Effect of Different Silane Coupling Agents In-Situ Modified Sepiolite on the Structure and Properties of Natural Rubber Composites Prepared by Latex Compounding Method

With the increasing demand for eco-friendly, non-petroleum-based natural rubber (NR) products, sepiolite, a naturally abundant, one-dimensional clay mineral, has been identified as a suitable material for reinforcing NR through the latex compounding method. To create superior NR/sepiolite composites, three silane coupling agents with different functional groups were used to modify sepiolite in situ via grafting or adsorption during the disaggregation and activation of natural sepiolite, which were subsequently mixed with natural rubber latex (NRL) to prepare the composites. The results showed that the modified sepiolite improved the dispersion and interfacial bonding strength with the rubber matrix. VTES-modified sepiolite containing C=C groups slightly improved the performance but retarded the vulcanization of the NR composites, and MPTES and TESPT-modified sepiolites containing -SH and −S4− groups, respectively, effectively accelerated vulcanization, inducing the composites to form a denser crosslink network structure, and exhibiting excellent dynamic and static properties, such as the modulus at a 300% increase from 8.82 MPa to 16.87 MPa, a tear strength increase from 49.6 N·mm−1 to 60.3 N·mm−1, as well as an improved rolling resistance and abrasive resistance of the composites. These findings demonstrate that modified sepiolite can be used to produce high-quality NR/sepiolite composites with enhanced properties

Influence of Pyrolytic Carbon Black Derived from Waste Tires at Varied Temperatures within an Industrial Continuous Rotating Moving Bed System

Nowadays, waste tires have emerged as one of the most significant sources of environmental pollution. To address this issue, pyrolysis has become a widely adopted method. The continuous rotary kiln reactor has particularly gained popularity in industrial production for pyrolysis due to its suitability. In order to guide the development of new industrial continuous rotary kiln reactors and achieve high-performance pyrolytic carbon black (CBp), this study was conducted to investigate the relationship between the physical and chemical characteristics of CBp and pyrolysis temperature. The elevated-temperature procedure led to a reduction in DBP values from 90 to 70 mL/100 mg, accompanied by a rise in the specific surface area from 63 to 77 m2/g. The augmentation of pyrolysis temperature was noted to induce the agglomeration of CBp particles, thereby negatively impacting their dispersion within polymer matrices. CBp particles at 550 °C exhibited greater structural order, as determined by Raman spectroscopy, which can be attributed to the elevated temperature proximate to the cylinder wall surface. Furthermore, the potential of CBp for reinforcement in natural rubber (NR) was taken into consideration. The pronounced propensity of high-temperature CBps to agglomerate led to uneven dispersion within the polymer, consequently causing heightened heat accumulation and the emergence of the Payne effect. Based on a thorough analysis of the outcomes, the optimal pyrolysis temperature for CBp synthesis within the continuous reactor was ascertained

Integrating Multiple-Try DREAM(ZS) to Model-Based Bayesian Geoacoustic Inversion Applied to Seabed Backscattering Strength Measurements

The key to model-based Bayesian geoacoustic inversion is to solve the posterior probability distributions (PPDs) of parameters. In order to obtain PPDs more efficiently and accurately, the state-of-the-art Markov chain Monte Carlo (MCMC) method, multiple-try differential evolution adaptive Metropolis(ZS) (MT-DREAM(ZS)), is integrated to the inverse problem because of its excellent ability to fully explore the posterior space of parameters. The effective density fluid model (EDFM), which is derived from Biot–Stoll theory to approximate the poroelastic model, and the published field measurements of backscattering strength are adopted to implement the inversion. The results show that part of the parameters can be estimated close to the measured values, and the PPDs obtained by dual-frequency inversion are more concentrated than those of single-frequency inversion because of the use of more measured backscattering strength data. Otherwise, the comparison between the predicted backscattering strength of dual-frequency inversion results and Jackson’s prediction shows that the solutions of the inverse problem are not unique and may have multiple optimal values. Indeed, the difference between the two predictions is essentially the difference in the estimation of the contribution of volume scattering to the total scattering. Nevertheless, both results are reasonable due to the lack of measurement of volume scattering parameters, and the inversion results given by the posterior probabilities based on the limited measurements and the adopted model are still considered to be reliable

Numerical Simulation and Experiment on Pill Coating of Red Clover Seeds under the Action of Vibrating Force Field

In order to solve the problem of the low qualification rate of the pilling and coating of small-grain forage seeds, a vibration force field is introduced to the traditional vertical disk coating machine to promote the mixing of materials and improve the qualification rate of the pilling. Using the typical small-grain forage seed red clover as an example, we used the vibration force field after adding seed powder particles to a coating pot for the theoretical analysis of the force situation, using the discrete element software EDEM to construct a red clover seed simulation model with the coefficient of discretization as the evaluation index. We studied the effects of the rotational speed of the coating pot, the vibration frequency of the pot, the amplitude of the vibration of the pot, and the other operating parameters of the pot on the uniformity of the seed powder mixing, with the pelletization of the pass rate as the physical evaluation standard, using a one-way test to study the effect of operating parameters on the pelletization pass rate. We used the qualified rate as the physical evaluation standard, through a single-factor test, to study the influence of the working parameters on the qualification rate of the pilling. The results show that the simulation test evaluation index of the discrete coefficient and the physical test evaluation index of the pilling qualification rate with the change rule of the working parameters is consistent with the discrete coefficient, and can be used as an indirect evaluation index of the quality of pilling. To further determine the optimal combination of working parameters, a quadratic regression orthogonal design test was conducted with the discrete coefficients as the evaluation index, and the second-order regression equations of the red clover seeds were established and analyzed by ANOVA using Design-Expert software. The study shows that, when the rotational speed of the coating pot is 307.204 rpm, the vibration frequency is 2.526 Hz, and the vibration amplitude of the coating pot is 5.843 mm, the predicted coefficient of dispersion at this time is 8.1%. Simulation using the best combination of parameters to obtain the average value of the dispersion coefficient of 8.4%, relative to the predicted value of 3.7%, indicated that the optimization of the experimental regression model is accurate, and the results obtained for the vibration of small seeds under the conditions of the design of the pellet granulation coating machine and the optimization of the pelletization coating process parameters have a certain degree of reference significance

Calibration of Small-Grain Seed Parameters Based on a BP Neural Network: A Case Study with Red Clover Seeds

In order to enhance the accuracy of discrete element numerical simulations in the processing of small-seed particles, it is essential to calibrate the parameters of seeds within the discrete element software. This study employs a series of physical tests to obtain the physical and contact parameters of red clover seeds. A discrete element model of red clover seeds is established. Plackett–Burman Design, steepest ascent, and Central Composite Design experiments are sequentially conducted. The simulation deviation of the resting angle of red clover seeds is employed as the evaluation criterion for parameter optimization. The results indicate that the coefficients of static friction between red clover seeds, the coefficients of rolling friction between red clover seeds, and the coefficients of static friction between red clover seeds and the steel plates significantly influence the resting angle. Modeling was performed using a backpropagation neural network, a genetic algorithm–optimized BP network, particle swarm optimization, and simulated annealing. It was found that GA-BP ensured both accuracy and stability. Compared to the traditional response surface methodology, GA-BP showed better fitting performance. For the optimized red clover seed simulation, the error between the angle of repose and the physical experiment was 0.98%. This research provides new insights into the calibration of small-grain seed parameters, demonstrating the value of GA-BP for precision modeling

Comparison of Pollen-Collecting Abilities between <i>Apis mellifera</i> L. and <i>Bombus terrestris</i> L. in the Oil Tree Peony Field

The lack of pollinators in the oil tree peony field was a serious problem for the seed yield. In the preliminary studies, we found that the seed rate of oil tree peonies was significantly improved by supplementing bees during the flowering stages in the pollination net room. In addition, the performance of Apis mellifera L. was better than Bombus terrestris L. To understand the interaction relationship between flowering characteristics and the managed bees, and the pollen-collecting ability of different species of bees, the flowering traits and the pollen loaded on bees were measured in this study. We found that the bees visited flowers with preference and they prefer to forage the flowers having pollen with higher viability. The B. terrestris carried more pollen (27,000.00 ± 5613.70 grains) on the body surface than that of the A. mellifera (7690.00 ± 2873.26 grains). The A. mellifera outperformed B. terrestris both in pollen deposition per visit on the stigma and on the pollen transfer efficiency. The viability of pollen on the body surface (67.77% ± 19.06%) and hind legs (92.02% ± 10.74%) of A. mellifera were both significantly higher than that of B. terrestris (31.84% ± 4.84% and 83.77% ± 6.40%). Our study indicated that the quantity and quality of pollen loaded on stigma by A. mellifera were both better than B. terrestris, which provided evidence that the A. mellifera was the effective pollinator pollinating for the oil tree peony in the pollination net room

Calibration and Experimental Studies on the Mixing Parameters of Red Clover Seeds and Coated Powders

The physical and mechanical properties of the materials in the swirling fluidized-bed seed pelleting unit affect the mixing degree of the materials in the pelleting and coating process, which is of great significance to research on pelleting and coating. The problem of discrete particle model parameters affecting CFD-DEM simulation results is addressed. In this paper, red clover seeds (referred to as seeds) and pelletized coating powder (referred to as powder) were used as the research objects, and the JKR. model was selected to calibrate the contact parameters between seeds and powder based on particle amplification theory. With the powder rest angle as the response value, a simulation calibration test was conducted; the parameters with significant effects on the response value were screened based on the Plackett&ndash;Burman test, and the steepest climb test determined the range of factor levels of essential parameters. The Box&ndash;Behnken test was used to establish the curvilinear response surface and quadratic regression equation to determine the best combination of simulation parameters for the powder. The discrete element rest angle was conducted with the best combination of parameters. The error of the test compared with the physical examination was 1%. The particles calibrated by simulation were subjected to the pneumatic suspension velocity test and particle mixing test. The test results matched the physical test results, which further verified the accuracy and applicability of the established discrete element model and parameters for coated powders

Analysis on Agronomic Characters and Quality of Erjingtiao Varieties in Different Production Areas of Sichuan

【Objective】A comprehensive evaluation on germplasm resources of high-quality local Erjingtiao pepper varieties in Sichuan was conducted, with a view to giving full play to their roles in new variety breeding and industrial processing.【Method】Erjingtiao pepper varieties from nine different production areas of Sichuan including Jianyang, Fushun, Xichong, Mianyang, Santai, Jiajiang, Shuangliu, Huidong and Qionglai were selected as the research materials, and their agronomic traits, nutritional quality indexes and flavor characteristics were comprehensively evaluated by field observation, quality detection and electronic nose analysis.【Result】In terms of agronomic traits, there were significant differences among different varieties in the node of first flower, main stem height, stem diameter, plant height, crown length, crown width, leaf length and leaf width. The mean values were 6.83~12.67, 18.08~27.33 cm, 9.08~15.39 mm, 98.17~141.5 cm, 86.33~136.67 cm, 69.75~117.50 cm, 9.62~15.86 cm and 2.74~4.56 cm, respectively. The differences in the appearance of different varieties of fruits were relatively small, the fruit shape indexes were all above 10, with red mature fruits, glossy fruit surface, soft fruit texture and wrinkled fruit skin, which were the typical fruit characteristics of Erjingtiao pepper. However, there was a great difference in fruit length among different varieties, with the longest fruit length of Qionglai Erjingtiao (25.02 cm) and the shortest fruit length of Huidong Erjingtiao (11.23 cm). However, the difference of fruit width was little, ranging from 1.08 to 1.76 cm. In terms of nutritional quality, there were significant differences among different varieties. The variable coefficients were between 8.35 to 45.72, of which capsaicin content had the greatest difference, with the highest content in Qionglai Erjingtiao (0.54 mg/g), and the lowest one in Xichong Erjingtiao (0.13 mg/g). However, except for Jianyang Erjingtiao, with the lowest color value of only 7.35, there was no significant difference in color value among other varieties. Meanwhile, there were some correlations among different quality indexes, and soluble sugar was significantly positively correlated with total protein and Vc, which was conducive to screening pepper varieties with high nutrition. The first three varieties of Erjingtiao with better comprehensive quality traits were selected by membership function analysis. The Qionglai Erjingtiao, ranking first, belonged to the high-spicy and high-nutrient variety, followed by Shuangliu Erjingtiao and Xichong Erjingtiao, belonged to the varieties of medium-spicy and low-spicy with high nutrition, respectively. The fruit flavor characteristics of different Erjingtiao varieties were similar, and only some varieties could be distinguished by electronic nose, but the flavor of the pulp and seed of the same pepper variety could be distinguished well.【Conclusion】The varieties of Erjingtiao pepper in different production areas of Sichuan have formed various agronomic traits and quality characteristics through long-term natural and artificial selection, and they can be screened according to different needs in the process of germplasm resources utilization and product selection

Highly efficient planar perovskite solar cells achieved by simultaneous defect engineering and formation kinetic control

The formation of high quality (good morphology and low defect concentrations) perovskite films is crucial for realizing high-performance perovskite solar cells (PVSCs). Low-temperature processed perovskite films tend to have a high density of defect states, which hinder the enhancement of their device performance. Although various post-treatment methods have been reported to passivate the surface defects of perovskite, the critical issue is that defects inside the bulk film cannot be passivated simultaneously. Here, we demonstrate a new strategy of simultaneously controlling the perovskite formation kinetics and reducing the defects (e.g., unsaturated Pb) for achieving densely packed perovskite films with low defect concentrations. The strategy is realized through incorporating cyano-based small molecules into perovskite precursor. Our results show that the inverted planar-structured PVSCs with the perovskite films formed by the new strategy have significant performance improvement with PCE reaching 20.10%, which is among the highest values of low-temperature processed solar cells. This work provides a new strategy to further improve the quality of low-temperature processed perovskite films and the relevant device performances