Search Results (1,924)

In greenhouses, high humidity, low light, and inadequate ventilation conditions, along with continuous and high-density planting, promote the proliferation of soilborne pathogens. Among these pathogens, Fusarium oxysporum Schltdl (F. oxysporum) is a notably challenging one, causing root rot of tomato plants in greenhouse cultivation. To address this issue, this study applied a pulsed electric field (PEF) to target the elimination of F. oxysporum in suspension and soil media. Initially, PEF parameters were systematically explored in suspensions to determine the effective ranges for the elimination of F. oxysporum. The results revealed that the effective ranges for achieving the desired microbial reduction were an electric field strength (EFS) between 5–15 kV·cm⁻¹, a pulse number within the range of 100–500, and a pulse width of 10–20 µs. Subsequently, the impact of soil moisture content, soil bulk density, and soil type on soil dielectric breakdown field strength was analyzed within the range from previous results. Based on these findings, the soil experiments were conducted with parameters designed to prevent dielectric breakdown. Specifically, for sampling soil with a moisture content of 16.2% and a bulk density of 1.31 g·cm⁻³, the maximum effective application of electric field strength was 9.5 kV·cm⁻¹, accompanied by 1000 pulses and a pulse width of 20 µs. Finally, building on these results, soil samples were sterilized within a parameter range that spanned an electric field strength of 5–9.5 kV·cm⁻¹, a pulse number between 100–500, and a pulse width of 10–20 µs. Response surface methodology (RSM) analysis further identified the optimal parameter combination: an electric field strength of 8.2 kV·cm⁻¹, 306 pulses, and a pulse width of 15 µs, resulting in an average lethal rate of 76.16% for F. oxysporum sterilization in soil. These findings suggest the potential use of PEF against F. oxysporum and other pathogens in greenhouse soils, and provide theoretical foundations for further experiments, thereby contributing to the sustainable advancement of greenhouse agriculture. Full article

We conducted a mechanistic and experimental study on zinc fluoride roasting for the recovery of NdFeB waste to address the difficulties faced during this pyrometallurgical recovery process, such as the high dependence on the quality of raw materials, the high energy consumption involved in roasting transformations, and the low added value of mixed rare earth products. Thermodynamic calculations showed the feasibility of fluorinating rare earths in NdFeB waste, and one-factor experiments were performed. The results showed that at a roasting temperature of 850 °C, a reaction time of 90 min, and 100% ZnF₂ addition, the fluorination rate of rare earths could reach 95.69%. In addition, after analyzing the mesophase composition of a clinker under different roasting temperature conditions, it was found that, when the roasting temperature exceeded 850 °C, the fluorination rate of rare earths was reduced, which was consistent with the thermodynamic results. On this basis, response surface methodology (RSM) was used to carry out experiments to investigate in depth the effects of various factors and their interactions on the fluorination rate of rare earths, which provides a sufficient experimental basis for the recovery of NdFeB waste via fluorination roasting. The results of this study show that ZnF₂ addition had the greatest influence on the rare earth fluorination reaction, followed by roasting temperature and roasting time. According to the optimization results of the model, the optimal roasting conditions were determined as follows: 119% ZnF₂ addition at 828 °C, a roasting time of 91 min, and a rare earth element fluorination rate of 97.29%. The purity of the mixed fluorinated rare earths was as high as 98.92% after leaching the roasted clinker with 9 M hydrochloric acid at a leaching temperature of 80 °C, a liquid–solid ratio of 4 mL/g, and a leaching time of 2.5 h. This study will lay the foundation for promoting the application of pyrometallurgical technology in the recycling of NdFeB waste. Full article

Nanoparticles (NPs) have attractive properties that have received impressive consideration in the last few decades. Polylactic acid nanoparticles (PLA-NPs) stand out as a biodegradable polyester with excellent biocompatibility. This investigation introduces PLA-NPs prepared by using the emulsification-solvent volatilization (O/W) method. The effects of ultrasonication time, organic-to-aqueous phase volume ratio, surfactant Tween-20, and PLA on particle size as well as the polydispersity index (PDI) were investigated using a one-factor combination with Response Surface Methodology (RSM). The result indicates that, on the one hand, PLA was the key factor affecting particle size, which gradually increased as the amount of PLA increased from 0.01 to 0.1 g. The particle size of NPs gradually decreased as the surfactant Tween-20 increased from 0.25 mL to 1 mL in the aqueous phase. The volume ratio of the organic phase to the aqueous phase increased from 1:10 to 1:1, with the particle size initially decreasing (from 1:10 to 1:5) and subsequently increasing (from 1:5 to 1:1). As the ultrasonication time increased from 20 min to 40 min, the particle size initially increased (from 25 to 30 min) and then decreased (from 30 to 40 min). On the other hand, Tween-20 was the main factor of PDI, and with the increase of Tween-20, PDI changed significantly and increased rapidly. The volume ratio of the organic phase to the aqueous phase increased from 1:10 to 1:1, resulting in the stabilization and subsequent gradual decrease of the PDI. With the increase of ultrasonication time (20–40 min), PDI tended to be stable after the increase. The effect of PLA on PDI was not significant, and the change of PLA concentration did not cause a significant change in the size of PDI. Full article

The objective of this study was to determine the seed flow characteristics and in-row seed distribution uniformity under different operating conditions to develop mathematical models and to optimize the seed distribution uniformity in the seeding of sage seeds by a micro-granule applicator equipped with a conveyor belt seed-metering unit. In this study, weighing tests were used to determine the seed flow characteristics, while sticky belt tests were used to determine the in-row seed distribution uniformity. While the evaluations of flow uniformity were carried out depending on the coefficient of variation values (CVs), in-row seed distribution uniformity evaluations were carried out using the values of the variation factor (V_f) and goodness criterion (λ). Central Composite Design (CCD) was used as the experimental design. Based on the analysis of data obtained from the experiments, the polynomial functions were developed for V_f and λ values and the models were optimized. The forward speed was determined as 2.14 m s⁻¹, the seed rate was 13.9 kg ha⁻¹, and the seed falling angle was 42.73° for the V_f model, while these values were determined as 2.43 m s⁻¹, 14.7 kg ha⁻¹, and 33.11°, respectively, for the λ model. All these findings reveal that the metering unit equipped with conveyor belt could be used for the seeding of sage seeds successfully. Data and information found in this work would have great potential to be used as a guide for farmers, manufacturers, and scientists who work in such areas. Full article

Date seeds, often discarded during industrial processing, are an underexploited by-product rich in polyphenols with significant antioxidant potential. This study explores the extraction of polyphenols from date seeds using microwave-assisted extraction (MAE) with an organic solvent. The extraction process was optimized using response surface methodology (RSM), focusing on extraction time, ethanol concentration, and temperature. The optimal extraction conditions were 46% (v/v) of ethanol, at 62 °C and for 27.3 min. Under these optimized conditions, the extraction yield and total phenolic content of the extract are 12.5% and 59 mg gallic acid equivalent g⁻¹ of date seed, respectively, as confirmed by the experimental tests. The extract’s antioxidant activity was confirmed through DPPH, ABTS, and FRAP assays. High-performance liquid chromatography with diode–array detection (HPLC–DAD) identified major phenolic compounds, including procyanidin B1, catechin, quercetin-3,5′-di-O-glucoside, epicatechin, procyanidin B, and syringic acid, alongside eight other tentatively identified compounds. These findings underscore the potential of MAE as an environmentally friendly technique for producing polyphenol-rich extracts from date seeds, adding value to this by-product and opening avenues for its application in food and nutritional products. Full article

Vacuum impregnation (VI) of natural extracts is often used as a pretreatment for fruit dehydration. Apple slices were subjected to VI [X_VP: vacuum pressure (−0.4 to −0.2 mbar), X_IT: impregnation time (2–10 min), and X_RT: restoration time (1–3 min)] of Hibiscus sabdariffa (HS) calyces aqueous extract and optimized using response surface methodology (RSM). Total soluble phenols (TSP) and flavonoids, antioxidant capacity, and physicochemical parameters were evaluated before and after vacuum impregnation. Also, optimized VI apple slices were heat air-dried and characterized for all the mentioned parameters. Under the experimental conditions, all vacuum-impregnated apple slices increased in TSP content, with impregnation time, restoration time, and the interaction between impregnation time and vacuum pressure being the key factors. According to RSM, the optimal VI conditions for TSP (R² = 0.99) were X_VP −0.4 bar, X_IT: 6.73 min, and X_RT 3 min. VI also improved flavonoid and antioxidant activities (DPPH and ABTS) of apple slices and promoted changes in total soluble solids, pH, titratable acidity, water activity, moisture, and color (luminosity, a*, and b*) parameters. Additionally, vacuum-impregnated apple slices (under optimized conditions) were further dehydrated, resulting in an increase in soluble phenols, flavonoids, and antioxidant activity. VI with HS extract is an effective alternative for developing dehydrated apple slices with an increase in antioxidant compounds. Full article

The carbonization method for preparing Nano ZnO is characterized by its simplicity, ease of reaction control, high product purity, environmental friendliness, and potential for CO₂ recycling. However, traditional carbonization processes suffer from poor heat and mass transfer, leading to in situ growth and agglomeration, resulting in low carbonization efficiency, small specific surface area, and inferior product performance. To enhance micro-mixing and mass transfer efficiency, ZnO derived from zinc ash calcination was used as the raw material, and hydrodynamic cavitation technology was employed to intensify the carbonization reaction process. The reaction mechanism of hydrodynamic cavitation was analyzed, and a single-factor experimental study investigated the effects of reaction time, reaction temperature, solid–liquid ratio, calcination temperature, incident angle, cavitation number, and position height on the specific surface area and carbonization rate of Nano ZnO. The response surface method was utilized to explore the significance of the three most influential factors—solid–liquid ratio, cavitation number, and position height—on the carbonization rate and specific surface area. The products were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), laser particle size analysis, and specific surface area analysis. The results showed that the optimal process parameters were a reaction temperature of 80 °C, a reaction time of 120 min, a solid–liquid ratio of 5.011:100, a calcination temperature of 500 °C for 1 h, an incident angle of 60°, a cavitation number of 0.366, and a position height of 301.128 mm. The interaction between solid–liquid ratio and position height significantly influenced the process parameter variations. Under these conditions, the specific surface area and carbonization rate were 63.190 m²/g and 94.623%, respectively. The carbonized product was flaky Nano ZnO with good dispersion and small particle size. Compared to traditional mechanical stirring and bubbling methods, the specific surface area increased by 1.5 times, the carbonization rate improved by 10%, and the particle size decreased by half, significantly enhancing the product performance. Full article

This research explored the application of cotton straw fiber in asphalt mixtures, aiming to optimize the asphalt mixtures’ performance. Firstly, 17 experiments were designed using Response Surface Methodology (RSM). Subsequently, the Box–Behnken Design (BBD) was used to examine how the asphalt content, fiber length, and cotton straw fiber content interacted to affect the modified asphalt mixes’ pavement performance. Based on the experimental findings, performance prediction models were created to direct optimization. The optimized design was then validated through pavement performance tests and bending fatigue tests. The findings revealed that cotton straw fiber content, length, and asphalt content significantly influence the performance of modified asphalt mixtures. The inclusion of cotton straw fibers enhanced various properties of the mixtures. When the fiber content was set at 0.3%, fiber length at 6 mm, and asphalt content at 5.3%, the response indicators, including Marshall stability, dynamic stability, flexural strength, and freeze–thaw strength ratio, were measured at 12.246 kN, 2452.396 times/mm, 12.30 MPa, and 92.76%, respectively. These results indicate that the cotton-straw-fiber-modified asphalt mixture achieved optimal performance while meeting regulatory requirements. Additionally, fatigue tests showed that the cotton-straw-fiber-modified asphalt mixture exhibited superior fatigue resistance compared with the SBS-modified asphalt mixture. The maximum error between the RSM predictions and the experimental measurements was within 10%, demonstrating the accuracy of the predictive models in estimating the impact of different factors on asphalt mixture performance. The application of RSM in designing and optimizing cotton-straw-fiber-modified asphalt mixtures proved to be highly effective, offering valuable insights for utilizing cotton straw fibers in road construction. Full article

This study investigated the combined effects of calcium carbide waste (CCW) and lateritic soil (LS) on sustainable concrete’s fresh and mechanical properties as a construction material for infrastructure development. The study will explore the possibility of using easily accessible materials, such as lateritic soils and calcium carbide waste. Therefore, laterite soil was used to replace some portions of fine aggregate at 0% to 40% (interval of 10%) by weight, while CCW substituted the cement content at 0%, 5%, 10%, 15%, and 20% by weight. A response surface methodology/central composite design (RSM/CCD) tool was applied to design and develop statistical models for predicting and optimizing the properties of the sustainable concrete. The LS and CCW were input variables, and compressive strength and splitting tensile properties are response variables. The results indicated that the combined effects of CCW and LS improve workability by 18.2% compared to the control mixture. Regarding the mechanical properties, the synergic effects of CCW as a cementitious material and LS as a fine aggregate have improved the concrete’s compressive and splitting tensile strengths. The contribution of LS is more pronounced than that of CCW. The established models have successfully predicted the mechanical behavior and fresh properties of sustainable concrete utilizing LS and CCW as the independent variables with high accuracy. The optimized responses can be achieved with 15% CCW and 10% lateritic soil as a substitute for fine aggregate weight. These optimization outcomes produced the most robust possible results, with a desirability of 81.3%. Full article

Pulsed electric field (PEF) is one of the emerging technologies that has been applied in many aspects of the food industry. This study examined the impacts of a PEF on the cooking quality, physicochemical properties, nutritional factors, and in vitro protein and starch digestion of two varieties of rice, including Jasmine 105 (white non-glutinous rice) and San Pa Tong 1 (white glutinous rice). Response surface methodology (RSM) and a three-level, three-factor Box–Behnken design were employed to assess the effects of the pulse number, electric field strength, and frequency on cooking time. The findings demonstrated that the number of pulses was a crucial factor influencing cooking time. Under optimal conditions (3347–4345 pulses, electric field strengths of 6–8 kV/cm, and frequencies ranging from 6 to 15 Hz), the rice cooking time was significantly reduced by 40–50% (p < 0.05) when compared to a conventional method. Moreover, PEF-treated rice showed a significant enhancement in in vitro protein and starch digestibility (p < 0.05), as well as retained a higher content of rapidly digestible starch. These results suggested that PEF treatment is a promising green technology for producing a novel quick-cooking rice with an improved eating quality. Full article

The work presents an analysis of the Gorlov helical turbine (GHT) design using both computational fluid dynamics (CFD) simulations and response surface methodology (RSM). The RSM method was applied to investigate the impact of three geometric factors on the turbine’s power coefficient (C_P): the number of blades (N), helix angle ($\gamma$), and aspect ratio (AR). Central composite design (CCD) was used for the design of experiments (DOE). For the CFD simulations, a three-dimensional computational domain was established in the Ansys Fluent software, version 2021R1 utilizing the k-$\omega$ SST turbulence model and the sliding mesh method to perform unsteady flow simulations. The objective function was to achieve the maximum C_P, which was obtained using a high-correlation quadratic mathematical model. Under the optimum conditions, where N, $\gamma$, and AR were 5, 78°, and 0.6, respectively, a C_P value of 0.3072 was achieved. The optimal turbine geometry was validated through experimental testing, and the C_P curve versus tip speed ratio (TSR) was determined and compared with the numerical results, which showed a strong correlation between the two sets of data. Full article

The prevalence of synthetic colorants in commercial products has raised concerns regarding potential risks, including allergic reactions and carcinogenesis, associated with their use or consumption. Natural plant extracts have gained attention as potential alternatives. This research focuses on callus induction and the establishment of cell suspension cultures from Celosia argentea var. plumosa. Friable callus was successfully induced using hypocotyl explants cultured on semi-solid Murashige and Skoog (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.1 mg/L 6-benzylaminopurine (BAP). The friable callus cell line was used to establish a suspension culture. The effects of sucrose, BAP, and tyrosine concentrations on betalain production were investigated using response surface methodology (RSM) based on central composite design (CCD). Optimal conditions (43.88 g/L sucrose, 0.15 mg/L tyrosine, and 0.77 mg/L BAP) yielded 43.87 mg/L total betalain content after 21 days, representing a threefold increase compared to the control. BAP had a significant positive impact on betalain production, and increasing BAP and sucrose concentrations generally led to higher betalain production. However, tyrosine was not a significant factor for betalain production in cell suspension cultures. Additionally, antioxidant assays showed that suspension-cultured cells (SCCs) under optimized conditions exhibited free radical scavenging activity comparable to that observed in C. argentea var. plumosa flower extract. This study indicates the potential for further research on betalain production using C. argentea var. plumosa cell cultures, which may have commercial applications. Full article

Immobilized enzyme reactors (IMERs) are critical tools for developing novel oligosaccharides based on the enzymatic catalysis of polysaccharides. In this paper, a novel glucuronan lyase from Peteryoungia rosettiformans was produced, purified, and then immobilized on a CIM^® CDI disk for cleaving glucuronan. The results showed that around 63.6% of glycuronan lyases (800.9 μg) were immobilized on the disk. The V_max values of immobilized glucuronan lyases did not significantly change (56.9 ± 4.7 μM∙min⁻¹), while the K_m values (0.310 ± 0.075 g∙L⁻¹) increased by 2.5 times. It is worth noting that immobilized glucuronan lyases overcame the catalytic inhibition of free enzymes observed under high glucuronan concentrations (0.5–2 g∙L⁻¹). circumscribed central composite design (CCCD) and response surface methodology (RSM) showed that glucuronan concentration, flow rate, and reaction time significantly affected the yield of oligoglucuronans. The degree of polymerization (DP) of degraded glucuronan ranged from DP 2–8 according to the results obtained by high performance anion exchange chromatography coupled with a pulsed amperometric detector (HPAEC-PAD). The IMER retained 50.9% activity after running 2373 column volumes of glucuronan. Finally, this glucuronan lyase reactor was tentatively connected to an immobilized laccase reactor to depolymerize, and gallic acid (GA) was added to glucuronan. Approximately 8.5 mg of GA was added onto 1 g of initial glucuronan, and the GA–oligoglucuronan conjugates showed notable antioxidant activity. Full article

The solid phase byproduct obtained after conventional fucoidan extraction from the brown seaweed Fucus vesiculosus can be used as a source containing alginate. This study involves ultrasound-assisted extraction (UAE) of alginate from the byproduct using sodium bicarbonate. Response surface methodology (RSM) was applied to obtain the optimum conditions for alginate extraction. The ultrasound (US) treatments included 20 kHz of frequency, 20–91% of amplitude, and an extraction time of 6–34 min. The studied investigated the crude alginate yield (%), molecular weight, and alginate content (%) of the extracts. The optimum conditions for obtaining alginate with low molecular weight were found to be 69% US amplitude and sonication time of 30 min. The alginate extracts obtained were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Ultrasound-assisted extraction involving a short treatment lasting 6–34 min was found to be effective in extracting alginate from the byproduct compared to the conventional extraction of alginate using stirring at 415 rpm and 60 °C for 24 h. The US treatments did not adversely impact the alginate obtained, and the extracted alginates were found to have similar characteristics to the alginate obtained from conventional extraction and commercial sodium alginate. Full article

Ginkgo biloba extract (EGB) has been approved by the Food and Drug Administration in the United States for clinical studies on memory disorders. Ginkgolide B (GB) is the major terpene lactone component of EGB and is a specific and potent antagonist of platelet-activating factor (PAF). In a previous study, we reported the medium composition for the conversion of ginkgolides to GB by Coprinus comatus. In the present study, we applied the response surface methodology (RSM) to optimize the conversion conditions in a 20 L fermenter and applied HPLC-MS/MS, circular dichroism (CD) and infrared (IR) spectroscopy analyses, and nuclear magnetic resonance (NMR) to further confirm the sample structure. The optimal conversion conditions consisted of 12.7 L/min of ventilation, a 156 h conversion time, a 132 rpm rotating speed, a 0.04 MPa fermenter pressure, and a 27.8 °C conversion temperature. Under the optimal conditions, the GB conversion rate was 98.62%, and the GB content of the sample was higher than 98%. HPLC-MS/MS, CD, IR, and NMR analyses showed that the molecular formula of the sample was C₂₀H₂₄O₁₀ and the chemical structure of the sample was in good agreement with the standard GB. Our current study lays the groundwork for the industrial production of GB. Full article