Optimization of Factors Influencing the Aspect Ratio of Mullite Whiskers Based on Single Factor Analysis and Response Surface Methodology

2012 ◽  
Vol 581-582 ◽  
pp. 782-785
Author(s):  
Bin Meng ◽  
Jin Hui Peng

The mullite whiskers were synthesized from commercial raw materials by sintering in air. Three factors influencing the aspect ratio of whiskers, including sintering temperature, holding time and addition amount of V2O5, were analyzed based on single factor design and response surface methodology respectively. The optimum conditions for the synthesis of mullite whiskers with highest aspect ratio was obtained, i.e. sintering temperature was 1316.87°C, addition amount of V2O5 was 4.09wt.% and holding time was 1.96h. The experiment at the optimum condition was conducted and the real experimental value agrees to the predicted value based on response surface methodology.

2012 ◽  
Vol 581-582 ◽  
pp. 819-822 ◽  
Author(s):  
Bin Meng ◽  
Jin Hui Peng

The corundum-mullite was toughened by in-situ synthesized mullite whiskers and the process parameters influencing the fracture toughness of corundum-mullite, such as sintering temperature, addition amount of AlF3 and V2O5, were optimized by means of response surface method. Corundum-mullite with fracture toughness of 9.44 MPa.m-1/2 could be obtained under the optimized conditions, i.e. sintering temperature of 1400°C, 4.8 wt.% of AlF3 and 5.8 wt.% of V2O5. The results showed that it was feasible to prepare corundum-mullite toughened by in-situ synthesized mullite whiskers by the optimized parameters. In addition, an accurate model based on response surface method was proposed to predict the experimental results.


2021 ◽  
Vol 13 (12) ◽  
pp. 6739
Author(s):  
Darko Landek ◽  
Lidija Ćurković ◽  
Ivana Gabelica ◽  
Mihone Kerolli Mustafa ◽  
Irena Žmak

In this work, alumina (Al2O3) ceramics were prepared using an environmentally friendly slip casting method. To this end, highly concentrated (70 wt.%) aqueous suspensions of alumina (Al2O3) were prepared with different amounts of the ammonium salt of a polycarboxylic acid, Dolapix CE 64, as an electrosteric dispersant. The stability of highly concentrated Al2O3 aqueous suspensions was monitored by viscosity measurements. Green bodies (ceramics before sintering) were obtained by pouring the stable Al2O3 aqueous suspensions into dry porous plaster molds. The obtained Al2O3 ceramic green bodies were sintered in the electric furnace. Analysis of the effect of three sintering parameters (sintering temperature, heating rate and holding time) on the density of alumina ceramics was performed using the response surface methodology (RSM), based on experimental data obtained according to Box–Behnken experimental design, using the software Design-Expert. From the statistical analysis, linear and nonlinear models with added first-order interaction were developed for prediction and optimization of density-dependent variables: sintering temperature, heating rate and holding time.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1741
Author(s):  
Xin Sun ◽  
Jialing Vivien Chua ◽  
Quynh Anh Le ◽  
Francisco Trujillo ◽  
Mi-Hwa Oh ◽  
...  

The response surface methodology (RSM) and central composite design (CCD) technique were used to optimize the three key process parameters (i.e., pressure, temperature and holding time) of the high-hydrostatic-pressure (HHP) processing either standalone or combined with moderate thermal processing to modulate molecular structures of β-lactoglobulin (β-Lg) and α-lactalbumin (α-La) with reduced human IgE-reactivity. The RSM model derived for HHP-induced molecular changes of β-Lg determined immunochemically showed that temperature (temp), pressure (p2) and the interaction between temperature and time (t) had statistically significant effects (p < 0.05). The optimal condition defined as minimum (β-Lg specific) IgG-binding derived from the model was 505 MPa at 56 °C with a holding time of 102 min (R2 of 0.81 and p-value of 0.01). The validation carried at the optimal condition and its surrounding region showed that the model to be underestimating the β-Lg structure modification. The molecular change of β-Lg was directly correlated with HHP-induced dimerization in this study, which followed a quadratic equation. The β-Lg dimers also resulted in the undetectable human IgE-binding.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Yingpeng Tong ◽  
Yu Jiang ◽  
Dan Guo ◽  
Yongqiu Yan ◽  
Shiping Jiang ◽  
...  

Saffron, which has many kinds of biological activities, has been widely used in medicine, cosmetics, food, and other fields of health promotion industries. Crocins are the main component of saffron (Crocus sativus L.). At present, most of the extraction methods for crocins require long time or special instruments to complete the process and some of them are not suitable for industrial production at present. In this article, homogenate extraction technology which is a convenient and efficient method was developed for crocins extraction from saffron. Firstly, the influences of extraction voltage, extraction time, ethanol concentration, and temperature on crocins yield were studied by single factor experiments; and then response surface methodology (RSM) was used to optimize levels of four variables based on the result of single factor experiments. Results showed that the optimum extraction process conditions for crocins were as follows: extraction voltage, 110 V; ethanol concentration, 70%; extraction temperature, 57°C; and extraction time, 40 s. Based on these conditions, the extraction yield of crocins can reach 22.76% which is higher than ultrasonic extraction method. Therefore, homogenate extraction is an effective way to extract crocins from saffron with higher extraction yield and shorter extraction time.


2012 ◽  
Vol 622-623 ◽  
pp. 162-165
Author(s):  
Da Wei Yin ◽  
Gang Tao Liang ◽  
Xiao Ming Sun ◽  
Yu Ting Liu

Acetylferrocene was synthesized by acetyl chloride and ferrocene as raw materials, dichloromethane as the solvent, and ZnO as catalyst. Response surface methodology based on three-level, three-variable central composite rotable design was used to evaluate the interactive effects of the ratio of acetyl chloride and ferrocene(2-4), the amount of ZnO(1.0-1.3mol), reaction time(30-60 min)on the percentage yield of acylferrocene. The optimal raw material ratio, amount catalyst, and reaction time was 3:1, 1.19mol, 40min. Under the optimum conditions, the actual experimental yield can reach 86.72%.


2019 ◽  
Vol 814 ◽  
pp. 413-418
Author(s):  
Fang Wang ◽  
Ming Han Xu ◽  
Rui Hua Wang ◽  
Chao Yang ◽  
Ai Xia Chen ◽  
...  

The construction industry continues to develop and the requirements for cement performance are getting higher and higher. At the same time, in the steel industry, the discharge of steel slag is also increasing. The effective reuse of steel slag has become a prominent problem in the steel industry. . Therefore, it is envisaged to use steel slag as a raw material for the cement production process to produce cement and to produce high-performance cement. The main raw materials of this experiment are steel slag, limestone, sandstone and shale. Through the cement preparation process, the cement is made, and then the cement is made into concrete to test its performance. This experiment mainly studies the sintering temperature and holding time variable. In the experimental test, the analysis and comparison were carried out in five aspects of the degree of macroscopic cracking, particle size, density, microstructure and composition. In the comparison experiment of sintering temperature, with the increase of temperature, the flexural and compressive properties of cement gradually increased. In this test, 1200 °C is the most suitable temperature for the performance of the cement. Through the experimental comparison of different holding time, it is known that with the prolonging of the holding time, the microstructure and actual performance of the cement are continuously enhanced. Comprehensive consideration: the ratio of steel slag in cement ratio is 10%, sintering temperature is 1200 °C, and heat preservation is 2h. The steel slag cement prepared under this condition has the strongest performance.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4209
Author(s):  
Anca Becze ◽  
Vanda Liliana Babalau-Fuss ◽  
Cerasel Varaticeanu ◽  
Cecilia Roman

Circular economy principles are based on the use of by-products from one operation as the raw materials in another. The aim of this work is to obtain extracts with high antioxidant capacity and resveratrol content for the superior capitalization of the biomass of Feteasca regala leaves obtained during vineyard horticultural operations in spring. In order to obtain a high-quality extract at an industrial level, an optimal extraction process is needed. Central composite design (CCD) was used for the experiment design, which contained three independent variables: the ratio of extraction solvent to solid matter, temperature (°C) and time (minutes). The evaluation of extracts was done by measuring the total antioxidant capacity of the extracts using photo-chemiluminescent techniques, and the resveratrol content using liquid chromatography. Process optimization was done using response surface methodology (RSM). Minitab software version 17.0 was used for the design of experiments and data analysis. Regression analysis showed that the model predicts 87.5% of the variation for resveratrol and 96% for total antioxidant capacity (TAC). The temperature had the biggest influence on the extraction yield. The optimal operational conditions for the extraction method applied had the following conditions: ratio e/m 2.92; 43.23 °C and 55.4 min. A maximum value of 34,623 µg ascorbic acid equivalent (AAE) /mL total antioxidant capacity and 182.4 µg/mL resveratrol content were obtained when the optimal extraction parameters where used. The values obtained in experiments proved that by using RSM an accurate model can be obtained for extraction of Feteasca regala leaves.


2013 ◽  
Vol 779 ◽  
pp. 14-21 ◽  
Author(s):  
M. Reza Hormozi-Nezhad ◽  
Hossein Robatjazi ◽  
Mehdi Jalali-Heravi

2012 ◽  
Vol 161 ◽  
pp. 82-87 ◽  
Author(s):  
Yuan Heng Guo ◽  
Hua Zheng ◽  
Hong Zhang ◽  
Li Yi Ma ◽  
Juan Han ◽  
...  

For more efficient and economical extraction of cochineal dye, combined microwave-ultrasonic wave extraction was applied. It was approached 4 factors as microwave power, treated time, materials-to-liquid ratio and ultrasonic wave power. Results showed that the optimal condition individually for cochineal dye extraction was at 400W microwave power, 17min treated time, 1:8 materials-to-liquid ratio and 600W ultrasonic wave power. On the basis of single factor test, RSM optimization of the extraction was achieved at 464W microwave power, 18.48min treated time, 1:8.23 materials-to-liquid ratio and 627W ultrasonic wave power. The verification was very approximate to the predicted value from the modelling regression equation. And the best extraction grade was tesified as 4 times.


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