Search Results (2,559)

Uneven seed spacing, skewed stalk posture, and inconsistent planting depth remain major challenges in horizontal sugarcane planting. To address these issues, a semi-automatic transverse sugarcane planter integrating a supply–buffer–discharge seeder and multiple soil-engaging components was developed. The seed placement process and the interaction between stalk discharge and soil disturbance were investigated through Discrete Element Method (DEM) simulations and experiments. First, the working principle and key component parameters of the whole machine were determined. It integrated the processes of soil crushing, furrowing, seeding, ridge covering. In addition, a dynamic analysis was conducted on the inter-particle disengagement effect during the two-step seed filling process of lifting and discharging. Secondly, a discrete element simulation model for the entire process of soil-engaging seed arrangement operations was established for the machine. The effects of forward speed and seed outlet position were studied using a discrete element method (DEM) simulation model that coupled soil disturbance flow with stalk-seed discharge behaviour. Furthermore, a response surface methodology (RSM) experiment was performed on the seeding test bench to quantify the effects of guiding parameters on seed placement uniformity. The determination coefficient (R²) of the established regression model exceeded 0.9, indicating high prediction accuracy. The optimal collaborative parameter combination was optimized as follows: forward speed of 1.2 m·s⁻¹, buffer inclination angle of 55°and supply roller speed of 26 r·min⁻¹. After verification, the seed placement uniformity coefficient of the seeder reached 91.8 ± 1.4%, which met the expected accuracy requirements for horizontal planting. Full article

Medlar (Mespilus germanica L.) fruit presents a good source of bioactive compounds. This study aimed to optimize the traditional extraction method, maceration, in order to obtain extracts rich in polyphenols. The total phenolic compounds (TPC) from physiologically ripe (PRMFs) and consumable ripe (CRMFs) medlar fruits were extracted to develop models with high accuracy and prediction capacity by response surface methodology (RSM). Furthermore, the main phenolic compounds in the extracts were quantified using HPLC, and the extracts were tested for antioxidant activity and hypoglycemic activity. The extracts were prepared according to a central composite design. The extraction parameters for both PRMFs and CRMFs were time (30–210 min), ethanol concentration (20–80%) and solid-to-solvent ratio (1:10–1:50). The obtained results indicated that the optimal conditions for the extraction were 210 min, 66.55% ethanol, and 1:50 solid-to-solvent ratio (PRMF), and 120 min, 74.96% ethanol, and 1:50 solid-to-solvent ratio (CRMF). Under the optimized conditions, values for TPC were in agreement with the values predicted by RSM. Isoquercitrin, rutin, procyanidin B2, chlorogenic acid and caffeic acid were the most abundant compounds in both PRMF and CRMF optimized extracts. TPC, antioxidant activity, and inhibition of α-glucosidase and α-amylase enzymes did not show significant differences (p > 0.05) among PRMF and CRMF extracts. Full article

This study presents an integrated approach for producing antioxidant-rich polar fractions from Inula salicina L. via pressurised ethanol/water extraction (PLE-EtOH/H₂O), optimised by coupling a central composite design and response surface methodology (CCD-RSM) with Aspen Plus^® simulation. The effects of PLE temperature, extraction time, and EtOH/H₂O ratio for yield, total phenolic (TPC) and flavonoid (TFC) content, and Trolox equivalent antioxidant capacity (TEAC) measured in ABTS^•+-scavenging, cupric ion reducing antioxidant (CUPRAC) and oxygen radical absorbance (ORAC) assays were assessed via a multi-response optimisation approach. Optimal conditions were set at 82 °C, 27 min, and 60% EtOH (v/v), yielding ~29 g extract per 100 g plant material, characterised by high TPC (227 mg GAE/g), TFC (34 mg QE/g), and TEAC values in the CUPRAC (1473 mg TE/g), ABTS (869 mg TE/g), and ORAC assays (1165 mg TE/g). The TPC and TEAC values of the post-extraction residue were >92% lower than those of unextracted I. salicina, confirming efficient recovery of the major portion of antioxidant-active constituents by PLE-EtOH/H₂O. The high in vitro radical scavenging capacity, reducing power, and photoprotective potential (sun protection factor ~50 at 0.5 mg/mL) of the I. salicina extract are consistent with its phenolic-rich composition, with chlorogenic acid (~97 mg/g extract) and its derivatives being the major constituents. The validated Aspen Plus^® model closely aligned with the CCD-RSM predictions, supporting process scale-up and energy feasibility and demonstrating an industry-relevant, green-solvent PLE process for producing higher value-added I. salicina fractions with potential applications in the food, pharmaceutical, nutraceutical, and cosmetic sectors. Full article

This study systematically investigates the influence of steel fibers on the mechanical properties of cement concrete. End-hook, shear, and milling type steel fibers were selected, with comparisons made to copper-plated and corroded steel fibers. The effects of fiber type, aspect ratio (40–60), and volume content (0.5–1.5%) on the compressive, flexural, and splitting tensile properties of concrete were analyzed. A multi-objective mechanical performance prediction model was established using a combined macro- and micro-scale testing approach, integrated with response surface methodology (RSM) and I-optimal design. The results indicate that steel fibers can significantly enhance the overall mechanical properties of concrete. Among the types tested, the end-hook fiber exhibited the best performance in compressive and splitting tensile strength, and the 28-day compressive strength increased by 41% compared with plain concrete, while the milling fiber showed the greatest improvement in flexural strength, and the value reached up to 72%. Furthermore, the failure mode observations indicated that steel fiber incorporation fundamentally altered the fracture behavior of concrete, transitioning it from brittle fracture to quasi-ductile behavior with post-crack load-carrying capacity, particularly for end-hook and milling fiber types. An optimal parameter window for the fiber reinforcement effect was identified, with the best comprehensive performance achieved at an aspect ratio of 50–60 and a fiber content of 0.5–1.0%. The enhancement effect of copper-plated and corroded steel fibers was limited due to reduced interfacial bonding performance. The developed model demonstrates high prediction accuracy, providing a theoretical and experimental basis for the engineering application of fiber-reinforced concrete. Full article

The use of nanoparticles (NPs) synthesized from plant extracts is an alternative to conventional pesticides for the control of agricultural pests. This study aimed to optimize the conditions of synthesis of silver–zinc nanoparticles (Ag-ZnNPs) using extracts of Ocimum basilicum L. and Crotalaria longirostrata Hook. & Arn. and to evaluate their phytotoxic impact on maize seedlings. The Ag-ZnNPs (Ag-Zn nanoparticles) were synthesized by redox reaction between metal ions and reducing metabolites present in the extracts. A response surface methodology (RSM) with three factors (extract concentration, heating time and pressure) was applied to determine the optimal synthesis conditions. The phytotoxicity of nanoparticles (NPs) on maize seedlings was subsequently evaluated on root growth, oxidative stress enzymes (CAT, POD, and APX), and physiology of seedlings. Nanoparticles synthesized from C. longirostrata extract demonstrated superior properties, with an optimization of synthesis (R² = 95.3%) where the extract concentration (1:4 v/v; p < 0.01) was the critical factor influencing the reduction of metallic ions to nanoparticles. These NPs exhibited superior stability, smaller size (<100 nm), and zeta potential greater than 30 mV compared with O. basilicum extracts. Their NPs exhibited poorer optimization of synthesis (R² = 43.8%) without the effect of any of the variables evaluated. Essentially, C. longirostrata NPs showed no phytotoxic effects on maize seedlings’ physiological parameters and enhanced root growth (117.2 mm) without negatively affecting photosynthesis (PSII 70-81 FvFm). Ag-ZnNPs synthesized with C. longirostrata exhibited optimal stability and size, along with no observed possible phytotoxicity effects, unlike O. basilicum NPs, which cause stress on maize seedlings. Therefore, Crotalaria longirostrata NPs could represent a promising material for agricultural pest control, with no apparent adverse effect on maize crops. Full article

This study investigated the extraction and characterization of pectin from the peel and the pulp of Opuntia ficus-indica (OFI) cladodes, aiming to define sustainable and optimized extraction conditions and to evaluate the applicability of the extracted pectin in film development for food packaging. Cladodes were chemically characterized, confirming their richness in sugars, dietary fiber, and bioactive compounds. Different solvents (citric acid, acetic acid, and acidified water) and pH values (1.5–7) were evaluated, with citric acid (1% w/v) selected as the most suitable solvent due to its extraction efficiency and food-grade nature. Process optimization was performed using response surface methodology (RSM), considering liquid-to-solid ratio (5–15 v/w), extraction time (40–60 min), and temperature (70–90 °C). The regression models showed good fit, with R² values of 88.79% for peel and 89.20% for pulp. Extraction yield was mainly influenced by liquid-to-solid ratio, time, and temperature, with optimal conditions defined as 10 v/w, 40 min, and 80 °C. Pectin obtained under optimized conditions was characterized by Fourier-transform infrared (FTIR) spectroscopy, showing functional groups consistent with commercial citrus pectin, while galacturonic acid content and degree of esterification confirmed its purity and classification as low-methoxyl pectin, supporting its suitability for further film production. Additionally, the extracted pectin was successfully incorporated into blended films with commercial pectin, resulting in films with improved water resistance and water vapor barrier performance. Overall, OFI cladodes represent a promising and sustainable source of pectin for biodegradable food packaging applications. Full article

This study employed a metakaolin-based geopolymer (GP) to solidify potassium copper hexacyanoferrate after its saturation with adsorbed Cs⁺. The experiment was designed using response surface methodology (RSM) in the Design–Expert 13 software, targeting the compressive strength and cumulative leaching fraction of the solidified form. A regression model was developed to achieve the multi-objective optimization of the comprehensive performance of the GP solidified product. Regression analysis identified the optimal mix proportion as Na₂O/Al₂O₃ = 0.84, SiO₂/Al₂O₃ = 2.8, and H₂O/Na₂O = 10.23. Under these conditions, the experimentally measured compressive strength was 23.41 MPa. The 42-day cumulative leaching fractions at 25 °C and 40 °C were 7.906 × 10⁻⁴ cm and 1.5923 × 10⁻³ cm, respectively, both significantly below the national standard threshold (Standard Code GB7023-2011) of 2.6 × 10⁻¹ cm. The percentage error remained within 10%, indicating strong agreement with predicted values. These results suggest that metakaolin-based GP exhibits promising potential for the immobilization of radionuclides. Full article

The lignin in chestnut rose waste restricts composting efficiency. This study aimed to optimize lignin degradation in feedstock pretreatment using response surface methodology (RSM) and evaluate the effects on composting efficiency and greenhouse gas emissions. A Box–Behnken design with three factors (temperature, time and biochar) was used to determine optimal conditions. The RSM-optimized pretreatment was then compared against biochar pretreatment, high-temperature pretreatment without biochar, and no pretreatment to evaluate their effects on composting efficiency. The results showed that the RSM-supported optimal pretreatment (79.2 °C, 5.2 h, 10.3% biochar, R² = 0.9970, p < 0.0001) degraded 59.31% of lignin in chestnut rose waste. The optimized pretreatment condition increased the lignin degradation rate by 31.5% during composting compared to a lack of pretreatment. The quality of the compost was significantly improved, with the total N and NO₃⁻ contents increasing by 22.0% and 65.2%, respectively. Furthermore, the optimized pretreatment reduced cumulative CH₄ and N₂O emissions by 37.5% and 36.5%, respectively. These findings suggest that RSM-optimized pretreatment effectively enhances composting efficiency and mitigates the environmental impacts of chestnut rose waste composting. However, this study was limited to laboratory-scale conditions, and further field-scale validation is needed. Full article

With the rapid evolution of urbanization and artificial intelligence technology in China, small, intelligent road sweepers have emerged as a highly promising technical solution to address urban cleaning challenges. The development and breakthrough of high-performance dust collection trays (DCT) stand as the core prerequisite for the large-scale practical application of such sweepers. Although blowing–suction integration technology theoretically offers substantial potential for improving dust removal efficiency, it has not received adequate attention in the sweeper field, particularly in the research on its application in unmanned, small-sized models. In this study, a fresh concept of an efficient DCT was proposed, and its numerical method was verified by experiment. Then, the design work for this efficient DCT was efficiently carried out by combining computational fluid dynamics (CFD) numerical simulation with response surface methodology (RSM). Finally, the influence mechanisms of three key operational parameters of nozzle airflow velocity, suction negative pressure, and vehicle travel speed on the dust removal effect were numerically investigated. The results indicated that the parameter combination of DCT with an 18° blowing angle, 20° shoulder angle, and 0.2 diameter-to-length ratio was recommended, and its dust removal efficiency could reach a peak level of 98.7% when the nozzle blowing velocity, negative pressure at suction port, and travel speed were respectively 14 m/s, −1800 Pa, and 1.4 m/s. This research provides important theoretical support and a feasible technical pathway for the design of high-performance DCTs. Full article

The surface quality of machined gears is closely related to operational energy efficiency and service durability, which affect the achievement of dual carbon goals in sustainable manufacturing. This study proposes a radial pre-stressed grinding method for gear manufacturing. Firstly, an analytical model for the radial pre-stress exerted on the gear inner hole was established by virtue of thick-walled cylinder theory. Secondly, a simulation and experiment were conducted under the same pre-stress conditions to obtain the radial stress. The theoretical, simulated, and experimental results were compared and discussed. Then, gear grinding simulations were performed at different pre-stress levels, grinding depths and grinding speeds. Finally, the grinding parameters were optimized by means of response surface methodology (RSM). This study recommends incorporating gears manufactured with radial pre-stressing into relevant industrial standards for green and low-carbon development. The results indicate that applying radial pre-stress to the gear inner hole significantly influences surface roughness and residual compressive stress after grinding, whereas it exhibits a minimal effect on grinding force. After optimization, compared with the initial simulation results, surface roughness is reduced by 12.5%, the absolute value of residual compressive stress is increased by 52.6%, and grinding force is decreased by 2.1%. The implementation of radial pre-stressed grinding in gear manufacturing requires institutional support, including its integration into green standard institutions, the development of technical specifications, and the establishment of promotion mechanisms. Such integration can be facilitated through national ‘Green Factory’ initiatives, comprehensive intellectual property protection, and targeted personnel training. Full article

This study aimed to comparatively optimize and evaluate the quality characteristics of Washington Navel orange slices using vacuum microwave drying (VMD) and conventional hot air drying (HAD) systems. Response Surface Methodology based on the Box–Behnken design was applied to both systems. For the models developed in the VMD system, the coefficient of determination (R²) was found to be in the range of 0.96–0.97, and the optimum conditions were determined as 4 kW power, 60 °C temperature, and 2 mm slice thickness. For HAD, the optimum conditions were determined as 78 °C temperature, 1.57 m/s air velocity, of 2.3 mm slice thickness. VMD showed superior performance compared to hot air drying in terms of total phenolic preservation, retention of bioactive compounds, and rehydration capacity. Hydroxymethylfurfural (HMF) formation was higher during hot-air drying. The effective moisture diffusivity (D_eff) was significantly higher in VMD (8.38 × 10⁻¹⁰ m²/s) than in HAD (1.49 × 10⁻¹⁰ m²/s), indicating enhanced internal moisture transport under vacuum microwave conditions. The results revealed that VMD is an efficient technology for producing high-quality dried citrus products with improved bioactive retention and reduced processing time. Full article

This study involves the design of an integrated machine dedicated to the core processes of classifying, shelling, and cleaning to address the critical drawbacks of existing Camellia oleifera fruit processing equipment, including the high manual labor requirement, low operating efficiency, unsatisfactory shelling and cleaning performance, and severe camellia seed damage. The classifying system employed a slat drum structure, and response surface methodology (RSM) was utilized to determine and optimize its operating parameters: spiral blade speed: 20 rpm; drum speed: 10 rpm; and rise angle: 9.6°. The shelling system employed a horizontal flexible structure, and polyurethane was the core material. We determined through single-factor experiments that the shelling drum rotation speed was 200 rpm. For the cleaning system, a composite mode integrating drum screening and friction separation was adopted, and single-factor experiments further determined the optimal operating parameters: cleaning drum rotation speed: 20 rpm; friction conveyor shaft rotation speed: 150 rpm; and cleaning inclination angle: 25°. The performance test verified that the integrated machine achieved outstanding results: the shelling rate reached 97.52%, the camellia seed breakage rate did not exceed 2.42%, the impurity content rate did not exceed 1.99%, the loss rate was less than 3.66%, and the processing capacity reached 2614 kg/h. Full article

This study employed UPLC-MS/MS to determine the contents of major polyphenolic compounds and proanthocyanidins (PCs) in Kyoho grape seeds, optimized the extraction method and conditions for PCs using response surface methodology (RSM), and further evaluated the scavenging activities of PCs against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (•OH) radicals as well as their effects on growth, immunity, and oxidative stress in mice. Three hundred and sixty 3-week-old male mice (42.28 ± 0.31 g) were assigned to a single factor complete randomized trial design and fed with six different diets including 0 mg/kg vitamin E(VE) + 0 mg/kg PCs, 100 mg/kg VE, 25 mg/kg PCs + 75 mg/kg VE, 50 mg/kg PCs + 50 mg/kg VE, 75 mg/kg PCs + 25 mg/kg VE and 100 mg/kg PCs, respectively. The results demonstrated that PCs were identified as the predominant phenolic compounds, accounting for 29.6% of total phenolic substances in Kyoho grape seeds. Additionally, the ultrasound-assisted extraction method was superior to the shaker-assisted and low-temperature infiltration extraction methods, with optimal conditions of 60% ethanol concentration, material-to-liquid ratio of 1:20 g/mL, temperature of 30 °C, and extraction time of 50 min. Scanning electron microscopy (SEM) revealed that ultrasound treatment effectively disrupted the seed surface structure, facilitating PC release. In vitro, PCs exhibited significantly stronger DPPH and hydroxyl radical (•OH) scavenging activities than vitamin C (VC), Trolox, and gallic acid. Compared with the control group, mice fed diets containing PCs and VE showed higher superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-PX) activity, and total antioxidant capacity (TAOC), Catalase (CAT), GPX and inflammation factor 10 (IL-10) genes levels in the serum and liver (p < 0.05), whereas the levels of immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), as well as the mRNA expression of IL-1β and TNF-α, showed the opposite trend (p < 0.05). In conclusion, the antioxidant capacity of PCs was stronger than that of VC and VE. The addition of PCs improved the antioxidant activity and immune function of mice. Full article

Plum pomace (PP), a key by-product of plum juice processing, is a rich yet underutilized source of dietary fiber. However, its high-value exploitation is severely limited by the lack of efficient extraction and modification technologies. This study optimized the extraction of soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) from plum pomace (PP) via Design of Experiments (DOE), and evaluated their modification effects. Alkaline extraction was screened as the optimal method for IDF, and orthogonal experiments determined the optimal conditions: solid-to-liquid ratio 1:20 g/mL, 14 g/L NaOH, 60 °C, and 80 min, achieving a high extraction yield of 62.18%. For SDF, enzymatic extraction was superior, and response surface methodology (RSM) optimized the process to a solid-to-liquid ratio of 1:15.5, 1.0% enzyme dosage, 61.5 °C, and 92 min, with a yield of 29.3%. Physical, chemical, and biological modifications all significantly enhanced SDF’s water/oil-holding capacity, cholesterol/glucose adsorption capacity, and cation exchange capacity. Biologically modified SDF showed the most significant enhancement, with WHC of 5.58 ± 0.05 g/g, OHC of 4.38 g/g, CAC of 7.68 mg/g, and CEC of 3.28 mmol/g. These results provide technical support for the high-value utilization of PP and lay a foundation for its application in functional foods and nutraceuticals. Full article

Polycyclic aromatic hydrocarbons (PAHs)-contaminated soils are often concomitantly polluted with heavy metals, which form combined contamination through cation–π interactions and other mechanisms. However, the mechanism by which bacteria degrade PAHs under combined pollution conditions remains insufficiently studied. In this study, a benzo[a]pyrene (BaP)-degrading bacterial strain, Rhodococcus sp. PDS1, was isolated from the co-contaminated soil of an abandoned coking plant in a steel factory. This strain can not only detoxify arsenic via reductive transformation, but also mediate extracellular arsenic oxidation and efficiently degrade BaP, a high-molecular-weight (HMW) polycyclic aromatic hydrocarbon with low bioavailability and high toxicity. Response surface methodology (RSM) experiments were conducted to optimize the degrading conditions of strain PDS1, considering four factors: pH, temperature, BaP concentration, and trivalent arsenic As(III) concentration. The results showed that the BaP removal by PDS1 would reach 93.59% under the RSM-obtained optimal conditions: pH 7.7, BaP concentration 8.96 mg/L, As(III) concentration 0.82 mM, and culture temperature 36.0 °C. The transcriptome of the strain under the combined stress of arsenic and BaP was further analyzed. The results indicated that the introduction of arsenic induced the upregulated expression of different genes in the arsenic detoxification ars operon and the pcaH/G gene (encoding protocatechuate 3,4-dioxygenase, a key enzyme in BaP degradation) to varying degrees. These findings clarify the mechanism of the degradation of HMW-PAHs such as BaP by strain PDS1 under PAHs–arsenic combined pollution, lay a solid theoretical foundation for subsequent practical applications, and demonstrate the broad prospects of strain PDS1 in the remediation of actual complex contaminated soils. Full article