Box-Behnken Approach Research Articles

Influence of Carbon Nanofibers on the Shear Strength and Comparing Cohesion of Direct Shear Test and AFM

The stabilization and enhancement of the engineering properties of fine and coarse grained soil has heavily relied on reinforcement and admixture materials. This study discusses the effect of the additive of Carbon nanofibers (CNF) on the characteristics of soils in terms of shear strength. The content of CNF was changed within the range of 0.05 to 0.2% by total dry weight of the reinforced samples. In achieving the objective of minimizing the number of experimental runs and thus conserve material, time as well as overall cost, the Box–Behnken approach was chosen as the method for statistical prediction. The scanning electron microscopy (SEM) and Atomic force microscopy (AFM) has been utilized in studying features of CNF in stabilized soil samples and force at the origin of the cohesion (c) of soil. Test results reveal that the increases peak and residual shear strength of the reinforcement soil samples were increased with an increase in the CNF content. The pre-eminence of ionic correlation forces in the cohesion of soil was confirmed by the force (cohesion) measurements by (AFM). The statistical prediction’s relatively high correlation coefficients justified the results.

Methodized depiction of design of experiment for parameters optimization in synthesis of poly(Nvinylcaprolactam) thermoresponsive polymers

Recently, common research on stimuli-responsive polymers comprising thermoresponsive polymers has been widely investigated. In this research study, the synthesis process parameters of poly(Nvinylcaprolactam) (PNVCL) a thermoresponsive polymer, has been engaged for optimization as an attempt. The response surface methodology (RSM), has been employed in the identification of the elevated factors affecting on PNVCL production conversion (%) yield. Four independent process variables including monomer concentration, initiator concentration, polymerization temperature and time were studied. Various polymerization combination factors consist of a set of experiment runs were discussed using the Box–Behnken approach in Minitab 16. The study efficiently established the procedure and recompenses of RSM, for the estimation of process response. The optimum value for the most significant (temperature and time) variables for maximum PNVCL conversion (%) yield were obtained to be ∼80 °C and 92.5 min, respectively. Monomer and initiator concentrations were hardly effective on the (%) yield.

OPTIMIZATION OF GASTROADHESIVE DELIVERY SYSTEM FOR NARROW ABSORPTION WINDOW DRUG USING NATURAL POLYMERS

A system comprising mechanisms of gastric retention by gastroadhesion has been investigated employing combination of hibiscus esculentus mucilage and xanthan gum for diltiazem hydrochloride. Various formulations of diltiazem hydrochloride were prepared by wet granulation technique using Box-Behnken approach and were tested for compatibility, swelling behaviour, in vitro drug release, mucoadhesive strength and accelerated stability. The percent cumulative drug release at 8th hr (Y1), time to release 80 % of drug (Y2), mucoadhesive strength (Y3) and mucoadhesive time (Y4) were used as the formulation responses in order to optimize the formulation. The accelerated stability studies revealed that the tablets retained their characteristics even after stressed storage conditions. The DLT mucoadhesive matrices were 49.99 mg hibiscus esculentus mucilage, 44.97 mg xanthan gum and 4.48 ton compression load fulfilled the optimal criteria of best sustained release rate and bioadhesive characteristics with t80% of 7.6 h, Q8h of 89.83 % and bioadhesive strength of 22.14 g.

Parametric optimization studies on drilling of sandwich composites using the Box–Behnken design

ABSTRACTThis study was carried out to investigate the parametric influence on the performance of drilling newly made sandwich composites. Sandwich composite was prepared by using steel and jute as reinforcements and polyester as the matrix material. Drilling experiments were carried out by considering input factors such as spindle speed, feed rate of the spindle, point angle of the drill and tool diameter. Three output factors, namely thrust force developed during drilling, surface roughness of the drilled hole and damage at the entrance surface, were studied. All output factors were optimized by using the Box–Behnken approach, and the best machining conditions were taken on the basis of the desirability approach. Confirmatory experiments were conducted and compared against the Box–Behnken model. The comparison showed only a minor error, and hence the optimization is satisfactory.

Application of Response Surface Methodology for Optimization of Water Treatment by Fe3O4/SiO2/TiO2 Core-Shell Nano-Photocatalyst

In the present work, Fe3O4/SiO2/TiO2 nano-photocatalyst with a core-shell structure was successfully used for the removal of Methylene Blue (MB) as a model organic pollutant from water. The resultant nanoparticles were characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, Brunauer–Emmett–Teller method, and Barrett–Joyner–Halenda method. Response surface methodology (Box–Behnken approach) was applied to optimize the removal of MB from water. This optimization was used to evaluate the effect of experimental variables and their interaction in achieving the optimum conditions in removal of MB from water which was measured via UV-visible spectroscopy. The optimum conditions were found to be at Si/Fe3O4 wt% = 17.35%, Ti/Fe3O4 wt% = 50.17%, and calcination temperature = 392°C with a 91.1% removal efficiency. Finally, a model was established and the predicted results from the model fitted well with the experimental values indicating that the optimization was successful.

Application of Design of Experiment (DoE) for Parameters Optimization in Compression Moulding for Flax Reinforced Biocomposites

Lately, widespread research on polymer composites that consist of natural fiber as reinforcement have been widely discussed. In this work, an attempt on optimizing the hot press forming process parameters using Response Surface Methodology (RSM) have been made to improve the mechanical properties of the woven flax/PLA composites. Three independent process variables, including moulding temperature, time and pressure were studied. Through the Box Behnken approach, a set of experiment runs based on various combination of compression moulding via Minitab 16 were established. As a results the optimum value for the variables of compression moulding technique parameters were 200°C, 3min and 30bar in order to yield 48.902kJ/m-2ofimpact strength.

Development and Optimization of Oral Gastroadhesive Matrices for Diltiazem Hydrochloride Using Some Natural Materials

The present aim of this wok was to formulate gastric retentive tablets by gastroadhesion with a view to provide better absorption employing combination of hibiscus esculentus mucilage and xanthan gum for diltiazem hydrochloride. Various formulations of diltiazem hydrochloride were prepared by wet granulation technique using Box-Behnken approach and were tested for compatibility, swelling behaviour, in-vitro drug release, mucoadhesive strength and accelerated stability. The percent cumulative drug release at 8th hr (Y1), time to release 80% of drug (Y2), mucoadhesive strength (Y3) and mucoadhesive time (Y4) were used as the formulation responses in order to optimize the formulation. The accelerated stability studies revealed that the tablets retained their characteristics even after stressed storage conditions. The DLT mucoadhesive matrices were 49.99 mg hibiscus esculentus mucilage, 44.97 mg xanthan gum and 4.48 ton compression load fulfilled the optimal criteria of best sustained release rate and bioadhesive characteristics with t80% of 7.6 h, Q8h of 89.83% and bioadhesive strength of 22.14 g. The formulated tablets ascertained first order kinetics and followed peppas mechanism.

In vitro zearalenone adsorption by a mixture of organic and inorganic adsorbents: application of the Box Behnken approach

Zearalenone (ZEA) adsorption by a mixture of organic (yeast cell wall) and inorganic (activated charcoal) adsorbents was evaluated by an incomplete Box Behnken (33) statistical design with a quintuplicate at the central point. The variables analysed were different ratios of adsorbents (yeast cell wall and activated charcoal) at 100:0, 87.5:12.5 and 75:25, pH (3.0, 4.5 and 6.0) and ZEA concentrations (300, 750 and 1,200 ng/ml). The adsorbent mixture at 75:25 showed higher efficiency for ZEA adsorption (≯96.1%) than the 87.5:12.5 ratio (81.3 to 93.7%) and with the pure yeast cell wall (78.1 to 55.7%). The significant variables were the ratio of adsorbent mixture and ZEA concentration. The effect of pH was not significant (P=0.05), indicating that the binding between ZEA and the adsorbent would be stable at different pH (3.0, 4.5 and 6.0). The quadratic model obtained by the Box Behnken (33) design can be used for predictive purposes, because it showed a non-significant deviation (P=49.54%) and a good correlation coefficient (R2=0.98), suggesting that the ZEA adsorption would be maximum (100%) when the adsorbent mixture is set at 75:25 and the ZEA concentration at 300 ng/ml. Although the predictive model showed that an increase in adsorption efficiency could occur in a smaller ZEA concentration (300 ng/ml), the mixture at the 75:25 ratio presented high efficiency (≯98%) in adsorption when high ZEA concentrations were used (1,200 ng/ml), indicating that these mixtures would be able to adsorb a wide range of ZEA concentrations. Therefore, this mixture of yeast cell wall and activated charcoal adsorbents at 75:25 might be a candidate for furtherin vivo testing.

Analysis and optimization of micro-geometry of miniature spur gears manufactured by wire electric discharge machining

Abstract This paper reports about the analysis and optimization of micro-geometry parameters (i.e. total profile deviation ‘Fa’ and accumulated pitch deviation ‘Fp’) of the wire electric discharge machined (WEDMed) fine-pitch miniature spur gears made of brass. Effects of four WEDM process parameters namely voltage, pulse-on time, pulse-off time and wire feed rate on the micro-geometry of the miniature gears were analyzed by conducting the experiments designed using Box–Behnken approach of response surface methodology (RSM). Analysis of variance study found all four input parameters significant. Larger deviations in profile and pitch were observed with higher values of the voltage and pulse-on time, and with lower values of wire feed rate and pulse-off time. Multi-performance optimization of WEDM parameters was done using the desirability analysis to minimize profile deviation and pitch deviation simultaneously. The values of Fa and Fp of the gear obtained by the confirmation experiment conducted at the optimized WEDM parameters were as 11.5 μm and 9.1 μm respectively. These values categorize the WEDMed gear having DIN quality number as 7 and 5 respectively for profile and pitch which are better than those obtained by the conventional miniature gear manufacturing processes.

Analysis and optimization of surface finish of wire electrical discharge machined miniature gears

This article reports about analysis and optimization of surface roughness parameters (i.e. average roughness Ra and maximum roughness Rt) of wire electrical discharge machined fine-pitch miniature spur gears made of brass. Effects of four wire electrical discharge machining process parameters (i.e. voltage, pulse-on time, pulse-off time and wire feed rate) on the surface roughness parameters of the miniature gears were studied by conducting 29 experiments with two replicates each and designed based on Box–Behnken approach of response surface methodology. Analysis of variance study found all four input parameters to be significant. Experimentally, the surface roughness has been found to increase with higher voltage and longer pulse-on time and decrease with longer pulse-off time and higher wire feed rate. Desirability analysis was used to optimize the wire electrical discharge machining parameters, so as to minimize the Ra and Rt simultaneously. Optimum values of Ra and Rt obtained from the confirmation experiments conducted at the optimized wire electrical discharge machining parameters are superior than the values reported in the literature. Artificial neural network model has been developed for prediction of the surface roughness of the wire electrical discharge machined miniature gears. Very close agreement was found among the surface roughness values predicted by response surface methodology and artificial neural network with the corresponding experimental values.

A Study of Pack Aluminizing Process for NiCrAlY Coatings Using Response Surface Methodology

Aluminizing process is widely used to provide additional Al deposition onto superalloy surface for enhanced oxidation and corrosion resistance. In this research, an aluminizing process—pack cementation process, is used to deposit Al onto the surface of NiCrAlY coatings for increasing environmental protection. The experiment is designed using Box-Behnken approach, in which three parameters, the Al content, Ni content of the pack powder, and the temperature of the process, are selected as factors; and the thickness and Al/Ni ratio of the coatings are selected as responses. The effects of the factors on the responses are analyzed and modeled empirically. It is found that these empirical models correlate well with the results from additional sets of experiment. These models can be used to produce aluminized NiCrAlY coatings with specific thicknesses and Al/Ni ratios.

Computation of interactive effects and optimization of process parameters for alkaline lipase production by mutant strain of Pseudomonas aeruginosa using response surface methodology

Alkaline lipase production by mutant strain of Pseudomonas aeruginosa MTCC 10,055 was optimized in shake flask batch fermentation using response surface methodology. An empirical model was developed through Box-Behnken experimental design to describe the relationship among tested variables (pH, temperature, castor oil, starch and triton-X-100). The second-order quadratic model determined the optimum conditions as castor oil, 1.77 mL.L−1; starch, 15.0 g.L−1; triton-X-100, 0.93 mL.L−1; incubation temperature, 34.12 °C and pH 8.1 resulting into maximum alkaline lipase production (3142.57 U.mL−1). The quadratic model was in satisfactory adjustment with the experimental data as evidenced by a high coefficient of determination (R2) value (0.9987). The RSM facilitated the analysis and interpretation of experimental data to ascertain the optimum conditions of the variables for the process and recognized the contribution of individual variables to assess the response under optimal conditions. Hence Box-Behnken approach could fruitfully be applied for process optimization.

Investigations on tool wear and material deposition aspects of TiC coating on aluminium by electro discharge coating process

This paper presents detailed investigations on material deposition rate (MDR) and tool wear rate (TWR) during the surface modification of aluminium workpiece by electrical discharge machining (EDM) process using TiC/Cu green compact tool electrode. Surface modification by EDM is a newly invented technique where the mechanical, chemical or tribological properties of the work surface can be enhanced. Intention is to transfer the constituent materials of the tool electrode on to the workpiece to create a hard, wear and corrosion resistance coating. This process is known as electro discharge coating (EDC). However, the input process parameters of EDC linking to MDR and TWR have not been understood properly, which is pointing towards the main objective to identify the behaviour of process parameters on MDR and TWR. The process is studied using Box-Behnken approach of response surface methodology (RSM) by varying four parameters namely: 1) peak current (4–10 A); 2) pulse-on-time (60–260 µs); 3) electrode composition (70% TiC/30% Cu, 60% TiC/40% Cu and 50% TiC/50% Cu); 4) compaction pressure (200 MPa, 300 MPa and 400 MPa) to study their effects on two response parameters namely material deposition rate and tool wear rate.

Submerged fermentation of laccase producing Streptomyces chartreusis using box-behnken experimental design

Response surface methodology was engaged for the optimization of diverse nutritional and physical parameters for laccase production by Streptomyces chartreusis strain NBRC 12753 in the submerged fermentation process. Screening of production parameters was executed using Plackett-Burman design and the variables with statistically momentous effects on laccase production were recognized. Variables such as Cupric sulphate, Pyrogallol and Yeast extract were selected for further optimization studies using Box-Behnken design. The multiple regression coefficients (R 2 ) had a value of 0.9606, indicating that the model could explain up to 96.06 % of the variability of the response. This methodology facilitated analysis of the experimental data to establish the optimum conditions for the process and understand the contribution of individual factors to evaluate the response under optimal conditions. Thus application of Box-Behnken approach appears to have potential usage in process application.

Conformational analysis of lignin models: a chemometric approach

In the present work, conformational analysis of lignin models was accomplished by considering four cross-link types (3-5', β-5', α-O-4 and β-O-4) and three monomer units [guaiacyl (G), p-hydroxyphenyl (H) and syringyl (S)]. Analysis involving the 3-5' and β-5' dimers was conducted following the standard procedure, i.e., rotating the monomers around the single bond. On the other hand, analysis of α-O-4 and β-O-4 dimers followed a distinct protocol with the aid of an interesting chemometric tool called Box-Behnken (BB) design. This methodology was applied with the aim of screening the most relevant dihedral angles. The results show that the conformational space for large systems with several dihedral angles can be mapped satisfactorily through the BB approach, reducing the number of dimensions to be treated at the quantum mechanical level. Furthermore, the quantum mechanics-chemometry-quantum mechanics (QM/BB/QM) method proposed here allows us to determine calculated torsional angles for lignin models in good agreement with crystallographic data for some model compounds.

Conversion of carbon dioxide and methane in biomass synthesis gas for liquid fuels production

The premise of this research is to find whether methane (CH4) and carbon dioxide (CO2) produced during biomass gasification can be converted to carbon monoxide (CO) and hydrogen (H2). Simultaneous steam and dry reforming was conducted by selecting three process parameters (temperature, CO2:CH4, and CH4:steam ratios). Experiments were carried out at three levels of temperature (800 °C, 825 °C and 850 °C), CO2:CH4 ratio (2:1, 1:1 and 1:2), and CH4:steam ratio (1:1, 1:2 and 1:3) at a residence time of 3.5 × 103 gcat min/cc using a custom mixed gas that resembles biomass synthesis gas, over a commercial catalyst. Experiments were conducted using a Box-Behnken approach to evaluate the effect of the process variables. The average CO and CO2 selectivities were 68% and 18%, respectively, while the CH4 and CO2 conversions were about 65% and 48%, respectively. The results showed optimum conditions for maximum CH4 conversion was at 800 °C, CO2:CH4 ratio and CH4:steam ratios of 1:1.

Ultrasound-assisted extraction of β-glucans from barley

The effect of operational variables on the ultrasound assisted extraction (UAE) of β-glucans from barley has been studied. The selected sonication variables were amplitude, time and cycle, and their combination represents different amounts of energy. The RSM Box–Behnken approach has been used to maximize both extraction yield and molecular weight (MW) of extracted β-glucans. The final results of the UAE reveal that the extraction yield depends on amplitude and especially on time; nevertheless MW decreases with time. The maximum extraction yield (66.1%) is achieved when delivering the maximum amount of energy (962.5 kJ/L), leading at the same time to the lowest MW (269 kDa). A reduction in the intensity of the treatment (energy output of 170 kJ/L) decreases the extraction yield up to 44.3% but increases the β-glucan MW to 461 kDa. The UAE process slightly improves the extraction yield of β-glucans and their MW compared to that obtained in a stirred tank extraction (3 h, 55 °C and 1000 rpm), the main effect of ultrasounds is related with the reduction of process time and energy consumption (3 min versus 3 h and 170 kJ/L versus 1460 kJ/L), what means a real process intensification, very interesting for the scale-up of the process.

Investigation on two-body abrasive wear behavior of titanium carbide filled glass fabric-epoxy composites- a Box-Behnken approach

The two-body abrasive wear behavior of Glass–Epoxy (G–E) composites has been evaluated by the addition of Titanium carbide (TiC) as a secondary reinforcement using pin-on disc equipment at an applied load of 5, 10 and 15N for various sliding distances (25, 50,75m) with 400 grit water proof Silicon Carbide (SiC) abrasive paper. By using Box- Behnken design the significant controlling factors and the interactions influencing the weight loss of the composites are identified. The results indicate that the addition of TiC in G-E composite increases the wear resistance considerably. It was found that highest wear resistance of G-E composite was achieved by the addition of 2wt. % TiC in particulate form. The presence of different wear mechanisms were analyzed and supported by SEM-micrographic examinations.

Conversion of paper sludge to ethanol by separate hydrolysis and fermentation (SHF) using Saccharomyces cerevisiae

The conversion of ethanol from paper sludge using the separate hydrolysis and fermentation (SHF) process with cellulase and Saccharomyces cerevisiae GIM-2 were investigated in this paper. Optimization strategy based on statistical experimental designs was employed to enhance degree of saccharification by enzymatic hydrolysis of paper sludge. Based on the Plackett–Burman design, hydrolysis time, substrate concentration and cellulase dosage were selected as the most significant variable on the degree of saccharification. Subsequently, the optimum combination of the selected factors was investigated by a Box-Behnken approach. A mathematical model was developed to show the effects of each factor and their combinatorial interactions on the degree of saccharification. The optimal conditions were hydrolysis time 82.7 h, substrate concentration 40.8 g L−1 and cellulase dosage 18.1 FPU g−1 substrate, and a degree of saccharification of 82.1% can be achieved. When hydrolysate was further fermented with S. cerevisiae GIM-2, the conversion rate of sugar to ethanol was 34.2% and the ethanol yield was 190 g kg−1 of dry paper sludge, corresponding to an overall conversion yield of 56.3% of the available carbohydrates on the initial substrate. The results derived from this study indicate that the response surface methodology is a useful tool for optimizing the hydrolysis conditions to converse paper sludge to ethanol.

Estudio del Efecto Combinado del Secado y Freido en las Propiedades de Tortillas Tostadas

A study of the combination of air drying and immersion frying, and their effect on decreasing fat content and other properties of toasted tortillas was done. Drying with hot air (35, 48 and 68 °C) at 2, 4 and 6 m/s was utilized to dry the tortillas, in which the final moisture content was in a range of 6-12%. Frying was conducted with initial moisture of 10% in the tortillas, at 140, 160 and 180 °C and process times of 30, 60, 90 and 120 s to get the toasted tortillas. Faster moisture loss during drying determined lower evaporation rates through the frying and vice versa. There was a significant effect of the drying conditions on the fried product. The toasted product had fat content lower than commercial products and similar quality attributes. Optimization of the process was carried out using a computer program and the Box-Behnken approach. Model results were compared with experimental data.