Multi-response Method Research Articles

Experimental investigation on the machining performance of AISI D2 tool steel during ultrasonic-assisted turning under dry and MQL conditions

Ultrasonic-assisted turning (UAT) is a hybrid machining method that improves difficult-to-cut materials’ machinability and surface integrity. Minimum quantity lubrication (MQL) is a cooling condition employed in metal cutting operations to improve machining performance and environmental sustainability. This article presents the experimental investigations on the effect of machining and vibration parameters and cooling conditions on the surface roughness (Ra), flank wear (Vb), and surface hardness (HV) during UAT of AISI D2 tool steel. Experiments were designed based on L36 orthogonal array. Two levels of spindle speeds, feed rates, depth of cut, and three levels of percentage intensity of ultrasonic power (PIUP) were employed, and two cooling conditions, like dry and MQL. Analysis of variance (ANOVA) was used to find the significant input parameters that affect each response. ANOVA output revealed that feed rate was the most influential factor on Ra, the PUIP is the dominant factor on HV, and spindle speed is the significant factor on Vb. Optimisation is performed to find optimal parameters as per Taguchi multi-response method. The optimal parameters are 450 rpm spindle speed, 0.05 mm/rev feed rate, 0.1 mm depth of cut, 100 PIUP and MQL cooling resulted in minimum surface roughness of 0.439 μm, maximum hardness of 283 HV and minimum flank wear of 168 μm. Flank wear morphology results showed that abrasion and chipping are the tool wear mechanism in dry UAT, whereas minor abrasion alone was found in MQL UAT compared to CT. Chip morphology study showed that UAT produced continuous spiral-type chips under both cooling conditions compared to CT. A novel design approach is implemented to design the UAT tool. Along with the UAT tool, MQL is also given to improve the machinability of D2 tool steel. This UAT tool can machine intricate metals with a critical cutting velocity of less than 75.4 m/min.

Effect of process parameters of mechanical studies on friction stir welded AA5083 by GRA

This study relates about the mechanical properties, contour analysis and multi response method was implemented into the processed similar joint of AA5083 by friction stir welding (FSW). The processing was carried with fluted cylinder tool pin profile with applicable process parameters namely; tool traverse speed (35 to 65 mm/min), spinning speed (1250 to 1750 rpm) and tilt angle (1.5 to 2.50), respectively. These parameters are mingled together with Taguchi L9 array to reframe the parameters to identify the optimal by grey analysis technique. The hardness and tensile properties were employed with whole nine welded samples. The entire samples procured fine mechanical strength due to the influence of FSW parameters resulting in more plastic deformation was occurred in the stirred region. From the GRG responses the optimal FSW parameters are 50 mm/min of traverse speed, 1500 rpm of spinning speed and 2.5 of tilt angle. The hardness and tensile strength was attained more in those particular process parameters. Influence of tool traverse and spinning speed as major impact to improve their properties.

Optimization of core-shell capsules properties (Olive oil/alginate) obtained by dripping coextrusion process

Dripping coextrusion technology was used to produce core-shell capsules (olive oil/alginate). Mathematical models were developed to study isolated, and interactions impacts of calcium chloride concentration (37.5–187.5 g. L−1), alginate and oil total feed rate (40–108 g.min−1), and dripping height (7–15 cm) on capsules characteristics. Therefore, capsules diameter, sphericity, rupture strength, and encapsulation payload were studied with response surface method using Doehlert matrix. A study showed that capsules characteristics were mainly impacted by calcium chloride concentration and alginate/oil total feed rate. The role of calcium ions on shell structuration mechanisms was highlighted. The process was successfully optimized using multi-response method through desirability function. A mathematical model was developed for the prediction of diameter, sphericity, rupture strength, and encapsulation payload of capsules produced by dripping coextrusion. This model will be useful for further process applications such as fish-egg-like capsules in food industries and “liquid pearls” in cosmetic industries.

Study and optimization of core-shell capsules produced by annular jet breaking coextrusion

Oil-alginate capsules were produced by annular jet breaking coextrusion. Effects of alginate flow rate (30–50 mL/min), oil flow rate (4–18 mL/min), applied frequency (80–200 Hz), calcium concentration (1.5–50 g/L) and alginate solution age (24–72 h) and their interactions, on capsules shape and encapsulation payload were studied using response surface method. Analysis exhibited that capsules size was inversely proportional to calcium concentration and frequency. Small capsules presented higher core centricity index while alginate ageing does not have significant effect of the studied responses. Encapsulation payload was strongly related to alginate network structure and influenced by calcium concentration. Multi-response method was performed to produce an optimum model and a phenomenological model was successfully applied to model the effects of CaCl2 and alginate flow rate on beads volume to facilitate further industrial applications.

Optimization of wheat straw co-composting for carrier material development

In modern agriculture large amounts of harvesting residues are produced each year due to the increase of agricultural activities in order to maintain food production for the growing population. The development of innovative fertilizers, able to satisfy nutrient needs without adverse effects on the environment. In order to allow for effective production of a carrier material for smart fertilizers, the objective of this study is to propose a statistical method to optimize the water holding capacity (WHC) and organic matter stability properties of co-composted wheat straw (WS) by using a multi response method. We varied WS size (<1, 1–2, >2 cm), charge of Trichoderma harzianum (0, 7 and 14 discs), and nitrogen addition (0, 0.95 and 1.95 g kg−1). Optimized carrier material was characterized by a higher porosity (WHC 91.7%) than raw WS, associated to structural changes and slightly increased stability as indicated by C:N ratio of the 59.5, slightly alkaline (pH ∼ 8.0), with high OM structural complexity (E4:E6 ∼ 7,9) and enhanced sorption properties (total acidity ∼ 11.6). We conclude that the optimal treatment included co-composting of WS with fine particle size (<1 cm), with a charge of T. harzianum (14 discs), and 0.98 g kg−1 of NH4NO3 to obtain a suitable WS carrier material with high possibility to improve nutrient and water holding capacity in soil.

Production Control Process using Integrated Robust Data Envelopment Analysis and Fuzzy Neural Network

Considering the importance of the quality and responsiveness of manufacturing companies to customers, the most important principle can be considered to be the reduction of the cycle time of the production process. Because in the real world due to measurement errors and inaccuracies of information and the uncertainty of processes the concept Fuzzy is used. Therefore, in this study, the parameters for controlling the process of forming are optimized to reduce the cycle time. Since the optimization of an aspect of quality may modify other aspects, so, to overcome this problem, the multi-response method (Taguchi MRT) has been developed. Also, integrated fuzzy-neural network and data envelopment analysis is used for optimization and analysis purposes. Experimental results are done to measure the effectiveness of this approach in a manufacturing company in Iran.

Multi Response Optimization of Turning Parameter Power Screw Hospital Bed Using Taguchi-Hybrid Method

Power screw is the driving part of a hospital bed which functions to raise and lower the bed. Power screw is an important part of hospital bed products that requires precision and accuracy, then in the manufacturing process by using CNC Turning machine with steady rest. Based on the observations, the defect of power screw caused by worn out tools. It causes chatter on CNC Turning machine. The aim of this study is to reduce the variation of power screw product by conducting experiments in the manufacturing process of power screw. The experiment was done by determining some factors such as spindle speed, depth of cut, coolant and usage time of tool. The specific purpose of this experiment is to reduce variation and simultance optimize are major diameter, minor diameter, pitch diameter, and cycle time. Taguchi multi response method was used for experiment to get simultance optimize process. Multi response case was done by using Grey Relational Analysis (GRA) and Principal Component Analysis (PCA). Experiment based on the orthogonal array of L9 with 3 replications. The results show that by using Taguchi-hybrid method, the optimum condition occurred at spindle speed is 1200 mm/min, depth of cut is 0.1 mm, coolant is 1:30, and usage time of tool is 70%. The result of the experiments carried out showed a decrease in the response variance in diameter and the cycle time faster.

Using the Multi-Response Method with Desirability Functions to Optimize the Zinc Electroplating of Steel Screws

Zinc electroplating is a coating process controlled by several input process parameters. However, the commonly used input parameters for setting the process of zinc deposition are current density, temperature of the coating solution, zinc concentration, deposition time, and concentration of additives (conditioner and brightener). The power consumed in the zinc plating process, coating thickness, increase in coating mass, and corrosion resistance are considered to be outputs or zinc coating parameters. They are widely used when the zinc coating requirements are based on the coating process cost, coating process speed, corrosion resistance, and coating thickness. This paper seeks to determine regression models by the response surface method (RSM) that relate the zinc coating parameters to the input parameters in steel screws. When considering the coating requirements of cost, coating process speed, corrosion resistance, and coating thickness, the optimal input parameters were found by using a multi-response surface (MRS). Input parameters of 0.3 amps/dm2, 20.0 °C, 13.9 g/L, 45 min, 28.5 mL/L, and 2.8 mL/L, respectively (relative to the commonly used input parameters detailed above), were obtained when considering the cost. Considering minimization of the deposition time, the input parameters obtained were 0.5 amps/dm2, 24.6 °C, 13.9 g/L, 45 min, 26.9 mL/L, and 1.1 mL/L, respectively. The optimal inputs to maximize the corrosion resistance were 0.6 amps/dm2, 32.4 °C, 14.0 g/L, 45 min, 28.7 mL/L, and 2.5 mL/L, respectively. Finally, when maximizing the coating thickness, the inputs were 0.7 amps/dm2, 38.4 °C, 12.2 g/L, 45 min, 26.5 mL/L, and 1.5 mL/L, respectively.

A robust posterior preference multi-response optimization approach in multistage processes

ABSTRACTNowadays, many manufacturing and service systems provide products and services to their customers in several consecutive stages of operations, in each of which one or more quality characteristics of interest are monitored. In these environments, the final quality in the last stage not only depends on the quality of the task performed in that stage but also is dependent on the quality of the products and services in intermediate stages as well as the design parameters in each stage. In this paper, a novel methodology based on the posterior preference approach is proposed to robustly optimize these multistage processes. In this methodology, a multi-response surface optimization problem is solved in order to find preferred solutions among different non dominated solutions (NDSs) according to decision maker's preference. In addition, as the intermediate response variables (quality characteristics) may act as covariates in the next stages, a robust multi-response estimation method is applied to extract the relationships between the outputs and inputs of each stage. NDSs are generated by the ϵ-constraint method. The robust preferred solutions are selected considering some newly defined conformance criteria. The applicability of the proposed approach is illustrated by a numerical example at the end.

Wettability of graphitic-carbon and silicon surfaces: MD modeling and theoretical analysis.

The wettability of graphitic carbon and silicon surfaces was numerically and theoretically investigated. A multi-response method has been developed for the analysis of conventional molecular dynamics (MD) simulations of droplets wettability. The contact angle and indicators of the quality of the computations are tracked as a function of the data sets analyzed over time. This method of analysis allows accurate calculations of the contact angle obtained from the MD simulations. Analytical models were also developed for the calculation of the work of adhesion using the mean-field theory, accounting for the interfacial entropy changes. A calibration method is proposed to provide better predictions of the respective contact angles under different solid-liquid interaction potentials. Estimations of the binding energy between a water monomer and graphite match those previously reported. In addition, a breakdown in the relationship between the binding energy and the contact angle was observed. The macroscopic contact angles obtained from the MD simulations were found to match those predicted by the mean-field model for graphite under different wettability conditions, as well as the contact angles of Si(100) and Si(111) surfaces. Finally, an assessment of the effect of the Lennard-Jones cutoff radius was conducted to provide guidelines for future comparisons between numerical simulations and analytical models of wettability.

A new algorithm and multi-response Taguchi method to solve line balancing problem in an automotive industry

One of the most important issues in an assembly line balancing problem is to control a flow of production and manufacturing to provide continuous flow to balance the production line. For this purpose, a line balancing problem was considered for a special assembly line in an automotive factory. A new algorithm was required to deal with balancing an assembly line which consisted of the same job which must be performed by more than one worker at the same time. In this way, the new algorithm was expected to be effective in such a case that jobs were simultaneously completed in a parallel way. In order to measure effectiveness of the proposed algorithm, performance criteria were identified as total number of assembly station, total number of workers, and line productivity. As a result of the application of the proposed algorithm with taking into consideration factors such as cycle time, an allowable number of workers in an assembly station, and an allowable idle time of a worker, alternative solutions were determined in order to measure these criteria. However, these alternative solutions do not give any information about which of the solutions provide not only minimization of the number of assembly station and number of workers on the line but also maximize the line productivity at the same time. Hereby, a multi-response Taguchi method was applied in order to investigate levels of factors which directly affected system performance criteria.

A Multiresponse method for fitting solid-phase activity coefficient models to ternary ion-exchange data

A popular method for fitting solid-phase activity coefficient models in the thermodynamics of ternary ion-exchange has been the Rational method. The standard statistical tests used to compare model functional forms are undefined in the Rational method because all of the dependent variables in the regression (Gibbs Energies) take the value of zero. The present study develops the mathematically equivalent but statistically improved approach of directly fitting Vanselow selectivity coefficients with multiresponse regression. In this multiresponse approach, the Gibbs Energy at equilibrium is set to zero, a selected model is substituted into the equilibrium expression in place of the solid-phase activity coefficients, and the activity coefficient model parameters are optimized numerically until the predicted Vanselow selectivity coefficients are as close as possible to the measured values. This Multiresponse method requires the use of restricted regression to ensure that the equilibrium constants obey the Triangle Rule. An advantage of the Multiresponse method is that it allows for calculation of the coefficient of determination ( R 2) and R 2 adj, which are statistics that can be used to compare solid-phase activity coefficient models. The example solid-phase activity coefficient models compared in this study are the Regular Solution model and a Cox mixture model. When applied to NH 4 +–Ca 2+–K + exchange on vermiculite, the R 2 adj statistics were found to be 0.944 for the Cox mixture model and 0.826 for the Regular Solution model. These results from the Multiresponse method indicate that the Cox mixture model is superior for this dataset.

Burr formation during dry microdrilling operations

Burr formation is a problem in that it interferes with the proper functioning of micro components. A multi-response optimisation method using a Taguchi approach is used for simultaneous minimisation of burr size, namely, burr height and burr thickness when drilling AISI 1018 steel. Taguchi's L25 orthogonal array for each experiment was performed under different conditions of cutting speed, cutting feed, point angle, and lip clearance angle for a 600 µm drill diameter. In the utility concept for multi-response optimisation, the signal-to-noise ratio for each experiment in the orthogonal array was determined by employing weighting factors for burr height and burr thickness. Detailed analysis of ANOVA with the different combinations of weighting factors to determine the contributions of various micro drilling parameters in controlling the burr height and thickness is presented in this paper.

Taguchi robust design for multiresponse drilling optimisation to minimise burr size using utility concept

In the present study, a multiresponse optimisation method using the Taguchi robust design approach and the utility concept is proposed for the simultaneous minimisation of burr height and burr thickness in the drilling of AISI 1018 steel. The experiments were planned as per Taguchi's L25 orthogonal array with each experiment performed under different conditions of cutting speed, feed, point angle and lip clearance angle for a 6 mm drill diameter. In the utility concept for multiresponse optimisation, the multiresponse signal-to-noise ratio for each trial in the array is determined by employing the weighting factors for burr height and burr thickness. The Analysis of Variance (ANOVA) was employed to identify the level of importance of the machining parameters on burr size. A detailed analysis of ANOVA with the different combinations of the weighting factors to determine the contributions of various parameters in controlling the burr size is presented.

P.6.017 The effect of acupuncture on Zùbin (K9) in reducing alcohol craving in alcohol-dependent patients

Dripping coextrusion technology was used to produce core-shell capsules (olive oil/alginate). Mathematical models were developed to study isolated, and interactions impacts of calcium chloride concentration (37.5–187.5 g. L−1), alginate and oil total feed rate (40–108 g.min−1), and dripping height (7–15 cm) on capsules characteristics. Therefore, capsules diameter, sphericity, rupture strength, and encapsulation payload were studied with response surface method using Doehlert matrix. A study showed that capsules characteristics were mainly impacted by calcium chloride concentration and alginate/oil total feed rate. The role of calcium ions on shell structuration mechanisms was highlighted. The process was successfully optimized using multi-response method through desirability function. A mathematical model was developed for the prediction of diameter, sphericity, rupture strength, and encapsulation payload of capsules produced by dripping coextrusion. This model will be useful for further process applications such as fish-egg-like capsules in food industries and “liquid pearls” in cosmetic industries.

Ethanol-Water Separation in the PSA Process

An investigation was carried out on ethanol-water separation employing a PSA adsorption cycle with zeolite 3A as the adsorbent. The cycle was operated under the following operating variables: feed flow (2, 4, 6 and 8 L/h), adsorption temperature (200°C) and adsorption pressures (2, 4 and 6 bar). All experimental runs were performed under vacuum of 0.2 bar in the desorption step. The effect of these variables on the enrichment and recovery percentage of the product, on the productivity and on the total cycle time was studied, using the adsorption pressure as a parameter. The results showed that these variables significantly affect the responses of interest. We also studied the influence of such variables as: adsorption pressures, desorption pressures, flow rates and adsorption temperatures (T), on the enrichment, recovery, productivity and on the total cycle time. The data were obtained from operational cycles in a Kahle's system. The experiments were organized by a three level factorial design. The results obtained were compared with from the fitted empirical equations as well as with the corresponding surface responses and all variables showed to be influential. Last, by an optimal combination of the variables was obtained by means of the ridge analysis method and the optimized multi-response method.

Resolving uncertainty in chemical speciation determinations

Speciation determinations involve uncertainty in system definition and experimentation. Identification of appropriate metals and ligands from basic chemical principles, analytical window considerations, types of species and checking for consistency in equilibrium calculations are considered in system definition uncertainty. A systematic approach to system definition limits uncertainty in speciation investigations. Experimental uncertainty is discussed with an example of proton interactions with Suwannee River fulvic acid (SRFA). A Monte Carlo approach was used to estimate uncertainty in experimental data, resulting from the propagation of uncertainties in electrode calibration parameters and experimental data points. Monte Carlo simulations revealed large uncertainties present at high (>9–10) and low (<4) −log[H+], which result from larger instabilities in the proton balance function in these regions. Uncertainties in speciation parameters were compared for uniresponse fitting (linear programming and least-squares) and multiresponse fitting. Linear programming and least-squares approaches both fit the observed data, but suggest different mixtures of monoprotic ligands. Least-squares fit the data with 21 sites, whereas linear programming fit the data equally well with 9 sites. Multiresponse fitting, involving simultaneous fluorescence and pH measurements, improved model discrimination. Deconvolution of the excitation versus emission fluorescence surface for SRFA establishes a minimum of five sites. Diprotic sites are also required for the five fluorescent sites, and one non-fluorescent monoprotic site was added to accommodate the pH data. Consistent with greater complexity, the multiresponse method had broader confidence limits than the uniresponse methods, but corresponded better with the accepted total carboxylic content for SRFA. Overall there was a 40% standard deviation in total carboxylic content for the multiresponse fitting, versus 10% and 1% for least-squares and linear programming, respectively.

Differential sensitivity of newborns to synthetic vowel stimuli

Three-day-old babies were presented with synthetic speech stimuli and some no-sound trials. Three factors of the speech stimuli were examined: vowel quality change, pitch (F0) change, and stimulus presentation rate. The motor behaviour of the neonates was assessed using a multi-response observation method. The babies responded more when the vowel quality changed than when it did not. In some conditions, pitch variation and stimulus presentation rate also affected d'. The work extends previous findings on newborn auditory sensitivity showing differential responding to steady state vowels and that alterations in F0 can affect behaviour. The method has advantages in permitting several stimuli to be compared as well as studying neonates in states of arousal typical of perinatal experience.

Using a statistical multiresponse method of experimental design in a reaction network study

AbstractA statistical design method for multiresponse models was used in an experimental study of a reaction network. The study involved the vanadia‐catalysed oxidation of o‐xylene using a recirculation reactor. Concentrations of reactants and temperature were used as operating variables, and the concentrations of products were the measured responses.The published design procedure was modified by conducting several runs after each design evaluation to reduce computing costs while retaining the benefits of statistical design and analysis. This enabled network analysis to be conducted efficiently to the limits of the equipment, and pointed the way to improved estimates of the parameters.

The echo multi-response method for surveying value and influence patterns in groups.

A technique originated by Bavelas was modified in 2 ways: (a) the responses of 91 Ss (female clerical employees) were classified by 8 other Ss rather than by E, and (b) a resultant list of salient values was judged by 43 new Ss against a list generated by an expert (a personnel director). Alternate instructions to the judges favored values “important to” (a) employees and (b) the company; as hypothesized, Ss preferred the employee list under the employee condition and no preference was observed under the company condition. E concludes the company may be overlooking employee needs for pleasant personal relations and interest in the work. Methodological and theoretical questions are listed for later study.