Search Results (1,692)

This study presents a novel approach that integrates Discrete Event Simulation (DES) with Design of Experiments (DOE) techniques, framed within a stochastic optimization context and guided by a multi-objective goal programming methodology. The focus is on enhancing the operational efficiency of an emergency department (ED), illustrated through a real-world case study conducted in a Chilean hospital. The methodology employs Response Surface Methodology (RSM) to explore and optimize the impact of four critical resources: physicians, nurses, rooms, and radiologists. The response variable, formulated as a goal programming function, captures the aggregated patient flow time across four representative care tracks. The optimization process proceeded iteratively: early stages relied on linear approximations to identify promising improvement directions, while later phases applied a central composite design to model nonlinear interactions through a quadratic response surface. This progression revealed complex interdependencies among resources, ultimately leading to a local optimum. The proposed approach achieved a 50% reduction in the aggregated objective function and improved individual patient flow times by 7% to 26%. Compared to traditional metaheuristic methods, this simulation–optimization framework offers a computationally efficient alternative, particularly valuable when the simulation model is complex and resource-intensive. These findings underscore the value of combining simulation, RSM, and multi-objective optimization to support data-driven decision-making in complex healthcare settings. The methodology not only improves ED performance but also offers a flexible and scalable framework adaptable to other clinical environments seeking resource optimization and operational improvement. Full article

Bacterial cellulose (BC) is a pure, crystalline biopolymer with broad applications, though large-scale production remains limited by the high cost of culture media. This study evaluated the use of artichoke bract waste as an alternative substrate for BC production by Komagataeibacter rhaeticus QK23, focusing on culture optimization and physicochemical characterization of the resulting biopolymer. Infrared spectroscopy revealed functional groups characteristic of cellulose, hemicellulose, lignin, and inulin, along with structural sugars (glucose 24%, xylose 5.07%, arabinose 4.96%, galactose 8.81%, and mannose 1.75%). After hydrolysis with H₂SO₄, up to 11.81 g/L of reducing sugars were released and incorporated into Hestrin–Schramm medium lacking glucose. Using a central composite design, inoculum dose (10–20%) and incubation time (7–14 days) were optimized under static conditions at 30 °C. The highest yield (1.57 g/L) was obtained with 20% inoculum after 14 days. The product corresponded to type I cellulose with a crystallinity index of 81.87%, and AFM analysis revealed a surface roughness of 32.96 nm. The results demonstrate that artichoke hydrolysates are a viable and sustainable source for BC production, promoting agricultural waste valorization and cost reduction in industrial biotechnology. Full article

The by-products of Cavia porcellus (legs and head) were valorized for collagen extraction using ultrasound-assisted extraction (UAE). Process optimization was performed through response surface methodology (central composite design) considering amplitude, cycle, and time as factors. Samples were pretreated with NaOH and butyl alcohol, followed by acetic acid extraction under controlled sonication. The quadratic models for yield and hydroxyproline showed excellent fit (high R², R²adj, and R²pred) with no significant lack of fit. The optimal conditions were identified at 100% amplitude, cycle = 1, and 27.47 min, and these were validated experimentally, yielding 28.15 ± 0.19% collagen and 4.18 ± 0.12% hydroxyproline, values that closely matched predictions. The optimal extract exhibited a hydrodynamic diameter of 599.3 nm, a ζ-potential of −61.3 mV, and a polydispersity index of 0.33, indicating a highly stable colloidal dispersion with submicron fibrils. SEM micrographs confirmed fibrillar bundles consistent with the particle size distribution, while FTIR spectra showed characteristic amide bands indicative of triple-helix preservation. These results demonstrate that UAE of guinea pig by-products produces collagen with high structural integrity and colloidal stability, highlighting its potential for food and biomaterial applications. Full article

Francis turbines operating in sediment-laden flows experience efficiency loss and reduced service life due to abrasive wear. To enhance wear resistance, this study optimized the turbine at Mupo Hydropower Station in Sichuan Province. Using the Plackett–Burman design, three runner parameters were identified as most influential: blade number, inlet setting angle, and outlet setting angle. A central composite design based on response surface methodology was then applied to these factors. Multiple regression models linking the parameters to turbine head, efficiency, and wear rate were established, revealing a trade-off between hydraulic performance and wear resistance. Multi-objective optimization, a method that simultaneously addresses and balances multiple competing goals, was performed to minimize wear rate while maintaining the original head. The optimal parameter combination was obtained as follows: blade number Z₃ = 17, inlet setting angle ${\alpha }_1$ = 65°, and outlet setting angle ${\alpha }_2$ = 22°. Numerical results demonstrate a 32.3% reduction in runner wear under these parameters, with the head requirement satisfied, confirming a significant improvement in overall turbine performance. Full article

The ultrasound-assisted extraction (UAE) method was optimized to extract bioactive compounds from Licaria armeniaca tissues. Extraction time, solid–liquid ratio (m/v), and ethanol percentage were investigated using a central composite rotational design and response surface methodology (RSM). Antioxidant activity (DPPH) and total phenolic content (TPC) served as the response variables. Most efficient extraction conditions were obtained for leaves (64.88% ethanol, 26.07 min, 6.23% m/v; R² = 0.93) and thin branches (73.81% ethanol, 31.34 min, 11% m/v; R² = 0.74). For thick branches, no significant predictive model was obtained, and optimal points were defined based on the best observed TPC and DPPH results (50% ethanol, 35 min, 11% m/v). The optimized extracts were analyzed by liquid chromatography–tandem mass spectrometry associated with molecular networking, GNPS (Global Natural Products Social Molecular Network) library searching, and machine learning tools. Metabolomic profiling indicated that leaves contained mainly alkaloids (46.34%), amino acids and peptides (19.51%), and shikimate derivatives and phenylpropanoids (12.20%). Thin branches showed predominance of alkaloids (35.97%), amino acids and peptides (20.86%), and carbohydrates (12.23%), while thick branches contained alkaloids (46.34%), amino acids and peptides (25.00%), and fatty acids (14.26%). Additionally, the extracts displayed significant cytotoxic activity against cancer cell lines of AGP-01 (malignant gastric ascites), AHOL (Human glioblastoma) and A549 (lung cancer) with IC50 values less than 50 μg/mL. Full article

This study aimed to develop an environmentally friendly and relatively efficient method for extracting natural antioxidants from avocado by-products while investigating the antioxidant mechanisms of their core bioactive components on multiple dimensions. In vitro antioxidant assays (ABTS, FRAP, SAFR, SFR, ORAC, DPPH) demonstrated that flavonoid procyanidin was the primary antioxidant component in avocado seeds, exhibiting the strongest activity (DPPH EC₅₀ = 3.6 µg/mL). The Hill model indicated a positive synergistic effect (n = 3.1). Chemical and molecular mechanism analyses revealed that avocado seeds exert antioxidant activity predominantly through hydrogen atom transfer (HAT) and electron transfer (ET) pathways. The model predictions suggested procyanidins may stably bind to protein targets in the Keap1-Nrf2 pathway and NOX2 via hydrogen bonding, hydrophobic interactions, and π-cation interactions. Furthermore, response surface methodology (RSM) was employed to optimize the extraction process of avocado seed antioxidants in an ethanol-water system. This study underscores the considerable health benefits and antioxidant capacity of avocado by-products, supporting their promising application in functional foods formulations. Full article

The growing global demand for lithium, driven by its pivotal role in battery production, highlights the need for alternative technologies to recover this metal from low-grade and anthropogenic raw materials. This study investigates lithium extraction from aluminosilicate tailings of rare-metal production by sulfate roasting with concentrated sulfuric acid, followed by aqueous and hydrochloric acid leaching. Mineralogical analysis confirmed lithium mainly in muscovite and biotite (isomorphic substitutions) and partly as spodumene within the aluminosilicate matrix. The optimal parameters of thermochemical treatment were determined as 300 °C for 1 h at a liquid-to-solid ratio of 1:6. Subsequent aqueous leaching (90 °C, 1 h, L/S = 6:1) achieved a lithium recovery of 82.3%, while HCl proved less effective. Using response surface methodology (RSM) and a central composite design (CCD), a regression model was developed predicting up to 93.4% lithium extraction at 90 °C, a liquid-to-solid ratio of 10:1, and a leaching duration of 75 min. The calculated values showed good agreement with experimental data obtained at 90 °C, L/S = 10:1, and 30 min leaching, yielding 91.92% lithium recovery. These results confirm the efficiency of the proposed thermochemical approach and provide a scientific foundation for its further development and industrial scale-up. Full article

Battery electric vehicles (BEVs) play a key role in reducing CO₂ emissions and enabling a climate-neutral economy. However, they suffer from reduced range in cold conditions due to electric cabin heating. Electrically heated thermal energy storage (TES) systems can decouple heat generation from demand, thereby preventing a loss of range. For this purpose, a novel concept based on a directly electrically heated ceramic solid media TES is investigated, aiming to achieve high storage density while enabling both high charging and discharging powers. To assess the feasibility of the proposed TES concept in BEVs, a holistic evaluation of central aspects is conducted, including experimental characterization for material selection, experimental investigations on electrical contacting, and simulations of the electrothermal charging and thermal discharging processes under vehicle-relevant conditions. As a result of the material characterization, a promising material—a silicon carbide-based composite—was identified, which meets the electrothermal requirements under typical household charging conditions and allows reliable operation with silver-metallized electrodes. Design studies with this material show gravimetric energy densities—including thermal insulation demand—exceeding 100 Wh/kg, storage utilization of up to 90%, and fast charging within 25 min, while offering 5 kW at flexible temperature levels for cabin heating during thermal discharging. These results show that the basic prerequisites for such storage systems are met, while further development—particularly in terms of material improvements—remains necessary. Full article

Ecological restoration of the Loess Plateau plays a pivotal role in mitigating land degradation and promoting regional sustainability. In this study, landscape pattern metrics were integrated into the MaxEnt model to evaluate the influence of landscape configuration on restoration planning. Nine representative species from three vegetation strata—herbs, shrubs, and trees—were selected based on ecological suitability. A comprehensive set of variables, including environmental, anthropogenic, and landscape metrics, was constructed for modeling. Results demonstrate that incorporating landscape metrics significantly enhanced the spatial explanatory power, providing a robust supplement to traditional ecological restoration assessments. Distinct responses to landscape structure were observed among vegetation types: herb species were more sensitive to patch aggregation and connectivity, shrubs preferred regular edges and larger patch size, while tree species favored extensive, low-fragmentation core habitats. Vertical structure optimization revealed that while large areas were suitable for single vegetation layers, composite vegetation configurations were more appropriate in certain central and southern subregions. These findings underscore the importance of landscape structure in guiding restoration strategies and serve as a basis for designing ecologically coherent and spatially targeted vegetation restoration plans on the Loess Plateau. Full article

Biologically treated swine farm wastewater still contains high levels of refractory organics, humic substances and antibiotic residues, posing environmental risks and limiting opportunities for water reuse. Wastewater treatment by ozonation alone suffers from low mass transfer efficiency and selective oxidation. To overcome these limitations, a catalytic ozonation process (O₃/Fe²⁺/H₂O₂) was applied and optimized using Response Surface Methodology (RSM) based on single-factor experiments and Central Composite Design (CCD) for advanced swine farm wastewater treatment. The optimal conditions ([O₃] = 25.0 mg/L, [Fe²⁺] = 25.9 mg/L, [H₂O₂] = 41.1 mg/L) achieved a COD removal of 44.3%, which was 86.8% higher than that of ozonation alone, and increased TOC removal to 29.5%, indicating effective mineralization. Biodegradability (BOD₅/COD) of swine farm wastewater effluent increased from 0.01 to 0.34 after the catalytic ozonation treatment. Humic-like and fulvic-like substances were removed by 93.7% and 95.4%, respectively, and antibiotic degradation was significantly accelerated and enhanced. The synergistic process improved ozone utilization efficiency by 33.1% and removed 53.95% of total phosphorus through Fe³⁺-mediated coprecipitation. These findings demonstrate that with catalytic ozone decomposition and production of hydroxyl radicals, the O₃/Fe²⁺/H₂O₂ system effectively integrates enhanced ozone utilization efficiency, radical synergy, and simultaneous pollutant removal, providing a cost-effective and technically feasible strategy for advanced swine farm wastewater treatment and safe reuse. Full article

Purpose: This study aimed to evaluate the effect of different coronal restoration methods on stresses in immature central incisors with regenerative endodontic treatment and excessive loss of coronal structure. Methods: A three-dimensional (3D) Finite Element Analysis (FEA) model of a maxillary central incisor treated with a 3 mm MTA coronal plug after regenerative endodontic treatment was created. Six different models were simulated: (1) intact immature tooth (control), (2) direct composite resin build-up, (3) fibre-reinforced composite build-up, (4) hybrid ceramic endocrown, (5) LiSi ceramic endocrown, and (6) endocore and ceramic crown restoration. Analyses were performed with SolidWorks/CosmosWorks, and a 150 N load was applied at a 135° angle. Results: Maximum tensile stresses were concentrated in the cervical region (4.577 MPa). Direct composite and fibre-reinforced restorations showed high stress in root dentin (3.891 and 3.841 MPa, respectively). The endocore/ceramic crown restoration (1.578 MPa) provided the closest stress distribution to the natural tooth (1.322 MPa). Conclusions: The biomechanical performance of the restoration–tooth complex depends on both the restorative material and the restoration design. In immature teeth undergoing regenerative endodontic treatment, the most biomechanically favourable restoration option was an endocore/ceramic crown. Full article

This study investigated the effects of ultrasonic treatment of olive paste prior to malaxation on oil yield (Y), enzyme activity and virgin olive oil (VOO) quality in four Croatian olive varieties: Istarska Bjelica, Rosulja, Oblica and Levantinka. The oils were extracted using the Abencor system according to a central composite experiment design, with treatment durations of 3–17 min and power levels of 256–640 W. The parameters analyzed included Y, oxidative stability index (OSI), antioxidant capacity (AC), phenolic and α-tocopherol content, volatile compounds, fatty acid profile, and the activity of lipoxygenase, β-glucosidase, polyphenol oxidase, and peroxidase. Olive variety was the most influential factor in all variables. The response surface methodology showed that ultrasonic treatment at low-to-medium intensity improved several quality attributes. For example, Y increased by 4% in Oblica, phenolic content increased by up to 17% in Istarska Bjelica, and OSI and AC increased by 13–15% in Istarska Bjelica and Levantinka. In contrast, longer treatment and higher ultrasound power had a negative effect. No significant differences were found in other parameters examined. Overall, the application of ultrasound led to measurable, though moderate, improvements in Y and VOO quality, with results strongly dependent on olive variety and treatment conditions. These results underline the need for further optimization tailored to each variety. Full article

Edible hydrogels are the central material class in 3D food printing because they reconcile two competing needs: (i) low resistance to flow under nozzle shear and (ii) fast recovery of elastic structure after deposition to preserve geometry. This review consolidates the recent years of progress on hydrogel formulations—gelatin, alginate, pectin, carrageenan, agar, starch-based gels, gellan, and cellulose derivatives, xanthan/konjac blends, protein–polysaccharide composites, and emulsion gels alongside a critical analysis of printing technologies relevant to food: extrusion, inkjet, binder jetting, and laser-based approaches. For each material, this review connects gelation triggers and compositional variables to rheology signatures that govern printability and then maps these to process windows and post-processing routes. This review consolidates a decision-oriented workflow for edible-hydrogel printability that links formulation variables, process parameters, and geometric fidelity through standardized test constructs (single line, bridge, thin wall) and rheology-anchored gates (e.g., yield stress and recovery). Building on these elements, a “printability map/window” is formalized to position inks within actionable operating regions, enabling recipe screening and process transfer. Compared with prior reviews, the emphasis is on decisions: what to measure, how to interpret it, and how to adjust inks and post-set enablers to meet target fidelity and texture. Reporting minima and a stability checklist are identified to close the loop from design to shelf. Full article

This study reports the development and optimization of a Melissa officinalis oil-based nanoemulgel for transdermal delivery using a Design-of-Experiments (DoE) approach. A Central Composite Design (CCD) was applied to optimize Tween 80 concentration and homogenization time, resulting in a nanoemulsion with a droplet size of 127.31 nm, PDI of 17.7%, and zeta potential of −25.0 mV, indicating good colloidal stability. FTIR analysis confirmed the presence of functional groups such as O–H, C=O, and C–O–C, supporting the oil’s phytochemical richness and therapeutic potential. DSC analysis revealed enhanced thermal stability and successful encapsulation, while SEM imaging showed a uniform and spherical microstructure. The drug release followed Higuchi kinetics (R² = 0.900), indicating diffusion-driven release, with the Korsmeyer–Peppas model (n = 0.88) suggesting anomalous transport. Antibacterial studies showed inhibition of Staphylococcus aureus (MIC = 250 µg/mL) and Escherichia coli (MIC = 500 µg/mL). In vivo anti-inflammatory testing demonstrated significant edema reduction (p < 0.05) using a carrageenan-induced rat paw model. These results support the potential of Melissa nanoemulgel as a stable and effective topical therapeutic for inflammatory and microbial skin disorders. Full article

Algal biorefineries constitute an emerging platform for the sustainable production of renewable bioproducts; however, their economic viability remains constrained by the high costs associated with microalgal cultivation and biomass harvesting. This study investigated an integrated strategy combining macronutrient optimization with electrocoagulation–flocculation (ECF) harvesting for Chlorella vulgaris. A Central Composite Design (CCD) was employed to optimize concentrations of NaNO₃, KH₂PO₄, and MgSO₄ with the dual objective of maximizing biomass yield and enhancing biocompound content. Subsequently, the ECF process parameters—current density, electrolysis duration, pH, and electrolyte concentration—were optimized to improve harvesting efficiency. Under the optimal macronutrient conditions (NaNO₃: 100.00 mg/L; KH₂PO₄: 222.12 mg/L; MgSO₄: 100.84 mg/L), the model predicted a maximum biomass concentration of 0.475 g/L, along with 32.79% w/w carbohydrates and 6.79 mg/L chlorophyll-a. Optimal ECF harvesting conditions (current: 0.57 A; pH: 4.00; electrolysis time: 12.70 min; electrolyte: 1.74 g/L) achieved a biomass recovery efficiency of 89.51% w/v. These results demonstrate that coupling nutrient optimization with ECF-based harvesting offers a synergistic, scalable, and cost-effective pathway to improve the sustainability of algal biorefineries. Full article