Mixture Design Approach Research Articles

Investigations of thermophysical properties of submerged arc welding slag using a rutile-acidic flux system

For TiO2–SiO2–MgO and SiO2–MgO–Al2O3flux system, the thermophysical and physicochemical behaviour of submerged arc slags studied. Slag plays an essential role in shielding the weld joint from atmospheric contamination. The mass percentage of each flux ingredient evaluated by the X-ray fluorescence technique. Twenty-one slags developed based on the mixture design approach. Thermogravimetric, DSC, and Hot-disc techniques used to analyze submerged arc slags. Thermogravimetric & DSC analysis was performed from 25 ºC to 900 ºC to find the thermal properties. The density measurement of slag performed at ambient temperature. Bond-behaviour was studied by Fourier transform infrared spectroscopy (FTIR) technique. Regression models for different slag properties developed. The multi-objective technique utilized to optimize different slags.

A mixture design approach for mitigating cracking issue of asphalt concrete pavement

The traditional Superpave mixture (SP4) is designed at 4.0% air voids while the mixture is compacted at 7%-8% air voids in the field with the belief that the pavement will achieve its ultimate density after several years. Several studies have reported that the maximum density that a pavement can achieve is about 94%. This higher air voids provide an easy pathway for air into the pavement, which eventually accelerates the aging process and results in premature cracking of the pavement. To this end, this study provides an enhanced mixture design approach in which mixture will be designed at 5% air voids (SP5) and compacted at the same air voids in the field so that the higher in-place density will enhance the fracture strength of the mixture and minimize the aging process. First, the traditional SP4 mixture design has been completed using two different aggregates and binders. Then, the SP5 mixture design is accomplished by reducing the design number of gyrations from 100 to 55 and adjusting the aggregate gradation while keeping the effective binder content the same as SP4. The laboratory Hamburg Wheel Tracking Device (HWTD) and Semi-Circular Bending (SCB) tests have been conducted to evaluate the rutting and fracture properties of the SP4 and SP5 mixtures. In addition, Thermal Stress Restrained Specimen Test (TSRST) has also been conducted to observe the low-temperature cracking performance of the SP4 and SP5 mixtures. The HWTD test results reveal that the SP5 mixture has equal or better rutting resistance properties than the SP4. Based on the fracture energy obtained from SCB test data, the SP5 mixtures exhibit better-cracking resistance than that of SP4 mixtures, which implies that the SP5 mixture will delay in crack initiation and propagation. The TSRST test results show that the SP5 mixture has improved low-temperature cracking property compared to the SP4 mixture. Therefore, the SP5 mixture design procedure will mitigate the cracking issue of asphalt concrete pavement.

Study of weld bead chemical, microhardness & microstructural analysis using submerged arc welding fluxes for linepipe steel applications

Linepipes above 16″ diameter are often submerged arc welded. Weld mechanical as well as metallurgical properties are widely affected by the flux composition. Flux composition and welding parameters play an important role in determining the good bead quality and mechanical properties of the welded joint. In present study submerged arc welding fluxes were formulated using constrained mixture design approach. Twenty one submerged arc welding flux compositions based on CaF2–CaO–SiO2 and Al2O3–CaO–SiO2 flux system were designed using extreme vertices design approach. Regression models were developed in terms of individual, binary and ternary mixture flux constituents for submerged arc series of bead on plate weld deposits (API 5 L X70 pipeline steel). By using F-test regression mathematical models have been checked for 95% significance level. Effect of formulated fluxes on silicon, copper, molybdenum, titanium and chromium content was studied using a multi-layer weld deposits. All binary mixtures C·Al, S·CF, S·Al and C·Al have significant increasing effect on silicon content in a bead on plate weld deposits while S·Al is the most effective synergistic binary mixture. Individual and binary flux mixtures tend to decrease the copper content in a bead on plate weld deposits.

Statistically designed cellulase mixture for saccharification of pretreated Sorghum durra stalk

The potential of least explored Sorghum durra as a feedstock for enzymatic saccharification in bioethanol production was evaluated as only one report is available. The pretreatment specific, optimization of saccharification of Sorghum durra stalk (Sds) was carried out. The concentrations of crude recombinant endoglucanase (BaGH5-UV2), cellobiohydrolase (CtCBH5A) and β-glucosidase (CtGH1) in cocktail were optimized for saccharification of acid or base pretreated Sds by using mixture design approach. Optimized percentage ratio of BaGH5-UV2, CtCBH5A and CtGH1 with total enzyme loading 2000 U/g of pretreated Sds for acid pretreated Sds was 43.1:10.0:46.9 and for base pretreated Sds was 80:10:10 at 48 h of saccharification. The base pretreated Sds showed 1.8-fold (165.6 mg/g of pretreated Sds) higher total reducing sugar (TRS) yield and 1.2-fold (81.7 mg/g of pretreated Sds) higher glucose yield than acid pretreated Sds. This low sugar yield from acid pretreated Sds was due to the presence of higher acid insoluble lignin content, 11.9 % (w/w) than the base pretreated biomass (2.2 %, w/w). In acid pretreated Sds, ANOVA data showed 3.7-fold higher F value (111.58) for BaGH5-UV2 and CtGH1 interaction than the base pretreated Sds. This indicated that the synergism between BaGH5-UV2 and CtGH1 for acid pretreated Sds was significantly higher. This was due to lower intact hemicellulose content (10.6 %, w/w) in acid pretreated Sds than base pretreated Sds (21.8 %, w/w). The optimized enzyme ratios for saccharification of acid pretreated Sds gave maximum TRS and glucose yield at 72 h, 113 and 85 mg/g of pretreated Sds, respectively, unlike base pretreated Sds at 96 h, 211 and 174 mg/g of pretreated Sds, respectively. These results showed that the ratio of cellulase enzymes in cocktail and their synergism depends on the type of pretreatment used for biomass. Thus, this in-house cocktail design specific to pretreatment can improve the biomass saccharification at large scale.

Optimization of beef patties produced with vegetable oils: a mixture design approach and sensory evaluation

Abstract The exaggerated consumption of fast food and ready to eat products is a common practice which results in an unbalanced intake of saturated fats. In order to improve the fat composition of beef patties, mixture design was used to optimize the inclusion of pomace olive oil (POO) and canola oil (CO). Cooking yield, moisture retention, diameter reduction, color, texture and sensorial parameters were accessed. Models showed, with a 94.5% of variance explained, that the inclusion of POO and CO should be limited in order to maintain a low acidity index and texture parameters comparable to commercial burgers of similar composition. Preference test, consumer profile, acceptability, penalty analysis and Check-all-that-apply (CATA) results indicated that a parcial replacement of pork fat (PF) can be considered. In sum, formulations with improved fat composition (50 or 33% replaced animal fat by POO and CO) were obtained.

Modeling and optimization of chemical composition of nano/amorphous Fea.Nib.Nbc.Zrd alloy prepared via high-energy ball milling with enhanced soft magnetic properties; A mixture design approach

Abstract In this study, the design of experiments was employed to study the influence of chemical composition on soft magnetic properties and the structure of nano/amorphous Fea.Nib.Nbc.Zrd alloys. The designed alloys were produced via mechanical milling of pure elements for 20 h at 400 rpm and ball to powder ratio of 20:1. As a result of optimization, the atomic percent values of Fe, Ni, Nb, and Zr were proposed equals to 31.3, 48.7, 0, and 20, respectively for the proposed optimized alloy. Experimental data confirmed the enhanced soft magnetic properties of proposed alloy as the coercivity equal to 70.66 emu/g and saturation magnetization equal to 17.09 Oe. Also, the investigation of microstructure of proposed alloy revealed the co-existence of crystalline region surrounded by an amorphous phase.

Optimization of acorn (Quercus suber L.) muffin formulations: Effect of using hydrocolloids by a mixture design approach

Acorn flour was used as a gluten-free ingredient to produce acorn muffins. Interaction effects between xanthan (X), carboxymethyl cellulose (CMC) and κ-carrageenan (κ-C) (0–0.3%) on the height and textural parameters of the formulated acorn flour muffins were investigated using a mixture design approach. Each studied parameter was optimized individually. Then, an optimal formulation giving a product with characteristics as close as possible to those of a wheat flour muffin sample was determined. Results revealed that addition of each hydrocolloid separately, or their ternary combination improved the muffin height. Optimal height value was predicted to reach 3.96 cm when using 26.8% X, 50.5% CMC and 22.7% κ-C. As regard to textural parameters (firmness, cohesiveness, springiness and adhesiveness), presence of the three hydrocolloids had an antagonistic effect. The best hydrocolloids mixture giving optimal height (3.92 cm), firmness (3.19 N) and adhesiveness (0.66 N) was that containing 20.5% X and 79.5% CMC.

Optimization of antibacterial and mechanical properties of an active LDPE/starch/nanoclay nanocomposite film incorporated with date palm seed extract using D-optimal mixture design approach

A novel active LDPE/TPS nanocomposite films containing date palm seed extracts (Kabkab variety) were developed using D-optimal mixture design. 20 different blends of components including LDPE, TPS, Cloisite 20A, PE-g-MA, EDTA and date palm seed extract in different proportions were prepared. Using trace and counter plots the effects of each component on the mechanical and antibacterial properties of the composites were studied. The results showed that the films containing a mixture of date seed extract and EDTA had notable antibacterial activity against E. coli and S. aureus; however, these components weakened the mechanical properties of the prepared films. At the same time Cloisite 20A nanoparticles strengthened the films mechanical properties.The optimized formulation for the overall best antibacterial and mechanical properties was 67.5 wt% for LDPE, 4.1 wt% for date seed extract, 2.8 wt% for Cloisite 20A and 2.5 wt% for EDTA. The studied properties of the manufactured film samples were close to the values predicted by the model.

Investigations on dissimilar welding of P91/SS304L using Nickel-based electrodes

ABSTRACT This article is an attempt to develop Ni-based shielded metal arc welding electrodes to join SS304L austenitic stainless steel to P91 martensitic steel used in power plant applications. Nickel-based electrodes were prepared using a mixture design approach. Dissimilar welds of SS304L/P91 were fabricated using Nickel-based laboratory-developed electrodes and commercially available electrode (ENiCrFe-3). A comparison was drawn between the weld characteristics of commercial and laboratory-developed electrodes. Experimentation was performed to evaluate the microstructural changes and mechanical characterization which includes hardness profile, tensile strength, the impact strength of the base materials, as well as dissimilar welds. Welds fabricated with a laboratory-developed electrode possesses better weld quality and mechanical characteristics. A higher amount of Ni and Cr was observed in the laboratory developed electrodes as compared to the commercial electrode.

Enhanced Lycopene Extraction from Tomato Peels by Optimized Mixed-Polarity Solvent Mixtures

Mounting evidence from clinical and epidemiological studies suggests that lycopene, the most abundant carotenoid in tomatoes, may be beneficial in the prevention or treatment of some important diseases. Ripe tomato peels are the richest source of lycopene, but the use of conventional solvent extraction methods without pretreatment of the plant material results in very poor recovery. The reason lies in the localization of lycopene in the plant tissue and the low permeability of the latter to solvent molecules. In this paper, a mixture design procedure was used to formulate solvent mixtures allowing the recovery of lycopene from non-pretreated tomato peels. Two ternary systems were investigated: (a) n-hexane–ethanol–acetone and (b) ethyl lactate–ethanol–acetone. Optimization of the ternary mixture composition led to a recovery of over 90% of the lycopene present in the peels. The high extraction efficiency was explained in terms of lycopene affinity combined with the ability to swell the plant material. A tomato oleoresin with high antioxidant activity and a lycopene content of about 13% (w/w) was also produced. Overall, the results indicate that highly effective solvents for direct recovery of lycopene from tomato peels can be easily prepared by a mixture design approach.

Optimisation of wall material composition of freeze–dried pumpkin seed oil microcapsules: Interaction effects of whey protein, maltodextrin, and gum Arabic by D–optimal mixture design approach

D–optimal mixture design approach was used for optimisation of wall material composition including whey protein concentrate (WPC), maltodextrin, and gum arabic to effectively encapsulate cold–pressed pumpkin seed oil (CPPSO) by freeze–drying. Interaction and/or synergistic effects of these wall materials on the rheological and physical properties of oil–in–water emulsions and some physicochemical characteristics of microcapsules were examined. Rather than individual effects of each wall material component, effects of their interactions were dominant on the quality attributes of emulsions and microcapsules. Microencapsulation by freeze–drying decreased α–, γ– and total tocopherols and total phenolic contents (TPC) of CPPSO. Two wall material compositions (12.28% WPC + 5% maltodextrin +2.70% gum arabic or 10% WPC + 5% maltodextrin +5% gum arabic) with increased emulsion stability, encapsulation efficiency, solubility, total polyunsaturated fatty acids (PUFA) content and decreased wettability time and total saturated fatty acids (SFA) content were predicted by optimisation tool.

Towards water-insensitive CO2-binding organic liquids for CO2 absorption: Effect of amines as promoter

Abstract CO2-binding organic liquids (CO2-BOLs) or reversible ionic liquids (RILs), are non-aqueous CO2-triggered switchable polarity solvents which can be used for energy efficient CO2 capture. In this study, the novel three-component CO2-BOLs are introduced. They are comprised of 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) as an organic superbase and an alkanol in conjunction with an amine as a promoter. Screening experiments were performed to find the best combination of CO2-BOL components based on CO2 loading and absorption rate. The variables were: the type of alcohol (methanol, n-butanol, sec-butanol, tert-butanol and 1-hexanol) and the type of amine (EEA, MEA, AMP, DEA, AEEA, PZ, TETA and DETA) using the DBU superbase. Statistical mixture design approach using Minitab 18 software was implemented for the design of experiments, modeling and optimization of CO2 loading at the fixed temperature of 35 °C and the initial CO2 pressure of 25 bar. It was found that DBU/MeOH/MEA system with the molar ratio of 0.3/0.17/0.53 has the maximum equilibrium absorption (αeq) and CO2 uptake within 30 min (αR) of 0.444 and 0.267 mol CO2/mol solvent, respectively. Amine additives promoted absorption efficiency and inhibited formation of solid precipitates (bicarbonate salt) in the presence of water impurity. Characterization of ionic species and explaining the water-inhibitory effect of MEA were obtained from FTIR, 1H NMR and 13C NMR spectroscopic analysis. Equilibrium CO2 solubility data in DBU/MeOH (1/2) and DBU/MeOH/MEA (0.3/0.6/0.1) CO2-BOLs were also obtained at temperatures of 308.2 and 318.2 K and pressure range of 0–33 bar. The results of present study can be used to effectively utilize CO2-BOLs in the wet conditions with higher absorption efficiency and lower regeneration energy.

Multiple response optimization to determine the suitable solvent for the extract production from defatted grape seed powder: A simplex lattice mixture design approach

In this study, effects of different solvents (ethanol, methanol and water) on bioactive performance of defatted grape seed powder (GSP) were investigated using simplex lattice mixture design approach. Also, multiple response optimization process was applied to determine the best solvent type for the high bioactive GSP extract production. For this purpose, the bioactive compound concentrations and their antioxidant and antiradical properties were characterized and the effect of solvent type on the processing variables was modelled. Total phenolic and flavonoid contents of GSP ranged between 0.31-7.29 mg GAE/g and 44.3-537.4 mg CE/kg sample. In addition to that, DPPH and ABTS.+ radical scavenging activity of the samples were in the range of 2.11-80.5% and 0.31-4.08 μg Trolox/ g sample. The effect of solvent type showed a significant effect on all studied bioactive parameters and the best solvent mixture was determined as ethanol (33.84%), methanol (20.17%) and water (45.99%) by the considering the all studied parameters.

Optimization by mixture design approach

Purpose The purpose of this study is to fit an appropriate mathematical model to express response variables as functions of the proportions of the mixture components. One purpose of statistical modeling in a mixture experiment is to model the blending surface such that predictions of the response for any mixture component, singly or in combination, can be made empirically. Testing of the model adequacy will also be an important part of the statistical procedure. Design/methodology/approach A series of mortar using air lime, marble and ceramic sanitary waste aggregates were prepared for statistically designed combinations. The combinations were designed based on the mixture-design concept of design of experiments; this mortar is often used as a filler material in restoration projects. The aim of this work is to find an optimal composition of a paste for the manufacture of air lime mortar with ceramic and marble waste. This investigation aims to recommend mix design for air lime-based mortar, by optimizing the input combination for different properties, and to predict properties such as mechanical strength, thermogravimetric and x-ray diffraction analysis with a high degree of accuracy, based on a statistical analysis of experimental data. Findings This paper discusses those mortar properties that architects, contractors and owners consider important. For each of these properties, the influence of ceramic and marble waste in the air lime mortar is explored. The flexibility of lime-based mortars with waste materials to meet a wide range of needs in both new construction and restoration of masonry projects is demonstrated. Originality/value The objective of the present investigation is to recommend mixture design for air lime mortar with waste, by optimizing the input combination for different properties, and to predict properties such as compressive strength, flexural strength with a high degree of accuracy, based on the statistical analysis of experimental data. The authors conducted a mixture design study that takes into account dependent parameters such as the constituents of our air lime-based mortar where we have determined an experiment matrix to which we have connected the two responses, namely, compressive and flexural strength. By introducing the desirability criteria of these two responses, using JMP software, we were able to obtain a mixture optimal for air lime mortar with ceramic and marble waste.

Optimisation of protein‐enriched gluten‐free layer cakes using a mixture design

SummaryThe effect of different protein mixtures (pea, whey and egg white proteins) on the physical characteristics of batters and baked gluten‐free layer cakes after substituting 45% of flour was evaluated. A mixture design approach was used to determine the interaction effects of the three proteins on the cakes physical characteristics. For batter density, two interactions were observed, and higher values were found for batters containing a mixture of 60–80% egg white and 20–40% whey than in batter containing only one of these proteins, or a pea content of 70–90% than in batter containing only pea. For batter viscosity, significant interactions between egg white and pea, and between whey and pea proteins were observed, which explains the gentler decrease in viscosity at higher egg white and/or whey protein ratios. Regarding hardness, an interaction between egg white and whey occurred, and increasing whey content helped to reduce hardness to a greater extent than increasing pea content.

Valorization of seasonal agri-food leftovers through insects

Most of the leftovers from agricultural productions and industrial processing of vegetables are currently discarded as waste, augmenting production costs and environmental impacts. Black soldier flies (BSF) are non-pest insects that can grow on various types of organic materials. The larvae initially act as fast and efficient bioconverters, before being further valorized as biomass rich in proteins, fats and chitin. The aim of the present study was to exploit the potential of BSF prepupae reared on vegetable leftovers with high seasonality, and to obtain compounds with high added value and further industrial and agronomic uses such as food/feed, soil improver or fuel. The optimization of BSF rearing substrates based on different leftovers combinations was performed through a Mixture Design approach. Initially, a database was built detailing the availability, seasonality and nutrient composition of the vegetable by-products. According to the seasonal availability of the agri-food leftovers, three main groups were identified: annual, summer and autumn mixtures, in order to promote the exploitation of the highest quantity of leftovers. This approach allowed the obtainment of statistically reliable correlations (R2 > 0.75) between the employed leftovers and the content of lipid and nitrogen compounds (protein and chitin) of the BSF prepupae. In particular, a mixture of vegetable leftovers available in autumn that included legume (25 wt%), cereal (20 wt%) and vegetable (25 wt%) wastes proved to be the best combination in terms of insect growth (−25% development time compared to the control group) and nutritional composition. The chemical composition of the insect biomass allowed the identification of potential applications with high added value, such as food ingredients (protein and fats) or nutraceuticals (chitin). The identification of the optimal parameters to ensure the greatest possible efficiency would promote the scale-up of BSF rearing to an industrial level.

Experimental investigation on surface behaviour of submerged arc welding fluxes using basic flux system

In present study, the wettability behaviour of basic submerged arc welding fluxes for the CaO–CaF2–SiO2 & CaO–SiO2–Al2O3 welding flux system was studied by measuring the contact angle between the solid/liquid interfaces. Twenty-one submerged arc welding fluxes were formulated using mixture design approach. Contact angle of twenty-one basic fluxes were measured at 1100 °C at constant heating rate. X-ray fluorescence technique was used to evaluate the purity level of individual flux components. Phase analysis and structural properties of different fluxes were determined using Fourier transform infrared spectroscopy & X-ray diffraction technique. Using Young's & Boni's equations different surface tension values for CaO–CaF2–SiO2 & CaO–SiO2–Al2O3 flux systems were determined from measured contact angle value. Dupre's equation was used to find the adhesion energy of the fluxes. Optimum wetting behaviour was observed for lower compositional range (i.e. for CaO/SiO2 & CaO/CaF2 ratio). Flux number 1, 2, 3, 4, 7, 12, 14, 17, 18, 19, 20 & 21 gives higher wettability and spreading area (mm2) due to lower value of contact angle. With increase of CaO/SiO2 ratio there is significant increase in calculated surface tension.

Experimental investigation on high temperature wettability and structural behaviour of SAW fluxes using MgO–TiO2–SiO2 and Al2O3–MgO–SiO2 flux system

To establish the relationship between wettability and structure with the change in SAW flux composition, the contact angle measurement study was performed at 1700 K. For MgO–TiO2–SiO2 and Al2O3–MgO–SiO2 flux system the wetting behaviour was studied by evaluating the contact angle as well as surface tension properties. Sessile drop method was used to determine the wetting properties of SAW fluxes. Twenty-one SAW fluxes were designed & developed by applying mixture design approach of design of experiments. Chemical, phase and structural properties of SAW fluxes were measured using modern techniques such as X-ray fluorescence (XRF), X-ray diffraction (XRD) & Fourier Transform Infra-red spectroscopy (FTIR). As per the calculated contact angle value, different surface tension values for MgO–TiO2–SiO2 and Al2O3–MgO–SiO2 flux system was calculated using Young's & Boni's equations. Using Dupre's equation the adhesion energy for twenty-one basic fluxes was also calculated. Measured contact angle value increased with increase in the TiO2/MgO & TiO2/Al2O3 flux ratio. Lower contact angle gives higher wettability between the flux and the heating substrate. With increase of TiO2/SiO2 ratio up to 1.5 to 2.0 the calculated surface tension value is decreasing while after that it is increased with increase in TiO2/SiO2 ratio.

Incorporation of Sprouted Wheat Seeds as Functional Ingredient in a Mediterranean Breakfast Cereal Based Product, Bsissa: A Mixture Design Approach

Evolution of life style markedly modified people's eating habits. Fortunately, consumers are more aware by the importance of a healthy diet and are more demanding for functional foods. The Mediterranean Diet is a dietary pattern recognized by its positive health effect. However, this diet is disappearing in Mediterranean societies. The aim of this study was to promote a local Tunisian breakfast cereal product by improving its nutritional properties. The methodology consisted on using dried sprouted durum wheat seeds (Triticum durum) as a functional ingredient. The proportion to use without affecting Bsissa functional properties was defined by optimization of a mixture design where the used components were: wheat, dried sprouted wheat and chickpea. The selected responses were water and oil absorption capacity. Based on a mathematical analysis, germinated dried wheat decreased water absorption capacity and had no effect on oil absorption capacity. The optimal formula was composed of: 17.2% wheat, 41.4% germinated dried wheat and 41.4% chickpea. With such composition an increase of +32% in total phenol content and +228.5% in reducing sugar were obtained. However no significant changes on protein content were seen. Interestingly, the use of dried sprouted wheat (not roasted) did not affect the consumers’ acceptance of Bsissa. In conclusion, the use of dried sprouts successfully improved nutritional properties of Bsissa. The use of mixture design approach allowed attempting a balance between functional and nutritional properties.

Design & development of SAW fluxes using CaO–SiO2–CaF2 and CaO–SiO2–Al2O3 flux systems

Physicochemical and thermo-physical behaviour were studied for the agglomerated submerged arc fluxes for CaO–SiO2–CaF2 and CaO–SiO2–Al2O3 flux system. Mixture design approach was used to develop twenty-one fluxes. Thermogravimetric (TGA), differential-scanning calorimetric (DSC), hot-disk technique and XRD techniques were utilized to analyse the fluxes. Structural behaviour of fluxes was analyzed using Fourier transform infrared spectrometer. Thermal behaviour of fluxes was observed in the temperature range of 25 °C to 900 °C. Thermo-physical behaviour such as specific heat, thermal diffusivity and thermal conductivity of each flux were evaluated by hot disc technique. Multi objective optimization was performed to derive the optimized flux formulations. This type of flux formulation helps us to evaluate the physical-chemical and thermo-physical behaviour of different mineral constituents used during submerged arc welding process.