Taguchi Orthogonal Array Method Research Articles

Experimental investigation of 3D printed polylactic acid and polylactic acid – hydroxyapatite composite through material extrusion technique for biomedical application

In biomedical industries, composite additive manufacturing are employed for customization, quicker production, efficient use and capital reduction. This experimental work focuses on the development of poly lactic acid (PLA) and novel extruded hydroxyapatite (HA) reinforced poly lactic acid (HPLA) by material extrusion (ME) technique and their properties were compared with that of standard 3D printed PLA. The extruded composite filaments were subjected to thermal characterization (DSC, TGA) and chemical characterization (FTIR) to ensure filament quality and its implementation in ME technique for 3D printing process. In addition, the melt compounded composite filaments were subjected to annealing to observe the influence of heat treatment upon their mechanical properties and thereby to validate their potential to resist breakage during ME process. Taguchi orthogonal array method using MiniTab software is employed to execute the parameter optimization for the 3D printing process. The 3D printed tensile, flexural and impact specimens, using pure PLA and extruded composite filaments, as per American Society for Testing and Materials (ASTM) standards were subjected to a comparative experimental study which showed that 3D printed specimens using PLA and HPLA performed better than that of standard PLA specimens due to the improvement in their crystalline nature. The ruptured specimens were subjected to microstructural characterization (optical microscopy, SEM) to observe failure modes and ash content test was conducted to validate the homogenous distribution HA filler particles in PLA matrix. In addition, mechanical characterization was also performed on 3D printed bone plate/bone scaffold application using extruded filaments of PLA and HPLA, as per ASTM F543 standards, to validate incorporation of the composite filaments in real-time application in biomedical industry.

Determining key factors affecting coconut sap quality after harvesting

The production of coconut sap beverages faces a challenge with the quality of the incoming coconut sap sourced from farmers. The clarification of pivotal factors influencing the quality of coconut sap after harvesting is of paramount importance for fostering mutual benefit between the involved parties. This research focuses on assessing the quality and degradation of coconut sap during the post-harvest stage. It addresses the shortcomings in evaluating coconut sap quality and improper pick-up conditions. To improve these processes, various experiments were designed, including 1) preliminary experiments that explored microbial count, pH, and soluble solids in harvested coconut sap at varying intervals, and 2) the L9 Taguchi Orthogonal Array method. These approaches identify the optimal levels of factors such as cleaning method, storage temperature, and preservative type. By reducing the number of experiments, costs and time were minimized, 3) the 23 factorial design was implemented, reducing the levels of each factor while measuring coconut sap quality based on pH and total soluble solids (representing sweetness) at different post-harvest intervals. The results from the Taguchi method were then used to design the factorial method experiment. The analysis revealed crucial factors influencing coconut sap quality at the 10-h mark. Storage and transportation temperatures, along with the type of preservative, significantly impacted the pH value. However, the washing method and preservative type showed no statistically significant effect on Total Soluble Solids (TSS) value (p > 0.05). Recommendations include using tap water for container cleaning, opting for Payom wood as a preservative, and adhering to cold chain practices for transportation exceeding 4 h, with temperatures maintained below or equal to 10 °C. Swift sap collection within 4 h post-harvest, coupled with stringent temperature control during transportation (not exceeding 10 °C), is advised to ensure optimal quality. Integrating pH with TSS values enhances comprehensive quality assessment, aligning with established best practices in coconut sap handling.

Biodegradable containers from rice husk as substitutes for single-use plastic products

Vietnam ranks among the top four nations for single-use plastic (SUP) waste, trailing only China, Indonesia, and Philippines. The abundant rice husk (RH) by-product of rice cultivation presents an opportunity to fabricate biodegradable containers, potentially supplanting single-use disposables. This study focuses on creating biodegradable containers from RH via thermo-pressing. Utilising the Taguchi orthogonal array method, we examined the impact of the RH to modified starch (MS) ratio (w/w %), pressing temperature (°C), and time (minutes) on the trays’ hardness, colour variation, and density, aiming to refine the manufacturing process. Additionally, variations in adhesive concentrations and glycerol were assessed for their influence on the aforementioned properties. The identified optimal conditions for fabricating viable biodegradable containers were a RH and MS composition of 80% (w/w), with a pressing duration of 3 minutes at 150°C. The resulting product exhibited a hardness of 5.26±0.22 kgF. Moreover, the thickness, density, and colour on the front and back sides were measured at 2.05±0.01 mm, 0.97±0.004 g/cm³, 50.87±0.96, and 48.05±0.87, respectively. Consequently, RH-based materials have emerged as promising candidates for crafting consumer-safe, environmentally benign biodegradable containers.

Application of Cold Sintering Process for Stabilizing Heavy Metals in Municipal Solid Waste Incineration Fly Ash

Municipal solid waste incineration fly ash (MSWI FA) consists predominantly of compounds comprising elements such as calcium, aluminum, silicon, sodium, and others. Additionally, it encompasses a complex mixture of heavy metals, chlorides, sulfates, organic pollutants, and other constituents. The effective and economically viable treatment of MSWI FA poses a formidable challenge for resource cycling at the current stage. In this research report, we adopt a novel low-temperature sintering method called the “Cold Sintering Process” (CSP) as a means to immobilize heavy metals within the fly ash. By utilizing a Taguchi orthogonal array method, we will adjust five control factors in the CSP, including sintering temperature, uniaxial pressure, sintering time, initial water addition, and sodium carbonate dosage. The leaching of cadmium from the fly ash, as measured by the Toxicity Characteristic Leaching Procedure (TCLP), will serve as the quality indicator of products. Through the application of CSP, MSWI FA was transformed into structurally stable ceramic blocks, and the heavy metals within the blocks were effectively immobilized. The results of the experiments showed that MSWI FA under the conditions of a temperature of 300 °C, uniaxial pressure of 312 MPa, sintering time in 60 min, 25 wt% water addition, and 9 wt% Na2CO3 addition could effectively reduce the leaching of cadmium by 77.71%, lead by 21.14%, zinc by 42.37%, and chromium by 99.99%, as compared to the original MSWI FA TCLP results. The X-ray Diffraction (XRD) results indicate that during the CSP, fly ash forms phases such as calcium silicate, rankinite, hydrogrossular, anorthite, and marilite. These phase transformations are considered beneficial for preventing the leaching of internal heavy metals. Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) results reveal that CSP is advantageous for compacting the overall structure, and EDS results further demonstrate that some of the Pb and Zn are carried out from the interior of the blocks, with uneven distribution on the surface of fly ash particles. The aforementioned experimental results serve as preliminary indications of CSP’s capability to stabilize detrimental components within high-purity fly ash. Future research endeavors may entail the refinement of material proportions, modification of experimental parameters, and other methodologies, thus facilitating potential scalability to industrial applications. Such developments align with the overarching goal of resource utilization.

Sensitivity analysis of performance and thermal impacts of a single hydrogen fueled solid oxide fuel cell to optimize the operational and design parameters

In this research, the sensitivity analysis has been performed to investigate the effects of various parameters such as operating temperature, material porosity, flow configurations, air–fuel ratios, and electrolyte thickness on the performance and thermal impacts (stress and strain) generation in the porous electrodes and solid electrolyte. The already developed cell temperature base model of hydrogen-fueled solid oxide fuel cell (SOFC) is used to optimize the operational and design parameters in this study. It is recognized that operating temperature has a noticeable effect on current density and thermal impacts generation. The maximum thermal stress indicated in the middle of the solid electrolyte along the length of the cell for operating temperatures 800–1000 °C are 2088.88 MPa and 2618.18 MPa, meanwhile, the current density varies from 2556.04 A/m2 to 3366.51 A/m2. Taguchi Orthogonal Array Method has been implemented to perform the sensitivity analysis. The analysis of variance (ANOVA) shows that operating temperature has a 51.10% contribution to the overall performance of the cell followed by porosity 23.61 %, electrolyte thickness 16.45%, air–fuel ratio 6.41%, and flow configuration 2.41%.

Using Kriging surrogate model to analyze hydrogen generation with dimethyl ether in partial oxidation catalytic fluidized bed reactor

The study aimed to present a fluidized bed reactor filled with 50% platinum catalytic beads and 50% quartz sand for syngas generation via the partial oxidation of dimethyl ether (DME). For obtaining useful information, experiments were carried out using Taguchi orthogonal array method, which cut test run by 75.3%, with the results being used for constructing the Kriging surrogate model. The model was then modified to reduce the mean square error. It is validated that the model can predict the results reasonably well. The outcome shows that the proposed reactor can self-sustain the syngas reforming reaction without incurring extra heat for reactants preheating. In the operation region, the results show that the start-up temperature is most negligible in hydrogen generation. The yield rate of hydrogen increases in sync with the increase of oxygen's molar ratio and DME, thanks to higher reaction temperature. The results also suggest that the higher the molar ratio of oxygen and DME, the more significant the reverse water shift reaction. Playing a key role in the fluidized bed in the proposed reactor for hydrogen generation, the normalized velocity must be at a proper level, in order to induce bubbling fluidization without causing a lower hydrogen yield, the latter due to the short residence time of reaction caused by excessive velocity. The sensitive analysis of independent variables also proved the inference from the measured results. By comparing with the literature, the performance of the proposed reactor in the present study shows a reasonably well performance. Given focused hydrogen generation, the study's findings can be used as a basis for evaluating DME as a hydrogen carrier and the proposed fluidized bed reaction.

Study on Optimization of WEDM Process Parameters on Stainless Steel

Stainless steel is a material which has high corrosive resistance and oxidation resistance at high temperature with the combination of chromium, nickel, and niobium as a primary constituent. This material which is difficult to machine with complex shape is taken by using wire cut electric discharge machining. Wire electrical discharge machining is a nontraditional process widely taken for cutting and machining for complex shapes. This review paper involves wire cut EDM optimization parameters. Pulse interval, pulse duration, wire feed, voltage, and mean current are the operational parameters. The Taguchi orthogonal array method, analysis of variance (ANOVA), and grey relation analysis (GRA) methods are taken for different kinds of machining various kinds of materials, and different kinds of result with best material removal rate (MRR) and surface roughness (SR) are analyzed. This work suggests the most influencing process parameters and best optimization method for various steel materials.

Slurry erosion behavior of thermally sprayed ceramic nanocomposite coatings on turbine steel

AbstractThe aim of the present study is to investigate the slurry erosion behavior of nano‐yttria‐stabilized zirconia (YSZ) reinforced Cr3C2–25NiCr ceramic nanocomposite coatings deposited on turbine steel. The Cr3C2–25NiCr coating powder, 95% (Cr3C2–25NiCr) + 5% YSZ, and 90% (Cr3C2–25NiCr) + 10% YSZ nanocomposite coating powder deposited on CA6NM steel samples by using high‐velocity oxy‐fuel coating technique. L9 orthogonal array Taguchi method was used to design the experiment. Erosion tests were performed on erosion test rig under hydro accelerated conditions at different levels of various parameters. Erosion tests and analysis of variance resulted that for coated samples, velocity is the major influencing factor followed by slurry concentration, impact angle, and particle size. Velocity was the largest contributor to the mass loss, whereas particle size has the least contribution to mass loss of the coated samples. The scanning electron microscopy analysis of eroded samples revealed that craters, micropores, platelets, plowing, spalling, and so on were responsible for the mass loss of uncoated and coated samples. The incorporation of YSZ nanoparticles decreased the porosity; erodent particles cannot penetrate more deeply inside the workpiece and resulted in less erosion. It has been resulted that 95% (Cr3C2–25NiCr) + 5% YSZ and 90% (Cr3C2–25NiCr) + 10% YSZ ceramic nanocomposite coatings exhibited better erosion resistance as compared to Cr3C2–25NiCr coatings due to high microhardness and low porosity.

Fitting Regression Model and Optimization of Cutting Parameters In Order To Achieve Economical Machining Of a Cryogenic Soaked Magnesium Alloy

Abstract: In present times many industries are giving more importance in reducing the overall cost of production and in this regard reduction in weight of the work material has become necessary which in turn reduces the power consumption required for machining and hence leads to reduction in overall costs. Thus usage of light weight materials has garnered deep interest in the industries. This project deals with the turning of Mg AZ31B alloy for the above stated reasons. The objective of this work is to optimize the influencing cutting parameters like speed, feed, depth of cut and approach angle of the cutting tool by using experimental engineering design techniques like Taguchi method of orthogonal array, analysis of variance method to compute contribution of each of these parameters on the quality of machined output. The response variables taken up for this analysis were surface roughness, material removal rate, tool wear rate and machining time as all these factors governs the quality of the machined product and hence relates to economics of machining. Regression models have been developed in order to study about the mathematical relation between the input cutting parameters and each of the output variables. Contour plots have been drawn to study about interactions between the input cutting parameters and its impact on the output variables. In order to study the effect of cryogenic soaking on the work specimen Vickers hardness test has been performed to check the enhancement of the hardness before and after cryogenic soaking. The experimental data shows that surface roughness is mostly affected by approach angle of the cutting tool whereas material removal rate, tool wear rate and machining time were mostly affected by depth of cut. From the confirmatory test it was evident that Taguchi analysis helps in optimizing the output variables. It was also observed that cryogenic soaking suitably increases the hardness of the material thus making it more machinable. Keywords: Economical Machining, Optimization, Taguchi method, CNC Turning, Mg AZ31B, Regression Modelling, Contour plots, Cryogenic Soaking.

Multiple Responses Injection Moulding Parameter Optimisation Via Taguchi Method for Polypropylene-Nanoclay-Gigantochloa

Recently, the reinforcement of natural fibres into the polymer has been the main topic due to ecological which can sustain the life of our earth. Natural plant fibre composite has advantages in production in manufacturing product due to biodegradability and environmental protection. The injection moulding process is a major interest within the field of manufacturing technology because of the issue of archive the good quality of the product while minimizing the defect of the product that has been produced. Therefore, this research purpose describes the effects of gigantochloa scortechinii (natural fibre) mix with the polypropylene-nanoclay by using multiple objective optimisations for instance Taguchi Orthogonal Array method for injection moulding processing condition towards multiple responses such as melt flow index, flexural strength, warpage, and shrinkage. The compounding material used in this research is polypropylene, nanoclay, the compatibilizer which is polypropylene graft maleic anhydride (PP-g-MA), and gigantochloa scortechinii which known as bamboo fibre. For comparison purpose, the contents of natural fibre selected are 0wt.%, 3wt.% and 6wt.% towards the processing condition which are packing pressure, melt temperature, screw speed and filling time. Based on the signal to noise ratio analysis results, the highest value of S/NQP is at 6wt.% which is 160.6451 dBi followed by 3wt.% (158.1919 dBi) and 0wt.% (134.8150 dBi). Furthermore, the most influential parameter changed with the existence of Gigantochloa Scortechinii from melt temperature into packing pressure. In conclusion, the optimum values for multiple responses have been affected by the present of Gigantochloa Scortechinii.

Influence of the Kinematic System on the Geometrical and Dimensional Accuracy of Holes in Drilling.

This article attempts to show how the kinematic system affects the geometrical and dimensional accuracy of through-holes in drilling. The hole cutting tests were performed using a universal turning center. The tool was a TiAlN-coated Ø 6 mm drill bit, while the workpiece was a C45 steel cylinder with a diameter of 30 mm and a length of 30 mm. Three kinematic systems were studied. The first consisted of a fixed workpiece and a rotating and linearly moving tool. In the second, the workpiece rotated, while the tool moved linearly. The third system comprised a rotating workpiece and a rotating and linearly moving tool, but they rotated in opposite directions. The geometrical and dimensional accuracy of the hole was assessed by analyzing the cylindricity, straightness, roundness, and diameter errors. The experiment was designed using the Taguchi orthogonal array method to determine the significance of the effects of the input parameters (cutting speed, feed per revolution, and type of kinematic system) on the accuracy errors. A multifactorial statistical analysis (ANOVA) was employed for this purpose. The study revealed that all the input parameters considered had a substantial influence on the hole quality in drilling.

Bending response optimization of an ionic polymer-metal composite actuator using orthogonal array method

In the recent past decades, Ionic polymer-metal composites (IPMCs) have been researched in detail due to their flexible characteristics and light in weight. IPMC is most well-known electro-active polymers (EAPs), which can be used in the medical applications, biomimetic, micro robotic actuators, artificial muscles, dynamic sensors and underwater propulsions. Due to their large bending actuation with low voltage sources and biocompatibility, IPMCs are receiving more and more attention to many researchers in recent days. To reduce the experimental costs, the principal factors which are responsible for more bending response are designed in this work using Taguchi orthogonal array method. Multiple process parameters include input voltage and thickness of the fabricated Ag-IPMC actuator was optimized to produce a maximum bending response. Experiments were carried out using L9 orthogonal array to recognize the optimal process parameters. In the optimized conditions, the IPMC actuator exhibited a noteworthy improvement in bending deflection compared to the normal conditions. Under the application of 1.0 V, the bending response increases around 30% in the optimised condition compared to normal IPMC actuator. This study lays a solid foundation for developing high performance IPMC actuator where higher bending displacement is required i.e., in the robotic and biomimetic application with a very small input voltage.

Kinetic modeling and statistical optimization of submerged production of anti-Parkinson’s prodrug L-DOPA by Pseudomonas fluorescens

L-DOPA, a precursor of dopamine, is the drug of choice for Parkinson’s disease, which persists due to decreased levels of dopamine in the brain. Present study emphasis the microbial production of L-DOPA rather than the biotransformation of L-DOPA by L-tyrosine. The production of L-DOPA by bacterial isolates had gained more acceptance due to its more straightforward extraction and downstream processes. Pseudomonas fluorescens was used to produce the L-DOPA in a bioreactor system under submerged condition. The design of experiment-based Taguchi orthogonal array method was adopted for the optimization of production. L-9 orthogonal array using the analysis of mean approach was used to study the effect of different factors viz NaCl, lactose, tryptone, and inducer on the microbial production of L-DOPA. The method mentioned above is less time consuming and does not require any harsh chemicals, proving it to be an eco-friendly process. After optimizing selected factors, i.e., NaCl (1.2 g/l), lactose (1.5 g/l), tryptone (4 g/l), and inducer (0.1 g/l), 16.9 % of enhancement in L-DOPA production with 66.6% of process cost saving was observed. The production of L-DOPA was increased from 3.426 ± 0.08 g/l to 4.123 ± 0.05 g/l after optimization. Subsequently, unstructured kinetic models were adopted to simulate the fermentation kinetics and understand the metabolic process. Fisher’ F test and determination coefficients (R 2) confirmed that the Velhurst–Pearl logistic equation, Luedeking–Piret equation, and modified Luedeking–Piret equation was best fitted with the biomass production, product formation, and substrate utilization, respectively.

Microbial itaconic acid production from starchy food waste by newly isolated thermotolerant Aspergillus terreus strain

In the present study, we have explored the potential of newly isolated Aspergillus terreus BD strain, which can accumulate itaconic acid (IA) at higher temperature. The shake flask cultivation of thermotolerant strain with medium optimized using Box-Behnken Design at 45 °C resulted in IA accumulation of 28.9 g/L with yield of 0.27 g/g. The enzymatic saccharification of the synthetic food waste (SFW) consisting of potatoes, rice & noodles were optimized using Taguchi method of orthogonal array to maximize the release of fermentable sugar. The maximum glucose release of 0.60 g/g was achieved with 10% biomass loading, 5% enzyme concentration, pH 5.5 and temperature 60 0C. The sugars obtained from SFW was integrated with IA production and maximum IA titer achieved with SFW hydrolysate during bioreactor cultivation was 41.1 g/L with conversion yield of 0.27 g/g while with pure glucose IA titer and yield were 44.7 g/L and 0.30 g/g, respectively.

Development, processing and characterization of Polycaprolactone/Nano-Hydroxyapatite/Chitin-Nano-Whisker nanocomposite filaments for additive manufacturing of bone tissue scaffolds

This paper focuses on utilizing the Fused Deposition Modeling (FDM) to manufacture Polycaprolactone/Nano-Hydroxyapatite/Chitin-Nano-Whisker nanocomposite scaffolds and their subsequent characterization for biomedical applications. FDM nanocomposite filaments were manufactured in multiple nanocomposite formulations of Polycaprolactone/Nano-Hydroxyapatite (nHA), Polycaprolactone/Chitin-Nano-Whisker (CNW), and Polycaprolactone/nHA/CNW using a green method. The FDM processing conditions were optimized using Taguchi orthogonal array method. The mechanical, biodegradation, and biocompatibility properties of the bone tissue scaffolds were assessed. A preosteoblast mouse bone cell line was used for cell proliferation and attachment assays. The results indicated that CNW content in the filaments slightly increases the mechanical properties of the 3D printed parts, and the nanocomposite with 3% CNW content exhibited significant improvement in the cell proliferation and attachment properties of the scaffolds. The nHA content considerably improved the mechanical properties of the scaffolds. The nHA and CNW nanofillers increased the biodegradation rate of PCL. In general, considering all types of responses, a green manufactured nanocomposite of PCL/nHA/CNW can significantly increase the biological and mechanical properties of the 3D printed products for bone tissue scaffolds.

Simulation and Optimization of the Acid Gas Absorption Process by an Aqueous Diethanolamine Solution in a Natural Gas Sweetening Unit.

The presence of carbon dioxide in natural gases can lower the quality of natural gas and can cause CO2 freezing problems. Therefore, using reliable techniques for the reduction and elimination of carbon dioxide from natural gases is necessary. The aqueous diethanol amine (DEA) solution’s ability to simultaneously absorb H2S and CO2 from sour natural gases makes it possible to use this solution in the natural gas sweetening process. The goal of this work was to determine the maximum amount of the removed CO2 by an aqueous DEA solution in one of the gas sweetening plants of the National Iranian South Oilfields Company (NISOC). For this purpose, based on the obtained designed experiment results using the L9 orthogonal array Taguchi method, the experiments were conducted and three levels of amine concentrations (25, 28, and 30 wt %), temperatures (40, 50, and 60 °C), and circulation rates of lean amine (220, 240, and 260 m3 h–1) were considered as the key operational parameters on CO2 removal. To evaluate the ability of the HYSYS simulation software and the Kent–Eisenberg thermodynamic model to predict CO2 absorption by an aqueous DEA solution in the gas sweetening process, the field data were compared with the results of the simulation. It was observed that the maximum removal of CO2 is achieved at a lean amine concentration of 30 wt %, a temperature of 40 °C, and a circulation rate of 260 m3 h–1. Also, the experimental results indicate that the effects of the selected process variables on CO2 absorption are not linear and the most effective parameter on carbon dioxide removal is the concentration of amine in an aqueous solution and the temperature of the lean amine has the least effect. Besides, the obtained simulation results are in the range of the unit design basis but have some deviations from field data. The findings of this study can help in better understanding of the selection of the effective variables in the natural gas sweetening process and obtaining their appropriate values to achieve the highest efficiency.

Orthogonal Array Approach Optimization of Catalytic Systems

The paper presents the optimization of the epoxidation process of crotyl alcohol on the Ti-MWW catalyst at atmospheric pressure, based on the Taguchi orthogonal array method. Shown are the influence of the most important process parameters, such a temperature, molar ratio of crotyl alcohol to H2O2, methanol concentration, Ti-MWW catalyst concentration and reaction time. The response functions characterizing epoxidation process were selectivity of transformation to 2,3-epoxybutan-1-ol with respect to reacted crotyl alcohol – S2,3EB1O/CA, conversion of crotyl alcohol CCA, yield of 2,3-epoxybutan-1-ol W2,3EB1O. Based on the calculated signal/noise ratios for individual parameters of the process, their impact on all output parameters was determined and optimal process conditions were determined to reach its the maximum. The empirical verification of this process was also performed by comparing both output parameters predicted and achieved in the tests. This method allows limiting the number of tests required to reach the wished test results, diminution the time needed course for their achievement, and at the same time their expenses.

Community-level decentralized energy system planning under uncertainty: A comparison of mathematical models for strategy development

Distributed energy systems renewable energy are one solution to the environmental and economic concerns of energy use. While energy planning and optimization have been conducted mainly as a mathematical exercise, practical approaches that incorporate the engineering realities and uncertainties are limited. Decision makers find challenges in community energy planning due to the lack of expertise, planning tools, and information. While a multitude of models and tools are currently available, there are no means of identifying the most appropriate or accurate methods, especially considering uncertainty. The main objective of this study is to compare and identify the strengths and limitations of various mathematical modelling techniques used in energy planning for grid connected renewable energy systems. As a case study demonstration, different multi-objective optimization techniques with and without uncertainty consideration (i.e. robust optimization, linear optimization, Taguchi Orthogonal Array method, and Monte Carlo simulation) were applied on a selected neighborhood in British Columbia. The optimization outcomes and the time and effort for evaluation were compared for the different methods. The findings indicate that robust optimization can be used to develop an uncertainty-based decision model. It significantly reduces evaluation time compared to the other methods. Although the presence of uncertainties can change the optimal configuration of a planned energy system, the assessment method itself does not significantly impact the outcomes. The findings of this study will enable the energy planners and researchers to compare different multi-objective optimization techniques, and to select the best for planning renewable energy projects, especially during the pre-project planning stage.

Comparison of novel surface treatments of Al 2024 alloy for al/cfrp adhesive bonded joints

The objective of this study is to investigate the effect of silane and fiber laser treatments on the shear strength and failure type characteristic ofAA2024-T3/unidirectional carbon fiber-reinforced epoxy composite [0]8 laminates (Al/CFRP) adhesively bonded joints. Epoxy-based paste 2 part adhesive (Loctite EA 9396 AERO) was used for adhesive joining. Chemical surface treatment was tested with three different silane concentrations (1, 3 and 5 vol%) applied to AA2024-T3 aluminum plates after cleaning. In addition, 50 W pulsed fiber laser was used to AA2024-T3 aluminum plates for laser treatment. For determining the optimum fiber laser parameters (laser power, frequency and scanning speed) L9 orthogonal array Taguchi method (3 variables and 3 levels) was used. The chemical composition of the fiber laser and silane treated AA2024-T3 sample's was analyzed using Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR–ATR). Shear strength values of the Al/CFRP bonded joints were determined by using single lap shear tests. From the test results, the silane concentration of 3 vol% on AA2024-T3 aluminum plates had a significant effect on shear strength of Al/CFRP bonded joints (16.44 MPa) compared to untreated samples (6.46 MPa). In addition, it was determined that the laser treating parameters of scanning speed of 100 mm/s, frequency of 80 kHz and power of 50 W laser power achieved the optimum surface of AA2024-T3 to be strongly bonded with CFRP (23.68 MPa). After mechanical tests, failure modes were also observed by using the digital camera.

Prediction of uniaxial tensile flow using finite element-based indentation and optimized artificial neural networks

This study derives a uniaxial tensile flow from spherical indentation data using an artificial neural network (ANN) combined with finite element (FE) analysis. The feasibility of the FE-based simulations is confirmed through experimental indentation for various steels. Parametric studies of the FE simulation are performed to generate an ANN training database. An encoding for feature extraction and a hyperparameter optimization is implemented to design the ANN with high predictive performance. The indentation load–depth curves are converted into hardening parameters through the trained ANN. The predictive performance of the FE–ANN model using real-life indentation data is investigated in-depth with thorough error evaluation, and verified by uniaxial tensile tests. The emphasis is made that the mean absolute percentage error between the experimental and simulated indentation data is required to be meticulously controlled below 1% to accurately predict the tensile properties. The validations demonstrate that the applied FE–ANN modeling approach is very robust and captures the tensile properties well. Furthermore, the Taguchi orthogonal array (OA) method that can achieve high efficiency and fidelity with less training data is discussed. The FE–ANN model is concisely designed using the Taguchi OA method and can predict elasticity as well as plasticity.