Taguchi Experimental Design Method Research Articles

Development of a wet digestion method for the analysis of metal soap in fat, oil, and grease deposits using the Taguchi method

Conventional methods for evaluating lipid-based metal salts in fats, oils and grease (FOG) deposits often fall short in assessing the efficiency of grease interceptors for food service establishment wastewater, primarily due to their inadequate specificity for fatty acid (FA) metal soaps. To address this issue, this study introduces a wet acid digestion method developed for the accurate analysis of metal soap content in FOG samples. The Taguchi experimental design method was used to determine the optimal conditions for digestion including temperature, contact time, solid/liquid ratio and type of acid mixture with the aim of more accurately quantifying metal salt concentrations. This work focused on identifying the most effective acid combinations for digesting FOG to enable analysis of commonly found metals. Extensive comparisons revealed that HNO3:H2SO4:H2O2 (1:2:1) and HNO3:H2O2 (1:3) were particularly effective at 180°C for 16h due to their significant oxidation potential. The HNO3:H2O2 (1:3) mixture yielded the highest concentrations of Ca, Mg, Na, and K of 296.38±0.66, 54.95±1.01, 247.65±2.27, and 46.09±3.44mg/g, respectively, aligning with the stringent optimisation principles of the Taguchi method. A one-way ANOVA test validated significant variances in metal contents (p < 0.005), and a t-test indicated a notably higher concentration of Ca compared to other metals. The study presents a sophisticated approach to evaluating the FA metal soap content of FOG ensuring enhanced accuracy and precision compared to established methods.

Simultaneous Cd2+ and organic matter sorption behavior on various microplastics: Modeling of influencing factors using the Taguchi method

In aquatic environments, microplastics (MPs) can serve as a vector for pollutants. Pollutants adsorbed on the surface of microplastics pose a potential risk to aquatic organisms. In this study, the effect of environmental conditions such as duration, pH and conductivity on the Cd+2 and organic matter adsorption capacity, qe,Cd and qe,COD of microplastic type was evaluated using the Taguchi experimental design method. ANOVA results showed that the most effective factor in adsorption capacity was the microplastic type. qe,Cd were listed as > 0.6–0.8 mg/gPP, >0.4 mg/gMDPE, 0.2 mg/gLDPE at 50 mS/cm. It was observed that conductivity had a positive effect on qe,Cd.,qe,Cd for PP in waters with conductivities of 50 mS/cm, 0.8 mS/cm, 0.02 mS/cm at pH 7.0 was found to be ≫ 0.6, >0.2, > 0.4, respectively. qe,Cd and qe,COD showed similar trends. It was determined that the qe,COD at 50 mS/cm was in the order of 15–22 mg COD/gPP, 5–10 mg COD/gMDPE, but not determined for LDPE. After MW and UV artificial aging, qe,COD of virgin PP increased by 31.5 % and 94.4 %, respectively, whereas the qe,Cd decreased by 1.2 % and 24 %.

Optimization of the synthesis parameters and analysis of characteristics of 1,1-diamino-2,2-dinitroethylene

2,2-Dinitroethene-1,1-diamine (FOX-7) is a low-sensitive explosive suitable for various energy-material applications. It can be synthesized based on the nitration and hydrolysis of heterocyclic precursors derived from 2-methylimidazole-4,5-dione (MID) or 2-methylpyrimidine-4,6-diol (MPD). However, more information about its optimal synthesis parameters during production from MPD as a starting material is needed. In this study, Taguchi's experimental design method was used to improve the yield of FOX-7. Verification of the results shows that the optimal synthesis parameters are as follows: the molar ratio of HNO3/MPD is 8, the reaction time is 180 minutes, and the reaction temperature is 15°C; the maximum yield of FOX-7 can reach 79.14%. Furthermore, the synthesized FOX-7 was identified and characterized by nuclear magnetic resonance (NMR) spectroscopy analysis, Fourier transforms infrared spectroscopy (FTIR), Raman spectroscopy analysis, and powder X-ray diffraction (PXRD).

Sensitive quantification of acetochlor and metolachlor in water using Taguchi-optimized DLLME coupled with high-performance liquid chromatography

In this study, we developed a method that is sensitive, simple, and environmentally friendly for quantifying acetochlor and metolachlor. This method combines vortex-assisted dispersive liquid–liquid microextraction (DLLME) with high-performance liquid chromatography (HPLC). HPLC operating parameters and extraction parameters for direct and post-extraction analyses of acetochlor and metolachlor were optimized by employing the Taguchi experimental design method. The optimized HPLC parameters for acetochlor and metolachlor were 1.00 mL/min and 1.2 mL/min flow rate, 40 °C column temperature, and 70/30 (ACN/Water) and 80/20 (ACN/Water) at 210 and 230 nm wavelengths, respectively, for the direct injection method. For the DLLME procedure, 1,2-dichloroethane extraction solvent type, acetonitrile, and methanol dispersive solvent type, 400 µL and 300 µL extraction solvent volumes, and 1.0 mL dispersive solvent volume were the optimized DLLME extraction parameters, respectively. The developed and optimized methods for acetochlor and metolachlor analyses exhibited satisfactory validation results, with excellent linearity, indicated by R2 values greater than 0.99. The limit of detection (LOD) and the limit quantification (LOQ) levels of acetochlor and metolachlor were 28.96 to 31.25 µg/L, and 86.87 to 93.75 µg/L for direct injection, and 1.15 to 1.24 µg/L and 3.47 to 3.75 µg/L for post-extraction, respectively. The DLLME recovery values were within the range of 82.6–99.2 % (relative standard deviations-RSD: 4.47–10.13 %) for acetochlor and 91.1–103.4 % (4.31–7.96 %) for metolachlor. Repeatability and reproducibility results (n = 10) of direct injection and post-extraction methods for fortified acetochlor and metolachlor samples displayed very high precision lower than 2 % RSD.

Investigation and Optimization of The Effect of Anhydrous Borax Mineral on The Vickers Hardness and Indentation Modulus Values of Iron Material

In this study, 5% and 10% by weight of anhydrous borax (AHB) was added to the iron (Fe) matrix material by powder metallurgy method and the effects of the additive ratio on the Vickers hardness (HV), Brinell hardness (HB) and Indentation modulus (EIT) values of the composites (Fe/AHB) were investigated. In the productions carried out using Taguchi experimental design method, AHB additive ratio, and sintering temperature parameters were selected as control parameters that were thought to affect the physical and/or mechanical properties of the Fe/AHB composite materials. The productions were carried out according to the Taguchi L4 orthogonal array, which was created depending on the control parameters and levels. Vickers hardness and indentation modulus measurements of pure iron and Fe/AHB composite materials were performed in accordance with BS EN ISO 14577-1 standard and Brinell hardness measurement was performed in accordance with TS EN ISO 6506-1 standard. According to the signal-to-noise ratio (S/N) analysis performed with the experimental data, it was determined that the 10% AHB additive ratio and 950oC sintering temperature optimized all the investigated properties of the Fe/AHB composite material. It was determined that the values for Vickers hardness, Brinell hardness and indentation modulus increased by 142.03%, 69.32% and 144.11%, respectively, in the levels where the properties of the composite material were optimized compared to pure Fe material. As a result of the qualitative examination of all samples after storage in a comfortable environment without daylight, it was also observed that the anhydrous borax additive delayed the corrosion time of pure iron material.

Multi-objective optimization and machine learning-based prediction of tensile properties of an armchair graphene sheet

Graphene is a widely used nanoparticle in different industries, especially in nanocomposite applications. Prediction of its properties is of great importance for engineers. Therefore, a comprehensive study is first performed in this study to investigate the effect of temperature, strain rate, number of layers, and dimensions on the tensile properties of graphene nanosheets including elastic modulus (E), yield strength (YS), and ultimate tensile strength (UTS) using molecular dynamics simulation. Then, E, YS, and UTS are simultaneously optimized via response surface methodology. To determine the simplest and the most accurate machine learning algorithm for the prediction of tensile properties, three algorithms of Decision Tree (DT), Random Forest (RF), and Gradient Boosted Tree (GBT) are compared and the GBT algorithm is introduced as the best one. Furthermore, the architecture of each algorithm was optimized via the Taguchi design of experiment method to enhance the prediction accuracy. The DT algorithm with a maximum depth of 8 was obtained as the most accurate one.

A Machine-Learning Strategy to Detect Mura Defects in a Low-Contrast Image by Piecewise Gamma Correction.

A detection and classification machine-learning model to inspect Thin Film Transistor Liquid Crystal Display (TFT-LCD) Mura is proposed in this study. To improve the capability of the machine-learning model to inspect panels' low-contrast grayscale images, piecewise gamma correction and a Selective Search algorithm are applied to detect and optimize the feature regions based on the Semiconductor Equipment and Materials International Mura (SEMU) specifications. In this process, matching the segment proportions to gamma values of piecewise gamma is a task that involves derivative-free optimization which is trained by adaptive particle swarm optimization. The detection accuracy rate (DAR) is approximately 93.75%. An enhanced convolutional neural network model is then applied to classify the Mura type through using the Taguchi experimental design method that identifies the optimal combination of the convolution kernel and the maximum pooling kernel sizes. A remarkable defect classification accuracy rate (CAR) of approximately 96.67% is ultimately achieved. The entire defect detection and classification process can be completed in about 3 milliseconds.

Machining performance optimization of graphene carbon fiber hybrid composite using TOPSIS-Taguchi approach

AbstractOptimization of process factors plays a significant role in process efficiency and effectiveness. In this context, an attempt has been made to access the optimized machining factors for polymer nanocomposites including Graphene oxide (GO)/Carbon fiber (CF). To do this, graphene concentration (wt%), feed rate (FR), and spindle speed (SS) have been chosen as governing factors and their performances have been characterized by delamination value (DV) and thrust force (TF). After defining the levels for these factors, the Taguchi experiment design method was used to obtain the experimental trial series. A TiAlN SiC-coated 06 mm drill bit was used in a CNC machine configuration to drill holes. Their corresponding performance values were noted down as DV and TF. TOPSIS method has been incorporated for accessing the measured performance dataset and relative closeness values have been calculated. These relative closeness values have been further subjected to Taguchi’s signal-to-noise ratio (S/N ratio) leading to the evaluation of an optimized parametric combination. 2 wt% of graphene, 100 mm/min of feed rate (FR), and 2100 rpm of spindle speed (SS) make up the ideal machining configuration. The mean response table indicated the SS as the most influential governing contrariant on the TF and DV. In addition, an assessment was conducted to determine the suitability of the model, and it was determined that the stated model does not exhibit any deficiencies or complications.

INTEGRATION OF TAGUCHI AND PROMETHEE FOR CNC MILLING MACHINING PARAMETER OPTIMIZATION ON AA6061

In the manufacturing industry, machining has developed quite rapidly from the use of conventional machines to unconventional machines. Unconventional machines that are often used today are optimize computer numerically controlled (CNC), the use of CNC in the manufacturing industry provides many benefits in product quality and productivity. One of them is CNC milling, this type is one of the main machines on the production floor. Machining optimization becomes the main goal to achieve the ideal response in order to produce products with good and consistent quality and productivity. Surface quality leads to surface roughness, while productivity leads to material removal rate. This study aims to optimize CNC milling machining parameters on AA6061 with Taguchi experimental design and preference ranking organization method for enrichment evaluation (PROMETHEE) method. Machining was controlled using wet machining conditions to maintain temperature during machining. Experiments were conducted nine times with three factors and levels. These factors included spindle speed, feed rate, and depth of cut. The result of this research is the ideal value of the combination of surface roughness and material burning rate which is 0.565 (experiment 3). This best experiment is influenced by spindle speed 2600 rpm, feed rate 65 mm/min, and depth of cut 2.5 mm. Feed rate has the largest contribution in influencing the response which is 43.23%, followed by depth of cut 25.24%, and spindle speed 15.91%.

Development of thermo-mechanical simulation of WC/Inconel 625 metal matrix composites laser cladding and optimization of process parameters

Laser cladding (LC) of industrial parts with tungsten carbide (WC)/Inconel 625 composite is highly regarded for its unique properties, for applications such as repair and improvement of surface and mechanical properties. In order to achieve high quality cladding, with minimal impact on the metallurgical structure and minimal stress and distortion caused by high local heating and cooling rate, it is necessary to determine the important parameters of the process, evaluate and investigate the effect of each one. Today, the numerical solution of this process can help predict, understand and evaluate the characteristics of the LC, and control and optimize it. In this research, using the thermo-elastoplastic simulation of the WC/Inconel 625 composite cladding process using finite element method (FEM) and the arbitrary Lagrangian-Eulerian (ALE) solution method with moving mesh strategy, the properties of the created coating have been evaluated. The laser is modeled with a moving Goldak double ellipsoidal heat source and the physical and mechanical properties of the temperature-dependent materials are considered. The physical and mechanical properties of the composite were extracted from the role of mixture and Ashby's method, respectively. Using Taguchi's experimental design method, the effect of important process parameters on output parameters such as dilution, cladding geometry, heat and stress have been investigated. Finally, the optimal parameters as well as the relationship between the parameters and each characteristic have been obtained using the linear regression model.

Optimization of microencapsulation of polyaspartic acid ester into UV curable epoxy‐acrylate resin using Taguchi method of experimental design

AbstractDue to fast reaction with isocyanates, polyaspartic acid esters (PAAE) can be used for the development of microcapsules for self‐healing coatings. Microcapsules with encapsulated PAAE into shell formed by UV‐cured commercial epoxy‐acrylate resin were produced through oil‐in‐water emulsion polymerization triggered by UV light. The obtained microcapsules were characterized by FTIR, TGA, optical microscopy, and SEM. Various encapsulation parameters, including core to shell ratio, agitation speed, emulsifier type and concentration, solvent type and its concentration in the oil phase, have been selected at four different levels. Microencapsulation was optimized using Taguchi L16 parameter design approach for determination of desired outcome as larger is better (maximal core content) and nominal is better (microcapsule diameter of 50 μm). It was determined that conditions to prepare microcapsules with the highest core content and the microcapsule size close to 50 μm are rather similar requiring core‐to‐shell ratio at about 4:1, low agitation speed of 500–1000 rpm, and the use of two polymeric emulsifiers poly(vinyl alcohol) and Gum Arabic at concentration of about 2%. Primary benefits of UV‐induced shell formation during microencapsulation of active compounds are remarkably shorter time of the process and possibilities to reach high core content and prepare microcapsules of desirable size.

Analysis of the effect of spray mode on coating porosity and hardness when spraying press screws by the high velocity oxy fuel method

Porosity and coating hardness are two very important properties of the coating. In order to achieve low coating porosity and high hardness, a suitable spray mode is desired. In the particular application for press screws with the complex surface, a suitable spray mode plays a significant role in the formation of the coating properties. This paper employs the Taguchi experimental design method combined with ANOVA analysis to evaluate the impact of the spray mode on the porosity and hardness of the coating while spraying the screw surface using the High Velocity Oxy Fuel (HVOF) method. The injection material used is WC HMSP1060-00 +60 % 4070, with its main components being Nickel and Carbide Wolfram. And the press screw material is 1045 steel. The impactful parameters of the spray mode investigated and tested are the flow rate of spray (F) with a range varying from 25 g/min to 35 g/min, spray distance (D) with a range of values varying from 0.25 m to 0.35 m, and an oxygen/propane ratio (R) from 4 to 6. The analysis shows that the spray mode significantly affects the coating properties, and a suitable set of spray parameters is found to achieve low coating porosity and high coating hardness. The spray mode with the lowest porosity is achieved at a spray rate (F) of 35 g/min, a spray distance (D) of 0.3 m, and an oxygen/propane ratio (R) of 6. The interactions between D and R, as well as between F and D, are statistically significant, influencing each other's effects on porosity. However, the interaction between F and R is relatively low, indicating that changes in one parameter have less impact on porosity when the other parameter is varied. Similarly, for the highest coating hardness, the optimal spray mode includes an F of 35 g/min, D of 0.25 m, and R of 6. There is a significant interaction between F and D, while the interaction between F and R is relatively low. Notably, there is no interaction between F and R

Optimizing process parameters of fused deposition molding for 3D printing customized control of polyetheretherketone scaffolds

Polyetheretherketone (PEEK), with good biocompatibility and similar mechanical properties to natural bone, is extensively employed in the manufacture of prostheses. However, the precision and mechanical properties of current implants are major challenges for clinical applications. In this study, the effect of pore size, raster angle and printing temperature were investigated on length, width, thickness, material consumption, compressive strength and Young’s modulus. Taguchi design of experiment method was used to reduce the number of experiments and optimize the printing process parameters. Finally, predictive analysis was exploited to give the optimal set of process parameters. Experimental results indicated that the approach applied in this work provided more accurate predictions and control of the response variables. The maximum compressive strength and compressive modulus of PEEK scaffolds reached 43.4 MPa and 253.3 MPa, respectively. Therefore, the methodology of present work has the potential to meet the demand of design precision and manufacture of customized bone substitutes.

Experimental investigation of multi-additive fuel blend and its optimization for CI engine performance and emissions by the hybrid Taguchi- TOPSIS technique

In recent years, the critical stage of air pollution and government stringent emission norms like Bharat Standard VI in 2020 in India and Euro VI in European countries, along with the promotion of electric vehicles, has made the future of diesel vehicles unpredictable. The present work correlates and tries to overcome the emission issue by improving fuel properties using a novel multi-additive fuel blend which can control engine emission, mostly NOx, without compromising efficiency and operating fuel economy. Using experimental and literature studies, three additives were identified for creating a novel multi-additive fuel blend, viz. dimethyl carbonate, 2-ethylhexyl nitrate and ethyl acetate. Using the Taguchi Design of Experiment method, sixteen test samples having different combinations of these additive were identified for experimental trials to create sufficient and suitable test data for the optimization process. Technique for Order of Preference by Similarity to Ideal Solution is a Multi Criteria Decision Making optimization process, is performed to identify the optimized multi-additive fuel blend coded as D8EH6E4. Blending the optimized multi-additive sample D8EH6E4 with diesel fuel reduced NOx formation by an average of 19 % while causing a substantial drop in smoke at higher load conditions without adversely affecting engine performance and fuel economy.

Design of special vacuum fan for use in the ship scraping process

The outer surfaces of ships should be smooth for efficiency and safety. With the scraping process, the performance of the ship is increased and the possible negative effects are minimized. One of the biggest causes of corrosion (abrasion) that may occur over time is rough surfaces. The scraping process, which is one of the most important processes in shipyards, is very laborious, and at the same time, the dust and chemical wastes that occur during the process reveal extremely harmful results for the environment. Thus in this work the optimum design and operating parameters (best efficiency) of the fan specially designed for the removal of dust and solid wastes from the environment with a closed system, which is generated during the surface cleaning process using abrasive blasting materials were obtained. Taguchi experimental design method was applied. Afterwards, the effect of which parameter on the results was determined with the Anova Statistical Analysis method. The same values were obtained in the results obtained by using both the experimental studies obtained by the classical method and the statistical data of the fans designed within the scope of the study, of which 9 prototypes were manufactured. The values of 100 Hz frequency, suction pipe diameter of 110 mm and wing width of 650 mm were determined as the most optimum results.

Multi-process regulation of novel brominated flame retardants: Environmentally friendly substitute design, screening and environmental risk regulation

Novel brominated flame retardants (NBFRs), one of the most widely used synthetic flame-retardant materials, have been considered as a new group of pollutants that potentially affect human health. To overcome the adverse effects of NBFRs, a systematic approach for molecular design, screening, and performance evaluation was developed to generate environmentally friendly NBFR derivatives with unaltered functionality. In the present study, the features of NBFRs (long-distance migration, biotoxicity, bioenrichment, and environmental persistence) were determined and characterized by the multifactor comprehensive characterization method with equal weight addition, and the similarity index analysis (CoMSIA) model was constructed. Based on the three-dimensional equipotential diagram of the target molecule 2-ethylhexyl tetrabromobenzoic acid (TBB), 23 TBB derivatives were designed. Of these, 22 derivatives with decreased environmental impact and unaltered functional properties (i.e., flame retardancy and stability) were selected using 3D-QSAR models and density functional theory methods. The health risks of these derivatives to humans were assessed by toxicokinetic analysis; the results narrowed down the number of candidates to three (Derivative-7, Derivative-10, and Derivative-15). The environmental impact of these candidates was further evaluated and regulated in the real-world environment by using molecular dynamics simulation assisted by the Taguchi experimental design method. The relationship between the binding effects and the nonbonding interaction resultant force (TBB derivatives-receptor proteins) was also studied, and it was found that the larger the modulus of the binding force, the stronger the binding ability of the two. This finding indicated that the environmental impact of the designed NBFR derivatives was decreased. The present study aimed to provide a new idea and method for designing NBFR substitutes and to provide theoretical support for restraining the potential environmental risks of NBFRs.

Green synthesis of iron oxide nanoparticles by Taguchi design of experiment method for effective adsorption of methylene blue and methyl orange from textile wastewater

Since the beginning of the industrial revolution, the uncontrolled discharge of wastewater from textile and dyeing industries into water bodies is environmentally challenging to humans and the ecosystem. Using Cola nitida (CN) leaves extract, Taguchi optimization method was successfully applied to achieve the green synthesis of iron oxide nanoparticles (CN–Fe2O3NPs). Textural properties, nature of surface functional groups, crystalline structure and surface morphology of CN–Fe2O3NPs were studied. The performance of CN–Fe2O3NPs was tested for methylene blue (MB) and methyl orange (MO) removal from textile wastewater. The optimal surface area of 125.31 m2/g was achieved for the CN–Fe2O3NPs using the CN extract volume (10 mL), precursor concentration (2 M), contact time (30 min) and calcination temperature (600 °C). Overall, calcination temperature had the highest effect than other synthesis parameters. The characterization revealed the presence of crystalline hematite with Fe–O, Fe–O–Fe functional groups and a regular-shaped porous material. Furthermore, the adsorption capacity of 530.406 and 527.835 mg/g was obtained for MB and MO within 60 min using a nanoadsorbent dosage (25 mg/L), initial dye concentration (100 mg/L) and temperature (50 °C). The reusability and stability of the CN–Fe2O3NPs revealed successful reuse after six cycles without any damage to the structure as was corroborated by the fourier transform infrared (FTIR) spectroscopy. The experimental data were suitably fitted by the Langmuir isotherm and pseudo-second-order kinetic models denoting a chemisorption and monolayer nature of the adsorption process. The thermodynamic parameters indicate an endothermic and spontaneous adsorption process. Hence, the high separation effectiveness against the dye molecules with good performance and stability indicate the great potential for the green synthesized CN–Fe2O3NPs in water purification.

Optimization of Characteristics Polymer Composite Reinforced Kenaf and Jute Fiber Using Taguchi-Response Surface Methodology Approach

ABSTRACT The use of composite materials with natural fiber reinforcement (CMNFR) has experienced rapid development in the automotive industry to apply synthetic materials that are expensive and not environmentally friendly. Biocomposite is a composite consisting of a polymer matrix and natural fiber reinforcement. Natural fiber materials are used as a substitute for conventional non-renewable reinforcing materials. This study uses the vacuum-assisted resin infusion (VARI) process to fabricate composites using woven kenaf and jute from natural fiber. The Taguchi experimental design method with L27 3 as an orthogonal array matrix was used in this research to obtain the optimum CMNFR fabrication parameters. Response Surface Methodology is used to obtain the optimal response value based on microstructural analysis. The factors used were NaOH treatment (4, 6, 8 wt%), water absorption test (6, 12, 24 hours), and fiber type (KF, JF, KF-JF). The study’s results found a combination of optimization of CMNFR manufacturing parameters using RSM, namely, A1B1C2 with a mean material strength of 0.241 J/mm2 (impact strength) and a combination of A1B3C1 parameters with a mean material strength of 94.8650 MPa (flexural strength). It was also found that the presence of contaminants and voids harmed the mechanical properties.

Numerical Study of the Effect of Angle and Location of the First and Second Steps on the Performance of Planing Hull and Their Optimization Using the Taguchi Statistical Method

Providing steps at the bottom of a high-speed craft could decrease the resistance and enhance the longitudinal stability by dividing a single pressure hump into several ones and extending the hydrodynamic pressure towards aft of the vessel. In the present paper, the effects of the fore and aft steps’ locations and angles on double-stepped hulls are investigated systematically via a numerical approach. The parent model investigated in this study is a model of a high-speed recreational craft called Cougar, with a 1 : 5 scale. The three-dimensional analysis of the model is conducted via the finite volume method, and the free surface is tracked using the volume of the fluid technique. The computational domain is discretized by the overset technique, and the calculations are validated via experimental data. Overall, 27 numerical tests designed by the Taguchi experiment design method are simulated, and the resistance, trim, and rise-up values are calculated at 8 to 10 m/s speeds. The findings support the notion that the resistance increases by increasing the distance between the fore step and vessel stern. In addition, increasing the distance between the aft step and vessel stern and the increase of the angle of the fore step leads to reducing the vessel resistance. However, the results showed that finding a sensible relationship between the angle of the aft step and resistance requires more investigation. The findings revealed that the interactional effects between the angles of the aft and fore steps are the most considerable among all studied interactional effects. Among the all studied configurations, the lowest resistance was experienced by the model with an aft step at 25% of the vessel’s length to the stern, having an angle of 150°, and a fore step at 40% of the vessel’s length to the stern, having an angle of 180°.

A novel strategy for foodstuff can coatings: Hybrid resinous materials beside silica nanoparticles

For many years, Bisphenol A (BPA) based epoxy resins have been used as coating material for foodstuff cans because of their appropriate properties. Recently, with attention to the harmful health effects of BPA derivatives, limitation of the usage of epoxy resins has escalated. In this research, using Taguchi experimental design method, different nanocomposite coatings based on hybrid resinous materials containing different amounts of epoxy and polyester and silica nanoparticles were formulated. The migration properties of formulated coatings were investigated based on the standard methods. The results showed that the 45 wt.% replacement of epoxy by polyester resin in combination with 2 wt. % of nano silica, had not any inverse effect on needed mechanical, physical and chemical properties of optimized formulation and, at the same time, migration of BPA and toxic materials were in the acceptable ranges, based on the EN1186-EU 10:2011 standard.