Factorial Experimental Design Method Research Articles

Comprehensive investigation of surface quality and mechanical properties in CO2 laser drilling of GFRP composites

The present paper aims to study different laser drilling/cutting parameters including laser intensity, cutting speed, and gas pressure in order to achieve minimum surface roughness (Ra), heat-affected zone (HAZ), taper angle (TA), and maximum tensile strength (TS) of the laser-drilled glass fiber-reinforced plastic (GFRP) laminate. Full factorial design of experiment method and analysis of variance were adopted to investigate the effect of each parameter on the responses, and in addition, the surface roughness and tensile strength were compared with that of conventional drilling. The morphology of the laser-drilled holes was studied through the scanning electron microscopy (SEM). It was found that optimum laser drilling parameters can yield higher tensile strength and lower surface roughness in drilled GFRP laminate compared to the conventional drilling. Moreover, multi-response optimization was carried out on the results in order to obtain maximum tensile strength, minimum HAZ, minimum surface roughness, and minimum taper angle. The results revealed that the laser intensity, cutting speed, and assist gas pressure should be set at 2.04 W/cm2, 8 mm/s, and 4 bar, respectively, to obtain higher tensile strength and surface integrity. The results drawn from this study can be applied to improve the surface quality and mechanical properties of laser drilling of FRP materials especially in aircraft part manufacturing.

Design of a New N-Shape Composite Ultra-Thin Deployable Boom in the Post-Buckling Range Using Response Surface Method and Optimization

Composite ultra-thin boom can be folded elastically. Moreover, such booms are able to self-deploy by releasing stored strain energy, which can be applied in deployable antenna, solar sail, and optical telescopes. Surrogate models for imperfection-sensitive quantities of interest and multi-objective optimization are developed for the design of a new N-shape cross-section composite ultra-thin deployable boom. The proposed optimal design method integrates four general steps: (1) design of experiments, wherein the sampling designs of the N boom are created on the basis of the two-factor five-level full factorial design of experiments method; (2) efficient computational analyses of each design sample, wherein the post-buckling behavior of the N boom are analyzed under three different axial directions using nonlinear finite element ABAQUS/Explicit solver; (3) establishing the surrogate models of bending stiffness around the x-and yaxes and torsional stiffness around the z-axis by response surface method (RSM); (4) performing the multi-objective optimization design using modified non-dominated sorting genetic algorithm to realize the optimal design. The bending stiffness around the x-and yaxes and the torsional stiffness around the z-axis are set as the objectives, mass is set as the constraint, and the bonded web height and the central angle of the middle tape spring of the N boom are set as the variables. The typical surrogate modeling method can be applied to different problems in structural and material design.

The effect of conventional metal spinning parameters on the spun-part wall thickness variation

Conventional metal spinning technology is based on the sequential shaping of a circular sheet over a mandrel through the action of a roller that produces localised pressure to produce a hollow axisymmetric product. The wall thickness of the formed part in this process is, in general, considered to be nearly constant, but in fact, a non-uniform distribution of wall thickness is observed. The wall thickness variation is a major defect found in produced parts that can cause part failure and therefore the spinning process must be properly optimized. This paper deals with the analysis of the chosen conventional metal spinning parameters (tool path profile, mandrel speed and the tool feed rate) on the wall thickness variation of cylindrical shaped spun-parts made of DC01 low carbon steel, while a three-level full factorial design of experiment method (DoE) and ANOVA (Analysis of Variance) were used. The experimental results revealed that tool path profile and the tool feed affects the wall thickness variation in a significant way. The effect of the mandrel speed was not clearly observed.

Investigation of the influence of different burnishing parameters on shape correctness and residual stresses

Cold plastic procedures such as surface burnishing play an important role in life-enhancing machining methods. Application of this process the surface roughness improves, shape correctness also changes and the increases lifetime due to the compressive residual stress remains in subsurface are of the workpiece. This article deals with the change of these attributes and the correlation of these with the burnishing parameters: burnishing speed, feed rate, burnishing force and number of passes on diamond burnished low alloyed aluminium shafts. The experiments were executed by the Taguchi type full factorial experimental design method, the measurements of the cylindricity of the specimens were done with a circularity and position error machine while the measurement of residual stress was performed by X-ray diffraction method. The aim of this study is to define the appropriate range of technological parameters which result high improvements.

Impact of structural process variation on junctionless silicon nanotube FET

In this paper, the impact of process variation on the performance parameters of junctionless silicon nanotube field effect transistor (JLSiNT-FET) is studied using 3D numerical simulations. The performance metrics, ON current, OFF current, and unity gain frequency are taken for different physical factors. Sensitivity of the physical factors is computed over a range at various points. The ranking of the structural parameters for various performance metrics is done using a two level full factorial design of experiment method. Overall ranking proposes that the outer diameter of the silicon tube is the most sensitive parameter and inner diameter of the silicon tube is the least sensitive parameter.

Application of metallurgical slag to treat geothermal wastewater with high concentrations of arsenic and boron

The reuse of geothermal wastewater for irrigation is an attractive alternative for supplying water demand in agriculture, due to the high volumes generated in geothermal plants. This application is limited by the presence of toxic semimetals such as arsenic and boron, which generally require high-cost commercial adsorbents for removal. This work studies the removal mechanism and process optimization of arsenic and boron, present in high concentrations in synthetic solutions and in geothermal wastewater, using metallurgical slags. The effect of pH, initial concentration of arsenic and boron and slag dose were investigated using a 33 factorial experimental design and response surface method to optimize the operating conditions of the removal of pollutants. Scanning electron microscope analysis showed that the removal mechanism consisted in a dissolution–precipitation reaction rather than adsorption. The effluent produced from wastewater at the optimal operating conditions in a two-step process meets the criteria proposed for both metalloids by the US Environmental Protection Agency for water used for irrigation.

The effect of particle size of body components on the processing parameters of semi transparent porcelain

The effect of the particle size of quartz and K- feldspar on the sintering behaviour and technical properties of semi transparent porcelain were investigated. This study was implemented by “the Factorial Experimental Design Method” to determine the effect of factors on semi vitreous porcelain production. The sintering behaviour of the samples were examined by using an optical dilatometer. The phases and their respective amounts in the microstructure were determined by way of Rietvelt X- ray diffraction (XRD) technique. Furthermore, the values such as shrinkage, water absorption, bulk density, porosity, thermal expansion, light transmission measurements were taken on the samples and the microstructures were studied by SEM. It was observed that as the particle size of quartz and K- feldspar decreased; the viscosity of the liquid phase fell down, the relative amount of secondary mullite crystals increased and the large pores were removed among the particles and the densification rate increased. Data were analysed by Minitab 13.20 software, and assessed in relation to the amount of glassy phase and its viscosity. The effect of K- feldspar particle size on the densification of porcelain is less than the change of heat treatment and quartz particle size.

Prediction of the thickness loss and recovery of cut-pile carpets imposed to UV exposure and wear using polynomial regression method

Ultraviolet radiation which exists in environment around can be regarded as a major source of textile materials. In this study, the effect of UV exposure on the cut-pile carpet was investigated. A UV chamber was used to expose different levels of accelerated UV radiation on the samples of the machine-woven pile carpet. Wear test were then carried out on all samples using a Hexapod tumbler machine. The short-term static loading was applied to the carpets and the thickness loss percent (TL) and recovery percent (RP) of the samples at different times after load removal was measured using standard methods. Factorial experimental design and response surface method were applied for to create polynomial regression models and predict each of the thickness loss and recovery percent of carpet samples. The model is capable to determine the contribution of different variables. The results of the modeling revealed a desirable fit. The adjusted R2 values were also high and significant. The ANOVA test indicated that the presented models were valid at 5% significant level.

Optimization of Parameters Influencing Tensile Strength of Inconel-625 Welded Joints Developed Through Microwave Hybrid Heating

Processing of bulk metals through microwave energy in recent years is finding widespread applications and is being prominently accepted by the manufacturing industries. Present work, investigates the effect of process parameters on the tensile strength of Inconel-625welded joints produced through microwave hybrid heating using design of experiments. Experiments were carried out by using Taguchi’s L16 factorial design of experiment method. Input parameters chosen were separator type; susceptor type and filler powder size. The output response chosen was ultimate tensile strength. Optimization of the process parameters is done through Taguchi method and percentage influence of each process parameter on the strength of weld is determined using ANOVA method. Combination of parameters with graphite separator, SiCsusceptor and finer filler powder yields optimum result.

Analysis of the effects of fabric reinforcement parameters on the mechanical properties of textile-based hybrid composites by full factorial experimental design method

In this study, the effect of some fabric reinforcement parameters (fabric direction, yarn type and stacking sequence) on the mechanical properties of textile based hybrid composites are analysed by using full factorial experimental design method. The analysis of the results is achieved by using Minitab 17 software program. One factor (fabric reinforcement direction) with two levels (warp direction and weft direction) and two factors (yarn type and stacking sequence) with three levels (jute/glass, jute/carbon, glass/carbon and consecutive, low strength inside, high strength inside) are selected as the reinforcement design. Full factorial experimental design analysis results indicate that, the highest tensile and impact strength values among the experimental design are realised when samples are taken from the warp direction and E-glass/carbon combination is chosen as the yarn (material) type. Moreover, it is verified that while higher tensile strength is achieved by placing higher strength fabrics to the inner layers, higher impact strength is achieved by placing high strength fabrics to the outer layers of hybrid composite structures. Analysis of variance tables also show that at 95% confidence level, the effects of the factors are statistically significant ( p < 0.05).

Analysis of shape correctness of surfaces of diamond burnished components

In these days, diamond burnishing is frequently used for final finishing manufacturing operations of components. Diamond burnishing belongs to cold plastic manufacturing procedures. When using this technique, the following advantages can be obtained: micro-hardness of near surface layer is increasing; surface roughness is improving and the shape correctness is also improving. This paper deals with how the different technological parameters of burnishing, such as the feed rate, the burnishing speed and the burnishing force effect on the cylindricity of the burnished workpiece. The experiment was done on some specimen having outer cylindrical surfaces. The experiments were executed by the Taguchi type Full Factorial Experiment Design method with which empirical formulas can be efficiently created. The measurements of the cylindricity of specimens were done with a circular and position error measuring. From the measured data, special improvement ratios were calculated in order to define the appropriate range of technological parameters which results high improvements. Further aim was to compare the measured values of different cylindricity parameters.

Methylene Blue and Brilliant Green Dyes Removal from Aqueous Solution Using Agricultural Wastes Activated Carbon

This paper investigated the analyses of removal of Methylene Blue (MB) and Brilliant Green (BG) dyes from aqueous solutions by adsorption on activated carbon prepared by chemical activation of coconut shell, eucalyptus tree, corn cob and flamboyant pod. It was found that the carbon pores increased after carbonization and activation processes. The maximum percentage MB removal was obtained as 95.0% for coconut shell, 93.2% for eucalyptus tree, 99.9% for corn cob, and 99.7% for flamboyant pod. Also, the maximum percentage BG removal was obtained as 97.0% for coconut shell, 98.2% for eucalyptus tree, 99.6% for corn cob, and 99.6% for flamboyant pod. The adsorption isotherms of the adsorption process were studied, and Freundlich model showed the best fit with the equilibrium data. To optimize the operating conditions, the effects of contact time, adsorbent dosage, and pH were investigated by two levels of factorial experimental design method and adsorbent dosage was found as the most significant factor.

Statistical Analysis of Coal Beneficiation Performance in a Continuous Air Dense Medium Fluidized Bed Separator

ABSTRACTIn this study, the performance of a continuous air dense medium fluidized bed (ADMFB) separator is investigated for coal beneficiation. The full factorial experimental design method is used to study the effect of superficial air velocity (U), bed length (T), and bed height (H) on the clean-coal ash content, organic material recovery, and overall system separation efficiency. Optimum operating conditions are determined and followed by the effect of feed particle size on separation quality. Statistical analysis of the results revealed that H had no significant effect on product ash content while U and T had negative effects. A reduction in ash content from 19% to 10% was obtained once full bed length was utilized. The increase of all parameters had a negative effect on organic material recovery, while recovery was always above 88%. The only significant mutual interaction was found to be between T and H with even more effectiveness than U on the recovery. Separation efficiency increased by increasing the bed length and reached 20% once full bed length was utilized. The optimum operating condition was determined to be at U = 19.5 cm/s, T = full bed length, and H = 15 cm. It was observed that feeding finer particles deteriorated the beneficiation process.

Enhanced Production of Insulin-like Growth Factor I Protein in Escherichia coli by Optimization of Five Key Factors.

Human insulin-like growth factor I (hIGF-I) is a kind of growth factor with clinical significance in medicine. Up to now, E. coli expression system has been widely used as a host to produce rhIGF-1 with high yields. Batch cultures as non-continuous fermentations were carried out to overproduce rhIGF-I in E. coli. The major objective of this study is over- production of recombinant human insulin-like growth factor I (rhIGF-I) through a developed process by recruiting effective factors in order to achieve the most recombinant protein. In this study we investigated the effect of culture medium, induction temperature and amount of inducer on cell growth and IGF-1 production. Taguchi design of experiments (DOE) method was used as the statistical method. Analysis of experimental data showed that maximum production of rhIGF-I was occurred in 32y culture medium at 32 °C and 0.05 Mm IPTG. Under this condition, 0.694 g/L of rhIGF-I was produced as the inclusion bodies. Following optimization of these three factors, we have also optimized the amount of glucose and induction time in 5 liter top bench bioreactor. Full factorial design of experiment method was used for these two factors as the statistical method. 10 g/L and OD600=5 were selected as the optimum point of Glucose amount and induction time, respectively. Finally, we reached to a concentration of 1.26 g/L rhIGF-1 at optimum condition.

Factorial experimental design for Remazol Yellow dye sorption using apple pulp/apple pulp carbon–titanium dioxide co-sorbent

Dye containing effluents can cause severe organic and color pollution in the water environment, thus removal of reactive dyes by sorption is an important circumstance. The aim of this study was to identify the operating conditions which influence Remazol Yellow dye sorption from aqueous solutions. There are limited numbers of literature studies about Remazol Yellow dye sorption. Despite that the sorption of Remazol Yellow dye by co-sorbent system and optimization of such process have not yet been studied. Thus, apple pulp and carbonized apple pulp at 550 °C were used as sorbents, also apple pulp–titanium dioxide and apple pulp carbon–titanium dioxide mixtures were used as co-sorbents. Elemental analysis, X-ray fluorescence spectroscopy, scanning electron microscopy, zeta potential, particle size distribution, and Fourier transform infrared spectroscopy analysis were conducted to analyze apple pulp and apple pulp carbon. The effects of pH, initial dye concentration and contact time were investigated by 33 full factorial experimental design method and analysis of variance statistical approach to optimize the operating conditions. The maximum percentage dye removal was obtained as 86.97% (sorbent type = apple pulp–titanium dioxide, pH = 2, initial dye concentration = 10 mg/L and contact time = 120 min). pH, initial dye concentration and contact time were found as significant within a 95% confidence level for all type of sorbents. Equilibrium isotherm data were fitted to Langmuir and Freundlich equations and the Langmuir model showed the best fit with equilibrium isotherm data. Furthermore, pseudo-first and second-order kinetic models were also used to analyze sorption kinetics. Since apple pulp was low-cost and easily available material, and also application of co-sorbent was influential for dye sorption; it could be successfully applied for the removal of Remazol Yellow dye from aqueous solutions.

Multiple Regression Analysis of Catalytic Dehydrogenation of Isopropanol in a Chemical Heat Pump System

AbstractChemical heat pump is a clean technology developed to upgrade the low‐level thermal energy to upper levels and to store energy without losses caused by temperature differences. Multiple regression analysis of catalytic dehydrogenation of isopropanol was performed. The endothermic dehydrogenation of isopropanol was carried out under continuous boiling and refluxing conditions in order to study the enhancement effects of the presence of an alkaline compound and different types of catalysts at various concentrations in the reaction medium on the evolution rate of hydrogen. The factorial experimental design method was applied to understand better the coupled influences of both catalyst and alkaline additive concentrations to discuss and evaluate statistically the results for different catalysts and to develop the related models.

Effect of parameters on vanadium recovery from by-products of the Bayer process

Leach solutions and wastes of the Bayer process are important resources for metals such as aluminum and vanadium. Despite the fact that vanadium is precipitated as cake and removed in the Seydisehir Eti Aluminum Facility (Turkey), it cannot be used due to low metal content and impurities it contains. Within the scope of this study, research and development of environmentally acceptable, technically sound and low-cost chemical leaching and recovery methods were conducted for the recovery of vanadium from the by-product cake of the Bayer process. In the conducted studies, a sample of vanadium cake was used after its detailed characterization. Roasting tests were performed in order to remove the arsenic from the vanadium cake; however, it was found that roasting was not effective for arsenic removal. The performances of different reagents were examined in chemical leaching tests (H2O and H2SO4 leaching, H2SO4 leaching with the addition of NaSO3, and NH4F); in the H2SO4 leaching tests performed with the addition of Na2SO3, the effects of concentrations of reagents and temperature on the efficiency of vanadium recovery (max. 93.09%) were determined with the full factorial experimental design method. The results were evaluated with ANOVA (variance analysis) method, and empirical models were formed. In lab and semi-pilot scale leaching tests, vanadium recoveries were 96.34% and 94.76% respectively. Vanadium was precipitated with NaOH and FeSO4 and almost all vanadium (95.8%) was obtained as Fe3(VO4)2. Cost analysis and economic evaluation have shown the economic feasibility of the leaching and recovery processes proposed.

Optimization of the Dissolution of Tincal Ore in Phosphoric Acid Solutions at High Temperatures

The aim of the study was to investigate the optimization of the dissolution of tincal ore in phosphoric acid solutions at high temperatures in a batch reactor. The effect of the following parameters on the dissolution process was investigated: the reaction temperature, the phosphoric acid concentration, the particle size, and the solid-to-liquid ratio. The best conditions for the dissolution were determined using the 24 factorial experimental design method. The optimum values of the parameters were experimentally determined. The effective parameters were the reaction temperature, the phosphoric acid concentration, the particle size, and the solid-to-liquid ratio. The optimum conditions resulted in the maximum boron dissolution at an acid concentration of 1 M, reaction temperature of 85°C, particle size of 4.75 mesh, and solid-to-liquid ratio of 1/6 g · mL−1. Under these optimum conditions, the best dissolution yield was 98.26%.

The effects of synthesis operation conditions on the properties of modified γ-alumina nanocatalysts in methanol dehydration to dimethyl ether using factorial experimental design

The catalytic performance of a series of γ-Al2O3 nanocatalysts prepared by precipitation method and modified with various amounts of silica (0–15wt.%) were studied in dehydration of methanol to dimethyl ether. The nanocatalysts were characterized by TGA, ICP, BET, XRD, FE-SEM and NH3–TPD techniques. The screening and performance tests were carried out in an isothermal fixed-bed reactor at 300°C, 16atm and LHSV of 15.6mL/(hgcat). It was found that the γ-Al2O3 nanocatalyst containing 2wt.% of SiO2 exhibits the highest activity among the modified ones. The number of acidic sites of the modified nanocatalysts was increased by the silica modification up to 2wt.% of SiO2 and afterward decreased. The effects of five preparation parameters including precipitation/aging temperature (50,80°C), aging time (2,6h), pH of precipitation step (6.5,7.5), mixing rate (300,600rpm) and the type of precipitant (NaOH,NH4HCO3) on surface area, particle size, number of acidic sites and catalytic performance were investigated using 2(5−1) fractional factorial experimental design method. The main effects of pH, precipitant agent and mixing rate were concluded to be the key factors influencing the catalytic activity and physico-chemical properties of nanocatalysts. The optimum conditions for preparation of 2wt.% SiO2-modified γ-Al2O3 nanocatalyst with maximum yield of dimethyl ether were obtained as T(pre./aging)=50°C, t(aging)=2h, pH(pre.)=7.5, mixing rate=600rpm and precipitant agent=NH4HCO3. The sample prepared under optimized conditions showed a favorable surface area of 251.5m2g−1, pure γ-alumina crystallite phase and a methanol conversion of 78.2%.

Modeling the functional compression properties of hand-knotted carpets using factorial design and response surface methodology

The most performance quality of cut-pile carpets is related to mechanical behavior of surface piles under compression loading in use. In this study, main purpose was to achieve the predictive models of the functional compression properties of carpet including work of compression (WC), compressional resilience (RC), linearity of compression-thickness curve (LC), and thickness loss (TL) after recovery on hand-knotted carpets with symmetric (Turkish) knot. Eighteen hand-knotted carpet samples with different structural specifications were produced. Meanwhile, compression properties were investigated in new and worn out carpet samples by a Hexapod tumbler tester in 4000 and 12000 revolutions. Factorial experimental design and response surface method were applied for modeling of each compression properties. To optimize the initial models the Box-Cox transformation was used. In the final models, contribution of different variables was also determined. The models showed a desirable fit and high adjusted R2 values were observed. The ANOVA test showed that the obtained models are valid at 5 % level significant.