Taguchi Experimental Design Approach Research Articles

Toward Impedimetric Measurement of Acidosis with a pH-Responsive Hydrogel Sensor.

A pH-responsive, poly(2-hydroxyethyl methacrylate) [poly(HEMA)]-based hydrogel has been fashioned into an impedimetric pH sensor for the continual measurement and monitoring of tissue acidosis that can arise due to hemorrhaging trauma. Four hydrogel systems molecularly engineered to influence water distribution and ionic abundance were studied: a cationogenic primary amine, N-(2-aminoethyl) methacrylate (AEMA), a tertiary amine moiety, N,N-(2-dimethylamino)ethyl methacrylate (DMAEMA), and a combined AEMA-DMAEMA formulation. Electrochemical impedance spectroscopy (EIS) of hydrogel discs held between platinized Type 304 stainless steel mesh electrodes in pH-adjusted 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid sodium salt (HEPES) buffer and equivalent circuit modeling indicated that the AEMA hydrogel had the highest sensitivity containing the relevant pathophysiological range (pH 7.0-8.0). Thus, the AEMA formulation was studied at 0, 1, 3, 4.4, and 30 mol % AEMA. The 1 mol % AEMA was found to significantly (p < 0.05) discern nominal pH (7.35, 7.40, 7.45). The Taguchi Design of Experiments approach was employed and confirmed composition as a factor and 1 mol % AEMA to be the most robust. DMAEMA (0, 4.4, 14, 30 mol %) and AEMA-DMAEMA (0, 4.4, 14, 30 mol %) allowed the use of the one-factor Response Surface Methodology optimizer to confirm the AEMA 1 mol % system to be most robust, sensitive, and possessing optimal sensitivity in the pathophysiological pH sensing range (7.35-7.45) for hemorrhagic trauma. This composition was fashioned as a responsive membrane on a microlithographically fabricated interdigitated microsensor electrode and the sensitivity was determined using R(QR)(QR) analysis. Water distribution within the AEMA (0, 1, 4.4, 30 mol %), determined by gravimetric analysis and differential scanning calorimetry, revealed a strong anticorrelation between nonfreezable bound water and pH sensitivity (-0.82) and was in good agreement with the total hydration (-0.70). Nonfreezable bound water was found to be the most strongly correlated factor that governs the pH response of hydrogels.

Experimental investigations into magnetic abrasive flow finishing process on aluminium 6061-T6

The magnetic abrasive flow finishing (MAFF) process has been developed and investigated as an advanced fine finishing process. It is used for a surface finish (SF) of the straight and complex intricate profile using the ferromagnetic nature of abrasive media. This article presents an experimental investigation on the newly developed MAFF attachment, which was mounted on a shaper machine. A custom design workpiece fixture was used in MAFF attachment for the finishing of a straight hollow cylinder shape workpiece, which can easily modify based on workpiece shapes. A curved workpiece seat was prepared and fasting with two brass plates by nut and bolts arrangement. Taguchi design of experiment approach applied for experimentation on aluminium 6061-T6 workpiece material by MAFF setup. The main process parameters considered for experimentation are magnetic flux density (MFD), number of cycles, abrasive concentration, and piston speed while responses are material removal (MR) and surface finish (SF). The results found after finishing by MAFF were also compared with the AFF. It was identified that remarkable enhancements observed in MAFF responses. The finished surfaces were also observed by scanning electron microscope (SEM) and X-ray diffraction (X-RD).

Novel modifications of social engineering optimizer to solve a truck scheduling problem in a cross-docking system

The truck scheduling problem is one of the most challenging and important types of scheduling with a large number of real-world applications in the area of logistics and cross-docking systems. This problem is formulated to find an optimal condition for both receiving and shipping trucks sequences. Due to the difficulty of the practicality of the truck scheduling problem for large-scale cases, the literature has shown that there is a chance, even with low possibility, for a new optimizer to outperform existing algorithms for this optimization problem. Already applied successfully to solve similar complicated optimization problems, the Social Engineering Optimizer (SEO) inspired by social engineering phenomena, has been never applied to the truck scheduling problem. This motivates us to develop a set of novel modifications of the recently-developed SEO. To validate these optimizers, they are evaluated by solving a set of standard benchmark functions. All the algorithms have been calibrated by the Taguchi experimental design approach to further enhance their optimization performance. In addition to some benchmarks of truck scheduling, a real case study to prove the proposed problem is utilized to show the high-efficiency of the developed optimizers in a real situation. The results indicate that the proposed modifications of SEO considerably outperform the state of the art algorithms and provide very competitive results.

Epoxy adhesives toughened with waste tire powder, nanoclay, and phenolic resin for metal-polymer lap-joint applications

Brittleness and low thermal stability of epoxy confines its usage as adhesive for metal-polymer interfaces. In this work, epoxy formulations containing phenolic resin (X1 (wt.%), for thermal stability), recycled tire powder (X2 (wt.%), economically reasonable for toughening), and clay nanoplatelets (X3 (wt.%), for modulus enhancement) were optimized based on L9 Taguchi experimental design approach. The main effects of X1, X2, and X3 on mechanical properties of epoxy adhesives including tensile strength, Young’s modulus, and toughness, were studied by taking into account signal-to-noise ratio (S/N) as well as the analysis of variance (ANOVA). It was found that at X1 level of 50 wt.%, X2 level of 10 wt.%, and X3 level of 2 wt.% an increase of about 39% was observed in the single-lap shear strength compared to blank epoxy adhesive formulation. Scanning electron microscopy revealed crack mechanism in the form of deviation of crack growth pathway when encountered with large platy nanoclays. Thermal stability of epoxy was also improved by 16% based on degradation peak temperature monitoring.

Adsorptive removal of Bisphenol A by biomass activated carbon and insights into the adsorption mechanism through density functional theory calculations

Activated carbon was synthesized from Tithonia diversifolia biomass using potassium hydroxide as the chemical activating reagent. Taguchi's experimental design approach was applied to determine the best preparation conditions. An optimum 2:1 impregnation ratio and 700 °C activation temperature produced the best carbon with a high 854.44 m2g-1 surface area, 0.445 cm3g-1 total pore volume and 18.3% yield. From the analysis of variance (ANOVA), the impregnation ratio was found to be the most influential factor in preparing activated carbon with the maximum surface area. SEM and XRD studies revealed the porous microcrystallite structure of the obtained activated carbon. Batch adsorption studies were performed to test the efficiency of Tithonia diversifolia activated carbon for the removal of Bisphenol A (BPA) from aqueous solution. A maximum 98.2% removal percentage was attained at optimum conditions of 0.2 g adsorbent dose, pH 7, 80 min contact time and 40 mg L−1 initial BPA concentration. The Langmuir isotherm model described the equilibrium adsorption of BPA well with a maximum adsorption capacity(qm) of 15.69 mg g−1 while the kinetic adsorption study indicated a pseudo second order model. A theoretical investigation suggested that the adsorption of BPA onto the activated carbon mainly proceeds via chemisorption and the presence of a carboxyl functional group on the activated carbon surface yielded a greater adsorptive impact on BPA. This study indicates that Tithonia diversifolia could be used as a potential raw material for preparing activated carbon for removing of BPA from water.

Effects of Leaching Parameters on the Impurity Ion Concentrations at Ulexite Ore Leaching: An Experimental Design Approach

An experimental study was conducted to determine the effects of the leaching parameters on impurity ion concentrations of the liquid phase in ulexite leaching. Powdered ulexite ore was leached in an aqueous medium with sulfur dioxide. The Taguchi experimental design approach and statistical methods were used to evaluate the effects of the leaching parameters (solid/liquid ratio, temperature, pH, particle size, time) on impurity ion concentrations (concentrations of magnesium, calcium, iron ions) in the liquid phase. The average B2O3 leaching ratio of ulexite ore was found as 98.56 % (± 0.95). Statistically effective leaching parameters on impurity concentrations (and delta values for concentrations) were found as pH (770 ppm) for magnesium, solid/liquid ratio (372 ppm) for calcium ion concentrations. The examined parameters were not found effective for iron ion concentrations.

An experimental investigation of nanoemulsion enhanced oil recovery: Use of unconsolidated porous systems

Utilization of nanoparticles in oil and gas industry has attracted considerable attention of engineers and researchers. In this article, the feasibility of nanoemulsion flooding is investigated as a method for Enhanced Oil Recovery (EOR) through coreflooding experiments, using a packed bed and real reservoir fluids. Nine different mixtures of the solvent, surfactant, and nanoparticles in the form of a nanoemulsion phase are generated and used to recover the oil in the context of an EOR process. Various tests are conducted to determine the properties of porous medium and fluids. To study the production performance of this EOR technique, pressure drop across the packed bed are measured, along with the volumetric measurements of the produced fluids. A baseline injection scheme using seawater is also performed. All the nanoemulsion fluids are synthesized using the same base seawater. The Taguchi experimental design approach is employed in this research to design the experiments. The effects of nanoparticles concentration, along with those of surfactant and solvent components of the injection fluid on the oil recovery at the laboratory scale are investigated using the Analysis of Variance (ANOVA) method. Comparing the performance of waterflooding (WF) and nanoemulsion flooding, enhancement in the Recovery Factor (RF) by using emulsions is between 40–107%. Both the pressure and pressure fluctuations are surprisingly higher in the case of WF in comparison to the emulsion flooding. It is also found that under optimal concentration conditions (0.01 g of nanoparticles, 0.015 mL of surfactant, and 1 mL of solvent per one liter of brine), a recovery factor of up to 60% is achieved.

Parametric optimization of resistance spot welding for multi spot welded lap shear specimen to predict weld strength

Abstract This paper examining the impact of welding parameters, by parametric investigation of multi spot welded lap shear specimen, on the tensile shear strength of spot welded specimen. Further, study is carried out, to develop mathematical model by using regression analysis which shows relationship between selected welding parameters and weld strength. The design parameters considered are specimen thickness, number of spots and distance between the spots while process parameters are electrode force and weld current. As per Taguchi design of experiment approach, five welding parameters with three levels of each are considered for analysis. Experimentation is carried out as per L27 orthogonal array to investigate the effect of process and design parameters on tensile shear strength. Particle swarm optimization (PSO) method was used to determine welding parameter has a significant impact on weld strength. Tests for confirmation have been conducted to validate the results. Confirmation tests exhibit that deviation between the results obtained by experimentation and regression is up to 0.571741%. Particle swarm optimization explore that maximum tensile shear strength 9399.55 N is obtained at 06 numbers of spot and 16 mm distance between the spots as optimum value for 1.22 mm galvanized steel sheets.

Study of the electrophoretic deposition copper–carbon nanotubes composite coatings in deep eutectic solvent using a Taguchi experimental design approach

ABSTRACTThe present work discusses the electrophoretic deposition (EPD) of copper–carbon nanotubes (Cu–CNTs) composite coatings in a Deep Eutectic Solvent (DES) media, using a non-symmetric deposition process. A Taguchi experimental design is implemented in order to assess the effect of the different parameters on the microstructural characteristics of the coatings. The analysis of the design of experiments (DOE) is performed with the signal to noise (S/N) ratio and the analysis of variance. The results clearly reveal that the time of deposition is the most influential parameter on crystallite size, whereas the asymmetric factor has the highest effect on the preferential deposition of Cu or C and thus on the chemical composition. It is therefore concluded that by changing some of the parameters, EPD can be implemented to develop nanostructured composite coating having a desired crystallite size and morphology.

Optimizing the Preparation Conditions of Silica Supported Fe-Co-Ce Ternary Catalyst for the Fixed-bed Fischer-Tropsch Synthesis: Taguchi Experimental Design Approach

Using wet impregnation method, a novel ternary system of silica supported Fe-Co-Ce catalyst was prepared. Preparation conditions such as impregnation time and temperature, drying time and temperature, were optimized by the L9 Taguchi experimental design to achieve a light olefin selective catalyst with maximum CO conversion in a fixed bed micro-reactor. It was found that the best conditions to maximize the responses were obtained at 4h impregnation time, 60°C impregnation temperature, 6h drying time, 90°C drying temperature and 350°C of reaction’s temperature. Characterization of the optimal catalyst precursors and calcined samples before, and after the Fischer-Tropsch reaction was carried out using various techniques.

Optimization of activated carbon production from sunflower seed extracted meal: Taguchi design of experiment approach and analysis of variance

Abstract Taguchi method has been applied to design optimal activation conditions in the production of activated carbon with high specific surface area using sunflower seed extracted meal through chemical activation using either zinc chloride or phosphoric acid. The activation temperature and the impregnation ratio were selected as the factors of the activation process to be optimized. The activated carbons were prepared according to the L9 orthogonal array. Brunauer-Emmett-Teller surface area of the activated carbons was calculated by using nitrogen adsorption data obtained at −196 °C. The optimum level of the activation temperature for preparing the activated carbon with a high surface area was 600 °C for both chemical agents. The optimal levels of the impregnation ratio for a high specific surface area were determined as 3:1 and 2:1 for zinc chloride and phosphoric acid, respectively. The results of this study showed that the activation temperature is the most significant factor to get activated carbons with higher specific surface area. Taguchi method also allows a more detailed and accurate assessment to prepare the activated carbon in a cleaner way.

A statistical approach towards processing optimization of ZrB2–SiC–graphite nanocomposites. Part I: Relative density

The influence of sintering variables and nano-graphite addition on the densification behavior of ZrB2–SiC based ceramics has been investigated. The ZrB2 matrices, reinforced with 25 vol% submicron SiC particles and 0–10 wt% graphite nano-flakes, were fabricated by spark plasma sintering (SPS). The Taguchi design of experiment approach was employed to study the effects of SPS variables (temperature, dwell time, and pressure) and nano-graphite content. Statistical analysis of variance identified the SPS temperature and graphite content as the most influential parameters affecting the relative density of as-sintered ceramics, whereas the SPS pressure did not have an obvious impact on the densification process. The thermodynamical and microstructural analyses showed that the addition of graphite nano-flakes led to the removal of the thin oxide layers from the surfaces of the non-oxide starting materials. The elimination of such harmful oxides and the in-situ formation of nano-sized ZrC and B4C phases resulted in the enhancement of sinterability of ZrB2–SiC–graphite nanocomposites. A fully dense sample was achieved at optimal processing conditions; i.e. by sintering at 1900 °C for 7 min under 40 MPa and adding 5 wt% graphite nano-flakes.

Taguchi Design of Experiments Approach to Determine Process Parameter for the Electrophoretic Deposition of Chitosan/Bioactive Glass on Mg Alloy Substrates

Bioactive glass/chitosan composite coatings were successfully deposited on a Mg alloy (WE43) by electrophoretic deposition (EPD). A Taguchi Design of Experiments approach was employed to optimize the deposition parameters (time and voltage) and the roughness of the sample, which influence the final morphology of the coating. The surface coverage was taken as target function and evaluated with a point counting method. The optimized parameters fulfil the prediction; however, a second coating layer is still needed due to the corrosive nature of the magnesium substrate. This second layer is needed to close all pores, giving a defect free coating surface.

Electrodegradation of 2,4-dichlorophenoxyacetic acid herbicide from aqueous solution using three-dimensional electrode reactor with G/β-PbO2anode: Taguchi optimization and degradation mechanism determination

This study aimed to investigate the electro-degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution using two and three-dimensional electrode (2D and 3D) reactors with graphite(G)/β-PbO2 anode. To increase the degradation efficiency, affecting parameters on the electro-degradation process were investigated and optimized by adopting the Taguchi design of experiments approach. The structure, morphology and electrochemical properties of the electrodes were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), linear sweep voltammetry and cyclic voltammograms. The controllable factors, i.e., electrolysis time, 2,4-D initial concentration, solution pH and current density (j) were optimized. Under optimum conditions, the 2,4-D degradation efficiency was 75.6% using 2D and 93.5% using 3D electrode processes. The percentage contribution of each controllable factor was also determined. The pH of the solution was identified as the most influential factor, and its percentage contribution value was up to 39.9% and 40.4% for 2D and 3D electrode processes, respectively. Considering the parameters of the kinetics, it was found that the degradation of 2,4-D and removal of COD using the G/β-PbO2 electrode obey the pseudo-first order kinetics. In addition, the mineralization pathway of 2,4-D at G/β-PbO2 electrode was proposed. The results also demonstrated that the 3D electrode process with G/β-PbO2 anode can be considered as a useful method for degradation and mineralization of 2,4-D herbicides from aqueous solution.

Micromechanical assessment of PMMA microcapsules containing epoxy and mercaptan as self-healing agents

Mechanical properties of microcapsule shell have great influence on microcapsule suitability as a mechanical trigger in a self-healing composite. The elastic modulus and hardness of polymethyl methacrylate (PMMA) microcapsules containing epoxy prepolymer (EC 157) and pentaerythritol tetrakis (3-mercaptopropionate) (PETMP) as healing agents were investigated using nanoindentation technique. The influence of the PMMA average molecular weight (MW), the kind of core material, and the mechanical mixing rate on the mechanical properties of the microcapsule shell were studied using the Taguchi experimental design approach. The results indicated that the most important factors which affect the elastic modulus and the hardness of microcapsules shell are the Mw of PMMA and the kind of core material. The average elastic modulus of PMMA shell of epoxy and mercaptan-loaded microcapsules was found between 2.386 and 3.495 GPa. The hardness of PMMA shell of healing agent microcapsules was obtained in the range of 0.064–0.219 GPa. This constitutes essential knowledge in order to design capsules with tailored properties for self-healing materials.

A Taguchi Design of Experiment Approach to Pulse and Lock in Thermography, Applied to CFRP Composites

The current text presents a parametric study of two active thermography routines namely, Pulse and Lock-in as applied to carbon fiber reinforced plastics (CFRP) composites; using a Taguchi design of experiment approach. A set of controllable factors are highlighted and selected for each technique at different levels. Three factors have been identified for the pulse thermography (specifically; defect aspect ratio, pulse period, and experimental duration), and two factors for the Lock-in mode (that is lock in frequency and period); each factor can be manipulated at three different levels. The analysis reveals the effectiveness of the Taguchi design of experiment in consolidating the number of factorial experiments, and in quantifying the results and the associated sensitivity for each factor (its dominance), using a signal to noise ratio criterion. The analysis of variance and analysis of means show that the aspect ratio is not a controlling parameter for the pulse thermography, with the pulse time being the most dominant. Moreover, it decides on the optimal settings for each testing mode. These settings are further validated using additional CFRP artificial sample with eight and six layers of laminates.

Application of Taguchi L16 design method for comparative study of ability of 3A zeolite in removal of Rhodamine B and Malachite green from environmental water samples

This study aimed to investigate the efficiency of 3A zeolite as a novel adsorbent for removal of Rhodamine B and Malachite green dyes from water samples. To increase the removal efficiency, effecting parameters on adsorption process were investigated and optimized by adopting Taguchi design of experiments approach. The percentage contribution of each parameter on the removal of Rhodamine B and Malachite green dyes determined using ANOVA and showed that the most effective parameters in removal of RhB and MG by 3A zeolite are initial concentration of dye and pH, respectively. Under optimized condition, the amount predicted by Taguchi design method and the value obtained experimentally, showed good closeness (more than 94.86%). Good adsorption efficiency obtained for proposed methods indicates that, the 3A zeolite is capable to remove the significant amounts of Rhodamine B and Malachite green from environmental water samples.

Impacts of environmental factors on arsenate biotransformation and release in Microcystis aeruginosa using the Taguchi experimental design approach

Very limited information is available on how and to what extent environmental factors influence arsenic (As) biotransformation and release in freshwater algae. These factors include concentrations of arsenate (As(V)), dissolved inorganic nitrogen (N), phosphate (P), and ambient pH. This study conducted a series of experiments using Taguchi methods to determine optimum conditions for As biotransformation. We assessed principal effective factors of As(V), N, P, and pH and determined that As biotransformation and release actuate at 10.0 μM As(V) in dead alga cells, the As efflux ratio and organic As efflux content actuate at 1.0 mg/L P, algal growth and intracellular arsenite (As(III)) content actuate at 10.0 mg/L N, and the total sum of As(III) efflux from dead alga cells actuates at a pH level of 10. Moreover, N is the critical component for As(V) biotransformation in M. aeruginosa, specifically for As(III) transformation, because N can accelerate algal growth, subsequently improving As(III) accumulation and its efflux, which results in an As(V) to As(III) reduction. Furthermore, low P concentrations in combination with high N concentrations promote As accumulation. Following As(V), P was the primary impacting factor for As accumulation. In addition, small amounts of As accumulation under low concentrations of As and high P were securely stored in living algal cells and were easily released after cell death. Results from this study will help to assess practical applications and the overall control of key environmental factors, particularly those associated with algal bioremediation in As polluted water.

Parametric optimization of the processing of all-cellulose composite laminae

Single-polymer composites based on cellulose I and/or II (aka all-cellulose composites) are emerging as a class of high-performance bio-based composite materials with mechanical properties suited to structural applications. There are various synthesis routes for the preparation of all-cellulose composites. However, little has been reported on the optimization of the processing variables affecting the properties of all-cellulose composites. In the present work, a range of all-cellulose composites were produced as single laminae via solvent infusion processing using a precursor of cellulose II fibers that were assembled as a woven 2D textile. The effects of dissolution time, dissolution temperature, and compaction pressure during hot pressing on the properties of the laminae were then systematically examined using a Taguchi design of experiment approach in order to identify the critical control factors. The tensile properties, fiber volume fraction, and crystallinity of the laminae were determined. Statistical analysis of variance and the signal-to-noise ratio were used to rank the importance of key control factors.

Abrasive wear response of TIG-melted TiC composite coating: Taguchi approach

In this study, Taguchi design of experiment approach has been applied to assess wear behaviour of TiC composite coatings deposited on AISI 4340 steel substrates by novel powder preplacement and TIG torch melting processes. To study the abrasive wear behaviour of these coatings against alumina ball at 600° C, a Taguchi’s orthogonal array is used to acquire the wear test data for determining optimal parameters that lead to the minimization of wear rate. Composite coatings are developed based on Taguchi’s L-16 orthogonal array experiment with three process parameters (welding current, welding speed, welding voltage and shielding gas flow rate) at four levels. In this technique, mean response and signal-to-noise ratio are used to evaluate the influence of the TIG process parameters on the wear rate performance of the composite coated surfaces. The results reveal that welding voltage is the most significant control parameter for minimizing wear rate while the current presents the least contribution to the wear rate reduction. The study also shows the best optimal condition has been arrived at A3 (90 A), B4 (2.5 mm/s), C3 (30 V) and D3 (20 L/min), which gives minimum wear rate in TiC embedded coatings. Finally, a confirmatory experiment has been conducted to verify the optimized result and shows that the error between the predicted values and the experimental observation at the optimal condition lies within the limit of 4.7 %. Thus, the validity of the optimum condition for the coatings is established.