Response Surface Analysis Research Articles

Effect of Vibration Conditions on the Seed Suction Performance of an Air-Suction Precision Seeder for Small Seeds

The air-suction precision seeder for small seeds is a planting machine, characterized by precision, high efficiency, and ease of operation, that uses air suction technology to sow small grain seeds at set intervals and depths into the soil. However, the forced vibration, enhanced by the increase in the operating speed, affects the seeding accuracy of the seeder and limits the seeding efficiency. To study the influence of vibration conditions on the seed suction performance of the air-suction precision seeder, we developed a computational fluid dynamics–discrete element coupling method to construct a bidirectional fluid–solid coupling numerical simulation model of the seed suction process under vibration conditions. Within the range of operating speeds from 0.6 km/h to 8 km/h, we quantitatively studied the population movement under different vibration frequencies, vibration amplitudes, negative pressure values, and seeding disc speeds and verified the simulation model and its analysis results through bench tests. The numerical results show that the interaction between the vibration frequency, vibration amplitude, and negative pressure value has the most significant impact on the single-seed rate. In addition, via variance analysis and response surface analysis, the optimal range of negative pressure values for achieving high single-seed rates under different vibration frequencies (4~10 Hz), vibration amplitudes (3~7.5 mm), and seeding disc speeds (4~50 rpm) was determined. The results indicate that, rather than the higher the negative pressure value, the higher the seed suction rate, the optimal negative pressure value for achieving a high seed suction rate varies with the specific vibration frequencies and amplitudes.

A Comprehensive Review on Implementation of Quality by Design in Varied Pharmaceutical Formulations

This review article investigates how Quality by Design (QbD) ideas are used in different pharmaceutical development processes, such as the creation of analytical methods, formulation optimization, and nanoparticle production. In order to improve product quality, reliability, and regulatory compliance, it covers a variety of studies that use QbD approaches. Critical quality attributes and process variables are discovered and optimized to meet desired product characteristics through systematic methodologies such as central composite design, factorial design, and response surface analysis. The experiments demonstrate the adaptability and effectiveness of the QbD strategy in pharmaceutical development by examining a range of drug delivery systems, including lipid nanoparticles and fast dissolving tablets. The significance of QbD is emphasized in the article as a means of guaranteeing uniform product quality, fulfilling regulatory obligations, and enhancing patient outcomes.

Prediction and comparative analysis of friction material properties using a GA-SVM optimization model

PurposeWith the rapid advancement in the automotive industry, the friction coefficient (FC), wear rate (WR) and weight loss (WL) have emerged as crucial parameters to measure the performance of automotive braking systems, so the FC, WR and WL of friction material are predicted and analyzed in this work, with an aim of achieving accurate prediction of friction material properties.Design/methodology/approachGenetic algorithm support vector machine (GA-SVM) model is obtained by applying GA to optimize the SVM in this work, thus establishing a prediction model for friction material properties and achieving the predictive and comparative analysis of friction material properties. The process parameters are analyzed by using response surface methodology (RSM) and GA-RSM to determine them for optimal friction performance.FindingsThe results indicate that the GA-SVM prediction model has the smallest error for FC, WR and WL, showing that it owns excellent prediction accuracy. The predicted values obtained by response surface analysis are closed to those of GA-SVM model, providing further evidence of the validity and the rationality of the established prediction model.Originality/valueThe relevant results can serve as a valuable theoretical foundation for the preparation of friction material in engineering practice.

The Optimization of the Steam-Heat-Treated Process of Rattan (Calamus simplicifolius) Based on the Response Surface Analysis and Its Chemical Changes

The objective of this study is to investigate the impacts of steam heat treatment parameters (e.g., temperature, time, and pressure) on the impact toughness of rattan (Calamus simplicifolius). The Box–Behnken design response surface analysis was employed to optimize the steam heat treatment parameters. Impact toughness was selected as the evaluation index, with single-factor tests conducted as a baseline for comparison. Changes in chemical composition, cellulose crystallinity, and pyrolysis properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, Thermogravimetry–Fourier transform infrared (TG-FTIR) spectra, and wet-chemistry methods for both untreated control samples and the heat-treated samples. The results show that a 1 h steam heat treatment at 160 °C under 0.1 MPa pressure has the optimal process parameters for the rattan. The achieved impact toughness value closely matches the predicted value at 71.29 kJ/m2. After the steam heat treatment, hemicellulose and cellulose contents decrease, whereas relative lignin content increases significantly, leading to improved toughness characteristics in Calamus simplicifolius samples. The TG results indicate that maximum weight loss occurs at temperatures of 352 °C, 354 °C, and 361 °C, respectively, for three different samples. This suggests that the thermal stability is enhanced as a result of the heat treatment. These findings will help optimize the heat treatments of the rattan material.

Preparation of Multi‐Grain Flour with High Content of Resistant Starch and the Mechanism Underlying the Improved Digestion Resistance

AbstractTo acquire the optimum treatment strategy that leads to the highest yield of resistant starch (RS) in multigrain flour (MF), wheat flour, whole oat flour, and whole buckwheat flour are used to prepare antidigestive MF by using pullulanase debranching combining heat–moisture treatment (P‐HMT). Based on the single factor tests and response surface analysis, the optimum conditions for the treatment of MF are determined as follows: pullulanase 62.6 U g−1, autoclaving 21.3 min, HMT at 100 °C, and 30.4% water content for 6.0 h. Under these conditions, the yield of RS in the flour reaches 77.42%. P‐HMT causes protein denaturation, starch gelatinization, and flour clumps in MF, facilitating starch recrystallization and interactions among short‐chain starch, monomeric proteins, and lipids. All these findings are further confirmed by the conversion of starch crystal from A‐type to B+V‐type, the improvement of starch short‐range molecular order, and the presence of more binary/ternary complexes in treated flour. In brief, the starch digestion resistance improvement in the treated flour is attributed to the recrystallization of short‐chain starch and interactions between starch and protein/lipid.

Optimizing Nanosuspension Drug Release and Wound Healing Using a Design of Experiments Approach: Improving the Drug Delivery Potential of NDH-4338 for Treating Chemical Burns.

NDH-4338 is a highly lipophilic prodrug comprising indomethacin and an acetylcholinesterase inhibitor. A design of experiments approach was used to synthesize, characterize, and evaluate the wound healing efficacy of optimized NDH-4338 nanosuspensions against nitrogen mustard-induced skin injury. Nanosuspensions were prepared by sonoprecipitation in the presence of a Vitamin E TPGS aqueous stabilizer solution. Critical processing parameters and material attributes were optimized to reduce particle size and determine the effect on dissolution rate and burn healing efficacy. The antisolvent/solvent ratio (A/S), dose concentration (DC), and drug/stabilizer ratio (D/S) were the critical sonoprecipitation factors that control particle size. These factors were subjected to a Box-Behnken design and response surface analysis, and model quality was assessed. Maximize desirability and simulation experiment optimization approaches were used to determine nanosuspension parameters with the smallest size and the lowest defect rate within the 10-50 nm specification limits. Optimized and unoptimized nanosuspensions were prepared and characterized. An established depilatory double-disc mouse model was used to evaluate the healing of nitrogen mustard-induced dermal injuries. Optimized nanosuspensions (A/S = 6.2, DC = 2% w/v, D/S = 2.8) achieved a particle size of 31.46 nm with a narrow size range (PDI = 0.110) and a reduced defect rate (42.2 to 6.1%). The optimized nanosuspensions were stable and re-dispersible, and they showed a ~45% increase in cumulative drug release and significant edema reduction in mice. Optimized NDH-4338 nanosuspensions were smaller with more uniform sizes that led to improved physical stability, faster dissolution, and enhanced burn healing efficacy compared to unoptimized nanosuspensions.

Optimization of synthesis parameters of PUF/ENB microcapsules for self‐healing applications using factorial design methodology

AbstractThis study introduces a systematic experimental approach aimed at enhancing the production process of poly(urea‐formaldehyde) (PUF) microcapsules filled with 5‐ethylidene‐2‐norbonene (ENB) using in situ emulsion polymerization. Essential parameters were identified through a prior Plackett Burman (PB) design, leading to the implementation of a 24‐1 fractional factorial design. The key parameters selected encompassed stirring speed, poly(ethylene‐alt‐maleic anhydride) (EMA) emulsifier content, pH of the reaction, and the quantity of 1‐octanol. Optimal conditions for polymeric microcapsule synthesis were determined using a statistical analysis of the complete factorial design, facilitating the development of representative mathematical models for the process. A comprehensive evaluation of response variables including microcapsule diameter, yield, encapsulated content, stability, and thermal degradation was conducted. Utilizing response surface analysis (RSM), it was determined that the PUF/ENB(2C) condition (stirring at 700 rpm, a reaction pH of 3.0, and EMA content of 0.425 g) resides within the optimized synthesis region, producing microcapsules exhibiting favorable morphological characteristics, yield of 52% and encapsulated content of 80%.

Optimization of process parameters of manna bar, a kind of nougat, production

Manna bar, a kind of nougat, is a typical Iraqi-Iranian confectionary that is made by manna, glucose syrup, table sugar, egg white, cardamom and nuts (pistachio, walnuts, or almond). Manna bar is a similar confectionary with French nougat, Italian torrone, and Spanish turrón, but produced from different raw materials and different process. The aim of this research was to determine influence of cooking temperature, cooking time and mixing time on the quality of manna bars during the production. The analyses made in this study were moisture content, pH value, color and textural properties. It was found that increasing cooking temperature from 100°C to 120°C, cooking time from 5 min. to 15 min., and mixing time from 10 min to 30 min. decreased moisture content from 15.58 to 8.50 %, but increased (p<0.05) hardness from 131.56 to 856.16 g. Browning index and pH value decreased (p<0.05) by increasing mixing time. Response surface analysis was carried out to optimize the production of manna bar. It’s results showed that cooking at 120°C for 10.10 min and mixing of 21.26 min was the best condition as desirability = 0.682. This study showed that high temperature at 120°C and long cooking for 15 min., and mixing for 30 min. improved the physical and chemical properties of manna bars.

Influence of coal cowl parameters on the coal loading process of thin coal seam shearer drum

The low loading rate of the thin coal seam shearer drum is a severe obstacle to the efficient mining of thin seam resources, and the auxiliary drum loading through the cowl is an effective measure to alleviate this situation. However, the working mechanism of the coal cowl still remains unclear. In this paper, with the help of the discrete element method and the modeling experiment method, the effects of coal cowl’s offset distance, tilt angle and wrap angle on the coal loading rate under different loading modes of the drum are investigated; and the significance of various factors and their interactions to the drum coal loading rate is explored by designing response surface experiments. The findings show that a monotonous negative correlation between the offset distance of the coal cowl and the coal loading rate is identified, and that a smaller offset distance can effectively improve the coal loading rate of the drum. The conveying torque is significantly increased, easily inducing the drum choking, coal recycling coal over-crushing. Along with the increasing tilt angle, the rate of ejection loading decreases monotonically, and the rate of pushing loading increases first and then decreases. Coal loading rate is weakly affected by changes in coal cowl’s wrap angle. The results of response surface analysis reveal that the most significant factors affecting the drum’s coal loading rate are tilt angle and offset distance in ejection and pushing loading modes, respectively. The conclusions drawn here offer implications for improving the coal loading performance of the thin coal seam shearer drum, as well as certain guidance on the optimal design of coal cowl parameters.

Population dynamics of Variola albimarginata Baissac, 1953 and Variola louti Fabricius, 1775 (Perciformes: Serranidae) in Sulawesi Sea, Indonesia

Abstract. Achmad DS, Nurdin MS, Tilome AA, Moore AM. 2024. Population dynamics of Variola albimarginata Baissac, 1953 and Variola louti Fabricius, 1775 (Perciformes: Serranidae) in Sulawesi Sea, Indonesia. Biodiversitas 25: 978-989. The lyretail groupers Variola louti Fabricius, 1775 and Variola albimarginata Baissac, 1953 (Epinephelinae) are valuable foodfishes. IUCN Red List assessments classified both species as Least Concern, while noting that some stocks are overfished. The purpose of this study on the population dynamics of Variola groupers in Kwandang Bay was to evaluate the exploitation level for both species in this important grouper fishing area of the Sulawesi Sea, Indonesia. Population dynamics parameters were calculated based on length-frequency data collected from October 2022 to September 2023 using the ELEFAN I response surface analysis option in FISAT II. The asymptotic length at infinity TL? was 54.90 cm for V. louti and 54.40 cm for V. albimarginata with von Bertalanffy growth function K values 0.54 and 0.55, respectively. Recruitment occurred throughout the year, with monthly percentages of 1.08-13.52 % and 1.61-14.99%, respectively. Natural and fishing mortality were M = 1.04/year-1 and F = 1.17/year-1 for V. louti and M = 1.05/year-1 and F= 2.56/year-1 for V. albimarginata giving F/M ratios of 1.13:1 and 2.44:1. Beverton and Holt yield per recruit analysis gave exploitation rates (E = 0.53/year-1 and E = 0.71/year-1) exceeding the maximum sustainable value Emax = 0.37/year-1, indicating overexploitation of both species. To achieve the optimum exploitation rate of E50 = 0.24, fishing effort needs to be reduced by 29% for V. louti and 47% for V. albimarginata. Management options include setting a minimum legal size with recommended values of 32-33 cm and temporary closures during the peak reproductive season in May-June.

Parent-adolescent discrepancies in educational expectations, relationship quality, and study engagement: a multi-informant study using response surface analysis.

Whether parental educational expectations for adolescents serve as a source of motivation or stress depends on the extent to which adolescents hold expectations for themselves. Previous research on the discrepancies between parental and adolescent educational expectations and their impact on learning engagement has been limited by traditional statistical tests, and lacking an examination of the internal mediating mechanism of parent-child relational quality from both parental and adolescent perspectives. This cross-sectional study, utilizing a multi-informant design, examined the association between discrepancies in parents' and adolescents' reports of expectations, and adolescents' study engagement, as well as the mediating role of parent-child relational qualities perceived by both parties. The sample for this study consisted of 455 adolescents and their parents from 10 classes in a junior high school in Wuhan, Hubei Province, China. The adolescents had an average age of 12.8 years, and 51.6% of them were boys. Both parents and adolescents reported on their expectations and perceived relational quality, while adolescents also filled out questionnaires assessing their learning engagement. Data were analyzed using polynomial regressions with response surface analysis. The results revealed that when adolescents reported high expectations, regardless of whether their parents reported high or low expectations, adolescents reported satisfied relationships and high learning engagement. In contrast, parents reported satisfied relationships when both parties reported high expectations, or when parents reported higher expectations than adolescents. Lastly, the association between discrepancies in expectations and learning engagement was significantly mediated by adolescent-reported relationships but not parent-reported ones. These findings highlight the importance of considering multiple perspectives when studying the association between expectations and adolescent study engagement. This research advances our comprehension of the dynamics between parent-adolescent educational expectation discrepancies and adolescent learning engagement, offering insights for more nuanced and effective parenting strategies tailored to foster optimal educational outcomes.

Impact of supply–demand matching on citizen satisfaction: analysis based on expectancy disconfirmation model

In the context of ensuring the well-being of citizens, the energy industry should predominantly adhere to the people-oriented approach. Investigation of citizen satisfaction through the lenses of power supply and societal demand is of utmost importance. This study constructs a satisfaction model based on expectancy disconfirmation theory, employs response surface analysis to explore the impact of matching degree between demand and supply on citizen satisfaction. The results show that citizen satisfaction is notably higher in case of a match between public expectations and supply quality compared to mismatch scenarios. Furthermore, instances involving both high public expectations and high supply quality, yield greater satisfaction compared to scenarios involving low public expectations and low supply quality. Importantly, citizen satisfaction experiences a dip when public expectations surpass supply quality, unlike situations where public expectations fall short of supply quality. Policy awareness does not moderate the effect of matching analysis on citizen satisfaction. This research enriches the scope of understanding the complex nature of public satisfaction, offering theoretical support for the high-quality development of power supply departments, catering to both energy needs and well-being of citizens. Thus, the current study significantly contributes to promoting the sustainable and high-quality development of the local social economy.

Profile of the Effectiveness Factor under Optimal Operating Conditions for the Conversion of Ortho-Xylene to Phthalic Anhydride in a Fixed-Bed Tubular Reactor

The objective of this research is to find the effectiveness factor of the catalyst particles for the most favorable conditions of the phthalic anhydride production in a fixed bed reactor, with the aim of achieving the highest rate of phthalic anhydride production compared to other secondary products and analyzing the areas of lower effectiveness for the modification of the reactor design. Initially, the material and the energy balances in the catalytic bed are solved to obtain the concentration and temperature profiles based on the radius and length of the reactor, using polymath software(Polymath® v6.2 Software Minitab 19 Matlab 2019) with the data from literature. Once the profiles reproducibility was verified using the initial data (inlet temperature, pressure in the reactor, reactor wall temperature, reactor radius and mass flow rate) the experimental design 35 carry out, which generates 243 “experiments”, whose response variable (phthalic anhydride concentration) was obtained using Matlab. Subsequently, the variables were analyzed using the Minitab 18® that, through the response surface analysis method, allowed us to obtain the optimal values of the tested variables. Then, Subsequently, material and energy balances coupled with Fourier and Fick’s laws, along with the effectiveness factor equation, were applied, resulting in the generation of 9 coupled differential equations. Upon implementing the finite difference method, this yielded 90 nonlinear algebraic equations, which were solved using the Polymath software. A total of 78 particles were preselected based on their radial and axial positions to determine the effectiveness factor profile, with values ranging from 0.83 to near unity. The lower values correspond to the points with higher temperature, as evidenced by the calculations performed.

Design of experiments and white analytical chemistry-driven green and sensitive spectrofluorimetric estimation of pregabalin in its pharmaceutical dosage forms and spiked human plasma

BackgroundPregabalin (PGB) is a medication with anticonvulsant, analgesic and anxiolytic properties, employed in the treatment of epilepsy, neuropathic pain, fibromyalgia, restless leg syndrome, opioid withdrawal syndrome and generalized anxiety disorder. Several spectrofluorimetric techniques have been documented for the determination of PGB in pharmaceutical dosage forms. However, these published methods typically involve the use of expensive and toxic organic solvents and reagents, as well as high reaction temperatures for PGB analysis. These components pose risks to aquatic life and the environment, making them less environmentally friendly and user-friendly. A recent advancement in analytical chemistry has introduced a white analytical approach, providing an economical, eco-friendly and user-friendly method for the development of analytical procedures.ObjectivesTherefore, a green and sensitive spectrofluorimetric determination of PGB, guided by white analytical chemistry principles, has been conducted utilizing distilled water as an environmentally friendly solvent.MethodsThe establishment of the spectrofluorimetric method involved employing the design of experiments approach to ensure a robust, precise and accurate estimation of PGB. Response surface analysis and optimization of critical procedural variables and responses were carried out using the central composite design. The validation of the developed method adhered to the guidelines outlined in ICH (International Council for Harmonization) Q2 (R1) and M10.ResultsThe established spectrofluorimetric method was utilized to determine the PGB content in commercially available formulations and human plasma samples spiked with PGB. The obtained results were in accordance with the labeled claim of PGB in the formulations. The recovery of PGB in the spiked human plasma samples ranged from 85 to 90% of the spiked amount.ConclusionsThe greenness profiles of the published and suggested spectrofluorimetric methods for PGB estimation were evaluated and compared using the AGREE calculator, GAPI software and ESA tool. The suggested method demonstrated sensitivity, robustness, environmental friendliness and user-friendliness.

Peracetic acid activated by nickel cobaltite as effective oxidizing agent for BPA and its analogues degradation

The presented research concerns the use of nickel cobaltite nanoparticles (NiCo2O4 NPs) for the heterogeneous activation of peracetic acid and application of NiCo2O4-PAA system for degradation 10 organic micropollutants from the group of bisphenols. The bisphenols removal (initial concentration 1 μM) process was optimized by selecting the appropriate process conditions. The optimal amount of catalyst (115 mg/L), peracetic acid (PAA) concentration (7 mM) and pH (7) were determined using response surface analysis in the Design of Experiment. Then, NiCo2O4 NPs were used to check the possibility of reuse in subsequent oxidation cycles. The work also attempts to explain the mechanism of oxidation of the studied micropollutants. The participation of the sorption process on the catalyst was excluded and based on the experiments with radical scavengers it can be concluded that the oxidation proceeds in a radical pathway, mainly with participation of O2•- radicals. Experiments conducted in real water matrices exhibit low impact on degradation efficiency. Toxicity tests with green alga Acutodesmus obliquus and aquatic plant Lemna minor showed that post-reaction mixture influenced growth and the content of photosynthetic pigments in concentration dependent manner.

Ultrasound-Assisted Multi-Enzyme Extraction for Highly Efficient Extraction of Polysaccharides from Ulva lactuca.

Ulva polysaccharides present several physiological activities including antiviral, antitumor and anti-plasmodial effects. However, current processing usually results in low yields and high prices, thus lacking commercialization potential. The aim of this study was to develop an efficient method for the extraction of Ulva polysaccharides with high biological activity. The effect of cell wall-degrading enzymes including cellulase, hemicellulase, pectinase and protease on Ulva polysaccharide extraction was studied by statistical mixing design. Using the most effective enzyme preparations as the basic components, the optimal proportions of the enzyme mixture were determined as follows: cellulase 35.3%, pectinase 34.5%, alkaline protease 30.2%, which increased the polysaccharide yield from 6.43% in the absence of enzymes to 26.68%. Subsequently, through response surface analysis, the optimal conditions were determined: enzyme concentration of 1.5%, enzymatic time of 1.1 h, ultrasonic time of 90 min and enzymatic temperature of 60 °C. Under the optimal extraction conditions, the extraction yield of Ulva polysaccharides could be increased to 30.14%. Moreover, extracted polysaccharides exhibit strong antioxidant properties in DPPH, ABTS, hydroxyl radical, superoxide radical and H2O2-induced cellular damage models. This study laid a solid foundation for the use and development of Ulva polysaccharides.

Evaluation of Bruising Susceptibility and Response of Pears under Impact Loading through Finite Element Analysis

Mechanical damage and bruising of fruit is a critical problem in the food industry. Minimizing brusing and damage can be achieved by designing energy-absorbing structures and packaging systems in order to ensure the long-term quality of fresh produce. The aim of this study is to investigate the response and bruise susceptibility of pears under impact loading conditions through finite element analysis (FEA) methods. In this paper, three impact heights (0.25 m, 0.5 m, and 1.0 m), four impact material surfaces (poplar wood, rubber, cardboard, and acrylonitrile butadiene styrene (ABS) plastic), two packaging sizes (standard 0.22″ and sandwich lattice 2.1″), and three impact design structures (rigid, corrugated, and honeycomb) are considered. Based on mesh sensitivity analysis, a mesh element of 1.5 mm was adopted for all simulations, assuring the accuracy of results and considering the trade-off between mesh size and computational time. The response surface analysis approach was utilized in order to develop predictive empirical models related to pear bruising. Results revealed that the rubber-based impact platform yielded minimal bruise susceptibility at all heights, while standard-sized corrugated cardboard performed best at a height of 0.25 m. Furthermore, single, double, and triple layers of packaging cardboard were tested. We observed that adding a second soft layer of corrugated cardboard reduced the stress on the pear by around 33%. However, adding a third layer only reduced stress by 5%. The 3D-printed honeycomb ABS has potential as protective packaging but would require further investigations and parameter optimization. Stacking multiple layers of cardboard on top of each other is a cost-effective solution that could improve damping and, therefore, ensure good quality and increase the shelf life of the fresh produce. This study will help decision-makers select the optimal energy-absorbing material for cushioning and packaging designs in order to improve the handling and post-harvesting logistics of fresh produce.

Degradation of pyrene by Xanthobacteraceae bacterium strain S3 isolated from the rhizosphere sediment of Vallisneria natans: active conditions, metabolite identification, and proposed pathways.

Polycyclic aromatic hydrocarbons (PAHs) were typical environmental contaminants that accumulated continuously in sediment. Microbial degradation is the main way of PAH degradation in the natural environment. Therefore, expanding the available pool of microbial resources and investigating the molecular degrading mechanisms of PAHs are critical to the efficient control of PAH-polluted sites. Here, a strain (identified as Xanthobacteraceae bacterium) with the ability to degrade pyrene was screened from the rhizosphere sediment of Vallisneria natans. Response surface analysis showed that the strain could degrade pyrene at pH 5-7, NaCl addition 0-1.5%, and temperature 25-40°C, and the maximum pyrene degradation (~ 95.4%) was obtained under the optimum conditions (pH 7.0, temperature 28.5°C, and NaCl-free addition) after 72h. Also, it was observed that the effect of temperature on the degradation ratio was the most significant. Furthermore, eighteen metabolites were identified by mass spectrometry, among which (2Z)-2-hydroxy-3-(4-oxo-4H-phenalen-3-yl) prop-2-enoic acid, 7-(carboxymethyl)-8-formyl-1-naphthyl acetic acid, phthalic acid, naphthalene-1,2-diol, and phenol were the main metabolites. And the degradation pathway of pyrene was proposed, suggesting that pyrene undergoes initial ortho-cleavage under the catalysis of metapyrocatechase to form (2Z)-2-hydroxy-3-(4-oxo-4H-phenalen-3-yl) prop-2-enoic acid. Subsequently, this intermediate was progressively oxidized and degraded to phthalic acid or phenol, which could enter the tricarboxylic acid cycle. Furthermore, the pyrene biodegradation by the strain followed the first-order kinetic model and the degradation rate changed from fast to slow, with the rate remaining mostly slow in the later stages. The slow biodegradation rate was probably caused by a significant amount of phenol accumulation in the initial stage of degradation, which resulted in a decrease in bacterial activity or death.

Parent–child educational aspiration congruence and adolescents' internalizing problems: The moderating effect of SES

Previous studies have found that adolescents and their parents may hold discrepant views about educational aspirations. However, little is known about how these discrepancies affect adolescents' internalizing problems and the moderating effect of SES on the relation between (in)congruence of parent–child educational aspirations and adolescents' internalizing problems. Therefore, this study explored the relation between (in)congruence of parent–child educational aspirations and adolescents' internalizing problems, and further tested the moderating role of SES. Based on two-wave survey data collected from a nationally representative sample of 8194 parent–child dyads in China (51.3 % boys, mean age = 13.58 years), multilevel polynomial regression and response surface analysis were performed to investigate the hypotheses. The results found that (1) internalizing problems were minimal when the two educational aspiration variables were congruent, (2) internalizing problems were the highest when the discrepancy between child educational and parental educational aspirations was largest, and (3) SES moderated the relation between (in)congruence in educational aspirations and adolescents' internalizing problems. The study's results not only comprehensively and intuitively reveal the influence of parents' and children's educational aspirations on adolescents' internalizing problems, but also provide targeted guidance and suggestions regarding parenting practices for families from diverse SES backgrounds.

Optimization of alkaline hydrothermal treatment for humic acids production from corn straw digestate using the response surface methodology

Anaerobic digestion (AD) technology was widely used for treating waste biomass, during which a large amount of lignin-rich digestate would be produced, needing further treatment. In this study, corn straw digestate (CSD) was used as raw material for hydrothermal humic acids (HHA) producing through alkaline hydrothermal treatment (AHT). According to the response surface analysis, the optimal reaction conditions were determined to be 156°C, 2 hours, and 5% KOH (% of the dry digestate), resulting in a HHA yield of 40.3 wt%. Structural characterization analysis showed the produced HHA had abundant oxygen-containing functional groups (e.g., C-O and CO) in HHA and aromatic structures, which also showed good thermal stability. By AHT with hemicellulose and lignin, the HHA yields reached 79.2%. Hemicellulose and lignin proved to be important components for HHA formation. In addition, the protein content in the EPS extraction solution of HC was significantly reduced compared to CSD, indicating that the dewaterability of the digestate were improved after AHT. This technique provides a feasible approach for the further utilization of residual lignocellulosic materials after anaerobic digestion.