Box-Behnken Experimental Design Research Articles

Multivariate HPLC system assessment and optimization for traditional Chinese medicine: a case study of Gastrodia elata.

The development of HPLC analytical methods for traditional Chinese medicine is intricate and time-consuming, influenced by factors such as column wear, solvent purity, and instrumental settings. A comprehensive evaluation of the HPLC system is crucial to mitigate potential variability and ensure the reliability of data. This is especially important given the complex and synergistic nature of the chemical components in traditional Chinese medicine, necessitating a multivariate measurement system analysis (MSA) to assess multiple correlated quality characteristics effectively. This study introduced a multivariate MSA method based on weighted principal components (WPC) to evaluate the HPLC system for the determination of metabolites in Gastrodia elata. By integrating multiple principal components and assigning weights according to their eigenvalues, the WPC method significantly enhanced both accuracy and robustness. It demonstrated a repeatability and reproducibility (% R&R) of 26.43% and a number of distinct categories (ndc) index of 5, confirming the system's acceptability. A full factorial experimental design was employed to identify key performance factors, leading to the recommendation to use five reference solutions for the standard curve and to triple sample preparations for improved precision and accuracy. Monte Carlo simulations confirmed the reliability of the system, showing % R&R and ndc values that follow a normal distribution, ranging from 19% to 22% and 6.07 to 7.38, respectively. Chromatographic conditions were optimized using a Box-Behnken experimental design. Subsequent validation experiments verified the method's high accuracy and reliability, with all relative standard deviation values for analytical precision, repeatability, and stability below 5%. The method also exhibited high recovery rates, exceeding 91% across three concentration levels, with RSD values under 4%. In conclusion, the application of a WPC-based multivariate MSA enabled a detailed evaluation of the HPLC system, ensuring accurate and reliable measurement of quality attributes. This method exemplified a scientifically rigorous approach for developing analytical methods in traditional Chinese medicine, enhancing both precision and reliability.

Simultaneous Estimation of Pregabalin and Duloxetine Used to Treat Nerve Pain by Stability Indicating RP-HPLC Method Using the QBD Approach

Objective: A novel stability indicating RP-HPLC method was developed and validated for the simultaneous estimation of Pregabalin and Duloxetine by using the QBD approach. Method: To determine the optimal parameters for the duloxetine and pregabalin study, we used Design Expert version 13.0 in this work. The mobile phase consisted of 0.8 ml/min of methanol: water (80:20, v/v) with o-phosphoric acid-adjusted pH 3.A 250 mm × 4.6 mm ID, 5 μm particle size Cosmosil C18 column was used. The UV-3000-M detector was used to detect at 218 nm. Results: Duloxetine's retention time was 7.153 ±0.1 min, whereas Pregabalin's was 4.481±0.1 min. The ICH parameters like linearity, accuracy, robustness, ruggedness, LOD and LOQ, and system suitability were determined. Likewise, the tailing factors were found to be 1.27 and 1.26, while the theoretical plates of duloxetine and pregabalin were found to be 8313 and 8549, respectively. The recovery study shows the results (99.37–99.84% for pregabalin and 99.03–99.74% for duloxetine), and the precision was obtained with a %RSD of less than 2%. The result of the assay was 99.92 % for pregabalin and 99.39% for duloxetine. The developed method was used for the forced degradation study. The Box-Behnken design experiment using Design Expert 13.0 was adopted for the QBD approach. Conclusion: All the values obtained for different parameters were within the acceptable range of ICH. The developed method can be routinely used for the simultaneous estimation of Pregabalin and Duloxetine by using the QBD approach.

Efficient Delivery of Gold Nanoparticles and miRNA-33a Via Cationic PEGylated Niosomal Formulation to MCF-7 Breast Cancer Cells

To overcome the challenges associated with the co-delivery of AuNPs (gold nanoparticles) and miRNA as an anti-breast cancer combination therapy, niosomal systems were developed using Span 60, cholesterol, and a cationic lipid (CTAB), and the formulations were optimized using Box-Behnken experimental design. The niosomal formulations with the smallest size were selected for further optimization of size, surface charge, entrapment efficiency, and stability. To achieve this, AuNPs and DSPE-PEG2000 (2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000)were added to the formulation. The optimized niosomal formulation could effectively encapsulate AuNPs with an entrapment efficiency of 34.49% ± 0.84 and a spherical particle size of 153.6 ± 4.62 nm. The incorporation of PEG and CTAB led to notable enhancements in the overall characteristics of the delivery system. To evaluate the effectiveness of the combination therapy, various assessments such as cytotoxicity, apoptosis, and gene expression properties were conducted. The results demonstrated that the combination delivery using the new C-PEG-Nio-AuNPs (cationic pegylated niosomal gold nanoparticles) system and miRNA had the lowest IC50, the highest apoptosis rate, and the most significant upregulation of miRNA and BAX/BCL2 expression in MCF-7 cell growth. In conclusion, this innovative co-delivery approach represents a promising breakthrough in the development of therapeutic agents for breast cancer treatment. By combining multiple therapeutic agents within a single delivery system, this method has the potential to enhance treatment efficacy, reduce side effects, and improve patient outcomes.Graphical

Application of Box-Behnken design in monoglycerides production via glycerolysis of palm oil using homogenizer reactor

The glycerolysis of triglycerides (TG) to produce monoglycerides (MG) is an important pathway for glycerol valorization. However, mass transfer resistance has significantly hindered the process efficiency because the reaction is a two-phase liquid-liquid reaction. In this study, a homogenizer was used as a high shear mixing reactor (HSM) to address such issue of mass transfer resistance, and was compared to a conventional mechanically stirred reactor (MS). The effects of the rotational speed, catalyst amount, molar ratio of Gly-to-TG, reaction temperature and reaction time on MG yield were investigated using NaOH as a homogeneous catalyst. Three reaction variables were investigated by statistical analysis using the Box-Behnken (BBK) experimental design, including Gly-to-TG molar ratio (2:1–4:1), catalyst loading (0.1–0.3 wt% TG), and reaction time (15–45 min). The results indicated that the predicted maximum MG yield of 63.4 % was achieved at a reaction time of 29 min, a Gly-to-TG molar ratio of 2.7:1, and a catalyst loading of 0.274 wt% of TG, which agreed with the experimental results. The yield efficiency of HSM was 1.27×10−4 g/J, which was 9.14-fold higher than that of MS at 1.39×10−5 g/J.

Response optimisation of TiO2-supported bimetallic NiCo catalyst for the cracking and deoxygenation of waste cooking oil into jet-fuel range hydrocarbon fuels under non-hydrogen environment

Waste cooking oil is a sustainable feedstock that can be utilised to produce biojet fuel via the hydrodeoxygenation process. However, the need for hydrogen for the hydrodeoxygenation process incurs high cost. In the present work, a type of bimetallic catalyst that can deoxygenate and selectively crack free fatty acids under hydrogen-free conditions was developed. The NiCo/TiO2 catalyst was prepared via the impregnation of varying amounts of Ni and Co salts onto TiO2. Optimisation of the production conditions was performed via response surface methodology based on the Box-Behnken experimental design to maximise the deoxygenation and biojet fuel yield. A maximum deoxygenation yield of 83.13 % with 44.5 % biojet fuel selectivity was obtained from the experiment and optimisation based on Box-Behnken design (R2 > 0.9). Incorporation of Ni and Co onto TiO2 reduced the surface area of the catalyst, but active metal dispersion significantly improved the deoxygenation performance and biojet fuel selectivity. The viscosity, flash point, freezing point and net heat of combustion value of the liquid product were within the jet fuel standard specifications. Overall, the study shows the potential of bimetallic NiCo/TiO2 catalyst in waste cooking oil deoxygenation for biojet fuel production.

Scalable Synthesis of the Key Fexuprazan Intermediate and Investigation of a Reaction Mechanism.

A three-step method for the synthesis of methyl 5-(2,4-difluorophenyl)-4-methoxy-1H-pyrrole-3-carboxylate 1, a key intermediate of fexuprazan, is reported in this paper. Using low-priced sodium p-tolylsulfinate as the starting material, compound 28 was obtained with a 96.8% yield in the first step by optimizing the experimental parameters with a Box-Behnken experimental design. Subsequently, isonitrile compound 29 was obtained by dehydration. Finally, impurities 31 and 32 in the last step of the reaction were identified and converted into target product 1 by a one-pot method, which significantly improves the utilization of atoms. Key intermediate 1 was obtained via a three-step process with a yield of 68-70% and purity that exceeded 99%. In addition, the mechanism of the cyclization reaction was proposed. This method has potential for industrial production because the raw materials are inexpensive, the procedure is simple, and a high yield is obtained.

Optimization of Pectin Extraction from Melon Peel as a New Source of Pectin and Pectin Hydrolysate with Prebiotic Potential.

Food wastes have a large number of functional ingredients that have potential for valorization. Melon peels are increasingly produced as waste in food industries in Thailand. This study aimed to optimize pectin extraction conditions from melon peel for its prebiotic potential. Optimization was conducted using a response surface methodology and Box-Behnken experimental design. An analysis of variance indicated a significant interaction between the extraction conditions on extraction yield and degree of esterification (DE). These include pH and solvent-to-sample ratio. The conditions for the extraction of pectin with low DE (LDP), medium DE (MDP) and high DE (HDP) were optimized. Pectin hydrolysate from LDP, MDP and HDP was prepared by enzymatic hydrolysis into LPEH, MPEH and HPEH, respectively. LDP, MDP, HDP, LPEH, MPEH and HPEH were compared for their efficiency in terms of the growth of three probiotic strains, namely Lactobacillus plantarum TISTR 877, Lactobacillus casei TISTR 390 and Enterococcus faecium TISTR 1027. Among the samples tested, HPEH showed the highest ability as a carbon source to promote the growth and prebiotic activity score for these three probiotic strains. This study suggests that melon peel waste from agro-industry can be a novel source for prebiotic production.

Evaluation and optimization of esterified starch and Canna edulis ker fiber films for food packaging applications

Starch-based films reinforced with Canna edulis Ker fiber were developed by a reactive extrusion process in which an esterification reaction was generated using maleic anhydride as a modifying agent and glycerin as a plasticizer. A Box-Behnken experimental design and the response surface methodology allowed modeling of the mechanical and physicochemical properties and their subsequent optimization to obtain flexible or rigid materials with different approaches in food packaging. The optimal composition for the rigid and flexible material was 10 and 2 % (w/w) lignocellulosic fibers, 30 and 30 % (w/w) glycerol, and 4 and 4 % (w/w) maleic anhydride, respectively. Glycerol and maleic anhydride were the key variables that influenced the water solubility and water absorption of the materials. The values of the rigid and flexible material properties of elastic modulus, tensile strength, elongation at break, water solubility, and water absorption were 2.58 and 1.51 GPa, 112.04 and 104.56 Mpa, 6.58 and 10.44 %, 21.63 and 21.85 %, and 139.72 and 141.06, respectively.

Upcycling of industrial pea starch by rapid spray nanoprecipitation to develop plant-derived oil encapsulated starch nanoparticles for potential agricultural applications

Starch is one of the natural encapsulant materials widely used in food, pharmaceutical and cosmetic industries. Starch with high amylose content (above 40 %, w/w) is prone to form single helices V-type allomorph with a hydrophilic outer surface and a hydrophobic inner cavity making them suitable for encapsulation of hydrophobic compounds such as essential oils, fatty acids, and vitamins. Pea starch obtained from pea protein processing industries have a high amylose content (40 %, w/w) rendering them unsuitable for direct food applications as ingredients. Therefore, in this study, an in-house spraying procedure was used to synthesize nanoparticles using pea starch, to encapsulate neem oil, a natural antimicrobial compound obtained from neem plant (Azadirachta indica) seed. The synthesis of the oil-encapsulated starch nanoparticles (OESNP) was optimized using a Box-Behnken experimental design to study the influence of the processing parameters such as the initial starch concentration, homogenization speed, duration of homogenization, sample injection rate, and quantity of antisolvent (ethanol). The optimized sample showed an 80–90 % encapsulation efficiency and particle size of <500 nm. The spherical OESNPs also demonstrated sustained release of the oil compared to free oil when dispersed in water. X-ray diffraction analysis revealed the coexistence of C-type and V-type polymorphs in the loaded and unloaded nanoparticles. It is concluded that the synthesized OESNPs with controlled release hold the potential to utilize industrial pea starch waste for the delivery of natural pesticides in agriculture.

Electrochemical Approaches for Enhanced Phosphorus Recovery from Synthetic Animal Wastewater: A Comparative Analysis of Response Surface Methodology and Artificial Neural Networks

Electrochemical recovery from animal wastewater is a novel and comprehensive strategy needed in the effort to develop sustainable technology and nutrient delivery solutions, with an emphasis on nitrogen (N) and phosphorus (P) components. This research study addresses critical global environmental sustainability challenges associated with waste by contributing to the evolving conversation on nutrient recovery by using synthetic animal wastewater (SAW) as a substrate. This approach presents a viable solution for wastewater treatment and aligns with the sustainable management of water and energy resources.This research utilized a Box-Behnken experimental design framework formulated with the aid of Minitab Statistical Software. The constructed design laid out a series of experimental runs (comprising 12 distinct conditions, each replicated twice, along with five central points) to explore the influence of three different variables (Mg:Ca molar ratio, N:P molar ratio, and temperature), each at three distinct levels, on phosphorus removal efficiency. The relationship between these three variables and the removal efficiency was then investigated using two distinct modeling methods: Artificial Neural Networks (ANN) and Response Surface Methodology (RSM). ANN, part of machine learning, involves developing a model that learns from experimental data using a network of neurons for training and validation. This allows the ANN to address complex, nonlinear relationships between variables effectively. Conversely, based on statistical analysis, RSM focused on understanding the interactions between the multiple factors, using designed experiments to build a model. Employing both methods leveraged ANN's prowess in handling nonlinearity and RSM's strength in experimental design and optimization, offering a comprehensive approach to enhance P removal efficiency from SAW. The combination of these approaches provided a deep insight into the dynamics of the process, aiding in the effective optimization of the removal response.However, at optimal conditions, the ANN model predicted a higher P removal efficiency (66%) than RSM (45%). The precision of the ANN predictions was reflected in the minimal error margins with Root Mean Squared Error (RMSE) of 2.4, suggesting the robustness of this model in predicting the optimal conditions for P removal compared to the RSM, with an RMSE of 4.7. These findings underscore the potential of employing ANN and RSM to enhance the phosphorus removal process in wastewater treatment applications and show how ANN gives better predictions than RSM. Additional details will be presented at the meeting, including experimental data, regression models, and neural networks.

Advancing Sustainable Nutrition: Enhancing Physical and Nutritional Qualities of Cookies with Apple Pomace Extrudates

Apple pomace is a by-product of the apple processing industry and can be used for various uses such as animal feed, for composting, or to extract valuable compounds such as pectin or antioxidants. In recent years, it has also gained attention as a potential food ingredient due to its fibre content and antioxidant properties. The aim of this study was to examine the effect of three parameters: the percentage of wheat flour replaced by extrudate (5%, 10%, and 15%), the percentage of apple pomace in the extrudate (15%, 30%, and 45% based on the mass of corn grits), and the particle size of the extrudate (&lt;250 µm; 250–1000 µm; 1000–2000 µm) on the properties of cookies, using the Box–Behnken experimental design. The addition of extrudates enriched with apple pomace significantly increased the total fibre and ash content of the cookies. The hydroxymethylfurfural content also increased, but not above the permitted limits (25 mg/kg). The sensory quality was strongly influenced by the particle size, especially the hardness, graininess, and appearance of the cookies. The addition of extrudate led to a darker colour of the cookies and a significant increase in the proportion of red tones, but generally had no negative influence on the acceptability of the cookies and their microbiological stability during the 6-month storage period.

Synthesis of biochar-doped MgO catalyst for highly efficient conversion of glucose into formic acid at low temperatures

Formic acid (FA) is not only a significant platform chemical but also a promising candidate for hydrogen storage. Although homogeneous catalysts are commonly employed for the conversion of carbohydrate biomass into FA, which often come with substantial costs and inadequate reusability. It is noteworthy that there has been an increasing focus on the development of heterogeneous catalysts in this area, which aim to address these limitations and offer advantages such as easier separation and better reusability. Herein, an eco-friendly and efficient method for the catalytic conversion of glucose to FA by utilizing a biochar-MgO (BC-MgO) catalyst, which is prepared through pyrolysis of coconut husk biochar impregnated with magnesium chloride (MgCl2), is proposed. The FA yield at 74.6% is attained from glucose at 60 °C within only 3 h, utilizing a mere 0.1 g of catalyst and hydrogen peroxide (H2O2) amount of 100%. In conjunction with random forest (RF) algorithms and box-behnken experimental designs, further optimization resulted in an increased yield of 79.1%, with a selectivity of 82.7%, in only 3.8 h at 67 °C, employing 0.1 g of catalyst amount and 125% H2O2 amounts. Notably, the BC-MgO catalyst retains its catalytic efficiency over multiple cycles, only requiring a simple straightforward regeneration procedure. The mechanism underlying the glucose conversion to FA reaction system is demystified via kinetic modeling, time-gradient studies, and model compounds experiments. Life cycle assessment (LCA) indicates that when used for glucose conversion to FA, BC-MgO catalysts generate lower CO2 emissions than traditional homogeneous catalysts such as LiOH. Concurrently, an operation cost analysis indicates that operation cost of FA production from glucose is 4.1 $/kg with the BC-MgO catalyst, which is lower than LiOH catalyst (7.5 $/kg), evidencing the dual advantage of economic viability and an improved environmental impact inherent to this novel process.

Development and Optimization of Nasal Composition of a Neuroprotective Agent for Use in Neonatology after Prenatal Hypoxia.

The intranasal route of drug administration is characterized by high bioavailability and is considered promising for rapid delivery of drugs with systemic action to the central nervous system (CNS), bypassing the blood-brain barrier. This is particularly important for the use of neuroprotective drugs in the treatment of brain tissue damage in infants caused by the effects of intrauterine hypoxia. The creation of new dosage forms for neonatology using mathematical technologies and special software in pharmaceutical development allows for the creation of cerebroprotective drugs with controlled pharmaco-technological properties, thus reducing time and resources for necessary research. We developed a new nasal gel formulation with Angiolin using a Box-Behnken experiment design for the therapy of prenatal CNS damage. It was found that the consistency characteristics of the nasal gel were significantly influenced by the gelling agent and mucoadhesive component-sodium salt of carboxymethylcellulose. We optimized the composition of nasal gel formulation with Angiolin using the formed models and relationships between the factors. The optimized nasal gel composition demonstrated satisfactory thixotropic properties. The 1% gel for neuroprotection with Angiolin, developed for intranasal administration, meets all safety requirements for this group of drug forms, showing low toxicity and no local irritant or allergic effects.

Investigation of capacitive deionization process parameters on salt adsorption capacity via experimental design approach

Process parameters of Capacitive Deionization (CDI) was investigated and optimized in this study. The effect of adsorption period (7–13 min), flow rate (5–20 ml min−1), and NaCl concentration (2–22 mM) on salt adsorption capacity was examined via Box-Behnken experimental design approach. A quadratic regression model (R2 = 0.9987) was developed, revealing significant individual and binary effects between process parameters and salt adsorption capacity. The ANOVA results demonstrated its high significance with the p-value<0.0001. Optimal conditions varied with salt concentration, indicating significant interactions between the parameters. Maximum salt adsorption capacity occurred at 5 ml min−1 flow rate and 13 min adsorption period for 22 mM NaCl, whereas for 12 mM and 2 mM NaCl concentrations, maximum adsorption capacity was obtained at the flow rate of 20 ml min−1 and duration of 13 min. This study provided deep insights into CDI modelling and optimization, crucial for water treatment advancements.

Preparation of deep eutectic solvent modified magnetic graphene oxide/metal organic framework nanocomposites for the extraction of three estrogens in cosmetics.

Anovel magnetic dispersive solid phase extraction (MDSPE) procedure based on the deep eutectic solvent (DES) modified magnetic graphene oxide/metal organic frameworks nanocomposites (MGO@ZIF-8@DES) was established and used for the efficient enrichment of estradiol, estrone, and diethylstilbestrol in cosmetics (toner, lotion, and cream) for the first time. Then, thethree estrogens were separated and determined by UHPLC-UV analysis method. In order to study the features and morphology of the synthesized adsorbents, various techniques such as FT-IR, SEM, and VSM measurements were executed. The MGO@ZIF-8@DES nanocomposites combine the advantages of high adsorption capacity, adequate stability in aqueous solution, and convenient separation from the sample solution. To achieve high extraction recoveries, the Box-Behnken design and single factor experiment were applied in the experimental design. Under the optimum conditions, the method detection limits for three estrogens were 20-30ngg-1. This approach showed a good correlation coefficient (r more than 0.9998) and reasonable linearity in the range 70-10000ngg-1. The relative standard deviations for intra-day and inter-day were beneath 7.5% and 8.9%, respectively. The developed MDSPE-UHPLC-UV method was successfully used to determine three estrogens in cosmetics, and acceptable recoveries in the intervals of 83.5-95.9% were obtained. Finally, three estrogens were not detected in some cosmetic samples. In addition, the Complex GAPI tool was used to evaluate the greenness of the developed pretreatment method. The developed MDSPE-UHPLC-UV method is sensitive, accurate, rapid, and eco-friendly, which provides a promising strategy for determining hormones in different complex samples.

A Novel Lactose/MCC/L-HPC Triple-Based Co-Processed Excipients with Improved Tableting Performance Designed for Metoclopramide Orally Disintegrating Tablets.

New co-processed excipients comprising lactose (filler and sweetener), microcrystalline cellulose (MCC, filler), and low-substituted hydroxypropyl cellulose (L-HPC, disintegrant and binder) were developed via solvent evaporation for the preparation of metoclopramide orally disintegrating tablets (MCP ODTs). Single-factor and Box-Behnken experimental designs were employed to optimize the formulation. The optimized formulation ratios were water: MCC: lactose (g/g) = 17.26:2.79:4.54:1. The results demonstrated that particles formed by solvent evaporation had superior flowability and compressibility compared to the physical mixture. Tablets compressed with these co-processed excipients exhibited a significantly reduced disintegration time of less than 25 s and achieved complete dissolution within 5 min. Pharmacokinetic studies revealed that MCP ODTs significantly improved Cmax, which was 1.60-fold higher compared to conventional tablets. In summary, the lactose/L-HPC/MCC triple-based co-processed excipients developed in this study are promising and could be successfully utilized in orally disintegrating and fast-release tablets.

MAF process for aluminum 6060: An analytical temperature modelling and chemo-mechanical analysis

The magnetic abrasive finishing process is a sophisticated micro-finishing process that enhances the surface quality of superalloys, ceramics, and composites. Surface temperature plays a pivotal role in facilitating chemo-mechanical reactions between the processed surface and abrasive particles. In triggering the chemo-mechanical response of the micro-finished surface of Aluminum 6060 (Al-6060), an analytical thermal model derived using Jaeger moving heat formulation to find the flash temperature (FT) and flash time duration (FTD) at the micro-finishing interface of the processed workpiece and the abrasive particles of the magnetic abrasive brush. Furthermore, the present work performed an RSM-based Box Behnken design experiment to analyse and explain the crucial role of machining gap, abrasive weight, Voltage, and rotational speed on surface temperature, machining surface, and hardness. ANOVA highlighted key factors in machining responses. Surface roughness and temperature were notably influenced by voltage (58.42 % and 57.62 %, respectively), while surface hardness primarily depended on abrasive weight (60.65 %). Using the developed model, extreme FT of 880 °C and 810 °C were calculated under specific conditions, along with corresponding FTD required for quasi-steady-state conditions. FT and FTD were identified as sufficient for initiating chemo-mechanical action in the MAF micro-finishing process, depending on contact pressure, the number of abrasive particles, and sliding velocity, which in turn are influenced by magnetic intensity, abrasive ratio, and rotational speed. Furthermore, a detailed examination of the finished surface was carried out using the SEM, EDS and XRD of Al-6060 which shows that the SiC does participate on the finishing surface. Chemical substrates such as Kaolinite (Al2O9Si2), Iron silicide (FeSi), and Cristobalite (O2Si) had formed on the finished surface of Al-6060 due to the chemo-mechanical action between the SiC and workpiece material.

Yield optimization of chemically synthesized p-TSA-doped polyaniline using a Box-Behnken design of experiment

Yield optimization of chemically synthesized p-TSA-doped polyaniline using a Box-Behnken design of experiment

Simulation and verification of discrete element parameter calibration of pulverized coal particles

ABSTRACT To enhance the simulation efficiency of the EDEM discrete element numerical simulation software for coal powder mineral particles, experimental data on the rest angle of coal powder particles were collected as the response variable. Five parameters related to coal powder particles within the Hertz-Mindlin no-slip contact model were selected for investigation. Initially, the Plackett-Burman experiment identified three parameters: collision restitution coefficient, static friction coefficient, and rolling friction coefficient, significantly influencing the resting angle. Subsequently, the steepest ascent experiment determined the significant parameter ranges as follows: the collision restitution coefficient ranged from 0.20 to 0.40, the particle-particle static friction coefficient ranged from 0.30 to 0.50, and the particle-particle dynamic friction coefficient ranged from 0.06 to 0.10. Finally, the second-order regression model for the angle of repose and the saliency parameters was developed and optimized using the Box-Behnken experimental design. The following parameter combination was obtained: the collision recovery coefficient was 0.30, the particle-particle static friction coefficient was 0.49, and the particle-particle dynamic friction coefficient was 0.09. This study aimed to compare the angle of repose between the simulation experiment and the actual experiment. The relative error was only 1.02%, indicating that the simulation experiment achieved the optimal parameter combination.

Optimising miniaturised hydrocyclones for enhanced separation of microplastics

Microplastics, particularly those in the 5–20µm range, pose substantial risks in aquatic environments, yet effective removal techniques are limited. This study assesses two critical geometric parameters of a 10 mm mini-hydrocyclone: inlet radius and insertion angle. Along with the inlet velocity, they are optimised collectively to enhance the MPs’ removal. Computational Fluid Dynamics (CFD) simulations using the Mixture model and Reynolds stress model were employed to track the particle–water–air interactions, revealing the flow dynamics and absence of an air core. The Response Surface Methodology (RSM) using a Box-Behnken design of experiments was adopted to assess the impact of the geometric and operational parameters and determine the optimal design. Recovery efficiency, concentration efficiency, and split rate were recorded during experiments and compared with CFD results, showing a good agreement between experiments and CFD simulations. The resulting novel design achieved an 88.53% MPs recovery and a concentration efficiency of 1.83, which represents an obvious improvement over the commercial design’s MPs recovery efficiency of 79.97% and concentration efficiency of 1.68. Simulations reveal that the novel design shortens the path for MPs through the forced turbulence region and modifies the velocity and turbulence fields, enhancing the concentration gradient of MPs within the mini-hydrocyclone’s chamber. Moreover, the novel design exhibits a more robust response to inlet velocity variations, a crucial advantage for its application in arrays. Experiments further confirm that a matrix composed of 10 novel mini-hydrocyclones achieves 10 percentage points higher recovery efficiency than the matrix with 10 commercial mini-hydrocyclones. These findings mark a significant step towards effective MP removal, addressing a critical environmental issue.