Factorial Central Composite Design Research Articles

Ultrasonic-Assisted Tungsten Inert Gas Welding of Inconel 625 Joints to Reduce Hot Cracking and Improve Microhardness: Optimization and Prediction Methods

Abstract This research article investigated the optimized process parameters for decreasing the hot cracking phenomenon and improving the microhardness of ultrasonic vibratory-assisted tungsten inert gas (U-TIG) welding of Inconel 625 alloy. The study employed two approaches: response surface methodology (RSM) and RSM coupled with a genetic algorithm (RSM-GA). The objective was to analyze the impact of welding process parameters, including welding current, gas flow rate, presence or absence of ultrasonic vibration, and filler material, on the crack length and microhardness of the welded joints. Experimental tests were conducted using RSM with a full factorial central composite design matrix, enabling comprehensive parameter space exploration. Parametric mathematical models were developed based on the obtained experimental data. These models were then utilized as fitness functions within the GA to determine the global optimal solution, aiming to minimize crack length and maximize microhardness. Additionally, artificial neural network (ANN) models were developed to predict the responses and optimize the welding process. The comparison between the experimental and predicted data demonstrated the reliability of the ANN model in accurately estimating the crack length and microhardness of U-TIG welded Inconel 625 alloy joints. The developed models achieved a prediction accuracy of less than 5 % error.

Ultrasound-Assisted Cold Alkaline Extraction: Increasing Hemicellulose Extraction and Energy Production from Populus Wood

Alkaline pretreatments are considered highly effective for the separation of the different components of lignocellulosic biomass. However, cold alkaline extraction (CAE) exhibits minimal modification/degradation of hemicellulosic fraction and successfully accomplishes efficient delignification. In this research, the fast-growing clone AF2 of Populus x euramericana wood was utilized as the raw material and subjected to ultrasound-assisted CAE. The objective of incorporating ultrasound into cold alkaline extraction is to increase the yield of a hemicellulosic-rich liquid phase that can be used to produce high-value products such as furfural or xylitol. Simultaneously, it aims to obtain a solid phase with a higher calorific value compared to the raw material. The results, obtained from a central composite factorial design, demonstrated that the CAE process for 90 min at a sodium hydroxide concentration of 100 g L−1, a temperature of 30 °C, and with ultrasound assistance maximized hemicellulose extraction in the liquid phase (60.8% was extracted) and improved the heating value of solid phase.

Evaluation of Agricultural Soil-Improving Zeolite for Improving Irrigation Water Quality

With a progressively decreasing availability of water for irrigation, the utilization of lower agronomic quality water sources is becoming more prevalent. Compounds such as sodium and boron, due to their impact on crop development and production, are gaining significance in these water sources. Finding novel methods to immobilize these compounds in irrigation water is a top priority in the global agricultural sector. This study focused on exploring the potential of natural zeolite, commonly used as a soil improver and as a sorbent for sodium and boron in natural agricultural waters. The zeolite exhibited favorable properties, including a surface area of 40 m2/g and a cation-exchange capacity of 1.8 mg/g. Using a central composite factorial design, the zeolite’s capacity to remove sodium and boron from irrigation water was investigated. The results demonstrated significant efficiency in boron removal, while sodium removal was limited, with occasional desorption episodes. Response surface analysis revealed optimal conditions for the removal of each cation. Additionally, adsorption kinetics and pH effects were explored, emphasizing the influence on sodium sorption. Kinetic models were applied, and the pseudo-first-order model proved suitable for describing the sorption kinetics. These findings enhance our understanding of zeolite efficacy in irrigation water purification, emphasizing the complexity of cation interactions in “complex” solutions.

Response Surface Methodology Process Optimization of Biodiesel Production from Castor Seed Oil

The increasing demand for energy and the depletion of fossil fuel resources has led to the search for an alternative energy source. The search for such alternative fuel sources has oriented biodiesel synthesis as the ultimate alternative energy resource of the future. The purpose of this study was to produce castor oil and optimize biodiesel production using full factorial central composite design (CCD) through the response surface methodology (RSM) approach. The castor oil was extracted using a mechanical press, and free fatty acids were reduced with acid esterification and biodiesel produced through the transesterification process using homogeneous catalysts. The physicochemical properties of extracted castor oil and biodiesel including density, kinematic viscosity, saponification number, free fatty acid, acid number, cetane number, and iodine number were determined. The ideal conditions for producing biodiesel from castor oil are anticipated to be a reaction period of 105 min at a temperature of 50°C, a catalyst loading weight of 1.5%, and a methanol-to-oil ratio of 5 : 1. The biodiesel yield obtained was 95.0%, and the results of the measured parameters of biodiesel were compared with the international standards of the European norms (EN14214) and the American Society Test Material (ASTM) D6751. The weight composition of both fatty acid and methyl ester was determined by gas chromatography-mass spectroscopy (GC-MS). The study concluded that the results of this research are beneficial in optimizing the parameters for making biodiesel from extracted castor oil.

Study on YB-laser welding applied on aluminum/polymer composites

In the present study, an anodizing process was applied to aluminum alloy (AA2024-T3) to enhance interlocking in dissimilar joints with glass fiber-reinforced polyetherimide (GF/PEI) composite, using ytterbium-doped laser fiber welding as a heat source. A factorial Central Composite Design (CCD) was conducted to determine the most appropriate processing and optimization parameters, with lap shear strength (LSS) as the response variable. The obtained and fractured joints were characterized. Anodizing effectively improved the interlocking between dissimilar joints, resulting in LSS values of around 16 MPa. Surface impressions were observed in joints with lower shear values, likely due to the ineffective heat distribution in the processed joint. In the AA2024-T3 alloy, the annealing process occurred, beginning with the segregation of the alloy elements at the grain boundaries and subsequently reducing its hardness. The SEM analysis of the laminate in the best welding condition revealed a well-established fracture surface, with cusps, fibers covered by the polymer matrix, and river marks, indicating good consolidation of the process applied to the metal/polymer junction, which is consistent with the highest shear values obtained. These findings have important implications for future research and industrial applications and can help advance the understanding of these materials and processes.

Fermentation of biodiesel-derived crude glycerol to 1,3-propanediol with bio-wastes as support matrices: Polynomial prediction model

Biodiesel production from used cooking oil is sustainable alternative, for bio-energy production. The process generates residual crude glycerol (RCG) as the major energy-rich waste which can be used to produce various bio-based chemicals like 1,3-propanediol (1,3-PDO) through biotechnological interventions. This RCG contains several impurities like methanol, soap, organic materials, salts non-transesterified fatty acids and metals in varied concentrations. These impurities significantly affect yield and productivity of the bio-process due to their marked microbial toxicity. In this work, previously isolated Clostridium butyricum L4 was immobilized on various abundantly available cheap bio-wastes (like rice straw, activated carbon and corn cob) to explore advantages offered and improve tolerance to various feed impurities. Amongst these, shredded rice straw was found most suitable candidate for immobilization and results in maximum improvement in 1,3-PDO production (18.4%) with highest porosity (89.28%), lowest bulk density (194.48Kg/m3), and highest cellular biofilm density (CFU/g-8.4 ×1010) amongst the three matrices. For practical purposes, recyclability was evaluated and it was concluded that even after reusing for five successive cycles the production retained to ∼82.4%. Subsequently, polynomial model was developed using 30 runs central composite factorial design experiments having coefficient of regression (R²) as 0.9520, in order to predict yields under different immobilization conditions for 1,3-PDO production. Plackett-Burman was employed (Accuracy= 99.17%) to screen significant toxic impurities. Based on statistical analysis six impurities were found to be significantly influential on PDO production in adverse manner. With negative coefficient of estimate (COE) varying in decreasing order: Linoleic acid >Oleic acid >Stearic acid >NaCl>K2SO4 >KCl. The study illustrates practical application for repurposing waste glycerol generated from biodiesel plants, thus developing improved agnostic process along with yield production models.

One factor at a time and two-factor optimization of transesterification parameters through central composite design (CCD) for the conversion of used peanut oil (UPNO) to biodiesel

This present investigation has optimized the acid and base catalysed transesterification process parameters to enhance the conversion of used peanut oil (UPNO) into biodiesel through a central composite design. Of the different acid and alkali catalysts tested, KOH and H2SO4 were found to be efficient catalysts, which yielded 94.2% UPNO biodiesel. For one factor at a time approach, four reaction parameters such as catalyst dose, reaction time, methanol volume, reaction temperature, and speed of mixing were chosen and a catalyst dose of 1 g and reaction time of 60 min was found to be an independent influential factor to enhance UPNO yield. Therefore, KOH/ H2SO4 catalyst concentration and reaction time were selected to ascertain their synergistic effect on the UPNO biodiesel production through central composite design (CCD). Two factorial CCD design unveils that 1.5 g catalyst (acid and alkali) and 90 min reaction time are the optimal conditions along with 70 °C reaction temperature, 6 mL methanol volume, and 50 rpm stirring speed for high UPNO biodiesel yield of 95.9%. In addition, the fatty acid profile of UPNO biodiesel contains oleic acid and linoleic acid as dominant fatty acids in the range of 55–56 % and 25–27%, respectively in KOH and H2SO4 catalysis. Further, MUFAs, PUFAs, and SFAs levels of UPNO biodiesel produced by H2SO4 catalyst were 55.44, 25.66 and 16.43 %, respectively while they were 56.12, 26.32 and 14.53%, respectively for KOH catalysis. Based on the results of high UPNO biodiesel and MUFA levels, it is contemplated that UPNO biodiesel could be a promising alternative fuel from a commercialization perspective.

Enhancing Concrete Properties Using Silica Fume: Optimized Mix Design

In the current work, concrete mixes containing (7.0-33.11) weight % silica fume as a partial replacement of cement with a water /cement ratio (0.42-0.48) were prepared according to an adopted two factorial central composite design. The samples were tested, optimized, and modeled for compressive strength and density. The estimated results confirmed that compressive strength and density increase with increasing silica fume content up to 11.9 wt.%. Response surface analysis results confirmed that silica fume concrete with developed compressive strength (53.42 MPa) could be prepared by incorporation of 11.9 wt. % silica fume as partial replacement of cement using 0.42 water/cement ratio. An increase in compressive strength and density (up to 39.3% and 2.6% ) respectively was recorded for silica fume concrete mixes compared to Portland cement concrete. Overall, the research findings revealed that silica fume concretes prepared with appropriate silica fume content and water/cement ratio exhibited superior strength and density characteristics candidate them to be used effectively in civil engineering applications.

Effect of co-culturing bacteria and microalgae and influence of inoculum ratio during the biological treatment of tannery wastewater

This present investigation is carried out to study the effect of algal and bacterial inoculum concentrations on the removal of organic pollutants and nutrients from the tannery effluent by the combined symbiotic treatment process. The bacterial and microalgal consortia was developed in laboratory setup and mixed together to perform this study. The Influence of algae and bacteria inoculum concentrations on the removal of pollutants such as Chemical Oxygen Demand (COD) and Total Kjeldahl Nitrogen (TKN) were studied using statistical optimization through Response surface methodology. For the design of experimental set up and optimization, full factorial Central composite design was used. The profiles of pH, Dissolved Oxygen (DO) and nitrate were also monitored and studied. The inoculum concentrations of microalgae and bacteria showed significant effect on Co-culturing on COD, TKN and nitrate removals as major response. The linear effect of bacterial inoculum has positive dominant influence on COD and TKN removal efficiencies. Nitrate utilization by microalgae increases with the increase in microalgal inoculum concentration. The maximum removal efficiencies of COD and TKN with 89.9% and 80.9% were obtained at optimum bacterial and algal inoculum concentrations of 6.7 g/L and 8.0 g/L respectively. These outcomes of this study are immensely favorable for maximizing the COD and nitrogen (nutrients) removal capabilities of microalgae-bacterial consortia in tannery effluent.

A new extracellular glutaminase and urease-free L-asparaginase from Meyerozyma guilliermondii.

L-Asparaginase (L-ASNase) is a potent chemotherapeutic drug employed to treat leukemia and lymphoma. Currently, L-ASNases for therapeutic use are obtained from Escherichia coli and Dickeya chrysanthemi (Erwinia chrysanthemi). Despite their therapeutic potential, enzymes from bacteria are subject to inducing immune responses, resulting in a higher number of side effects. Eukaryote producers, such as fungi, may provide therapeutic alternatives through enzymes that induce relatively less toxicity and immune responses. Additional expected benefits from yeast-derived enzymes include higher activity and stability in physiological conditions. This work describes the new potential therapeutic candidate L-ASNase from the yeast Meyerozyma guilliermondii. A statistical approach (full factorial central composite design) was used to optimize L-ASNase production, considering L-asparagine and glucose concentration, pH of the medium, and cultivation time as independent factors. In addition, the crude enzymes were biochemically characterized, in terms of temperature and optimal pH, thermostability, pH stability, and associated glutaminase or urease activities. Our results showed that enzyme production increased after supplementing a pH 4.0 medium with 1.0% L-asparagine and 0.5% glucose during 75h of cultivation. Under these optimized conditions, L-ASNase production reached 26.01 U mL-1, which is suitable for scale-up studies. The produced L-ASNase exhibits maximal activity at 37°C and pH 7.0 and is highly stable under physiological conditions. In addition, M. guilliermondii L-ASNase has no associated glutaminase or urease activities, demonstrating its potential as a promising antineoplastic agent.

Optimization of Xanthan Gum Production by Demerara Sugar Using Response Surface Methodology

Xanthan gum (XG) production using three Xanthomonas sp. strains (290, 472, and S6) was evaluated by applying a 23 full factorial central composite design response to study the interactive effects of the fermentation medium component concentrations as parameters to determine the efficiency of the gum production in batch experiments. The experimental variables were the carbon source (demerara sugar or sucrose), potassium phosphate dibasic, and magnesium sulfate. Experimental results showed the K2HPO4 concentration as the important parameter for XG production by using Xanthomonas axonopodis pv. manihotis IBSBF 290 and X. campestris pv. campestris IBSBF 472, while for the Xanthomonas sp. S6 strain, the MgSO4∙7H2O concentration was the determining factor in XG production using demerara sugar or sucrose as a carbon source. The strains of Xanthomonas 472 and S6, using demerara sugar and higher concentrations of salts, exhibited a higher yield of XG (36 and 32%) than when using sucrose and the same concentration of salts. The experimental outcomes highlighted demerara sugar as a suitable and efficient alternative carbon and micronutrient source for XG production. Despite the bacterial strain influence, the medium composition is crucial for this fermentation process. Therefore, the evaluated salts are important factors for XG production, and the demerara sugar can partially replace this mineral salt requirement as indicated by the face-centered composite experimental design due to its chemical composition. Overall, demerara sugar provides promising properties for XG production.

Optimization of Ciprofloxacin Adsorption on Clinoptilolite-Based Adsorbents Using Response Surface Methodology.

The adsorption of the antibiotic ciprofloxacin (CIP) from water solution by natural zeolite-clinoptilolite (CLI), magnetic clinoptilolite (MAG-CLI), and graphene oxide coated magnetic clinoptilolite (GO-MAG-CLI) was investigated. The novel approach of an environmentally friendly and cost-effective microwave-assisted method was applied for the magnetic composite synthesis. Detailed characterization of the prepared composites was achieved. In order to investigate the effect of the initial CIP concentration, pH, temperature, contact time, and type of adsorbent on the adsorption efficiency of CIP, and to obtain the optimal conditions for CIP removal, the response surface methodology central composite factorial design (RSM-CCF) was applied. The results obtained by the RSM-CCF showed that among the studied adsorbents, GO-MAG-CLI had the highest adsorption capacity for CIP, achieved for the initial concentration of 48.47 mg dm-3 at a pH of 5 and 24.78 °C after 19.20 min of contact time. The adsorption kinetics studied for the initial CIP concentration range of 15-50 mg dm-3 followed Lagergren's pseudo-second-order model, and the Langmuir isotherm was the most suitable one to describe the CIP adsorption onto GO-MAG-CLI.

EFFECT OF PROCESS VARIABLES ON THE OIL YIELD FROM C.ALBIDUM USING RESPONSE SURFACE METHODOLOGY

Optimization of Chrysophyllum albidum seed oil extraction was carried out in this study. The study demonstrates the prediction capability of response surface methodology for oil extraction from Chrysophyllum albidum seed. RSM based on five levels, three factor central composite design was employed to obtain the best possible combinations of extraction temperature (50-60 oC), extraction time (3-6 hours) and solvent type (hexane and petroleum ether) for maximum oil recovery. A quadratic model was obtained and R2, R, AAD and RMSE were determined to validate the model. The optimum conditions were found to be extraction temperature of 55 oC, extraction time of 6.62 hours with n-hexane a better solvent. For these conditions, oil yield of 12.70% was obtained which is in reasonable agreement with the predicted one. The values of R2, R, AAD and RMSE were calculated as 0.9799, 0.9899, 0.016 and 0.12 respectively. Also the C. Albidum oil obtained was characterized to determine its physicochemical properties. The saponification value and iodine value of 191 and 30.94 respectively indicate that it is suitable for soap, cosmetics, candle and lubricating oil production. The FT-IR also reflects the presence of saturated and unsaturated compounds which makes the oil a potential for biodiesel production.

Design of experiments for the optimization of U(VI) reduction with hydrogen over Pt/SiO2

Abstract Significant amount of uranous nitrate is required for reducing Pu(IV) into inextractable Pu(III) for partitioning of U(VI) and Pu(IV) present in the loaded organic phase in PUREX process. Experiments have been conducted for the preparation of uranous nitrate by reducing uranyl nitrate present in nitric acid solution using hydrogen over Pt/SiO2 catalyst. The effect of process variables such as U(VI) concentration, H2 pressure, nitric acid concentration, catalyst quantity, temperature, mixing speed, and hydrazine concentration (for stabilizing U(IV)) on the yield of U(IV) was studied. The process variables were optimized by a two-step statistical approach namely design of experiments. The initial screening of process variables and determination of important variables that affect the production of U(IV) was determined by definitive screening design (DSD) methodology. The DSD yielded three variables affecting the U(VI) reduction to a significant extent were U(VI) concentration, H2 pressure and mixing speed. These significant variables were further optimized using five-level full factorial central composite design (CCD) methodology for understanding the intricate interactions between the variables and the combined effect of all variables at a time influencing the U(VI) reduction. A second-order polynomial equation derived from CCD was subjected to analysis of variance (ANOVA) for estimating the validity of the model and statistical significance of the terms involved in the polynomial. The results revealed that the model can predict the yield of U(IV) generation with 95% confidence in the proposed experimental range.

Magnetorheological fine finishing of steering rack bar for improving its functional operation

Fine-finished external cylindrical surfaces in automotive manufacturing parts are of great importance for improving their performance. A finely finished external surface of steering rack bar leads to a decrease in its response time. So, in this work, the rotating core-based magnetorheological (MR) finishing process has been performed on the external surface of steering rack bar to improve its performance. In this work, the process parameters have been optimized to fine-finish the current workpiece with minimized efforts. The optimum conditions of process parameters are depicted using full factorial central composite design (CCD) under response surface methodology technique. The maximum contribution to the response, i.e. % change in surface roughness value is found from current (15.28%) and rotational tool speed (8.66%). Using the optimum finishing parameters, the average surface roughness value of the steering rack bar external surface achieved was 30 nm from 550 nm with finishing time of 90 min. Also, the fine finishing of steering rack bar's external surface was confirmed by a comparative study of scanning electron microscopic and mirror images of initial and final finished surfaces conducted in this study. Thus, this study advocated that the current process can be beneficial for fine finishing of industrial components such as rocker arm shafts, vacuum pistons, and cylindrical punches.

Enhancing the Production of the Phenolic Extracts of Asparagus Using an Advanced Green Process.

Asparagus officinalis L. is a common vegetable widely consumed due to its high consumer acceptance. In addition to its flavor, green asparagus contains a high amount of bioactive compounds with health-promoting effects. In this sense, the growing concern of the public health system to promote a diet with a higher consumption of vegetables makes research on phytochemicals from this food of interest. In order to study the content of bioactive compounds from plant matrices, the combination of advanced extraction and analytical techniques within the context of green chemistry is an indispensable working model in today’s research. In the present experimental work, the composition of the phytochemicals of green asparagus from the Protected Geographical Indication (PGI) located in Huétor Tájar, Granada (Spain), was evaluated by environmentally friendly extraction techniques. In order to carry out this work, the recovery of bioactive compounds was evaluated by pressurized liquid extraction (PLE) using GRAS (Generally Recognized As Safe) solvents (mixtures of water and ethanol). The extraction was optimized using a Response Surface Methodology (RSM) based on a 24 factorial Central Composite Design (CCD). The experimental model was followed by high-performance liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (HPLC–ESI-TOF-MS) analytical methodology for a comprehensive characterization. The optimized methodology was compared with conventional solid–liquid extraction protocols using ethanol and water. The results highlighted the potential of advanced PLE techniques compared to conventional systems for the recovery of green asparagus phytochemicals. Moreover, the analytical characterization allowed the identification and quantitation of major phenolic compounds belonging to phenolic acids and flavonoids families. Therefore, an easy, fast, and novel methodology to optimize the extraction of bioactive compounds from green asparagus has been optimized, using Green and GRAS methodology, which enables a better understanding of the bioactive composition of this widely consumed food.

Development and Formulation for the Manufacturing of Coconut Milk Shrikhand

Shrikhand is an indigenous, traditional and fermented dairy dessert of India. The present investigation was carried out to optimize the process of manufacturing coconut milk shrikhand by using coconut milk, cane sugar, and yogurt culture (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) were the variables studied by employing the 3- factors Central Composite Rotatable Design. The formulation with coconut milk shrikhand, was found highly suitable. The desirability index of optimized coconut milk shrikhand.

DEVELOPMENT AND OPTIMIZATION OF ASTRAGALIN-LOADED POLYMERIC NANOPARTICLES USING CENTRAL COMPOSITE FACTORIAL DESIGN

Objective: The objective of the present study was to develop and optimize Astragalin-loaded polymeric nanoparticles (AST-NPs) using a central composite factorial design (CCD). Methods: AST-NPs were prepared by the dialysis method. CCD was employed to study the influence of formulation factors, polymer concentration, aqueous organic phase ratio, and process parameter stirring time on dependent physicochemical characteristics, particle size, zeta potential, and percentage entrapment efficiency (%EE) of the drugs. The optimized formulation was evaluated for in vitro release studies and subjected to stability studies. Results: Polymer concentration and process parameters were optimized to produce nanoparticles with desired parameters. The prepared NPs were characterized by Fourier transmission infrared (FT-IR), differential scanning calorimetry (DSC), drug loading, entrapment efficiency, particle size, zeta potential, and in vitro studies. FT-IR and DSC studies indicated that there was no interaction between the drug and polymer. The optimized NPs exhibits stability. Optimized NPs exhibited spherical and porous surfaces with a mean PS of 118 nm, the zeta potential of-25 mV, and %EE of 89%. Conclusion: Astragalin-loaded nanoparticles prepared with optimized formulation composition and process parameters.

Understanding the interactive effects of dietary leucine with isoleucine and valine in the modern commercial broiler

A study was conducted to understand the relationship among dietary branched-chain amino acids (BCAA) on the performance of Ross 344 × 708 male broilers. A total of 2,592 d-old male chicks were randomly placed into 144-floor pens according to a 23 full factorial central composite design (CCD) with 20 treatments (14 treatments and 6 center points). Each treatment consisted of varying digestible Ile:Lys (52 to 75), Val:Lys (64 to 87), and Leu:Lys (110 to 185) ratios. Birds and feed were weighed at 20 and 34 d of age to determine body weight gain (BWG), feed intake, and feed conversion ratio (FCR). At 35 d of age, feather amino acid composition and carcass characteristics were evaluated. Data were analyzed as CCD using the surface response option of JMP v. 15. Body weight gain (1,332 g; P < 0.001; R2 = 0.93) and FCR (1.54; P = 0.002; R2 = 0.88) were optimized at the lowest Leu:Lys ratio (110) with moderate Val:Lys (78 to 79) and Ile:Lys (65 to 66) ratios. Poorer BWG and FCR were observed as Leu:Lys ratio increased while increasing Val:Lys and Ile:Lys ratios alleviated the poor performance. Carcass (71.5%; P = 0.031; R2 = 0.76) and breast yield (26.7%; P < 0.001; R2 = 0.96) were maximized at the highest Leu:Lys ratio. This effect was complemented by increasing Ile:Lys ratio beyond 68. Lower Ile:Lys and Val:Lys ratios were required to maximize carcass and breast yield at the lowest Leu:Lys ratio. However, this strategy yielded less meat than providing a high Leu:Lys ratio diet. Dietary BCAA had little effect on altering the composition of feather protein and amino acid (P > 0.10). These results suggest that optimum BCAA ratios to Lys may vary depending on response criteria and demonstrate the importance of maintaining proper Val and Ile ratios centered on dietary Leu. Live performance can be optimized in diets with low Leu:Lys ratios; however, meat yield can be enhanced by increasing dietary Leu:Lys along with Ile:Lys ratios.

Tea Tree Oil Nanoemulsion-Based Hydrogel Vehicle for Enhancing Topical Delivery of Neomycin.

The present investigation aims to improve the antimicrobial influence of certain antibacterial drugs, namely, neomycin (NEO), exploiting the benefits of natural oils such as tea tree oil (TTO). Therefore, a distinctive nanolipid formulation, namely, a nanoemulsion (NE), was developed using a Central Composite Factorial Design (CCD) approach depending on the amount of TTO and tween 80 as surfactant. The optimized NEO-NE formula exhibiting minimum globular size and maximum in vitro release was selected. For efficient topical delivery, NEO-NE was incorporated into a pre-formulated hydrogel. The developed NEO-NE-hydrogel was characterized by its physical characteristics such as pH, viscosity, and spreadability. Next, it was tested for stability under different conditions for 3 months. Ultimately, an irritation test was conducted followed by an antibacterial examination. The preparation demonstrated acceptable properties to be successfully applied topically. It showed non-significant changes in stability in both conditions up to 3 months storage when compared to a fresh preparation. It exhibited no irritation when applied on hairless animal skin. Finally, TTO revealed a good inhibition for the bacterial growth that could improve the influence of NEO antibacterial activity, indicating the efficiency of NE containing NEO prepared with TTO to be a promising antibacterial nanocarrier.