Search Results (2,029)

In this study, the capacity of the ubiquitous filamentous fungus Penicillium sp. 8L2 to remove Zn(II) ions present in synthetic solutions was studied and the optimal operating conditions were obtained based on a response surface methodology (RSM). The contact time was optimized through kinetic tests. Equilibrium tests were then carried out, which allowed biosorption isotherms to be obtained for several mathematical models. At the same time, the capacity of the fungal cell extract to transform metal ions into ZnO nanoparticles with a biocidal capacity was evaluated. Its inhibitory capacity for five microbial strains was then determined. The biosorption mechanisms and nanoparticle synthesis were characterized by different crystallographic, spectrophotometric and microscopic analytical techniques. It was confirmed that the metal was bound superficially but also in the periplasmic space with a strong bond to phosphate groups, both in the biosorption stage and during the synthesis and consolidation of the nanoparticles. In addition, the presence of hydroxyl, amino, carbonyl and methylene groups was identified, which could promote the synthesis of nanoparticles, since some of them have a reducing nature. The kinetics showed that the biosorption of Zn(II) occurred in two stages, the first very fast and the second slower. Equilibrium tests identified a maximum biosorption capacity of 52.14 mg/g for the Langmuir model under optimized conditions: a contact time of 5 days, pH 5.6 and a 0.2 g/L biomass dose. The success of the biological synthesis route was confirmed and ZnO nanoparticles with an average size of 18 nm were obtained. The data showed that the nanoparticles showed a good inhibition ability against the tested microorganisms, with values ranging from 62.5 to 1000 µg/mL. Penicillium sp. 8L2 is a promising ubiquitous microorganism in the field of heavy metal biosorption and applied biotechnology. Full article

This work presents biodiesel production using waste margarine oil and response surface methodology (RSM) for optimisation. The transesterification of waste margarine oil was carried out using sodium hydroxide (NaOH) as a catalyst under atmospheric pressure in a lab-scale batch reactor. Central composite design (CCD) was used to optimise four parameters: methanol-to-oil ratio (3–15 mol/mol), catalyst ratio (0.3–1.5 wt.%), reaction time (30–90 min), and reaction temperature (30–70 °C). Numeral optimisation was performed, and an optimum yield of 99.1% was obtained at an 11.906 methanol-to-oil mol ratio, 1.113 wt.% catalyst ratio, 59.646 min reaction time, 52.459 °C temperature, and a low percentage error yield of 0.942%. Analysis of variance (ANOVA) showed that the methanol-to-oil ratio had the highest influence on the biodiesel yield, followed by the catalyst ratio, and reaction time had the least impact after temperature. The kinetics study revealed that the reaction is controlled by a pseudo-first order, and the activation energy was found to be 62.41 kJ/mol. It was concluded that biodiesel could be produced using waste margarine oil as a cost-effective feedstock optimised by RSM. Full article

Background: Indonesia is an archipelagic country with 17,508 islands spread over the Pacific and Indian Oceans, with thousands of inter-island routes requiring a large and engaged fleet. The vast expanse of the country also leads to challenges related to optimal fleet coverage, routing, and oil distribution while maintaining cost-effectiveness and reliable supply. Methods: This study combined a mixed-integer linear-programming (MILP) model with a response surface methodology (RSM) approach to optimize vessel assignment, vessel routes, and inventory control simultaneously and comprehensively across three regional clusters (i.e., Western, Central, and Eastern Indonesia). The model takes into account a fleet of 28 vessels (13 medium range [MR] and 15 general purpose [GP]) that can distribute three oil products: gasoline, diesel, and kerosene. Results: The optimized solution yields 100% service reliability at an operational cost of $ 2.83 million per month—far lower than currently operating services. The model is robust against variations in demand (±20%), port congestion (±50%), and changing fuel prices (±50%), which is confirmed by a sensibility analysis. The close correlation coefficient (0.987) between the MILP and RSM results confirms the framework’s accuracy. At the same time, the critical performance factors were found to be vessel speed (13.5 knots), fleet size, and port operation time. Conclusions: The study offers a cost-efficient and data-intensive model that could be implemented as a maritime logistics framework, as well as potential areas for future work and insight for relevant stakeholders. Future research will have to integrate real-time data fusion, mainly due to the need for environmental and stochastic modeling methods to foster operational resilience in dynamic maritime business ecosystems. Full article

This study focused on improving the mechanical properties of hemp-fiber-reinforced epoxy (HFRE) composites by modifying the surface of hemp fibers (HFs) using dielectric barrier discharge (DBD) plasma treatment. By exposing the fibers to different gas mixtures Ar, Ar+N₂, and Ar+O₂, the surface of the fibers was altered, adding functional groups, increasing surface roughness, and improving crystallinity. The researchers created HFRE composites using both untreated and plasma-treated HF, and then tested their mechanical properties. The results revealed that Ar+O₂ plasma treatment boosted both the tensile strength (by 15.2%) and energy absorption of the composites. To fine-tune the process, the response surface methodology (RSM) was used to determine the most important factors for optimizing the treatment: input power and treatment time. The ideal conditions were found to be 162.63 W of power and 10 min of treatment. These findings highlight the potential of DBD plasma as a reliable method for modifying the surface of hemp fibers, even with changes in the setup or reactor design. Overall, this approach shows great promise for industrial applications, providing an effective way to improve the strength and durability of HFRE composites for a variety of uses. Full article

Background: Opuntia ficus-indica (OFI) cladodes are valuable and underestimated by-products that provide significant amounts of biologically active compounds. In this paper, microwave-assisted extraction (MAE) was performed for the recovery of phenolic compounds from OFI cladodes using two approaches: response surface methodology (RSM) and artificial neural network–genetic algorithm (ANN-GA), which were then compared following statistical indicators. Materials and Methods: Four independent factors were employed in the optimization process (solvent concentration, microwave power, irradiation time, and solid-to-liquid ratio) by selecting the total phenolic content (TPC), estimated by the Folin–Ciocalteu method, as a response. The optimized extract was tested for antioxidant capacity using the Folin–Ciocalteu reagent, Trolox Equivalent Antioxidant Capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays and for antimicrobial activity against 16 pathogenic strains using the agar well diffusion method. Results: The maximum TPC values predicted with maximizing desirability function for RSM were 2177.01 mg GAE/100 g DW and 1827.38 mg GAE/100 g DW for the ANN. Both models presented certain advantages and could be considered reliable tools for predictability and accuracy purposes. Using these conditions, the extract presented high antioxidant capacity for FCR assay (13.43 ± 0.62 mg GAE/g DW), TEAC (10.18 ± 0.47 µmol TE/g DW), and ORAC (205.47 ± 19.23 µmol TE/g DW). The antimicrobial activity of the optimized extract was pronounced only with respect to S. aureus alimentarius, Streptococcus, E. coli, P. aeruginosa, and A. flavus. Conclusions: This study underlines the high effectiveness of the optimization approaches in providing a maximum recovery of bioactive compounds from OFI cladodes to formulate food and pharmaceutical products with functional qualities. Full article

In this study, we aimed to optimize the process of extracting essential oils from Ligusticum jeholense Nakai et Kitag. vegetables (LJ-Vs) by means of hydrodistillation (HD), analyze the essential oils’ chemical composition, and evaluate their antioxidant and antibacterial activities so as to provide a certain research basis for their development and utilization. A single-factor test and the response surface methodology (RSM) were used to optimize the essential oil extraction process. The chemical constituents of the LJ-V essential oils were analyzed via GC-MS, and the antibacterial and antioxidant activities of the oils were studied. The optimal extraction process conditions were as follows: a solid–liquid ratio of 1:16.3 g/mL, a soaking time of 120 min, and crushing using a mesh size of 40. The validation result for the optimized process was 0.872%. A total of 32 chemical components were detected in LJ-V essential oils, among which the main components were neocnidilide, myristicin, elemicin, and germacrene. LJ-V essential oils with a 20% volume concentration had obvious inhibitory effects on four tested bacteria. The effect on Staphylococcus aureus was stronger than that on others. When the dilution concentration exceeded 100 times, the antibacterial effect was not ideal. The sensitivity of the tested bacteria to the essential oils followed the order Staphylococcus aureus > Salmonella > Pseudomonas fluorescens > Escherichia coli. Further, LJ-V essential oil had an ideal capacity to scavenge free radicals when compared to Vc control groups. Under the optimized conditions, the essential oil extraction rate was higher, and the process was stable and feasible. This study could provide theoretical and technical support for the cultivation, comprehensive development, and processing of Ligusticum jeholense Nakai et Kitag. resources. Full article

This research sought to explore the impact of ultrasonic pretreatment on the physicochemical characteristics of proteins derived from eggshell membranes through enzymatic extraction. Response surface methodology (RSM) and Box-Behnken design were employed to identify the ideal conditions for the extraction process. The optimal parameters determined were enzyme usage at 4.2%, pH level at 2.4, a solid-to-solvent ratio of 1:20 g/mL, and an extraction time of 21.5 h. The eggshell membrane was pretreated by ultrasound before pepsin hydrolysis under optimized conditions. The findings indicated that the hydrolyzed products subjected to ultrasonic pretreatment exhibited enhanced solubility, surface hydrophobicity, water and oil retention, foaming characteristics, and emulsifying ability compared to the untreated hydrolyzed products. Furthermore, the piezoelectric properties of the protein with ultrasonic pretreatment were also significantly improved. Additionally, the protein-based piezoelectric device displayed excellent sensing performance and was successfully applied for human motion detection and precise identification of different pressure positions. These findings indicate that ultrasound has great potential to improve the physicochemical quality of eggshell membrane proteins, providing a theoretical basis and research approach for food protein modification and the preparation of green electronic devices. Full article

The improvement of PBF manufacturing accuracy has been an urgent problem to solve. The columnar-to-equiaxed transition of rapid solidification during laser powder bed fusion (L-PBF) has been reported, while its influence on the accuracy and surface roughness of fabricated 316L micro-lattice structures remains to be studied. This study presents a novel fully coupled finite volume method for cellular automata (CA), integrated with response surface methodology (RSM), which is applied to investigate the columnar-to-equiaxed transition influence on the accuracy and surface roughness of ultra-precision additive manufactured 316L lattice structure by L-PBF. It is proven that the higher overlap is identified as the optimal strategy for improving both surface quality and dimensional accuracy. Both the CA model prediction and the experimental results reveal that the effect of latent heat releases from the grain refinement on the adhesion of the surrounding powder is an increment of the surface roughness, while the decrement of the surface quality and accuracy. The overlap strategy is promoted to be the most suitable measure to achieve both high surface quality and manufacturing accuracy. The surface roughness Ra (SP) can rapidly decrease by 68.6%, and the mean diameters decrease by 18.7% under the overlap strategy. Full article

Medical and aromatic plant extracts are often very sensitive to environmental, gastrointestinal, and processing conditions despite their health benefits. Therefore, they can be rapidly inactivated. Microencapsulation is used to overcome such challenges. In this study, phenolic antioxidants from rosemary (Rosmarinus officinalis L.) were encapsulated in alginate beads by means of ionic gelation. A Box–Behnken design with response surface methodology (BBD–RSM) was used with three numeric factors (calcium chloride concentration, alginate concentration, and hardening time) to achieve the best formulation in terms of encapsulation efficiency, antioxidant activity, and morphological characteristics. Generally, the sodium alginate concentration of the microbeads was the most critical factor (p < 0.0001) for the quality of the products. The optimal encapsulation conditions were accessed using concentrations with almost 6% calcium chloride and 2% alginate, and a time of 10 min for bead hardening in order to obtain the highest responses (30.01% encapsulation efficiency, 7.55 mg-TEAC/g-DM of antioxidant activity value as measured by the DPPH method, a sphericity factor of 0.05, and a roundness of 0.78). At the optimum point, the microbeads were determined to be spherical in shape, and the bulk density value was measured as 0.34 ± 0.01 g/mL. Full article

This study posits that strategically optimizing irrigation and fertilization regimes can enhance the productivity and water use efficiency (WUE) of alfalfa (Medicago sativa L.), thereby mitigating the constraints imposed by soil impoverishment and water scarcity in forage production systems of arid and semi-arid regions. Conducted over two years, the outdoor pot experiment investigated the effects of water regulation during the branching and bud stages (each at 60–100% θ_0.85, where θ_0.85 = 0.85θfc) and different levels of nitrogen and phosphorus fertilization (0–280 kg/ha each) on alfalfa yield and WUE. Using Response Surface Methodology (RSM) with a Central Composite Design (CCD), we modeled the relationships between input variables and key response parameters: total yield, evapotranspiration (ET), and WUE. The response surface models exhibited high reliability, with coefficients of determination R², adjusted R², predicted R², and adequate precision exceeding 0.94, 0.90, 0.86, and 13.6, respectively. Sensitivity analysis indicated that water regulation during critical growth stages, particularly the branching stage, had the most significant impact on yield and ET, while nitrogen and phosphorus fertilization positively influenced WUE. Within the appropriate range of water management, judicious fertilization significantly enhanced alfalfa production performance, although excessive inputs resulted in diminishing returns. This study identified the optimal conditions for sustainable production: branching stage water regulation (82.26–83.12% θ_0.85) and bud stage water regulation (78.11–88.47% θ_0.85), along with nitrogen application (110.59–128.88 kg/ha) and phosphorus application (203.86–210 kg/ha). These findings provide practical guidelines for improving the sustainability and efficiency of alfalfa production in resource-limited environments. Full article

Grape pomace is a by-product abundant in phenolic compounds that can be used in the food, cosmetic, and pharmaceutical industries. For the efficient extraction of such compounds, an aqueous solution of non-ionic surfactant Brij S20 was applied as a green extraction medium, and the optimization was performed using surface response methodology. The effects of four independent factors (surfactant concentration, time, pH, and solvent-to-material ratio) were evaluated, and total phenolic content (TPC), DPPH radical inhibition, and selected polyphenol compound concentrations were analyzed as responses. Using response surface methodology (RSM), five regression equations were derived and good adequacy of the models was confirmed. The solvent-to-material (SM) ratio was the most influential factor. Surfactant concentration of 3% (m/V), extraction time of 120 min, pH value of 4.06, and SM ratio of 50 mL/g were determined as optimum conditions to maximize all responses. Under the optimal conditions, the mean validated values obtained for TPC, DPPH, gallic acid, catechin, and quercetin concentrations were 968.50 ± 37.06 mg GAE/L, 61.41 ± 7.13%, 5.10 ± 0.05 mg/L, 10.62 ± 0.79 mg/L, and 6.04 ± 0.10 mg/L, respectively. Furthermore, the established conditions were applied for the extraction of phenolic compounds from grape pomace of four grape varieties. The proposed extraction method proved effective, providing extracts rich in polyphenols suitable for further applications. Full article

Urbanization necessitates Low Impact Development (LID) practices for sustainable development, but existing studies lack analysis about the comprehensive effect and optimal allocation of LID combination practices. To address this gap, this study conducted an in-depth analysis of the runoff control effects of individual and combined LID practices and pollutants under varying retrofit proportions, utilizing the Storm Water Management Model (SWMM). Four evaluation metrics were employed for parameter calibration and validation assessment to ensure the accuracy of the SWMM. The Response Surface Methodology (RSM) was then employed to optimize the retrofit proportions of LID practices due to its high efficiency and statistical rigor. The results showed that, under the same retrofit ratio, bio-retention (BC) has a better runoff reduction rate and pollutant removal rate. For example, when the retrofit proportion is 100%, the runoff pollutant removal rates of BC in Parcel 1 and Parcel 2 are 29.6% and 32.9%, respectively. To achieve a 70% runoff control rate, the optimal retrofit proportions for Parcel 1 were 67.5% for green roofs (GR), 92.2% for permeable pavements (PP), 88.9% for bio-retention cells (BC), and 50% for low-elevation greenbelts (LEG); these correspond to the proportions for Parcel 2 that were 65.1%, 68.1%, 82.0%, and 50%, respectively. In conclusion, this study provides scientific and technical support for urban planners and policymakers in urban rainwater management, especially in similar regions. Full article

Background/Objectives: Melanoma is a pathology that affects a large part of the population, and the currently available therapies have many limitations, including the selective targeting of the site of action. This study explores the development of curcumin (CUR)-loaded nanostructured delivery systems for topical melanoma treatment, addressing CUR’s limitations in bioavailability, solubility, and stability. Methods: Binary surfactant mixtures of Vitamin E-TPGS (TPGS) and Kolliphor ELP (ELP) were selected to form stable micelles for curcumin encapsulation. A Design of Experiments (DoE) approach was applied to optimize the surfactant ratios for enhanced drug solubilization and improved cytotoxic effects on melanoma cells. The final formulation was characterized using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Nuclear Magnetic Resonance (NMR) spectroscopy to confirm its properties. Results: The final formulation, TPGS30ELP15, contained 30 mM TPGS and 15 mM ELP and led to formation of nanostructures of the expected size (hydrodinamic diameter, Dh: 13.11 ± 0.01 nm; polydispersivity index, PDI = 0.371 ± 0.05), able to solubilize 5.51 ± 1.09 mM CUR. The formulation was stable for a 120-day period stored at 4 °C and room temperature in the dark. Cytotoxicity testing in A375 melanoma cells demonstrated that curcumin-loaded micelles significantly reduced cell viability compared to free curcumin. Long-term exposure (24 h) revealed that free curcumin caused an 85% reduction in cell viability, while TPGS30ELP15 resulted in a 70% reduction. Additionally, free curcumin induced a 30% increase in cytoplasmic area, indicating necrosis, whereas TPGS30ELP15 decreased the cytoplasmic area by 20%, suggesting apoptosis. Conclusions: This study demonstrates that TPGS30ELP15 nanomicelles enhance curcumin’s anticancer effects while promoting apoptosis and minimizing necrosis, which is associated with lower inflammation and tissue damage. These findings suggest that TPGS30ELP15 offers a more favorable therapeutic profile for melanoma treatment, paving the way for safer and more effective topical therapies. Full article

This study presents an innovative approach to processing refractory zinc-bearing clinker through the synergistic application of microwave thermal treatment and ultrasonic-assisted leaching. Microwave irradiation induces phase transformations in the clinker, improving its reactivity and facilitating subsequent zinc dissolution, while ultrasonic cavitation enhances mass transfer by disrupting passivation layers. Key process parameters, including acid concentration, temperature, pulp density, and leaching time, were systematically investigated using response surface methodology (RSM) and central composite design (CCD). The results demonstrate that the optimized process conditions led to a significant increase in zinc recovery from refractory materials. Full article

Rosmarinic acid (RA) is a bioactive phenolic compound prevalent in various medicinal plants, renowned for its significant pharmacological properties. This study aims to optimise the extraction conditions of this compound from Rosmarinus officinalis L. using the response surface methodology (RSM) with a three-variable, three-level Box–Behnken design. Optimising the parameters for supercritical CO₂ (scCO₂) extraction focused on pressure (150 to 350 bar), temperature (40 to 80 °C), and co-solvent weight percentage (5 to 15% ethanol), evaluating their impact on overall yield and RA content. The optimal conditions determined were a pressure of 150 bar, a temperature of 80 °C, and 15% ethanol, yielding a total extract of 21.86 ± 1.55%, with an RA content of 3.43 ± 0.13 mg/g dry matter (DM). Scanning electron microscopy revealed that the scCO₂ treatment induced microcracks on the surface of the rosemary powder, enhancing the fluid’s ability to penetrate the plant matrix. By employing the combined scCO₂-Soxhlet method, the RA content increased to 5.78 mg/g DM. Furthermore, the final extract obtained using the Soxhlet post-scCO₂ treatment contained only trace amounts of carnosic acid (0.38 ± 0.10 mg/g DM) and carnosol (0.38 ± 0.20 mg/g DM), compared to the crude extract obtained solely with Soxhlet, which exhibited significantly higher concentrations of 8.45 ± 2.98 mg/g DM of carnosol and 16.67 ± 0.94 mg/g DM of carnosic acid. This work highlighted an innovative extraction strategy based on the coupling of scCO₂ and Soxhlet, which significantly increased RA content while reducing concentrations of other compounds such as CA and CAR. This approach makes it possible to produce RA-enriched extracts, offering considerable potential for future large-scale applications and commercialisation. Full article