Quadratic Mathematical Model Research Articles

Optimal Design of Multilevel Composite Lubrication Structures on Sliding Guide Rail Surfaces

To optimize the crawling phenomenon of slides under circumstances of low speed and a heavy load, a composite lubrication structure is adopted to alleviate the crawling phenomenon. The response surface optimal-design method establishes a quadratic mathematical model for multistage composite lubrication structure parameters, including crawling time and average friction coefficient. The optimal combination parameters of multistage composite lubrication structures have been determined. The optimal ratio of lubricating oil to molybdenum disulfide (MoS2) has been identified, and a composite lubrication structure has been proposed to enhance the crawling phenomenon and friction performance of sliding guide rails under medium-speed and medium-load conditions. These research outcomes indicate that when low speed and a heavy load are present, the crawling time and friction coefficient initially diminish and subsequently augment as the width, spacing, and cycle length of the sinusoidal texture and the diameter of the hexagonal pit expand. The optimum configuration of multistage composite lubrication structures is as follows: The width of the sine-wave texture b amounts to 0.15 mm, the cycle length e is 2 mm, the spacing c is 1.5 mm, and the diameter of the hexagonal pit d is 0.2 mm. When the mass ratio of guide oil to MoS2 is 2:1, it exhibits supreme crawling resistance and antifriction attributes. In circumstances involving a medium load and speed, multistage composite lubrication structures manifest pre-eminent friction performance. These data can steer the design of multistage composite lubrication structures on the surface of slide rails.

Application of cloud point extraction coupled with derivative spectrophotometry to remove binary mixture of Cresol Red and Methyl Orange dyes from aqueous solutions: Box–behnken design optimization

Cloud point extraction (CPE) was employed to eliminate Cresol Red (CR) and Methyl Orange (MO), as anionic dyes in a binary mixture from aqueous solutions. To remove these dyes Triton X-100 and NaCl at pH 5.7 were utilized. In this vein, wavelengths of 365 nm and 520 nm were respectively selected for CR and MO using the derivative spectrophotometer and first-order derivatives. According to based on the first-order derivative spectrophotometry, the recoveries rised from 94.3 to 99.5 % for CR and from 94.6 to 99.1 % for MO. In the following, the response surface methodology was administered to investigate the effect of surfactant concentration, temperature, and time on the dyes' elimination process. The quadratic mathematical model was obtained from the Box-Behnken design (BBD) matrix and developed to estimate the impact of each variable and its relationship with the elimination parameters. Later, coefficients of determination (R2) ≥0.97 were obtained using model equations and comparison between predicted and empirical values. Analysis of variance estimated the models’ significance and anticipation while processing the study variables. Based on the results, the model of pseudo-first-order in kinetic modelling can best describe dyes adsorption among the studied models. The analyzed dyes adhere to the Langmuir model with correlation values of 0.86 for CR and 0.87 for MO. The monolayer capacity (Qmax) was determined as 0.77 mol/mol for CR and 26.41 mol/mol for MO.

Electrochemical oxidation of methyl blue dye by stainless steel tubes bundle anode

Methyl blue dye was successfully electrochemically oxidised in a flow-through batch circulation process using a stainless-steel tube bundle anode. The experimental design and process optimisation were conducted according to the response surface Methodology with Rotatable Central Composite Design method. The controlled variables in this study were the solution flow rate, applied current, electrolyte concentration, and time. A quadratic mathematical model expressing the removal percentage as a function of the operating variables and their interactions was constructed from the experimental data. The accuracy of the model was confirmed using residual plots and an R2 value of 0.8526. Solution flow rate was found to promote the removal percentage up to 1.5 l/min, the applied current promoted the removal efficiency significantly up to 400 mA, the electrolyte concentration had a positive effect up to 2 M, and the removal efficiency increases generally with time, reaching the equilibrium removal percentage at 67.121 min. The optimum conditions for the target with the highest removal percentage of 91.333% were found to be 1.5 l/min solution flow rate, 400 mA applied current, 2 M electrolyte solution, and 67.121 min.

Electrochemical advanced oxidation of 2,4-D herbicide and real pesticide wastewater with an integrated anodic oxidation/heterogeneous electro-Fenton process

Pesticide wastewater is accused of polluting receiving waters with toxic and non-biodegradable organic pollutants. The present study has developed an integrated electrochemical oxidation process based on PbO2 anodic oxidation and Fe/SBA-15 heterogeneous electro-Fenton (PbO2/EF-(Fe/SBA-15)) for synergistic treatment of pesticide wastewater. PbO2 electrocatalyst was prepared by anodic deposition method and Fe/SBA-15 catalyst was synthesized by incipient wetness impregnation method. To optimize and model the removal of 2,4-D, a quadratic mathematical model by orthogonal central composite design (CCD) was proposed and validated. In optimal conditions including solution pH = 5, H2O2 concentration = 2000 mg/L, applied current = 10 mA/cm2, Fe/SBA-15 dose = 1.25 g/L and 2,4-D concentration = 30 mg/L, the experimental removal efficiency of 2,4-D after 35 min of reaction in the PbO2/EF-(Fe/SBA-15) process was 99.85 %. Moreover, the kinetics of 2,4-D removal in the integrated PbO2/EF-(Fe/SBA-15) process was about 3.84 times faster than the separate PbO2 anodic oxidation, confirming a remarkable degradation synergy. The mineralization of 2,4-D was confirmed by LC-MS and TOC analyses, and considering the identified intermediates, the possible degradation pathways of 2,4-D to CO2 and H2O were suggested. Real pesticide wastewater treatment was studied under optimal conditions. COD removal efficiency in PbO2/EF-(Fe/SBA-15) process and PbO2 anodic oxidation was 71.2 % and 32.5 %, respectively. Also, the energy consumption (EC) of these two processes was 17 kWh/kg COD and 38 kWh/kg COD, respectively. The results of this study suggest the integrated PbO2/EF-(Fe/SBA-15) process is a practical and cost-effective process for non-biodegradable pesticide wastewater treatment.

Experimental Study on Permeability Characteristics of Mudstone under High Temperature Overburden Condition

High-temperature treatment significantly impacts the permeability of mudstone. The permeability of mudstone after exposure to high temperatures is closely influenced by the temperature it experiences and the stress state it is subjected to. This study examines the change in macroscopic physico-mechanical properties of mudstone with temperature following high-temperature treatment. Additionally, we conducted experimental research on the gas and water seepage behavior of mudstone specimens from the top of the coal seam of Taiyuan Group–Shanxi Group in the Ordos Basin. The coal-rock mechanics-permeability test system TAWD-2000 was employed for this purpose. Subsequently, we analyzed the evolution of mudstone permeability after high-temperature treatment with consideration to temperature, axial pressure, and other influencing factors. The findings reveal that gas permeability of mudstone gradually increases with increasing temperature, while water permeability initially decreases and subsequently increases. Furthermore, both gas and water permeability of mudstone exhibit a trend of decreasing and then increasing with rising stress levels after undergoing the same high-temperature treatment. We constructed a quadratic mathematical model with a goodness of fit of 99.4% and 89.2% to describe the relationship between temperature–stress coupling and mudstone gas and water permeability. This model underscores the significance of temperature–stress coupling on mudstone permeability and provides valuable guidance for numerically calculating the gas–water transport law of peripheral rock in the underground coal gasification process and its practical application in engineering.

Optimization of the Vacuum Fractional Distillation Process for Enhancing the α-Guaiene of Patchouli Oil with Response Surface Methodology

α-guaiene is one of the primary sesquiterpene compounds used as a flavor and fragrance agent in patchouli oil. The fraction of patchouli oil that is rich in α-guaiene has been successfully isolated. In the present work, α-guaiene was isolated from crude patchouli oil through vacuum fractional distillation followed by GC-MS identification. Three important process parameters—feed volume, reflux ratio, and applied run pressure—were investigated and optimized using Box–Behnken design. The research methodology was an experimental laboratory using response surface methodology (RSM) with a feed volume level from 75 mL to 125 mL, a reflux ratio from 10:1 to 30:1, and an applied run pressure from 5 mmHg to 15 mmHg. The α-guaiene-enriched fraction was found in the first distillate fraction patchouli. The optimum condition that generated α-guaiene fraction at 44.70% purity was the treatment with a feed volume of 75 mL, a reflux ratio of 24:1, and applied run pressure of 14.80 mmHg. Results indicated that feed volume did not significantly affect the α-guaiene content, while the applied run pressure and reflux ratio used had a significant effect. A quadratic mathematical model with R2 0.861 and validation 96.14% was suitable for predicting the optimum α-guaiene fraction content during the vacuum fractional distillation process.

Advanced Optimization of Surface Characteristics and Material Removal Rate for Biocompatible Ti6Al4V Using WEDM Process with BBD and NSGA II.

Machining titanium alloy (Ti6Al4V) used in orthopedic implants via conventional metal cutting processes is challenging due to excessive cutting forces, low surface integrity, and tool wear. To overcome these difficulties and ensure high-quality products, various industries employ wire electrical discharge machining (WEDM) for precise machining of intricate shapes in titanium alloy. The objective is to make WEDM machining parameters as efficient as possible for machining the biocompatible alloy Ti6Al4Vusing Box-Behnken design (BBD) and nondominated sorting genetic algorithm II (NSGA II). A quadratic mathematical model is created to represent the productivity and the quality factor (MRR and surface roughness) in terms of varying input parameters, such as pulse active (Ton) time, pulse inactive (Toff) time, peak amplitude (A) current, and applied servo (V) voltage. The established regression models and related prediction plots provide a reliable approach for predicting how the process variables affect the two responses, namely, MRR and SR. The effects of four process variables on both the responses were examined, and the findings revealed that the pulse duration and voltage have a major influence on the rate at which material is removed (MRR), whereas the pulse duration influences quality (SR). The tradeoff between MRR and SR, when significant process factors are included, emphasizes the need for a reliable multi-objective optimization method. The intelligent metaheuristic optimization method named nondominated sorting genetic algorithm II (NSGA II) was utilized to provide pareto optimum solutions in order to achieve high material removal rate (MRR) and low surface roughness (SR).

Catalytic ozonation process using modified activated carbon as a cataly s t for the removal of sarafloxacin antibiotic from aqueous solutions

Sarafloxacin (SAR) is an antibiotic from the fluoroquinolone group and is also one of the most widely used antibiotics in veterinary medicine. Potential performance and appropriate effectiveness have made SAR a special place among antibiotics. Antibiotic residues in the environment cause many problems, the most important of which is antibiotic resistance. Therefore, it is necessary to remove antibiotic residues from the environment. Response surface methodology (RSM) was utilized as a mathematics and statistics approach to optimize the removal efficiency of SAR using the catalytic ozonation process. The obtained regression equation for the response was the quadratic mathematical model. The coefficient of determination (R2), adjusted R2, and predicted R2 were obtained at 0.9939, 0.9917, and 0.9855, respectively. The maximum removal efficiency of 99.3% was obtained under optimum conditions, including a SAR concentration of 30.0 mg L-1, ozone dose of 1.5 mg min-1, catalyst dose (modified activated carbon) of 600 mg L-1, pH of 5.0, and reaction time of 30 min. According to the obtained results, the catalytic ozonation process as a suitable technique can efficiently remove SAR and other pharmaceutical compounds.

Surface characteristics optimization of biocompatible Ti6Al4V with RCCD and NSGA II using die sinking EDM

Machining of titanium alloy grade V (Ti6Al4V) is very difficult by conventional metal cutting process due to low thermal conductivity, ability to retain strength at elevated temperature, tendency to work harden. This may result in high heat at the cutting zone and the generation of thermal stresses. Therefore, in the present research die-sinking electrical discharge machining is used to machine Ti6Al4v alloy. A non-dominated sorting genetic algorithm (NSGA II) coupled with rotary central composite design (RCCD) based on response surface methodology (RSM) is employed to optimize machining parameters in die-sinking electrical discharge (EDM) machining of Ti6Al4V. A quadratic mathematical model has been developed for material removal rate (MRR) and surface roughness (Ra) in terms of peak current (I), pulse on time (Ton) and pulse off time (Toff) as independent input parameters. Die-sinking EDM experiments are planned using RCCD based on response surface methodology. Results revealed that peak current is the most influencing EDM parameter on both MRR and Ra with PC of 35.86% and 57.10% respectively. MRR continuously increases with peak current. MRR firstly decreases and then increases with an increase in Ton. Ra continuously increases with peak current and starts decreasing after a coded value of 1.5. The Optimization result obtained by NSGA II is validated through confirmation experiments which are in good agreement with the experimental value with an absolute error of 6% and 4.8% in MRR and Ra respectively.

Response surface optimisation of biodiesel synthesis using biomass derived green heterogeneous catalyst

Although homogeneous alkali-catalysed transesterification is the typical process used in biodiesel production, it caused complications in downstream separation processes and an oversupply of glycerol as a by-product. The present work studied the synthesis of a novel sulfonated biomass-derived solid acid catalyst and its application in biodiesel production via interesterification of oleic acid. Solid acid catalysts were prepared by direct sulfonation via thermal treatment with concentrated sulfuric acid. The design of experiments was conducted via four-factors central composite design (CCD) coupled with response surface methodology (RSM) analysis. The parameters considered for optimisation included carbonisation and sulfonation temperatures, catalyst loading and reaction time, each varied at five levels. The maximum yield of fatty acid methyl ester (FAME) was obtained using optimum parameters as carbonisation temperature of 586 °C, sulfonation temperature of 110 °C, catalyst loading of 10.5 wt.% and reaction time of 7 h was 54.3 % based on the theoretical ester formation. A quadratic mathematical model in RSM was successfully established that can make effective predictions about the anticipated biodiesel yield. This study proved that the low-cost heterogeneous catalyst derived from biomass waste with a simple production route could catalyse the interesterification process under moderate process conditions.

Electrochemical oxidation of palm oil mill effluent using platinum as anode: Optimization using response surface methodology

This work investigates the electrochemical oxidation of palm oil mill effluent (POME) treatment using platinum (Pt) as anode and graphite as a cathode. The response surface methodology was used to investigate the relationships between different factors conditions (voltage, electrolysis time and chemical support) and responses of the treatment (chemical oxygen demand reduction, colour removal, and total oil removal). A quadratic mathematical model was chosen for all responses using Box-Behnken Design (BBD) with R2 0.9853 for COD reduction, R2 0.9478 for colour removal and R2 0.9185 for total oil removal. According to Derringer's function desirability, under the optimum condition (Voltage 15, electrolysis time 2 h, and 19.95 mg/L NaCl) of POME treatment, 84% of COD reduction, 98% of colour removal and 99% total oil of removal could be achieved. These results indicate that platinum as an anode material is effective for the electrochemical oxidation treatment of POME.

Determination of the Optimum Blend Ratio of Diesel, Waste Oil Derived Biodiesel and 1-Pentanol Using the Response Surface Method

Higher alcohols can be included as a third component in biodiesel-diesel mixtures to improve fuel properties and reduce emissions. Determining the optimum concentrations of these fuels according to the purpose of engine use is important both environmentally and economically. In this study, eight different concentrations of diesel (D), waste oil derived biodiesel (WOB), and 1-pentanol (P) ternary mixtures were determined by the design of experimental method (DOE). In order to determine the engine performance and exhaust emission parameters of these fuels, they were tested on a diesel engine with a constant load of 6 kW and a constant engine speed of 1800 rpm. Using the test results obtained, a full quadratic mathematical model with a 95% confidence level was created using the Response Surface Method (RSM) to predict five different output parameters (BSFC, BTE, CO, HC, and NOx) according to the fuel mixture ratios. The R2 accuracy values of the outputs were found at the reliability level. According to the criteria that BTE will be maximum and BSFC, CO, HC, and NOx emissions will be minimum, the optimization determined that the fuel mixture 79.09% D-8.33% WOB-12.58% P concentration (DWOBPopt) will produce the desired result. A low prediction error was obtained with the confirmation test. As a result, it is concluded that the optimized fuel can be an alternative to the commonly accepted B7 blend and can be used safely in diesel engines.

Optimization of Mechanical Extraction by Response Surface Methodology and Oil Yield Characterization from Single‐Grain Castor Seed

AbstractThe application of castor oil in various fields and the development potential in renewable energy have attracted large attention, and castor oil extraction has become a research focus. The objective of this study is to determine the relationship between important parameters during single grain extrusion and to obtain the maximum oil yield. Mechanical compression tests are conducted by a texture analyzer. Response surface methodology is used to optimize the process variables. A four‐factor three‐level Box–Behnken design is used to generate factor combinations. A quadratic mathematical model between each variable and oil yield is developed. The significance of each interaction term is assessed by analysis of variance. The model's oil yield prediction accuracy is verified by tests. The highest oil yield of 30.18% is obtained under strain 94.97%, speed 0.1 mm s−1, dwell time 480 s, and drying at 20 °C. The determination coefficients (R2 = 0.9885; R2Adj = 0.8979; R2Pre = 0.8782) indicate the fitted quadratic mathematical model has a good correlation between experimental and predicted values. Lack of fit (0.9998) term is not significant and indicates the model reliability. Predicted oil yield value (30.18%) is close to experimental testing value (31.47%), which further demonstrates the mathematical model reliability.Practical applications: The extracted castor oil can be used for industrial research such as biodiesel. Castor seed is rich in oil content. Optimization of process parameters can improve oil recovery rate of castor seed. The developed model in this study provides a basic reference for improvement equipment related to the oil extraction.

Statistical optimization of operating parameters of microbial electrolysis cell treating dairy industry wastewater using quadratic model to enhance energy generation

The performance of Microbial electrolysis cell (MEC) is affected by several operating conditions. Therefore, in the present study, an optimization study was done to determine the working efficiency of MEC in terms of COD (chemical oxygen demand) removal, hydrogen and current generation. Optimization was carried out using a quadratic mathematical model of response surface methodology (RSM). Thirteen sets of experimental runs were performed to optimize the applied voltage and hydraulic retention time (HRT) of single chambered batch fed MEC operated with dairy industry wastewater. The operating conditions (i.e) an applied voltage of 0.8 V and HRT of 2 days that showed a maximum COD removal response was chosen for further studies. The MEC operated at optimized condition (HRT- 2 days and applied voltage- 0.8 V) showed a COD removal efficiency of 95 ± 2%, hydrogen generation of 32 ± 5 mL/L/d, Power density of 152 mW/cm2 and current generation of 19 mA. The results of the study implied that RSM, with its high degree of accuracy can be a reliable tool for optimizing the process of wastewater treatment. Also, dairy industry wastewater can be considered to be a potential source to generate hydrogen and energy through MEC at short HRT.

Оптимизация условий мицеллярно-ферментативной экстракции пектина из плодов боярышника ( Crataegus monogyna Jacq.)

Introduction. Commercial pectin is usually obtained from apples or citrus fruits. However, some wild fruits, such as hawthorn, are also rich in pectin with valuable nutritional and medical properties. The research objective was to study and improve the process of combined surfactant and enzyme-assisted extraction of pectin from hawthorn fruits.
 Study objects and methods. The study involved a 1% solution of Polysorbate-20 surfactant and a mix of two enzymes, namely cellulase and xylanase, in a ratio of 4:1. The response surface methodology with the Box-Behnken experimental design improved the extraction parameters. The experiment featured three independent variables – temperature, time, and solvent-to-material ratio. They varied at three levels: 20, 40, and 60°C; 120, 180, and 240 min; 15, 30, and 45 mL per g. Their effect on the parameters on the pectin yield was assessed using a quadratic mathematical model based on a second order polynomial equation.
 Results and discussion. The response surface methodology made it possible to derive a second order polynomial regression equation that illustrated the effect of extraction parameters on the yield of polyphenols. The regression coefficient (R2 = 98.14%) and the lack-of-fit test (P > 0.05) showed a good accuracy of the model. The optimal extraction conditions were found as follows: temperature = 41°C, time = 160 min, solvent-to-material ratio = 32 mL per 1 g. Under the optimal conditions, the predicted pectin yield was 14.9%, while the experimental yield was 15.2 ± 0.4%. The content of galacturonic acid in the obtained pectin was 58.5%, while the degree of esterification was 51.5%. The hawthorn pectin demonstrated a good complex-building ability in relation to ions of copper (564 mg Cu2+/g), lead (254 mg Pb2+/g), and cobalt (120 mg Co2+/g).
 Conclusion. Combined surfactant and enzyme-assisted extraction made improved the extraction of pectin from hawthorn fruits. The hawthorn pectin can be used to develop new functional products.

Separation of super clean coal with two-stage cyclones and related characteristics

ABSTRACT To recover super clean coal from raw coal slime of 28.53% ash, in this study, single factor experiment and response surface optimization experiment was used to design and optimize the design parameters of the two-stage cyclones for the separation and recovery of super clean coal. A quadratic mathematical model between the ash of super clean coal and the design parameters of the cyclones was established. Considering the minimum ash content as the optimization index, the following optimal experimental conditions were obtained: minimum ash content could reach 2.55%, which represented 5.35% recovery of the whole sample. The migration law of particles of different sizes, densities in classification and separation process, and the principle of preparation of super clean coal were explored under optimal conditions. Through the separation effect of the second-stage, overflow with particle size ≥ 0.125 mm could effectively recover super clean coal. However, the separation density was increased, and the separation effect was weakened when the particle was small. Therefore, to effectively recover super clean coal, sieving and desliming are necessary.

Microstructure and mechanical properties of PA6/NBR nanocomposites fabricated by friction stir processing

Thermoplastic elastomer (TPE) based on polyamid6 (PA6) / acrylonitrile-butadiene rubber (NBR) containing 5% wt nanoclay (Closite 30B) have been prepared via friction stir process (FSP). In this study, the essential work of fracture (EWF) approach was employed to investigate the fracture behavior of PA6/NBR nanocomposites. Also, the modulus strength of specimens was modeled by response surface methodology (RSM), considering three input variables including rotational speed (ω), traverse speed (S), and shoulder temperature (T). Thus, a quadratic mathematical model between input variables (ω, S and T) and response (modulus strength) of PA6/NBR/clay nanocomposites was achieved. Moreover, the morphology of the PA6/NBR blends containing 5% wt was investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show that a sample of PA6/NBR thermoplastic elastomer (TPE) containing 5% wt nanoclay at maximum tensile strength exhibited the maximum specific essential work of fracture (we) and specific non-essential work of fracture (wp). Also, the results of the RSM method demonstrate that the optimum condition of the process was found to be at including rotational speed (ω), traverse speed (S), and shoulder temperature (T) of 1200 rpm, 25mm/min, and 146 ℃, respectively. Thus, under the condition optimum, maximum modulus strength of 658 MPa was obtained.

Intensified transesterification of castor oil using ultrasonic horn: response surface methodology (RSM) based optimization

ABSTRACT Intensification of synthesis of biodiesel from sustainable feedstock using ultrasound and optimization based on RSM is important to develop sustainable and economical processes as an alternative to fossil-based fuels. The current work deals with transesterification of castor oil focusing on intensification based on the application of ultrasonic horn and optimization using RSM. The parameters applied in the study for optimization are time (X1), temperature (X2), molar ratio of reactants (X3), catalyst loading (X4), duty cycle (X5), and ultrasonic power (X6). The maximum yield of fatty acid methyl esters (FAME) obtained under conditions of time of 120 min, temperature of 30°C, molar ratio of reactants as 1:15 (mol: mol), catalyst loading of 1 wt%, duty cycle of 40%, and ultrasonic power of 100 W was 99%. A quadratic mathematical model was also developed to formulate predictions about the expected yield under a set of operating conditions. The statistical analysis and analysis of variance were executed to understand the interaction of independent variables and their effect on the biodiesel yield. Intensification due to ultrasound was demonstrated based on higher yield (99%) as compared to conventional processing without ultrasound (58%). Overall, the work clearly illustrated the intensification due to ultrasound and also helped to establish the optimum conditions.

APPLICATION POTENTIAL OF RESPONSE SURFACE METHOD ON ELECTRO DISCHARGE MACHINING OF AA6061–CENOSPHERE AMCs PREPARED BY COMPOCASTING METHOD

Cenosphere fly ash particles are incorporated into AA6061 alloys with different concentrations ranging from 0[Formula: see text]wt.% to 10[Formula: see text]wt.% using a modified semi-solid metal processing technique. X-ray diffraction patterns were recorded to analyze the morphology of the aluminum-based metal matrix composites (AMCs). The major diffraction peaks of Al, SiO2, Al2O3 and Fe2O3 are distinctly identified which revealed the presence of cenosphere particles and their integrity within the matrix is preserved. The high-resolution optical micrograph identifies the homogeneous distribution and uniform dispersion of the particles. Machinability of the prepared AMCs was investigated by electro discharge machining (EDM) using response surface methodology (RSM). Face-centered CCD of RSM was considered to design the number of experimental runs required. ANOVA was used to explore the influence of selected process parameters and their interactions on the performance characteristics of the systems by developing a second-order quadratic mathematical model for all the responses. Pulse on-time and pulse current were observed to be the most influencing independent variables of EDM system that affect the selected performance measures during spark erosion process. Finally, desirability function approach was employed to optimize the parameters. The optimal processing condition was identified as follows: pulse current: 6 A, pulse on-time: 1010[Formula: see text][Formula: see text]s, percentage of reinforcement: 2% and flushing pressure: 0.2 MPa. Very small percentages of deviation have been observed while comparing with the experimental results obtained for MRR (8.6%), TWR (10.3%) and SR (2.18%).

Simultaneous Removal of Binary Mixture of Cationic Dyes onto Bombax Buonopozense Bark: Plackett–Burman and Central Composite Design

In this study, the retention of BB41 and SAF was studied using a PBD three-level screening plan, as the initial concentration of dyes, BBP mass, pH, and temperature. Pareto analysis to select the pH and the adsorbent mass as influential factors to make a CCD optimization plan, the optimization has established a quadratic mathematical model for each dye. The binary system's common optimal conditions were selected to be a BBP mass of 0.46 g/l and a pH of 8.54. Under optimal conditions, the removal efficiency of BB41 and SAF is 83.76 and 73.23%, respectively, with the desirability of 1.00, which is confirmed by a later experiment. The equilibrium adsorption data of BB41 and SAF in the mixture are well explained by the Langmuir isotherm with an adsorption capacity of 75.18 and 80.64 mg/g, respectively. A good fit of the experimental data according to the pseudo-second-order kinetic model, with a correlation coefficient R2> 0.99. Finally, Bombax buonopozense (BBP) was characterized using FTIR, SEM and elemental analysis.