containing blast-furnace slag, zeolitic tuff and limestone powder is presented. The composition and particle size distribution of the constituents are optimized by the incremental coefficient of the surface activity of the zeolite-containing Portland composite cements. Zeolitic tuff and limestone powder of high specific surface area lead to the increase of the surface activity of the entire system and a corresponding improvement in the performance of the cement.

Abstract: One of the advance adhesion methods is a friction bonding process which two or more materials are welded by a combination of heat and force to soften and attain an atomic adhesion between the two work layers. Using the insufficient heat and force, it can result in a delamination, which their layers do not completely sealed after the process. On the other hand, too much heat and force can result in an overflow of inserted aluminum and weak adhesive strength. This paper aims at revealing the effect of work temperature and force on the delamination defect. A blank stainless steel 430 with a dimension of 145 mm and 0.5 mm thickness is bonded with an Al 3003. The dimension of Al 3003 blank is 255 mm in diameter and 0.5 mm thickness. An aluminum 1100 with a diameter of 130 mm and 2.5 mm thickness is used as an adhesive bonding material between the stainless steel and the Al 3003 blank. The results showed that a reduction in defect rate can be obtained by increasing the work temperature as well as the stamping force. In addition, the optimal condition of the study case is also obtained through the experimental design. It can be concluded from the analysis that at voltage of 580 Volt which is equivalent to 470 C and force of 1,000 Tons is the optimal condition providing the least defect rate. The regression model was also developed to show the relationship of factors to the delamination size. This equation can be used to predict the mentioned delamination rate at various conditions.