Box-Behnken Technique Research Articles

NUMERICAL MODELING OF WC-12% Co LASER ALLOYED CAST IRON IN HIGH TEMPERATURE SLIDING WEAR CONDITION USING RESPONSE SURFACE METHODOLOGY

The wear behavior of untreated and WC-12% Co laser alloyed nodular cast iron samples were analyzed using a high temperature pin-on-disc tribometer. Response surface methodology (RSM) based Box–Behnken technique was employed to minimize the sum of trials and to develop a mathematical model for the input process parameters namely sliding velocity, temperature and load. The interaction effects of the process parameters were investigated using the developed model. Further, the developed model was analyzed using analysis of variance. Scanning electron microscopy and energy dispersive spectrum were used for characterization. Laser alloyed samples showed a minimum wear rate ([Formula: see text] to [Formula: see text][Formula: see text]mm3/m) and friction coefficient (0.10 to 0.39) compared to untreated samples. The results of the validation test showed that the experimental results agreed well with predicted results of the developed mathematical model.

Factors That Control Condensate Production From Shales: Surrogate Reservoir Models and Uncertainty Analysis

SummaryRapid development of shales for the production of oils and condensates may not be permitting adequate analysis of the important factors governing recovery. Understanding the performance of shales or tight oil reservoirs producing condensates requires numerically extensive compositional simulations. The purpose of this study is to identify important factors that control production of condensates from low-permeability plays and to develop analytical “surrogate” models suitable for Monte Carlo analysis. In this study, the surrogate reservoir models were second-order response surfaces functionally dependent on the nine main factors that most affect condensate recovery in ultralow-permeability reservoirs. The models were developed by regressing the results of experimentally designed compositional simulations. The Box-Behnken (Box and Behnken 1960) technique, a partial-factorial method, was used for design of these experiments or simulations. The main factors that controlled condensate recovery from ultralow-permeability reservoirs were reservoir permeability, rock compressibility, initial condensate/gas ratio (CGR), initial reservoir pressure, and fracture spacing. Another main outcome of this paper was the generation of probability-density functions, and P10, P50, and P90 values for condensate recovery on the basis of the uncertainty in input parameters. The condensate-recovery P50 for rate-based outcome of a 5-B/D per fracture was found to be less than 10%.

Preventing Aggregation of Recombinant Interferon beta-1b in Solution by Additives: Approach to an Albumin-Free Formulation.

Aggregation suppressing additives have been used to stabilize proteins during manufacturing and storage. Interferonβ-1b is prone to aggregation because of being non-glycosylated. Aggregation behavior of albumin-free formulations of recombinant IFNβ-1b was explored using additives such as n-dodecyl-β-D-maltoside, Tween 20, arginine, glycine, trehalose and sucrose at different pH. Fractional factorial design was applied to select major factors affecting aggregation in solutions. Box-Behnken technique was used to optimize the best concentration of additives and protein. Quadratic model was the best fitted model for particle size, OD350 and OD280/OD260. The optimal conditions of 0.2% n-Dodecyl-β-D-maltoside, 70 mM arginine, 189 mM trehalose and protein concentration of 0.50 mg/ml at pH 4 were achieved. A potency value of 91% ± 5% was obtained for the optimized formulation. This study shows that the combination of n-Dodecyl-β-D-maltoside, arginine and trehalose would demonstrate a significant stabilizing and anti-aggregating effect on the liquid formulation of interferonβ-1b. It can not only reduce the manufacturing costs but will also ease patient compliance.

Shrinkage characteristics studies on conventional sintered zirconia toughened alumina using computed tomography imaging technique

Shrinkage is an important issue during sintering of ceramics as it affects the structural and mechanical properties. In the current work, the shrinkage characteristics of sintered zirconia toughened alumina (ZTA) compact produced by conventional powder forming process was investigated by using computed tomography imaging technique. The effect of process parameters such as weight percentage of zirconia added to toughened alumina, compaction pressure, and sintering temperature on ZTA was studied. The Box–Behnken technique in response surface methodology was used to develop the experimental design to analyze the shrinkage phenomena. The sintered samples were subjected to computed tomography scan and analyzed by using MIMICS Software wherein the three dimensional shrinkage of the ZTA composites was done. The mathematical regression model relating powder forming process parameters to the shrinkage was developed. It was observed that due to the effect of gravity, shrinkage is found to be 20% in the top for 1600°C sintered sample. From the study shrinkage of the sintered ZTA was influenced by the sintering temperature. Being a non-contact type digital measurement method the odds of error created by instrument or human was avoided. Shrinkage of three directional complex shapes can also be identified effectively with the help of solid modeling packages.

Optimization to develop multiple response hardness and compressive strength of zirconia reinforced alumina by using RSM and GRA

In this work the effect of powder forming process parameters of zirconia reinforced alumina composites on micro hardness and compressive strength was studied. The weight percentages of zirconia added to alumina, compaction pressure and sintering temperature are the process parameters selected for this analysis. Using Box–Behnken technique in Response Surface Methodology (RSM), seventeen experimental runs are developed. The sintering temperature and weight percentage of zirconia added to alumina are found to influence the responses. The influencing parameters were identified by using analysis of variance and Grey Relational Analysis (GRA). The regression model for both micro hardness and compressive strength are developed. The increasing amount of zirconia added to alumina matrix is found to enhance the compressive strength of the composite and reduces the hardness of composite. Also, multi response optimization to obtain higher hardness and compressive strength are done using both RSM and GRA.

Optimization of operating process parameters for instant brown rice production with microwave-followed by convective hot air drying

Nowadays, instant or quick cooking brown rice is a food product that has marketing potential due to the life style of new generation. This research mainly aimed to characterize, model and optimize the key processing conditions including water-rice ratio (WRR), microwave power level (MWL) and hot air temperature (HAT) for producing instant brown rice by applying Box-Behnken technique. The process responses comprised with color, rehydration ratio and textural qualities of products. The microscopic images of products were also determined. The result indicated that MWL caused the most intense effect on the rehydration ratio and textural qualities. Furthermore, the MWL and HAT influenced on the lightness while the WRR affected on the hardness of rehydrated samples. All three processing parameters significantly affected on the color intensity and stickiness of rehydrated rice. The optimal processing conditions for WRR, MWL and HAT were 1.44, 499.8 W and 89.99 °C respectively with 88% overall desirability.

Optimization of culture conditions for production of lipase by a newly isolated bacterium Stenotrophomonas maltophilia

The production of an extracellular lipase from the newly isolated Stenotrophomonas maltophilia was optimized via the statistical design method. During a screening program, the microorganism was isolated from soil samples, according to lipolytic activity on nutrient agar medium supplemented with Rhodamine B. It was identified using morphological and biochemical properties as well as 16S rDNA sequencing analysis. After the initial screening of 10 factors of the medium components, using Plackett–Burman design, results showed that four of them, included olive oil, peptone, yeast extract, and ferrous sulfate, exhibited significant effects on the lipase production by S. maltophilia. The level of each factor was subjected to optimization by using the Box–Behnken technique, and a 9.1-fold enhancement of lipase productivity (from 500U/ml to 4559U/ml) was achieved overall in the presence of optimum levels of the effective factors. Forty-three percent of capsaicin (initial concentration of 500mg/L) was converted to vanillylamine after treatment with the optimized medium (lipase activity 4559U/ml) for 18h.

Box-Behnken법을 이용한 E. coli 소독에서 전기-UV-초음파 복합 공정의 최적화

This experimental design and response surface methodology (RSM) have been applied to the investigation of the electro-UV-ultrasonic complex process for the disinfection of E. coli in the water. The disinfection reactions of electro-UV-ultrasonic process were mathematically described as a function of parameters power of electrolysis (X1), UV (X2), and ultrasonic process (X3) being modeled by use of the Box-Behnken technique, which was used for fitting 2nd order response surface model. The application of RSM yielded the following regression equation, which is empirical relationship between the residual E. coli number (Ln CFU) in water and test variables in coded unit: residual E. coli number (Ln CFU) = 23.69 3.75.Electrolysis 0.67.UV 0.26. Ultrasonic 0.16.Electrolysis.UV + 0.05.Electrolysis.Ultrasonic + 0.27.Electrolysis + 0.14.UV 0.01.Ultrasonic). The model predictions agreed well with the experimentally observed result (R = 0.983). Graphical 2D contour and 3D response surface plots were used to locate the optimum range. The estimated ridge of maximum response and optimal conditions for residual E. coli number (Ln CFU) using ‘numerical optimization' of Design-Expert software were 1.47 Ln CFU/L and 6.94 W of electrolysis, 6.72 W of UV and 14.23 W of ultrasonic process. This study clearly showed that response surface methodology was one of the suitable methods to optimize the operating conditions and minimize the residual E. coli number of the complex disinfection.

전기-UV 복합 공정을 이용한 E. coli 소독 : 실험계획법중 박스-벤켄법을 이용한 소독 특성 및 최적화

The experimental design and response surface methodology (RSM) have been applied to the investigation of the electro-UV complex process for the disinfection of E. coli in the water. The disinfection reactions of electro-UV process were mathematically described as a function of parameters power (<TEX>$X_1$</TEX>), NaCl dosage (<TEX>$X_2$</TEX>), initial pH (<TEX>$X_3$</TEX>) and disinfection time (<TEX>$X_4$</TEX>) being modeled by use of the Box-Behnken technique. The application of RSM using the Box-Behnken technique yielded the following regression equation, which is an empirical relationship between the residual E. coli number and test variables in actual variables: Ln (CFU) = 23.57 - 0.87 power - 1.87 NaCl dosage - 2.13 pH - 2.84 time - 0.09 power time - 0.07 NaCl dosage pH + 0.14 pH time + 0.03 <TEX>$power^2$</TEX> + 0.47 NaCl <TEX>$dosage^2$</TEX> + 0.20 <TEX>$pH^2$</TEX>+ 0.33 <TEX>$time^2$</TEX>. The model predictions agreed well with the experimentally observed result (<TEX>$R^2$</TEX> = 0.9987). Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the E. coli disinfection using canonical analysis was Ln 1.06 CFU (power, 15.40 W; NaCl dosage, 1.95 g/L, pH, 5.94 and time, 4.67 min). To confirm this optimum condition, the obtained number of the residual E. coli after three additional experiments were Ln 1.05, 1.10 and Ln 1.12. These values were within range of 0.62 (95% PI low)~1.50 (95% PI high), which indicated that conforming the reproducibility of the model.

Optimal design of a plate heat exchanger with undulated surfaces

The purpose of this study is to suggest a general method for the optimal design of a plate heat exchanger ( PHE) with undulated surfaces that complies with the principles of sustainability. A previously validated CFD code is employed to predict the heat transfer rate and pressure drop in this type of equipment. The computational model is a three-dimensional narrow channel with angled triangular undulations in a herringbone pattern, whose blockage ratio, channel aspect ratio, corrugation aspect ratio, angle of attack and Reynolds number are used as design variables. To limit the number of simulations needed, the Box–Behnken technique is employed. An objective function that linearly combines heat transfer augmentation with friction losses, using a weighting factor that accounts for the cost of energy, is employed for the optimization procedure using response surface methodology ( RSM). New correlations are provided for predicting Nusselt number and friction factor in such PHEs. The results are in very good agreement with published data. Finally, optimal design specifications are suggested for a range of Re for two values of the weighting factor.

Fused deposition modelling using direct extrusion

In the present work, a process based on the principle of polymer extrusion is developed: the extruder deposition process (EDP). This system uses a screw extruder to deposit the material on a computer-controlled positioning system to build components. Experiments (Box–Behnken technique is used for experimental design) are carried out to study the influence of three process variables: nozzle temperature, chamber temperature and road gap on bond strength (inter-road and interlayer) and surface finish. Surface roughness and ultimate tensile strength values are measured for test specimens. Analysis of variance (ANOVA) is used to determine the significance of process variables. It is concluded that the developed EDP eliminates many of the shortcomings of the systems developed based on the principles of extrusion and produces components having higher bond strength than that achieved in commercial fused deposition modelling (FDM) systems.