Optimal Mixture Research Articles

Prospective reserves of bioactive compounds and their effect on human health: A review on Elaeagnus conferta roxburgh, an edible wild fruit

Fruits are largely consumed throughout the world; they are not only the sources of energy, but also rich in the sources of nutritive compounds, carotenoids, polyphenols, organic acids etc. Fruits provide an optimal mixture of antioxidants such as vitamins, polyphenols, carotenoids along with complex carbohydrate, protein, fat and fiber. Bioactive compounds are molecules with therapeutic potential and have a positive effect on human health and could reduce the risk of numerous chronic diseases. Bioactive compounds are capable of modulating metabolic processes and possess antioxidant, anti-inflammatory, antifungal, antiviral, antibacterial, anticancer, analgesic and hepatoprotective properties both in vivo and In vitro. Epidemiological information substantiates that higher the consumption of fruits, lowers the risk of chronic diseases and fosters good health in humans. The following is a review on Elaeagnus conferta roxburgh fruits prospective reserves of bioactive compounds and their effect on human health.

Influences of high-volume coal bottom ash as cement and fine aggregate replacements on strength and heat evolution of eco-friendly high-strength concrete

This study investigates the potential of using high-volume bottom ash as a supplementary cementitious material (SCM) and fine aggregate replacement in production of high-strength concrete. In the first stage, bottom ash quality was improved by sieving through a No. 50 sieve and grinding to increase fineness. Ground bottom ash (GBA) replaced ordinary Portland cement (OPC) at 35%, 50%, and 65% by weight to produce high-strength concrete. In the second stage, coarse bottom ash (CBA) retained by a No. 50 sieve replaced fine aggregate in an optimum mixture at 20%, 40%, and 60% by volume. Concrete properties including compressive strength, modulus of elasticity, autogenous shrinkage, and heat evolution were evaluated. The economic and environmental impacts of GBA were assessed. The results indicated that concrete with 50% GBA cement replacement could be classified as high-strength concrete at 7 d, achieving a compressive strength of approximately 80.9 MPa at 28 d. Autogenous shrinkage was decreased with an increase in GBA content. The heat evolution of concrete with 50% GBA was decreased by 36.4% compared with the control concrete. Concrete with 50% GBA cement replacement and 60% CBA fine aggregate replacement demonstrated the greatest reduction in autogenous shrinkage and peak of heat evolution, and it was classified as high-strength concrete.

Determination of Optimum Mixture Rate and Cutting Time for Hungarian Vetch and Rye Mixtures

Determination of Optimum Mixture Rate and Cutting Time for Hungarian Vetch and Rye Mixtures

Substantiation of the optimal mix of multi-component pulverulent composition used for laser restoration

The relevance of the stated topic of scientific research is conditioned by the need to obtain qualitative substantiation of the optimal powder mixture with a large number of components, to get the best effect when solving practical problems using methods of laser restoration of working surfaces of parts. This research work aims to justify the optimal structure of a multi-component pulverulent composition for laser restoration of damaged working surfaces of parts. The methodological approach in this scientific research is based on a combination of systematic research of main peculiarities of the process of obtaining high-quality working coating of the part with practical research of possibilities to increase the quality of part coating using pulverulent compositions of many components, which supposes the practical application of a range of research methods to determine real quality parameters of the final coating. In the course of research operations, the results were obtained, that show the possibility of reducing to a minimum the changes in the configuration of the part and the value of its internal stresses, as well as the transfer of necessary characteristics, especially hardness and wear resistance, through the implementation of developed multi-component pulverulent compositions. The results obtained during the investigation of prospects of justification of optimal mix of multi-component pulverulent compositions for laser restoration as well as conclusions formulated on their basis have essential practical importance for workers of chemical and metallurgical industries.

Enhancing the properties of UPOFA-based geopolymer mortar via the incorporation of eggshell ash and silica fume

The aim of this study is to utilize the largest amount of ultrafine palm oil fuel ash (UPOFA) with the incorporation of additives namely eggshell ash (ESA) and silica fume (SF) in the manufacture of geopolymer mortar through the use of a statistical design program (Taguchi). The efficiency of UPOFA source material in the production of geopolymer products has been investigated via four factors, namely the NaOH concentration (moles), Na-silicate: NaOH ratio, eggshell ash (ESA) content, and silica fume (SF) content, where each factor contains three different levels. Each of these factors was examined on three levels in order to obtain an optimal mixture. Nine (9) geopolymer mortar mixtures were prepared according to the proposed [L09 (3 × 4)] matrix by the Taguchi method. The performance of the samples was evaluated by compressive strength, ultrasonic-pulse velocity (UPV), porosity (P%), water absorption (Abs%) and density. The results showed that the optimum mixture consisting of 77 wt% UPOFA, 11.5 wt% of ESA and 11.5 wt% SF, achieved a very high compressive strength of 125.4 MPa after 28 days of curing. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses of the optimized UPOFA-based geopolymer mortar mixture indicated that the properties of the mixture were greatly improved with calcium silicate hydrate (C–S–H) gel as the main binding phases within the synthesized UPOFA-based geopolymer mortar. Therefore, through the production of this geopolymer mortar, a large amount of UPOFA in combination with ESA and SF could be one of the solutions for the environmental and landfill disposal problems in Malaysia, besides promoting greener Portland cement free binder with potentially superior properties and performance.

Anaerobic co-digestion of sewage sludge and Cladophora green algae: Investigation of synergistic effects and Optimization of substrate composition ratio

Anaerobic co-digestion of primary and secondary sewage sludge and <i>Cladophora</i> green algae was investigated under mesophilic temperature conditions. The design of experiment method and the optimal mixture design were used to systematically optimize the substrate composition ratios and elucidate the possible synergistic effects for an anaerobic digestion system. A reduced cubic model was created by Design-Expert software as a function of substrate composition ratios. The model was validated by ANOVA experimentally. Also, the substrate composition ratio's effects on variations in biogas production were studied. All linear impacts on changes in biogas production were significantly observed, and interactions between substrates in combined digestion had synergistic impacts on biogas production rate. The highest amount of biogas (235.17-296.03 ml/g VS) was obtained with ratios of equal to 70-60%, B equal to 0-17%, and C equal to 18-30%. Eventually, the model optimization was performed to predict the optimal conditions to achieve the maximum biogas production rate. It was seen that the predicted and actual values of produced biogas in favorable conditions with an error of about 1.3% are well consistent. The authors conclude that the optimal mixture design can be utilized to assess the optimal composition of substrates in an anaerobic digestion system.

R Shiny App for the Automated Deconvolution of NMR Spectra to Quantify the Solid-State Forms of Pharmaceutical Mixtures.

Bioavailability and chemical stability are important characteristics of drug products that are strongly affected by the solid-state structure of the active pharmaceutical ingredient (API). In pharmaceutical development and quality control activities, solid-state NMR (ssNMR) has proved to be an excellent tool for the detection and accurate quantification of undesired solid-state forms. To obtain correct quantitative outcomes, the resulting spectrum of an analytical sample should be deconvoluted into the individual spectra of the pure components. However, the ssNMR deconvolution is particularly challenging due to the following: the relatively large line widths that may lead to severe peak overlap, multiple spinning sidebands as a result of applying Magic Angle Spinning (MAS), and highly irregular peak shapes commonly observed in mixture spectra. To address these challenges, we created a tailored and automated deconvolution approach of ssNMR mixture spectra that involves a linear combination modelling (LCM) of previously acquired reference spectra of pure solid-state components. For optimal model performance, the template and mixture spectra should be acquired under the same conditions and experimental settings. In addition to the parameters controlling the contributions of the components in the mixture, the proposed model includes terms for spectral processing such as phase correction and horizontal shifting that are all jointly estimated via a non-linear, constrained optimisation algorithm. Finally, our novel procedure has been implemented in a fully functional and user-friendly R Shiny webtool (hence no local R installation required) that offers interactive data visualisations, manual adjustments to the automated deconvolution results, and the traceability and reproducibility of analyses.

Efficient Interrogation of the Kinetic Barriers Demarcating Catalytic States of a Tyrosine Kinase with Optimal Physical Descriptors and Mixture Models.

Computer simulations are increasingly used to access thermo-kinetic information underlying structural transformation of protein kinases. Such information are necessary to probe their roles in disease progression and interactions with drug targets. However, the investigations are frequently challenged by forbiddingly high computational expense, and by the lack of standard protocols for the design of low dimensional physical descriptors that encode system features important for transitions. Here, we consider the demarcating characteristics of the different states of Abelson tyrosine kinase associated with distinct catalytic activity to construct a set of physically meaningful, orthogonal collective variables that preserve the slow modes of the system. Independent sampling of each metastable state is followed by the estimation of global partition function along the appropriate physical descriptors using the modified Expectation Maximized Molecular Dynamics method. The resultant free energy barriers are in excellent agreement with experimentally known rate-limiting dynamics and activation energy computed with conventional enhanced sampling methods. We discuss possible directions for further development and applications.

Use of Municipal Solid Waste Incineration Fly Ash in Geopolymer Masonry Mortar Manufacturing

The feasibility of partially replacing pulverized fly ash (PFA) with municipal solid waste incineration fly ash (MSWIFA) to produce ambient-cured geopolymers was investigated. The influence of mixture design parameters on the compressive strength of geopolymer paste was studied. The investigated parameters included MSWIFA dosage, the ratio of sodium silicate to sodium hydroxide (SS/SH), the ratio of liquid to solid (L/S) alkaline activator, and the ratio of SH molar. A water immersion method was selected as a pretreatment process for MSWIFA, leading to effectively maintaining the volume stability of the MSWIFA/PFA geopolymer. The mixture of 30% treated MSWIFA and 70% PFA with 12 M SS, 0.5 L/S ratio, and 3.0 SS/SH ratio produced the highest three-day compressive strength (4.9 MPa). Based on the optimal paste mixture, category four masonry mortars (according to JGJT98-2011) were prepared to replace various ratios of natural sand with fine recycling glasses. Up to a 30% replacement ratio, the properties of the mortars complied with the limits established by JGJT98-2011. The twenty-eight-day leaching rate of mortars containing 30% MSWIFA was lower than the limits proposed by GB5085.3-2007. Microstructural analysis indicated that the main reaction product was a combination of calcium silicate hydrate gel and aluminosilicate gel.

Assessment and optimization of a novel waste heat stepped utilization system integrating partial heating sCO2 cycle and ejector refrigeration cycle using zeotropic mixtures for gas turbine

A waste heat stepped utilization system integrating a partial heating sCO2 power cycle and a thermally-driven ejector refrigeration cycle is proposed for gas turbine performance enhancement. The gas turbine exhaust heat is stepped utilized by two gas heaters in the sCO2 power cycle and a waste heater. Then, the exhaust CO2 heat is cascade utilized by the ejector refrigeration cycle using zeotropic mixtures (R245fa/R1234ze) as its working fluid. Detailed energy, exergy, and economic models are built to conduct the system performance investigation. The results show that the proposed system can improve the thermal and exergy efficiency by 28.23% and 2.65% compared with the single sCO2 cycle. The parametric study discloses that there are optimal turbine inlet temperature and compressor inlet pressure for power output and optimal refrigerant mixture ratio, around 0.30, for cooling capacity. Further, multi-objective optimization is implemented, and the overall system efficiency, bottoming system exergy efficiency, and levelized cost of exergy can reach 62.15%, 45.22%, and 0.076 $/kWh, respectively. Finally, to prove the superiority of the integrated system for different application scenarios, the system performance is optimized in the gas turbine part-load. The results reveal that the proposed system can effectively improve the gas turbine performance, especially in the part-load. Under all the gas turbine loads, the proposed system's levelized cost of exergy is no more than 0.076 $/kWh, which provides theoretical references for the development of the gas turbine combined system in practical engineering.

An artificial intelligence approach for modeling nachos developed from bhimkol banana (Musa balbisiana) blossom

AbstractThe study comprises the investigation of nutrition, phytocomponents, antioxidant activities, antibacterial activities, formulation, and optimization of nachos from underutilized bhimkol (Musa balbisiana) blossom by metaheuristic approach: optimal mixture designed artificial neural network coupled with particle swarm optimization (ANN‐PSO). The overall acceptability (OA) obtained from the sensory evaluation was taken as the output layer of the swarm optimization. Investigation showed bhimkol blossom (BB) as a good source of nutrition, phytocomponents such as carbohydrate (66.87 ± 0.20%), crude fiber (12.12 ± 0.28%), vitamin E (8.73 mg/g), and fatty acid consisting of monounsaturated (66.67%) and polyunsaturated (33.33%). The whole blossom showed the highest antioxidant at 82.77% in the 2,2‐diphenyl‐1‐picrylhydrazyl assay and major antibacterial activity against Salmonella typhi at IC50 25.21 ± 0.14 mg/ml. The optimum set of the parameter from ANN‐PSO for best nachos was obtained at OA of 8.9 in epoch 6 and showed high fracturability and crispiness. Principal component analysis among the sensory attributes of commercial, control, and BB nachos revealed that the taste and OA were majorly weighted towards component 1. The least significant difference was found between commercial and BB nachos. Nutrition rich nachos can be helpful in worldwide implementation in commercially profitable food industries.Practical ApplicationsUnderutilized wild bhimkol blossom (BB) is rich in nutrition, and phytocomponents along with significant antioxidant and antibacterial properties. The modeling of nachos by particle swarm optimization resulted in optimum set of parameters corn starch, wheat flour, BB, refined oil, and black pepper at 0.13, 0.39, 0.33, 0.66, and 0.26 g, respectively. Overall acceptability was positively affected by increased wheat flour exhibiting high fracturability and crispiness. This nutritious new product may possess other tremendous health benefits and have high consumer demand leading to profitable micro‐large food industries. This is also a sustainable approach to environmental loss and utilizing something demanding and good consumer acceptability.Novelty StatementUnderutilized wild bhimkol blossom is rich in nutrition, and phytocomponents along with significant antioxidant and antibacterial properties. Overall acceptability was positively affected by increased wheat flour exhibiting high fracturability and crispiness. This nutritious new product may possess other tremendous health benefits and have high consumer demand leading to profitable micro‐large food industries with excellent consumer acceptability.

Optimization of antibacterial activity of essential oil mixture obtained from three medicinal plants: Evaluation of synergism with conventional antibiotics and nanoemulsion effectiveness

• Mixture design of L. maroccana, T. vulgaris and A. leucotricus were established. • Synergistic interactions were recorded and optimized EO mixture was defined. • Optimal mixture decreased the antibiotics MICs by 2- to 64-fold. • Optimized EO mixture showed high antibacterial effect in nanoemulsion. The present study aimed to optimize the antibacterial activity of essential oil (EO) mixture obtained from Ammodaucus leucotrichus Cosson, Thymus vulgaris L. and Lavandula maroccana (Murb.) against three multi-drug resistant bacteria, using augmented simplex-centroid design. GC–MS analysis showed that A. leucotrichus EO was characterized by the abundance of l -perillaldehyde (50.39%), d -limonene (21.61%) and bornyl angelate (7.09%). T. vulgaris EO was dominated by thymol (42.34%), p -cymene (19.71%) and γ-terpinene (11.50%), while carvacrol (71.62%) represents the main component of L. maroccana EO. Regarding antibacterial assays, individual EOs displayed moderate activity with MIC and MBC values ranging from 0.06% to 5.00%, while the coefficient terms of the different tested combinations revealed synergistic interactions. The results of predicted optimization showed that the optimal EOs mixture composed by 55% of T. vulgaris, 41% of L. maroccana and 4% of A. leucotrichus, significantly decreased the MICs against Staphylococcus aureus (0.0225%), Escherichia coli (0.05%) and Pseudomonas aeruginosa (0.688%). The optimal mixture exhibited a significant decrease in the MICs of gentamicin (4-fold) and amoxicillin (2- to 64-fold), and achieve the highest antibacterial effect in nanoemulsion formulation. The optimized EO mixture based on the studied plants should be considered as a potential alternative to control foodborne, and resistant bacteria.

New Experimental Vapor-Liquid Equilibria Data and Thermodynamic Modelling for R1234yf/propane/R32 as low-GWP Mixtures in Heat Pump Applications

This paper presents new experimental results for the Vapor – Liquid Equilibria of binary mixtures of R1234yf and propane at 277 and 313 K. The newly collected data are then used, in combination with other existing data retrieved from the literature, to calibrate the Peng-Robinson Equation of State with suitable accuracy for domestic vapour compression heat pump cycles simulations. After calibration, the Equation of State is applied to numerical simulations, in Aspen Plus, aimed at finding the optimal refrigerant composition, among ternary mixtures containing R1234yf, propane and R32. Results identify a Pareto curve where the optimal mixtures (with flammability lower or equal to A2L and GWP < 500) are represented in terms of two contrasting objectives: COP and the volumetric heating effect. Ternary mixtures containing propane and R1234yf respectively in the range 0÷12%mass and 18÷30%mass are Pareto optimal: the mixture with the best COP (2.7% lower than R410A one) is the binary pair R32 = 70% + R1234yf = 30%, a composition very close to the one of the commercial refrigerant R454B. On the other hand, the mixture with the largest volumetric effect (6.5% higher than R410A one) is the ternary blend R32 = 70% + R1234yf = 18% + propane = 12%. This study confirms that is quite challenging to find R410A replacements featuring at the same time reasonable heating capacity and a COP not lower than R410A one.

Analysis of oil mixing for improvement of biodiesel quality with the application of mixture design method

The study aims to improve biodiesel's fuel quality using optimal oil mixture. Four oils, namely, Karanja, Jatropha, Palm and Waste cooking oil(WCO) were selected and their mixtures were prepared. A simplex lattice mixture design model for biodiesel properties (Kinematic viscosity(KV), Density, Cetane number(CN) and Oxidation stability(OS)) was developed and optimisation of oil mixtures was conducted. Biodiesel fuel properties of the optimum ratio of the mixture of Karanja:Palm oil (51.6:48.4% v/v) are found as KV(3.854 mm2/s), density (860 kg/m3), CN(56.189), and OS (9.565 h), thereby, indicating that the OS of the biodiesel of optimum mixture is improved by 21.47% and CN by 4.2% compared to Karanja biodiesel. Jatropha oil biodiesel does not meet the biodiesel standard (EN 14214), but when mixed with Palm oil in an optimal ratio of 34.8:65.2% v/v (Jatropha:Palm), biodiesel from this optimal mixture obtained are KV(3.822 mm2/s), density(869.95 kg/m3), CN(55.69) and OS(8.16 h) found. So mixing oils improve the biodiesel OS by 46.9% and CN by 11.28% and also satisfies biodiesel standards compared to individual Jatropha oil biodiesel. However, no optimum ratio for the mixture of WCO with Jatropha or Karanja was found suitable for converting biodiesel that can fulfil biodiesel standards.

ANALYSIS OF THE TEMPERATURE INFLUENCE OF FRESH ASPHALT MIXTURE ON THE NUMBER OF ROLLER CROSSINGS

In the construction of new roads in BiH, reconstruction or rehabilitation of existing roads, construction or replacement of asphalt layers is a mandatory part of construction work. One of the most important characteristics of the asphalt mixture during installation is the temperature of the asphalt mixture. Legal regulations, ie technical conditions, define the minimum temperature of the asphalt mixture as well as the limit air temperatures during the installation of asphalt, but special emphasis is given to the optimal temperature of the asphalt mixture. The optimal temperature of the asphalt mixture in this paper was analyzed through the compaction property of the asphalt mixture. Therefore, working on several specific examples, observes the optimal temperature of the asphalt mixture so as to obtain the best possible compaction of the installed asphalt. During the research, numerous other data that are important for the research were measured, such as the number of roller crossings, roller weight, air temperature, etc. Keywords: asphalt mixture temperature, installation, asphalt compaction, roller

CONTROL OF CORN POLLUTION IN THE CONDITIONS OF THE RIGHT-BANK FOREST STEPPE

This article presents the results of studies of the main elements and methods of controlling the development of weeds in corn crops and the identified changes in water and nutrient properties of the soil. The optimal tank mixtures and technological combinations of new soil and insurance herbicides have been determined, which provide a high level of technical efficiency on a wide species spectrum of weeds that clog corn crops. In particular, for farm conditions, the complex nature of the formation of the type of weediness, which changes during the growing season of the crop, was noted. The results of assessments of the dynamics of weed vegetation indicate a gradual increase in cenotic tension due to the gradual transition of dominant species of weeds, such as Chenopodium album L., Amaranthus retroflexus L., Echinochloa crus-galli L., Elytrigia repens (L.) Gould , Sonchus arvensis L, Cirsium arvense L., Convolvulus arvensis L. in the middle tier of sowing with a simultaneous increase in the frequency of their determination by 1.1-1.3 times. It was established that the best growth and development of the total leaf surface of corn plants (2.15-2.26 pcs./m2) was noted on the herbicide agro background and complete removal of weeds, and with natural weediness of the crops - a negative effect on growth processes, size and duration of functioning of leaves (1.14 pcs./m2). According to the research results, the technical efficiency against weeds of the first wave reached 100% when combining soil and insurance herbicides - Dual Gold - 1.5 l/ha (before sowing) + Stellar - 1.25 l/ha + Surfactant Metolate - 1.25 l/ha (by stairs); during the second and subsequent waves of weeds, protection systems that combine vegetative and soil deterrent effects are best controlled (Stellar - 0.8 l/ha + Akris - 1.5 l/ha + Surfactant Metolate - 0.8 l/ha and Kelvin Plus - 0.3 kg/ha + Akris - 1.5 l/ha + PA Hasten - 1 l/ha). The highest yield of corn grain (6.98 t ha-1 and 6.81 t ha-1) was obtained from the combination of soil and insurance preparations Akris (before sowing) + Kelvin Plus and PAR Hasten (after the steps) and Dual Gold (before sowing) + Stellar and surfactant Metolat (by stairs); Akris + Stellar + metolat surfactant (yield - 6.68 t ha-1) was singled out among post-emergence herbicide mixtures; with autonomous use of the preparations Stellar and Kelvin Plus, the yield was 6.35 t ha-1 and 6.22 t ha-1, respectively. The identical economic expediency of using such variants of herbicide application on corn Akris, 1.5 l/ha + Stellar, 0.8 l/ha + Metolat surfactant, 0.8 l/ha and Stellar, 1.25 l/ha + Metolat surfactant, has been confirmed ,1.25 l/ha, which was 43% higher than in the control with natural weeding and 33.2-33.4% higher than in the option of inter-row cultivation with manual weeding.

Consolidated Drained Triaxial Test on Treated Coastal Soil and Finite Element Analysis Using PLAXIS 2D

Coastal areas are susceptible to erosion and accretion; therefore, coastal soil mechanical properties and ability to withstand loads are important factors to consider. Coastal erosion is inevitable as the sand and silt particles move inexorably from place to place. This study investigates the primary consolidation behaviour of treated coastal soil by comparing the empirical data obtained from triaxial tests based on analytical calculations and FEM software, PLAXIS 2D. The aim is to propose an optimum mixture to improve coastal soil’s geotechnical properties, especially in shear strength and stiffness. Two different material models, including lime/RHA and cement/RHA, were utilized to compare the performance of advanced constitutive treated soil samples against the Mohr–Coulomb material model. 8% lime and rice husk ash (portions of 1 : 2) were chosen to be replaced with cement, as an application of waste material can reduce the cost and environmental impact. All the triaxial tests were conducted at effective confining pressures of 50 kPa, 100 kPa, and 200 kPa. While using PLAXIS 2D, the asymmetrical condition for modelling the triaxial test and 15 nodded triangular elements, as well as the Mohr–Coulomb model for soil properties, are used to simulate the empirical data to verify this study’s effectiveness. The modelling of 2-dimensional drain behaviour involves setting out the model geometry and boundary conditions. The results revealed that the deviatoric stress and volumetric changes of LRHA increased in a range of 4.5 to 5.2% and 72.18 to 141.79%, respectively, as compared to CRHA. The FE analysis results for peak deviator stress values reasonably agree with the experimental results. The variation was in the range of 1.22% to 4.10%. Eventually, the treated soil’s peak and maximum shear strengths are reported to allow flexible use in future projects.

Shear Behavior of Granulated Blast Furnace Slag-Based Geopolymer-Reinforced Concrete Beams

Active research is ongoing regarding the mechanical behavior of structural members manufactured from geopolymer concrete (GC), as it lacks standardized/codified manufacturing and design procedures. This study aims to address the shear behavior of GC beams. First, a consistent trial–error-based approach was used to develop the optimal mixture ratio (102.38/234.0 for NaOH/Na2SiO3) in terms of workability and consistency for the production of six (6) test specimens with span-to-depth ratios of (a/d) of 2.5, 3.5, and 4.5 and transverse reinforcement intervals of 10, 15, and 20 cm. Then, shear failure tests using a three-point bending setup were conducted and analyzed statistically. As a first attempt in the literature, an empirical expression for shear capacity prediction that was specifically tuned for GC beams was given. This expression, along with seven other similar expressions for ordinary concrete beams from the literature, and various practice codes were tested against a pool of experimental shear failure results given by four (4) different researchers. As a measure of the predictive capability, coefficient of variation (COV = standard deviation/average) values were obtained, and the lowest COV value of 0.305 suggested that the expression obtained the highest predictive capability, whereas more common practice codes such as ACI318, EN1992, and ENV1992 produced COV values of 0.435, 0.374, and 0.627, respectively. Finally, this study provides a working expression for the shear capacity estimation of GC beams and a mixture ratio for the practical manufacturing conditions of workability and consistency, with a slump value of 270 mm and a 90 min setting time.

Optimization of Chlorella vulgaris cultivation grown in waste molasses syrup using mixture design

AbstractThe aim of this study was to determine and optimize culture media for Chlorella vulgaris microalgae under mixotrophic conditions using waste molasses as a cheap carbon source containing both organic carbons and other nutrients. In the current study, at first the growth and lipid productivity of C. vulgaris were assessed in different culture media and the best media was selected for mixotrophic growth conditions. Significant medium ingredients were screened through Plackett–Burman design. Then ingredients with positive effect were considered as a mixture component and their combinations were evaluated on lipid productivity using mixture design. According to results, Zarrouk medium was considered as the base medium with the highest biomass and lipid productivity of 72 and 7.1 mg L−1 d−1, respectively. Based on the Plackett–Burman design, out of 11 factors, molasses, NaNO3 and K2HPO4 demonstrated key roles in biomass and lipid productivity in mixotrophic conditions. Consequently, the selected three factors were investigated by mixture design. The results showed that high concentration of molasses causes decrease in biomass and lipid productivity due to high turbidity and a blend consisting of approximately 9.5 g L−1 molasses, 5 g L−1 NaNO3 and 0.15 g L−1 K2HPO4 was found as the optimum mixture with obtained lipid productivity of 115 mg L−1 d−1. In conclusion, waste molasses can be used as a promising feedstock for cost effective cultivation of C. vulgaris.

Study on Tensile Properties of Fly Ash, Sugarcane Fiber and Carbon Nanotube-Reinforced Polymer Matrix Composite Using Objective Evolutionary Algorithm.

Composite materials have a wide range of applications in emerging eco-friendly environments. Composites that created from naturally available materials are easily decomposed over time and very cost-effective. Fly ash and sugarcane fiber are widely available waste materials produced on a massive scale. This research was aimed to find an optimal mixture of reinforced composites (fly ash, sugarcane fiber and CNTs) in order to maximize yield strength, ultimate tensile strength and Young's modulus using a Multi-Objective Evolutionary Algorithm with Decomposition (MOEA/D). Optimizing one objective may have a negative impact on another objective, so the authors used the sophisticated MOEA/D algorithm to simultaneously find optimal values on all three objectives. The Design of Experiments (DOE) method was performed using ANOVA, and then regression equations were generated. The regression equations were optimized using the MOEA/D algorithm to obtain optimal values. Using the optimal compositional values produced by the algorithm, materials were fabricated. The fabricated materials were tested using a Shimadzu UTM machine to cross-validate the findings. A combination of 0.2 wt.% of fly ash, 2 wt.% of SCF, and 0.39 wt.% of CNTs showed a maximum yield strength of 7.52 MPa and Young's modulus of 1281.18 MPa, with a quite considerable ultimate tensile strength of 10.54 MPa compared with the optimized results obtained through the response surface methodology.